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planemo upload commit 2e9511a184a1ca667c7be0c6321a36dc4e3d116d
author jpayne
date Tue, 18 Mar 2025 17:55:14 -0400
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1 /*
2 ** 2001-09-15
3 **
4 ** The author disclaims copyright to this source code. In place of
5 ** a legal notice, here is a blessing:
6 **
7 ** May you do good and not evil.
8 ** May you find forgiveness for yourself and forgive others.
9 ** May you share freely, never taking more than you give.
10 **
11 *************************************************************************
12 ** This header file defines the interface that the SQLite library
13 ** presents to client programs. If a C-function, structure, datatype,
14 ** or constant definition does not appear in this file, then it is
15 ** not a published API of SQLite, is subject to change without
16 ** notice, and should not be referenced by programs that use SQLite.
17 **
18 ** Some of the definitions that are in this file are marked as
19 ** "experimental". Experimental interfaces are normally new
20 ** features recently added to SQLite. We do not anticipate changes
21 ** to experimental interfaces but reserve the right to make minor changes
22 ** if experience from use "in the wild" suggest such changes are prudent.
23 **
24 ** The official C-language API documentation for SQLite is derived
25 ** from comments in this file. This file is the authoritative source
26 ** on how SQLite interfaces are supposed to operate.
27 **
28 ** The name of this file under configuration management is "sqlite.h.in".
29 ** The makefile makes some minor changes to this file (such as inserting
30 ** the version number) and changes its name to "sqlite3.h" as
31 ** part of the build process.
32 */
33 #ifndef SQLITE3_H
34 #define SQLITE3_H
35 #include <stdarg.h> /* Needed for the definition of va_list */
36
37 /*
38 ** Make sure we can call this stuff from C++.
39 */
40 #ifdef __cplusplus
41 extern "C" {
42 #endif
43
44
45 /*
46 ** Facilitate override of interface linkage and calling conventions.
47 ** Be aware that these macros may not be used within this particular
48 ** translation of the amalgamation and its associated header file.
49 **
50 ** The SQLITE_EXTERN and SQLITE_API macros are used to instruct the
51 ** compiler that the target identifier should have external linkage.
52 **
53 ** The SQLITE_CDECL macro is used to set the calling convention for
54 ** public functions that accept a variable number of arguments.
55 **
56 ** The SQLITE_APICALL macro is used to set the calling convention for
57 ** public functions that accept a fixed number of arguments.
58 **
59 ** The SQLITE_STDCALL macro is no longer used and is now deprecated.
60 **
61 ** The SQLITE_CALLBACK macro is used to set the calling convention for
62 ** function pointers.
63 **
64 ** The SQLITE_SYSAPI macro is used to set the calling convention for
65 ** functions provided by the operating system.
66 **
67 ** Currently, the SQLITE_CDECL, SQLITE_APICALL, SQLITE_CALLBACK, and
68 ** SQLITE_SYSAPI macros are used only when building for environments
69 ** that require non-default calling conventions.
70 */
71 #ifndef SQLITE_EXTERN
72 # define SQLITE_EXTERN extern
73 #endif
74 #ifndef SQLITE_API
75 # define SQLITE_API
76 #endif
77 #ifndef SQLITE_CDECL
78 # define SQLITE_CDECL
79 #endif
80 #ifndef SQLITE_APICALL
81 # define SQLITE_APICALL
82 #endif
83 #ifndef SQLITE_STDCALL
84 # define SQLITE_STDCALL SQLITE_APICALL
85 #endif
86 #ifndef SQLITE_CALLBACK
87 # define SQLITE_CALLBACK
88 #endif
89 #ifndef SQLITE_SYSAPI
90 # define SQLITE_SYSAPI
91 #endif
92
93 /*
94 ** These no-op macros are used in front of interfaces to mark those
95 ** interfaces as either deprecated or experimental. New applications
96 ** should not use deprecated interfaces - they are supported for backwards
97 ** compatibility only. Application writers should be aware that
98 ** experimental interfaces are subject to change in point releases.
99 **
100 ** These macros used to resolve to various kinds of compiler magic that
101 ** would generate warning messages when they were used. But that
102 ** compiler magic ended up generating such a flurry of bug reports
103 ** that we have taken it all out and gone back to using simple
104 ** noop macros.
105 */
106 #define SQLITE_DEPRECATED
107 #define SQLITE_EXPERIMENTAL
108
109 /*
110 ** Ensure these symbols were not defined by some previous header file.
111 */
112 #ifdef SQLITE_VERSION
113 # undef SQLITE_VERSION
114 #endif
115 #ifdef SQLITE_VERSION_NUMBER
116 # undef SQLITE_VERSION_NUMBER
117 #endif
118
119 /*
120 ** CAPI3REF: Compile-Time Library Version Numbers
121 **
122 ** ^(The [SQLITE_VERSION] C preprocessor macro in the sqlite3.h header
123 ** evaluates to a string literal that is the SQLite version in the
124 ** format "X.Y.Z" where X is the major version number (always 3 for
125 ** SQLite3) and Y is the minor version number and Z is the release number.)^
126 ** ^(The [SQLITE_VERSION_NUMBER] C preprocessor macro resolves to an integer
127 ** with the value (X*1000000 + Y*1000 + Z) where X, Y, and Z are the same
128 ** numbers used in [SQLITE_VERSION].)^
129 ** The SQLITE_VERSION_NUMBER for any given release of SQLite will also
130 ** be larger than the release from which it is derived. Either Y will
131 ** be held constant and Z will be incremented or else Y will be incremented
132 ** and Z will be reset to zero.
133 **
134 ** Since [version 3.6.18] ([dateof:3.6.18]),
135 ** SQLite source code has been stored in the
136 ** <a href="http://www.fossil-scm.org/">Fossil configuration management
137 ** system</a>. ^The SQLITE_SOURCE_ID macro evaluates to
138 ** a string which identifies a particular check-in of SQLite
139 ** within its configuration management system. ^The SQLITE_SOURCE_ID
140 ** string contains the date and time of the check-in (UTC) and a SHA1
141 ** or SHA3-256 hash of the entire source tree. If the source code has
142 ** been edited in any way since it was last checked in, then the last
143 ** four hexadecimal digits of the hash may be modified.
144 **
145 ** See also: [sqlite3_libversion()],
146 ** [sqlite3_libversion_number()], [sqlite3_sourceid()],
147 ** [sqlite_version()] and [sqlite_source_id()].
148 */
149 #define SQLITE_VERSION "3.46.0"
150 #define SQLITE_VERSION_NUMBER 3046000
151 #define SQLITE_SOURCE_ID "2024-05-23 13:25:27 96c92aba00c8375bc32fafcdf12429c58bd8aabfcadab6683e35bbb9cdebf19e"
152
153 /*
154 ** CAPI3REF: Run-Time Library Version Numbers
155 ** KEYWORDS: sqlite3_version sqlite3_sourceid
156 **
157 ** These interfaces provide the same information as the [SQLITE_VERSION],
158 ** [SQLITE_VERSION_NUMBER], and [SQLITE_SOURCE_ID] C preprocessor macros
159 ** but are associated with the library instead of the header file. ^(Cautious
160 ** programmers might include assert() statements in their application to
161 ** verify that values returned by these interfaces match the macros in
162 ** the header, and thus ensure that the application is
163 ** compiled with matching library and header files.
164 **
165 ** <blockquote><pre>
166 ** assert( sqlite3_libversion_number()==SQLITE_VERSION_NUMBER );
167 ** assert( strncmp(sqlite3_sourceid(),SQLITE_SOURCE_ID,80)==0 );
168 ** assert( strcmp(sqlite3_libversion(),SQLITE_VERSION)==0 );
169 ** </pre></blockquote>)^
170 **
171 ** ^The sqlite3_version[] string constant contains the text of [SQLITE_VERSION]
172 ** macro. ^The sqlite3_libversion() function returns a pointer to the
173 ** to the sqlite3_version[] string constant. The sqlite3_libversion()
174 ** function is provided for use in DLLs since DLL users usually do not have
175 ** direct access to string constants within the DLL. ^The
176 ** sqlite3_libversion_number() function returns an integer equal to
177 ** [SQLITE_VERSION_NUMBER]. ^(The sqlite3_sourceid() function returns
178 ** a pointer to a string constant whose value is the same as the
179 ** [SQLITE_SOURCE_ID] C preprocessor macro. Except if SQLite is built
180 ** using an edited copy of [the amalgamation], then the last four characters
181 ** of the hash might be different from [SQLITE_SOURCE_ID].)^
182 **
183 ** See also: [sqlite_version()] and [sqlite_source_id()].
184 */
185 SQLITE_API SQLITE_EXTERN const char sqlite3_version[];
186 SQLITE_API const char *sqlite3_libversion(void);
187 SQLITE_API const char *sqlite3_sourceid(void);
188 SQLITE_API int sqlite3_libversion_number(void);
189
190 /*
191 ** CAPI3REF: Run-Time Library Compilation Options Diagnostics
192 **
193 ** ^The sqlite3_compileoption_used() function returns 0 or 1
194 ** indicating whether the specified option was defined at
195 ** compile time. ^The SQLITE_ prefix may be omitted from the
196 ** option name passed to sqlite3_compileoption_used().
197 **
198 ** ^The sqlite3_compileoption_get() function allows iterating
199 ** over the list of options that were defined at compile time by
200 ** returning the N-th compile time option string. ^If N is out of range,
201 ** sqlite3_compileoption_get() returns a NULL pointer. ^The SQLITE_
202 ** prefix is omitted from any strings returned by
203 ** sqlite3_compileoption_get().
204 **
205 ** ^Support for the diagnostic functions sqlite3_compileoption_used()
206 ** and sqlite3_compileoption_get() may be omitted by specifying the
207 ** [SQLITE_OMIT_COMPILEOPTION_DIAGS] option at compile time.
208 **
209 ** See also: SQL functions [sqlite_compileoption_used()] and
210 ** [sqlite_compileoption_get()] and the [compile_options pragma].
211 */
212 #ifndef SQLITE_OMIT_COMPILEOPTION_DIAGS
213 SQLITE_API int sqlite3_compileoption_used(const char *zOptName);
214 SQLITE_API const char *sqlite3_compileoption_get(int N);
215 #else
216 # define sqlite3_compileoption_used(X) 0
217 # define sqlite3_compileoption_get(X) ((void*)0)
218 #endif
219
220 /*
221 ** CAPI3REF: Test To See If The Library Is Threadsafe
222 **
223 ** ^The sqlite3_threadsafe() function returns zero if and only if
224 ** SQLite was compiled with mutexing code omitted due to the
225 ** [SQLITE_THREADSAFE] compile-time option being set to 0.
226 **
227 ** SQLite can be compiled with or without mutexes. When
228 ** the [SQLITE_THREADSAFE] C preprocessor macro is 1 or 2, mutexes
229 ** are enabled and SQLite is threadsafe. When the
230 ** [SQLITE_THREADSAFE] macro is 0,
231 ** the mutexes are omitted. Without the mutexes, it is not safe
232 ** to use SQLite concurrently from more than one thread.
233 **
234 ** Enabling mutexes incurs a measurable performance penalty.
235 ** So if speed is of utmost importance, it makes sense to disable
236 ** the mutexes. But for maximum safety, mutexes should be enabled.
237 ** ^The default behavior is for mutexes to be enabled.
238 **
239 ** This interface can be used by an application to make sure that the
240 ** version of SQLite that it is linking against was compiled with
241 ** the desired setting of the [SQLITE_THREADSAFE] macro.
242 **
243 ** This interface only reports on the compile-time mutex setting
244 ** of the [SQLITE_THREADSAFE] flag. If SQLite is compiled with
245 ** SQLITE_THREADSAFE=1 or =2 then mutexes are enabled by default but
246 ** can be fully or partially disabled using a call to [sqlite3_config()]
247 ** with the verbs [SQLITE_CONFIG_SINGLETHREAD], [SQLITE_CONFIG_MULTITHREAD],
248 ** or [SQLITE_CONFIG_SERIALIZED]. ^(The return value of the
249 ** sqlite3_threadsafe() function shows only the compile-time setting of
250 ** thread safety, not any run-time changes to that setting made by
251 ** sqlite3_config(). In other words, the return value from sqlite3_threadsafe()
252 ** is unchanged by calls to sqlite3_config().)^
253 **
254 ** See the [threading mode] documentation for additional information.
255 */
256 SQLITE_API int sqlite3_threadsafe(void);
257
258 /*
259 ** CAPI3REF: Database Connection Handle
260 ** KEYWORDS: {database connection} {database connections}
261 **
262 ** Each open SQLite database is represented by a pointer to an instance of
263 ** the opaque structure named "sqlite3". It is useful to think of an sqlite3
264 ** pointer as an object. The [sqlite3_open()], [sqlite3_open16()], and
265 ** [sqlite3_open_v2()] interfaces are its constructors, and [sqlite3_close()]
266 ** and [sqlite3_close_v2()] are its destructors. There are many other
267 ** interfaces (such as
268 ** [sqlite3_prepare_v2()], [sqlite3_create_function()], and
269 ** [sqlite3_busy_timeout()] to name but three) that are methods on an
270 ** sqlite3 object.
271 */
272 typedef struct sqlite3 sqlite3;
273
274 /*
275 ** CAPI3REF: 64-Bit Integer Types
276 ** KEYWORDS: sqlite_int64 sqlite_uint64
277 **
278 ** Because there is no cross-platform way to specify 64-bit integer types
279 ** SQLite includes typedefs for 64-bit signed and unsigned integers.
280 **
281 ** The sqlite3_int64 and sqlite3_uint64 are the preferred type definitions.
282 ** The sqlite_int64 and sqlite_uint64 types are supported for backwards
283 ** compatibility only.
284 **
285 ** ^The sqlite3_int64 and sqlite_int64 types can store integer values
286 ** between -9223372036854775808 and +9223372036854775807 inclusive. ^The
287 ** sqlite3_uint64 and sqlite_uint64 types can store integer values
288 ** between 0 and +18446744073709551615 inclusive.
289 */
290 #ifdef SQLITE_INT64_TYPE
291 typedef SQLITE_INT64_TYPE sqlite_int64;
292 # ifdef SQLITE_UINT64_TYPE
293 typedef SQLITE_UINT64_TYPE sqlite_uint64;
294 # else
295 typedef unsigned SQLITE_INT64_TYPE sqlite_uint64;
296 # endif
297 #elif defined(_MSC_VER) || defined(__BORLANDC__)
298 typedef __int64 sqlite_int64;
299 typedef unsigned __int64 sqlite_uint64;
300 #else
301 typedef long long int sqlite_int64;
302 typedef unsigned long long int sqlite_uint64;
303 #endif
304 typedef sqlite_int64 sqlite3_int64;
305 typedef sqlite_uint64 sqlite3_uint64;
306
307 /*
308 ** If compiling for a processor that lacks floating point support,
309 ** substitute integer for floating-point.
310 */
311 #ifdef SQLITE_OMIT_FLOATING_POINT
312 # define double sqlite3_int64
313 #endif
314
315 /*
316 ** CAPI3REF: Closing A Database Connection
317 ** DESTRUCTOR: sqlite3
318 **
319 ** ^The sqlite3_close() and sqlite3_close_v2() routines are destructors
320 ** for the [sqlite3] object.
321 ** ^Calls to sqlite3_close() and sqlite3_close_v2() return [SQLITE_OK] if
322 ** the [sqlite3] object is successfully destroyed and all associated
323 ** resources are deallocated.
324 **
325 ** Ideally, applications should [sqlite3_finalize | finalize] all
326 ** [prepared statements], [sqlite3_blob_close | close] all [BLOB handles], and
327 ** [sqlite3_backup_finish | finish] all [sqlite3_backup] objects associated
328 ** with the [sqlite3] object prior to attempting to close the object.
329 ** ^If the database connection is associated with unfinalized prepared
330 ** statements, BLOB handlers, and/or unfinished sqlite3_backup objects then
331 ** sqlite3_close() will leave the database connection open and return
332 ** [SQLITE_BUSY]. ^If sqlite3_close_v2() is called with unfinalized prepared
333 ** statements, unclosed BLOB handlers, and/or unfinished sqlite3_backups,
334 ** it returns [SQLITE_OK] regardless, but instead of deallocating the database
335 ** connection immediately, it marks the database connection as an unusable
336 ** "zombie" and makes arrangements to automatically deallocate the database
337 ** connection after all prepared statements are finalized, all BLOB handles
338 ** are closed, and all backups have finished. The sqlite3_close_v2() interface
339 ** is intended for use with host languages that are garbage collected, and
340 ** where the order in which destructors are called is arbitrary.
341 **
342 ** ^If an [sqlite3] object is destroyed while a transaction is open,
343 ** the transaction is automatically rolled back.
344 **
345 ** The C parameter to [sqlite3_close(C)] and [sqlite3_close_v2(C)]
346 ** must be either a NULL
347 ** pointer or an [sqlite3] object pointer obtained
348 ** from [sqlite3_open()], [sqlite3_open16()], or
349 ** [sqlite3_open_v2()], and not previously closed.
350 ** ^Calling sqlite3_close() or sqlite3_close_v2() with a NULL pointer
351 ** argument is a harmless no-op.
352 */
353 SQLITE_API int sqlite3_close(sqlite3*);
354 SQLITE_API int sqlite3_close_v2(sqlite3*);
355
356 /*
357 ** The type for a callback function.
358 ** This is legacy and deprecated. It is included for historical
359 ** compatibility and is not documented.
360 */
361 typedef int (*sqlite3_callback)(void*,int,char**, char**);
362
363 /*
364 ** CAPI3REF: One-Step Query Execution Interface
365 ** METHOD: sqlite3
366 **
367 ** The sqlite3_exec() interface is a convenience wrapper around
368 ** [sqlite3_prepare_v2()], [sqlite3_step()], and [sqlite3_finalize()],
369 ** that allows an application to run multiple statements of SQL
370 ** without having to use a lot of C code.
371 **
372 ** ^The sqlite3_exec() interface runs zero or more UTF-8 encoded,
373 ** semicolon-separate SQL statements passed into its 2nd argument,
374 ** in the context of the [database connection] passed in as its 1st
375 ** argument. ^If the callback function of the 3rd argument to
376 ** sqlite3_exec() is not NULL, then it is invoked for each result row
377 ** coming out of the evaluated SQL statements. ^The 4th argument to
378 ** sqlite3_exec() is relayed through to the 1st argument of each
379 ** callback invocation. ^If the callback pointer to sqlite3_exec()
380 ** is NULL, then no callback is ever invoked and result rows are
381 ** ignored.
382 **
383 ** ^If an error occurs while evaluating the SQL statements passed into
384 ** sqlite3_exec(), then execution of the current statement stops and
385 ** subsequent statements are skipped. ^If the 5th parameter to sqlite3_exec()
386 ** is not NULL then any error message is written into memory obtained
387 ** from [sqlite3_malloc()] and passed back through the 5th parameter.
388 ** To avoid memory leaks, the application should invoke [sqlite3_free()]
389 ** on error message strings returned through the 5th parameter of
390 ** sqlite3_exec() after the error message string is no longer needed.
391 ** ^If the 5th parameter to sqlite3_exec() is not NULL and no errors
392 ** occur, then sqlite3_exec() sets the pointer in its 5th parameter to
393 ** NULL before returning.
394 **
395 ** ^If an sqlite3_exec() callback returns non-zero, the sqlite3_exec()
396 ** routine returns SQLITE_ABORT without invoking the callback again and
397 ** without running any subsequent SQL statements.
398 **
399 ** ^The 2nd argument to the sqlite3_exec() callback function is the
400 ** number of columns in the result. ^The 3rd argument to the sqlite3_exec()
401 ** callback is an array of pointers to strings obtained as if from
402 ** [sqlite3_column_text()], one for each column. ^If an element of a
403 ** result row is NULL then the corresponding string pointer for the
404 ** sqlite3_exec() callback is a NULL pointer. ^The 4th argument to the
405 ** sqlite3_exec() callback is an array of pointers to strings where each
406 ** entry represents the name of corresponding result column as obtained
407 ** from [sqlite3_column_name()].
408 **
409 ** ^If the 2nd parameter to sqlite3_exec() is a NULL pointer, a pointer
410 ** to an empty string, or a pointer that contains only whitespace and/or
411 ** SQL comments, then no SQL statements are evaluated and the database
412 ** is not changed.
413 **
414 ** Restrictions:
415 **
416 ** <ul>
417 ** <li> The application must ensure that the 1st parameter to sqlite3_exec()
418 ** is a valid and open [database connection].
419 ** <li> The application must not close the [database connection] specified by
420 ** the 1st parameter to sqlite3_exec() while sqlite3_exec() is running.
421 ** <li> The application must not modify the SQL statement text passed into
422 ** the 2nd parameter of sqlite3_exec() while sqlite3_exec() is running.
423 ** <li> The application must not dereference the arrays or string pointers
424 ** passed as the 3rd and 4th callback parameters after it returns.
425 ** </ul>
426 */
427 SQLITE_API int sqlite3_exec(
428 sqlite3*, /* An open database */
429 const char *sql, /* SQL to be evaluated */
430 int (*callback)(void*,int,char**,char**), /* Callback function */
431 void *, /* 1st argument to callback */
432 char **errmsg /* Error msg written here */
433 );
434
435 /*
436 ** CAPI3REF: Result Codes
437 ** KEYWORDS: {result code definitions}
438 **
439 ** Many SQLite functions return an integer result code from the set shown
440 ** here in order to indicate success or failure.
441 **
442 ** New error codes may be added in future versions of SQLite.
443 **
444 ** See also: [extended result code definitions]
445 */
446 #define SQLITE_OK 0 /* Successful result */
447 /* beginning-of-error-codes */
448 #define SQLITE_ERROR 1 /* Generic error */
449 #define SQLITE_INTERNAL 2 /* Internal logic error in SQLite */
450 #define SQLITE_PERM 3 /* Access permission denied */
451 #define SQLITE_ABORT 4 /* Callback routine requested an abort */
452 #define SQLITE_BUSY 5 /* The database file is locked */
453 #define SQLITE_LOCKED 6 /* A table in the database is locked */
454 #define SQLITE_NOMEM 7 /* A malloc() failed */
455 #define SQLITE_READONLY 8 /* Attempt to write a readonly database */
456 #define SQLITE_INTERRUPT 9 /* Operation terminated by sqlite3_interrupt()*/
457 #define SQLITE_IOERR 10 /* Some kind of disk I/O error occurred */
458 #define SQLITE_CORRUPT 11 /* The database disk image is malformed */
459 #define SQLITE_NOTFOUND 12 /* Unknown opcode in sqlite3_file_control() */
460 #define SQLITE_FULL 13 /* Insertion failed because database is full */
461 #define SQLITE_CANTOPEN 14 /* Unable to open the database file */
462 #define SQLITE_PROTOCOL 15 /* Database lock protocol error */
463 #define SQLITE_EMPTY 16 /* Internal use only */
464 #define SQLITE_SCHEMA 17 /* The database schema changed */
465 #define SQLITE_TOOBIG 18 /* String or BLOB exceeds size limit */
466 #define SQLITE_CONSTRAINT 19 /* Abort due to constraint violation */
467 #define SQLITE_MISMATCH 20 /* Data type mismatch */
468 #define SQLITE_MISUSE 21 /* Library used incorrectly */
469 #define SQLITE_NOLFS 22 /* Uses OS features not supported on host */
470 #define SQLITE_AUTH 23 /* Authorization denied */
471 #define SQLITE_FORMAT 24 /* Not used */
472 #define SQLITE_RANGE 25 /* 2nd parameter to sqlite3_bind out of range */
473 #define SQLITE_NOTADB 26 /* File opened that is not a database file */
474 #define SQLITE_NOTICE 27 /* Notifications from sqlite3_log() */
475 #define SQLITE_WARNING 28 /* Warnings from sqlite3_log() */
476 #define SQLITE_ROW 100 /* sqlite3_step() has another row ready */
477 #define SQLITE_DONE 101 /* sqlite3_step() has finished executing */
478 /* end-of-error-codes */
479
480 /*
481 ** CAPI3REF: Extended Result Codes
482 ** KEYWORDS: {extended result code definitions}
483 **
484 ** In its default configuration, SQLite API routines return one of 30 integer
485 ** [result codes]. However, experience has shown that many of
486 ** these result codes are too coarse-grained. They do not provide as
487 ** much information about problems as programmers might like. In an effort to
488 ** address this, newer versions of SQLite (version 3.3.8 [dateof:3.3.8]
489 ** and later) include
490 ** support for additional result codes that provide more detailed information
491 ** about errors. These [extended result codes] are enabled or disabled
492 ** on a per database connection basis using the
493 ** [sqlite3_extended_result_codes()] API. Or, the extended code for
494 ** the most recent error can be obtained using
495 ** [sqlite3_extended_errcode()].
496 */
497 #define SQLITE_ERROR_MISSING_COLLSEQ (SQLITE_ERROR | (1<<8))
498 #define SQLITE_ERROR_RETRY (SQLITE_ERROR | (2<<8))
499 #define SQLITE_ERROR_SNAPSHOT (SQLITE_ERROR | (3<<8))
500 #define SQLITE_IOERR_READ (SQLITE_IOERR | (1<<8))
501 #define SQLITE_IOERR_SHORT_READ (SQLITE_IOERR | (2<<8))
502 #define SQLITE_IOERR_WRITE (SQLITE_IOERR | (3<<8))
503 #define SQLITE_IOERR_FSYNC (SQLITE_IOERR | (4<<8))
504 #define SQLITE_IOERR_DIR_FSYNC (SQLITE_IOERR | (5<<8))
505 #define SQLITE_IOERR_TRUNCATE (SQLITE_IOERR | (6<<8))
506 #define SQLITE_IOERR_FSTAT (SQLITE_IOERR | (7<<8))
507 #define SQLITE_IOERR_UNLOCK (SQLITE_IOERR | (8<<8))
508 #define SQLITE_IOERR_RDLOCK (SQLITE_IOERR | (9<<8))
509 #define SQLITE_IOERR_DELETE (SQLITE_IOERR | (10<<8))
510 #define SQLITE_IOERR_BLOCKED (SQLITE_IOERR | (11<<8))
511 #define SQLITE_IOERR_NOMEM (SQLITE_IOERR | (12<<8))
512 #define SQLITE_IOERR_ACCESS (SQLITE_IOERR | (13<<8))
513 #define SQLITE_IOERR_CHECKRESERVEDLOCK (SQLITE_IOERR | (14<<8))
514 #define SQLITE_IOERR_LOCK (SQLITE_IOERR | (15<<8))
515 #define SQLITE_IOERR_CLOSE (SQLITE_IOERR | (16<<8))
516 #define SQLITE_IOERR_DIR_CLOSE (SQLITE_IOERR | (17<<8))
517 #define SQLITE_IOERR_SHMOPEN (SQLITE_IOERR | (18<<8))
518 #define SQLITE_IOERR_SHMSIZE (SQLITE_IOERR | (19<<8))
519 #define SQLITE_IOERR_SHMLOCK (SQLITE_IOERR | (20<<8))
520 #define SQLITE_IOERR_SHMMAP (SQLITE_IOERR | (21<<8))
521 #define SQLITE_IOERR_SEEK (SQLITE_IOERR | (22<<8))
522 #define SQLITE_IOERR_DELETE_NOENT (SQLITE_IOERR | (23<<8))
523 #define SQLITE_IOERR_MMAP (SQLITE_IOERR | (24<<8))
524 #define SQLITE_IOERR_GETTEMPPATH (SQLITE_IOERR | (25<<8))
525 #define SQLITE_IOERR_CONVPATH (SQLITE_IOERR | (26<<8))
526 #define SQLITE_IOERR_VNODE (SQLITE_IOERR | (27<<8))
527 #define SQLITE_IOERR_AUTH (SQLITE_IOERR | (28<<8))
528 #define SQLITE_IOERR_BEGIN_ATOMIC (SQLITE_IOERR | (29<<8))
529 #define SQLITE_IOERR_COMMIT_ATOMIC (SQLITE_IOERR | (30<<8))
530 #define SQLITE_IOERR_ROLLBACK_ATOMIC (SQLITE_IOERR | (31<<8))
531 #define SQLITE_IOERR_DATA (SQLITE_IOERR | (32<<8))
532 #define SQLITE_IOERR_CORRUPTFS (SQLITE_IOERR | (33<<8))
533 #define SQLITE_IOERR_IN_PAGE (SQLITE_IOERR | (34<<8))
534 #define SQLITE_LOCKED_SHAREDCACHE (SQLITE_LOCKED | (1<<8))
535 #define SQLITE_LOCKED_VTAB (SQLITE_LOCKED | (2<<8))
536 #define SQLITE_BUSY_RECOVERY (SQLITE_BUSY | (1<<8))
537 #define SQLITE_BUSY_SNAPSHOT (SQLITE_BUSY | (2<<8))
538 #define SQLITE_BUSY_TIMEOUT (SQLITE_BUSY | (3<<8))
539 #define SQLITE_CANTOPEN_NOTEMPDIR (SQLITE_CANTOPEN | (1<<8))
540 #define SQLITE_CANTOPEN_ISDIR (SQLITE_CANTOPEN | (2<<8))
541 #define SQLITE_CANTOPEN_FULLPATH (SQLITE_CANTOPEN | (3<<8))
542 #define SQLITE_CANTOPEN_CONVPATH (SQLITE_CANTOPEN | (4<<8))
543 #define SQLITE_CANTOPEN_DIRTYWAL (SQLITE_CANTOPEN | (5<<8)) /* Not Used */
544 #define SQLITE_CANTOPEN_SYMLINK (SQLITE_CANTOPEN | (6<<8))
545 #define SQLITE_CORRUPT_VTAB (SQLITE_CORRUPT | (1<<8))
546 #define SQLITE_CORRUPT_SEQUENCE (SQLITE_CORRUPT | (2<<8))
547 #define SQLITE_CORRUPT_INDEX (SQLITE_CORRUPT | (3<<8))
548 #define SQLITE_READONLY_RECOVERY (SQLITE_READONLY | (1<<8))
549 #define SQLITE_READONLY_CANTLOCK (SQLITE_READONLY | (2<<8))
550 #define SQLITE_READONLY_ROLLBACK (SQLITE_READONLY | (3<<8))
551 #define SQLITE_READONLY_DBMOVED (SQLITE_READONLY | (4<<8))
552 #define SQLITE_READONLY_CANTINIT (SQLITE_READONLY | (5<<8))
553 #define SQLITE_READONLY_DIRECTORY (SQLITE_READONLY | (6<<8))
554 #define SQLITE_ABORT_ROLLBACK (SQLITE_ABORT | (2<<8))
555 #define SQLITE_CONSTRAINT_CHECK (SQLITE_CONSTRAINT | (1<<8))
556 #define SQLITE_CONSTRAINT_COMMITHOOK (SQLITE_CONSTRAINT | (2<<8))
557 #define SQLITE_CONSTRAINT_FOREIGNKEY (SQLITE_CONSTRAINT | (3<<8))
558 #define SQLITE_CONSTRAINT_FUNCTION (SQLITE_CONSTRAINT | (4<<8))
559 #define SQLITE_CONSTRAINT_NOTNULL (SQLITE_CONSTRAINT | (5<<8))
560 #define SQLITE_CONSTRAINT_PRIMARYKEY (SQLITE_CONSTRAINT | (6<<8))
561 #define SQLITE_CONSTRAINT_TRIGGER (SQLITE_CONSTRAINT | (7<<8))
562 #define SQLITE_CONSTRAINT_UNIQUE (SQLITE_CONSTRAINT | (8<<8))
563 #define SQLITE_CONSTRAINT_VTAB (SQLITE_CONSTRAINT | (9<<8))
564 #define SQLITE_CONSTRAINT_ROWID (SQLITE_CONSTRAINT |(10<<8))
565 #define SQLITE_CONSTRAINT_PINNED (SQLITE_CONSTRAINT |(11<<8))
566 #define SQLITE_CONSTRAINT_DATATYPE (SQLITE_CONSTRAINT |(12<<8))
567 #define SQLITE_NOTICE_RECOVER_WAL (SQLITE_NOTICE | (1<<8))
568 #define SQLITE_NOTICE_RECOVER_ROLLBACK (SQLITE_NOTICE | (2<<8))
569 #define SQLITE_NOTICE_RBU (SQLITE_NOTICE | (3<<8))
570 #define SQLITE_WARNING_AUTOINDEX (SQLITE_WARNING | (1<<8))
571 #define SQLITE_AUTH_USER (SQLITE_AUTH | (1<<8))
572 #define SQLITE_OK_LOAD_PERMANENTLY (SQLITE_OK | (1<<8))
573 #define SQLITE_OK_SYMLINK (SQLITE_OK | (2<<8)) /* internal use only */
574
575 /*
576 ** CAPI3REF: Flags For File Open Operations
577 **
578 ** These bit values are intended for use in the
579 ** 3rd parameter to the [sqlite3_open_v2()] interface and
580 ** in the 4th parameter to the [sqlite3_vfs.xOpen] method.
581 **
582 ** Only those flags marked as "Ok for sqlite3_open_v2()" may be
583 ** used as the third argument to the [sqlite3_open_v2()] interface.
584 ** The other flags have historically been ignored by sqlite3_open_v2(),
585 ** though future versions of SQLite might change so that an error is
586 ** raised if any of the disallowed bits are passed into sqlite3_open_v2().
587 ** Applications should not depend on the historical behavior.
588 **
589 ** Note in particular that passing the SQLITE_OPEN_EXCLUSIVE flag into
590 ** [sqlite3_open_v2()] does *not* cause the underlying database file
591 ** to be opened using O_EXCL. Passing SQLITE_OPEN_EXCLUSIVE into
592 ** [sqlite3_open_v2()] has historically be a no-op and might become an
593 ** error in future versions of SQLite.
594 */
595 #define SQLITE_OPEN_READONLY 0x00000001 /* Ok for sqlite3_open_v2() */
596 #define SQLITE_OPEN_READWRITE 0x00000002 /* Ok for sqlite3_open_v2() */
597 #define SQLITE_OPEN_CREATE 0x00000004 /* Ok for sqlite3_open_v2() */
598 #define SQLITE_OPEN_DELETEONCLOSE 0x00000008 /* VFS only */
599 #define SQLITE_OPEN_EXCLUSIVE 0x00000010 /* VFS only */
600 #define SQLITE_OPEN_AUTOPROXY 0x00000020 /* VFS only */
601 #define SQLITE_OPEN_URI 0x00000040 /* Ok for sqlite3_open_v2() */
602 #define SQLITE_OPEN_MEMORY 0x00000080 /* Ok for sqlite3_open_v2() */
603 #define SQLITE_OPEN_MAIN_DB 0x00000100 /* VFS only */
604 #define SQLITE_OPEN_TEMP_DB 0x00000200 /* VFS only */
605 #define SQLITE_OPEN_TRANSIENT_DB 0x00000400 /* VFS only */
606 #define SQLITE_OPEN_MAIN_JOURNAL 0x00000800 /* VFS only */
607 #define SQLITE_OPEN_TEMP_JOURNAL 0x00001000 /* VFS only */
608 #define SQLITE_OPEN_SUBJOURNAL 0x00002000 /* VFS only */
609 #define SQLITE_OPEN_SUPER_JOURNAL 0x00004000 /* VFS only */
610 #define SQLITE_OPEN_NOMUTEX 0x00008000 /* Ok for sqlite3_open_v2() */
611 #define SQLITE_OPEN_FULLMUTEX 0x00010000 /* Ok for sqlite3_open_v2() */
612 #define SQLITE_OPEN_SHAREDCACHE 0x00020000 /* Ok for sqlite3_open_v2() */
613 #define SQLITE_OPEN_PRIVATECACHE 0x00040000 /* Ok for sqlite3_open_v2() */
614 #define SQLITE_OPEN_WAL 0x00080000 /* VFS only */
615 #define SQLITE_OPEN_NOFOLLOW 0x01000000 /* Ok for sqlite3_open_v2() */
616 #define SQLITE_OPEN_EXRESCODE 0x02000000 /* Extended result codes */
617
618 /* Reserved: 0x00F00000 */
619 /* Legacy compatibility: */
620 #define SQLITE_OPEN_MASTER_JOURNAL 0x00004000 /* VFS only */
621
622
623 /*
624 ** CAPI3REF: Device Characteristics
625 **
626 ** The xDeviceCharacteristics method of the [sqlite3_io_methods]
627 ** object returns an integer which is a vector of these
628 ** bit values expressing I/O characteristics of the mass storage
629 ** device that holds the file that the [sqlite3_io_methods]
630 ** refers to.
631 **
632 ** The SQLITE_IOCAP_ATOMIC property means that all writes of
633 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
634 ** mean that writes of blocks that are nnn bytes in size and
635 ** are aligned to an address which is an integer multiple of
636 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
637 ** that when data is appended to a file, the data is appended
638 ** first then the size of the file is extended, never the other
639 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
640 ** information is written to disk in the same order as calls
641 ** to xWrite(). The SQLITE_IOCAP_POWERSAFE_OVERWRITE property means that
642 ** after reboot following a crash or power loss, the only bytes in a
643 ** file that were written at the application level might have changed
644 ** and that adjacent bytes, even bytes within the same sector are
645 ** guaranteed to be unchanged. The SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN
646 ** flag indicates that a file cannot be deleted when open. The
647 ** SQLITE_IOCAP_IMMUTABLE flag indicates that the file is on
648 ** read-only media and cannot be changed even by processes with
649 ** elevated privileges.
650 **
651 ** The SQLITE_IOCAP_BATCH_ATOMIC property means that the underlying
652 ** filesystem supports doing multiple write operations atomically when those
653 ** write operations are bracketed by [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] and
654 ** [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE].
655 */
656 #define SQLITE_IOCAP_ATOMIC 0x00000001
657 #define SQLITE_IOCAP_ATOMIC512 0x00000002
658 #define SQLITE_IOCAP_ATOMIC1K 0x00000004
659 #define SQLITE_IOCAP_ATOMIC2K 0x00000008
660 #define SQLITE_IOCAP_ATOMIC4K 0x00000010
661 #define SQLITE_IOCAP_ATOMIC8K 0x00000020
662 #define SQLITE_IOCAP_ATOMIC16K 0x00000040
663 #define SQLITE_IOCAP_ATOMIC32K 0x00000080
664 #define SQLITE_IOCAP_ATOMIC64K 0x00000100
665 #define SQLITE_IOCAP_SAFE_APPEND 0x00000200
666 #define SQLITE_IOCAP_SEQUENTIAL 0x00000400
667 #define SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN 0x00000800
668 #define SQLITE_IOCAP_POWERSAFE_OVERWRITE 0x00001000
669 #define SQLITE_IOCAP_IMMUTABLE 0x00002000
670 #define SQLITE_IOCAP_BATCH_ATOMIC 0x00004000
671
672 /*
673 ** CAPI3REF: File Locking Levels
674 **
675 ** SQLite uses one of these integer values as the second
676 ** argument to calls it makes to the xLock() and xUnlock() methods
677 ** of an [sqlite3_io_methods] object. These values are ordered from
678 ** lest restrictive to most restrictive.
679 **
680 ** The argument to xLock() is always SHARED or higher. The argument to
681 ** xUnlock is either SHARED or NONE.
682 */
683 #define SQLITE_LOCK_NONE 0 /* xUnlock() only */
684 #define SQLITE_LOCK_SHARED 1 /* xLock() or xUnlock() */
685 #define SQLITE_LOCK_RESERVED 2 /* xLock() only */
686 #define SQLITE_LOCK_PENDING 3 /* xLock() only */
687 #define SQLITE_LOCK_EXCLUSIVE 4 /* xLock() only */
688
689 /*
690 ** CAPI3REF: Synchronization Type Flags
691 **
692 ** When SQLite invokes the xSync() method of an
693 ** [sqlite3_io_methods] object it uses a combination of
694 ** these integer values as the second argument.
695 **
696 ** When the SQLITE_SYNC_DATAONLY flag is used, it means that the
697 ** sync operation only needs to flush data to mass storage. Inode
698 ** information need not be flushed. If the lower four bits of the flag
699 ** equal SQLITE_SYNC_NORMAL, that means to use normal fsync() semantics.
700 ** If the lower four bits equal SQLITE_SYNC_FULL, that means
701 ** to use Mac OS X style fullsync instead of fsync().
702 **
703 ** Do not confuse the SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags
704 ** with the [PRAGMA synchronous]=NORMAL and [PRAGMA synchronous]=FULL
705 ** settings. The [synchronous pragma] determines when calls to the
706 ** xSync VFS method occur and applies uniformly across all platforms.
707 ** The SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL flags determine how
708 ** energetic or rigorous or forceful the sync operations are and
709 ** only make a difference on Mac OSX for the default SQLite code.
710 ** (Third-party VFS implementations might also make the distinction
711 ** between SQLITE_SYNC_NORMAL and SQLITE_SYNC_FULL, but among the
712 ** operating systems natively supported by SQLite, only Mac OSX
713 ** cares about the difference.)
714 */
715 #define SQLITE_SYNC_NORMAL 0x00002
716 #define SQLITE_SYNC_FULL 0x00003
717 #define SQLITE_SYNC_DATAONLY 0x00010
718
719 /*
720 ** CAPI3REF: OS Interface Open File Handle
721 **
722 ** An [sqlite3_file] object represents an open file in the
723 ** [sqlite3_vfs | OS interface layer]. Individual OS interface
724 ** implementations will
725 ** want to subclass this object by appending additional fields
726 ** for their own use. The pMethods entry is a pointer to an
727 ** [sqlite3_io_methods] object that defines methods for performing
728 ** I/O operations on the open file.
729 */
730 typedef struct sqlite3_file sqlite3_file;
731 struct sqlite3_file {
732 const struct sqlite3_io_methods *pMethods; /* Methods for an open file */
733 };
734
735 /*
736 ** CAPI3REF: OS Interface File Virtual Methods Object
737 **
738 ** Every file opened by the [sqlite3_vfs.xOpen] method populates an
739 ** [sqlite3_file] object (or, more commonly, a subclass of the
740 ** [sqlite3_file] object) with a pointer to an instance of this object.
741 ** This object defines the methods used to perform various operations
742 ** against the open file represented by the [sqlite3_file] object.
743 **
744 ** If the [sqlite3_vfs.xOpen] method sets the sqlite3_file.pMethods element
745 ** to a non-NULL pointer, then the sqlite3_io_methods.xClose method
746 ** may be invoked even if the [sqlite3_vfs.xOpen] reported that it failed. The
747 ** only way to prevent a call to xClose following a failed [sqlite3_vfs.xOpen]
748 ** is for the [sqlite3_vfs.xOpen] to set the sqlite3_file.pMethods element
749 ** to NULL.
750 **
751 ** The flags argument to xSync may be one of [SQLITE_SYNC_NORMAL] or
752 ** [SQLITE_SYNC_FULL]. The first choice is the normal fsync().
753 ** The second choice is a Mac OS X style fullsync. The [SQLITE_SYNC_DATAONLY]
754 ** flag may be ORed in to indicate that only the data of the file
755 ** and not its inode needs to be synced.
756 **
757 ** The integer values to xLock() and xUnlock() are one of
758 ** <ul>
759 ** <li> [SQLITE_LOCK_NONE],
760 ** <li> [SQLITE_LOCK_SHARED],
761 ** <li> [SQLITE_LOCK_RESERVED],
762 ** <li> [SQLITE_LOCK_PENDING], or
763 ** <li> [SQLITE_LOCK_EXCLUSIVE].
764 ** </ul>
765 ** xLock() upgrades the database file lock. In other words, xLock() moves the
766 ** database file lock in the direction NONE toward EXCLUSIVE. The argument to
767 ** xLock() is always one of SHARED, RESERVED, PENDING, or EXCLUSIVE, never
768 ** SQLITE_LOCK_NONE. If the database file lock is already at or above the
769 ** requested lock, then the call to xLock() is a no-op.
770 ** xUnlock() downgrades the database file lock to either SHARED or NONE.
771 ** If the lock is already at or below the requested lock state, then the call
772 ** to xUnlock() is a no-op.
773 ** The xCheckReservedLock() method checks whether any database connection,
774 ** either in this process or in some other process, is holding a RESERVED,
775 ** PENDING, or EXCLUSIVE lock on the file. It returns true
776 ** if such a lock exists and false otherwise.
777 **
778 ** The xFileControl() method is a generic interface that allows custom
779 ** VFS implementations to directly control an open file using the
780 ** [sqlite3_file_control()] interface. The second "op" argument is an
781 ** integer opcode. The third argument is a generic pointer intended to
782 ** point to a structure that may contain arguments or space in which to
783 ** write return values. Potential uses for xFileControl() might be
784 ** functions to enable blocking locks with timeouts, to change the
785 ** locking strategy (for example to use dot-file locks), to inquire
786 ** about the status of a lock, or to break stale locks. The SQLite
787 ** core reserves all opcodes less than 100 for its own use.
788 ** A [file control opcodes | list of opcodes] less than 100 is available.
789 ** Applications that define a custom xFileControl method should use opcodes
790 ** greater than 100 to avoid conflicts. VFS implementations should
791 ** return [SQLITE_NOTFOUND] for file control opcodes that they do not
792 ** recognize.
793 **
794 ** The xSectorSize() method returns the sector size of the
795 ** device that underlies the file. The sector size is the
796 ** minimum write that can be performed without disturbing
797 ** other bytes in the file. The xDeviceCharacteristics()
798 ** method returns a bit vector describing behaviors of the
799 ** underlying device:
800 **
801 ** <ul>
802 ** <li> [SQLITE_IOCAP_ATOMIC]
803 ** <li> [SQLITE_IOCAP_ATOMIC512]
804 ** <li> [SQLITE_IOCAP_ATOMIC1K]
805 ** <li> [SQLITE_IOCAP_ATOMIC2K]
806 ** <li> [SQLITE_IOCAP_ATOMIC4K]
807 ** <li> [SQLITE_IOCAP_ATOMIC8K]
808 ** <li> [SQLITE_IOCAP_ATOMIC16K]
809 ** <li> [SQLITE_IOCAP_ATOMIC32K]
810 ** <li> [SQLITE_IOCAP_ATOMIC64K]
811 ** <li> [SQLITE_IOCAP_SAFE_APPEND]
812 ** <li> [SQLITE_IOCAP_SEQUENTIAL]
813 ** <li> [SQLITE_IOCAP_UNDELETABLE_WHEN_OPEN]
814 ** <li> [SQLITE_IOCAP_POWERSAFE_OVERWRITE]
815 ** <li> [SQLITE_IOCAP_IMMUTABLE]
816 ** <li> [SQLITE_IOCAP_BATCH_ATOMIC]
817 ** </ul>
818 **
819 ** The SQLITE_IOCAP_ATOMIC property means that all writes of
820 ** any size are atomic. The SQLITE_IOCAP_ATOMICnnn values
821 ** mean that writes of blocks that are nnn bytes in size and
822 ** are aligned to an address which is an integer multiple of
823 ** nnn are atomic. The SQLITE_IOCAP_SAFE_APPEND value means
824 ** that when data is appended to a file, the data is appended
825 ** first then the size of the file is extended, never the other
826 ** way around. The SQLITE_IOCAP_SEQUENTIAL property means that
827 ** information is written to disk in the same order as calls
828 ** to xWrite().
829 **
830 ** If xRead() returns SQLITE_IOERR_SHORT_READ it must also fill
831 ** in the unread portions of the buffer with zeros. A VFS that
832 ** fails to zero-fill short reads might seem to work. However,
833 ** failure to zero-fill short reads will eventually lead to
834 ** database corruption.
835 */
836 typedef struct sqlite3_io_methods sqlite3_io_methods;
837 struct sqlite3_io_methods {
838 int iVersion;
839 int (*xClose)(sqlite3_file*);
840 int (*xRead)(sqlite3_file*, void*, int iAmt, sqlite3_int64 iOfst);
841 int (*xWrite)(sqlite3_file*, const void*, int iAmt, sqlite3_int64 iOfst);
842 int (*xTruncate)(sqlite3_file*, sqlite3_int64 size);
843 int (*xSync)(sqlite3_file*, int flags);
844 int (*xFileSize)(sqlite3_file*, sqlite3_int64 *pSize);
845 int (*xLock)(sqlite3_file*, int);
846 int (*xUnlock)(sqlite3_file*, int);
847 int (*xCheckReservedLock)(sqlite3_file*, int *pResOut);
848 int (*xFileControl)(sqlite3_file*, int op, void *pArg);
849 int (*xSectorSize)(sqlite3_file*);
850 int (*xDeviceCharacteristics)(sqlite3_file*);
851 /* Methods above are valid for version 1 */
852 int (*xShmMap)(sqlite3_file*, int iPg, int pgsz, int, void volatile**);
853 int (*xShmLock)(sqlite3_file*, int offset, int n, int flags);
854 void (*xShmBarrier)(sqlite3_file*);
855 int (*xShmUnmap)(sqlite3_file*, int deleteFlag);
856 /* Methods above are valid for version 2 */
857 int (*xFetch)(sqlite3_file*, sqlite3_int64 iOfst, int iAmt, void **pp);
858 int (*xUnfetch)(sqlite3_file*, sqlite3_int64 iOfst, void *p);
859 /* Methods above are valid for version 3 */
860 /* Additional methods may be added in future releases */
861 };
862
863 /*
864 ** CAPI3REF: Standard File Control Opcodes
865 ** KEYWORDS: {file control opcodes} {file control opcode}
866 **
867 ** These integer constants are opcodes for the xFileControl method
868 ** of the [sqlite3_io_methods] object and for the [sqlite3_file_control()]
869 ** interface.
870 **
871 ** <ul>
872 ** <li>[[SQLITE_FCNTL_LOCKSTATE]]
873 ** The [SQLITE_FCNTL_LOCKSTATE] opcode is used for debugging. This
874 ** opcode causes the xFileControl method to write the current state of
875 ** the lock (one of [SQLITE_LOCK_NONE], [SQLITE_LOCK_SHARED],
876 ** [SQLITE_LOCK_RESERVED], [SQLITE_LOCK_PENDING], or [SQLITE_LOCK_EXCLUSIVE])
877 ** into an integer that the pArg argument points to.
878 ** This capability is only available if SQLite is compiled with [SQLITE_DEBUG].
879 **
880 ** <li>[[SQLITE_FCNTL_SIZE_HINT]]
881 ** The [SQLITE_FCNTL_SIZE_HINT] opcode is used by SQLite to give the VFS
882 ** layer a hint of how large the database file will grow to be during the
883 ** current transaction. This hint is not guaranteed to be accurate but it
884 ** is often close. The underlying VFS might choose to preallocate database
885 ** file space based on this hint in order to help writes to the database
886 ** file run faster.
887 **
888 ** <li>[[SQLITE_FCNTL_SIZE_LIMIT]]
889 ** The [SQLITE_FCNTL_SIZE_LIMIT] opcode is used by in-memory VFS that
890 ** implements [sqlite3_deserialize()] to set an upper bound on the size
891 ** of the in-memory database. The argument is a pointer to a [sqlite3_int64].
892 ** If the integer pointed to is negative, then it is filled in with the
893 ** current limit. Otherwise the limit is set to the larger of the value
894 ** of the integer pointed to and the current database size. The integer
895 ** pointed to is set to the new limit.
896 **
897 ** <li>[[SQLITE_FCNTL_CHUNK_SIZE]]
898 ** The [SQLITE_FCNTL_CHUNK_SIZE] opcode is used to request that the VFS
899 ** extends and truncates the database file in chunks of a size specified
900 ** by the user. The fourth argument to [sqlite3_file_control()] should
901 ** point to an integer (type int) containing the new chunk-size to use
902 ** for the nominated database. Allocating database file space in large
903 ** chunks (say 1MB at a time), may reduce file-system fragmentation and
904 ** improve performance on some systems.
905 **
906 ** <li>[[SQLITE_FCNTL_FILE_POINTER]]
907 ** The [SQLITE_FCNTL_FILE_POINTER] opcode is used to obtain a pointer
908 ** to the [sqlite3_file] object associated with a particular database
909 ** connection. See also [SQLITE_FCNTL_JOURNAL_POINTER].
910 **
911 ** <li>[[SQLITE_FCNTL_JOURNAL_POINTER]]
912 ** The [SQLITE_FCNTL_JOURNAL_POINTER] opcode is used to obtain a pointer
913 ** to the [sqlite3_file] object associated with the journal file (either
914 ** the [rollback journal] or the [write-ahead log]) for a particular database
915 ** connection. See also [SQLITE_FCNTL_FILE_POINTER].
916 **
917 ** <li>[[SQLITE_FCNTL_SYNC_OMITTED]]
918 ** No longer in use.
919 **
920 ** <li>[[SQLITE_FCNTL_SYNC]]
921 ** The [SQLITE_FCNTL_SYNC] opcode is generated internally by SQLite and
922 ** sent to the VFS immediately before the xSync method is invoked on a
923 ** database file descriptor. Or, if the xSync method is not invoked
924 ** because the user has configured SQLite with
925 ** [PRAGMA synchronous | PRAGMA synchronous=OFF] it is invoked in place
926 ** of the xSync method. In most cases, the pointer argument passed with
927 ** this file-control is NULL. However, if the database file is being synced
928 ** as part of a multi-database commit, the argument points to a nul-terminated
929 ** string containing the transactions super-journal file name. VFSes that
930 ** do not need this signal should silently ignore this opcode. Applications
931 ** should not call [sqlite3_file_control()] with this opcode as doing so may
932 ** disrupt the operation of the specialized VFSes that do require it.
933 **
934 ** <li>[[SQLITE_FCNTL_COMMIT_PHASETWO]]
935 ** The [SQLITE_FCNTL_COMMIT_PHASETWO] opcode is generated internally by SQLite
936 ** and sent to the VFS after a transaction has been committed immediately
937 ** but before the database is unlocked. VFSes that do not need this signal
938 ** should silently ignore this opcode. Applications should not call
939 ** [sqlite3_file_control()] with this opcode as doing so may disrupt the
940 ** operation of the specialized VFSes that do require it.
941 **
942 ** <li>[[SQLITE_FCNTL_WIN32_AV_RETRY]]
943 ** ^The [SQLITE_FCNTL_WIN32_AV_RETRY] opcode is used to configure automatic
944 ** retry counts and intervals for certain disk I/O operations for the
945 ** windows [VFS] in order to provide robustness in the presence of
946 ** anti-virus programs. By default, the windows VFS will retry file read,
947 ** file write, and file delete operations up to 10 times, with a delay
948 ** of 25 milliseconds before the first retry and with the delay increasing
949 ** by an additional 25 milliseconds with each subsequent retry. This
950 ** opcode allows these two values (10 retries and 25 milliseconds of delay)
951 ** to be adjusted. The values are changed for all database connections
952 ** within the same process. The argument is a pointer to an array of two
953 ** integers where the first integer is the new retry count and the second
954 ** integer is the delay. If either integer is negative, then the setting
955 ** is not changed but instead the prior value of that setting is written
956 ** into the array entry, allowing the current retry settings to be
957 ** interrogated. The zDbName parameter is ignored.
958 **
959 ** <li>[[SQLITE_FCNTL_PERSIST_WAL]]
960 ** ^The [SQLITE_FCNTL_PERSIST_WAL] opcode is used to set or query the
961 ** persistent [WAL | Write Ahead Log] setting. By default, the auxiliary
962 ** write ahead log ([WAL file]) and shared memory
963 ** files used for transaction control
964 ** are automatically deleted when the latest connection to the database
965 ** closes. Setting persistent WAL mode causes those files to persist after
966 ** close. Persisting the files is useful when other processes that do not
967 ** have write permission on the directory containing the database file want
968 ** to read the database file, as the WAL and shared memory files must exist
969 ** in order for the database to be readable. The fourth parameter to
970 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
971 ** That integer is 0 to disable persistent WAL mode or 1 to enable persistent
972 ** WAL mode. If the integer is -1, then it is overwritten with the current
973 ** WAL persistence setting.
974 **
975 ** <li>[[SQLITE_FCNTL_POWERSAFE_OVERWRITE]]
976 ** ^The [SQLITE_FCNTL_POWERSAFE_OVERWRITE] opcode is used to set or query the
977 ** persistent "powersafe-overwrite" or "PSOW" setting. The PSOW setting
978 ** determines the [SQLITE_IOCAP_POWERSAFE_OVERWRITE] bit of the
979 ** xDeviceCharacteristics methods. The fourth parameter to
980 ** [sqlite3_file_control()] for this opcode should be a pointer to an integer.
981 ** That integer is 0 to disable zero-damage mode or 1 to enable zero-damage
982 ** mode. If the integer is -1, then it is overwritten with the current
983 ** zero-damage mode setting.
984 **
985 ** <li>[[SQLITE_FCNTL_OVERWRITE]]
986 ** ^The [SQLITE_FCNTL_OVERWRITE] opcode is invoked by SQLite after opening
987 ** a write transaction to indicate that, unless it is rolled back for some
988 ** reason, the entire database file will be overwritten by the current
989 ** transaction. This is used by VACUUM operations.
990 **
991 ** <li>[[SQLITE_FCNTL_VFSNAME]]
992 ** ^The [SQLITE_FCNTL_VFSNAME] opcode can be used to obtain the names of
993 ** all [VFSes] in the VFS stack. The names are of all VFS shims and the
994 ** final bottom-level VFS are written into memory obtained from
995 ** [sqlite3_malloc()] and the result is stored in the char* variable
996 ** that the fourth parameter of [sqlite3_file_control()] points to.
997 ** The caller is responsible for freeing the memory when done. As with
998 ** all file-control actions, there is no guarantee that this will actually
999 ** do anything. Callers should initialize the char* variable to a NULL
1000 ** pointer in case this file-control is not implemented. This file-control
1001 ** is intended for diagnostic use only.
1002 **
1003 ** <li>[[SQLITE_FCNTL_VFS_POINTER]]
1004 ** ^The [SQLITE_FCNTL_VFS_POINTER] opcode finds a pointer to the top-level
1005 ** [VFSes] currently in use. ^(The argument X in
1006 ** sqlite3_file_control(db,SQLITE_FCNTL_VFS_POINTER,X) must be
1007 ** of type "[sqlite3_vfs] **". This opcodes will set *X
1008 ** to a pointer to the top-level VFS.)^
1009 ** ^When there are multiple VFS shims in the stack, this opcode finds the
1010 ** upper-most shim only.
1011 **
1012 ** <li>[[SQLITE_FCNTL_PRAGMA]]
1013 ** ^Whenever a [PRAGMA] statement is parsed, an [SQLITE_FCNTL_PRAGMA]
1014 ** file control is sent to the open [sqlite3_file] object corresponding
1015 ** to the database file to which the pragma statement refers. ^The argument
1016 ** to the [SQLITE_FCNTL_PRAGMA] file control is an array of
1017 ** pointers to strings (char**) in which the second element of the array
1018 ** is the name of the pragma and the third element is the argument to the
1019 ** pragma or NULL if the pragma has no argument. ^The handler for an
1020 ** [SQLITE_FCNTL_PRAGMA] file control can optionally make the first element
1021 ** of the char** argument point to a string obtained from [sqlite3_mprintf()]
1022 ** or the equivalent and that string will become the result of the pragma or
1023 ** the error message if the pragma fails. ^If the
1024 ** [SQLITE_FCNTL_PRAGMA] file control returns [SQLITE_NOTFOUND], then normal
1025 ** [PRAGMA] processing continues. ^If the [SQLITE_FCNTL_PRAGMA]
1026 ** file control returns [SQLITE_OK], then the parser assumes that the
1027 ** VFS has handled the PRAGMA itself and the parser generates a no-op
1028 ** prepared statement if result string is NULL, or that returns a copy
1029 ** of the result string if the string is non-NULL.
1030 ** ^If the [SQLITE_FCNTL_PRAGMA] file control returns
1031 ** any result code other than [SQLITE_OK] or [SQLITE_NOTFOUND], that means
1032 ** that the VFS encountered an error while handling the [PRAGMA] and the
1033 ** compilation of the PRAGMA fails with an error. ^The [SQLITE_FCNTL_PRAGMA]
1034 ** file control occurs at the beginning of pragma statement analysis and so
1035 ** it is able to override built-in [PRAGMA] statements.
1036 **
1037 ** <li>[[SQLITE_FCNTL_BUSYHANDLER]]
1038 ** ^The [SQLITE_FCNTL_BUSYHANDLER]
1039 ** file-control may be invoked by SQLite on the database file handle
1040 ** shortly after it is opened in order to provide a custom VFS with access
1041 ** to the connection's busy-handler callback. The argument is of type (void**)
1042 ** - an array of two (void *) values. The first (void *) actually points
1043 ** to a function of type (int (*)(void *)). In order to invoke the connection's
1044 ** busy-handler, this function should be invoked with the second (void *) in
1045 ** the array as the only argument. If it returns non-zero, then the operation
1046 ** should be retried. If it returns zero, the custom VFS should abandon the
1047 ** current operation.
1048 **
1049 ** <li>[[SQLITE_FCNTL_TEMPFILENAME]]
1050 ** ^Applications can invoke the [SQLITE_FCNTL_TEMPFILENAME] file-control
1051 ** to have SQLite generate a
1052 ** temporary filename using the same algorithm that is followed to generate
1053 ** temporary filenames for TEMP tables and other internal uses. The
1054 ** argument should be a char** which will be filled with the filename
1055 ** written into memory obtained from [sqlite3_malloc()]. The caller should
1056 ** invoke [sqlite3_free()] on the result to avoid a memory leak.
1057 **
1058 ** <li>[[SQLITE_FCNTL_MMAP_SIZE]]
1059 ** The [SQLITE_FCNTL_MMAP_SIZE] file control is used to query or set the
1060 ** maximum number of bytes that will be used for memory-mapped I/O.
1061 ** The argument is a pointer to a value of type sqlite3_int64 that
1062 ** is an advisory maximum number of bytes in the file to memory map. The
1063 ** pointer is overwritten with the old value. The limit is not changed if
1064 ** the value originally pointed to is negative, and so the current limit
1065 ** can be queried by passing in a pointer to a negative number. This
1066 ** file-control is used internally to implement [PRAGMA mmap_size].
1067 **
1068 ** <li>[[SQLITE_FCNTL_TRACE]]
1069 ** The [SQLITE_FCNTL_TRACE] file control provides advisory information
1070 ** to the VFS about what the higher layers of the SQLite stack are doing.
1071 ** This file control is used by some VFS activity tracing [shims].
1072 ** The argument is a zero-terminated string. Higher layers in the
1073 ** SQLite stack may generate instances of this file control if
1074 ** the [SQLITE_USE_FCNTL_TRACE] compile-time option is enabled.
1075 **
1076 ** <li>[[SQLITE_FCNTL_HAS_MOVED]]
1077 ** The [SQLITE_FCNTL_HAS_MOVED] file control interprets its argument as a
1078 ** pointer to an integer and it writes a boolean into that integer depending
1079 ** on whether or not the file has been renamed, moved, or deleted since it
1080 ** was first opened.
1081 **
1082 ** <li>[[SQLITE_FCNTL_WIN32_GET_HANDLE]]
1083 ** The [SQLITE_FCNTL_WIN32_GET_HANDLE] opcode can be used to obtain the
1084 ** underlying native file handle associated with a file handle. This file
1085 ** control interprets its argument as a pointer to a native file handle and
1086 ** writes the resulting value there.
1087 **
1088 ** <li>[[SQLITE_FCNTL_WIN32_SET_HANDLE]]
1089 ** The [SQLITE_FCNTL_WIN32_SET_HANDLE] opcode is used for debugging. This
1090 ** opcode causes the xFileControl method to swap the file handle with the one
1091 ** pointed to by the pArg argument. This capability is used during testing
1092 ** and only needs to be supported when SQLITE_TEST is defined.
1093 **
1094 ** <li>[[SQLITE_FCNTL_WAL_BLOCK]]
1095 ** The [SQLITE_FCNTL_WAL_BLOCK] is a signal to the VFS layer that it might
1096 ** be advantageous to block on the next WAL lock if the lock is not immediately
1097 ** available. The WAL subsystem issues this signal during rare
1098 ** circumstances in order to fix a problem with priority inversion.
1099 ** Applications should <em>not</em> use this file-control.
1100 **
1101 ** <li>[[SQLITE_FCNTL_ZIPVFS]]
1102 ** The [SQLITE_FCNTL_ZIPVFS] opcode is implemented by zipvfs only. All other
1103 ** VFS should return SQLITE_NOTFOUND for this opcode.
1104 **
1105 ** <li>[[SQLITE_FCNTL_RBU]]
1106 ** The [SQLITE_FCNTL_RBU] opcode is implemented by the special VFS used by
1107 ** the RBU extension only. All other VFS should return SQLITE_NOTFOUND for
1108 ** this opcode.
1109 **
1110 ** <li>[[SQLITE_FCNTL_BEGIN_ATOMIC_WRITE]]
1111 ** If the [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] opcode returns SQLITE_OK, then
1112 ** the file descriptor is placed in "batch write mode", which
1113 ** means all subsequent write operations will be deferred and done
1114 ** atomically at the next [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]. Systems
1115 ** that do not support batch atomic writes will return SQLITE_NOTFOUND.
1116 ** ^Following a successful SQLITE_FCNTL_BEGIN_ATOMIC_WRITE and prior to
1117 ** the closing [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] or
1118 ** [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE], SQLite will make
1119 ** no VFS interface calls on the same [sqlite3_file] file descriptor
1120 ** except for calls to the xWrite method and the xFileControl method
1121 ** with [SQLITE_FCNTL_SIZE_HINT].
1122 **
1123 ** <li>[[SQLITE_FCNTL_COMMIT_ATOMIC_WRITE]]
1124 ** The [SQLITE_FCNTL_COMMIT_ATOMIC_WRITE] opcode causes all write
1125 ** operations since the previous successful call to
1126 ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be performed atomically.
1127 ** This file control returns [SQLITE_OK] if and only if the writes were
1128 ** all performed successfully and have been committed to persistent storage.
1129 ** ^Regardless of whether or not it is successful, this file control takes
1130 ** the file descriptor out of batch write mode so that all subsequent
1131 ** write operations are independent.
1132 ** ^SQLite will never invoke SQLITE_FCNTL_COMMIT_ATOMIC_WRITE without
1133 ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE].
1134 **
1135 ** <li>[[SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE]]
1136 ** The [SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE] opcode causes all write
1137 ** operations since the previous successful call to
1138 ** [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE] to be rolled back.
1139 ** ^This file control takes the file descriptor out of batch write mode
1140 ** so that all subsequent write operations are independent.
1141 ** ^SQLite will never invoke SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE without
1142 ** a prior successful call to [SQLITE_FCNTL_BEGIN_ATOMIC_WRITE].
1143 **
1144 ** <li>[[SQLITE_FCNTL_LOCK_TIMEOUT]]
1145 ** The [SQLITE_FCNTL_LOCK_TIMEOUT] opcode is used to configure a VFS
1146 ** to block for up to M milliseconds before failing when attempting to
1147 ** obtain a file lock using the xLock or xShmLock methods of the VFS.
1148 ** The parameter is a pointer to a 32-bit signed integer that contains
1149 ** the value that M is to be set to. Before returning, the 32-bit signed
1150 ** integer is overwritten with the previous value of M.
1151 **
1152 ** <li>[[SQLITE_FCNTL_DATA_VERSION]]
1153 ** The [SQLITE_FCNTL_DATA_VERSION] opcode is used to detect changes to
1154 ** a database file. The argument is a pointer to a 32-bit unsigned integer.
1155 ** The "data version" for the pager is written into the pointer. The
1156 ** "data version" changes whenever any change occurs to the corresponding
1157 ** database file, either through SQL statements on the same database
1158 ** connection or through transactions committed by separate database
1159 ** connections possibly in other processes. The [sqlite3_total_changes()]
1160 ** interface can be used to find if any database on the connection has changed,
1161 ** but that interface responds to changes on TEMP as well as MAIN and does
1162 ** not provide a mechanism to detect changes to MAIN only. Also, the
1163 ** [sqlite3_total_changes()] interface responds to internal changes only and
1164 ** omits changes made by other database connections. The
1165 ** [PRAGMA data_version] command provides a mechanism to detect changes to
1166 ** a single attached database that occur due to other database connections,
1167 ** but omits changes implemented by the database connection on which it is
1168 ** called. This file control is the only mechanism to detect changes that
1169 ** happen either internally or externally and that are associated with
1170 ** a particular attached database.
1171 **
1172 ** <li>[[SQLITE_FCNTL_CKPT_START]]
1173 ** The [SQLITE_FCNTL_CKPT_START] opcode is invoked from within a checkpoint
1174 ** in wal mode before the client starts to copy pages from the wal
1175 ** file to the database file.
1176 **
1177 ** <li>[[SQLITE_FCNTL_CKPT_DONE]]
1178 ** The [SQLITE_FCNTL_CKPT_DONE] opcode is invoked from within a checkpoint
1179 ** in wal mode after the client has finished copying pages from the wal
1180 ** file to the database file, but before the *-shm file is updated to
1181 ** record the fact that the pages have been checkpointed.
1182 **
1183 ** <li>[[SQLITE_FCNTL_EXTERNAL_READER]]
1184 ** The EXPERIMENTAL [SQLITE_FCNTL_EXTERNAL_READER] opcode is used to detect
1185 ** whether or not there is a database client in another process with a wal-mode
1186 ** transaction open on the database or not. It is only available on unix.The
1187 ** (void*) argument passed with this file-control should be a pointer to a
1188 ** value of type (int). The integer value is set to 1 if the database is a wal
1189 ** mode database and there exists at least one client in another process that
1190 ** currently has an SQL transaction open on the database. It is set to 0 if
1191 ** the database is not a wal-mode db, or if there is no such connection in any
1192 ** other process. This opcode cannot be used to detect transactions opened
1193 ** by clients within the current process, only within other processes.
1194 **
1195 ** <li>[[SQLITE_FCNTL_CKSM_FILE]]
1196 ** The [SQLITE_FCNTL_CKSM_FILE] opcode is for use internally by the
1197 ** [checksum VFS shim] only.
1198 **
1199 ** <li>[[SQLITE_FCNTL_RESET_CACHE]]
1200 ** If there is currently no transaction open on the database, and the
1201 ** database is not a temp db, then the [SQLITE_FCNTL_RESET_CACHE] file-control
1202 ** purges the contents of the in-memory page cache. If there is an open
1203 ** transaction, or if the db is a temp-db, this opcode is a no-op, not an error.
1204 ** </ul>
1205 */
1206 #define SQLITE_FCNTL_LOCKSTATE 1
1207 #define SQLITE_FCNTL_GET_LOCKPROXYFILE 2
1208 #define SQLITE_FCNTL_SET_LOCKPROXYFILE 3
1209 #define SQLITE_FCNTL_LAST_ERRNO 4
1210 #define SQLITE_FCNTL_SIZE_HINT 5
1211 #define SQLITE_FCNTL_CHUNK_SIZE 6
1212 #define SQLITE_FCNTL_FILE_POINTER 7
1213 #define SQLITE_FCNTL_SYNC_OMITTED 8
1214 #define SQLITE_FCNTL_WIN32_AV_RETRY 9
1215 #define SQLITE_FCNTL_PERSIST_WAL 10
1216 #define SQLITE_FCNTL_OVERWRITE 11
1217 #define SQLITE_FCNTL_VFSNAME 12
1218 #define SQLITE_FCNTL_POWERSAFE_OVERWRITE 13
1219 #define SQLITE_FCNTL_PRAGMA 14
1220 #define SQLITE_FCNTL_BUSYHANDLER 15
1221 #define SQLITE_FCNTL_TEMPFILENAME 16
1222 #define SQLITE_FCNTL_MMAP_SIZE 18
1223 #define SQLITE_FCNTL_TRACE 19
1224 #define SQLITE_FCNTL_HAS_MOVED 20
1225 #define SQLITE_FCNTL_SYNC 21
1226 #define SQLITE_FCNTL_COMMIT_PHASETWO 22
1227 #define SQLITE_FCNTL_WIN32_SET_HANDLE 23
1228 #define SQLITE_FCNTL_WAL_BLOCK 24
1229 #define SQLITE_FCNTL_ZIPVFS 25
1230 #define SQLITE_FCNTL_RBU 26
1231 #define SQLITE_FCNTL_VFS_POINTER 27
1232 #define SQLITE_FCNTL_JOURNAL_POINTER 28
1233 #define SQLITE_FCNTL_WIN32_GET_HANDLE 29
1234 #define SQLITE_FCNTL_PDB 30
1235 #define SQLITE_FCNTL_BEGIN_ATOMIC_WRITE 31
1236 #define SQLITE_FCNTL_COMMIT_ATOMIC_WRITE 32
1237 #define SQLITE_FCNTL_ROLLBACK_ATOMIC_WRITE 33
1238 #define SQLITE_FCNTL_LOCK_TIMEOUT 34
1239 #define SQLITE_FCNTL_DATA_VERSION 35
1240 #define SQLITE_FCNTL_SIZE_LIMIT 36
1241 #define SQLITE_FCNTL_CKPT_DONE 37
1242 #define SQLITE_FCNTL_RESERVE_BYTES 38
1243 #define SQLITE_FCNTL_CKPT_START 39
1244 #define SQLITE_FCNTL_EXTERNAL_READER 40
1245 #define SQLITE_FCNTL_CKSM_FILE 41
1246 #define SQLITE_FCNTL_RESET_CACHE 42
1247
1248 /* deprecated names */
1249 #define SQLITE_GET_LOCKPROXYFILE SQLITE_FCNTL_GET_LOCKPROXYFILE
1250 #define SQLITE_SET_LOCKPROXYFILE SQLITE_FCNTL_SET_LOCKPROXYFILE
1251 #define SQLITE_LAST_ERRNO SQLITE_FCNTL_LAST_ERRNO
1252
1253
1254 /*
1255 ** CAPI3REF: Mutex Handle
1256 **
1257 ** The mutex module within SQLite defines [sqlite3_mutex] to be an
1258 ** abstract type for a mutex object. The SQLite core never looks
1259 ** at the internal representation of an [sqlite3_mutex]. It only
1260 ** deals with pointers to the [sqlite3_mutex] object.
1261 **
1262 ** Mutexes are created using [sqlite3_mutex_alloc()].
1263 */
1264 typedef struct sqlite3_mutex sqlite3_mutex;
1265
1266 /*
1267 ** CAPI3REF: Loadable Extension Thunk
1268 **
1269 ** A pointer to the opaque sqlite3_api_routines structure is passed as
1270 ** the third parameter to entry points of [loadable extensions]. This
1271 ** structure must be typedefed in order to work around compiler warnings
1272 ** on some platforms.
1273 */
1274 typedef struct sqlite3_api_routines sqlite3_api_routines;
1275
1276 /*
1277 ** CAPI3REF: File Name
1278 **
1279 ** Type [sqlite3_filename] is used by SQLite to pass filenames to the
1280 ** xOpen method of a [VFS]. It may be cast to (const char*) and treated
1281 ** as a normal, nul-terminated, UTF-8 buffer containing the filename, but
1282 ** may also be passed to special APIs such as:
1283 **
1284 ** <ul>
1285 ** <li> sqlite3_filename_database()
1286 ** <li> sqlite3_filename_journal()
1287 ** <li> sqlite3_filename_wal()
1288 ** <li> sqlite3_uri_parameter()
1289 ** <li> sqlite3_uri_boolean()
1290 ** <li> sqlite3_uri_int64()
1291 ** <li> sqlite3_uri_key()
1292 ** </ul>
1293 */
1294 typedef const char *sqlite3_filename;
1295
1296 /*
1297 ** CAPI3REF: OS Interface Object
1298 **
1299 ** An instance of the sqlite3_vfs object defines the interface between
1300 ** the SQLite core and the underlying operating system. The "vfs"
1301 ** in the name of the object stands for "virtual file system". See
1302 ** the [VFS | VFS documentation] for further information.
1303 **
1304 ** The VFS interface is sometimes extended by adding new methods onto
1305 ** the end. Each time such an extension occurs, the iVersion field
1306 ** is incremented. The iVersion value started out as 1 in
1307 ** SQLite [version 3.5.0] on [dateof:3.5.0], then increased to 2
1308 ** with SQLite [version 3.7.0] on [dateof:3.7.0], and then increased
1309 ** to 3 with SQLite [version 3.7.6] on [dateof:3.7.6]. Additional fields
1310 ** may be appended to the sqlite3_vfs object and the iVersion value
1311 ** may increase again in future versions of SQLite.
1312 ** Note that due to an oversight, the structure
1313 ** of the sqlite3_vfs object changed in the transition from
1314 ** SQLite [version 3.5.9] to [version 3.6.0] on [dateof:3.6.0]
1315 ** and yet the iVersion field was not increased.
1316 **
1317 ** The szOsFile field is the size of the subclassed [sqlite3_file]
1318 ** structure used by this VFS. mxPathname is the maximum length of
1319 ** a pathname in this VFS.
1320 **
1321 ** Registered sqlite3_vfs objects are kept on a linked list formed by
1322 ** the pNext pointer. The [sqlite3_vfs_register()]
1323 ** and [sqlite3_vfs_unregister()] interfaces manage this list
1324 ** in a thread-safe way. The [sqlite3_vfs_find()] interface
1325 ** searches the list. Neither the application code nor the VFS
1326 ** implementation should use the pNext pointer.
1327 **
1328 ** The pNext field is the only field in the sqlite3_vfs
1329 ** structure that SQLite will ever modify. SQLite will only access
1330 ** or modify this field while holding a particular static mutex.
1331 ** The application should never modify anything within the sqlite3_vfs
1332 ** object once the object has been registered.
1333 **
1334 ** The zName field holds the name of the VFS module. The name must
1335 ** be unique across all VFS modules.
1336 **
1337 ** [[sqlite3_vfs.xOpen]]
1338 ** ^SQLite guarantees that the zFilename parameter to xOpen
1339 ** is either a NULL pointer or string obtained
1340 ** from xFullPathname() with an optional suffix added.
1341 ** ^If a suffix is added to the zFilename parameter, it will
1342 ** consist of a single "-" character followed by no more than
1343 ** 11 alphanumeric and/or "-" characters.
1344 ** ^SQLite further guarantees that
1345 ** the string will be valid and unchanged until xClose() is
1346 ** called. Because of the previous sentence,
1347 ** the [sqlite3_file] can safely store a pointer to the
1348 ** filename if it needs to remember the filename for some reason.
1349 ** If the zFilename parameter to xOpen is a NULL pointer then xOpen
1350 ** must invent its own temporary name for the file. ^Whenever the
1351 ** xFilename parameter is NULL it will also be the case that the
1352 ** flags parameter will include [SQLITE_OPEN_DELETEONCLOSE].
1353 **
1354 ** The flags argument to xOpen() includes all bits set in
1355 ** the flags argument to [sqlite3_open_v2()]. Or if [sqlite3_open()]
1356 ** or [sqlite3_open16()] is used, then flags includes at least
1357 ** [SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE].
1358 ** If xOpen() opens a file read-only then it sets *pOutFlags to
1359 ** include [SQLITE_OPEN_READONLY]. Other bits in *pOutFlags may be set.
1360 **
1361 ** ^(SQLite will also add one of the following flags to the xOpen()
1362 ** call, depending on the object being opened:
1363 **
1364 ** <ul>
1365 ** <li> [SQLITE_OPEN_MAIN_DB]
1366 ** <li> [SQLITE_OPEN_MAIN_JOURNAL]
1367 ** <li> [SQLITE_OPEN_TEMP_DB]
1368 ** <li> [SQLITE_OPEN_TEMP_JOURNAL]
1369 ** <li> [SQLITE_OPEN_TRANSIENT_DB]
1370 ** <li> [SQLITE_OPEN_SUBJOURNAL]
1371 ** <li> [SQLITE_OPEN_SUPER_JOURNAL]
1372 ** <li> [SQLITE_OPEN_WAL]
1373 ** </ul>)^
1374 **
1375 ** The file I/O implementation can use the object type flags to
1376 ** change the way it deals with files. For example, an application
1377 ** that does not care about crash recovery or rollback might make
1378 ** the open of a journal file a no-op. Writes to this journal would
1379 ** also be no-ops, and any attempt to read the journal would return
1380 ** SQLITE_IOERR. Or the implementation might recognize that a database
1381 ** file will be doing page-aligned sector reads and writes in a random
1382 ** order and set up its I/O subsystem accordingly.
1383 **
1384 ** SQLite might also add one of the following flags to the xOpen method:
1385 **
1386 ** <ul>
1387 ** <li> [SQLITE_OPEN_DELETEONCLOSE]
1388 ** <li> [SQLITE_OPEN_EXCLUSIVE]
1389 ** </ul>
1390 **
1391 ** The [SQLITE_OPEN_DELETEONCLOSE] flag means the file should be
1392 ** deleted when it is closed. ^The [SQLITE_OPEN_DELETEONCLOSE]
1393 ** will be set for TEMP databases and their journals, transient
1394 ** databases, and subjournals.
1395 **
1396 ** ^The [SQLITE_OPEN_EXCLUSIVE] flag is always used in conjunction
1397 ** with the [SQLITE_OPEN_CREATE] flag, which are both directly
1398 ** analogous to the O_EXCL and O_CREAT flags of the POSIX open()
1399 ** API. The SQLITE_OPEN_EXCLUSIVE flag, when paired with the
1400 ** SQLITE_OPEN_CREATE, is used to indicate that file should always
1401 ** be created, and that it is an error if it already exists.
1402 ** It is <i>not</i> used to indicate the file should be opened
1403 ** for exclusive access.
1404 **
1405 ** ^At least szOsFile bytes of memory are allocated by SQLite
1406 ** to hold the [sqlite3_file] structure passed as the third
1407 ** argument to xOpen. The xOpen method does not have to
1408 ** allocate the structure; it should just fill it in. Note that
1409 ** the xOpen method must set the sqlite3_file.pMethods to either
1410 ** a valid [sqlite3_io_methods] object or to NULL. xOpen must do
1411 ** this even if the open fails. SQLite expects that the sqlite3_file.pMethods
1412 ** element will be valid after xOpen returns regardless of the success
1413 ** or failure of the xOpen call.
1414 **
1415 ** [[sqlite3_vfs.xAccess]]
1416 ** ^The flags argument to xAccess() may be [SQLITE_ACCESS_EXISTS]
1417 ** to test for the existence of a file, or [SQLITE_ACCESS_READWRITE] to
1418 ** test whether a file is readable and writable, or [SQLITE_ACCESS_READ]
1419 ** to test whether a file is at least readable. The SQLITE_ACCESS_READ
1420 ** flag is never actually used and is not implemented in the built-in
1421 ** VFSes of SQLite. The file is named by the second argument and can be a
1422 ** directory. The xAccess method returns [SQLITE_OK] on success or some
1423 ** non-zero error code if there is an I/O error or if the name of
1424 ** the file given in the second argument is illegal. If SQLITE_OK
1425 ** is returned, then non-zero or zero is written into *pResOut to indicate
1426 ** whether or not the file is accessible.
1427 **
1428 ** ^SQLite will always allocate at least mxPathname+1 bytes for the
1429 ** output buffer xFullPathname. The exact size of the output buffer
1430 ** is also passed as a parameter to both methods. If the output buffer
1431 ** is not large enough, [SQLITE_CANTOPEN] should be returned. Since this is
1432 ** handled as a fatal error by SQLite, vfs implementations should endeavor
1433 ** to prevent this by setting mxPathname to a sufficiently large value.
1434 **
1435 ** The xRandomness(), xSleep(), xCurrentTime(), and xCurrentTimeInt64()
1436 ** interfaces are not strictly a part of the filesystem, but they are
1437 ** included in the VFS structure for completeness.
1438 ** The xRandomness() function attempts to return nBytes bytes
1439 ** of good-quality randomness into zOut. The return value is
1440 ** the actual number of bytes of randomness obtained.
1441 ** The xSleep() method causes the calling thread to sleep for at
1442 ** least the number of microseconds given. ^The xCurrentTime()
1443 ** method returns a Julian Day Number for the current date and time as
1444 ** a floating point value.
1445 ** ^The xCurrentTimeInt64() method returns, as an integer, the Julian
1446 ** Day Number multiplied by 86400000 (the number of milliseconds in
1447 ** a 24-hour day).
1448 ** ^SQLite will use the xCurrentTimeInt64() method to get the current
1449 ** date and time if that method is available (if iVersion is 2 or
1450 ** greater and the function pointer is not NULL) and will fall back
1451 ** to xCurrentTime() if xCurrentTimeInt64() is unavailable.
1452 **
1453 ** ^The xSetSystemCall(), xGetSystemCall(), and xNestSystemCall() interfaces
1454 ** are not used by the SQLite core. These optional interfaces are provided
1455 ** by some VFSes to facilitate testing of the VFS code. By overriding
1456 ** system calls with functions under its control, a test program can
1457 ** simulate faults and error conditions that would otherwise be difficult
1458 ** or impossible to induce. The set of system calls that can be overridden
1459 ** varies from one VFS to another, and from one version of the same VFS to the
1460 ** next. Applications that use these interfaces must be prepared for any
1461 ** or all of these interfaces to be NULL or for their behavior to change
1462 ** from one release to the next. Applications must not attempt to access
1463 ** any of these methods if the iVersion of the VFS is less than 3.
1464 */
1465 typedef struct sqlite3_vfs sqlite3_vfs;
1466 typedef void (*sqlite3_syscall_ptr)(void);
1467 struct sqlite3_vfs {
1468 int iVersion; /* Structure version number (currently 3) */
1469 int szOsFile; /* Size of subclassed sqlite3_file */
1470 int mxPathname; /* Maximum file pathname length */
1471 sqlite3_vfs *pNext; /* Next registered VFS */
1472 const char *zName; /* Name of this virtual file system */
1473 void *pAppData; /* Pointer to application-specific data */
1474 int (*xOpen)(sqlite3_vfs*, sqlite3_filename zName, sqlite3_file*,
1475 int flags, int *pOutFlags);
1476 int (*xDelete)(sqlite3_vfs*, const char *zName, int syncDir);
1477 int (*xAccess)(sqlite3_vfs*, const char *zName, int flags, int *pResOut);
1478 int (*xFullPathname)(sqlite3_vfs*, const char *zName, int nOut, char *zOut);
1479 void *(*xDlOpen)(sqlite3_vfs*, const char *zFilename);
1480 void (*xDlError)(sqlite3_vfs*, int nByte, char *zErrMsg);
1481 void (*(*xDlSym)(sqlite3_vfs*,void*, const char *zSymbol))(void);
1482 void (*xDlClose)(sqlite3_vfs*, void*);
1483 int (*xRandomness)(sqlite3_vfs*, int nByte, char *zOut);
1484 int (*xSleep)(sqlite3_vfs*, int microseconds);
1485 int (*xCurrentTime)(sqlite3_vfs*, double*);
1486 int (*xGetLastError)(sqlite3_vfs*, int, char *);
1487 /*
1488 ** The methods above are in version 1 of the sqlite_vfs object
1489 ** definition. Those that follow are added in version 2 or later
1490 */
1491 int (*xCurrentTimeInt64)(sqlite3_vfs*, sqlite3_int64*);
1492 /*
1493 ** The methods above are in versions 1 and 2 of the sqlite_vfs object.
1494 ** Those below are for version 3 and greater.
1495 */
1496 int (*xSetSystemCall)(sqlite3_vfs*, const char *zName, sqlite3_syscall_ptr);
1497 sqlite3_syscall_ptr (*xGetSystemCall)(sqlite3_vfs*, const char *zName);
1498 const char *(*xNextSystemCall)(sqlite3_vfs*, const char *zName);
1499 /*
1500 ** The methods above are in versions 1 through 3 of the sqlite_vfs object.
1501 ** New fields may be appended in future versions. The iVersion
1502 ** value will increment whenever this happens.
1503 */
1504 };
1505
1506 /*
1507 ** CAPI3REF: Flags for the xAccess VFS method
1508 **
1509 ** These integer constants can be used as the third parameter to
1510 ** the xAccess method of an [sqlite3_vfs] object. They determine
1511 ** what kind of permissions the xAccess method is looking for.
1512 ** With SQLITE_ACCESS_EXISTS, the xAccess method
1513 ** simply checks whether the file exists.
1514 ** With SQLITE_ACCESS_READWRITE, the xAccess method
1515 ** checks whether the named directory is both readable and writable
1516 ** (in other words, if files can be added, removed, and renamed within
1517 ** the directory).
1518 ** The SQLITE_ACCESS_READWRITE constant is currently used only by the
1519 ** [temp_store_directory pragma], though this could change in a future
1520 ** release of SQLite.
1521 ** With SQLITE_ACCESS_READ, the xAccess method
1522 ** checks whether the file is readable. The SQLITE_ACCESS_READ constant is
1523 ** currently unused, though it might be used in a future release of
1524 ** SQLite.
1525 */
1526 #define SQLITE_ACCESS_EXISTS 0
1527 #define SQLITE_ACCESS_READWRITE 1 /* Used by PRAGMA temp_store_directory */
1528 #define SQLITE_ACCESS_READ 2 /* Unused */
1529
1530 /*
1531 ** CAPI3REF: Flags for the xShmLock VFS method
1532 **
1533 ** These integer constants define the various locking operations
1534 ** allowed by the xShmLock method of [sqlite3_io_methods]. The
1535 ** following are the only legal combinations of flags to the
1536 ** xShmLock method:
1537 **
1538 ** <ul>
1539 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_SHARED
1540 ** <li> SQLITE_SHM_LOCK | SQLITE_SHM_EXCLUSIVE
1541 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_SHARED
1542 ** <li> SQLITE_SHM_UNLOCK | SQLITE_SHM_EXCLUSIVE
1543 ** </ul>
1544 **
1545 ** When unlocking, the same SHARED or EXCLUSIVE flag must be supplied as
1546 ** was given on the corresponding lock.
1547 **
1548 ** The xShmLock method can transition between unlocked and SHARED or
1549 ** between unlocked and EXCLUSIVE. It cannot transition between SHARED
1550 ** and EXCLUSIVE.
1551 */
1552 #define SQLITE_SHM_UNLOCK 1
1553 #define SQLITE_SHM_LOCK 2
1554 #define SQLITE_SHM_SHARED 4
1555 #define SQLITE_SHM_EXCLUSIVE 8
1556
1557 /*
1558 ** CAPI3REF: Maximum xShmLock index
1559 **
1560 ** The xShmLock method on [sqlite3_io_methods] may use values
1561 ** between 0 and this upper bound as its "offset" argument.
1562 ** The SQLite core will never attempt to acquire or release a
1563 ** lock outside of this range
1564 */
1565 #define SQLITE_SHM_NLOCK 8
1566
1567
1568 /*
1569 ** CAPI3REF: Initialize The SQLite Library
1570 **
1571 ** ^The sqlite3_initialize() routine initializes the
1572 ** SQLite library. ^The sqlite3_shutdown() routine
1573 ** deallocates any resources that were allocated by sqlite3_initialize().
1574 ** These routines are designed to aid in process initialization and
1575 ** shutdown on embedded systems. Workstation applications using
1576 ** SQLite normally do not need to invoke either of these routines.
1577 **
1578 ** A call to sqlite3_initialize() is an "effective" call if it is
1579 ** the first time sqlite3_initialize() is invoked during the lifetime of
1580 ** the process, or if it is the first time sqlite3_initialize() is invoked
1581 ** following a call to sqlite3_shutdown(). ^(Only an effective call
1582 ** of sqlite3_initialize() does any initialization. All other calls
1583 ** are harmless no-ops.)^
1584 **
1585 ** A call to sqlite3_shutdown() is an "effective" call if it is the first
1586 ** call to sqlite3_shutdown() since the last sqlite3_initialize(). ^(Only
1587 ** an effective call to sqlite3_shutdown() does any deinitialization.
1588 ** All other valid calls to sqlite3_shutdown() are harmless no-ops.)^
1589 **
1590 ** The sqlite3_initialize() interface is threadsafe, but sqlite3_shutdown()
1591 ** is not. The sqlite3_shutdown() interface must only be called from a
1592 ** single thread. All open [database connections] must be closed and all
1593 ** other SQLite resources must be deallocated prior to invoking
1594 ** sqlite3_shutdown().
1595 **
1596 ** Among other things, ^sqlite3_initialize() will invoke
1597 ** sqlite3_os_init(). Similarly, ^sqlite3_shutdown()
1598 ** will invoke sqlite3_os_end().
1599 **
1600 ** ^The sqlite3_initialize() routine returns [SQLITE_OK] on success.
1601 ** ^If for some reason, sqlite3_initialize() is unable to initialize
1602 ** the library (perhaps it is unable to allocate a needed resource such
1603 ** as a mutex) it returns an [error code] other than [SQLITE_OK].
1604 **
1605 ** ^The sqlite3_initialize() routine is called internally by many other
1606 ** SQLite interfaces so that an application usually does not need to
1607 ** invoke sqlite3_initialize() directly. For example, [sqlite3_open()]
1608 ** calls sqlite3_initialize() so the SQLite library will be automatically
1609 ** initialized when [sqlite3_open()] is called if it has not be initialized
1610 ** already. ^However, if SQLite is compiled with the [SQLITE_OMIT_AUTOINIT]
1611 ** compile-time option, then the automatic calls to sqlite3_initialize()
1612 ** are omitted and the application must call sqlite3_initialize() directly
1613 ** prior to using any other SQLite interface. For maximum portability,
1614 ** it is recommended that applications always invoke sqlite3_initialize()
1615 ** directly prior to using any other SQLite interface. Future releases
1616 ** of SQLite may require this. In other words, the behavior exhibited
1617 ** when SQLite is compiled with [SQLITE_OMIT_AUTOINIT] might become the
1618 ** default behavior in some future release of SQLite.
1619 **
1620 ** The sqlite3_os_init() routine does operating-system specific
1621 ** initialization of the SQLite library. The sqlite3_os_end()
1622 ** routine undoes the effect of sqlite3_os_init(). Typical tasks
1623 ** performed by these routines include allocation or deallocation
1624 ** of static resources, initialization of global variables,
1625 ** setting up a default [sqlite3_vfs] module, or setting up
1626 ** a default configuration using [sqlite3_config()].
1627 **
1628 ** The application should never invoke either sqlite3_os_init()
1629 ** or sqlite3_os_end() directly. The application should only invoke
1630 ** sqlite3_initialize() and sqlite3_shutdown(). The sqlite3_os_init()
1631 ** interface is called automatically by sqlite3_initialize() and
1632 ** sqlite3_os_end() is called by sqlite3_shutdown(). Appropriate
1633 ** implementations for sqlite3_os_init() and sqlite3_os_end()
1634 ** are built into SQLite when it is compiled for Unix, Windows, or OS/2.
1635 ** When [custom builds | built for other platforms]
1636 ** (using the [SQLITE_OS_OTHER=1] compile-time
1637 ** option) the application must supply a suitable implementation for
1638 ** sqlite3_os_init() and sqlite3_os_end(). An application-supplied
1639 ** implementation of sqlite3_os_init() or sqlite3_os_end()
1640 ** must return [SQLITE_OK] on success and some other [error code] upon
1641 ** failure.
1642 */
1643 SQLITE_API int sqlite3_initialize(void);
1644 SQLITE_API int sqlite3_shutdown(void);
1645 SQLITE_API int sqlite3_os_init(void);
1646 SQLITE_API int sqlite3_os_end(void);
1647
1648 /*
1649 ** CAPI3REF: Configuring The SQLite Library
1650 **
1651 ** The sqlite3_config() interface is used to make global configuration
1652 ** changes to SQLite in order to tune SQLite to the specific needs of
1653 ** the application. The default configuration is recommended for most
1654 ** applications and so this routine is usually not necessary. It is
1655 ** provided to support rare applications with unusual needs.
1656 **
1657 ** <b>The sqlite3_config() interface is not threadsafe. The application
1658 ** must ensure that no other SQLite interfaces are invoked by other
1659 ** threads while sqlite3_config() is running.</b>
1660 **
1661 ** The first argument to sqlite3_config() is an integer
1662 ** [configuration option] that determines
1663 ** what property of SQLite is to be configured. Subsequent arguments
1664 ** vary depending on the [configuration option]
1665 ** in the first argument.
1666 **
1667 ** For most configuration options, the sqlite3_config() interface
1668 ** may only be invoked prior to library initialization using
1669 ** [sqlite3_initialize()] or after shutdown by [sqlite3_shutdown()].
1670 ** The exceptional configuration options that may be invoked at any time
1671 ** are called "anytime configuration options".
1672 ** ^If sqlite3_config() is called after [sqlite3_initialize()] and before
1673 ** [sqlite3_shutdown()] with a first argument that is not an anytime
1674 ** configuration option, then the sqlite3_config() call will return SQLITE_MISUSE.
1675 ** Note, however, that ^sqlite3_config() can be called as part of the
1676 ** implementation of an application-defined [sqlite3_os_init()].
1677 **
1678 ** ^When a configuration option is set, sqlite3_config() returns [SQLITE_OK].
1679 ** ^If the option is unknown or SQLite is unable to set the option
1680 ** then this routine returns a non-zero [error code].
1681 */
1682 SQLITE_API int sqlite3_config(int, ...);
1683
1684 /*
1685 ** CAPI3REF: Configure database connections
1686 ** METHOD: sqlite3
1687 **
1688 ** The sqlite3_db_config() interface is used to make configuration
1689 ** changes to a [database connection]. The interface is similar to
1690 ** [sqlite3_config()] except that the changes apply to a single
1691 ** [database connection] (specified in the first argument).
1692 **
1693 ** The second argument to sqlite3_db_config(D,V,...) is the
1694 ** [SQLITE_DBCONFIG_LOOKASIDE | configuration verb] - an integer code
1695 ** that indicates what aspect of the [database connection] is being configured.
1696 ** Subsequent arguments vary depending on the configuration verb.
1697 **
1698 ** ^Calls to sqlite3_db_config() return SQLITE_OK if and only if
1699 ** the call is considered successful.
1700 */
1701 SQLITE_API int sqlite3_db_config(sqlite3*, int op, ...);
1702
1703 /*
1704 ** CAPI3REF: Memory Allocation Routines
1705 **
1706 ** An instance of this object defines the interface between SQLite
1707 ** and low-level memory allocation routines.
1708 **
1709 ** This object is used in only one place in the SQLite interface.
1710 ** A pointer to an instance of this object is the argument to
1711 ** [sqlite3_config()] when the configuration option is
1712 ** [SQLITE_CONFIG_MALLOC] or [SQLITE_CONFIG_GETMALLOC].
1713 ** By creating an instance of this object
1714 ** and passing it to [sqlite3_config]([SQLITE_CONFIG_MALLOC])
1715 ** during configuration, an application can specify an alternative
1716 ** memory allocation subsystem for SQLite to use for all of its
1717 ** dynamic memory needs.
1718 **
1719 ** Note that SQLite comes with several [built-in memory allocators]
1720 ** that are perfectly adequate for the overwhelming majority of applications
1721 ** and that this object is only useful to a tiny minority of applications
1722 ** with specialized memory allocation requirements. This object is
1723 ** also used during testing of SQLite in order to specify an alternative
1724 ** memory allocator that simulates memory out-of-memory conditions in
1725 ** order to verify that SQLite recovers gracefully from such
1726 ** conditions.
1727 **
1728 ** The xMalloc, xRealloc, and xFree methods must work like the
1729 ** malloc(), realloc() and free() functions from the standard C library.
1730 ** ^SQLite guarantees that the second argument to
1731 ** xRealloc is always a value returned by a prior call to xRoundup.
1732 **
1733 ** xSize should return the allocated size of a memory allocation
1734 ** previously obtained from xMalloc or xRealloc. The allocated size
1735 ** is always at least as big as the requested size but may be larger.
1736 **
1737 ** The xRoundup method returns what would be the allocated size of
1738 ** a memory allocation given a particular requested size. Most memory
1739 ** allocators round up memory allocations at least to the next multiple
1740 ** of 8. Some allocators round up to a larger multiple or to a power of 2.
1741 ** Every memory allocation request coming in through [sqlite3_malloc()]
1742 ** or [sqlite3_realloc()] first calls xRoundup. If xRoundup returns 0,
1743 ** that causes the corresponding memory allocation to fail.
1744 **
1745 ** The xInit method initializes the memory allocator. For example,
1746 ** it might allocate any required mutexes or initialize internal data
1747 ** structures. The xShutdown method is invoked (indirectly) by
1748 ** [sqlite3_shutdown()] and should deallocate any resources acquired
1749 ** by xInit. The pAppData pointer is used as the only parameter to
1750 ** xInit and xShutdown.
1751 **
1752 ** SQLite holds the [SQLITE_MUTEX_STATIC_MAIN] mutex when it invokes
1753 ** the xInit method, so the xInit method need not be threadsafe. The
1754 ** xShutdown method is only called from [sqlite3_shutdown()] so it does
1755 ** not need to be threadsafe either. For all other methods, SQLite
1756 ** holds the [SQLITE_MUTEX_STATIC_MEM] mutex as long as the
1757 ** [SQLITE_CONFIG_MEMSTATUS] configuration option is turned on (which
1758 ** it is by default) and so the methods are automatically serialized.
1759 ** However, if [SQLITE_CONFIG_MEMSTATUS] is disabled, then the other
1760 ** methods must be threadsafe or else make their own arrangements for
1761 ** serialization.
1762 **
1763 ** SQLite will never invoke xInit() more than once without an intervening
1764 ** call to xShutdown().
1765 */
1766 typedef struct sqlite3_mem_methods sqlite3_mem_methods;
1767 struct sqlite3_mem_methods {
1768 void *(*xMalloc)(int); /* Memory allocation function */
1769 void (*xFree)(void*); /* Free a prior allocation */
1770 void *(*xRealloc)(void*,int); /* Resize an allocation */
1771 int (*xSize)(void*); /* Return the size of an allocation */
1772 int (*xRoundup)(int); /* Round up request size to allocation size */
1773 int (*xInit)(void*); /* Initialize the memory allocator */
1774 void (*xShutdown)(void*); /* Deinitialize the memory allocator */
1775 void *pAppData; /* Argument to xInit() and xShutdown() */
1776 };
1777
1778 /*
1779 ** CAPI3REF: Configuration Options
1780 ** KEYWORDS: {configuration option}
1781 **
1782 ** These constants are the available integer configuration options that
1783 ** can be passed as the first argument to the [sqlite3_config()] interface.
1784 **
1785 ** Most of the configuration options for sqlite3_config()
1786 ** will only work if invoked prior to [sqlite3_initialize()] or after
1787 ** [sqlite3_shutdown()]. The few exceptions to this rule are called
1788 ** "anytime configuration options".
1789 ** ^Calling [sqlite3_config()] with a first argument that is not an
1790 ** anytime configuration option in between calls to [sqlite3_initialize()] and
1791 ** [sqlite3_shutdown()] is a no-op that returns SQLITE_MISUSE.
1792 **
1793 ** The set of anytime configuration options can change (by insertions
1794 ** and/or deletions) from one release of SQLite to the next.
1795 ** As of SQLite version 3.42.0, the complete set of anytime configuration
1796 ** options is:
1797 ** <ul>
1798 ** <li> SQLITE_CONFIG_LOG
1799 ** <li> SQLITE_CONFIG_PCACHE_HDRSZ
1800 ** </ul>
1801 **
1802 ** New configuration options may be added in future releases of SQLite.
1803 ** Existing configuration options might be discontinued. Applications
1804 ** should check the return code from [sqlite3_config()] to make sure that
1805 ** the call worked. The [sqlite3_config()] interface will return a
1806 ** non-zero [error code] if a discontinued or unsupported configuration option
1807 ** is invoked.
1808 **
1809 ** <dl>
1810 ** [[SQLITE_CONFIG_SINGLETHREAD]] <dt>SQLITE_CONFIG_SINGLETHREAD</dt>
1811 ** <dd>There are no arguments to this option. ^This option sets the
1812 ** [threading mode] to Single-thread. In other words, it disables
1813 ** all mutexing and puts SQLite into a mode where it can only be used
1814 ** by a single thread. ^If SQLite is compiled with
1815 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1816 ** it is not possible to change the [threading mode] from its default
1817 ** value of Single-thread and so [sqlite3_config()] will return
1818 ** [SQLITE_ERROR] if called with the SQLITE_CONFIG_SINGLETHREAD
1819 ** configuration option.</dd>
1820 **
1821 ** [[SQLITE_CONFIG_MULTITHREAD]] <dt>SQLITE_CONFIG_MULTITHREAD</dt>
1822 ** <dd>There are no arguments to this option. ^This option sets the
1823 ** [threading mode] to Multi-thread. In other words, it disables
1824 ** mutexing on [database connection] and [prepared statement] objects.
1825 ** The application is responsible for serializing access to
1826 ** [database connections] and [prepared statements]. But other mutexes
1827 ** are enabled so that SQLite will be safe to use in a multi-threaded
1828 ** environment as long as no two threads attempt to use the same
1829 ** [database connection] at the same time. ^If SQLite is compiled with
1830 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1831 ** it is not possible to set the Multi-thread [threading mode] and
1832 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1833 ** SQLITE_CONFIG_MULTITHREAD configuration option.</dd>
1834 **
1835 ** [[SQLITE_CONFIG_SERIALIZED]] <dt>SQLITE_CONFIG_SERIALIZED</dt>
1836 ** <dd>There are no arguments to this option. ^This option sets the
1837 ** [threading mode] to Serialized. In other words, this option enables
1838 ** all mutexes including the recursive
1839 ** mutexes on [database connection] and [prepared statement] objects.
1840 ** In this mode (which is the default when SQLite is compiled with
1841 ** [SQLITE_THREADSAFE=1]) the SQLite library will itself serialize access
1842 ** to [database connections] and [prepared statements] so that the
1843 ** application is free to use the same [database connection] or the
1844 ** same [prepared statement] in different threads at the same time.
1845 ** ^If SQLite is compiled with
1846 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1847 ** it is not possible to set the Serialized [threading mode] and
1848 ** [sqlite3_config()] will return [SQLITE_ERROR] if called with the
1849 ** SQLITE_CONFIG_SERIALIZED configuration option.</dd>
1850 **
1851 ** [[SQLITE_CONFIG_MALLOC]] <dt>SQLITE_CONFIG_MALLOC</dt>
1852 ** <dd> ^(The SQLITE_CONFIG_MALLOC option takes a single argument which is
1853 ** a pointer to an instance of the [sqlite3_mem_methods] structure.
1854 ** The argument specifies
1855 ** alternative low-level memory allocation routines to be used in place of
1856 ** the memory allocation routines built into SQLite.)^ ^SQLite makes
1857 ** its own private copy of the content of the [sqlite3_mem_methods] structure
1858 ** before the [sqlite3_config()] call returns.</dd>
1859 **
1860 ** [[SQLITE_CONFIG_GETMALLOC]] <dt>SQLITE_CONFIG_GETMALLOC</dt>
1861 ** <dd> ^(The SQLITE_CONFIG_GETMALLOC option takes a single argument which
1862 ** is a pointer to an instance of the [sqlite3_mem_methods] structure.
1863 ** The [sqlite3_mem_methods]
1864 ** structure is filled with the currently defined memory allocation routines.)^
1865 ** This option can be used to overload the default memory allocation
1866 ** routines with a wrapper that simulations memory allocation failure or
1867 ** tracks memory usage, for example. </dd>
1868 **
1869 ** [[SQLITE_CONFIG_SMALL_MALLOC]] <dt>SQLITE_CONFIG_SMALL_MALLOC</dt>
1870 ** <dd> ^The SQLITE_CONFIG_SMALL_MALLOC option takes single argument of
1871 ** type int, interpreted as a boolean, which if true provides a hint to
1872 ** SQLite that it should avoid large memory allocations if possible.
1873 ** SQLite will run faster if it is free to make large memory allocations,
1874 ** but some application might prefer to run slower in exchange for
1875 ** guarantees about memory fragmentation that are possible if large
1876 ** allocations are avoided. This hint is normally off.
1877 ** </dd>
1878 **
1879 ** [[SQLITE_CONFIG_MEMSTATUS]] <dt>SQLITE_CONFIG_MEMSTATUS</dt>
1880 ** <dd> ^The SQLITE_CONFIG_MEMSTATUS option takes single argument of type int,
1881 ** interpreted as a boolean, which enables or disables the collection of
1882 ** memory allocation statistics. ^(When memory allocation statistics are
1883 ** disabled, the following SQLite interfaces become non-operational:
1884 ** <ul>
1885 ** <li> [sqlite3_hard_heap_limit64()]
1886 ** <li> [sqlite3_memory_used()]
1887 ** <li> [sqlite3_memory_highwater()]
1888 ** <li> [sqlite3_soft_heap_limit64()]
1889 ** <li> [sqlite3_status64()]
1890 ** </ul>)^
1891 ** ^Memory allocation statistics are enabled by default unless SQLite is
1892 ** compiled with [SQLITE_DEFAULT_MEMSTATUS]=0 in which case memory
1893 ** allocation statistics are disabled by default.
1894 ** </dd>
1895 **
1896 ** [[SQLITE_CONFIG_SCRATCH]] <dt>SQLITE_CONFIG_SCRATCH</dt>
1897 ** <dd> The SQLITE_CONFIG_SCRATCH option is no longer used.
1898 ** </dd>
1899 **
1900 ** [[SQLITE_CONFIG_PAGECACHE]] <dt>SQLITE_CONFIG_PAGECACHE</dt>
1901 ** <dd> ^The SQLITE_CONFIG_PAGECACHE option specifies a memory pool
1902 ** that SQLite can use for the database page cache with the default page
1903 ** cache implementation.
1904 ** This configuration option is a no-op if an application-defined page
1905 ** cache implementation is loaded using the [SQLITE_CONFIG_PCACHE2].
1906 ** ^There are three arguments to SQLITE_CONFIG_PAGECACHE: A pointer to
1907 ** 8-byte aligned memory (pMem), the size of each page cache line (sz),
1908 ** and the number of cache lines (N).
1909 ** The sz argument should be the size of the largest database page
1910 ** (a power of two between 512 and 65536) plus some extra bytes for each
1911 ** page header. ^The number of extra bytes needed by the page header
1912 ** can be determined using [SQLITE_CONFIG_PCACHE_HDRSZ].
1913 ** ^It is harmless, apart from the wasted memory,
1914 ** for the sz parameter to be larger than necessary. The pMem
1915 ** argument must be either a NULL pointer or a pointer to an 8-byte
1916 ** aligned block of memory of at least sz*N bytes, otherwise
1917 ** subsequent behavior is undefined.
1918 ** ^When pMem is not NULL, SQLite will strive to use the memory provided
1919 ** to satisfy page cache needs, falling back to [sqlite3_malloc()] if
1920 ** a page cache line is larger than sz bytes or if all of the pMem buffer
1921 ** is exhausted.
1922 ** ^If pMem is NULL and N is non-zero, then each database connection
1923 ** does an initial bulk allocation for page cache memory
1924 ** from [sqlite3_malloc()] sufficient for N cache lines if N is positive or
1925 ** of -1024*N bytes if N is negative, . ^If additional
1926 ** page cache memory is needed beyond what is provided by the initial
1927 ** allocation, then SQLite goes to [sqlite3_malloc()] separately for each
1928 ** additional cache line. </dd>
1929 **
1930 ** [[SQLITE_CONFIG_HEAP]] <dt>SQLITE_CONFIG_HEAP</dt>
1931 ** <dd> ^The SQLITE_CONFIG_HEAP option specifies a static memory buffer
1932 ** that SQLite will use for all of its dynamic memory allocation needs
1933 ** beyond those provided for by [SQLITE_CONFIG_PAGECACHE].
1934 ** ^The SQLITE_CONFIG_HEAP option is only available if SQLite is compiled
1935 ** with either [SQLITE_ENABLE_MEMSYS3] or [SQLITE_ENABLE_MEMSYS5] and returns
1936 ** [SQLITE_ERROR] if invoked otherwise.
1937 ** ^There are three arguments to SQLITE_CONFIG_HEAP:
1938 ** An 8-byte aligned pointer to the memory,
1939 ** the number of bytes in the memory buffer, and the minimum allocation size.
1940 ** ^If the first pointer (the memory pointer) is NULL, then SQLite reverts
1941 ** to using its default memory allocator (the system malloc() implementation),
1942 ** undoing any prior invocation of [SQLITE_CONFIG_MALLOC]. ^If the
1943 ** memory pointer is not NULL then the alternative memory
1944 ** allocator is engaged to handle all of SQLites memory allocation needs.
1945 ** The first pointer (the memory pointer) must be aligned to an 8-byte
1946 ** boundary or subsequent behavior of SQLite will be undefined.
1947 ** The minimum allocation size is capped at 2**12. Reasonable values
1948 ** for the minimum allocation size are 2**5 through 2**8.</dd>
1949 **
1950 ** [[SQLITE_CONFIG_MUTEX]] <dt>SQLITE_CONFIG_MUTEX</dt>
1951 ** <dd> ^(The SQLITE_CONFIG_MUTEX option takes a single argument which is a
1952 ** pointer to an instance of the [sqlite3_mutex_methods] structure.
1953 ** The argument specifies alternative low-level mutex routines to be used
1954 ** in place the mutex routines built into SQLite.)^ ^SQLite makes a copy of
1955 ** the content of the [sqlite3_mutex_methods] structure before the call to
1956 ** [sqlite3_config()] returns. ^If SQLite is compiled with
1957 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1958 ** the entire mutexing subsystem is omitted from the build and hence calls to
1959 ** [sqlite3_config()] with the SQLITE_CONFIG_MUTEX configuration option will
1960 ** return [SQLITE_ERROR].</dd>
1961 **
1962 ** [[SQLITE_CONFIG_GETMUTEX]] <dt>SQLITE_CONFIG_GETMUTEX</dt>
1963 ** <dd> ^(The SQLITE_CONFIG_GETMUTEX option takes a single argument which
1964 ** is a pointer to an instance of the [sqlite3_mutex_methods] structure. The
1965 ** [sqlite3_mutex_methods]
1966 ** structure is filled with the currently defined mutex routines.)^
1967 ** This option can be used to overload the default mutex allocation
1968 ** routines with a wrapper used to track mutex usage for performance
1969 ** profiling or testing, for example. ^If SQLite is compiled with
1970 ** the [SQLITE_THREADSAFE | SQLITE_THREADSAFE=0] compile-time option then
1971 ** the entire mutexing subsystem is omitted from the build and hence calls to
1972 ** [sqlite3_config()] with the SQLITE_CONFIG_GETMUTEX configuration option will
1973 ** return [SQLITE_ERROR].</dd>
1974 **
1975 ** [[SQLITE_CONFIG_LOOKASIDE]] <dt>SQLITE_CONFIG_LOOKASIDE</dt>
1976 ** <dd> ^(The SQLITE_CONFIG_LOOKASIDE option takes two arguments that determine
1977 ** the default size of lookaside memory on each [database connection].
1978 ** The first argument is the
1979 ** size of each lookaside buffer slot and the second is the number of
1980 ** slots allocated to each database connection.)^ ^(SQLITE_CONFIG_LOOKASIDE
1981 ** sets the <i>default</i> lookaside size. The [SQLITE_DBCONFIG_LOOKASIDE]
1982 ** option to [sqlite3_db_config()] can be used to change the lookaside
1983 ** configuration on individual connections.)^ </dd>
1984 **
1985 ** [[SQLITE_CONFIG_PCACHE2]] <dt>SQLITE_CONFIG_PCACHE2</dt>
1986 ** <dd> ^(The SQLITE_CONFIG_PCACHE2 option takes a single argument which is
1987 ** a pointer to an [sqlite3_pcache_methods2] object. This object specifies
1988 ** the interface to a custom page cache implementation.)^
1989 ** ^SQLite makes a copy of the [sqlite3_pcache_methods2] object.</dd>
1990 **
1991 ** [[SQLITE_CONFIG_GETPCACHE2]] <dt>SQLITE_CONFIG_GETPCACHE2</dt>
1992 ** <dd> ^(The SQLITE_CONFIG_GETPCACHE2 option takes a single argument which
1993 ** is a pointer to an [sqlite3_pcache_methods2] object. SQLite copies of
1994 ** the current page cache implementation into that object.)^ </dd>
1995 **
1996 ** [[SQLITE_CONFIG_LOG]] <dt>SQLITE_CONFIG_LOG</dt>
1997 ** <dd> The SQLITE_CONFIG_LOG option is used to configure the SQLite
1998 ** global [error log].
1999 ** (^The SQLITE_CONFIG_LOG option takes two arguments: a pointer to a
2000 ** function with a call signature of void(*)(void*,int,const char*),
2001 ** and a pointer to void. ^If the function pointer is not NULL, it is
2002 ** invoked by [sqlite3_log()] to process each logging event. ^If the
2003 ** function pointer is NULL, the [sqlite3_log()] interface becomes a no-op.
2004 ** ^The void pointer that is the second argument to SQLITE_CONFIG_LOG is
2005 ** passed through as the first parameter to the application-defined logger
2006 ** function whenever that function is invoked. ^The second parameter to
2007 ** the logger function is a copy of the first parameter to the corresponding
2008 ** [sqlite3_log()] call and is intended to be a [result code] or an
2009 ** [extended result code]. ^The third parameter passed to the logger is
2010 ** log message after formatting via [sqlite3_snprintf()].
2011 ** The SQLite logging interface is not reentrant; the logger function
2012 ** supplied by the application must not invoke any SQLite interface.
2013 ** In a multi-threaded application, the application-defined logger
2014 ** function must be threadsafe. </dd>
2015 **
2016 ** [[SQLITE_CONFIG_URI]] <dt>SQLITE_CONFIG_URI
2017 ** <dd>^(The SQLITE_CONFIG_URI option takes a single argument of type int.
2018 ** If non-zero, then URI handling is globally enabled. If the parameter is zero,
2019 ** then URI handling is globally disabled.)^ ^If URI handling is globally
2020 ** enabled, all filenames passed to [sqlite3_open()], [sqlite3_open_v2()],
2021 ** [sqlite3_open16()] or
2022 ** specified as part of [ATTACH] commands are interpreted as URIs, regardless
2023 ** of whether or not the [SQLITE_OPEN_URI] flag is set when the database
2024 ** connection is opened. ^If it is globally disabled, filenames are
2025 ** only interpreted as URIs if the SQLITE_OPEN_URI flag is set when the
2026 ** database connection is opened. ^(By default, URI handling is globally
2027 ** disabled. The default value may be changed by compiling with the
2028 ** [SQLITE_USE_URI] symbol defined.)^
2029 **
2030 ** [[SQLITE_CONFIG_COVERING_INDEX_SCAN]] <dt>SQLITE_CONFIG_COVERING_INDEX_SCAN
2031 ** <dd>^The SQLITE_CONFIG_COVERING_INDEX_SCAN option takes a single integer
2032 ** argument which is interpreted as a boolean in order to enable or disable
2033 ** the use of covering indices for full table scans in the query optimizer.
2034 ** ^The default setting is determined
2035 ** by the [SQLITE_ALLOW_COVERING_INDEX_SCAN] compile-time option, or is "on"
2036 ** if that compile-time option is omitted.
2037 ** The ability to disable the use of covering indices for full table scans
2038 ** is because some incorrectly coded legacy applications might malfunction
2039 ** when the optimization is enabled. Providing the ability to
2040 ** disable the optimization allows the older, buggy application code to work
2041 ** without change even with newer versions of SQLite.
2042 **
2043 ** [[SQLITE_CONFIG_PCACHE]] [[SQLITE_CONFIG_GETPCACHE]]
2044 ** <dt>SQLITE_CONFIG_PCACHE and SQLITE_CONFIG_GETPCACHE
2045 ** <dd> These options are obsolete and should not be used by new code.
2046 ** They are retained for backwards compatibility but are now no-ops.
2047 ** </dd>
2048 **
2049 ** [[SQLITE_CONFIG_SQLLOG]]
2050 ** <dt>SQLITE_CONFIG_SQLLOG
2051 ** <dd>This option is only available if sqlite is compiled with the
2052 ** [SQLITE_ENABLE_SQLLOG] pre-processor macro defined. The first argument should
2053 ** be a pointer to a function of type void(*)(void*,sqlite3*,const char*, int).
2054 ** The second should be of type (void*). The callback is invoked by the library
2055 ** in three separate circumstances, identified by the value passed as the
2056 ** fourth parameter. If the fourth parameter is 0, then the database connection
2057 ** passed as the second argument has just been opened. The third argument
2058 ** points to a buffer containing the name of the main database file. If the
2059 ** fourth parameter is 1, then the SQL statement that the third parameter
2060 ** points to has just been executed. Or, if the fourth parameter is 2, then
2061 ** the connection being passed as the second parameter is being closed. The
2062 ** third parameter is passed NULL In this case. An example of using this
2063 ** configuration option can be seen in the "test_sqllog.c" source file in
2064 ** the canonical SQLite source tree.</dd>
2065 **
2066 ** [[SQLITE_CONFIG_MMAP_SIZE]]
2067 ** <dt>SQLITE_CONFIG_MMAP_SIZE
2068 ** <dd>^SQLITE_CONFIG_MMAP_SIZE takes two 64-bit integer (sqlite3_int64) values
2069 ** that are the default mmap size limit (the default setting for
2070 ** [PRAGMA mmap_size]) and the maximum allowed mmap size limit.
2071 ** ^The default setting can be overridden by each database connection using
2072 ** either the [PRAGMA mmap_size] command, or by using the
2073 ** [SQLITE_FCNTL_MMAP_SIZE] file control. ^(The maximum allowed mmap size
2074 ** will be silently truncated if necessary so that it does not exceed the
2075 ** compile-time maximum mmap size set by the
2076 ** [SQLITE_MAX_MMAP_SIZE] compile-time option.)^
2077 ** ^If either argument to this option is negative, then that argument is
2078 ** changed to its compile-time default.
2079 **
2080 ** [[SQLITE_CONFIG_WIN32_HEAPSIZE]]
2081 ** <dt>SQLITE_CONFIG_WIN32_HEAPSIZE
2082 ** <dd>^The SQLITE_CONFIG_WIN32_HEAPSIZE option is only available if SQLite is
2083 ** compiled for Windows with the [SQLITE_WIN32_MALLOC] pre-processor macro
2084 ** defined. ^SQLITE_CONFIG_WIN32_HEAPSIZE takes a 32-bit unsigned integer value
2085 ** that specifies the maximum size of the created heap.
2086 **
2087 ** [[SQLITE_CONFIG_PCACHE_HDRSZ]]
2088 ** <dt>SQLITE_CONFIG_PCACHE_HDRSZ
2089 ** <dd>^The SQLITE_CONFIG_PCACHE_HDRSZ option takes a single parameter which
2090 ** is a pointer to an integer and writes into that integer the number of extra
2091 ** bytes per page required for each page in [SQLITE_CONFIG_PAGECACHE].
2092 ** The amount of extra space required can change depending on the compiler,
2093 ** target platform, and SQLite version.
2094 **
2095 ** [[SQLITE_CONFIG_PMASZ]]
2096 ** <dt>SQLITE_CONFIG_PMASZ
2097 ** <dd>^The SQLITE_CONFIG_PMASZ option takes a single parameter which
2098 ** is an unsigned integer and sets the "Minimum PMA Size" for the multithreaded
2099 ** sorter to that integer. The default minimum PMA Size is set by the
2100 ** [SQLITE_SORTER_PMASZ] compile-time option. New threads are launched
2101 ** to help with sort operations when multithreaded sorting
2102 ** is enabled (using the [PRAGMA threads] command) and the amount of content
2103 ** to be sorted exceeds the page size times the minimum of the
2104 ** [PRAGMA cache_size] setting and this value.
2105 **
2106 ** [[SQLITE_CONFIG_STMTJRNL_SPILL]]
2107 ** <dt>SQLITE_CONFIG_STMTJRNL_SPILL
2108 ** <dd>^The SQLITE_CONFIG_STMTJRNL_SPILL option takes a single parameter which
2109 ** becomes the [statement journal] spill-to-disk threshold.
2110 ** [Statement journals] are held in memory until their size (in bytes)
2111 ** exceeds this threshold, at which point they are written to disk.
2112 ** Or if the threshold is -1, statement journals are always held
2113 ** exclusively in memory.
2114 ** Since many statement journals never become large, setting the spill
2115 ** threshold to a value such as 64KiB can greatly reduce the amount of
2116 ** I/O required to support statement rollback.
2117 ** The default value for this setting is controlled by the
2118 ** [SQLITE_STMTJRNL_SPILL] compile-time option.
2119 **
2120 ** [[SQLITE_CONFIG_SORTERREF_SIZE]]
2121 ** <dt>SQLITE_CONFIG_SORTERREF_SIZE
2122 ** <dd>The SQLITE_CONFIG_SORTERREF_SIZE option accepts a single parameter
2123 ** of type (int) - the new value of the sorter-reference size threshold.
2124 ** Usually, when SQLite uses an external sort to order records according
2125 ** to an ORDER BY clause, all fields required by the caller are present in the
2126 ** sorted records. However, if SQLite determines based on the declared type
2127 ** of a table column that its values are likely to be very large - larger
2128 ** than the configured sorter-reference size threshold - then a reference
2129 ** is stored in each sorted record and the required column values loaded
2130 ** from the database as records are returned in sorted order. The default
2131 ** value for this option is to never use this optimization. Specifying a
2132 ** negative value for this option restores the default behavior.
2133 ** This option is only available if SQLite is compiled with the
2134 ** [SQLITE_ENABLE_SORTER_REFERENCES] compile-time option.
2135 **
2136 ** [[SQLITE_CONFIG_MEMDB_MAXSIZE]]
2137 ** <dt>SQLITE_CONFIG_MEMDB_MAXSIZE
2138 ** <dd>The SQLITE_CONFIG_MEMDB_MAXSIZE option accepts a single parameter
2139 ** [sqlite3_int64] parameter which is the default maximum size for an in-memory
2140 ** database created using [sqlite3_deserialize()]. This default maximum
2141 ** size can be adjusted up or down for individual databases using the
2142 ** [SQLITE_FCNTL_SIZE_LIMIT] [sqlite3_file_control|file-control]. If this
2143 ** configuration setting is never used, then the default maximum is determined
2144 ** by the [SQLITE_MEMDB_DEFAULT_MAXSIZE] compile-time option. If that
2145 ** compile-time option is not set, then the default maximum is 1073741824.
2146 **
2147 ** [[SQLITE_CONFIG_ROWID_IN_VIEW]]
2148 ** <dt>SQLITE_CONFIG_ROWID_IN_VIEW
2149 ** <dd>The SQLITE_CONFIG_ROWID_IN_VIEW option enables or disables the ability
2150 ** for VIEWs to have a ROWID. The capability can only be enabled if SQLite is
2151 ** compiled with -DSQLITE_ALLOW_ROWID_IN_VIEW, in which case the capability
2152 ** defaults to on. This configuration option queries the current setting or
2153 ** changes the setting to off or on. The argument is a pointer to an integer.
2154 ** If that integer initially holds a value of 1, then the ability for VIEWs to
2155 ** have ROWIDs is activated. If the integer initially holds zero, then the
2156 ** ability is deactivated. Any other initial value for the integer leaves the
2157 ** setting unchanged. After changes, if any, the integer is written with
2158 ** a 1 or 0, if the ability for VIEWs to have ROWIDs is on or off. If SQLite
2159 ** is compiled without -DSQLITE_ALLOW_ROWID_IN_VIEW (which is the usual and
2160 ** recommended case) then the integer is always filled with zero, regardless
2161 ** if its initial value.
2162 ** </dl>
2163 */
2164 #define SQLITE_CONFIG_SINGLETHREAD 1 /* nil */
2165 #define SQLITE_CONFIG_MULTITHREAD 2 /* nil */
2166 #define SQLITE_CONFIG_SERIALIZED 3 /* nil */
2167 #define SQLITE_CONFIG_MALLOC 4 /* sqlite3_mem_methods* */
2168 #define SQLITE_CONFIG_GETMALLOC 5 /* sqlite3_mem_methods* */
2169 #define SQLITE_CONFIG_SCRATCH 6 /* No longer used */
2170 #define SQLITE_CONFIG_PAGECACHE 7 /* void*, int sz, int N */
2171 #define SQLITE_CONFIG_HEAP 8 /* void*, int nByte, int min */
2172 #define SQLITE_CONFIG_MEMSTATUS 9 /* boolean */
2173 #define SQLITE_CONFIG_MUTEX 10 /* sqlite3_mutex_methods* */
2174 #define SQLITE_CONFIG_GETMUTEX 11 /* sqlite3_mutex_methods* */
2175 /* previously SQLITE_CONFIG_CHUNKALLOC 12 which is now unused. */
2176 #define SQLITE_CONFIG_LOOKASIDE 13 /* int int */
2177 #define SQLITE_CONFIG_PCACHE 14 /* no-op */
2178 #define SQLITE_CONFIG_GETPCACHE 15 /* no-op */
2179 #define SQLITE_CONFIG_LOG 16 /* xFunc, void* */
2180 #define SQLITE_CONFIG_URI 17 /* int */
2181 #define SQLITE_CONFIG_PCACHE2 18 /* sqlite3_pcache_methods2* */
2182 #define SQLITE_CONFIG_GETPCACHE2 19 /* sqlite3_pcache_methods2* */
2183 #define SQLITE_CONFIG_COVERING_INDEX_SCAN 20 /* int */
2184 #define SQLITE_CONFIG_SQLLOG 21 /* xSqllog, void* */
2185 #define SQLITE_CONFIG_MMAP_SIZE 22 /* sqlite3_int64, sqlite3_int64 */
2186 #define SQLITE_CONFIG_WIN32_HEAPSIZE 23 /* int nByte */
2187 #define SQLITE_CONFIG_PCACHE_HDRSZ 24 /* int *psz */
2188 #define SQLITE_CONFIG_PMASZ 25 /* unsigned int szPma */
2189 #define SQLITE_CONFIG_STMTJRNL_SPILL 26 /* int nByte */
2190 #define SQLITE_CONFIG_SMALL_MALLOC 27 /* boolean */
2191 #define SQLITE_CONFIG_SORTERREF_SIZE 28 /* int nByte */
2192 #define SQLITE_CONFIG_MEMDB_MAXSIZE 29 /* sqlite3_int64 */
2193 #define SQLITE_CONFIG_ROWID_IN_VIEW 30 /* int* */
2194
2195 /*
2196 ** CAPI3REF: Database Connection Configuration Options
2197 **
2198 ** These constants are the available integer configuration options that
2199 ** can be passed as the second argument to the [sqlite3_db_config()] interface.
2200 **
2201 ** New configuration options may be added in future releases of SQLite.
2202 ** Existing configuration options might be discontinued. Applications
2203 ** should check the return code from [sqlite3_db_config()] to make sure that
2204 ** the call worked. ^The [sqlite3_db_config()] interface will return a
2205 ** non-zero [error code] if a discontinued or unsupported configuration option
2206 ** is invoked.
2207 **
2208 ** <dl>
2209 ** [[SQLITE_DBCONFIG_LOOKASIDE]]
2210 ** <dt>SQLITE_DBCONFIG_LOOKASIDE</dt>
2211 ** <dd> ^This option takes three additional arguments that determine the
2212 ** [lookaside memory allocator] configuration for the [database connection].
2213 ** ^The first argument (the third parameter to [sqlite3_db_config()] is a
2214 ** pointer to a memory buffer to use for lookaside memory.
2215 ** ^The first argument after the SQLITE_DBCONFIG_LOOKASIDE verb
2216 ** may be NULL in which case SQLite will allocate the
2217 ** lookaside buffer itself using [sqlite3_malloc()]. ^The second argument is the
2218 ** size of each lookaside buffer slot. ^The third argument is the number of
2219 ** slots. The size of the buffer in the first argument must be greater than
2220 ** or equal to the product of the second and third arguments. The buffer
2221 ** must be aligned to an 8-byte boundary. ^If the second argument to
2222 ** SQLITE_DBCONFIG_LOOKASIDE is not a multiple of 8, it is internally
2223 ** rounded down to the next smaller multiple of 8. ^(The lookaside memory
2224 ** configuration for a database connection can only be changed when that
2225 ** connection is not currently using lookaside memory, or in other words
2226 ** when the "current value" returned by
2227 ** [sqlite3_db_status](D,[SQLITE_DBSTATUS_LOOKASIDE_USED],...) is zero.
2228 ** Any attempt to change the lookaside memory configuration when lookaside
2229 ** memory is in use leaves the configuration unchanged and returns
2230 ** [SQLITE_BUSY].)^</dd>
2231 **
2232 ** [[SQLITE_DBCONFIG_ENABLE_FKEY]]
2233 ** <dt>SQLITE_DBCONFIG_ENABLE_FKEY</dt>
2234 ** <dd> ^This option is used to enable or disable the enforcement of
2235 ** [foreign key constraints]. There should be two additional arguments.
2236 ** The first argument is an integer which is 0 to disable FK enforcement,
2237 ** positive to enable FK enforcement or negative to leave FK enforcement
2238 ** unchanged. The second parameter is a pointer to an integer into which
2239 ** is written 0 or 1 to indicate whether FK enforcement is off or on
2240 ** following this call. The second parameter may be a NULL pointer, in
2241 ** which case the FK enforcement setting is not reported back. </dd>
2242 **
2243 ** [[SQLITE_DBCONFIG_ENABLE_TRIGGER]]
2244 ** <dt>SQLITE_DBCONFIG_ENABLE_TRIGGER</dt>
2245 ** <dd> ^This option is used to enable or disable [CREATE TRIGGER | triggers].
2246 ** There should be two additional arguments.
2247 ** The first argument is an integer which is 0 to disable triggers,
2248 ** positive to enable triggers or negative to leave the setting unchanged.
2249 ** The second parameter is a pointer to an integer into which
2250 ** is written 0 or 1 to indicate whether triggers are disabled or enabled
2251 ** following this call. The second parameter may be a NULL pointer, in
2252 ** which case the trigger setting is not reported back.
2253 **
2254 ** <p>Originally this option disabled all triggers. ^(However, since
2255 ** SQLite version 3.35.0, TEMP triggers are still allowed even if
2256 ** this option is off. So, in other words, this option now only disables
2257 ** triggers in the main database schema or in the schemas of ATTACH-ed
2258 ** databases.)^ </dd>
2259 **
2260 ** [[SQLITE_DBCONFIG_ENABLE_VIEW]]
2261 ** <dt>SQLITE_DBCONFIG_ENABLE_VIEW</dt>
2262 ** <dd> ^This option is used to enable or disable [CREATE VIEW | views].
2263 ** There should be two additional arguments.
2264 ** The first argument is an integer which is 0 to disable views,
2265 ** positive to enable views or negative to leave the setting unchanged.
2266 ** The second parameter is a pointer to an integer into which
2267 ** is written 0 or 1 to indicate whether views are disabled or enabled
2268 ** following this call. The second parameter may be a NULL pointer, in
2269 ** which case the view setting is not reported back.
2270 **
2271 ** <p>Originally this option disabled all views. ^(However, since
2272 ** SQLite version 3.35.0, TEMP views are still allowed even if
2273 ** this option is off. So, in other words, this option now only disables
2274 ** views in the main database schema or in the schemas of ATTACH-ed
2275 ** databases.)^ </dd>
2276 **
2277 ** [[SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER]]
2278 ** <dt>SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER</dt>
2279 ** <dd> ^This option is used to enable or disable the
2280 ** [fts3_tokenizer()] function which is part of the
2281 ** [FTS3] full-text search engine extension.
2282 ** There should be two additional arguments.
2283 ** The first argument is an integer which is 0 to disable fts3_tokenizer() or
2284 ** positive to enable fts3_tokenizer() or negative to leave the setting
2285 ** unchanged.
2286 ** The second parameter is a pointer to an integer into which
2287 ** is written 0 or 1 to indicate whether fts3_tokenizer is disabled or enabled
2288 ** following this call. The second parameter may be a NULL pointer, in
2289 ** which case the new setting is not reported back. </dd>
2290 **
2291 ** [[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION]]
2292 ** <dt>SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION</dt>
2293 ** <dd> ^This option is used to enable or disable the [sqlite3_load_extension()]
2294 ** interface independently of the [load_extension()] SQL function.
2295 ** The [sqlite3_enable_load_extension()] API enables or disables both the
2296 ** C-API [sqlite3_load_extension()] and the SQL function [load_extension()].
2297 ** There should be two additional arguments.
2298 ** When the first argument to this interface is 1, then only the C-API is
2299 ** enabled and the SQL function remains disabled. If the first argument to
2300 ** this interface is 0, then both the C-API and the SQL function are disabled.
2301 ** If the first argument is -1, then no changes are made to state of either the
2302 ** C-API or the SQL function.
2303 ** The second parameter is a pointer to an integer into which
2304 ** is written 0 or 1 to indicate whether [sqlite3_load_extension()] interface
2305 ** is disabled or enabled following this call. The second parameter may
2306 ** be a NULL pointer, in which case the new setting is not reported back.
2307 ** </dd>
2308 **
2309 ** [[SQLITE_DBCONFIG_MAINDBNAME]] <dt>SQLITE_DBCONFIG_MAINDBNAME</dt>
2310 ** <dd> ^This option is used to change the name of the "main" database
2311 ** schema. ^The sole argument is a pointer to a constant UTF8 string
2312 ** which will become the new schema name in place of "main". ^SQLite
2313 ** does not make a copy of the new main schema name string, so the application
2314 ** must ensure that the argument passed into this DBCONFIG option is unchanged
2315 ** until after the database connection closes.
2316 ** </dd>
2317 **
2318 ** [[SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE]]
2319 ** <dt>SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE</dt>
2320 ** <dd> Usually, when a database in wal mode is closed or detached from a
2321 ** database handle, SQLite checks if this will mean that there are now no
2322 ** connections at all to the database. If so, it performs a checkpoint
2323 ** operation before closing the connection. This option may be used to
2324 ** override this behavior. The first parameter passed to this operation
2325 ** is an integer - positive to disable checkpoints-on-close, or zero (the
2326 ** default) to enable them, and negative to leave the setting unchanged.
2327 ** The second parameter is a pointer to an integer
2328 ** into which is written 0 or 1 to indicate whether checkpoints-on-close
2329 ** have been disabled - 0 if they are not disabled, 1 if they are.
2330 ** </dd>
2331 **
2332 ** [[SQLITE_DBCONFIG_ENABLE_QPSG]] <dt>SQLITE_DBCONFIG_ENABLE_QPSG</dt>
2333 ** <dd>^(The SQLITE_DBCONFIG_ENABLE_QPSG option activates or deactivates
2334 ** the [query planner stability guarantee] (QPSG). When the QPSG is active,
2335 ** a single SQL query statement will always use the same algorithm regardless
2336 ** of values of [bound parameters].)^ The QPSG disables some query optimizations
2337 ** that look at the values of bound parameters, which can make some queries
2338 ** slower. But the QPSG has the advantage of more predictable behavior. With
2339 ** the QPSG active, SQLite will always use the same query plan in the field as
2340 ** was used during testing in the lab.
2341 ** The first argument to this setting is an integer which is 0 to disable
2342 ** the QPSG, positive to enable QPSG, or negative to leave the setting
2343 ** unchanged. The second parameter is a pointer to an integer into which
2344 ** is written 0 or 1 to indicate whether the QPSG is disabled or enabled
2345 ** following this call.
2346 ** </dd>
2347 **
2348 ** [[SQLITE_DBCONFIG_TRIGGER_EQP]] <dt>SQLITE_DBCONFIG_TRIGGER_EQP</dt>
2349 ** <dd> By default, the output of EXPLAIN QUERY PLAN commands does not
2350 ** include output for any operations performed by trigger programs. This
2351 ** option is used to set or clear (the default) a flag that governs this
2352 ** behavior. The first parameter passed to this operation is an integer -
2353 ** positive to enable output for trigger programs, or zero to disable it,
2354 ** or negative to leave the setting unchanged.
2355 ** The second parameter is a pointer to an integer into which is written
2356 ** 0 or 1 to indicate whether output-for-triggers has been disabled - 0 if
2357 ** it is not disabled, 1 if it is.
2358 ** </dd>
2359 **
2360 ** [[SQLITE_DBCONFIG_RESET_DATABASE]] <dt>SQLITE_DBCONFIG_RESET_DATABASE</dt>
2361 ** <dd> Set the SQLITE_DBCONFIG_RESET_DATABASE flag and then run
2362 ** [VACUUM] in order to reset a database back to an empty database
2363 ** with no schema and no content. The following process works even for
2364 ** a badly corrupted database file:
2365 ** <ol>
2366 ** <li> If the database connection is newly opened, make sure it has read the
2367 ** database schema by preparing then discarding some query against the
2368 ** database, or calling sqlite3_table_column_metadata(), ignoring any
2369 ** errors. This step is only necessary if the application desires to keep
2370 ** the database in WAL mode after the reset if it was in WAL mode before
2371 ** the reset.
2372 ** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 1, 0);
2373 ** <li> [sqlite3_exec](db, "[VACUUM]", 0, 0, 0);
2374 ** <li> sqlite3_db_config(db, SQLITE_DBCONFIG_RESET_DATABASE, 0, 0);
2375 ** </ol>
2376 ** Because resetting a database is destructive and irreversible, the
2377 ** process requires the use of this obscure API and multiple steps to
2378 ** help ensure that it does not happen by accident. Because this
2379 ** feature must be capable of resetting corrupt databases, and
2380 ** shutting down virtual tables may require access to that corrupt
2381 ** storage, the library must abandon any installed virtual tables
2382 ** without calling their xDestroy() methods.
2383 **
2384 ** [[SQLITE_DBCONFIG_DEFENSIVE]] <dt>SQLITE_DBCONFIG_DEFENSIVE</dt>
2385 ** <dd>The SQLITE_DBCONFIG_DEFENSIVE option activates or deactivates the
2386 ** "defensive" flag for a database connection. When the defensive
2387 ** flag is enabled, language features that allow ordinary SQL to
2388 ** deliberately corrupt the database file are disabled. The disabled
2389 ** features include but are not limited to the following:
2390 ** <ul>
2391 ** <li> The [PRAGMA writable_schema=ON] statement.
2392 ** <li> The [PRAGMA journal_mode=OFF] statement.
2393 ** <li> The [PRAGMA schema_version=N] statement.
2394 ** <li> Writes to the [sqlite_dbpage] virtual table.
2395 ** <li> Direct writes to [shadow tables].
2396 ** </ul>
2397 ** </dd>
2398 **
2399 ** [[SQLITE_DBCONFIG_WRITABLE_SCHEMA]] <dt>SQLITE_DBCONFIG_WRITABLE_SCHEMA</dt>
2400 ** <dd>The SQLITE_DBCONFIG_WRITABLE_SCHEMA option activates or deactivates the
2401 ** "writable_schema" flag. This has the same effect and is logically equivalent
2402 ** to setting [PRAGMA writable_schema=ON] or [PRAGMA writable_schema=OFF].
2403 ** The first argument to this setting is an integer which is 0 to disable
2404 ** the writable_schema, positive to enable writable_schema, or negative to
2405 ** leave the setting unchanged. The second parameter is a pointer to an
2406 ** integer into which is written 0 or 1 to indicate whether the writable_schema
2407 ** is enabled or disabled following this call.
2408 ** </dd>
2409 **
2410 ** [[SQLITE_DBCONFIG_LEGACY_ALTER_TABLE]]
2411 ** <dt>SQLITE_DBCONFIG_LEGACY_ALTER_TABLE</dt>
2412 ** <dd>The SQLITE_DBCONFIG_LEGACY_ALTER_TABLE option activates or deactivates
2413 ** the legacy behavior of the [ALTER TABLE RENAME] command such it
2414 ** behaves as it did prior to [version 3.24.0] (2018-06-04). See the
2415 ** "Compatibility Notice" on the [ALTER TABLE RENAME documentation] for
2416 ** additional information. This feature can also be turned on and off
2417 ** using the [PRAGMA legacy_alter_table] statement.
2418 ** </dd>
2419 **
2420 ** [[SQLITE_DBCONFIG_DQS_DML]]
2421 ** <dt>SQLITE_DBCONFIG_DQS_DML</dt>
2422 ** <dd>The SQLITE_DBCONFIG_DQS_DML option activates or deactivates
2423 ** the legacy [double-quoted string literal] misfeature for DML statements
2424 ** only, that is DELETE, INSERT, SELECT, and UPDATE statements. The
2425 ** default value of this setting is determined by the [-DSQLITE_DQS]
2426 ** compile-time option.
2427 ** </dd>
2428 **
2429 ** [[SQLITE_DBCONFIG_DQS_DDL]]
2430 ** <dt>SQLITE_DBCONFIG_DQS_DDL</dt>
2431 ** <dd>The SQLITE_DBCONFIG_DQS option activates or deactivates
2432 ** the legacy [double-quoted string literal] misfeature for DDL statements,
2433 ** such as CREATE TABLE and CREATE INDEX. The
2434 ** default value of this setting is determined by the [-DSQLITE_DQS]
2435 ** compile-time option.
2436 ** </dd>
2437 **
2438 ** [[SQLITE_DBCONFIG_TRUSTED_SCHEMA]]
2439 ** <dt>SQLITE_DBCONFIG_TRUSTED_SCHEMA</dt>
2440 ** <dd>The SQLITE_DBCONFIG_TRUSTED_SCHEMA option tells SQLite to
2441 ** assume that database schemas are untainted by malicious content.
2442 ** When the SQLITE_DBCONFIG_TRUSTED_SCHEMA option is disabled, SQLite
2443 ** takes additional defensive steps to protect the application from harm
2444 ** including:
2445 ** <ul>
2446 ** <li> Prohibit the use of SQL functions inside triggers, views,
2447 ** CHECK constraints, DEFAULT clauses, expression indexes,
2448 ** partial indexes, or generated columns
2449 ** unless those functions are tagged with [SQLITE_INNOCUOUS].
2450 ** <li> Prohibit the use of virtual tables inside of triggers or views
2451 ** unless those virtual tables are tagged with [SQLITE_VTAB_INNOCUOUS].
2452 ** </ul>
2453 ** This setting defaults to "on" for legacy compatibility, however
2454 ** all applications are advised to turn it off if possible. This setting
2455 ** can also be controlled using the [PRAGMA trusted_schema] statement.
2456 ** </dd>
2457 **
2458 ** [[SQLITE_DBCONFIG_LEGACY_FILE_FORMAT]]
2459 ** <dt>SQLITE_DBCONFIG_LEGACY_FILE_FORMAT</dt>
2460 ** <dd>The SQLITE_DBCONFIG_LEGACY_FILE_FORMAT option activates or deactivates
2461 ** the legacy file format flag. When activated, this flag causes all newly
2462 ** created database file to have a schema format version number (the 4-byte
2463 ** integer found at offset 44 into the database header) of 1. This in turn
2464 ** means that the resulting database file will be readable and writable by
2465 ** any SQLite version back to 3.0.0 ([dateof:3.0.0]). Without this setting,
2466 ** newly created databases are generally not understandable by SQLite versions
2467 ** prior to 3.3.0 ([dateof:3.3.0]). As these words are written, there
2468 ** is now scarcely any need to generate database files that are compatible
2469 ** all the way back to version 3.0.0, and so this setting is of little
2470 ** practical use, but is provided so that SQLite can continue to claim the
2471 ** ability to generate new database files that are compatible with version
2472 ** 3.0.0.
2473 ** <p>Note that when the SQLITE_DBCONFIG_LEGACY_FILE_FORMAT setting is on,
2474 ** the [VACUUM] command will fail with an obscure error when attempting to
2475 ** process a table with generated columns and a descending index. This is
2476 ** not considered a bug since SQLite versions 3.3.0 and earlier do not support
2477 ** either generated columns or descending indexes.
2478 ** </dd>
2479 **
2480 ** [[SQLITE_DBCONFIG_STMT_SCANSTATUS]]
2481 ** <dt>SQLITE_DBCONFIG_STMT_SCANSTATUS</dt>
2482 ** <dd>The SQLITE_DBCONFIG_STMT_SCANSTATUS option is only useful in
2483 ** SQLITE_ENABLE_STMT_SCANSTATUS builds. In this case, it sets or clears
2484 ** a flag that enables collection of the sqlite3_stmt_scanstatus_v2()
2485 ** statistics. For statistics to be collected, the flag must be set on
2486 ** the database handle both when the SQL statement is prepared and when it
2487 ** is stepped. The flag is set (collection of statistics is enabled)
2488 ** by default. This option takes two arguments: an integer and a pointer to
2489 ** an integer.. The first argument is 1, 0, or -1 to enable, disable, or
2490 ** leave unchanged the statement scanstatus option. If the second argument
2491 ** is not NULL, then the value of the statement scanstatus setting after
2492 ** processing the first argument is written into the integer that the second
2493 ** argument points to.
2494 ** </dd>
2495 **
2496 ** [[SQLITE_DBCONFIG_REVERSE_SCANORDER]]
2497 ** <dt>SQLITE_DBCONFIG_REVERSE_SCANORDER</dt>
2498 ** <dd>The SQLITE_DBCONFIG_REVERSE_SCANORDER option changes the default order
2499 ** in which tables and indexes are scanned so that the scans start at the end
2500 ** and work toward the beginning rather than starting at the beginning and
2501 ** working toward the end. Setting SQLITE_DBCONFIG_REVERSE_SCANORDER is the
2502 ** same as setting [PRAGMA reverse_unordered_selects]. This option takes
2503 ** two arguments which are an integer and a pointer to an integer. The first
2504 ** argument is 1, 0, or -1 to enable, disable, or leave unchanged the
2505 ** reverse scan order flag, respectively. If the second argument is not NULL,
2506 ** then 0 or 1 is written into the integer that the second argument points to
2507 ** depending on if the reverse scan order flag is set after processing the
2508 ** first argument.
2509 ** </dd>
2510 **
2511 ** </dl>
2512 */
2513 #define SQLITE_DBCONFIG_MAINDBNAME 1000 /* const char* */
2514 #define SQLITE_DBCONFIG_LOOKASIDE 1001 /* void* int int */
2515 #define SQLITE_DBCONFIG_ENABLE_FKEY 1002 /* int int* */
2516 #define SQLITE_DBCONFIG_ENABLE_TRIGGER 1003 /* int int* */
2517 #define SQLITE_DBCONFIG_ENABLE_FTS3_TOKENIZER 1004 /* int int* */
2518 #define SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION 1005 /* int int* */
2519 #define SQLITE_DBCONFIG_NO_CKPT_ON_CLOSE 1006 /* int int* */
2520 #define SQLITE_DBCONFIG_ENABLE_QPSG 1007 /* int int* */
2521 #define SQLITE_DBCONFIG_TRIGGER_EQP 1008 /* int int* */
2522 #define SQLITE_DBCONFIG_RESET_DATABASE 1009 /* int int* */
2523 #define SQLITE_DBCONFIG_DEFENSIVE 1010 /* int int* */
2524 #define SQLITE_DBCONFIG_WRITABLE_SCHEMA 1011 /* int int* */
2525 #define SQLITE_DBCONFIG_LEGACY_ALTER_TABLE 1012 /* int int* */
2526 #define SQLITE_DBCONFIG_DQS_DML 1013 /* int int* */
2527 #define SQLITE_DBCONFIG_DQS_DDL 1014 /* int int* */
2528 #define SQLITE_DBCONFIG_ENABLE_VIEW 1015 /* int int* */
2529 #define SQLITE_DBCONFIG_LEGACY_FILE_FORMAT 1016 /* int int* */
2530 #define SQLITE_DBCONFIG_TRUSTED_SCHEMA 1017 /* int int* */
2531 #define SQLITE_DBCONFIG_STMT_SCANSTATUS 1018 /* int int* */
2532 #define SQLITE_DBCONFIG_REVERSE_SCANORDER 1019 /* int int* */
2533 #define SQLITE_DBCONFIG_MAX 1019 /* Largest DBCONFIG */
2534
2535 /*
2536 ** CAPI3REF: Enable Or Disable Extended Result Codes
2537 ** METHOD: sqlite3
2538 **
2539 ** ^The sqlite3_extended_result_codes() routine enables or disables the
2540 ** [extended result codes] feature of SQLite. ^The extended result
2541 ** codes are disabled by default for historical compatibility.
2542 */
2543 SQLITE_API int sqlite3_extended_result_codes(sqlite3*, int onoff);
2544
2545 /*
2546 ** CAPI3REF: Last Insert Rowid
2547 ** METHOD: sqlite3
2548 **
2549 ** ^Each entry in most SQLite tables (except for [WITHOUT ROWID] tables)
2550 ** has a unique 64-bit signed
2551 ** integer key called the [ROWID | "rowid"]. ^The rowid is always available
2552 ** as an undeclared column named ROWID, OID, or _ROWID_ as long as those
2553 ** names are not also used by explicitly declared columns. ^If
2554 ** the table has a column of type [INTEGER PRIMARY KEY] then that column
2555 ** is another alias for the rowid.
2556 **
2557 ** ^The sqlite3_last_insert_rowid(D) interface usually returns the [rowid] of
2558 ** the most recent successful [INSERT] into a rowid table or [virtual table]
2559 ** on database connection D. ^Inserts into [WITHOUT ROWID] tables are not
2560 ** recorded. ^If no successful [INSERT]s into rowid tables have ever occurred
2561 ** on the database connection D, then sqlite3_last_insert_rowid(D) returns
2562 ** zero.
2563 **
2564 ** As well as being set automatically as rows are inserted into database
2565 ** tables, the value returned by this function may be set explicitly by
2566 ** [sqlite3_set_last_insert_rowid()]
2567 **
2568 ** Some virtual table implementations may INSERT rows into rowid tables as
2569 ** part of committing a transaction (e.g. to flush data accumulated in memory
2570 ** to disk). In this case subsequent calls to this function return the rowid
2571 ** associated with these internal INSERT operations, which leads to
2572 ** unintuitive results. Virtual table implementations that do write to rowid
2573 ** tables in this way can avoid this problem by restoring the original
2574 ** rowid value using [sqlite3_set_last_insert_rowid()] before returning
2575 ** control to the user.
2576 **
2577 ** ^(If an [INSERT] occurs within a trigger then this routine will
2578 ** return the [rowid] of the inserted row as long as the trigger is
2579 ** running. Once the trigger program ends, the value returned
2580 ** by this routine reverts to what it was before the trigger was fired.)^
2581 **
2582 ** ^An [INSERT] that fails due to a constraint violation is not a
2583 ** successful [INSERT] and does not change the value returned by this
2584 ** routine. ^Thus INSERT OR FAIL, INSERT OR IGNORE, INSERT OR ROLLBACK,
2585 ** and INSERT OR ABORT make no changes to the return value of this
2586 ** routine when their insertion fails. ^(When INSERT OR REPLACE
2587 ** encounters a constraint violation, it does not fail. The
2588 ** INSERT continues to completion after deleting rows that caused
2589 ** the constraint problem so INSERT OR REPLACE will always change
2590 ** the return value of this interface.)^
2591 **
2592 ** ^For the purposes of this routine, an [INSERT] is considered to
2593 ** be successful even if it is subsequently rolled back.
2594 **
2595 ** This function is accessible to SQL statements via the
2596 ** [last_insert_rowid() SQL function].
2597 **
2598 ** If a separate thread performs a new [INSERT] on the same
2599 ** database connection while the [sqlite3_last_insert_rowid()]
2600 ** function is running and thus changes the last insert [rowid],
2601 ** then the value returned by [sqlite3_last_insert_rowid()] is
2602 ** unpredictable and might not equal either the old or the new
2603 ** last insert [rowid].
2604 */
2605 SQLITE_API sqlite3_int64 sqlite3_last_insert_rowid(sqlite3*);
2606
2607 /*
2608 ** CAPI3REF: Set the Last Insert Rowid value.
2609 ** METHOD: sqlite3
2610 **
2611 ** The sqlite3_set_last_insert_rowid(D, R) method allows the application to
2612 ** set the value returned by calling sqlite3_last_insert_rowid(D) to R
2613 ** without inserting a row into the database.
2614 */
2615 SQLITE_API void sqlite3_set_last_insert_rowid(sqlite3*,sqlite3_int64);
2616
2617 /*
2618 ** CAPI3REF: Count The Number Of Rows Modified
2619 ** METHOD: sqlite3
2620 **
2621 ** ^These functions return the number of rows modified, inserted or
2622 ** deleted by the most recently completed INSERT, UPDATE or DELETE
2623 ** statement on the database connection specified by the only parameter.
2624 ** The two functions are identical except for the type of the return value
2625 ** and that if the number of rows modified by the most recent INSERT, UPDATE
2626 ** or DELETE is greater than the maximum value supported by type "int", then
2627 ** the return value of sqlite3_changes() is undefined. ^Executing any other
2628 ** type of SQL statement does not modify the value returned by these functions.
2629 **
2630 ** ^Only changes made directly by the INSERT, UPDATE or DELETE statement are
2631 ** considered - auxiliary changes caused by [CREATE TRIGGER | triggers],
2632 ** [foreign key actions] or [REPLACE] constraint resolution are not counted.
2633 **
2634 ** Changes to a view that are intercepted by
2635 ** [INSTEAD OF trigger | INSTEAD OF triggers] are not counted. ^The value
2636 ** returned by sqlite3_changes() immediately after an INSERT, UPDATE or
2637 ** DELETE statement run on a view is always zero. Only changes made to real
2638 ** tables are counted.
2639 **
2640 ** Things are more complicated if the sqlite3_changes() function is
2641 ** executed while a trigger program is running. This may happen if the
2642 ** program uses the [changes() SQL function], or if some other callback
2643 ** function invokes sqlite3_changes() directly. Essentially:
2644 **
2645 ** <ul>
2646 ** <li> ^(Before entering a trigger program the value returned by
2647 ** sqlite3_changes() function is saved. After the trigger program
2648 ** has finished, the original value is restored.)^
2649 **
2650 ** <li> ^(Within a trigger program each INSERT, UPDATE and DELETE
2651 ** statement sets the value returned by sqlite3_changes()
2652 ** upon completion as normal. Of course, this value will not include
2653 ** any changes performed by sub-triggers, as the sqlite3_changes()
2654 ** value will be saved and restored after each sub-trigger has run.)^
2655 ** </ul>
2656 **
2657 ** ^This means that if the changes() SQL function (or similar) is used
2658 ** by the first INSERT, UPDATE or DELETE statement within a trigger, it
2659 ** returns the value as set when the calling statement began executing.
2660 ** ^If it is used by the second or subsequent such statement within a trigger
2661 ** program, the value returned reflects the number of rows modified by the
2662 ** previous INSERT, UPDATE or DELETE statement within the same trigger.
2663 **
2664 ** If a separate thread makes changes on the same database connection
2665 ** while [sqlite3_changes()] is running then the value returned
2666 ** is unpredictable and not meaningful.
2667 **
2668 ** See also:
2669 ** <ul>
2670 ** <li> the [sqlite3_total_changes()] interface
2671 ** <li> the [count_changes pragma]
2672 ** <li> the [changes() SQL function]
2673 ** <li> the [data_version pragma]
2674 ** </ul>
2675 */
2676 SQLITE_API int sqlite3_changes(sqlite3*);
2677 SQLITE_API sqlite3_int64 sqlite3_changes64(sqlite3*);
2678
2679 /*
2680 ** CAPI3REF: Total Number Of Rows Modified
2681 ** METHOD: sqlite3
2682 **
2683 ** ^These functions return the total number of rows inserted, modified or
2684 ** deleted by all [INSERT], [UPDATE] or [DELETE] statements completed
2685 ** since the database connection was opened, including those executed as
2686 ** part of trigger programs. The two functions are identical except for the
2687 ** type of the return value and that if the number of rows modified by the
2688 ** connection exceeds the maximum value supported by type "int", then
2689 ** the return value of sqlite3_total_changes() is undefined. ^Executing
2690 ** any other type of SQL statement does not affect the value returned by
2691 ** sqlite3_total_changes().
2692 **
2693 ** ^Changes made as part of [foreign key actions] are included in the
2694 ** count, but those made as part of REPLACE constraint resolution are
2695 ** not. ^Changes to a view that are intercepted by INSTEAD OF triggers
2696 ** are not counted.
2697 **
2698 ** The [sqlite3_total_changes(D)] interface only reports the number
2699 ** of rows that changed due to SQL statement run against database
2700 ** connection D. Any changes by other database connections are ignored.
2701 ** To detect changes against a database file from other database
2702 ** connections use the [PRAGMA data_version] command or the
2703 ** [SQLITE_FCNTL_DATA_VERSION] [file control].
2704 **
2705 ** If a separate thread makes changes on the same database connection
2706 ** while [sqlite3_total_changes()] is running then the value
2707 ** returned is unpredictable and not meaningful.
2708 **
2709 ** See also:
2710 ** <ul>
2711 ** <li> the [sqlite3_changes()] interface
2712 ** <li> the [count_changes pragma]
2713 ** <li> the [changes() SQL function]
2714 ** <li> the [data_version pragma]
2715 ** <li> the [SQLITE_FCNTL_DATA_VERSION] [file control]
2716 ** </ul>
2717 */
2718 SQLITE_API int sqlite3_total_changes(sqlite3*);
2719 SQLITE_API sqlite3_int64 sqlite3_total_changes64(sqlite3*);
2720
2721 /*
2722 ** CAPI3REF: Interrupt A Long-Running Query
2723 ** METHOD: sqlite3
2724 **
2725 ** ^This function causes any pending database operation to abort and
2726 ** return at its earliest opportunity. This routine is typically
2727 ** called in response to a user action such as pressing "Cancel"
2728 ** or Ctrl-C where the user wants a long query operation to halt
2729 ** immediately.
2730 **
2731 ** ^It is safe to call this routine from a thread different from the
2732 ** thread that is currently running the database operation. But it
2733 ** is not safe to call this routine with a [database connection] that
2734 ** is closed or might close before sqlite3_interrupt() returns.
2735 **
2736 ** ^If an SQL operation is very nearly finished at the time when
2737 ** sqlite3_interrupt() is called, then it might not have an opportunity
2738 ** to be interrupted and might continue to completion.
2739 **
2740 ** ^An SQL operation that is interrupted will return [SQLITE_INTERRUPT].
2741 ** ^If the interrupted SQL operation is an INSERT, UPDATE, or DELETE
2742 ** that is inside an explicit transaction, then the entire transaction
2743 ** will be rolled back automatically.
2744 **
2745 ** ^The sqlite3_interrupt(D) call is in effect until all currently running
2746 ** SQL statements on [database connection] D complete. ^Any new SQL statements
2747 ** that are started after the sqlite3_interrupt() call and before the
2748 ** running statement count reaches zero are interrupted as if they had been
2749 ** running prior to the sqlite3_interrupt() call. ^New SQL statements
2750 ** that are started after the running statement count reaches zero are
2751 ** not effected by the sqlite3_interrupt().
2752 ** ^A call to sqlite3_interrupt(D) that occurs when there are no running
2753 ** SQL statements is a no-op and has no effect on SQL statements
2754 ** that are started after the sqlite3_interrupt() call returns.
2755 **
2756 ** ^The [sqlite3_is_interrupted(D)] interface can be used to determine whether
2757 ** or not an interrupt is currently in effect for [database connection] D.
2758 ** It returns 1 if an interrupt is currently in effect, or 0 otherwise.
2759 */
2760 SQLITE_API void sqlite3_interrupt(sqlite3*);
2761 SQLITE_API int sqlite3_is_interrupted(sqlite3*);
2762
2763 /*
2764 ** CAPI3REF: Determine If An SQL Statement Is Complete
2765 **
2766 ** These routines are useful during command-line input to determine if the
2767 ** currently entered text seems to form a complete SQL statement or
2768 ** if additional input is needed before sending the text into
2769 ** SQLite for parsing. ^These routines return 1 if the input string
2770 ** appears to be a complete SQL statement. ^A statement is judged to be
2771 ** complete if it ends with a semicolon token and is not a prefix of a
2772 ** well-formed CREATE TRIGGER statement. ^Semicolons that are embedded within
2773 ** string literals or quoted identifier names or comments are not
2774 ** independent tokens (they are part of the token in which they are
2775 ** embedded) and thus do not count as a statement terminator. ^Whitespace
2776 ** and comments that follow the final semicolon are ignored.
2777 **
2778 ** ^These routines return 0 if the statement is incomplete. ^If a
2779 ** memory allocation fails, then SQLITE_NOMEM is returned.
2780 **
2781 ** ^These routines do not parse the SQL statements thus
2782 ** will not detect syntactically incorrect SQL.
2783 **
2784 ** ^(If SQLite has not been initialized using [sqlite3_initialize()] prior
2785 ** to invoking sqlite3_complete16() then sqlite3_initialize() is invoked
2786 ** automatically by sqlite3_complete16(). If that initialization fails,
2787 ** then the return value from sqlite3_complete16() will be non-zero
2788 ** regardless of whether or not the input SQL is complete.)^
2789 **
2790 ** The input to [sqlite3_complete()] must be a zero-terminated
2791 ** UTF-8 string.
2792 **
2793 ** The input to [sqlite3_complete16()] must be a zero-terminated
2794 ** UTF-16 string in native byte order.
2795 */
2796 SQLITE_API int sqlite3_complete(const char *sql);
2797 SQLITE_API int sqlite3_complete16(const void *sql);
2798
2799 /*
2800 ** CAPI3REF: Register A Callback To Handle SQLITE_BUSY Errors
2801 ** KEYWORDS: {busy-handler callback} {busy handler}
2802 ** METHOD: sqlite3
2803 **
2804 ** ^The sqlite3_busy_handler(D,X,P) routine sets a callback function X
2805 ** that might be invoked with argument P whenever
2806 ** an attempt is made to access a database table associated with
2807 ** [database connection] D when another thread
2808 ** or process has the table locked.
2809 ** The sqlite3_busy_handler() interface is used to implement
2810 ** [sqlite3_busy_timeout()] and [PRAGMA busy_timeout].
2811 **
2812 ** ^If the busy callback is NULL, then [SQLITE_BUSY]
2813 ** is returned immediately upon encountering the lock. ^If the busy callback
2814 ** is not NULL, then the callback might be invoked with two arguments.
2815 **
2816 ** ^The first argument to the busy handler is a copy of the void* pointer which
2817 ** is the third argument to sqlite3_busy_handler(). ^The second argument to
2818 ** the busy handler callback is the number of times that the busy handler has
2819 ** been invoked previously for the same locking event. ^If the
2820 ** busy callback returns 0, then no additional attempts are made to
2821 ** access the database and [SQLITE_BUSY] is returned
2822 ** to the application.
2823 ** ^If the callback returns non-zero, then another attempt
2824 ** is made to access the database and the cycle repeats.
2825 **
2826 ** The presence of a busy handler does not guarantee that it will be invoked
2827 ** when there is lock contention. ^If SQLite determines that invoking the busy
2828 ** handler could result in a deadlock, it will go ahead and return [SQLITE_BUSY]
2829 ** to the application instead of invoking the
2830 ** busy handler.
2831 ** Consider a scenario where one process is holding a read lock that
2832 ** it is trying to promote to a reserved lock and
2833 ** a second process is holding a reserved lock that it is trying
2834 ** to promote to an exclusive lock. The first process cannot proceed
2835 ** because it is blocked by the second and the second process cannot
2836 ** proceed because it is blocked by the first. If both processes
2837 ** invoke the busy handlers, neither will make any progress. Therefore,
2838 ** SQLite returns [SQLITE_BUSY] for the first process, hoping that this
2839 ** will induce the first process to release its read lock and allow
2840 ** the second process to proceed.
2841 **
2842 ** ^The default busy callback is NULL.
2843 **
2844 ** ^(There can only be a single busy handler defined for each
2845 ** [database connection]. Setting a new busy handler clears any
2846 ** previously set handler.)^ ^Note that calling [sqlite3_busy_timeout()]
2847 ** or evaluating [PRAGMA busy_timeout=N] will change the
2848 ** busy handler and thus clear any previously set busy handler.
2849 **
2850 ** The busy callback should not take any actions which modify the
2851 ** database connection that invoked the busy handler. In other words,
2852 ** the busy handler is not reentrant. Any such actions
2853 ** result in undefined behavior.
2854 **
2855 ** A busy handler must not close the database connection
2856 ** or [prepared statement] that invoked the busy handler.
2857 */
2858 SQLITE_API int sqlite3_busy_handler(sqlite3*,int(*)(void*,int),void*);
2859
2860 /*
2861 ** CAPI3REF: Set A Busy Timeout
2862 ** METHOD: sqlite3
2863 **
2864 ** ^This routine sets a [sqlite3_busy_handler | busy handler] that sleeps
2865 ** for a specified amount of time when a table is locked. ^The handler
2866 ** will sleep multiple times until at least "ms" milliseconds of sleeping
2867 ** have accumulated. ^After at least "ms" milliseconds of sleeping,
2868 ** the handler returns 0 which causes [sqlite3_step()] to return
2869 ** [SQLITE_BUSY].
2870 **
2871 ** ^Calling this routine with an argument less than or equal to zero
2872 ** turns off all busy handlers.
2873 **
2874 ** ^(There can only be a single busy handler for a particular
2875 ** [database connection] at any given moment. If another busy handler
2876 ** was defined (using [sqlite3_busy_handler()]) prior to calling
2877 ** this routine, that other busy handler is cleared.)^
2878 **
2879 ** See also: [PRAGMA busy_timeout]
2880 */
2881 SQLITE_API int sqlite3_busy_timeout(sqlite3*, int ms);
2882
2883 /*
2884 ** CAPI3REF: Convenience Routines For Running Queries
2885 ** METHOD: sqlite3
2886 **
2887 ** This is a legacy interface that is preserved for backwards compatibility.
2888 ** Use of this interface is not recommended.
2889 **
2890 ** Definition: A <b>result table</b> is memory data structure created by the
2891 ** [sqlite3_get_table()] interface. A result table records the
2892 ** complete query results from one or more queries.
2893 **
2894 ** The table conceptually has a number of rows and columns. But
2895 ** these numbers are not part of the result table itself. These
2896 ** numbers are obtained separately. Let N be the number of rows
2897 ** and M be the number of columns.
2898 **
2899 ** A result table is an array of pointers to zero-terminated UTF-8 strings.
2900 ** There are (N+1)*M elements in the array. The first M pointers point
2901 ** to zero-terminated strings that contain the names of the columns.
2902 ** The remaining entries all point to query results. NULL values result
2903 ** in NULL pointers. All other values are in their UTF-8 zero-terminated
2904 ** string representation as returned by [sqlite3_column_text()].
2905 **
2906 ** A result table might consist of one or more memory allocations.
2907 ** It is not safe to pass a result table directly to [sqlite3_free()].
2908 ** A result table should be deallocated using [sqlite3_free_table()].
2909 **
2910 ** ^(As an example of the result table format, suppose a query result
2911 ** is as follows:
2912 **
2913 ** <blockquote><pre>
2914 ** Name | Age
2915 ** -----------------------
2916 ** Alice | 43
2917 ** Bob | 28
2918 ** Cindy | 21
2919 ** </pre></blockquote>
2920 **
2921 ** There are two columns (M==2) and three rows (N==3). Thus the
2922 ** result table has 8 entries. Suppose the result table is stored
2923 ** in an array named azResult. Then azResult holds this content:
2924 **
2925 ** <blockquote><pre>
2926 ** azResult&#91;0] = "Name";
2927 ** azResult&#91;1] = "Age";
2928 ** azResult&#91;2] = "Alice";
2929 ** azResult&#91;3] = "43";
2930 ** azResult&#91;4] = "Bob";
2931 ** azResult&#91;5] = "28";
2932 ** azResult&#91;6] = "Cindy";
2933 ** azResult&#91;7] = "21";
2934 ** </pre></blockquote>)^
2935 **
2936 ** ^The sqlite3_get_table() function evaluates one or more
2937 ** semicolon-separated SQL statements in the zero-terminated UTF-8
2938 ** string of its 2nd parameter and returns a result table to the
2939 ** pointer given in its 3rd parameter.
2940 **
2941 ** After the application has finished with the result from sqlite3_get_table(),
2942 ** it must pass the result table pointer to sqlite3_free_table() in order to
2943 ** release the memory that was malloced. Because of the way the
2944 ** [sqlite3_malloc()] happens within sqlite3_get_table(), the calling
2945 ** function must not try to call [sqlite3_free()] directly. Only
2946 ** [sqlite3_free_table()] is able to release the memory properly and safely.
2947 **
2948 ** The sqlite3_get_table() interface is implemented as a wrapper around
2949 ** [sqlite3_exec()]. The sqlite3_get_table() routine does not have access
2950 ** to any internal data structures of SQLite. It uses only the public
2951 ** interface defined here. As a consequence, errors that occur in the
2952 ** wrapper layer outside of the internal [sqlite3_exec()] call are not
2953 ** reflected in subsequent calls to [sqlite3_errcode()] or
2954 ** [sqlite3_errmsg()].
2955 */
2956 SQLITE_API int sqlite3_get_table(
2957 sqlite3 *db, /* An open database */
2958 const char *zSql, /* SQL to be evaluated */
2959 char ***pazResult, /* Results of the query */
2960 int *pnRow, /* Number of result rows written here */
2961 int *pnColumn, /* Number of result columns written here */
2962 char **pzErrmsg /* Error msg written here */
2963 );
2964 SQLITE_API void sqlite3_free_table(char **result);
2965
2966 /*
2967 ** CAPI3REF: Formatted String Printing Functions
2968 **
2969 ** These routines are work-alikes of the "printf()" family of functions
2970 ** from the standard C library.
2971 ** These routines understand most of the common formatting options from
2972 ** the standard library printf()
2973 ** plus some additional non-standard formats ([%q], [%Q], [%w], and [%z]).
2974 ** See the [built-in printf()] documentation for details.
2975 **
2976 ** ^The sqlite3_mprintf() and sqlite3_vmprintf() routines write their
2977 ** results into memory obtained from [sqlite3_malloc64()].
2978 ** The strings returned by these two routines should be
2979 ** released by [sqlite3_free()]. ^Both routines return a
2980 ** NULL pointer if [sqlite3_malloc64()] is unable to allocate enough
2981 ** memory to hold the resulting string.
2982 **
2983 ** ^(The sqlite3_snprintf() routine is similar to "snprintf()" from
2984 ** the standard C library. The result is written into the
2985 ** buffer supplied as the second parameter whose size is given by
2986 ** the first parameter. Note that the order of the
2987 ** first two parameters is reversed from snprintf().)^ This is an
2988 ** historical accident that cannot be fixed without breaking
2989 ** backwards compatibility. ^(Note also that sqlite3_snprintf()
2990 ** returns a pointer to its buffer instead of the number of
2991 ** characters actually written into the buffer.)^ We admit that
2992 ** the number of characters written would be a more useful return
2993 ** value but we cannot change the implementation of sqlite3_snprintf()
2994 ** now without breaking compatibility.
2995 **
2996 ** ^As long as the buffer size is greater than zero, sqlite3_snprintf()
2997 ** guarantees that the buffer is always zero-terminated. ^The first
2998 ** parameter "n" is the total size of the buffer, including space for
2999 ** the zero terminator. So the longest string that can be completely
3000 ** written will be n-1 characters.
3001 **
3002 ** ^The sqlite3_vsnprintf() routine is a varargs version of sqlite3_snprintf().
3003 **
3004 ** See also: [built-in printf()], [printf() SQL function]
3005 */
3006 SQLITE_API char *sqlite3_mprintf(const char*,...);
3007 SQLITE_API char *sqlite3_vmprintf(const char*, va_list);
3008 SQLITE_API char *sqlite3_snprintf(int,char*,const char*, ...);
3009 SQLITE_API char *sqlite3_vsnprintf(int,char*,const char*, va_list);
3010
3011 /*
3012 ** CAPI3REF: Memory Allocation Subsystem
3013 **
3014 ** The SQLite core uses these three routines for all of its own
3015 ** internal memory allocation needs. "Core" in the previous sentence
3016 ** does not include operating-system specific [VFS] implementation. The
3017 ** Windows VFS uses native malloc() and free() for some operations.
3018 **
3019 ** ^The sqlite3_malloc() routine returns a pointer to a block
3020 ** of memory at least N bytes in length, where N is the parameter.
3021 ** ^If sqlite3_malloc() is unable to obtain sufficient free
3022 ** memory, it returns a NULL pointer. ^If the parameter N to
3023 ** sqlite3_malloc() is zero or negative then sqlite3_malloc() returns
3024 ** a NULL pointer.
3025 **
3026 ** ^The sqlite3_malloc64(N) routine works just like
3027 ** sqlite3_malloc(N) except that N is an unsigned 64-bit integer instead
3028 ** of a signed 32-bit integer.
3029 **
3030 ** ^Calling sqlite3_free() with a pointer previously returned
3031 ** by sqlite3_malloc() or sqlite3_realloc() releases that memory so
3032 ** that it might be reused. ^The sqlite3_free() routine is
3033 ** a no-op if is called with a NULL pointer. Passing a NULL pointer
3034 ** to sqlite3_free() is harmless. After being freed, memory
3035 ** should neither be read nor written. Even reading previously freed
3036 ** memory might result in a segmentation fault or other severe error.
3037 ** Memory corruption, a segmentation fault, or other severe error
3038 ** might result if sqlite3_free() is called with a non-NULL pointer that
3039 ** was not obtained from sqlite3_malloc() or sqlite3_realloc().
3040 **
3041 ** ^The sqlite3_realloc(X,N) interface attempts to resize a
3042 ** prior memory allocation X to be at least N bytes.
3043 ** ^If the X parameter to sqlite3_realloc(X,N)
3044 ** is a NULL pointer then its behavior is identical to calling
3045 ** sqlite3_malloc(N).
3046 ** ^If the N parameter to sqlite3_realloc(X,N) is zero or
3047 ** negative then the behavior is exactly the same as calling
3048 ** sqlite3_free(X).
3049 ** ^sqlite3_realloc(X,N) returns a pointer to a memory allocation
3050 ** of at least N bytes in size or NULL if insufficient memory is available.
3051 ** ^If M is the size of the prior allocation, then min(N,M) bytes
3052 ** of the prior allocation are copied into the beginning of buffer returned
3053 ** by sqlite3_realloc(X,N) and the prior allocation is freed.
3054 ** ^If sqlite3_realloc(X,N) returns NULL and N is positive, then the
3055 ** prior allocation is not freed.
3056 **
3057 ** ^The sqlite3_realloc64(X,N) interfaces works the same as
3058 ** sqlite3_realloc(X,N) except that N is a 64-bit unsigned integer instead
3059 ** of a 32-bit signed integer.
3060 **
3061 ** ^If X is a memory allocation previously obtained from sqlite3_malloc(),
3062 ** sqlite3_malloc64(), sqlite3_realloc(), or sqlite3_realloc64(), then
3063 ** sqlite3_msize(X) returns the size of that memory allocation in bytes.
3064 ** ^The value returned by sqlite3_msize(X) might be larger than the number
3065 ** of bytes requested when X was allocated. ^If X is a NULL pointer then
3066 ** sqlite3_msize(X) returns zero. If X points to something that is not
3067 ** the beginning of memory allocation, or if it points to a formerly
3068 ** valid memory allocation that has now been freed, then the behavior
3069 ** of sqlite3_msize(X) is undefined and possibly harmful.
3070 **
3071 ** ^The memory returned by sqlite3_malloc(), sqlite3_realloc(),
3072 ** sqlite3_malloc64(), and sqlite3_realloc64()
3073 ** is always aligned to at least an 8 byte boundary, or to a
3074 ** 4 byte boundary if the [SQLITE_4_BYTE_ALIGNED_MALLOC] compile-time
3075 ** option is used.
3076 **
3077 ** The pointer arguments to [sqlite3_free()] and [sqlite3_realloc()]
3078 ** must be either NULL or else pointers obtained from a prior
3079 ** invocation of [sqlite3_malloc()] or [sqlite3_realloc()] that have
3080 ** not yet been released.
3081 **
3082 ** The application must not read or write any part of
3083 ** a block of memory after it has been released using
3084 ** [sqlite3_free()] or [sqlite3_realloc()].
3085 */
3086 SQLITE_API void *sqlite3_malloc(int);
3087 SQLITE_API void *sqlite3_malloc64(sqlite3_uint64);
3088 SQLITE_API void *sqlite3_realloc(void*, int);
3089 SQLITE_API void *sqlite3_realloc64(void*, sqlite3_uint64);
3090 SQLITE_API void sqlite3_free(void*);
3091 SQLITE_API sqlite3_uint64 sqlite3_msize(void*);
3092
3093 /*
3094 ** CAPI3REF: Memory Allocator Statistics
3095 **
3096 ** SQLite provides these two interfaces for reporting on the status
3097 ** of the [sqlite3_malloc()], [sqlite3_free()], and [sqlite3_realloc()]
3098 ** routines, which form the built-in memory allocation subsystem.
3099 **
3100 ** ^The [sqlite3_memory_used()] routine returns the number of bytes
3101 ** of memory currently outstanding (malloced but not freed).
3102 ** ^The [sqlite3_memory_highwater()] routine returns the maximum
3103 ** value of [sqlite3_memory_used()] since the high-water mark
3104 ** was last reset. ^The values returned by [sqlite3_memory_used()] and
3105 ** [sqlite3_memory_highwater()] include any overhead
3106 ** added by SQLite in its implementation of [sqlite3_malloc()],
3107 ** but not overhead added by the any underlying system library
3108 ** routines that [sqlite3_malloc()] may call.
3109 **
3110 ** ^The memory high-water mark is reset to the current value of
3111 ** [sqlite3_memory_used()] if and only if the parameter to
3112 ** [sqlite3_memory_highwater()] is true. ^The value returned
3113 ** by [sqlite3_memory_highwater(1)] is the high-water mark
3114 ** prior to the reset.
3115 */
3116 SQLITE_API sqlite3_int64 sqlite3_memory_used(void);
3117 SQLITE_API sqlite3_int64 sqlite3_memory_highwater(int resetFlag);
3118
3119 /*
3120 ** CAPI3REF: Pseudo-Random Number Generator
3121 **
3122 ** SQLite contains a high-quality pseudo-random number generator (PRNG) used to
3123 ** select random [ROWID | ROWIDs] when inserting new records into a table that
3124 ** already uses the largest possible [ROWID]. The PRNG is also used for
3125 ** the built-in random() and randomblob() SQL functions. This interface allows
3126 ** applications to access the same PRNG for other purposes.
3127 **
3128 ** ^A call to this routine stores N bytes of randomness into buffer P.
3129 ** ^The P parameter can be a NULL pointer.
3130 **
3131 ** ^If this routine has not been previously called or if the previous
3132 ** call had N less than one or a NULL pointer for P, then the PRNG is
3133 ** seeded using randomness obtained from the xRandomness method of
3134 ** the default [sqlite3_vfs] object.
3135 ** ^If the previous call to this routine had an N of 1 or more and a
3136 ** non-NULL P then the pseudo-randomness is generated
3137 ** internally and without recourse to the [sqlite3_vfs] xRandomness
3138 ** method.
3139 */
3140 SQLITE_API void sqlite3_randomness(int N, void *P);
3141
3142 /*
3143 ** CAPI3REF: Compile-Time Authorization Callbacks
3144 ** METHOD: sqlite3
3145 ** KEYWORDS: {authorizer callback}
3146 **
3147 ** ^This routine registers an authorizer callback with a particular
3148 ** [database connection], supplied in the first argument.
3149 ** ^The authorizer callback is invoked as SQL statements are being compiled
3150 ** by [sqlite3_prepare()] or its variants [sqlite3_prepare_v2()],
3151 ** [sqlite3_prepare_v3()], [sqlite3_prepare16()], [sqlite3_prepare16_v2()],
3152 ** and [sqlite3_prepare16_v3()]. ^At various
3153 ** points during the compilation process, as logic is being created
3154 ** to perform various actions, the authorizer callback is invoked to
3155 ** see if those actions are allowed. ^The authorizer callback should
3156 ** return [SQLITE_OK] to allow the action, [SQLITE_IGNORE] to disallow the
3157 ** specific action but allow the SQL statement to continue to be
3158 ** compiled, or [SQLITE_DENY] to cause the entire SQL statement to be
3159 ** rejected with an error. ^If the authorizer callback returns
3160 ** any value other than [SQLITE_IGNORE], [SQLITE_OK], or [SQLITE_DENY]
3161 ** then the [sqlite3_prepare_v2()] or equivalent call that triggered
3162 ** the authorizer will fail with an error message.
3163 **
3164 ** When the callback returns [SQLITE_OK], that means the operation
3165 ** requested is ok. ^When the callback returns [SQLITE_DENY], the
3166 ** [sqlite3_prepare_v2()] or equivalent call that triggered the
3167 ** authorizer will fail with an error message explaining that
3168 ** access is denied.
3169 **
3170 ** ^The first parameter to the authorizer callback is a copy of the third
3171 ** parameter to the sqlite3_set_authorizer() interface. ^The second parameter
3172 ** to the callback is an integer [SQLITE_COPY | action code] that specifies
3173 ** the particular action to be authorized. ^The third through sixth parameters
3174 ** to the callback are either NULL pointers or zero-terminated strings
3175 ** that contain additional details about the action to be authorized.
3176 ** Applications must always be prepared to encounter a NULL pointer in any
3177 ** of the third through the sixth parameters of the authorization callback.
3178 **
3179 ** ^If the action code is [SQLITE_READ]
3180 ** and the callback returns [SQLITE_IGNORE] then the
3181 ** [prepared statement] statement is constructed to substitute
3182 ** a NULL value in place of the table column that would have
3183 ** been read if [SQLITE_OK] had been returned. The [SQLITE_IGNORE]
3184 ** return can be used to deny an untrusted user access to individual
3185 ** columns of a table.
3186 ** ^When a table is referenced by a [SELECT] but no column values are
3187 ** extracted from that table (for example in a query like
3188 ** "SELECT count(*) FROM tab") then the [SQLITE_READ] authorizer callback
3189 ** is invoked once for that table with a column name that is an empty string.
3190 ** ^If the action code is [SQLITE_DELETE] and the callback returns
3191 ** [SQLITE_IGNORE] then the [DELETE] operation proceeds but the
3192 ** [truncate optimization] is disabled and all rows are deleted individually.
3193 **
3194 ** An authorizer is used when [sqlite3_prepare | preparing]
3195 ** SQL statements from an untrusted source, to ensure that the SQL statements
3196 ** do not try to access data they are not allowed to see, or that they do not
3197 ** try to execute malicious statements that damage the database. For
3198 ** example, an application may allow a user to enter arbitrary
3199 ** SQL queries for evaluation by a database. But the application does
3200 ** not want the user to be able to make arbitrary changes to the
3201 ** database. An authorizer could then be put in place while the
3202 ** user-entered SQL is being [sqlite3_prepare | prepared] that
3203 ** disallows everything except [SELECT] statements.
3204 **
3205 ** Applications that need to process SQL from untrusted sources
3206 ** might also consider lowering resource limits using [sqlite3_limit()]
3207 ** and limiting database size using the [max_page_count] [PRAGMA]
3208 ** in addition to using an authorizer.
3209 **
3210 ** ^(Only a single authorizer can be in place on a database connection
3211 ** at a time. Each call to sqlite3_set_authorizer overrides the
3212 ** previous call.)^ ^Disable the authorizer by installing a NULL callback.
3213 ** The authorizer is disabled by default.
3214 **
3215 ** The authorizer callback must not do anything that will modify
3216 ** the database connection that invoked the authorizer callback.
3217 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
3218 ** database connections for the meaning of "modify" in this paragraph.
3219 **
3220 ** ^When [sqlite3_prepare_v2()] is used to prepare a statement, the
3221 ** statement might be re-prepared during [sqlite3_step()] due to a
3222 ** schema change. Hence, the application should ensure that the
3223 ** correct authorizer callback remains in place during the [sqlite3_step()].
3224 **
3225 ** ^Note that the authorizer callback is invoked only during
3226 ** [sqlite3_prepare()] or its variants. Authorization is not
3227 ** performed during statement evaluation in [sqlite3_step()], unless
3228 ** as stated in the previous paragraph, sqlite3_step() invokes
3229 ** sqlite3_prepare_v2() to reprepare a statement after a schema change.
3230 */
3231 SQLITE_API int sqlite3_set_authorizer(
3232 sqlite3*,
3233 int (*xAuth)(void*,int,const char*,const char*,const char*,const char*),
3234 void *pUserData
3235 );
3236
3237 /*
3238 ** CAPI3REF: Authorizer Return Codes
3239 **
3240 ** The [sqlite3_set_authorizer | authorizer callback function] must
3241 ** return either [SQLITE_OK] or one of these two constants in order
3242 ** to signal SQLite whether or not the action is permitted. See the
3243 ** [sqlite3_set_authorizer | authorizer documentation] for additional
3244 ** information.
3245 **
3246 ** Note that SQLITE_IGNORE is also used as a [conflict resolution mode]
3247 ** returned from the [sqlite3_vtab_on_conflict()] interface.
3248 */
3249 #define SQLITE_DENY 1 /* Abort the SQL statement with an error */
3250 #define SQLITE_IGNORE 2 /* Don't allow access, but don't generate an error */
3251
3252 /*
3253 ** CAPI3REF: Authorizer Action Codes
3254 **
3255 ** The [sqlite3_set_authorizer()] interface registers a callback function
3256 ** that is invoked to authorize certain SQL statement actions. The
3257 ** second parameter to the callback is an integer code that specifies
3258 ** what action is being authorized. These are the integer action codes that
3259 ** the authorizer callback may be passed.
3260 **
3261 ** These action code values signify what kind of operation is to be
3262 ** authorized. The 3rd and 4th parameters to the authorization
3263 ** callback function will be parameters or NULL depending on which of these
3264 ** codes is used as the second parameter. ^(The 5th parameter to the
3265 ** authorizer callback is the name of the database ("main", "temp",
3266 ** etc.) if applicable.)^ ^The 6th parameter to the authorizer callback
3267 ** is the name of the inner-most trigger or view that is responsible for
3268 ** the access attempt or NULL if this access attempt is directly from
3269 ** top-level SQL code.
3270 */
3271 /******************************************* 3rd ************ 4th ***********/
3272 #define SQLITE_CREATE_INDEX 1 /* Index Name Table Name */
3273 #define SQLITE_CREATE_TABLE 2 /* Table Name NULL */
3274 #define SQLITE_CREATE_TEMP_INDEX 3 /* Index Name Table Name */
3275 #define SQLITE_CREATE_TEMP_TABLE 4 /* Table Name NULL */
3276 #define SQLITE_CREATE_TEMP_TRIGGER 5 /* Trigger Name Table Name */
3277 #define SQLITE_CREATE_TEMP_VIEW 6 /* View Name NULL */
3278 #define SQLITE_CREATE_TRIGGER 7 /* Trigger Name Table Name */
3279 #define SQLITE_CREATE_VIEW 8 /* View Name NULL */
3280 #define SQLITE_DELETE 9 /* Table Name NULL */
3281 #define SQLITE_DROP_INDEX 10 /* Index Name Table Name */
3282 #define SQLITE_DROP_TABLE 11 /* Table Name NULL */
3283 #define SQLITE_DROP_TEMP_INDEX 12 /* Index Name Table Name */
3284 #define SQLITE_DROP_TEMP_TABLE 13 /* Table Name NULL */
3285 #define SQLITE_DROP_TEMP_TRIGGER 14 /* Trigger Name Table Name */
3286 #define SQLITE_DROP_TEMP_VIEW 15 /* View Name NULL */
3287 #define SQLITE_DROP_TRIGGER 16 /* Trigger Name Table Name */
3288 #define SQLITE_DROP_VIEW 17 /* View Name NULL */
3289 #define SQLITE_INSERT 18 /* Table Name NULL */
3290 #define SQLITE_PRAGMA 19 /* Pragma Name 1st arg or NULL */
3291 #define SQLITE_READ 20 /* Table Name Column Name */
3292 #define SQLITE_SELECT 21 /* NULL NULL */
3293 #define SQLITE_TRANSACTION 22 /* Operation NULL */
3294 #define SQLITE_UPDATE 23 /* Table Name Column Name */
3295 #define SQLITE_ATTACH 24 /* Filename NULL */
3296 #define SQLITE_DETACH 25 /* Database Name NULL */
3297 #define SQLITE_ALTER_TABLE 26 /* Database Name Table Name */
3298 #define SQLITE_REINDEX 27 /* Index Name NULL */
3299 #define SQLITE_ANALYZE 28 /* Table Name NULL */
3300 #define SQLITE_CREATE_VTABLE 29 /* Table Name Module Name */
3301 #define SQLITE_DROP_VTABLE 30 /* Table Name Module Name */
3302 #define SQLITE_FUNCTION 31 /* NULL Function Name */
3303 #define SQLITE_SAVEPOINT 32 /* Operation Savepoint Name */
3304 #define SQLITE_COPY 0 /* No longer used */
3305 #define SQLITE_RECURSIVE 33 /* NULL NULL */
3306
3307 /*
3308 ** CAPI3REF: Deprecated Tracing And Profiling Functions
3309 ** DEPRECATED
3310 **
3311 ** These routines are deprecated. Use the [sqlite3_trace_v2()] interface
3312 ** instead of the routines described here.
3313 **
3314 ** These routines register callback functions that can be used for
3315 ** tracing and profiling the execution of SQL statements.
3316 **
3317 ** ^The callback function registered by sqlite3_trace() is invoked at
3318 ** various times when an SQL statement is being run by [sqlite3_step()].
3319 ** ^The sqlite3_trace() callback is invoked with a UTF-8 rendering of the
3320 ** SQL statement text as the statement first begins executing.
3321 ** ^(Additional sqlite3_trace() callbacks might occur
3322 ** as each triggered subprogram is entered. The callbacks for triggers
3323 ** contain a UTF-8 SQL comment that identifies the trigger.)^
3324 **
3325 ** The [SQLITE_TRACE_SIZE_LIMIT] compile-time option can be used to limit
3326 ** the length of [bound parameter] expansion in the output of sqlite3_trace().
3327 **
3328 ** ^The callback function registered by sqlite3_profile() is invoked
3329 ** as each SQL statement finishes. ^The profile callback contains
3330 ** the original statement text and an estimate of wall-clock time
3331 ** of how long that statement took to run. ^The profile callback
3332 ** time is in units of nanoseconds, however the current implementation
3333 ** is only capable of millisecond resolution so the six least significant
3334 ** digits in the time are meaningless. Future versions of SQLite
3335 ** might provide greater resolution on the profiler callback. Invoking
3336 ** either [sqlite3_trace()] or [sqlite3_trace_v2()] will cancel the
3337 ** profile callback.
3338 */
3339 SQLITE_API SQLITE_DEPRECATED void *sqlite3_trace(sqlite3*,
3340 void(*xTrace)(void*,const char*), void*);
3341 SQLITE_API SQLITE_DEPRECATED void *sqlite3_profile(sqlite3*,
3342 void(*xProfile)(void*,const char*,sqlite3_uint64), void*);
3343
3344 /*
3345 ** CAPI3REF: SQL Trace Event Codes
3346 ** KEYWORDS: SQLITE_TRACE
3347 **
3348 ** These constants identify classes of events that can be monitored
3349 ** using the [sqlite3_trace_v2()] tracing logic. The M argument
3350 ** to [sqlite3_trace_v2(D,M,X,P)] is an OR-ed combination of one or more of
3351 ** the following constants. ^The first argument to the trace callback
3352 ** is one of the following constants.
3353 **
3354 ** New tracing constants may be added in future releases.
3355 **
3356 ** ^A trace callback has four arguments: xCallback(T,C,P,X).
3357 ** ^The T argument is one of the integer type codes above.
3358 ** ^The C argument is a copy of the context pointer passed in as the
3359 ** fourth argument to [sqlite3_trace_v2()].
3360 ** The P and X arguments are pointers whose meanings depend on T.
3361 **
3362 ** <dl>
3363 ** [[SQLITE_TRACE_STMT]] <dt>SQLITE_TRACE_STMT</dt>
3364 ** <dd>^An SQLITE_TRACE_STMT callback is invoked when a prepared statement
3365 ** first begins running and possibly at other times during the
3366 ** execution of the prepared statement, such as at the start of each
3367 ** trigger subprogram. ^The P argument is a pointer to the
3368 ** [prepared statement]. ^The X argument is a pointer to a string which
3369 ** is the unexpanded SQL text of the prepared statement or an SQL comment
3370 ** that indicates the invocation of a trigger. ^The callback can compute
3371 ** the same text that would have been returned by the legacy [sqlite3_trace()]
3372 ** interface by using the X argument when X begins with "--" and invoking
3373 ** [sqlite3_expanded_sql(P)] otherwise.
3374 **
3375 ** [[SQLITE_TRACE_PROFILE]] <dt>SQLITE_TRACE_PROFILE</dt>
3376 ** <dd>^An SQLITE_TRACE_PROFILE callback provides approximately the same
3377 ** information as is provided by the [sqlite3_profile()] callback.
3378 ** ^The P argument is a pointer to the [prepared statement] and the
3379 ** X argument points to a 64-bit integer which is approximately
3380 ** the number of nanoseconds that the prepared statement took to run.
3381 ** ^The SQLITE_TRACE_PROFILE callback is invoked when the statement finishes.
3382 **
3383 ** [[SQLITE_TRACE_ROW]] <dt>SQLITE_TRACE_ROW</dt>
3384 ** <dd>^An SQLITE_TRACE_ROW callback is invoked whenever a prepared
3385 ** statement generates a single row of result.
3386 ** ^The P argument is a pointer to the [prepared statement] and the
3387 ** X argument is unused.
3388 **
3389 ** [[SQLITE_TRACE_CLOSE]] <dt>SQLITE_TRACE_CLOSE</dt>
3390 ** <dd>^An SQLITE_TRACE_CLOSE callback is invoked when a database
3391 ** connection closes.
3392 ** ^The P argument is a pointer to the [database connection] object
3393 ** and the X argument is unused.
3394 ** </dl>
3395 */
3396 #define SQLITE_TRACE_STMT 0x01
3397 #define SQLITE_TRACE_PROFILE 0x02
3398 #define SQLITE_TRACE_ROW 0x04
3399 #define SQLITE_TRACE_CLOSE 0x08
3400
3401 /*
3402 ** CAPI3REF: SQL Trace Hook
3403 ** METHOD: sqlite3
3404 **
3405 ** ^The sqlite3_trace_v2(D,M,X,P) interface registers a trace callback
3406 ** function X against [database connection] D, using property mask M
3407 ** and context pointer P. ^If the X callback is
3408 ** NULL or if the M mask is zero, then tracing is disabled. The
3409 ** M argument should be the bitwise OR-ed combination of
3410 ** zero or more [SQLITE_TRACE] constants.
3411 **
3412 ** ^Each call to either sqlite3_trace(D,X,P) or sqlite3_trace_v2(D,M,X,P)
3413 ** overrides (cancels) all prior calls to sqlite3_trace(D,X,P) or
3414 ** sqlite3_trace_v2(D,M,X,P) for the [database connection] D. Each
3415 ** database connection may have at most one trace callback.
3416 **
3417 ** ^The X callback is invoked whenever any of the events identified by
3418 ** mask M occur. ^The integer return value from the callback is currently
3419 ** ignored, though this may change in future releases. Callback
3420 ** implementations should return zero to ensure future compatibility.
3421 **
3422 ** ^A trace callback is invoked with four arguments: callback(T,C,P,X).
3423 ** ^The T argument is one of the [SQLITE_TRACE]
3424 ** constants to indicate why the callback was invoked.
3425 ** ^The C argument is a copy of the context pointer.
3426 ** The P and X arguments are pointers whose meanings depend on T.
3427 **
3428 ** The sqlite3_trace_v2() interface is intended to replace the legacy
3429 ** interfaces [sqlite3_trace()] and [sqlite3_profile()], both of which
3430 ** are deprecated.
3431 */
3432 SQLITE_API int sqlite3_trace_v2(
3433 sqlite3*,
3434 unsigned uMask,
3435 int(*xCallback)(unsigned,void*,void*,void*),
3436 void *pCtx
3437 );
3438
3439 /*
3440 ** CAPI3REF: Query Progress Callbacks
3441 ** METHOD: sqlite3
3442 **
3443 ** ^The sqlite3_progress_handler(D,N,X,P) interface causes the callback
3444 ** function X to be invoked periodically during long running calls to
3445 ** [sqlite3_step()] and [sqlite3_prepare()] and similar for
3446 ** database connection D. An example use for this
3447 ** interface is to keep a GUI updated during a large query.
3448 **
3449 ** ^The parameter P is passed through as the only parameter to the
3450 ** callback function X. ^The parameter N is the approximate number of
3451 ** [virtual machine instructions] that are evaluated between successive
3452 ** invocations of the callback X. ^If N is less than one then the progress
3453 ** handler is disabled.
3454 **
3455 ** ^Only a single progress handler may be defined at one time per
3456 ** [database connection]; setting a new progress handler cancels the
3457 ** old one. ^Setting parameter X to NULL disables the progress handler.
3458 ** ^The progress handler is also disabled by setting N to a value less
3459 ** than 1.
3460 **
3461 ** ^If the progress callback returns non-zero, the operation is
3462 ** interrupted. This feature can be used to implement a
3463 ** "Cancel" button on a GUI progress dialog box.
3464 **
3465 ** The progress handler callback must not do anything that will modify
3466 ** the database connection that invoked the progress handler.
3467 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
3468 ** database connections for the meaning of "modify" in this paragraph.
3469 **
3470 ** The progress handler callback would originally only be invoked from the
3471 ** bytecode engine. It still might be invoked during [sqlite3_prepare()]
3472 ** and similar because those routines might force a reparse of the schema
3473 ** which involves running the bytecode engine. However, beginning with
3474 ** SQLite version 3.41.0, the progress handler callback might also be
3475 ** invoked directly from [sqlite3_prepare()] while analyzing and generating
3476 ** code for complex queries.
3477 */
3478 SQLITE_API void sqlite3_progress_handler(sqlite3*, int, int(*)(void*), void*);
3479
3480 /*
3481 ** CAPI3REF: Opening A New Database Connection
3482 ** CONSTRUCTOR: sqlite3
3483 **
3484 ** ^These routines open an SQLite database file as specified by the
3485 ** filename argument. ^The filename argument is interpreted as UTF-8 for
3486 ** sqlite3_open() and sqlite3_open_v2() and as UTF-16 in the native byte
3487 ** order for sqlite3_open16(). ^(A [database connection] handle is usually
3488 ** returned in *ppDb, even if an error occurs. The only exception is that
3489 ** if SQLite is unable to allocate memory to hold the [sqlite3] object,
3490 ** a NULL will be written into *ppDb instead of a pointer to the [sqlite3]
3491 ** object.)^ ^(If the database is opened (and/or created) successfully, then
3492 ** [SQLITE_OK] is returned. Otherwise an [error code] is returned.)^ ^The
3493 ** [sqlite3_errmsg()] or [sqlite3_errmsg16()] routines can be used to obtain
3494 ** an English language description of the error following a failure of any
3495 ** of the sqlite3_open() routines.
3496 **
3497 ** ^The default encoding will be UTF-8 for databases created using
3498 ** sqlite3_open() or sqlite3_open_v2(). ^The default encoding for databases
3499 ** created using sqlite3_open16() will be UTF-16 in the native byte order.
3500 **
3501 ** Whether or not an error occurs when it is opened, resources
3502 ** associated with the [database connection] handle should be released by
3503 ** passing it to [sqlite3_close()] when it is no longer required.
3504 **
3505 ** The sqlite3_open_v2() interface works like sqlite3_open()
3506 ** except that it accepts two additional parameters for additional control
3507 ** over the new database connection. ^(The flags parameter to
3508 ** sqlite3_open_v2() must include, at a minimum, one of the following
3509 ** three flag combinations:)^
3510 **
3511 ** <dl>
3512 ** ^(<dt>[SQLITE_OPEN_READONLY]</dt>
3513 ** <dd>The database is opened in read-only mode. If the database does
3514 ** not already exist, an error is returned.</dd>)^
3515 **
3516 ** ^(<dt>[SQLITE_OPEN_READWRITE]</dt>
3517 ** <dd>The database is opened for reading and writing if possible, or
3518 ** reading only if the file is write protected by the operating
3519 ** system. In either case the database must already exist, otherwise
3520 ** an error is returned. For historical reasons, if opening in
3521 ** read-write mode fails due to OS-level permissions, an attempt is
3522 ** made to open it in read-only mode. [sqlite3_db_readonly()] can be
3523 ** used to determine whether the database is actually
3524 ** read-write.</dd>)^
3525 **
3526 ** ^(<dt>[SQLITE_OPEN_READWRITE] | [SQLITE_OPEN_CREATE]</dt>
3527 ** <dd>The database is opened for reading and writing, and is created if
3528 ** it does not already exist. This is the behavior that is always used for
3529 ** sqlite3_open() and sqlite3_open16().</dd>)^
3530 ** </dl>
3531 **
3532 ** In addition to the required flags, the following optional flags are
3533 ** also supported:
3534 **
3535 ** <dl>
3536 ** ^(<dt>[SQLITE_OPEN_URI]</dt>
3537 ** <dd>The filename can be interpreted as a URI if this flag is set.</dd>)^
3538 **
3539 ** ^(<dt>[SQLITE_OPEN_MEMORY]</dt>
3540 ** <dd>The database will be opened as an in-memory database. The database
3541 ** is named by the "filename" argument for the purposes of cache-sharing,
3542 ** if shared cache mode is enabled, but the "filename" is otherwise ignored.
3543 ** </dd>)^
3544 **
3545 ** ^(<dt>[SQLITE_OPEN_NOMUTEX]</dt>
3546 ** <dd>The new database connection will use the "multi-thread"
3547 ** [threading mode].)^ This means that separate threads are allowed
3548 ** to use SQLite at the same time, as long as each thread is using
3549 ** a different [database connection].
3550 **
3551 ** ^(<dt>[SQLITE_OPEN_FULLMUTEX]</dt>
3552 ** <dd>The new database connection will use the "serialized"
3553 ** [threading mode].)^ This means the multiple threads can safely
3554 ** attempt to use the same database connection at the same time.
3555 ** (Mutexes will block any actual concurrency, but in this mode
3556 ** there is no harm in trying.)
3557 **
3558 ** ^(<dt>[SQLITE_OPEN_SHAREDCACHE]</dt>
3559 ** <dd>The database is opened [shared cache] enabled, overriding
3560 ** the default shared cache setting provided by
3561 ** [sqlite3_enable_shared_cache()].)^
3562 ** The [use of shared cache mode is discouraged] and hence shared cache
3563 ** capabilities may be omitted from many builds of SQLite. In such cases,
3564 ** this option is a no-op.
3565 **
3566 ** ^(<dt>[SQLITE_OPEN_PRIVATECACHE]</dt>
3567 ** <dd>The database is opened [shared cache] disabled, overriding
3568 ** the default shared cache setting provided by
3569 ** [sqlite3_enable_shared_cache()].)^
3570 **
3571 ** [[OPEN_EXRESCODE]] ^(<dt>[SQLITE_OPEN_EXRESCODE]</dt>
3572 ** <dd>The database connection comes up in "extended result code mode".
3573 ** In other words, the database behaves has if
3574 ** [sqlite3_extended_result_codes(db,1)] where called on the database
3575 ** connection as soon as the connection is created. In addition to setting
3576 ** the extended result code mode, this flag also causes [sqlite3_open_v2()]
3577 ** to return an extended result code.</dd>
3578 **
3579 ** [[OPEN_NOFOLLOW]] ^(<dt>[SQLITE_OPEN_NOFOLLOW]</dt>
3580 ** <dd>The database filename is not allowed to contain a symbolic link</dd>
3581 ** </dl>)^
3582 **
3583 ** If the 3rd parameter to sqlite3_open_v2() is not one of the
3584 ** required combinations shown above optionally combined with other
3585 ** [SQLITE_OPEN_READONLY | SQLITE_OPEN_* bits]
3586 ** then the behavior is undefined. Historic versions of SQLite
3587 ** have silently ignored surplus bits in the flags parameter to
3588 ** sqlite3_open_v2(), however that behavior might not be carried through
3589 ** into future versions of SQLite and so applications should not rely
3590 ** upon it. Note in particular that the SQLITE_OPEN_EXCLUSIVE flag is a no-op
3591 ** for sqlite3_open_v2(). The SQLITE_OPEN_EXCLUSIVE does *not* cause
3592 ** the open to fail if the database already exists. The SQLITE_OPEN_EXCLUSIVE
3593 ** flag is intended for use by the [sqlite3_vfs|VFS interface] only, and not
3594 ** by sqlite3_open_v2().
3595 **
3596 ** ^The fourth parameter to sqlite3_open_v2() is the name of the
3597 ** [sqlite3_vfs] object that defines the operating system interface that
3598 ** the new database connection should use. ^If the fourth parameter is
3599 ** a NULL pointer then the default [sqlite3_vfs] object is used.
3600 **
3601 ** ^If the filename is ":memory:", then a private, temporary in-memory database
3602 ** is created for the connection. ^This in-memory database will vanish when
3603 ** the database connection is closed. Future versions of SQLite might
3604 ** make use of additional special filenames that begin with the ":" character.
3605 ** It is recommended that when a database filename actually does begin with
3606 ** a ":" character you should prefix the filename with a pathname such as
3607 ** "./" to avoid ambiguity.
3608 **
3609 ** ^If the filename is an empty string, then a private, temporary
3610 ** on-disk database will be created. ^This private database will be
3611 ** automatically deleted as soon as the database connection is closed.
3612 **
3613 ** [[URI filenames in sqlite3_open()]] <h3>URI Filenames</h3>
3614 **
3615 ** ^If [URI filename] interpretation is enabled, and the filename argument
3616 ** begins with "file:", then the filename is interpreted as a URI. ^URI
3617 ** filename interpretation is enabled if the [SQLITE_OPEN_URI] flag is
3618 ** set in the third argument to sqlite3_open_v2(), or if it has
3619 ** been enabled globally using the [SQLITE_CONFIG_URI] option with the
3620 ** [sqlite3_config()] method or by the [SQLITE_USE_URI] compile-time option.
3621 ** URI filename interpretation is turned off
3622 ** by default, but future releases of SQLite might enable URI filename
3623 ** interpretation by default. See "[URI filenames]" for additional
3624 ** information.
3625 **
3626 ** URI filenames are parsed according to RFC 3986. ^If the URI contains an
3627 ** authority, then it must be either an empty string or the string
3628 ** "localhost". ^If the authority is not an empty string or "localhost", an
3629 ** error is returned to the caller. ^The fragment component of a URI, if
3630 ** present, is ignored.
3631 **
3632 ** ^SQLite uses the path component of the URI as the name of the disk file
3633 ** which contains the database. ^If the path begins with a '/' character,
3634 ** then it is interpreted as an absolute path. ^If the path does not begin
3635 ** with a '/' (meaning that the authority section is omitted from the URI)
3636 ** then the path is interpreted as a relative path.
3637 ** ^(On windows, the first component of an absolute path
3638 ** is a drive specification (e.g. "C:").)^
3639 **
3640 ** [[core URI query parameters]]
3641 ** The query component of a URI may contain parameters that are interpreted
3642 ** either by SQLite itself, or by a [VFS | custom VFS implementation].
3643 ** SQLite and its built-in [VFSes] interpret the
3644 ** following query parameters:
3645 **
3646 ** <ul>
3647 ** <li> <b>vfs</b>: ^The "vfs" parameter may be used to specify the name of
3648 ** a VFS object that provides the operating system interface that should
3649 ** be used to access the database file on disk. ^If this option is set to
3650 ** an empty string the default VFS object is used. ^Specifying an unknown
3651 ** VFS is an error. ^If sqlite3_open_v2() is used and the vfs option is
3652 ** present, then the VFS specified by the option takes precedence over
3653 ** the value passed as the fourth parameter to sqlite3_open_v2().
3654 **
3655 ** <li> <b>mode</b>: ^(The mode parameter may be set to either "ro", "rw",
3656 ** "rwc", or "memory". Attempting to set it to any other value is
3657 ** an error)^.
3658 ** ^If "ro" is specified, then the database is opened for read-only
3659 ** access, just as if the [SQLITE_OPEN_READONLY] flag had been set in the
3660 ** third argument to sqlite3_open_v2(). ^If the mode option is set to
3661 ** "rw", then the database is opened for read-write (but not create)
3662 ** access, as if SQLITE_OPEN_READWRITE (but not SQLITE_OPEN_CREATE) had
3663 ** been set. ^Value "rwc" is equivalent to setting both
3664 ** SQLITE_OPEN_READWRITE and SQLITE_OPEN_CREATE. ^If the mode option is
3665 ** set to "memory" then a pure [in-memory database] that never reads
3666 ** or writes from disk is used. ^It is an error to specify a value for
3667 ** the mode parameter that is less restrictive than that specified by
3668 ** the flags passed in the third parameter to sqlite3_open_v2().
3669 **
3670 ** <li> <b>cache</b>: ^The cache parameter may be set to either "shared" or
3671 ** "private". ^Setting it to "shared" is equivalent to setting the
3672 ** SQLITE_OPEN_SHAREDCACHE bit in the flags argument passed to
3673 ** sqlite3_open_v2(). ^Setting the cache parameter to "private" is
3674 ** equivalent to setting the SQLITE_OPEN_PRIVATECACHE bit.
3675 ** ^If sqlite3_open_v2() is used and the "cache" parameter is present in
3676 ** a URI filename, its value overrides any behavior requested by setting
3677 ** SQLITE_OPEN_PRIVATECACHE or SQLITE_OPEN_SHAREDCACHE flag.
3678 **
3679 ** <li> <b>psow</b>: ^The psow parameter indicates whether or not the
3680 ** [powersafe overwrite] property does or does not apply to the
3681 ** storage media on which the database file resides.
3682 **
3683 ** <li> <b>nolock</b>: ^The nolock parameter is a boolean query parameter
3684 ** which if set disables file locking in rollback journal modes. This
3685 ** is useful for accessing a database on a filesystem that does not
3686 ** support locking. Caution: Database corruption might result if two
3687 ** or more processes write to the same database and any one of those
3688 ** processes uses nolock=1.
3689 **
3690 ** <li> <b>immutable</b>: ^The immutable parameter is a boolean query
3691 ** parameter that indicates that the database file is stored on
3692 ** read-only media. ^When immutable is set, SQLite assumes that the
3693 ** database file cannot be changed, even by a process with higher
3694 ** privilege, and so the database is opened read-only and all locking
3695 ** and change detection is disabled. Caution: Setting the immutable
3696 ** property on a database file that does in fact change can result
3697 ** in incorrect query results and/or [SQLITE_CORRUPT] errors.
3698 ** See also: [SQLITE_IOCAP_IMMUTABLE].
3699 **
3700 ** </ul>
3701 **
3702 ** ^Specifying an unknown parameter in the query component of a URI is not an
3703 ** error. Future versions of SQLite might understand additional query
3704 ** parameters. See "[query parameters with special meaning to SQLite]" for
3705 ** additional information.
3706 **
3707 ** [[URI filename examples]] <h3>URI filename examples</h3>
3708 **
3709 ** <table border="1" align=center cellpadding=5>
3710 ** <tr><th> URI filenames <th> Results
3711 ** <tr><td> file:data.db <td>
3712 ** Open the file "data.db" in the current directory.
3713 ** <tr><td> file:/home/fred/data.db<br>
3714 ** file:///home/fred/data.db <br>
3715 ** file://localhost/home/fred/data.db <br> <td>
3716 ** Open the database file "/home/fred/data.db".
3717 ** <tr><td> file://darkstar/home/fred/data.db <td>
3718 ** An error. "darkstar" is not a recognized authority.
3719 ** <tr><td style="white-space:nowrap">
3720 ** file:///C:/Documents%20and%20Settings/fred/Desktop/data.db
3721 ** <td> Windows only: Open the file "data.db" on fred's desktop on drive
3722 ** C:. Note that the %20 escaping in this example is not strictly
3723 ** necessary - space characters can be used literally
3724 ** in URI filenames.
3725 ** <tr><td> file:data.db?mode=ro&cache=private <td>
3726 ** Open file "data.db" in the current directory for read-only access.
3727 ** Regardless of whether or not shared-cache mode is enabled by
3728 ** default, use a private cache.
3729 ** <tr><td> file:/home/fred/data.db?vfs=unix-dotfile <td>
3730 ** Open file "/home/fred/data.db". Use the special VFS "unix-dotfile"
3731 ** that uses dot-files in place of posix advisory locking.
3732 ** <tr><td> file:data.db?mode=readonly <td>
3733 ** An error. "readonly" is not a valid option for the "mode" parameter.
3734 ** Use "ro" instead: "file:data.db?mode=ro".
3735 ** </table>
3736 **
3737 ** ^URI hexadecimal escape sequences (%HH) are supported within the path and
3738 ** query components of a URI. A hexadecimal escape sequence consists of a
3739 ** percent sign - "%" - followed by exactly two hexadecimal digits
3740 ** specifying an octet value. ^Before the path or query components of a
3741 ** URI filename are interpreted, they are encoded using UTF-8 and all
3742 ** hexadecimal escape sequences replaced by a single byte containing the
3743 ** corresponding octet. If this process generates an invalid UTF-8 encoding,
3744 ** the results are undefined.
3745 **
3746 ** <b>Note to Windows users:</b> The encoding used for the filename argument
3747 ** of sqlite3_open() and sqlite3_open_v2() must be UTF-8, not whatever
3748 ** codepage is currently defined. Filenames containing international
3749 ** characters must be converted to UTF-8 prior to passing them into
3750 ** sqlite3_open() or sqlite3_open_v2().
3751 **
3752 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set
3753 ** prior to calling sqlite3_open() or sqlite3_open_v2(). Otherwise, various
3754 ** features that require the use of temporary files may fail.
3755 **
3756 ** See also: [sqlite3_temp_directory]
3757 */
3758 SQLITE_API int sqlite3_open(
3759 const char *filename, /* Database filename (UTF-8) */
3760 sqlite3 **ppDb /* OUT: SQLite db handle */
3761 );
3762 SQLITE_API int sqlite3_open16(
3763 const void *filename, /* Database filename (UTF-16) */
3764 sqlite3 **ppDb /* OUT: SQLite db handle */
3765 );
3766 SQLITE_API int sqlite3_open_v2(
3767 const char *filename, /* Database filename (UTF-8) */
3768 sqlite3 **ppDb, /* OUT: SQLite db handle */
3769 int flags, /* Flags */
3770 const char *zVfs /* Name of VFS module to use */
3771 );
3772
3773 /*
3774 ** CAPI3REF: Obtain Values For URI Parameters
3775 **
3776 ** These are utility routines, useful to [VFS|custom VFS implementations],
3777 ** that check if a database file was a URI that contained a specific query
3778 ** parameter, and if so obtains the value of that query parameter.
3779 **
3780 ** The first parameter to these interfaces (hereafter referred to
3781 ** as F) must be one of:
3782 ** <ul>
3783 ** <li> A database filename pointer created by the SQLite core and
3784 ** passed into the xOpen() method of a VFS implementation, or
3785 ** <li> A filename obtained from [sqlite3_db_filename()], or
3786 ** <li> A new filename constructed using [sqlite3_create_filename()].
3787 ** </ul>
3788 ** If the F parameter is not one of the above, then the behavior is
3789 ** undefined and probably undesirable. Older versions of SQLite were
3790 ** more tolerant of invalid F parameters than newer versions.
3791 **
3792 ** If F is a suitable filename (as described in the previous paragraph)
3793 ** and if P is the name of the query parameter, then
3794 ** sqlite3_uri_parameter(F,P) returns the value of the P
3795 ** parameter if it exists or a NULL pointer if P does not appear as a
3796 ** query parameter on F. If P is a query parameter of F and it
3797 ** has no explicit value, then sqlite3_uri_parameter(F,P) returns
3798 ** a pointer to an empty string.
3799 **
3800 ** The sqlite3_uri_boolean(F,P,B) routine assumes that P is a boolean
3801 ** parameter and returns true (1) or false (0) according to the value
3802 ** of P. The sqlite3_uri_boolean(F,P,B) routine returns true (1) if the
3803 ** value of query parameter P is one of "yes", "true", or "on" in any
3804 ** case or if the value begins with a non-zero number. The
3805 ** sqlite3_uri_boolean(F,P,B) routines returns false (0) if the value of
3806 ** query parameter P is one of "no", "false", or "off" in any case or
3807 ** if the value begins with a numeric zero. If P is not a query
3808 ** parameter on F or if the value of P does not match any of the
3809 ** above, then sqlite3_uri_boolean(F,P,B) returns (B!=0).
3810 **
3811 ** The sqlite3_uri_int64(F,P,D) routine converts the value of P into a
3812 ** 64-bit signed integer and returns that integer, or D if P does not
3813 ** exist. If the value of P is something other than an integer, then
3814 ** zero is returned.
3815 **
3816 ** The sqlite3_uri_key(F,N) returns a pointer to the name (not
3817 ** the value) of the N-th query parameter for filename F, or a NULL
3818 ** pointer if N is less than zero or greater than the number of query
3819 ** parameters minus 1. The N value is zero-based so N should be 0 to obtain
3820 ** the name of the first query parameter, 1 for the second parameter, and
3821 ** so forth.
3822 **
3823 ** If F is a NULL pointer, then sqlite3_uri_parameter(F,P) returns NULL and
3824 ** sqlite3_uri_boolean(F,P,B) returns B. If F is not a NULL pointer and
3825 ** is not a database file pathname pointer that the SQLite core passed
3826 ** into the xOpen VFS method, then the behavior of this routine is undefined
3827 ** and probably undesirable.
3828 **
3829 ** Beginning with SQLite [version 3.31.0] ([dateof:3.31.0]) the input F
3830 ** parameter can also be the name of a rollback journal file or WAL file
3831 ** in addition to the main database file. Prior to version 3.31.0, these
3832 ** routines would only work if F was the name of the main database file.
3833 ** When the F parameter is the name of the rollback journal or WAL file,
3834 ** it has access to all the same query parameters as were found on the
3835 ** main database file.
3836 **
3837 ** See the [URI filename] documentation for additional information.
3838 */
3839 SQLITE_API const char *sqlite3_uri_parameter(sqlite3_filename z, const char *zParam);
3840 SQLITE_API int sqlite3_uri_boolean(sqlite3_filename z, const char *zParam, int bDefault);
3841 SQLITE_API sqlite3_int64 sqlite3_uri_int64(sqlite3_filename, const char*, sqlite3_int64);
3842 SQLITE_API const char *sqlite3_uri_key(sqlite3_filename z, int N);
3843
3844 /*
3845 ** CAPI3REF: Translate filenames
3846 **
3847 ** These routines are available to [VFS|custom VFS implementations] for
3848 ** translating filenames between the main database file, the journal file,
3849 ** and the WAL file.
3850 **
3851 ** If F is the name of an sqlite database file, journal file, or WAL file
3852 ** passed by the SQLite core into the VFS, then sqlite3_filename_database(F)
3853 ** returns the name of the corresponding database file.
3854 **
3855 ** If F is the name of an sqlite database file, journal file, or WAL file
3856 ** passed by the SQLite core into the VFS, or if F is a database filename
3857 ** obtained from [sqlite3_db_filename()], then sqlite3_filename_journal(F)
3858 ** returns the name of the corresponding rollback journal file.
3859 **
3860 ** If F is the name of an sqlite database file, journal file, or WAL file
3861 ** that was passed by the SQLite core into the VFS, or if F is a database
3862 ** filename obtained from [sqlite3_db_filename()], then
3863 ** sqlite3_filename_wal(F) returns the name of the corresponding
3864 ** WAL file.
3865 **
3866 ** In all of the above, if F is not the name of a database, journal or WAL
3867 ** filename passed into the VFS from the SQLite core and F is not the
3868 ** return value from [sqlite3_db_filename()], then the result is
3869 ** undefined and is likely a memory access violation.
3870 */
3871 SQLITE_API const char *sqlite3_filename_database(sqlite3_filename);
3872 SQLITE_API const char *sqlite3_filename_journal(sqlite3_filename);
3873 SQLITE_API const char *sqlite3_filename_wal(sqlite3_filename);
3874
3875 /*
3876 ** CAPI3REF: Database File Corresponding To A Journal
3877 **
3878 ** ^If X is the name of a rollback or WAL-mode journal file that is
3879 ** passed into the xOpen method of [sqlite3_vfs], then
3880 ** sqlite3_database_file_object(X) returns a pointer to the [sqlite3_file]
3881 ** object that represents the main database file.
3882 **
3883 ** This routine is intended for use in custom [VFS] implementations
3884 ** only. It is not a general-purpose interface.
3885 ** The argument sqlite3_file_object(X) must be a filename pointer that
3886 ** has been passed into [sqlite3_vfs].xOpen method where the
3887 ** flags parameter to xOpen contains one of the bits
3888 ** [SQLITE_OPEN_MAIN_JOURNAL] or [SQLITE_OPEN_WAL]. Any other use
3889 ** of this routine results in undefined and probably undesirable
3890 ** behavior.
3891 */
3892 SQLITE_API sqlite3_file *sqlite3_database_file_object(const char*);
3893
3894 /*
3895 ** CAPI3REF: Create and Destroy VFS Filenames
3896 **
3897 ** These interfaces are provided for use by [VFS shim] implementations and
3898 ** are not useful outside of that context.
3899 **
3900 ** The sqlite3_create_filename(D,J,W,N,P) allocates memory to hold a version of
3901 ** database filename D with corresponding journal file J and WAL file W and
3902 ** with N URI parameters key/values pairs in the array P. The result from
3903 ** sqlite3_create_filename(D,J,W,N,P) is a pointer to a database filename that
3904 ** is safe to pass to routines like:
3905 ** <ul>
3906 ** <li> [sqlite3_uri_parameter()],
3907 ** <li> [sqlite3_uri_boolean()],
3908 ** <li> [sqlite3_uri_int64()],
3909 ** <li> [sqlite3_uri_key()],
3910 ** <li> [sqlite3_filename_database()],
3911 ** <li> [sqlite3_filename_journal()], or
3912 ** <li> [sqlite3_filename_wal()].
3913 ** </ul>
3914 ** If a memory allocation error occurs, sqlite3_create_filename() might
3915 ** return a NULL pointer. The memory obtained from sqlite3_create_filename(X)
3916 ** must be released by a corresponding call to sqlite3_free_filename(Y).
3917 **
3918 ** The P parameter in sqlite3_create_filename(D,J,W,N,P) should be an array
3919 ** of 2*N pointers to strings. Each pair of pointers in this array corresponds
3920 ** to a key and value for a query parameter. The P parameter may be a NULL
3921 ** pointer if N is zero. None of the 2*N pointers in the P array may be
3922 ** NULL pointers and key pointers should not be empty strings.
3923 ** None of the D, J, or W parameters to sqlite3_create_filename(D,J,W,N,P) may
3924 ** be NULL pointers, though they can be empty strings.
3925 **
3926 ** The sqlite3_free_filename(Y) routine releases a memory allocation
3927 ** previously obtained from sqlite3_create_filename(). Invoking
3928 ** sqlite3_free_filename(Y) where Y is a NULL pointer is a harmless no-op.
3929 **
3930 ** If the Y parameter to sqlite3_free_filename(Y) is anything other
3931 ** than a NULL pointer or a pointer previously acquired from
3932 ** sqlite3_create_filename(), then bad things such as heap
3933 ** corruption or segfaults may occur. The value Y should not be
3934 ** used again after sqlite3_free_filename(Y) has been called. This means
3935 ** that if the [sqlite3_vfs.xOpen()] method of a VFS has been called using Y,
3936 ** then the corresponding [sqlite3_module.xClose() method should also be
3937 ** invoked prior to calling sqlite3_free_filename(Y).
3938 */
3939 SQLITE_API sqlite3_filename sqlite3_create_filename(
3940 const char *zDatabase,
3941 const char *zJournal,
3942 const char *zWal,
3943 int nParam,
3944 const char **azParam
3945 );
3946 SQLITE_API void sqlite3_free_filename(sqlite3_filename);
3947
3948 /*
3949 ** CAPI3REF: Error Codes And Messages
3950 ** METHOD: sqlite3
3951 **
3952 ** ^If the most recent sqlite3_* API call associated with
3953 ** [database connection] D failed, then the sqlite3_errcode(D) interface
3954 ** returns the numeric [result code] or [extended result code] for that
3955 ** API call.
3956 ** ^The sqlite3_extended_errcode()
3957 ** interface is the same except that it always returns the
3958 ** [extended result code] even when extended result codes are
3959 ** disabled.
3960 **
3961 ** The values returned by sqlite3_errcode() and/or
3962 ** sqlite3_extended_errcode() might change with each API call.
3963 ** Except, there are some interfaces that are guaranteed to never
3964 ** change the value of the error code. The error-code preserving
3965 ** interfaces include the following:
3966 **
3967 ** <ul>
3968 ** <li> sqlite3_errcode()
3969 ** <li> sqlite3_extended_errcode()
3970 ** <li> sqlite3_errmsg()
3971 ** <li> sqlite3_errmsg16()
3972 ** <li> sqlite3_error_offset()
3973 ** </ul>
3974 **
3975 ** ^The sqlite3_errmsg() and sqlite3_errmsg16() return English-language
3976 ** text that describes the error, as either UTF-8 or UTF-16 respectively,
3977 ** or NULL if no error message is available.
3978 ** (See how SQLite handles [invalid UTF] for exceptions to this rule.)
3979 ** ^(Memory to hold the error message string is managed internally.
3980 ** The application does not need to worry about freeing the result.
3981 ** However, the error string might be overwritten or deallocated by
3982 ** subsequent calls to other SQLite interface functions.)^
3983 **
3984 ** ^The sqlite3_errstr(E) interface returns the English-language text
3985 ** that describes the [result code] E, as UTF-8, or NULL if E is not an
3986 ** result code for which a text error message is available.
3987 ** ^(Memory to hold the error message string is managed internally
3988 ** and must not be freed by the application)^.
3989 **
3990 ** ^If the most recent error references a specific token in the input
3991 ** SQL, the sqlite3_error_offset() interface returns the byte offset
3992 ** of the start of that token. ^The byte offset returned by
3993 ** sqlite3_error_offset() assumes that the input SQL is UTF8.
3994 ** ^If the most recent error does not reference a specific token in the input
3995 ** SQL, then the sqlite3_error_offset() function returns -1.
3996 **
3997 ** When the serialized [threading mode] is in use, it might be the
3998 ** case that a second error occurs on a separate thread in between
3999 ** the time of the first error and the call to these interfaces.
4000 ** When that happens, the second error will be reported since these
4001 ** interfaces always report the most recent result. To avoid
4002 ** this, each thread can obtain exclusive use of the [database connection] D
4003 ** by invoking [sqlite3_mutex_enter]([sqlite3_db_mutex](D)) before beginning
4004 ** to use D and invoking [sqlite3_mutex_leave]([sqlite3_db_mutex](D)) after
4005 ** all calls to the interfaces listed here are completed.
4006 **
4007 ** If an interface fails with SQLITE_MISUSE, that means the interface
4008 ** was invoked incorrectly by the application. In that case, the
4009 ** error code and message may or may not be set.
4010 */
4011 SQLITE_API int sqlite3_errcode(sqlite3 *db);
4012 SQLITE_API int sqlite3_extended_errcode(sqlite3 *db);
4013 SQLITE_API const char *sqlite3_errmsg(sqlite3*);
4014 SQLITE_API const void *sqlite3_errmsg16(sqlite3*);
4015 SQLITE_API const char *sqlite3_errstr(int);
4016 SQLITE_API int sqlite3_error_offset(sqlite3 *db);
4017
4018 /*
4019 ** CAPI3REF: Prepared Statement Object
4020 ** KEYWORDS: {prepared statement} {prepared statements}
4021 **
4022 ** An instance of this object represents a single SQL statement that
4023 ** has been compiled into binary form and is ready to be evaluated.
4024 **
4025 ** Think of each SQL statement as a separate computer program. The
4026 ** original SQL text is source code. A prepared statement object
4027 ** is the compiled object code. All SQL must be converted into a
4028 ** prepared statement before it can be run.
4029 **
4030 ** The life-cycle of a prepared statement object usually goes like this:
4031 **
4032 ** <ol>
4033 ** <li> Create the prepared statement object using [sqlite3_prepare_v2()].
4034 ** <li> Bind values to [parameters] using the sqlite3_bind_*()
4035 ** interfaces.
4036 ** <li> Run the SQL by calling [sqlite3_step()] one or more times.
4037 ** <li> Reset the prepared statement using [sqlite3_reset()] then go back
4038 ** to step 2. Do this zero or more times.
4039 ** <li> Destroy the object using [sqlite3_finalize()].
4040 ** </ol>
4041 */
4042 typedef struct sqlite3_stmt sqlite3_stmt;
4043
4044 /*
4045 ** CAPI3REF: Run-time Limits
4046 ** METHOD: sqlite3
4047 **
4048 ** ^(This interface allows the size of various constructs to be limited
4049 ** on a connection by connection basis. The first parameter is the
4050 ** [database connection] whose limit is to be set or queried. The
4051 ** second parameter is one of the [limit categories] that define a
4052 ** class of constructs to be size limited. The third parameter is the
4053 ** new limit for that construct.)^
4054 **
4055 ** ^If the new limit is a negative number, the limit is unchanged.
4056 ** ^(For each limit category SQLITE_LIMIT_<i>NAME</i> there is a
4057 ** [limits | hard upper bound]
4058 ** set at compile-time by a C preprocessor macro called
4059 ** [limits | SQLITE_MAX_<i>NAME</i>].
4060 ** (The "_LIMIT_" in the name is changed to "_MAX_".))^
4061 ** ^Attempts to increase a limit above its hard upper bound are
4062 ** silently truncated to the hard upper bound.
4063 **
4064 ** ^Regardless of whether or not the limit was changed, the
4065 ** [sqlite3_limit()] interface returns the prior value of the limit.
4066 ** ^Hence, to find the current value of a limit without changing it,
4067 ** simply invoke this interface with the third parameter set to -1.
4068 **
4069 ** Run-time limits are intended for use in applications that manage
4070 ** both their own internal database and also databases that are controlled
4071 ** by untrusted external sources. An example application might be a
4072 ** web browser that has its own databases for storing history and
4073 ** separate databases controlled by JavaScript applications downloaded
4074 ** off the Internet. The internal databases can be given the
4075 ** large, default limits. Databases managed by external sources can
4076 ** be given much smaller limits designed to prevent a denial of service
4077 ** attack. Developers might also want to use the [sqlite3_set_authorizer()]
4078 ** interface to further control untrusted SQL. The size of the database
4079 ** created by an untrusted script can be contained using the
4080 ** [max_page_count] [PRAGMA].
4081 **
4082 ** New run-time limit categories may be added in future releases.
4083 */
4084 SQLITE_API int sqlite3_limit(sqlite3*, int id, int newVal);
4085
4086 /*
4087 ** CAPI3REF: Run-Time Limit Categories
4088 ** KEYWORDS: {limit category} {*limit categories}
4089 **
4090 ** These constants define various performance limits
4091 ** that can be lowered at run-time using [sqlite3_limit()].
4092 ** The synopsis of the meanings of the various limits is shown below.
4093 ** Additional information is available at [limits | Limits in SQLite].
4094 **
4095 ** <dl>
4096 ** [[SQLITE_LIMIT_LENGTH]] ^(<dt>SQLITE_LIMIT_LENGTH</dt>
4097 ** <dd>The maximum size of any string or BLOB or table row, in bytes.<dd>)^
4098 **
4099 ** [[SQLITE_LIMIT_SQL_LENGTH]] ^(<dt>SQLITE_LIMIT_SQL_LENGTH</dt>
4100 ** <dd>The maximum length of an SQL statement, in bytes.</dd>)^
4101 **
4102 ** [[SQLITE_LIMIT_COLUMN]] ^(<dt>SQLITE_LIMIT_COLUMN</dt>
4103 ** <dd>The maximum number of columns in a table definition or in the
4104 ** result set of a [SELECT] or the maximum number of columns in an index
4105 ** or in an ORDER BY or GROUP BY clause.</dd>)^
4106 **
4107 ** [[SQLITE_LIMIT_EXPR_DEPTH]] ^(<dt>SQLITE_LIMIT_EXPR_DEPTH</dt>
4108 ** <dd>The maximum depth of the parse tree on any expression.</dd>)^
4109 **
4110 ** [[SQLITE_LIMIT_COMPOUND_SELECT]] ^(<dt>SQLITE_LIMIT_COMPOUND_SELECT</dt>
4111 ** <dd>The maximum number of terms in a compound SELECT statement.</dd>)^
4112 **
4113 ** [[SQLITE_LIMIT_VDBE_OP]] ^(<dt>SQLITE_LIMIT_VDBE_OP</dt>
4114 ** <dd>The maximum number of instructions in a virtual machine program
4115 ** used to implement an SQL statement. If [sqlite3_prepare_v2()] or
4116 ** the equivalent tries to allocate space for more than this many opcodes
4117 ** in a single prepared statement, an SQLITE_NOMEM error is returned.</dd>)^
4118 **
4119 ** [[SQLITE_LIMIT_FUNCTION_ARG]] ^(<dt>SQLITE_LIMIT_FUNCTION_ARG</dt>
4120 ** <dd>The maximum number of arguments on a function.</dd>)^
4121 **
4122 ** [[SQLITE_LIMIT_ATTACHED]] ^(<dt>SQLITE_LIMIT_ATTACHED</dt>
4123 ** <dd>The maximum number of [ATTACH | attached databases].)^</dd>
4124 **
4125 ** [[SQLITE_LIMIT_LIKE_PATTERN_LENGTH]]
4126 ** ^(<dt>SQLITE_LIMIT_LIKE_PATTERN_LENGTH</dt>
4127 ** <dd>The maximum length of the pattern argument to the [LIKE] or
4128 ** [GLOB] operators.</dd>)^
4129 **
4130 ** [[SQLITE_LIMIT_VARIABLE_NUMBER]]
4131 ** ^(<dt>SQLITE_LIMIT_VARIABLE_NUMBER</dt>
4132 ** <dd>The maximum index number of any [parameter] in an SQL statement.)^
4133 **
4134 ** [[SQLITE_LIMIT_TRIGGER_DEPTH]] ^(<dt>SQLITE_LIMIT_TRIGGER_DEPTH</dt>
4135 ** <dd>The maximum depth of recursion for triggers.</dd>)^
4136 **
4137 ** [[SQLITE_LIMIT_WORKER_THREADS]] ^(<dt>SQLITE_LIMIT_WORKER_THREADS</dt>
4138 ** <dd>The maximum number of auxiliary worker threads that a single
4139 ** [prepared statement] may start.</dd>)^
4140 ** </dl>
4141 */
4142 #define SQLITE_LIMIT_LENGTH 0
4143 #define SQLITE_LIMIT_SQL_LENGTH 1
4144 #define SQLITE_LIMIT_COLUMN 2
4145 #define SQLITE_LIMIT_EXPR_DEPTH 3
4146 #define SQLITE_LIMIT_COMPOUND_SELECT 4
4147 #define SQLITE_LIMIT_VDBE_OP 5
4148 #define SQLITE_LIMIT_FUNCTION_ARG 6
4149 #define SQLITE_LIMIT_ATTACHED 7
4150 #define SQLITE_LIMIT_LIKE_PATTERN_LENGTH 8
4151 #define SQLITE_LIMIT_VARIABLE_NUMBER 9
4152 #define SQLITE_LIMIT_TRIGGER_DEPTH 10
4153 #define SQLITE_LIMIT_WORKER_THREADS 11
4154
4155 /*
4156 ** CAPI3REF: Prepare Flags
4157 **
4158 ** These constants define various flags that can be passed into
4159 ** "prepFlags" parameter of the [sqlite3_prepare_v3()] and
4160 ** [sqlite3_prepare16_v3()] interfaces.
4161 **
4162 ** New flags may be added in future releases of SQLite.
4163 **
4164 ** <dl>
4165 ** [[SQLITE_PREPARE_PERSISTENT]] ^(<dt>SQLITE_PREPARE_PERSISTENT</dt>
4166 ** <dd>The SQLITE_PREPARE_PERSISTENT flag is a hint to the query planner
4167 ** that the prepared statement will be retained for a long time and
4168 ** probably reused many times.)^ ^Without this flag, [sqlite3_prepare_v3()]
4169 ** and [sqlite3_prepare16_v3()] assume that the prepared statement will
4170 ** be used just once or at most a few times and then destroyed using
4171 ** [sqlite3_finalize()] relatively soon. The current implementation acts
4172 ** on this hint by avoiding the use of [lookaside memory] so as not to
4173 ** deplete the limited store of lookaside memory. Future versions of
4174 ** SQLite may act on this hint differently.
4175 **
4176 ** [[SQLITE_PREPARE_NORMALIZE]] <dt>SQLITE_PREPARE_NORMALIZE</dt>
4177 ** <dd>The SQLITE_PREPARE_NORMALIZE flag is a no-op. This flag used
4178 ** to be required for any prepared statement that wanted to use the
4179 ** [sqlite3_normalized_sql()] interface. However, the
4180 ** [sqlite3_normalized_sql()] interface is now available to all
4181 ** prepared statements, regardless of whether or not they use this
4182 ** flag.
4183 **
4184 ** [[SQLITE_PREPARE_NO_VTAB]] <dt>SQLITE_PREPARE_NO_VTAB</dt>
4185 ** <dd>The SQLITE_PREPARE_NO_VTAB flag causes the SQL compiler
4186 ** to return an error (error code SQLITE_ERROR) if the statement uses
4187 ** any virtual tables.
4188 ** </dl>
4189 */
4190 #define SQLITE_PREPARE_PERSISTENT 0x01
4191 #define SQLITE_PREPARE_NORMALIZE 0x02
4192 #define SQLITE_PREPARE_NO_VTAB 0x04
4193
4194 /*
4195 ** CAPI3REF: Compiling An SQL Statement
4196 ** KEYWORDS: {SQL statement compiler}
4197 ** METHOD: sqlite3
4198 ** CONSTRUCTOR: sqlite3_stmt
4199 **
4200 ** To execute an SQL statement, it must first be compiled into a byte-code
4201 ** program using one of these routines. Or, in other words, these routines
4202 ** are constructors for the [prepared statement] object.
4203 **
4204 ** The preferred routine to use is [sqlite3_prepare_v2()]. The
4205 ** [sqlite3_prepare()] interface is legacy and should be avoided.
4206 ** [sqlite3_prepare_v3()] has an extra "prepFlags" option that is used
4207 ** for special purposes.
4208 **
4209 ** The use of the UTF-8 interfaces is preferred, as SQLite currently
4210 ** does all parsing using UTF-8. The UTF-16 interfaces are provided
4211 ** as a convenience. The UTF-16 interfaces work by converting the
4212 ** input text into UTF-8, then invoking the corresponding UTF-8 interface.
4213 **
4214 ** The first argument, "db", is a [database connection] obtained from a
4215 ** prior successful call to [sqlite3_open()], [sqlite3_open_v2()] or
4216 ** [sqlite3_open16()]. The database connection must not have been closed.
4217 **
4218 ** The second argument, "zSql", is the statement to be compiled, encoded
4219 ** as either UTF-8 or UTF-16. The sqlite3_prepare(), sqlite3_prepare_v2(),
4220 ** and sqlite3_prepare_v3()
4221 ** interfaces use UTF-8, and sqlite3_prepare16(), sqlite3_prepare16_v2(),
4222 ** and sqlite3_prepare16_v3() use UTF-16.
4223 **
4224 ** ^If the nByte argument is negative, then zSql is read up to the
4225 ** first zero terminator. ^If nByte is positive, then it is the
4226 ** number of bytes read from zSql. ^If nByte is zero, then no prepared
4227 ** statement is generated.
4228 ** If the caller knows that the supplied string is nul-terminated, then
4229 ** there is a small performance advantage to passing an nByte parameter that
4230 ** is the number of bytes in the input string <i>including</i>
4231 ** the nul-terminator.
4232 **
4233 ** ^If pzTail is not NULL then *pzTail is made to point to the first byte
4234 ** past the end of the first SQL statement in zSql. These routines only
4235 ** compile the first statement in zSql, so *pzTail is left pointing to
4236 ** what remains uncompiled.
4237 **
4238 ** ^*ppStmt is left pointing to a compiled [prepared statement] that can be
4239 ** executed using [sqlite3_step()]. ^If there is an error, *ppStmt is set
4240 ** to NULL. ^If the input text contains no SQL (if the input is an empty
4241 ** string or a comment) then *ppStmt is set to NULL.
4242 ** The calling procedure is responsible for deleting the compiled
4243 ** SQL statement using [sqlite3_finalize()] after it has finished with it.
4244 ** ppStmt may not be NULL.
4245 **
4246 ** ^On success, the sqlite3_prepare() family of routines return [SQLITE_OK];
4247 ** otherwise an [error code] is returned.
4248 **
4249 ** The sqlite3_prepare_v2(), sqlite3_prepare_v3(), sqlite3_prepare16_v2(),
4250 ** and sqlite3_prepare16_v3() interfaces are recommended for all new programs.
4251 ** The older interfaces (sqlite3_prepare() and sqlite3_prepare16())
4252 ** are retained for backwards compatibility, but their use is discouraged.
4253 ** ^In the "vX" interfaces, the prepared statement
4254 ** that is returned (the [sqlite3_stmt] object) contains a copy of the
4255 ** original SQL text. This causes the [sqlite3_step()] interface to
4256 ** behave differently in three ways:
4257 **
4258 ** <ol>
4259 ** <li>
4260 ** ^If the database schema changes, instead of returning [SQLITE_SCHEMA] as it
4261 ** always used to do, [sqlite3_step()] will automatically recompile the SQL
4262 ** statement and try to run it again. As many as [SQLITE_MAX_SCHEMA_RETRY]
4263 ** retries will occur before sqlite3_step() gives up and returns an error.
4264 ** </li>
4265 **
4266 ** <li>
4267 ** ^When an error occurs, [sqlite3_step()] will return one of the detailed
4268 ** [error codes] or [extended error codes]. ^The legacy behavior was that
4269 ** [sqlite3_step()] would only return a generic [SQLITE_ERROR] result code
4270 ** and the application would have to make a second call to [sqlite3_reset()]
4271 ** in order to find the underlying cause of the problem. With the "v2" prepare
4272 ** interfaces, the underlying reason for the error is returned immediately.
4273 ** </li>
4274 **
4275 ** <li>
4276 ** ^If the specific value bound to a [parameter | host parameter] in the
4277 ** WHERE clause might influence the choice of query plan for a statement,
4278 ** then the statement will be automatically recompiled, as if there had been
4279 ** a schema change, on the first [sqlite3_step()] call following any change
4280 ** to the [sqlite3_bind_text | bindings] of that [parameter].
4281 ** ^The specific value of a WHERE-clause [parameter] might influence the
4282 ** choice of query plan if the parameter is the left-hand side of a [LIKE]
4283 ** or [GLOB] operator or if the parameter is compared to an indexed column
4284 ** and the [SQLITE_ENABLE_STAT4] compile-time option is enabled.
4285 ** </li>
4286 ** </ol>
4287 **
4288 ** <p>^sqlite3_prepare_v3() differs from sqlite3_prepare_v2() only in having
4289 ** the extra prepFlags parameter, which is a bit array consisting of zero or
4290 ** more of the [SQLITE_PREPARE_PERSISTENT|SQLITE_PREPARE_*] flags. ^The
4291 ** sqlite3_prepare_v2() interface works exactly the same as
4292 ** sqlite3_prepare_v3() with a zero prepFlags parameter.
4293 */
4294 SQLITE_API int sqlite3_prepare(
4295 sqlite3 *db, /* Database handle */
4296 const char *zSql, /* SQL statement, UTF-8 encoded */
4297 int nByte, /* Maximum length of zSql in bytes. */
4298 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4299 const char **pzTail /* OUT: Pointer to unused portion of zSql */
4300 );
4301 SQLITE_API int sqlite3_prepare_v2(
4302 sqlite3 *db, /* Database handle */
4303 const char *zSql, /* SQL statement, UTF-8 encoded */
4304 int nByte, /* Maximum length of zSql in bytes. */
4305 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4306 const char **pzTail /* OUT: Pointer to unused portion of zSql */
4307 );
4308 SQLITE_API int sqlite3_prepare_v3(
4309 sqlite3 *db, /* Database handle */
4310 const char *zSql, /* SQL statement, UTF-8 encoded */
4311 int nByte, /* Maximum length of zSql in bytes. */
4312 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */
4313 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4314 const char **pzTail /* OUT: Pointer to unused portion of zSql */
4315 );
4316 SQLITE_API int sqlite3_prepare16(
4317 sqlite3 *db, /* Database handle */
4318 const void *zSql, /* SQL statement, UTF-16 encoded */
4319 int nByte, /* Maximum length of zSql in bytes. */
4320 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4321 const void **pzTail /* OUT: Pointer to unused portion of zSql */
4322 );
4323 SQLITE_API int sqlite3_prepare16_v2(
4324 sqlite3 *db, /* Database handle */
4325 const void *zSql, /* SQL statement, UTF-16 encoded */
4326 int nByte, /* Maximum length of zSql in bytes. */
4327 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4328 const void **pzTail /* OUT: Pointer to unused portion of zSql */
4329 );
4330 SQLITE_API int sqlite3_prepare16_v3(
4331 sqlite3 *db, /* Database handle */
4332 const void *zSql, /* SQL statement, UTF-16 encoded */
4333 int nByte, /* Maximum length of zSql in bytes. */
4334 unsigned int prepFlags, /* Zero or more SQLITE_PREPARE_ flags */
4335 sqlite3_stmt **ppStmt, /* OUT: Statement handle */
4336 const void **pzTail /* OUT: Pointer to unused portion of zSql */
4337 );
4338
4339 /*
4340 ** CAPI3REF: Retrieving Statement SQL
4341 ** METHOD: sqlite3_stmt
4342 **
4343 ** ^The sqlite3_sql(P) interface returns a pointer to a copy of the UTF-8
4344 ** SQL text used to create [prepared statement] P if P was
4345 ** created by [sqlite3_prepare_v2()], [sqlite3_prepare_v3()],
4346 ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()].
4347 ** ^The sqlite3_expanded_sql(P) interface returns a pointer to a UTF-8
4348 ** string containing the SQL text of prepared statement P with
4349 ** [bound parameters] expanded.
4350 ** ^The sqlite3_normalized_sql(P) interface returns a pointer to a UTF-8
4351 ** string containing the normalized SQL text of prepared statement P. The
4352 ** semantics used to normalize a SQL statement are unspecified and subject
4353 ** to change. At a minimum, literal values will be replaced with suitable
4354 ** placeholders.
4355 **
4356 ** ^(For example, if a prepared statement is created using the SQL
4357 ** text "SELECT $abc,:xyz" and if parameter $abc is bound to integer 2345
4358 ** and parameter :xyz is unbound, then sqlite3_sql() will return
4359 ** the original string, "SELECT $abc,:xyz" but sqlite3_expanded_sql()
4360 ** will return "SELECT 2345,NULL".)^
4361 **
4362 ** ^The sqlite3_expanded_sql() interface returns NULL if insufficient memory
4363 ** is available to hold the result, or if the result would exceed the
4364 ** the maximum string length determined by the [SQLITE_LIMIT_LENGTH].
4365 **
4366 ** ^The [SQLITE_TRACE_SIZE_LIMIT] compile-time option limits the size of
4367 ** bound parameter expansions. ^The [SQLITE_OMIT_TRACE] compile-time
4368 ** option causes sqlite3_expanded_sql() to always return NULL.
4369 **
4370 ** ^The strings returned by sqlite3_sql(P) and sqlite3_normalized_sql(P)
4371 ** are managed by SQLite and are automatically freed when the prepared
4372 ** statement is finalized.
4373 ** ^The string returned by sqlite3_expanded_sql(P), on the other hand,
4374 ** is obtained from [sqlite3_malloc()] and must be freed by the application
4375 ** by passing it to [sqlite3_free()].
4376 **
4377 ** ^The sqlite3_normalized_sql() interface is only available if
4378 ** the [SQLITE_ENABLE_NORMALIZE] compile-time option is defined.
4379 */
4380 SQLITE_API const char *sqlite3_sql(sqlite3_stmt *pStmt);
4381 SQLITE_API char *sqlite3_expanded_sql(sqlite3_stmt *pStmt);
4382 #ifdef SQLITE_ENABLE_NORMALIZE
4383 SQLITE_API const char *sqlite3_normalized_sql(sqlite3_stmt *pStmt);
4384 #endif
4385
4386 /*
4387 ** CAPI3REF: Determine If An SQL Statement Writes The Database
4388 ** METHOD: sqlite3_stmt
4389 **
4390 ** ^The sqlite3_stmt_readonly(X) interface returns true (non-zero) if
4391 ** and only if the [prepared statement] X makes no direct changes to
4392 ** the content of the database file.
4393 **
4394 ** Note that [application-defined SQL functions] or
4395 ** [virtual tables] might change the database indirectly as a side effect.
4396 ** ^(For example, if an application defines a function "eval()" that
4397 ** calls [sqlite3_exec()], then the following SQL statement would
4398 ** change the database file through side-effects:
4399 **
4400 ** <blockquote><pre>
4401 ** SELECT eval('DELETE FROM t1') FROM t2;
4402 ** </pre></blockquote>
4403 **
4404 ** But because the [SELECT] statement does not change the database file
4405 ** directly, sqlite3_stmt_readonly() would still return true.)^
4406 **
4407 ** ^Transaction control statements such as [BEGIN], [COMMIT], [ROLLBACK],
4408 ** [SAVEPOINT], and [RELEASE] cause sqlite3_stmt_readonly() to return true,
4409 ** since the statements themselves do not actually modify the database but
4410 ** rather they control the timing of when other statements modify the
4411 ** database. ^The [ATTACH] and [DETACH] statements also cause
4412 ** sqlite3_stmt_readonly() to return true since, while those statements
4413 ** change the configuration of a database connection, they do not make
4414 ** changes to the content of the database files on disk.
4415 ** ^The sqlite3_stmt_readonly() interface returns true for [BEGIN] since
4416 ** [BEGIN] merely sets internal flags, but the [BEGIN|BEGIN IMMEDIATE] and
4417 ** [BEGIN|BEGIN EXCLUSIVE] commands do touch the database and so
4418 ** sqlite3_stmt_readonly() returns false for those commands.
4419 **
4420 ** ^This routine returns false if there is any possibility that the
4421 ** statement might change the database file. ^A false return does
4422 ** not guarantee that the statement will change the database file.
4423 ** ^For example, an UPDATE statement might have a WHERE clause that
4424 ** makes it a no-op, but the sqlite3_stmt_readonly() result would still
4425 ** be false. ^Similarly, a CREATE TABLE IF NOT EXISTS statement is a
4426 ** read-only no-op if the table already exists, but
4427 ** sqlite3_stmt_readonly() still returns false for such a statement.
4428 **
4429 ** ^If prepared statement X is an [EXPLAIN] or [EXPLAIN QUERY PLAN]
4430 ** statement, then sqlite3_stmt_readonly(X) returns the same value as
4431 ** if the EXPLAIN or EXPLAIN QUERY PLAN prefix were omitted.
4432 */
4433 SQLITE_API int sqlite3_stmt_readonly(sqlite3_stmt *pStmt);
4434
4435 /*
4436 ** CAPI3REF: Query The EXPLAIN Setting For A Prepared Statement
4437 ** METHOD: sqlite3_stmt
4438 **
4439 ** ^The sqlite3_stmt_isexplain(S) interface returns 1 if the
4440 ** prepared statement S is an EXPLAIN statement, or 2 if the
4441 ** statement S is an EXPLAIN QUERY PLAN.
4442 ** ^The sqlite3_stmt_isexplain(S) interface returns 0 if S is
4443 ** an ordinary statement or a NULL pointer.
4444 */
4445 SQLITE_API int sqlite3_stmt_isexplain(sqlite3_stmt *pStmt);
4446
4447 /*
4448 ** CAPI3REF: Change The EXPLAIN Setting For A Prepared Statement
4449 ** METHOD: sqlite3_stmt
4450 **
4451 ** The sqlite3_stmt_explain(S,E) interface changes the EXPLAIN
4452 ** setting for [prepared statement] S. If E is zero, then S becomes
4453 ** a normal prepared statement. If E is 1, then S behaves as if
4454 ** its SQL text began with "[EXPLAIN]". If E is 2, then S behaves as if
4455 ** its SQL text began with "[EXPLAIN QUERY PLAN]".
4456 **
4457 ** Calling sqlite3_stmt_explain(S,E) might cause S to be reprepared.
4458 ** SQLite tries to avoid a reprepare, but a reprepare might be necessary
4459 ** on the first transition into EXPLAIN or EXPLAIN QUERY PLAN mode.
4460 **
4461 ** Because of the potential need to reprepare, a call to
4462 ** sqlite3_stmt_explain(S,E) will fail with SQLITE_ERROR if S cannot be
4463 ** reprepared because it was created using [sqlite3_prepare()] instead of
4464 ** the newer [sqlite3_prepare_v2()] or [sqlite3_prepare_v3()] interfaces and
4465 ** hence has no saved SQL text with which to reprepare.
4466 **
4467 ** Changing the explain setting for a prepared statement does not change
4468 ** the original SQL text for the statement. Hence, if the SQL text originally
4469 ** began with EXPLAIN or EXPLAIN QUERY PLAN, but sqlite3_stmt_explain(S,0)
4470 ** is called to convert the statement into an ordinary statement, the EXPLAIN
4471 ** or EXPLAIN QUERY PLAN keywords will still appear in the sqlite3_sql(S)
4472 ** output, even though the statement now acts like a normal SQL statement.
4473 **
4474 ** This routine returns SQLITE_OK if the explain mode is successfully
4475 ** changed, or an error code if the explain mode could not be changed.
4476 ** The explain mode cannot be changed while a statement is active.
4477 ** Hence, it is good practice to call [sqlite3_reset(S)]
4478 ** immediately prior to calling sqlite3_stmt_explain(S,E).
4479 */
4480 SQLITE_API int sqlite3_stmt_explain(sqlite3_stmt *pStmt, int eMode);
4481
4482 /*
4483 ** CAPI3REF: Determine If A Prepared Statement Has Been Reset
4484 ** METHOD: sqlite3_stmt
4485 **
4486 ** ^The sqlite3_stmt_busy(S) interface returns true (non-zero) if the
4487 ** [prepared statement] S has been stepped at least once using
4488 ** [sqlite3_step(S)] but has neither run to completion (returned
4489 ** [SQLITE_DONE] from [sqlite3_step(S)]) nor
4490 ** been reset using [sqlite3_reset(S)]. ^The sqlite3_stmt_busy(S)
4491 ** interface returns false if S is a NULL pointer. If S is not a
4492 ** NULL pointer and is not a pointer to a valid [prepared statement]
4493 ** object, then the behavior is undefined and probably undesirable.
4494 **
4495 ** This interface can be used in combination [sqlite3_next_stmt()]
4496 ** to locate all prepared statements associated with a database
4497 ** connection that are in need of being reset. This can be used,
4498 ** for example, in diagnostic routines to search for prepared
4499 ** statements that are holding a transaction open.
4500 */
4501 SQLITE_API int sqlite3_stmt_busy(sqlite3_stmt*);
4502
4503 /*
4504 ** CAPI3REF: Dynamically Typed Value Object
4505 ** KEYWORDS: {protected sqlite3_value} {unprotected sqlite3_value}
4506 **
4507 ** SQLite uses the sqlite3_value object to represent all values
4508 ** that can be stored in a database table. SQLite uses dynamic typing
4509 ** for the values it stores. ^Values stored in sqlite3_value objects
4510 ** can be integers, floating point values, strings, BLOBs, or NULL.
4511 **
4512 ** An sqlite3_value object may be either "protected" or "unprotected".
4513 ** Some interfaces require a protected sqlite3_value. Other interfaces
4514 ** will accept either a protected or an unprotected sqlite3_value.
4515 ** Every interface that accepts sqlite3_value arguments specifies
4516 ** whether or not it requires a protected sqlite3_value. The
4517 ** [sqlite3_value_dup()] interface can be used to construct a new
4518 ** protected sqlite3_value from an unprotected sqlite3_value.
4519 **
4520 ** The terms "protected" and "unprotected" refer to whether or not
4521 ** a mutex is held. An internal mutex is held for a protected
4522 ** sqlite3_value object but no mutex is held for an unprotected
4523 ** sqlite3_value object. If SQLite is compiled to be single-threaded
4524 ** (with [SQLITE_THREADSAFE=0] and with [sqlite3_threadsafe()] returning 0)
4525 ** or if SQLite is run in one of reduced mutex modes
4526 ** [SQLITE_CONFIG_SINGLETHREAD] or [SQLITE_CONFIG_MULTITHREAD]
4527 ** then there is no distinction between protected and unprotected
4528 ** sqlite3_value objects and they can be used interchangeably. However,
4529 ** for maximum code portability it is recommended that applications
4530 ** still make the distinction between protected and unprotected
4531 ** sqlite3_value objects even when not strictly required.
4532 **
4533 ** ^The sqlite3_value objects that are passed as parameters into the
4534 ** implementation of [application-defined SQL functions] are protected.
4535 ** ^The sqlite3_value objects returned by [sqlite3_vtab_rhs_value()]
4536 ** are protected.
4537 ** ^The sqlite3_value object returned by
4538 ** [sqlite3_column_value()] is unprotected.
4539 ** Unprotected sqlite3_value objects may only be used as arguments
4540 ** to [sqlite3_result_value()], [sqlite3_bind_value()], and
4541 ** [sqlite3_value_dup()].
4542 ** The [sqlite3_value_blob | sqlite3_value_type()] family of
4543 ** interfaces require protected sqlite3_value objects.
4544 */
4545 typedef struct sqlite3_value sqlite3_value;
4546
4547 /*
4548 ** CAPI3REF: SQL Function Context Object
4549 **
4550 ** The context in which an SQL function executes is stored in an
4551 ** sqlite3_context object. ^A pointer to an sqlite3_context object
4552 ** is always first parameter to [application-defined SQL functions].
4553 ** The application-defined SQL function implementation will pass this
4554 ** pointer through into calls to [sqlite3_result_int | sqlite3_result()],
4555 ** [sqlite3_aggregate_context()], [sqlite3_user_data()],
4556 ** [sqlite3_context_db_handle()], [sqlite3_get_auxdata()],
4557 ** and/or [sqlite3_set_auxdata()].
4558 */
4559 typedef struct sqlite3_context sqlite3_context;
4560
4561 /*
4562 ** CAPI3REF: Binding Values To Prepared Statements
4563 ** KEYWORDS: {host parameter} {host parameters} {host parameter name}
4564 ** KEYWORDS: {SQL parameter} {SQL parameters} {parameter binding}
4565 ** METHOD: sqlite3_stmt
4566 **
4567 ** ^(In the SQL statement text input to [sqlite3_prepare_v2()] and its variants,
4568 ** literals may be replaced by a [parameter] that matches one of following
4569 ** templates:
4570 **
4571 ** <ul>
4572 ** <li> ?
4573 ** <li> ?NNN
4574 ** <li> :VVV
4575 ** <li> @VVV
4576 ** <li> $VVV
4577 ** </ul>
4578 **
4579 ** In the templates above, NNN represents an integer literal,
4580 ** and VVV represents an alphanumeric identifier.)^ ^The values of these
4581 ** parameters (also called "host parameter names" or "SQL parameters")
4582 ** can be set using the sqlite3_bind_*() routines defined here.
4583 **
4584 ** ^The first argument to the sqlite3_bind_*() routines is always
4585 ** a pointer to the [sqlite3_stmt] object returned from
4586 ** [sqlite3_prepare_v2()] or its variants.
4587 **
4588 ** ^The second argument is the index of the SQL parameter to be set.
4589 ** ^The leftmost SQL parameter has an index of 1. ^When the same named
4590 ** SQL parameter is used more than once, second and subsequent
4591 ** occurrences have the same index as the first occurrence.
4592 ** ^The index for named parameters can be looked up using the
4593 ** [sqlite3_bind_parameter_index()] API if desired. ^The index
4594 ** for "?NNN" parameters is the value of NNN.
4595 ** ^The NNN value must be between 1 and the [sqlite3_limit()]
4596 ** parameter [SQLITE_LIMIT_VARIABLE_NUMBER] (default value: 32766).
4597 **
4598 ** ^The third argument is the value to bind to the parameter.
4599 ** ^If the third parameter to sqlite3_bind_text() or sqlite3_bind_text16()
4600 ** or sqlite3_bind_blob() is a NULL pointer then the fourth parameter
4601 ** is ignored and the end result is the same as sqlite3_bind_null().
4602 ** ^If the third parameter to sqlite3_bind_text() is not NULL, then
4603 ** it should be a pointer to well-formed UTF8 text.
4604 ** ^If the third parameter to sqlite3_bind_text16() is not NULL, then
4605 ** it should be a pointer to well-formed UTF16 text.
4606 ** ^If the third parameter to sqlite3_bind_text64() is not NULL, then
4607 ** it should be a pointer to a well-formed unicode string that is
4608 ** either UTF8 if the sixth parameter is SQLITE_UTF8, or UTF16
4609 ** otherwise.
4610 **
4611 ** [[byte-order determination rules]] ^The byte-order of
4612 ** UTF16 input text is determined by the byte-order mark (BOM, U+FEFF)
4613 ** found in first character, which is removed, or in the absence of a BOM
4614 ** the byte order is the native byte order of the host
4615 ** machine for sqlite3_bind_text16() or the byte order specified in
4616 ** the 6th parameter for sqlite3_bind_text64().)^
4617 ** ^If UTF16 input text contains invalid unicode
4618 ** characters, then SQLite might change those invalid characters
4619 ** into the unicode replacement character: U+FFFD.
4620 **
4621 ** ^(In those routines that have a fourth argument, its value is the
4622 ** number of bytes in the parameter. To be clear: the value is the
4623 ** number of <u>bytes</u> in the value, not the number of characters.)^
4624 ** ^If the fourth parameter to sqlite3_bind_text() or sqlite3_bind_text16()
4625 ** is negative, then the length of the string is
4626 ** the number of bytes up to the first zero terminator.
4627 ** If the fourth parameter to sqlite3_bind_blob() is negative, then
4628 ** the behavior is undefined.
4629 ** If a non-negative fourth parameter is provided to sqlite3_bind_text()
4630 ** or sqlite3_bind_text16() or sqlite3_bind_text64() then
4631 ** that parameter must be the byte offset
4632 ** where the NUL terminator would occur assuming the string were NUL
4633 ** terminated. If any NUL characters occurs at byte offsets less than
4634 ** the value of the fourth parameter then the resulting string value will
4635 ** contain embedded NULs. The result of expressions involving strings
4636 ** with embedded NULs is undefined.
4637 **
4638 ** ^The fifth argument to the BLOB and string binding interfaces controls
4639 ** or indicates the lifetime of the object referenced by the third parameter.
4640 ** These three options exist:
4641 ** ^ (1) A destructor to dispose of the BLOB or string after SQLite has finished
4642 ** with it may be passed. ^It is called to dispose of the BLOB or string even
4643 ** if the call to the bind API fails, except the destructor is not called if
4644 ** the third parameter is a NULL pointer or the fourth parameter is negative.
4645 ** ^ (2) The special constant, [SQLITE_STATIC], may be passed to indicate that
4646 ** the application remains responsible for disposing of the object. ^In this
4647 ** case, the object and the provided pointer to it must remain valid until
4648 ** either the prepared statement is finalized or the same SQL parameter is
4649 ** bound to something else, whichever occurs sooner.
4650 ** ^ (3) The constant, [SQLITE_TRANSIENT], may be passed to indicate that the
4651 ** object is to be copied prior to the return from sqlite3_bind_*(). ^The
4652 ** object and pointer to it must remain valid until then. ^SQLite will then
4653 ** manage the lifetime of its private copy.
4654 **
4655 ** ^The sixth argument to sqlite3_bind_text64() must be one of
4656 ** [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE]
4657 ** to specify the encoding of the text in the third parameter. If
4658 ** the sixth argument to sqlite3_bind_text64() is not one of the
4659 ** allowed values shown above, or if the text encoding is different
4660 ** from the encoding specified by the sixth parameter, then the behavior
4661 ** is undefined.
4662 **
4663 ** ^The sqlite3_bind_zeroblob() routine binds a BLOB of length N that
4664 ** is filled with zeroes. ^A zeroblob uses a fixed amount of memory
4665 ** (just an integer to hold its size) while it is being processed.
4666 ** Zeroblobs are intended to serve as placeholders for BLOBs whose
4667 ** content is later written using
4668 ** [sqlite3_blob_open | incremental BLOB I/O] routines.
4669 ** ^A negative value for the zeroblob results in a zero-length BLOB.
4670 **
4671 ** ^The sqlite3_bind_pointer(S,I,P,T,D) routine causes the I-th parameter in
4672 ** [prepared statement] S to have an SQL value of NULL, but to also be
4673 ** associated with the pointer P of type T. ^D is either a NULL pointer or
4674 ** a pointer to a destructor function for P. ^SQLite will invoke the
4675 ** destructor D with a single argument of P when it is finished using
4676 ** P. The T parameter should be a static string, preferably a string
4677 ** literal. The sqlite3_bind_pointer() routine is part of the
4678 ** [pointer passing interface] added for SQLite 3.20.0.
4679 **
4680 ** ^If any of the sqlite3_bind_*() routines are called with a NULL pointer
4681 ** for the [prepared statement] or with a prepared statement for which
4682 ** [sqlite3_step()] has been called more recently than [sqlite3_reset()],
4683 ** then the call will return [SQLITE_MISUSE]. If any sqlite3_bind_()
4684 ** routine is passed a [prepared statement] that has been finalized, the
4685 ** result is undefined and probably harmful.
4686 **
4687 ** ^Bindings are not cleared by the [sqlite3_reset()] routine.
4688 ** ^Unbound parameters are interpreted as NULL.
4689 **
4690 ** ^The sqlite3_bind_* routines return [SQLITE_OK] on success or an
4691 ** [error code] if anything goes wrong.
4692 ** ^[SQLITE_TOOBIG] might be returned if the size of a string or BLOB
4693 ** exceeds limits imposed by [sqlite3_limit]([SQLITE_LIMIT_LENGTH]) or
4694 ** [SQLITE_MAX_LENGTH].
4695 ** ^[SQLITE_RANGE] is returned if the parameter
4696 ** index is out of range. ^[SQLITE_NOMEM] is returned if malloc() fails.
4697 **
4698 ** See also: [sqlite3_bind_parameter_count()],
4699 ** [sqlite3_bind_parameter_name()], and [sqlite3_bind_parameter_index()].
4700 */
4701 SQLITE_API int sqlite3_bind_blob(sqlite3_stmt*, int, const void*, int n, void(*)(void*));
4702 SQLITE_API int sqlite3_bind_blob64(sqlite3_stmt*, int, const void*, sqlite3_uint64,
4703 void(*)(void*));
4704 SQLITE_API int sqlite3_bind_double(sqlite3_stmt*, int, double);
4705 SQLITE_API int sqlite3_bind_int(sqlite3_stmt*, int, int);
4706 SQLITE_API int sqlite3_bind_int64(sqlite3_stmt*, int, sqlite3_int64);
4707 SQLITE_API int sqlite3_bind_null(sqlite3_stmt*, int);
4708 SQLITE_API int sqlite3_bind_text(sqlite3_stmt*,int,const char*,int,void(*)(void*));
4709 SQLITE_API int sqlite3_bind_text16(sqlite3_stmt*, int, const void*, int, void(*)(void*));
4710 SQLITE_API int sqlite3_bind_text64(sqlite3_stmt*, int, const char*, sqlite3_uint64,
4711 void(*)(void*), unsigned char encoding);
4712 SQLITE_API int sqlite3_bind_value(sqlite3_stmt*, int, const sqlite3_value*);
4713 SQLITE_API int sqlite3_bind_pointer(sqlite3_stmt*, int, void*, const char*,void(*)(void*));
4714 SQLITE_API int sqlite3_bind_zeroblob(sqlite3_stmt*, int, int n);
4715 SQLITE_API int sqlite3_bind_zeroblob64(sqlite3_stmt*, int, sqlite3_uint64);
4716
4717 /*
4718 ** CAPI3REF: Number Of SQL Parameters
4719 ** METHOD: sqlite3_stmt
4720 **
4721 ** ^This routine can be used to find the number of [SQL parameters]
4722 ** in a [prepared statement]. SQL parameters are tokens of the
4723 ** form "?", "?NNN", ":AAA", "$AAA", or "@AAA" that serve as
4724 ** placeholders for values that are [sqlite3_bind_blob | bound]
4725 ** to the parameters at a later time.
4726 **
4727 ** ^(This routine actually returns the index of the largest (rightmost)
4728 ** parameter. For all forms except ?NNN, this will correspond to the
4729 ** number of unique parameters. If parameters of the ?NNN form are used,
4730 ** there may be gaps in the list.)^
4731 **
4732 ** See also: [sqlite3_bind_blob|sqlite3_bind()],
4733 ** [sqlite3_bind_parameter_name()], and
4734 ** [sqlite3_bind_parameter_index()].
4735 */
4736 SQLITE_API int sqlite3_bind_parameter_count(sqlite3_stmt*);
4737
4738 /*
4739 ** CAPI3REF: Name Of A Host Parameter
4740 ** METHOD: sqlite3_stmt
4741 **
4742 ** ^The sqlite3_bind_parameter_name(P,N) interface returns
4743 ** the name of the N-th [SQL parameter] in the [prepared statement] P.
4744 ** ^(SQL parameters of the form "?NNN" or ":AAA" or "@AAA" or "$AAA"
4745 ** have a name which is the string "?NNN" or ":AAA" or "@AAA" or "$AAA"
4746 ** respectively.
4747 ** In other words, the initial ":" or "$" or "@" or "?"
4748 ** is included as part of the name.)^
4749 ** ^Parameters of the form "?" without a following integer have no name
4750 ** and are referred to as "nameless" or "anonymous parameters".
4751 **
4752 ** ^The first host parameter has an index of 1, not 0.
4753 **
4754 ** ^If the value N is out of range or if the N-th parameter is
4755 ** nameless, then NULL is returned. ^The returned string is
4756 ** always in UTF-8 encoding even if the named parameter was
4757 ** originally specified as UTF-16 in [sqlite3_prepare16()],
4758 ** [sqlite3_prepare16_v2()], or [sqlite3_prepare16_v3()].
4759 **
4760 ** See also: [sqlite3_bind_blob|sqlite3_bind()],
4761 ** [sqlite3_bind_parameter_count()], and
4762 ** [sqlite3_bind_parameter_index()].
4763 */
4764 SQLITE_API const char *sqlite3_bind_parameter_name(sqlite3_stmt*, int);
4765
4766 /*
4767 ** CAPI3REF: Index Of A Parameter With A Given Name
4768 ** METHOD: sqlite3_stmt
4769 **
4770 ** ^Return the index of an SQL parameter given its name. ^The
4771 ** index value returned is suitable for use as the second
4772 ** parameter to [sqlite3_bind_blob|sqlite3_bind()]. ^A zero
4773 ** is returned if no matching parameter is found. ^The parameter
4774 ** name must be given in UTF-8 even if the original statement
4775 ** was prepared from UTF-16 text using [sqlite3_prepare16_v2()] or
4776 ** [sqlite3_prepare16_v3()].
4777 **
4778 ** See also: [sqlite3_bind_blob|sqlite3_bind()],
4779 ** [sqlite3_bind_parameter_count()], and
4780 ** [sqlite3_bind_parameter_name()].
4781 */
4782 SQLITE_API int sqlite3_bind_parameter_index(sqlite3_stmt*, const char *zName);
4783
4784 /*
4785 ** CAPI3REF: Reset All Bindings On A Prepared Statement
4786 ** METHOD: sqlite3_stmt
4787 **
4788 ** ^Contrary to the intuition of many, [sqlite3_reset()] does not reset
4789 ** the [sqlite3_bind_blob | bindings] on a [prepared statement].
4790 ** ^Use this routine to reset all host parameters to NULL.
4791 */
4792 SQLITE_API int sqlite3_clear_bindings(sqlite3_stmt*);
4793
4794 /*
4795 ** CAPI3REF: Number Of Columns In A Result Set
4796 ** METHOD: sqlite3_stmt
4797 **
4798 ** ^Return the number of columns in the result set returned by the
4799 ** [prepared statement]. ^If this routine returns 0, that means the
4800 ** [prepared statement] returns no data (for example an [UPDATE]).
4801 ** ^However, just because this routine returns a positive number does not
4802 ** mean that one or more rows of data will be returned. ^A SELECT statement
4803 ** will always have a positive sqlite3_column_count() but depending on the
4804 ** WHERE clause constraints and the table content, it might return no rows.
4805 **
4806 ** See also: [sqlite3_data_count()]
4807 */
4808 SQLITE_API int sqlite3_column_count(sqlite3_stmt *pStmt);
4809
4810 /*
4811 ** CAPI3REF: Column Names In A Result Set
4812 ** METHOD: sqlite3_stmt
4813 **
4814 ** ^These routines return the name assigned to a particular column
4815 ** in the result set of a [SELECT] statement. ^The sqlite3_column_name()
4816 ** interface returns a pointer to a zero-terminated UTF-8 string
4817 ** and sqlite3_column_name16() returns a pointer to a zero-terminated
4818 ** UTF-16 string. ^The first parameter is the [prepared statement]
4819 ** that implements the [SELECT] statement. ^The second parameter is the
4820 ** column number. ^The leftmost column is number 0.
4821 **
4822 ** ^The returned string pointer is valid until either the [prepared statement]
4823 ** is destroyed by [sqlite3_finalize()] or until the statement is automatically
4824 ** reprepared by the first call to [sqlite3_step()] for a particular run
4825 ** or until the next call to
4826 ** sqlite3_column_name() or sqlite3_column_name16() on the same column.
4827 **
4828 ** ^If sqlite3_malloc() fails during the processing of either routine
4829 ** (for example during a conversion from UTF-8 to UTF-16) then a
4830 ** NULL pointer is returned.
4831 **
4832 ** ^The name of a result column is the value of the "AS" clause for
4833 ** that column, if there is an AS clause. If there is no AS clause
4834 ** then the name of the column is unspecified and may change from
4835 ** one release of SQLite to the next.
4836 */
4837 SQLITE_API const char *sqlite3_column_name(sqlite3_stmt*, int N);
4838 SQLITE_API const void *sqlite3_column_name16(sqlite3_stmt*, int N);
4839
4840 /*
4841 ** CAPI3REF: Source Of Data In A Query Result
4842 ** METHOD: sqlite3_stmt
4843 **
4844 ** ^These routines provide a means to determine the database, table, and
4845 ** table column that is the origin of a particular result column in
4846 ** [SELECT] statement.
4847 ** ^The name of the database or table or column can be returned as
4848 ** either a UTF-8 or UTF-16 string. ^The _database_ routines return
4849 ** the database name, the _table_ routines return the table name, and
4850 ** the origin_ routines return the column name.
4851 ** ^The returned string is valid until the [prepared statement] is destroyed
4852 ** using [sqlite3_finalize()] or until the statement is automatically
4853 ** reprepared by the first call to [sqlite3_step()] for a particular run
4854 ** or until the same information is requested
4855 ** again in a different encoding.
4856 **
4857 ** ^The names returned are the original un-aliased names of the
4858 ** database, table, and column.
4859 **
4860 ** ^The first argument to these interfaces is a [prepared statement].
4861 ** ^These functions return information about the Nth result column returned by
4862 ** the statement, where N is the second function argument.
4863 ** ^The left-most column is column 0 for these routines.
4864 **
4865 ** ^If the Nth column returned by the statement is an expression or
4866 ** subquery and is not a column value, then all of these functions return
4867 ** NULL. ^These routines might also return NULL if a memory allocation error
4868 ** occurs. ^Otherwise, they return the name of the attached database, table,
4869 ** or column that query result column was extracted from.
4870 **
4871 ** ^As with all other SQLite APIs, those whose names end with "16" return
4872 ** UTF-16 encoded strings and the other functions return UTF-8.
4873 **
4874 ** ^These APIs are only available if the library was compiled with the
4875 ** [SQLITE_ENABLE_COLUMN_METADATA] C-preprocessor symbol.
4876 **
4877 ** If two or more threads call one or more
4878 ** [sqlite3_column_database_name | column metadata interfaces]
4879 ** for the same [prepared statement] and result column
4880 ** at the same time then the results are undefined.
4881 */
4882 SQLITE_API const char *sqlite3_column_database_name(sqlite3_stmt*,int);
4883 SQLITE_API const void *sqlite3_column_database_name16(sqlite3_stmt*,int);
4884 SQLITE_API const char *sqlite3_column_table_name(sqlite3_stmt*,int);
4885 SQLITE_API const void *sqlite3_column_table_name16(sqlite3_stmt*,int);
4886 SQLITE_API const char *sqlite3_column_origin_name(sqlite3_stmt*,int);
4887 SQLITE_API const void *sqlite3_column_origin_name16(sqlite3_stmt*,int);
4888
4889 /*
4890 ** CAPI3REF: Declared Datatype Of A Query Result
4891 ** METHOD: sqlite3_stmt
4892 **
4893 ** ^(The first parameter is a [prepared statement].
4894 ** If this statement is a [SELECT] statement and the Nth column of the
4895 ** returned result set of that [SELECT] is a table column (not an
4896 ** expression or subquery) then the declared type of the table
4897 ** column is returned.)^ ^If the Nth column of the result set is an
4898 ** expression or subquery, then a NULL pointer is returned.
4899 ** ^The returned string is always UTF-8 encoded.
4900 **
4901 ** ^(For example, given the database schema:
4902 **
4903 ** CREATE TABLE t1(c1 VARIANT);
4904 **
4905 ** and the following statement to be compiled:
4906 **
4907 ** SELECT c1 + 1, c1 FROM t1;
4908 **
4909 ** this routine would return the string "VARIANT" for the second result
4910 ** column (i==1), and a NULL pointer for the first result column (i==0).)^
4911 **
4912 ** ^SQLite uses dynamic run-time typing. ^So just because a column
4913 ** is declared to contain a particular type does not mean that the
4914 ** data stored in that column is of the declared type. SQLite is
4915 ** strongly typed, but the typing is dynamic not static. ^Type
4916 ** is associated with individual values, not with the containers
4917 ** used to hold those values.
4918 */
4919 SQLITE_API const char *sqlite3_column_decltype(sqlite3_stmt*,int);
4920 SQLITE_API const void *sqlite3_column_decltype16(sqlite3_stmt*,int);
4921
4922 /*
4923 ** CAPI3REF: Evaluate An SQL Statement
4924 ** METHOD: sqlite3_stmt
4925 **
4926 ** After a [prepared statement] has been prepared using any of
4927 ** [sqlite3_prepare_v2()], [sqlite3_prepare_v3()], [sqlite3_prepare16_v2()],
4928 ** or [sqlite3_prepare16_v3()] or one of the legacy
4929 ** interfaces [sqlite3_prepare()] or [sqlite3_prepare16()], this function
4930 ** must be called one or more times to evaluate the statement.
4931 **
4932 ** The details of the behavior of the sqlite3_step() interface depend
4933 ** on whether the statement was prepared using the newer "vX" interfaces
4934 ** [sqlite3_prepare_v3()], [sqlite3_prepare_v2()], [sqlite3_prepare16_v3()],
4935 ** [sqlite3_prepare16_v2()] or the older legacy
4936 ** interfaces [sqlite3_prepare()] and [sqlite3_prepare16()]. The use of the
4937 ** new "vX" interface is recommended for new applications but the legacy
4938 ** interface will continue to be supported.
4939 **
4940 ** ^In the legacy interface, the return value will be either [SQLITE_BUSY],
4941 ** [SQLITE_DONE], [SQLITE_ROW], [SQLITE_ERROR], or [SQLITE_MISUSE].
4942 ** ^With the "v2" interface, any of the other [result codes] or
4943 ** [extended result codes] might be returned as well.
4944 **
4945 ** ^[SQLITE_BUSY] means that the database engine was unable to acquire the
4946 ** database locks it needs to do its job. ^If the statement is a [COMMIT]
4947 ** or occurs outside of an explicit transaction, then you can retry the
4948 ** statement. If the statement is not a [COMMIT] and occurs within an
4949 ** explicit transaction then you should rollback the transaction before
4950 ** continuing.
4951 **
4952 ** ^[SQLITE_DONE] means that the statement has finished executing
4953 ** successfully. sqlite3_step() should not be called again on this virtual
4954 ** machine without first calling [sqlite3_reset()] to reset the virtual
4955 ** machine back to its initial state.
4956 **
4957 ** ^If the SQL statement being executed returns any data, then [SQLITE_ROW]
4958 ** is returned each time a new row of data is ready for processing by the
4959 ** caller. The values may be accessed using the [column access functions].
4960 ** sqlite3_step() is called again to retrieve the next row of data.
4961 **
4962 ** ^[SQLITE_ERROR] means that a run-time error (such as a constraint
4963 ** violation) has occurred. sqlite3_step() should not be called again on
4964 ** the VM. More information may be found by calling [sqlite3_errmsg()].
4965 ** ^With the legacy interface, a more specific error code (for example,
4966 ** [SQLITE_INTERRUPT], [SQLITE_SCHEMA], [SQLITE_CORRUPT], and so forth)
4967 ** can be obtained by calling [sqlite3_reset()] on the
4968 ** [prepared statement]. ^In the "v2" interface,
4969 ** the more specific error code is returned directly by sqlite3_step().
4970 **
4971 ** [SQLITE_MISUSE] means that the this routine was called inappropriately.
4972 ** Perhaps it was called on a [prepared statement] that has
4973 ** already been [sqlite3_finalize | finalized] or on one that had
4974 ** previously returned [SQLITE_ERROR] or [SQLITE_DONE]. Or it could
4975 ** be the case that the same database connection is being used by two or
4976 ** more threads at the same moment in time.
4977 **
4978 ** For all versions of SQLite up to and including 3.6.23.1, a call to
4979 ** [sqlite3_reset()] was required after sqlite3_step() returned anything
4980 ** other than [SQLITE_ROW] before any subsequent invocation of
4981 ** sqlite3_step(). Failure to reset the prepared statement using
4982 ** [sqlite3_reset()] would result in an [SQLITE_MISUSE] return from
4983 ** sqlite3_step(). But after [version 3.6.23.1] ([dateof:3.6.23.1],
4984 ** sqlite3_step() began
4985 ** calling [sqlite3_reset()] automatically in this circumstance rather
4986 ** than returning [SQLITE_MISUSE]. This is not considered a compatibility
4987 ** break because any application that ever receives an SQLITE_MISUSE error
4988 ** is broken by definition. The [SQLITE_OMIT_AUTORESET] compile-time option
4989 ** can be used to restore the legacy behavior.
4990 **
4991 ** <b>Goofy Interface Alert:</b> In the legacy interface, the sqlite3_step()
4992 ** API always returns a generic error code, [SQLITE_ERROR], following any
4993 ** error other than [SQLITE_BUSY] and [SQLITE_MISUSE]. You must call
4994 ** [sqlite3_reset()] or [sqlite3_finalize()] in order to find one of the
4995 ** specific [error codes] that better describes the error.
4996 ** We admit that this is a goofy design. The problem has been fixed
4997 ** with the "v2" interface. If you prepare all of your SQL statements
4998 ** using [sqlite3_prepare_v3()] or [sqlite3_prepare_v2()]
4999 ** or [sqlite3_prepare16_v2()] or [sqlite3_prepare16_v3()] instead
5000 ** of the legacy [sqlite3_prepare()] and [sqlite3_prepare16()] interfaces,
5001 ** then the more specific [error codes] are returned directly
5002 ** by sqlite3_step(). The use of the "vX" interfaces is recommended.
5003 */
5004 SQLITE_API int sqlite3_step(sqlite3_stmt*);
5005
5006 /*
5007 ** CAPI3REF: Number of columns in a result set
5008 ** METHOD: sqlite3_stmt
5009 **
5010 ** ^The sqlite3_data_count(P) interface returns the number of columns in the
5011 ** current row of the result set of [prepared statement] P.
5012 ** ^If prepared statement P does not have results ready to return
5013 ** (via calls to the [sqlite3_column_int | sqlite3_column()] family of
5014 ** interfaces) then sqlite3_data_count(P) returns 0.
5015 ** ^The sqlite3_data_count(P) routine also returns 0 if P is a NULL pointer.
5016 ** ^The sqlite3_data_count(P) routine returns 0 if the previous call to
5017 ** [sqlite3_step](P) returned [SQLITE_DONE]. ^The sqlite3_data_count(P)
5018 ** will return non-zero if previous call to [sqlite3_step](P) returned
5019 ** [SQLITE_ROW], except in the case of the [PRAGMA incremental_vacuum]
5020 ** where it always returns zero since each step of that multi-step
5021 ** pragma returns 0 columns of data.
5022 **
5023 ** See also: [sqlite3_column_count()]
5024 */
5025 SQLITE_API int sqlite3_data_count(sqlite3_stmt *pStmt);
5026
5027 /*
5028 ** CAPI3REF: Fundamental Datatypes
5029 ** KEYWORDS: SQLITE_TEXT
5030 **
5031 ** ^(Every value in SQLite has one of five fundamental datatypes:
5032 **
5033 ** <ul>
5034 ** <li> 64-bit signed integer
5035 ** <li> 64-bit IEEE floating point number
5036 ** <li> string
5037 ** <li> BLOB
5038 ** <li> NULL
5039 ** </ul>)^
5040 **
5041 ** These constants are codes for each of those types.
5042 **
5043 ** Note that the SQLITE_TEXT constant was also used in SQLite version 2
5044 ** for a completely different meaning. Software that links against both
5045 ** SQLite version 2 and SQLite version 3 should use SQLITE3_TEXT, not
5046 ** SQLITE_TEXT.
5047 */
5048 #define SQLITE_INTEGER 1
5049 #define SQLITE_FLOAT 2
5050 #define SQLITE_BLOB 4
5051 #define SQLITE_NULL 5
5052 #ifdef SQLITE_TEXT
5053 # undef SQLITE_TEXT
5054 #else
5055 # define SQLITE_TEXT 3
5056 #endif
5057 #define SQLITE3_TEXT 3
5058
5059 /*
5060 ** CAPI3REF: Result Values From A Query
5061 ** KEYWORDS: {column access functions}
5062 ** METHOD: sqlite3_stmt
5063 **
5064 ** <b>Summary:</b>
5065 ** <blockquote><table border=0 cellpadding=0 cellspacing=0>
5066 ** <tr><td><b>sqlite3_column_blob</b><td>&rarr;<td>BLOB result
5067 ** <tr><td><b>sqlite3_column_double</b><td>&rarr;<td>REAL result
5068 ** <tr><td><b>sqlite3_column_int</b><td>&rarr;<td>32-bit INTEGER result
5069 ** <tr><td><b>sqlite3_column_int64</b><td>&rarr;<td>64-bit INTEGER result
5070 ** <tr><td><b>sqlite3_column_text</b><td>&rarr;<td>UTF-8 TEXT result
5071 ** <tr><td><b>sqlite3_column_text16</b><td>&rarr;<td>UTF-16 TEXT result
5072 ** <tr><td><b>sqlite3_column_value</b><td>&rarr;<td>The result as an
5073 ** [sqlite3_value|unprotected sqlite3_value] object.
5074 ** <tr><td>&nbsp;<td>&nbsp;<td>&nbsp;
5075 ** <tr><td><b>sqlite3_column_bytes</b><td>&rarr;<td>Size of a BLOB
5076 ** or a UTF-8 TEXT result in bytes
5077 ** <tr><td><b>sqlite3_column_bytes16&nbsp;&nbsp;</b>
5078 ** <td>&rarr;&nbsp;&nbsp;<td>Size of UTF-16
5079 ** TEXT in bytes
5080 ** <tr><td><b>sqlite3_column_type</b><td>&rarr;<td>Default
5081 ** datatype of the result
5082 ** </table></blockquote>
5083 **
5084 ** <b>Details:</b>
5085 **
5086 ** ^These routines return information about a single column of the current
5087 ** result row of a query. ^In every case the first argument is a pointer
5088 ** to the [prepared statement] that is being evaluated (the [sqlite3_stmt*]
5089 ** that was returned from [sqlite3_prepare_v2()] or one of its variants)
5090 ** and the second argument is the index of the column for which information
5091 ** should be returned. ^The leftmost column of the result set has the index 0.
5092 ** ^The number of columns in the result can be determined using
5093 ** [sqlite3_column_count()].
5094 **
5095 ** If the SQL statement does not currently point to a valid row, or if the
5096 ** column index is out of range, the result is undefined.
5097 ** These routines may only be called when the most recent call to
5098 ** [sqlite3_step()] has returned [SQLITE_ROW] and neither
5099 ** [sqlite3_reset()] nor [sqlite3_finalize()] have been called subsequently.
5100 ** If any of these routines are called after [sqlite3_reset()] or
5101 ** [sqlite3_finalize()] or after [sqlite3_step()] has returned
5102 ** something other than [SQLITE_ROW], the results are undefined.
5103 ** If [sqlite3_step()] or [sqlite3_reset()] or [sqlite3_finalize()]
5104 ** are called from a different thread while any of these routines
5105 ** are pending, then the results are undefined.
5106 **
5107 ** The first six interfaces (_blob, _double, _int, _int64, _text, and _text16)
5108 ** each return the value of a result column in a specific data format. If
5109 ** the result column is not initially in the requested format (for example,
5110 ** if the query returns an integer but the sqlite3_column_text() interface
5111 ** is used to extract the value) then an automatic type conversion is performed.
5112 **
5113 ** ^The sqlite3_column_type() routine returns the
5114 ** [SQLITE_INTEGER | datatype code] for the initial data type
5115 ** of the result column. ^The returned value is one of [SQLITE_INTEGER],
5116 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].
5117 ** The return value of sqlite3_column_type() can be used to decide which
5118 ** of the first six interface should be used to extract the column value.
5119 ** The value returned by sqlite3_column_type() is only meaningful if no
5120 ** automatic type conversions have occurred for the value in question.
5121 ** After a type conversion, the result of calling sqlite3_column_type()
5122 ** is undefined, though harmless. Future
5123 ** versions of SQLite may change the behavior of sqlite3_column_type()
5124 ** following a type conversion.
5125 **
5126 ** If the result is a BLOB or a TEXT string, then the sqlite3_column_bytes()
5127 ** or sqlite3_column_bytes16() interfaces can be used to determine the size
5128 ** of that BLOB or string.
5129 **
5130 ** ^If the result is a BLOB or UTF-8 string then the sqlite3_column_bytes()
5131 ** routine returns the number of bytes in that BLOB or string.
5132 ** ^If the result is a UTF-16 string, then sqlite3_column_bytes() converts
5133 ** the string to UTF-8 and then returns the number of bytes.
5134 ** ^If the result is a numeric value then sqlite3_column_bytes() uses
5135 ** [sqlite3_snprintf()] to convert that value to a UTF-8 string and returns
5136 ** the number of bytes in that string.
5137 ** ^If the result is NULL, then sqlite3_column_bytes() returns zero.
5138 **
5139 ** ^If the result is a BLOB or UTF-16 string then the sqlite3_column_bytes16()
5140 ** routine returns the number of bytes in that BLOB or string.
5141 ** ^If the result is a UTF-8 string, then sqlite3_column_bytes16() converts
5142 ** the string to UTF-16 and then returns the number of bytes.
5143 ** ^If the result is a numeric value then sqlite3_column_bytes16() uses
5144 ** [sqlite3_snprintf()] to convert that value to a UTF-16 string and returns
5145 ** the number of bytes in that string.
5146 ** ^If the result is NULL, then sqlite3_column_bytes16() returns zero.
5147 **
5148 ** ^The values returned by [sqlite3_column_bytes()] and
5149 ** [sqlite3_column_bytes16()] do not include the zero terminators at the end
5150 ** of the string. ^For clarity: the values returned by
5151 ** [sqlite3_column_bytes()] and [sqlite3_column_bytes16()] are the number of
5152 ** bytes in the string, not the number of characters.
5153 **
5154 ** ^Strings returned by sqlite3_column_text() and sqlite3_column_text16(),
5155 ** even empty strings, are always zero-terminated. ^The return
5156 ** value from sqlite3_column_blob() for a zero-length BLOB is a NULL pointer.
5157 **
5158 ** ^Strings returned by sqlite3_column_text16() always have the endianness
5159 ** which is native to the platform, regardless of the text encoding set
5160 ** for the database.
5161 **
5162 ** <b>Warning:</b> ^The object returned by [sqlite3_column_value()] is an
5163 ** [unprotected sqlite3_value] object. In a multithreaded environment,
5164 ** an unprotected sqlite3_value object may only be used safely with
5165 ** [sqlite3_bind_value()] and [sqlite3_result_value()].
5166 ** If the [unprotected sqlite3_value] object returned by
5167 ** [sqlite3_column_value()] is used in any other way, including calls
5168 ** to routines like [sqlite3_value_int()], [sqlite3_value_text()],
5169 ** or [sqlite3_value_bytes()], the behavior is not threadsafe.
5170 ** Hence, the sqlite3_column_value() interface
5171 ** is normally only useful within the implementation of
5172 ** [application-defined SQL functions] or [virtual tables], not within
5173 ** top-level application code.
5174 **
5175 ** These routines may attempt to convert the datatype of the result.
5176 ** ^For example, if the internal representation is FLOAT and a text result
5177 ** is requested, [sqlite3_snprintf()] is used internally to perform the
5178 ** conversion automatically. ^(The following table details the conversions
5179 ** that are applied:
5180 **
5181 ** <blockquote>
5182 ** <table border="1">
5183 ** <tr><th> Internal<br>Type <th> Requested<br>Type <th> Conversion
5184 **
5185 ** <tr><td> NULL <td> INTEGER <td> Result is 0
5186 ** <tr><td> NULL <td> FLOAT <td> Result is 0.0
5187 ** <tr><td> NULL <td> TEXT <td> Result is a NULL pointer
5188 ** <tr><td> NULL <td> BLOB <td> Result is a NULL pointer
5189 ** <tr><td> INTEGER <td> FLOAT <td> Convert from integer to float
5190 ** <tr><td> INTEGER <td> TEXT <td> ASCII rendering of the integer
5191 ** <tr><td> INTEGER <td> BLOB <td> Same as INTEGER->TEXT
5192 ** <tr><td> FLOAT <td> INTEGER <td> [CAST] to INTEGER
5193 ** <tr><td> FLOAT <td> TEXT <td> ASCII rendering of the float
5194 ** <tr><td> FLOAT <td> BLOB <td> [CAST] to BLOB
5195 ** <tr><td> TEXT <td> INTEGER <td> [CAST] to INTEGER
5196 ** <tr><td> TEXT <td> FLOAT <td> [CAST] to REAL
5197 ** <tr><td> TEXT <td> BLOB <td> No change
5198 ** <tr><td> BLOB <td> INTEGER <td> [CAST] to INTEGER
5199 ** <tr><td> BLOB <td> FLOAT <td> [CAST] to REAL
5200 ** <tr><td> BLOB <td> TEXT <td> [CAST] to TEXT, ensure zero terminator
5201 ** </table>
5202 ** </blockquote>)^
5203 **
5204 ** Note that when type conversions occur, pointers returned by prior
5205 ** calls to sqlite3_column_blob(), sqlite3_column_text(), and/or
5206 ** sqlite3_column_text16() may be invalidated.
5207 ** Type conversions and pointer invalidations might occur
5208 ** in the following cases:
5209 **
5210 ** <ul>
5211 ** <li> The initial content is a BLOB and sqlite3_column_text() or
5212 ** sqlite3_column_text16() is called. A zero-terminator might
5213 ** need to be added to the string.</li>
5214 ** <li> The initial content is UTF-8 text and sqlite3_column_bytes16() or
5215 ** sqlite3_column_text16() is called. The content must be converted
5216 ** to UTF-16.</li>
5217 ** <li> The initial content is UTF-16 text and sqlite3_column_bytes() or
5218 ** sqlite3_column_text() is called. The content must be converted
5219 ** to UTF-8.</li>
5220 ** </ul>
5221 **
5222 ** ^Conversions between UTF-16be and UTF-16le are always done in place and do
5223 ** not invalidate a prior pointer, though of course the content of the buffer
5224 ** that the prior pointer references will have been modified. Other kinds
5225 ** of conversion are done in place when it is possible, but sometimes they
5226 ** are not possible and in those cases prior pointers are invalidated.
5227 **
5228 ** The safest policy is to invoke these routines
5229 ** in one of the following ways:
5230 **
5231 ** <ul>
5232 ** <li>sqlite3_column_text() followed by sqlite3_column_bytes()</li>
5233 ** <li>sqlite3_column_blob() followed by sqlite3_column_bytes()</li>
5234 ** <li>sqlite3_column_text16() followed by sqlite3_column_bytes16()</li>
5235 ** </ul>
5236 **
5237 ** In other words, you should call sqlite3_column_text(),
5238 ** sqlite3_column_blob(), or sqlite3_column_text16() first to force the result
5239 ** into the desired format, then invoke sqlite3_column_bytes() or
5240 ** sqlite3_column_bytes16() to find the size of the result. Do not mix calls
5241 ** to sqlite3_column_text() or sqlite3_column_blob() with calls to
5242 ** sqlite3_column_bytes16(), and do not mix calls to sqlite3_column_text16()
5243 ** with calls to sqlite3_column_bytes().
5244 **
5245 ** ^The pointers returned are valid until a type conversion occurs as
5246 ** described above, or until [sqlite3_step()] or [sqlite3_reset()] or
5247 ** [sqlite3_finalize()] is called. ^The memory space used to hold strings
5248 ** and BLOBs is freed automatically. Do not pass the pointers returned
5249 ** from [sqlite3_column_blob()], [sqlite3_column_text()], etc. into
5250 ** [sqlite3_free()].
5251 **
5252 ** As long as the input parameters are correct, these routines will only
5253 ** fail if an out-of-memory error occurs during a format conversion.
5254 ** Only the following subset of interfaces are subject to out-of-memory
5255 ** errors:
5256 **
5257 ** <ul>
5258 ** <li> sqlite3_column_blob()
5259 ** <li> sqlite3_column_text()
5260 ** <li> sqlite3_column_text16()
5261 ** <li> sqlite3_column_bytes()
5262 ** <li> sqlite3_column_bytes16()
5263 ** </ul>
5264 **
5265 ** If an out-of-memory error occurs, then the return value from these
5266 ** routines is the same as if the column had contained an SQL NULL value.
5267 ** Valid SQL NULL returns can be distinguished from out-of-memory errors
5268 ** by invoking the [sqlite3_errcode()] immediately after the suspect
5269 ** return value is obtained and before any
5270 ** other SQLite interface is called on the same [database connection].
5271 */
5272 SQLITE_API const void *sqlite3_column_blob(sqlite3_stmt*, int iCol);
5273 SQLITE_API double sqlite3_column_double(sqlite3_stmt*, int iCol);
5274 SQLITE_API int sqlite3_column_int(sqlite3_stmt*, int iCol);
5275 SQLITE_API sqlite3_int64 sqlite3_column_int64(sqlite3_stmt*, int iCol);
5276 SQLITE_API const unsigned char *sqlite3_column_text(sqlite3_stmt*, int iCol);
5277 SQLITE_API const void *sqlite3_column_text16(sqlite3_stmt*, int iCol);
5278 SQLITE_API sqlite3_value *sqlite3_column_value(sqlite3_stmt*, int iCol);
5279 SQLITE_API int sqlite3_column_bytes(sqlite3_stmt*, int iCol);
5280 SQLITE_API int sqlite3_column_bytes16(sqlite3_stmt*, int iCol);
5281 SQLITE_API int sqlite3_column_type(sqlite3_stmt*, int iCol);
5282
5283 /*
5284 ** CAPI3REF: Destroy A Prepared Statement Object
5285 ** DESTRUCTOR: sqlite3_stmt
5286 **
5287 ** ^The sqlite3_finalize() function is called to delete a [prepared statement].
5288 ** ^If the most recent evaluation of the statement encountered no errors
5289 ** or if the statement is never been evaluated, then sqlite3_finalize() returns
5290 ** SQLITE_OK. ^If the most recent evaluation of statement S failed, then
5291 ** sqlite3_finalize(S) returns the appropriate [error code] or
5292 ** [extended error code].
5293 **
5294 ** ^The sqlite3_finalize(S) routine can be called at any point during
5295 ** the life cycle of [prepared statement] S:
5296 ** before statement S is ever evaluated, after
5297 ** one or more calls to [sqlite3_reset()], or after any call
5298 ** to [sqlite3_step()] regardless of whether or not the statement has
5299 ** completed execution.
5300 **
5301 ** ^Invoking sqlite3_finalize() on a NULL pointer is a harmless no-op.
5302 **
5303 ** The application must finalize every [prepared statement] in order to avoid
5304 ** resource leaks. It is a grievous error for the application to try to use
5305 ** a prepared statement after it has been finalized. Any use of a prepared
5306 ** statement after it has been finalized can result in undefined and
5307 ** undesirable behavior such as segfaults and heap corruption.
5308 */
5309 SQLITE_API int sqlite3_finalize(sqlite3_stmt *pStmt);
5310
5311 /*
5312 ** CAPI3REF: Reset A Prepared Statement Object
5313 ** METHOD: sqlite3_stmt
5314 **
5315 ** The sqlite3_reset() function is called to reset a [prepared statement]
5316 ** object back to its initial state, ready to be re-executed.
5317 ** ^Any SQL statement variables that had values bound to them using
5318 ** the [sqlite3_bind_blob | sqlite3_bind_*() API] retain their values.
5319 ** Use [sqlite3_clear_bindings()] to reset the bindings.
5320 **
5321 ** ^The [sqlite3_reset(S)] interface resets the [prepared statement] S
5322 ** back to the beginning of its program.
5323 **
5324 ** ^The return code from [sqlite3_reset(S)] indicates whether or not
5325 ** the previous evaluation of prepared statement S completed successfully.
5326 ** ^If [sqlite3_step(S)] has never before been called on S or if
5327 ** [sqlite3_step(S)] has not been called since the previous call
5328 ** to [sqlite3_reset(S)], then [sqlite3_reset(S)] will return
5329 ** [SQLITE_OK].
5330 **
5331 ** ^If the most recent call to [sqlite3_step(S)] for the
5332 ** [prepared statement] S indicated an error, then
5333 ** [sqlite3_reset(S)] returns an appropriate [error code].
5334 ** ^The [sqlite3_reset(S)] interface might also return an [error code]
5335 ** if there were no prior errors but the process of resetting
5336 ** the prepared statement caused a new error. ^For example, if an
5337 ** [INSERT] statement with a [RETURNING] clause is only stepped one time,
5338 ** that one call to [sqlite3_step(S)] might return SQLITE_ROW but
5339 ** the overall statement might still fail and the [sqlite3_reset(S)] call
5340 ** might return SQLITE_BUSY if locking constraints prevent the
5341 ** database change from committing. Therefore, it is important that
5342 ** applications check the return code from [sqlite3_reset(S)] even if
5343 ** no prior call to [sqlite3_step(S)] indicated a problem.
5344 **
5345 ** ^The [sqlite3_reset(S)] interface does not change the values
5346 ** of any [sqlite3_bind_blob|bindings] on the [prepared statement] S.
5347 */
5348 SQLITE_API int sqlite3_reset(sqlite3_stmt *pStmt);
5349
5350
5351 /*
5352 ** CAPI3REF: Create Or Redefine SQL Functions
5353 ** KEYWORDS: {function creation routines}
5354 ** METHOD: sqlite3
5355 **
5356 ** ^These functions (collectively known as "function creation routines")
5357 ** are used to add SQL functions or aggregates or to redefine the behavior
5358 ** of existing SQL functions or aggregates. The only differences between
5359 ** the three "sqlite3_create_function*" routines are the text encoding
5360 ** expected for the second parameter (the name of the function being
5361 ** created) and the presence or absence of a destructor callback for
5362 ** the application data pointer. Function sqlite3_create_window_function()
5363 ** is similar, but allows the user to supply the extra callback functions
5364 ** needed by [aggregate window functions].
5365 **
5366 ** ^The first parameter is the [database connection] to which the SQL
5367 ** function is to be added. ^If an application uses more than one database
5368 ** connection then application-defined SQL functions must be added
5369 ** to each database connection separately.
5370 **
5371 ** ^The second parameter is the name of the SQL function to be created or
5372 ** redefined. ^The length of the name is limited to 255 bytes in a UTF-8
5373 ** representation, exclusive of the zero-terminator. ^Note that the name
5374 ** length limit is in UTF-8 bytes, not characters nor UTF-16 bytes.
5375 ** ^Any attempt to create a function with a longer name
5376 ** will result in [SQLITE_MISUSE] being returned.
5377 **
5378 ** ^The third parameter (nArg)
5379 ** is the number of arguments that the SQL function or
5380 ** aggregate takes. ^If this parameter is -1, then the SQL function or
5381 ** aggregate may take any number of arguments between 0 and the limit
5382 ** set by [sqlite3_limit]([SQLITE_LIMIT_FUNCTION_ARG]). If the third
5383 ** parameter is less than -1 or greater than 127 then the behavior is
5384 ** undefined.
5385 **
5386 ** ^The fourth parameter, eTextRep, specifies what
5387 ** [SQLITE_UTF8 | text encoding] this SQL function prefers for
5388 ** its parameters. The application should set this parameter to
5389 ** [SQLITE_UTF16LE] if the function implementation invokes
5390 ** [sqlite3_value_text16le()] on an input, or [SQLITE_UTF16BE] if the
5391 ** implementation invokes [sqlite3_value_text16be()] on an input, or
5392 ** [SQLITE_UTF16] if [sqlite3_value_text16()] is used, or [SQLITE_UTF8]
5393 ** otherwise. ^The same SQL function may be registered multiple times using
5394 ** different preferred text encodings, with different implementations for
5395 ** each encoding.
5396 ** ^When multiple implementations of the same function are available, SQLite
5397 ** will pick the one that involves the least amount of data conversion.
5398 **
5399 ** ^The fourth parameter may optionally be ORed with [SQLITE_DETERMINISTIC]
5400 ** to signal that the function will always return the same result given
5401 ** the same inputs within a single SQL statement. Most SQL functions are
5402 ** deterministic. The built-in [random()] SQL function is an example of a
5403 ** function that is not deterministic. The SQLite query planner is able to
5404 ** perform additional optimizations on deterministic functions, so use
5405 ** of the [SQLITE_DETERMINISTIC] flag is recommended where possible.
5406 **
5407 ** ^The fourth parameter may also optionally include the [SQLITE_DIRECTONLY]
5408 ** flag, which if present prevents the function from being invoked from
5409 ** within VIEWs, TRIGGERs, CHECK constraints, generated column expressions,
5410 ** index expressions, or the WHERE clause of partial indexes.
5411 **
5412 ** For best security, the [SQLITE_DIRECTONLY] flag is recommended for
5413 ** all application-defined SQL functions that do not need to be
5414 ** used inside of triggers, view, CHECK constraints, or other elements of
5415 ** the database schema. This flags is especially recommended for SQL
5416 ** functions that have side effects or reveal internal application state.
5417 ** Without this flag, an attacker might be able to modify the schema of
5418 ** a database file to include invocations of the function with parameters
5419 ** chosen by the attacker, which the application will then execute when
5420 ** the database file is opened and read.
5421 **
5422 ** ^(The fifth parameter is an arbitrary pointer. The implementation of the
5423 ** function can gain access to this pointer using [sqlite3_user_data()].)^
5424 **
5425 ** ^The sixth, seventh and eighth parameters passed to the three
5426 ** "sqlite3_create_function*" functions, xFunc, xStep and xFinal, are
5427 ** pointers to C-language functions that implement the SQL function or
5428 ** aggregate. ^A scalar SQL function requires an implementation of the xFunc
5429 ** callback only; NULL pointers must be passed as the xStep and xFinal
5430 ** parameters. ^An aggregate SQL function requires an implementation of xStep
5431 ** and xFinal and NULL pointer must be passed for xFunc. ^To delete an existing
5432 ** SQL function or aggregate, pass NULL pointers for all three function
5433 ** callbacks.
5434 **
5435 ** ^The sixth, seventh, eighth and ninth parameters (xStep, xFinal, xValue
5436 ** and xInverse) passed to sqlite3_create_window_function are pointers to
5437 ** C-language callbacks that implement the new function. xStep and xFinal
5438 ** must both be non-NULL. xValue and xInverse may either both be NULL, in
5439 ** which case a regular aggregate function is created, or must both be
5440 ** non-NULL, in which case the new function may be used as either an aggregate
5441 ** or aggregate window function. More details regarding the implementation
5442 ** of aggregate window functions are
5443 ** [user-defined window functions|available here].
5444 **
5445 ** ^(If the final parameter to sqlite3_create_function_v2() or
5446 ** sqlite3_create_window_function() is not NULL, then it is destructor for
5447 ** the application data pointer. The destructor is invoked when the function
5448 ** is deleted, either by being overloaded or when the database connection
5449 ** closes.)^ ^The destructor is also invoked if the call to
5450 ** sqlite3_create_function_v2() fails. ^When the destructor callback is
5451 ** invoked, it is passed a single argument which is a copy of the application
5452 ** data pointer which was the fifth parameter to sqlite3_create_function_v2().
5453 **
5454 ** ^It is permitted to register multiple implementations of the same
5455 ** functions with the same name but with either differing numbers of
5456 ** arguments or differing preferred text encodings. ^SQLite will use
5457 ** the implementation that most closely matches the way in which the
5458 ** SQL function is used. ^A function implementation with a non-negative
5459 ** nArg parameter is a better match than a function implementation with
5460 ** a negative nArg. ^A function where the preferred text encoding
5461 ** matches the database encoding is a better
5462 ** match than a function where the encoding is different.
5463 ** ^A function where the encoding difference is between UTF16le and UTF16be
5464 ** is a closer match than a function where the encoding difference is
5465 ** between UTF8 and UTF16.
5466 **
5467 ** ^Built-in functions may be overloaded by new application-defined functions.
5468 **
5469 ** ^An application-defined function is permitted to call other
5470 ** SQLite interfaces. However, such calls must not
5471 ** close the database connection nor finalize or reset the prepared
5472 ** statement in which the function is running.
5473 */
5474 SQLITE_API int sqlite3_create_function(
5475 sqlite3 *db,
5476 const char *zFunctionName,
5477 int nArg,
5478 int eTextRep,
5479 void *pApp,
5480 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
5481 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5482 void (*xFinal)(sqlite3_context*)
5483 );
5484 SQLITE_API int sqlite3_create_function16(
5485 sqlite3 *db,
5486 const void *zFunctionName,
5487 int nArg,
5488 int eTextRep,
5489 void *pApp,
5490 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
5491 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5492 void (*xFinal)(sqlite3_context*)
5493 );
5494 SQLITE_API int sqlite3_create_function_v2(
5495 sqlite3 *db,
5496 const char *zFunctionName,
5497 int nArg,
5498 int eTextRep,
5499 void *pApp,
5500 void (*xFunc)(sqlite3_context*,int,sqlite3_value**),
5501 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5502 void (*xFinal)(sqlite3_context*),
5503 void(*xDestroy)(void*)
5504 );
5505 SQLITE_API int sqlite3_create_window_function(
5506 sqlite3 *db,
5507 const char *zFunctionName,
5508 int nArg,
5509 int eTextRep,
5510 void *pApp,
5511 void (*xStep)(sqlite3_context*,int,sqlite3_value**),
5512 void (*xFinal)(sqlite3_context*),
5513 void (*xValue)(sqlite3_context*),
5514 void (*xInverse)(sqlite3_context*,int,sqlite3_value**),
5515 void(*xDestroy)(void*)
5516 );
5517
5518 /*
5519 ** CAPI3REF: Text Encodings
5520 **
5521 ** These constant define integer codes that represent the various
5522 ** text encodings supported by SQLite.
5523 */
5524 #define SQLITE_UTF8 1 /* IMP: R-37514-35566 */
5525 #define SQLITE_UTF16LE 2 /* IMP: R-03371-37637 */
5526 #define SQLITE_UTF16BE 3 /* IMP: R-51971-34154 */
5527 #define SQLITE_UTF16 4 /* Use native byte order */
5528 #define SQLITE_ANY 5 /* Deprecated */
5529 #define SQLITE_UTF16_ALIGNED 8 /* sqlite3_create_collation only */
5530
5531 /*
5532 ** CAPI3REF: Function Flags
5533 **
5534 ** These constants may be ORed together with the
5535 ** [SQLITE_UTF8 | preferred text encoding] as the fourth argument
5536 ** to [sqlite3_create_function()], [sqlite3_create_function16()], or
5537 ** [sqlite3_create_function_v2()].
5538 **
5539 ** <dl>
5540 ** [[SQLITE_DETERMINISTIC]] <dt>SQLITE_DETERMINISTIC</dt><dd>
5541 ** The SQLITE_DETERMINISTIC flag means that the new function always gives
5542 ** the same output when the input parameters are the same.
5543 ** The [abs|abs() function] is deterministic, for example, but
5544 ** [randomblob|randomblob()] is not. Functions must
5545 ** be deterministic in order to be used in certain contexts such as
5546 ** with the WHERE clause of [partial indexes] or in [generated columns].
5547 ** SQLite might also optimize deterministic functions by factoring them
5548 ** out of inner loops.
5549 ** </dd>
5550 **
5551 ** [[SQLITE_DIRECTONLY]] <dt>SQLITE_DIRECTONLY</dt><dd>
5552 ** The SQLITE_DIRECTONLY flag means that the function may only be invoked
5553 ** from top-level SQL, and cannot be used in VIEWs or TRIGGERs nor in
5554 ** schema structures such as [CHECK constraints], [DEFAULT clauses],
5555 ** [expression indexes], [partial indexes], or [generated columns].
5556 ** <p>
5557 ** The SQLITE_DIRECTONLY flag is recommended for any
5558 ** [application-defined SQL function]
5559 ** that has side-effects or that could potentially leak sensitive information.
5560 ** This will prevent attacks in which an application is tricked
5561 ** into using a database file that has had its schema surreptitiously
5562 ** modified to invoke the application-defined function in ways that are
5563 ** harmful.
5564 ** <p>
5565 ** Some people say it is good practice to set SQLITE_DIRECTONLY on all
5566 ** [application-defined SQL functions], regardless of whether or not they
5567 ** are security sensitive, as doing so prevents those functions from being used
5568 ** inside of the database schema, and thus ensures that the database
5569 ** can be inspected and modified using generic tools (such as the [CLI])
5570 ** that do not have access to the application-defined functions.
5571 ** </dd>
5572 **
5573 ** [[SQLITE_INNOCUOUS]] <dt>SQLITE_INNOCUOUS</dt><dd>
5574 ** The SQLITE_INNOCUOUS flag means that the function is unlikely
5575 ** to cause problems even if misused. An innocuous function should have
5576 ** no side effects and should not depend on any values other than its
5577 ** input parameters. The [abs|abs() function] is an example of an
5578 ** innocuous function.
5579 ** The [load_extension() SQL function] is not innocuous because of its
5580 ** side effects.
5581 ** <p> SQLITE_INNOCUOUS is similar to SQLITE_DETERMINISTIC, but is not
5582 ** exactly the same. The [random|random() function] is an example of a
5583 ** function that is innocuous but not deterministic.
5584 ** <p>Some heightened security settings
5585 ** ([SQLITE_DBCONFIG_TRUSTED_SCHEMA] and [PRAGMA trusted_schema=OFF])
5586 ** disable the use of SQL functions inside views and triggers and in
5587 ** schema structures such as [CHECK constraints], [DEFAULT clauses],
5588 ** [expression indexes], [partial indexes], and [generated columns] unless
5589 ** the function is tagged with SQLITE_INNOCUOUS. Most built-in functions
5590 ** are innocuous. Developers are advised to avoid using the
5591 ** SQLITE_INNOCUOUS flag for application-defined functions unless the
5592 ** function has been carefully audited and found to be free of potentially
5593 ** security-adverse side-effects and information-leaks.
5594 ** </dd>
5595 **
5596 ** [[SQLITE_SUBTYPE]] <dt>SQLITE_SUBTYPE</dt><dd>
5597 ** The SQLITE_SUBTYPE flag indicates to SQLite that a function might call
5598 ** [sqlite3_value_subtype()] to inspect the sub-types of its arguments.
5599 ** This flag instructs SQLite to omit some corner-case optimizations that
5600 ** might disrupt the operation of the [sqlite3_value_subtype()] function,
5601 ** causing it to return zero rather than the correct subtype().
5602 ** SQL functions that invokes [sqlite3_value_subtype()] should have this
5603 ** property. If the SQLITE_SUBTYPE property is omitted, then the return
5604 ** value from [sqlite3_value_subtype()] might sometimes be zero even though
5605 ** a non-zero subtype was specified by the function argument expression.
5606 **
5607 ** [[SQLITE_RESULT_SUBTYPE]] <dt>SQLITE_RESULT_SUBTYPE</dt><dd>
5608 ** The SQLITE_RESULT_SUBTYPE flag indicates to SQLite that a function might call
5609 ** [sqlite3_result_subtype()] to cause a sub-type to be associated with its
5610 ** result.
5611 ** Every function that invokes [sqlite3_result_subtype()] should have this
5612 ** property. If it does not, then the call to [sqlite3_result_subtype()]
5613 ** might become a no-op if the function is used as term in an
5614 ** [expression index]. On the other hand, SQL functions that never invoke
5615 ** [sqlite3_result_subtype()] should avoid setting this property, as the
5616 ** purpose of this property is to disable certain optimizations that are
5617 ** incompatible with subtypes.
5618 ** </dd>
5619 ** </dl>
5620 */
5621 #define SQLITE_DETERMINISTIC 0x000000800
5622 #define SQLITE_DIRECTONLY 0x000080000
5623 #define SQLITE_SUBTYPE 0x000100000
5624 #define SQLITE_INNOCUOUS 0x000200000
5625 #define SQLITE_RESULT_SUBTYPE 0x001000000
5626
5627 /*
5628 ** CAPI3REF: Deprecated Functions
5629 ** DEPRECATED
5630 **
5631 ** These functions are [deprecated]. In order to maintain
5632 ** backwards compatibility with older code, these functions continue
5633 ** to be supported. However, new applications should avoid
5634 ** the use of these functions. To encourage programmers to avoid
5635 ** these functions, we will not explain what they do.
5636 */
5637 #ifndef SQLITE_OMIT_DEPRECATED
5638 SQLITE_API SQLITE_DEPRECATED int sqlite3_aggregate_count(sqlite3_context*);
5639 SQLITE_API SQLITE_DEPRECATED int sqlite3_expired(sqlite3_stmt*);
5640 SQLITE_API SQLITE_DEPRECATED int sqlite3_transfer_bindings(sqlite3_stmt*, sqlite3_stmt*);
5641 SQLITE_API SQLITE_DEPRECATED int sqlite3_global_recover(void);
5642 SQLITE_API SQLITE_DEPRECATED void sqlite3_thread_cleanup(void);
5643 SQLITE_API SQLITE_DEPRECATED int sqlite3_memory_alarm(void(*)(void*,sqlite3_int64,int),
5644 void*,sqlite3_int64);
5645 #endif
5646
5647 /*
5648 ** CAPI3REF: Obtaining SQL Values
5649 ** METHOD: sqlite3_value
5650 **
5651 ** <b>Summary:</b>
5652 ** <blockquote><table border=0 cellpadding=0 cellspacing=0>
5653 ** <tr><td><b>sqlite3_value_blob</b><td>&rarr;<td>BLOB value
5654 ** <tr><td><b>sqlite3_value_double</b><td>&rarr;<td>REAL value
5655 ** <tr><td><b>sqlite3_value_int</b><td>&rarr;<td>32-bit INTEGER value
5656 ** <tr><td><b>sqlite3_value_int64</b><td>&rarr;<td>64-bit INTEGER value
5657 ** <tr><td><b>sqlite3_value_pointer</b><td>&rarr;<td>Pointer value
5658 ** <tr><td><b>sqlite3_value_text</b><td>&rarr;<td>UTF-8 TEXT value
5659 ** <tr><td><b>sqlite3_value_text16</b><td>&rarr;<td>UTF-16 TEXT value in
5660 ** the native byteorder
5661 ** <tr><td><b>sqlite3_value_text16be</b><td>&rarr;<td>UTF-16be TEXT value
5662 ** <tr><td><b>sqlite3_value_text16le</b><td>&rarr;<td>UTF-16le TEXT value
5663 ** <tr><td>&nbsp;<td>&nbsp;<td>&nbsp;
5664 ** <tr><td><b>sqlite3_value_bytes</b><td>&rarr;<td>Size of a BLOB
5665 ** or a UTF-8 TEXT in bytes
5666 ** <tr><td><b>sqlite3_value_bytes16&nbsp;&nbsp;</b>
5667 ** <td>&rarr;&nbsp;&nbsp;<td>Size of UTF-16
5668 ** TEXT in bytes
5669 ** <tr><td><b>sqlite3_value_type</b><td>&rarr;<td>Default
5670 ** datatype of the value
5671 ** <tr><td><b>sqlite3_value_numeric_type&nbsp;&nbsp;</b>
5672 ** <td>&rarr;&nbsp;&nbsp;<td>Best numeric datatype of the value
5673 ** <tr><td><b>sqlite3_value_nochange&nbsp;&nbsp;</b>
5674 ** <td>&rarr;&nbsp;&nbsp;<td>True if the column is unchanged in an UPDATE
5675 ** against a virtual table.
5676 ** <tr><td><b>sqlite3_value_frombind&nbsp;&nbsp;</b>
5677 ** <td>&rarr;&nbsp;&nbsp;<td>True if value originated from a [bound parameter]
5678 ** </table></blockquote>
5679 **
5680 ** <b>Details:</b>
5681 **
5682 ** These routines extract type, size, and content information from
5683 ** [protected sqlite3_value] objects. Protected sqlite3_value objects
5684 ** are used to pass parameter information into the functions that
5685 ** implement [application-defined SQL functions] and [virtual tables].
5686 **
5687 ** These routines work only with [protected sqlite3_value] objects.
5688 ** Any attempt to use these routines on an [unprotected sqlite3_value]
5689 ** is not threadsafe.
5690 **
5691 ** ^These routines work just like the corresponding [column access functions]
5692 ** except that these routines take a single [protected sqlite3_value] object
5693 ** pointer instead of a [sqlite3_stmt*] pointer and an integer column number.
5694 **
5695 ** ^The sqlite3_value_text16() interface extracts a UTF-16 string
5696 ** in the native byte-order of the host machine. ^The
5697 ** sqlite3_value_text16be() and sqlite3_value_text16le() interfaces
5698 ** extract UTF-16 strings as big-endian and little-endian respectively.
5699 **
5700 ** ^If [sqlite3_value] object V was initialized
5701 ** using [sqlite3_bind_pointer(S,I,P,X,D)] or [sqlite3_result_pointer(C,P,X,D)]
5702 ** and if X and Y are strings that compare equal according to strcmp(X,Y),
5703 ** then sqlite3_value_pointer(V,Y) will return the pointer P. ^Otherwise,
5704 ** sqlite3_value_pointer(V,Y) returns a NULL. The sqlite3_bind_pointer()
5705 ** routine is part of the [pointer passing interface] added for SQLite 3.20.0.
5706 **
5707 ** ^(The sqlite3_value_type(V) interface returns the
5708 ** [SQLITE_INTEGER | datatype code] for the initial datatype of the
5709 ** [sqlite3_value] object V. The returned value is one of [SQLITE_INTEGER],
5710 ** [SQLITE_FLOAT], [SQLITE_TEXT], [SQLITE_BLOB], or [SQLITE_NULL].)^
5711 ** Other interfaces might change the datatype for an sqlite3_value object.
5712 ** For example, if the datatype is initially SQLITE_INTEGER and
5713 ** sqlite3_value_text(V) is called to extract a text value for that
5714 ** integer, then subsequent calls to sqlite3_value_type(V) might return
5715 ** SQLITE_TEXT. Whether or not a persistent internal datatype conversion
5716 ** occurs is undefined and may change from one release of SQLite to the next.
5717 **
5718 ** ^(The sqlite3_value_numeric_type() interface attempts to apply
5719 ** numeric affinity to the value. This means that an attempt is
5720 ** made to convert the value to an integer or floating point. If
5721 ** such a conversion is possible without loss of information (in other
5722 ** words, if the value is a string that looks like a number)
5723 ** then the conversion is performed. Otherwise no conversion occurs.
5724 ** The [SQLITE_INTEGER | datatype] after conversion is returned.)^
5725 **
5726 ** ^Within the [xUpdate] method of a [virtual table], the
5727 ** sqlite3_value_nochange(X) interface returns true if and only if
5728 ** the column corresponding to X is unchanged by the UPDATE operation
5729 ** that the xUpdate method call was invoked to implement and if
5730 ** and the prior [xColumn] method call that was invoked to extracted
5731 ** the value for that column returned without setting a result (probably
5732 ** because it queried [sqlite3_vtab_nochange()] and found that the column
5733 ** was unchanging). ^Within an [xUpdate] method, any value for which
5734 ** sqlite3_value_nochange(X) is true will in all other respects appear
5735 ** to be a NULL value. If sqlite3_value_nochange(X) is invoked anywhere other
5736 ** than within an [xUpdate] method call for an UPDATE statement, then
5737 ** the return value is arbitrary and meaningless.
5738 **
5739 ** ^The sqlite3_value_frombind(X) interface returns non-zero if the
5740 ** value X originated from one of the [sqlite3_bind_int|sqlite3_bind()]
5741 ** interfaces. ^If X comes from an SQL literal value, or a table column,
5742 ** or an expression, then sqlite3_value_frombind(X) returns zero.
5743 **
5744 ** Please pay particular attention to the fact that the pointer returned
5745 ** from [sqlite3_value_blob()], [sqlite3_value_text()], or
5746 ** [sqlite3_value_text16()] can be invalidated by a subsequent call to
5747 ** [sqlite3_value_bytes()], [sqlite3_value_bytes16()], [sqlite3_value_text()],
5748 ** or [sqlite3_value_text16()].
5749 **
5750 ** These routines must be called from the same thread as
5751 ** the SQL function that supplied the [sqlite3_value*] parameters.
5752 **
5753 ** As long as the input parameter is correct, these routines can only
5754 ** fail if an out-of-memory error occurs during a format conversion.
5755 ** Only the following subset of interfaces are subject to out-of-memory
5756 ** errors:
5757 **
5758 ** <ul>
5759 ** <li> sqlite3_value_blob()
5760 ** <li> sqlite3_value_text()
5761 ** <li> sqlite3_value_text16()
5762 ** <li> sqlite3_value_text16le()
5763 ** <li> sqlite3_value_text16be()
5764 ** <li> sqlite3_value_bytes()
5765 ** <li> sqlite3_value_bytes16()
5766 ** </ul>
5767 **
5768 ** If an out-of-memory error occurs, then the return value from these
5769 ** routines is the same as if the column had contained an SQL NULL value.
5770 ** Valid SQL NULL returns can be distinguished from out-of-memory errors
5771 ** by invoking the [sqlite3_errcode()] immediately after the suspect
5772 ** return value is obtained and before any
5773 ** other SQLite interface is called on the same [database connection].
5774 */
5775 SQLITE_API const void *sqlite3_value_blob(sqlite3_value*);
5776 SQLITE_API double sqlite3_value_double(sqlite3_value*);
5777 SQLITE_API int sqlite3_value_int(sqlite3_value*);
5778 SQLITE_API sqlite3_int64 sqlite3_value_int64(sqlite3_value*);
5779 SQLITE_API void *sqlite3_value_pointer(sqlite3_value*, const char*);
5780 SQLITE_API const unsigned char *sqlite3_value_text(sqlite3_value*);
5781 SQLITE_API const void *sqlite3_value_text16(sqlite3_value*);
5782 SQLITE_API const void *sqlite3_value_text16le(sqlite3_value*);
5783 SQLITE_API const void *sqlite3_value_text16be(sqlite3_value*);
5784 SQLITE_API int sqlite3_value_bytes(sqlite3_value*);
5785 SQLITE_API int sqlite3_value_bytes16(sqlite3_value*);
5786 SQLITE_API int sqlite3_value_type(sqlite3_value*);
5787 SQLITE_API int sqlite3_value_numeric_type(sqlite3_value*);
5788 SQLITE_API int sqlite3_value_nochange(sqlite3_value*);
5789 SQLITE_API int sqlite3_value_frombind(sqlite3_value*);
5790
5791 /*
5792 ** CAPI3REF: Report the internal text encoding state of an sqlite3_value object
5793 ** METHOD: sqlite3_value
5794 **
5795 ** ^(The sqlite3_value_encoding(X) interface returns one of [SQLITE_UTF8],
5796 ** [SQLITE_UTF16BE], or [SQLITE_UTF16LE] according to the current text encoding
5797 ** of the value X, assuming that X has type TEXT.)^ If sqlite3_value_type(X)
5798 ** returns something other than SQLITE_TEXT, then the return value from
5799 ** sqlite3_value_encoding(X) is meaningless. ^Calls to
5800 ** [sqlite3_value_text(X)], [sqlite3_value_text16(X)], [sqlite3_value_text16be(X)],
5801 ** [sqlite3_value_text16le(X)], [sqlite3_value_bytes(X)], or
5802 ** [sqlite3_value_bytes16(X)] might change the encoding of the value X and
5803 ** thus change the return from subsequent calls to sqlite3_value_encoding(X).
5804 **
5805 ** This routine is intended for used by applications that test and validate
5806 ** the SQLite implementation. This routine is inquiring about the opaque
5807 ** internal state of an [sqlite3_value] object. Ordinary applications should
5808 ** not need to know what the internal state of an sqlite3_value object is and
5809 ** hence should not need to use this interface.
5810 */
5811 SQLITE_API int sqlite3_value_encoding(sqlite3_value*);
5812
5813 /*
5814 ** CAPI3REF: Finding The Subtype Of SQL Values
5815 ** METHOD: sqlite3_value
5816 **
5817 ** The sqlite3_value_subtype(V) function returns the subtype for
5818 ** an [application-defined SQL function] argument V. The subtype
5819 ** information can be used to pass a limited amount of context from
5820 ** one SQL function to another. Use the [sqlite3_result_subtype()]
5821 ** routine to set the subtype for the return value of an SQL function.
5822 **
5823 ** Every [application-defined SQL function] that invoke this interface
5824 ** should include the [SQLITE_SUBTYPE] property in the text
5825 ** encoding argument when the function is [sqlite3_create_function|registered].
5826 ** If the [SQLITE_SUBTYPE] property is omitted, then sqlite3_value_subtype()
5827 ** might return zero instead of the upstream subtype in some corner cases.
5828 */
5829 SQLITE_API unsigned int sqlite3_value_subtype(sqlite3_value*);
5830
5831 /*
5832 ** CAPI3REF: Copy And Free SQL Values
5833 ** METHOD: sqlite3_value
5834 **
5835 ** ^The sqlite3_value_dup(V) interface makes a copy of the [sqlite3_value]
5836 ** object D and returns a pointer to that copy. ^The [sqlite3_value] returned
5837 ** is a [protected sqlite3_value] object even if the input is not.
5838 ** ^The sqlite3_value_dup(V) interface returns NULL if V is NULL or if a
5839 ** memory allocation fails. ^If V is a [pointer value], then the result
5840 ** of sqlite3_value_dup(V) is a NULL value.
5841 **
5842 ** ^The sqlite3_value_free(V) interface frees an [sqlite3_value] object
5843 ** previously obtained from [sqlite3_value_dup()]. ^If V is a NULL pointer
5844 ** then sqlite3_value_free(V) is a harmless no-op.
5845 */
5846 SQLITE_API sqlite3_value *sqlite3_value_dup(const sqlite3_value*);
5847 SQLITE_API void sqlite3_value_free(sqlite3_value*);
5848
5849 /*
5850 ** CAPI3REF: Obtain Aggregate Function Context
5851 ** METHOD: sqlite3_context
5852 **
5853 ** Implementations of aggregate SQL functions use this
5854 ** routine to allocate memory for storing their state.
5855 **
5856 ** ^The first time the sqlite3_aggregate_context(C,N) routine is called
5857 ** for a particular aggregate function, SQLite allocates
5858 ** N bytes of memory, zeroes out that memory, and returns a pointer
5859 ** to the new memory. ^On second and subsequent calls to
5860 ** sqlite3_aggregate_context() for the same aggregate function instance,
5861 ** the same buffer is returned. Sqlite3_aggregate_context() is normally
5862 ** called once for each invocation of the xStep callback and then one
5863 ** last time when the xFinal callback is invoked. ^(When no rows match
5864 ** an aggregate query, the xStep() callback of the aggregate function
5865 ** implementation is never called and xFinal() is called exactly once.
5866 ** In those cases, sqlite3_aggregate_context() might be called for the
5867 ** first time from within xFinal().)^
5868 **
5869 ** ^The sqlite3_aggregate_context(C,N) routine returns a NULL pointer
5870 ** when first called if N is less than or equal to zero or if a memory
5871 ** allocation error occurs.
5872 **
5873 ** ^(The amount of space allocated by sqlite3_aggregate_context(C,N) is
5874 ** determined by the N parameter on first successful call. Changing the
5875 ** value of N in any subsequent call to sqlite3_aggregate_context() within
5876 ** the same aggregate function instance will not resize the memory
5877 ** allocation.)^ Within the xFinal callback, it is customary to set
5878 ** N=0 in calls to sqlite3_aggregate_context(C,N) so that no
5879 ** pointless memory allocations occur.
5880 **
5881 ** ^SQLite automatically frees the memory allocated by
5882 ** sqlite3_aggregate_context() when the aggregate query concludes.
5883 **
5884 ** The first parameter must be a copy of the
5885 ** [sqlite3_context | SQL function context] that is the first parameter
5886 ** to the xStep or xFinal callback routine that implements the aggregate
5887 ** function.
5888 **
5889 ** This routine must be called from the same thread in which
5890 ** the aggregate SQL function is running.
5891 */
5892 SQLITE_API void *sqlite3_aggregate_context(sqlite3_context*, int nBytes);
5893
5894 /*
5895 ** CAPI3REF: User Data For Functions
5896 ** METHOD: sqlite3_context
5897 **
5898 ** ^The sqlite3_user_data() interface returns a copy of
5899 ** the pointer that was the pUserData parameter (the 5th parameter)
5900 ** of the [sqlite3_create_function()]
5901 ** and [sqlite3_create_function16()] routines that originally
5902 ** registered the application defined function.
5903 **
5904 ** This routine must be called from the same thread in which
5905 ** the application-defined function is running.
5906 */
5907 SQLITE_API void *sqlite3_user_data(sqlite3_context*);
5908
5909 /*
5910 ** CAPI3REF: Database Connection For Functions
5911 ** METHOD: sqlite3_context
5912 **
5913 ** ^The sqlite3_context_db_handle() interface returns a copy of
5914 ** the pointer to the [database connection] (the 1st parameter)
5915 ** of the [sqlite3_create_function()]
5916 ** and [sqlite3_create_function16()] routines that originally
5917 ** registered the application defined function.
5918 */
5919 SQLITE_API sqlite3 *sqlite3_context_db_handle(sqlite3_context*);
5920
5921 /*
5922 ** CAPI3REF: Function Auxiliary Data
5923 ** METHOD: sqlite3_context
5924 **
5925 ** These functions may be used by (non-aggregate) SQL functions to
5926 ** associate auxiliary data with argument values. If the same argument
5927 ** value is passed to multiple invocations of the same SQL function during
5928 ** query execution, under some circumstances the associated auxiliary data
5929 ** might be preserved. An example of where this might be useful is in a
5930 ** regular-expression matching function. The compiled version of the regular
5931 ** expression can be stored as auxiliary data associated with the pattern string.
5932 ** Then as long as the pattern string remains the same,
5933 ** the compiled regular expression can be reused on multiple
5934 ** invocations of the same function.
5935 **
5936 ** ^The sqlite3_get_auxdata(C,N) interface returns a pointer to the auxiliary data
5937 ** associated by the sqlite3_set_auxdata(C,N,P,X) function with the Nth argument
5938 ** value to the application-defined function. ^N is zero for the left-most
5939 ** function argument. ^If there is no auxiliary data
5940 ** associated with the function argument, the sqlite3_get_auxdata(C,N) interface
5941 ** returns a NULL pointer.
5942 **
5943 ** ^The sqlite3_set_auxdata(C,N,P,X) interface saves P as auxiliary data for the
5944 ** N-th argument of the application-defined function. ^Subsequent
5945 ** calls to sqlite3_get_auxdata(C,N) return P from the most recent
5946 ** sqlite3_set_auxdata(C,N,P,X) call if the auxiliary data is still valid or
5947 ** NULL if the auxiliary data has been discarded.
5948 ** ^After each call to sqlite3_set_auxdata(C,N,P,X) where X is not NULL,
5949 ** SQLite will invoke the destructor function X with parameter P exactly
5950 ** once, when the auxiliary data is discarded.
5951 ** SQLite is free to discard the auxiliary data at any time, including: <ul>
5952 ** <li> ^(when the corresponding function parameter changes)^, or
5953 ** <li> ^(when [sqlite3_reset()] or [sqlite3_finalize()] is called for the
5954 ** SQL statement)^, or
5955 ** <li> ^(when sqlite3_set_auxdata() is invoked again on the same
5956 ** parameter)^, or
5957 ** <li> ^(during the original sqlite3_set_auxdata() call when a memory
5958 ** allocation error occurs.)^
5959 ** <li> ^(during the original sqlite3_set_auxdata() call if the function
5960 ** is evaluated during query planning instead of during query execution,
5961 ** as sometimes happens with [SQLITE_ENABLE_STAT4].)^ </ul>
5962 **
5963 ** Note the last two bullets in particular. The destructor X in
5964 ** sqlite3_set_auxdata(C,N,P,X) might be called immediately, before the
5965 ** sqlite3_set_auxdata() interface even returns. Hence sqlite3_set_auxdata()
5966 ** should be called near the end of the function implementation and the
5967 ** function implementation should not make any use of P after
5968 ** sqlite3_set_auxdata() has been called. Furthermore, a call to
5969 ** sqlite3_get_auxdata() that occurs immediately after a corresponding call
5970 ** to sqlite3_set_auxdata() might still return NULL if an out-of-memory
5971 ** condition occurred during the sqlite3_set_auxdata() call or if the
5972 ** function is being evaluated during query planning rather than during
5973 ** query execution.
5974 **
5975 ** ^(In practice, auxiliary data is preserved between function calls for
5976 ** function parameters that are compile-time constants, including literal
5977 ** values and [parameters] and expressions composed from the same.)^
5978 **
5979 ** The value of the N parameter to these interfaces should be non-negative.
5980 ** Future enhancements may make use of negative N values to define new
5981 ** kinds of function caching behavior.
5982 **
5983 ** These routines must be called from the same thread in which
5984 ** the SQL function is running.
5985 **
5986 ** See also: [sqlite3_get_clientdata()] and [sqlite3_set_clientdata()].
5987 */
5988 SQLITE_API void *sqlite3_get_auxdata(sqlite3_context*, int N);
5989 SQLITE_API void sqlite3_set_auxdata(sqlite3_context*, int N, void*, void (*)(void*));
5990
5991 /*
5992 ** CAPI3REF: Database Connection Client Data
5993 ** METHOD: sqlite3
5994 **
5995 ** These functions are used to associate one or more named pointers
5996 ** with a [database connection].
5997 ** A call to sqlite3_set_clientdata(D,N,P,X) causes the pointer P
5998 ** to be attached to [database connection] D using name N. Subsequent
5999 ** calls to sqlite3_get_clientdata(D,N) will return a copy of pointer P
6000 ** or a NULL pointer if there were no prior calls to
6001 ** sqlite3_set_clientdata() with the same values of D and N.
6002 ** Names are compared using strcmp() and are thus case sensitive.
6003 **
6004 ** If P and X are both non-NULL, then the destructor X is invoked with
6005 ** argument P on the first of the following occurrences:
6006 ** <ul>
6007 ** <li> An out-of-memory error occurs during the call to
6008 ** sqlite3_set_clientdata() which attempts to register pointer P.
6009 ** <li> A subsequent call to sqlite3_set_clientdata(D,N,P,X) is made
6010 ** with the same D and N parameters.
6011 ** <li> The database connection closes. SQLite does not make any guarantees
6012 ** about the order in which destructors are called, only that all
6013 ** destructors will be called exactly once at some point during the
6014 ** database connection closing process.
6015 ** </ul>
6016 **
6017 ** SQLite does not do anything with client data other than invoke
6018 ** destructors on the client data at the appropriate time. The intended
6019 ** use for client data is to provide a mechanism for wrapper libraries
6020 ** to store additional information about an SQLite database connection.
6021 **
6022 ** There is no limit (other than available memory) on the number of different
6023 ** client data pointers (with different names) that can be attached to a
6024 ** single database connection. However, the implementation is optimized
6025 ** for the case of having only one or two different client data names.
6026 ** Applications and wrapper libraries are discouraged from using more than
6027 ** one client data name each.
6028 **
6029 ** There is no way to enumerate the client data pointers
6030 ** associated with a database connection. The N parameter can be thought
6031 ** of as a secret key such that only code that knows the secret key is able
6032 ** to access the associated data.
6033 **
6034 ** Security Warning: These interfaces should not be exposed in scripting
6035 ** languages or in other circumstances where it might be possible for an
6036 ** an attacker to invoke them. Any agent that can invoke these interfaces
6037 ** can probably also take control of the process.
6038 **
6039 ** Database connection client data is only available for SQLite
6040 ** version 3.44.0 ([dateof:3.44.0]) and later.
6041 **
6042 ** See also: [sqlite3_set_auxdata()] and [sqlite3_get_auxdata()].
6043 */
6044 SQLITE_API void *sqlite3_get_clientdata(sqlite3*,const char*);
6045 SQLITE_API int sqlite3_set_clientdata(sqlite3*, const char*, void*, void(*)(void*));
6046
6047 /*
6048 ** CAPI3REF: Constants Defining Special Destructor Behavior
6049 **
6050 ** These are special values for the destructor that is passed in as the
6051 ** final argument to routines like [sqlite3_result_blob()]. ^If the destructor
6052 ** argument is SQLITE_STATIC, it means that the content pointer is constant
6053 ** and will never change. It does not need to be destroyed. ^The
6054 ** SQLITE_TRANSIENT value means that the content will likely change in
6055 ** the near future and that SQLite should make its own private copy of
6056 ** the content before returning.
6057 **
6058 ** The typedef is necessary to work around problems in certain
6059 ** C++ compilers.
6060 */
6061 typedef void (*sqlite3_destructor_type)(void*);
6062 #define SQLITE_STATIC ((sqlite3_destructor_type)0)
6063 #define SQLITE_TRANSIENT ((sqlite3_destructor_type)-1)
6064
6065 /*
6066 ** CAPI3REF: Setting The Result Of An SQL Function
6067 ** METHOD: sqlite3_context
6068 **
6069 ** These routines are used by the xFunc or xFinal callbacks that
6070 ** implement SQL functions and aggregates. See
6071 ** [sqlite3_create_function()] and [sqlite3_create_function16()]
6072 ** for additional information.
6073 **
6074 ** These functions work very much like the [parameter binding] family of
6075 ** functions used to bind values to host parameters in prepared statements.
6076 ** Refer to the [SQL parameter] documentation for additional information.
6077 **
6078 ** ^The sqlite3_result_blob() interface sets the result from
6079 ** an application-defined function to be the BLOB whose content is pointed
6080 ** to by the second parameter and which is N bytes long where N is the
6081 ** third parameter.
6082 **
6083 ** ^The sqlite3_result_zeroblob(C,N) and sqlite3_result_zeroblob64(C,N)
6084 ** interfaces set the result of the application-defined function to be
6085 ** a BLOB containing all zero bytes and N bytes in size.
6086 **
6087 ** ^The sqlite3_result_double() interface sets the result from
6088 ** an application-defined function to be a floating point value specified
6089 ** by its 2nd argument.
6090 **
6091 ** ^The sqlite3_result_error() and sqlite3_result_error16() functions
6092 ** cause the implemented SQL function to throw an exception.
6093 ** ^SQLite uses the string pointed to by the
6094 ** 2nd parameter of sqlite3_result_error() or sqlite3_result_error16()
6095 ** as the text of an error message. ^SQLite interprets the error
6096 ** message string from sqlite3_result_error() as UTF-8. ^SQLite
6097 ** interprets the string from sqlite3_result_error16() as UTF-16 using
6098 ** the same [byte-order determination rules] as [sqlite3_bind_text16()].
6099 ** ^If the third parameter to sqlite3_result_error()
6100 ** or sqlite3_result_error16() is negative then SQLite takes as the error
6101 ** message all text up through the first zero character.
6102 ** ^If the third parameter to sqlite3_result_error() or
6103 ** sqlite3_result_error16() is non-negative then SQLite takes that many
6104 ** bytes (not characters) from the 2nd parameter as the error message.
6105 ** ^The sqlite3_result_error() and sqlite3_result_error16()
6106 ** routines make a private copy of the error message text before
6107 ** they return. Hence, the calling function can deallocate or
6108 ** modify the text after they return without harm.
6109 ** ^The sqlite3_result_error_code() function changes the error code
6110 ** returned by SQLite as a result of an error in a function. ^By default,
6111 ** the error code is SQLITE_ERROR. ^A subsequent call to sqlite3_result_error()
6112 ** or sqlite3_result_error16() resets the error code to SQLITE_ERROR.
6113 **
6114 ** ^The sqlite3_result_error_toobig() interface causes SQLite to throw an
6115 ** error indicating that a string or BLOB is too long to represent.
6116 **
6117 ** ^The sqlite3_result_error_nomem() interface causes SQLite to throw an
6118 ** error indicating that a memory allocation failed.
6119 **
6120 ** ^The sqlite3_result_int() interface sets the return value
6121 ** of the application-defined function to be the 32-bit signed integer
6122 ** value given in the 2nd argument.
6123 ** ^The sqlite3_result_int64() interface sets the return value
6124 ** of the application-defined function to be the 64-bit signed integer
6125 ** value given in the 2nd argument.
6126 **
6127 ** ^The sqlite3_result_null() interface sets the return value
6128 ** of the application-defined function to be NULL.
6129 **
6130 ** ^The sqlite3_result_text(), sqlite3_result_text16(),
6131 ** sqlite3_result_text16le(), and sqlite3_result_text16be() interfaces
6132 ** set the return value of the application-defined function to be
6133 ** a text string which is represented as UTF-8, UTF-16 native byte order,
6134 ** UTF-16 little endian, or UTF-16 big endian, respectively.
6135 ** ^The sqlite3_result_text64() interface sets the return value of an
6136 ** application-defined function to be a text string in an encoding
6137 ** specified by the fifth (and last) parameter, which must be one
6138 ** of [SQLITE_UTF8], [SQLITE_UTF16], [SQLITE_UTF16BE], or [SQLITE_UTF16LE].
6139 ** ^SQLite takes the text result from the application from
6140 ** the 2nd parameter of the sqlite3_result_text* interfaces.
6141 ** ^If the 3rd parameter to any of the sqlite3_result_text* interfaces
6142 ** other than sqlite3_result_text64() is negative, then SQLite computes
6143 ** the string length itself by searching the 2nd parameter for the first
6144 ** zero character.
6145 ** ^If the 3rd parameter to the sqlite3_result_text* interfaces
6146 ** is non-negative, then as many bytes (not characters) of the text
6147 ** pointed to by the 2nd parameter are taken as the application-defined
6148 ** function result. If the 3rd parameter is non-negative, then it
6149 ** must be the byte offset into the string where the NUL terminator would
6150 ** appear if the string where NUL terminated. If any NUL characters occur
6151 ** in the string at a byte offset that is less than the value of the 3rd
6152 ** parameter, then the resulting string will contain embedded NULs and the
6153 ** result of expressions operating on strings with embedded NULs is undefined.
6154 ** ^If the 4th parameter to the sqlite3_result_text* interfaces
6155 ** or sqlite3_result_blob is a non-NULL pointer, then SQLite calls that
6156 ** function as the destructor on the text or BLOB result when it has
6157 ** finished using that result.
6158 ** ^If the 4th parameter to the sqlite3_result_text* interfaces or to
6159 ** sqlite3_result_blob is the special constant SQLITE_STATIC, then SQLite
6160 ** assumes that the text or BLOB result is in constant space and does not
6161 ** copy the content of the parameter nor call a destructor on the content
6162 ** when it has finished using that result.
6163 ** ^If the 4th parameter to the sqlite3_result_text* interfaces
6164 ** or sqlite3_result_blob is the special constant SQLITE_TRANSIENT
6165 ** then SQLite makes a copy of the result into space obtained
6166 ** from [sqlite3_malloc()] before it returns.
6167 **
6168 ** ^For the sqlite3_result_text16(), sqlite3_result_text16le(), and
6169 ** sqlite3_result_text16be() routines, and for sqlite3_result_text64()
6170 ** when the encoding is not UTF8, if the input UTF16 begins with a
6171 ** byte-order mark (BOM, U+FEFF) then the BOM is removed from the
6172 ** string and the rest of the string is interpreted according to the
6173 ** byte-order specified by the BOM. ^The byte-order specified by
6174 ** the BOM at the beginning of the text overrides the byte-order
6175 ** specified by the interface procedure. ^So, for example, if
6176 ** sqlite3_result_text16le() is invoked with text that begins
6177 ** with bytes 0xfe, 0xff (a big-endian byte-order mark) then the
6178 ** first two bytes of input are skipped and the remaining input
6179 ** is interpreted as UTF16BE text.
6180 **
6181 ** ^For UTF16 input text to the sqlite3_result_text16(),
6182 ** sqlite3_result_text16be(), sqlite3_result_text16le(), and
6183 ** sqlite3_result_text64() routines, if the text contains invalid
6184 ** UTF16 characters, the invalid characters might be converted
6185 ** into the unicode replacement character, U+FFFD.
6186 **
6187 ** ^The sqlite3_result_value() interface sets the result of
6188 ** the application-defined function to be a copy of the
6189 ** [unprotected sqlite3_value] object specified by the 2nd parameter. ^The
6190 ** sqlite3_result_value() interface makes a copy of the [sqlite3_value]
6191 ** so that the [sqlite3_value] specified in the parameter may change or
6192 ** be deallocated after sqlite3_result_value() returns without harm.
6193 ** ^A [protected sqlite3_value] object may always be used where an
6194 ** [unprotected sqlite3_value] object is required, so either
6195 ** kind of [sqlite3_value] object can be used with this interface.
6196 **
6197 ** ^The sqlite3_result_pointer(C,P,T,D) interface sets the result to an
6198 ** SQL NULL value, just like [sqlite3_result_null(C)], except that it
6199 ** also associates the host-language pointer P or type T with that
6200 ** NULL value such that the pointer can be retrieved within an
6201 ** [application-defined SQL function] using [sqlite3_value_pointer()].
6202 ** ^If the D parameter is not NULL, then it is a pointer to a destructor
6203 ** for the P parameter. ^SQLite invokes D with P as its only argument
6204 ** when SQLite is finished with P. The T parameter should be a static
6205 ** string and preferably a string literal. The sqlite3_result_pointer()
6206 ** routine is part of the [pointer passing interface] added for SQLite 3.20.0.
6207 **
6208 ** If these routines are called from within the different thread
6209 ** than the one containing the application-defined function that received
6210 ** the [sqlite3_context] pointer, the results are undefined.
6211 */
6212 SQLITE_API void sqlite3_result_blob(sqlite3_context*, const void*, int, void(*)(void*));
6213 SQLITE_API void sqlite3_result_blob64(sqlite3_context*,const void*,
6214 sqlite3_uint64,void(*)(void*));
6215 SQLITE_API void sqlite3_result_double(sqlite3_context*, double);
6216 SQLITE_API void sqlite3_result_error(sqlite3_context*, const char*, int);
6217 SQLITE_API void sqlite3_result_error16(sqlite3_context*, const void*, int);
6218 SQLITE_API void sqlite3_result_error_toobig(sqlite3_context*);
6219 SQLITE_API void sqlite3_result_error_nomem(sqlite3_context*);
6220 SQLITE_API void sqlite3_result_error_code(sqlite3_context*, int);
6221 SQLITE_API void sqlite3_result_int(sqlite3_context*, int);
6222 SQLITE_API void sqlite3_result_int64(sqlite3_context*, sqlite3_int64);
6223 SQLITE_API void sqlite3_result_null(sqlite3_context*);
6224 SQLITE_API void sqlite3_result_text(sqlite3_context*, const char*, int, void(*)(void*));
6225 SQLITE_API void sqlite3_result_text64(sqlite3_context*, const char*,sqlite3_uint64,
6226 void(*)(void*), unsigned char encoding);
6227 SQLITE_API void sqlite3_result_text16(sqlite3_context*, const void*, int, void(*)(void*));
6228 SQLITE_API void sqlite3_result_text16le(sqlite3_context*, const void*, int,void(*)(void*));
6229 SQLITE_API void sqlite3_result_text16be(sqlite3_context*, const void*, int,void(*)(void*));
6230 SQLITE_API void sqlite3_result_value(sqlite3_context*, sqlite3_value*);
6231 SQLITE_API void sqlite3_result_pointer(sqlite3_context*, void*,const char*,void(*)(void*));
6232 SQLITE_API void sqlite3_result_zeroblob(sqlite3_context*, int n);
6233 SQLITE_API int sqlite3_result_zeroblob64(sqlite3_context*, sqlite3_uint64 n);
6234
6235
6236 /*
6237 ** CAPI3REF: Setting The Subtype Of An SQL Function
6238 ** METHOD: sqlite3_context
6239 **
6240 ** The sqlite3_result_subtype(C,T) function causes the subtype of
6241 ** the result from the [application-defined SQL function] with
6242 ** [sqlite3_context] C to be the value T. Only the lower 8 bits
6243 ** of the subtype T are preserved in current versions of SQLite;
6244 ** higher order bits are discarded.
6245 ** The number of subtype bytes preserved by SQLite might increase
6246 ** in future releases of SQLite.
6247 **
6248 ** Every [application-defined SQL function] that invokes this interface
6249 ** should include the [SQLITE_RESULT_SUBTYPE] property in its
6250 ** text encoding argument when the SQL function is
6251 ** [sqlite3_create_function|registered]. If the [SQLITE_RESULT_SUBTYPE]
6252 ** property is omitted from the function that invokes sqlite3_result_subtype(),
6253 ** then in some cases the sqlite3_result_subtype() might fail to set
6254 ** the result subtype.
6255 **
6256 ** If SQLite is compiled with -DSQLITE_STRICT_SUBTYPE=1, then any
6257 ** SQL function that invokes the sqlite3_result_subtype() interface
6258 ** and that does not have the SQLITE_RESULT_SUBTYPE property will raise
6259 ** an error. Future versions of SQLite might enable -DSQLITE_STRICT_SUBTYPE=1
6260 ** by default.
6261 */
6262 SQLITE_API void sqlite3_result_subtype(sqlite3_context*,unsigned int);
6263
6264 /*
6265 ** CAPI3REF: Define New Collating Sequences
6266 ** METHOD: sqlite3
6267 **
6268 ** ^These functions add, remove, or modify a [collation] associated
6269 ** with the [database connection] specified as the first argument.
6270 **
6271 ** ^The name of the collation is a UTF-8 string
6272 ** for sqlite3_create_collation() and sqlite3_create_collation_v2()
6273 ** and a UTF-16 string in native byte order for sqlite3_create_collation16().
6274 ** ^Collation names that compare equal according to [sqlite3_strnicmp()] are
6275 ** considered to be the same name.
6276 **
6277 ** ^(The third argument (eTextRep) must be one of the constants:
6278 ** <ul>
6279 ** <li> [SQLITE_UTF8],
6280 ** <li> [SQLITE_UTF16LE],
6281 ** <li> [SQLITE_UTF16BE],
6282 ** <li> [SQLITE_UTF16], or
6283 ** <li> [SQLITE_UTF16_ALIGNED].
6284 ** </ul>)^
6285 ** ^The eTextRep argument determines the encoding of strings passed
6286 ** to the collating function callback, xCompare.
6287 ** ^The [SQLITE_UTF16] and [SQLITE_UTF16_ALIGNED] values for eTextRep
6288 ** force strings to be UTF16 with native byte order.
6289 ** ^The [SQLITE_UTF16_ALIGNED] value for eTextRep forces strings to begin
6290 ** on an even byte address.
6291 **
6292 ** ^The fourth argument, pArg, is an application data pointer that is passed
6293 ** through as the first argument to the collating function callback.
6294 **
6295 ** ^The fifth argument, xCompare, is a pointer to the collating function.
6296 ** ^Multiple collating functions can be registered using the same name but
6297 ** with different eTextRep parameters and SQLite will use whichever
6298 ** function requires the least amount of data transformation.
6299 ** ^If the xCompare argument is NULL then the collating function is
6300 ** deleted. ^When all collating functions having the same name are deleted,
6301 ** that collation is no longer usable.
6302 **
6303 ** ^The collating function callback is invoked with a copy of the pArg
6304 ** application data pointer and with two strings in the encoding specified
6305 ** by the eTextRep argument. The two integer parameters to the collating
6306 ** function callback are the length of the two strings, in bytes. The collating
6307 ** function must return an integer that is negative, zero, or positive
6308 ** if the first string is less than, equal to, or greater than the second,
6309 ** respectively. A collating function must always return the same answer
6310 ** given the same inputs. If two or more collating functions are registered
6311 ** to the same collation name (using different eTextRep values) then all
6312 ** must give an equivalent answer when invoked with equivalent strings.
6313 ** The collating function must obey the following properties for all
6314 ** strings A, B, and C:
6315 **
6316 ** <ol>
6317 ** <li> If A==B then B==A.
6318 ** <li> If A==B and B==C then A==C.
6319 ** <li> If A&lt;B THEN B&gt;A.
6320 ** <li> If A&lt;B and B&lt;C then A&lt;C.
6321 ** </ol>
6322 **
6323 ** If a collating function fails any of the above constraints and that
6324 ** collating function is registered and used, then the behavior of SQLite
6325 ** is undefined.
6326 **
6327 ** ^The sqlite3_create_collation_v2() works like sqlite3_create_collation()
6328 ** with the addition that the xDestroy callback is invoked on pArg when
6329 ** the collating function is deleted.
6330 ** ^Collating functions are deleted when they are overridden by later
6331 ** calls to the collation creation functions or when the
6332 ** [database connection] is closed using [sqlite3_close()].
6333 **
6334 ** ^The xDestroy callback is <u>not</u> called if the
6335 ** sqlite3_create_collation_v2() function fails. Applications that invoke
6336 ** sqlite3_create_collation_v2() with a non-NULL xDestroy argument should
6337 ** check the return code and dispose of the application data pointer
6338 ** themselves rather than expecting SQLite to deal with it for them.
6339 ** This is different from every other SQLite interface. The inconsistency
6340 ** is unfortunate but cannot be changed without breaking backwards
6341 ** compatibility.
6342 **
6343 ** See also: [sqlite3_collation_needed()] and [sqlite3_collation_needed16()].
6344 */
6345 SQLITE_API int sqlite3_create_collation(
6346 sqlite3*,
6347 const char *zName,
6348 int eTextRep,
6349 void *pArg,
6350 int(*xCompare)(void*,int,const void*,int,const void*)
6351 );
6352 SQLITE_API int sqlite3_create_collation_v2(
6353 sqlite3*,
6354 const char *zName,
6355 int eTextRep,
6356 void *pArg,
6357 int(*xCompare)(void*,int,const void*,int,const void*),
6358 void(*xDestroy)(void*)
6359 );
6360 SQLITE_API int sqlite3_create_collation16(
6361 sqlite3*,
6362 const void *zName,
6363 int eTextRep,
6364 void *pArg,
6365 int(*xCompare)(void*,int,const void*,int,const void*)
6366 );
6367
6368 /*
6369 ** CAPI3REF: Collation Needed Callbacks
6370 ** METHOD: sqlite3
6371 **
6372 ** ^To avoid having to register all collation sequences before a database
6373 ** can be used, a single callback function may be registered with the
6374 ** [database connection] to be invoked whenever an undefined collation
6375 ** sequence is required.
6376 **
6377 ** ^If the function is registered using the sqlite3_collation_needed() API,
6378 ** then it is passed the names of undefined collation sequences as strings
6379 ** encoded in UTF-8. ^If sqlite3_collation_needed16() is used,
6380 ** the names are passed as UTF-16 in machine native byte order.
6381 ** ^A call to either function replaces the existing collation-needed callback.
6382 **
6383 ** ^(When the callback is invoked, the first argument passed is a copy
6384 ** of the second argument to sqlite3_collation_needed() or
6385 ** sqlite3_collation_needed16(). The second argument is the database
6386 ** connection. The third argument is one of [SQLITE_UTF8], [SQLITE_UTF16BE],
6387 ** or [SQLITE_UTF16LE], indicating the most desirable form of the collation
6388 ** sequence function required. The fourth parameter is the name of the
6389 ** required collation sequence.)^
6390 **
6391 ** The callback function should register the desired collation using
6392 ** [sqlite3_create_collation()], [sqlite3_create_collation16()], or
6393 ** [sqlite3_create_collation_v2()].
6394 */
6395 SQLITE_API int sqlite3_collation_needed(
6396 sqlite3*,
6397 void*,
6398 void(*)(void*,sqlite3*,int eTextRep,const char*)
6399 );
6400 SQLITE_API int sqlite3_collation_needed16(
6401 sqlite3*,
6402 void*,
6403 void(*)(void*,sqlite3*,int eTextRep,const void*)
6404 );
6405
6406 #ifdef SQLITE_ENABLE_CEROD
6407 /*
6408 ** Specify the activation key for a CEROD database. Unless
6409 ** activated, none of the CEROD routines will work.
6410 */
6411 SQLITE_API void sqlite3_activate_cerod(
6412 const char *zPassPhrase /* Activation phrase */
6413 );
6414 #endif
6415
6416 /*
6417 ** CAPI3REF: Suspend Execution For A Short Time
6418 **
6419 ** The sqlite3_sleep() function causes the current thread to suspend execution
6420 ** for at least a number of milliseconds specified in its parameter.
6421 **
6422 ** If the operating system does not support sleep requests with
6423 ** millisecond time resolution, then the time will be rounded up to
6424 ** the nearest second. The number of milliseconds of sleep actually
6425 ** requested from the operating system is returned.
6426 **
6427 ** ^SQLite implements this interface by calling the xSleep()
6428 ** method of the default [sqlite3_vfs] object. If the xSleep() method
6429 ** of the default VFS is not implemented correctly, or not implemented at
6430 ** all, then the behavior of sqlite3_sleep() may deviate from the description
6431 ** in the previous paragraphs.
6432 **
6433 ** If a negative argument is passed to sqlite3_sleep() the results vary by
6434 ** VFS and operating system. Some system treat a negative argument as an
6435 ** instruction to sleep forever. Others understand it to mean do not sleep
6436 ** at all. ^In SQLite version 3.42.0 and later, a negative
6437 ** argument passed into sqlite3_sleep() is changed to zero before it is relayed
6438 ** down into the xSleep method of the VFS.
6439 */
6440 SQLITE_API int sqlite3_sleep(int);
6441
6442 /*
6443 ** CAPI3REF: Name Of The Folder Holding Temporary Files
6444 **
6445 ** ^(If this global variable is made to point to a string which is
6446 ** the name of a folder (a.k.a. directory), then all temporary files
6447 ** created by SQLite when using a built-in [sqlite3_vfs | VFS]
6448 ** will be placed in that directory.)^ ^If this variable
6449 ** is a NULL pointer, then SQLite performs a search for an appropriate
6450 ** temporary file directory.
6451 **
6452 ** Applications are strongly discouraged from using this global variable.
6453 ** It is required to set a temporary folder on Windows Runtime (WinRT).
6454 ** But for all other platforms, it is highly recommended that applications
6455 ** neither read nor write this variable. This global variable is a relic
6456 ** that exists for backwards compatibility of legacy applications and should
6457 ** be avoided in new projects.
6458 **
6459 ** It is not safe to read or modify this variable in more than one
6460 ** thread at a time. It is not safe to read or modify this variable
6461 ** if a [database connection] is being used at the same time in a separate
6462 ** thread.
6463 ** It is intended that this variable be set once
6464 ** as part of process initialization and before any SQLite interface
6465 ** routines have been called and that this variable remain unchanged
6466 ** thereafter.
6467 **
6468 ** ^The [temp_store_directory pragma] may modify this variable and cause
6469 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
6470 ** the [temp_store_directory pragma] always assumes that any string
6471 ** that this variable points to is held in memory obtained from
6472 ** [sqlite3_malloc] and the pragma may attempt to free that memory
6473 ** using [sqlite3_free].
6474 ** Hence, if this variable is modified directly, either it should be
6475 ** made NULL or made to point to memory obtained from [sqlite3_malloc]
6476 ** or else the use of the [temp_store_directory pragma] should be avoided.
6477 ** Except when requested by the [temp_store_directory pragma], SQLite
6478 ** does not free the memory that sqlite3_temp_directory points to. If
6479 ** the application wants that memory to be freed, it must do
6480 ** so itself, taking care to only do so after all [database connection]
6481 ** objects have been destroyed.
6482 **
6483 ** <b>Note to Windows Runtime users:</b> The temporary directory must be set
6484 ** prior to calling [sqlite3_open] or [sqlite3_open_v2]. Otherwise, various
6485 ** features that require the use of temporary files may fail. Here is an
6486 ** example of how to do this using C++ with the Windows Runtime:
6487 **
6488 ** <blockquote><pre>
6489 ** LPCWSTR zPath = Windows::Storage::ApplicationData::Current->
6490 ** &nbsp; TemporaryFolder->Path->Data();
6491 ** char zPathBuf&#91;MAX_PATH + 1&#93;;
6492 ** memset(zPathBuf, 0, sizeof(zPathBuf));
6493 ** WideCharToMultiByte(CP_UTF8, 0, zPath, -1, zPathBuf, sizeof(zPathBuf),
6494 ** &nbsp; NULL, NULL);
6495 ** sqlite3_temp_directory = sqlite3_mprintf("%s", zPathBuf);
6496 ** </pre></blockquote>
6497 */
6498 SQLITE_API SQLITE_EXTERN char *sqlite3_temp_directory;
6499
6500 /*
6501 ** CAPI3REF: Name Of The Folder Holding Database Files
6502 **
6503 ** ^(If this global variable is made to point to a string which is
6504 ** the name of a folder (a.k.a. directory), then all database files
6505 ** specified with a relative pathname and created or accessed by
6506 ** SQLite when using a built-in windows [sqlite3_vfs | VFS] will be assumed
6507 ** to be relative to that directory.)^ ^If this variable is a NULL
6508 ** pointer, then SQLite assumes that all database files specified
6509 ** with a relative pathname are relative to the current directory
6510 ** for the process. Only the windows VFS makes use of this global
6511 ** variable; it is ignored by the unix VFS.
6512 **
6513 ** Changing the value of this variable while a database connection is
6514 ** open can result in a corrupt database.
6515 **
6516 ** It is not safe to read or modify this variable in more than one
6517 ** thread at a time. It is not safe to read or modify this variable
6518 ** if a [database connection] is being used at the same time in a separate
6519 ** thread.
6520 ** It is intended that this variable be set once
6521 ** as part of process initialization and before any SQLite interface
6522 ** routines have been called and that this variable remain unchanged
6523 ** thereafter.
6524 **
6525 ** ^The [data_store_directory pragma] may modify this variable and cause
6526 ** it to point to memory obtained from [sqlite3_malloc]. ^Furthermore,
6527 ** the [data_store_directory pragma] always assumes that any string
6528 ** that this variable points to is held in memory obtained from
6529 ** [sqlite3_malloc] and the pragma may attempt to free that memory
6530 ** using [sqlite3_free].
6531 ** Hence, if this variable is modified directly, either it should be
6532 ** made NULL or made to point to memory obtained from [sqlite3_malloc]
6533 ** or else the use of the [data_store_directory pragma] should be avoided.
6534 */
6535 SQLITE_API SQLITE_EXTERN char *sqlite3_data_directory;
6536
6537 /*
6538 ** CAPI3REF: Win32 Specific Interface
6539 **
6540 ** These interfaces are available only on Windows. The
6541 ** [sqlite3_win32_set_directory] interface is used to set the value associated
6542 ** with the [sqlite3_temp_directory] or [sqlite3_data_directory] variable, to
6543 ** zValue, depending on the value of the type parameter. The zValue parameter
6544 ** should be NULL to cause the previous value to be freed via [sqlite3_free];
6545 ** a non-NULL value will be copied into memory obtained from [sqlite3_malloc]
6546 ** prior to being used. The [sqlite3_win32_set_directory] interface returns
6547 ** [SQLITE_OK] to indicate success, [SQLITE_ERROR] if the type is unsupported,
6548 ** or [SQLITE_NOMEM] if memory could not be allocated. The value of the
6549 ** [sqlite3_data_directory] variable is intended to act as a replacement for
6550 ** the current directory on the sub-platforms of Win32 where that concept is
6551 ** not present, e.g. WinRT and UWP. The [sqlite3_win32_set_directory8] and
6552 ** [sqlite3_win32_set_directory16] interfaces behave exactly the same as the
6553 ** sqlite3_win32_set_directory interface except the string parameter must be
6554 ** UTF-8 or UTF-16, respectively.
6555 */
6556 SQLITE_API int sqlite3_win32_set_directory(
6557 unsigned long type, /* Identifier for directory being set or reset */
6558 void *zValue /* New value for directory being set or reset */
6559 );
6560 SQLITE_API int sqlite3_win32_set_directory8(unsigned long type, const char *zValue);
6561 SQLITE_API int sqlite3_win32_set_directory16(unsigned long type, const void *zValue);
6562
6563 /*
6564 ** CAPI3REF: Win32 Directory Types
6565 **
6566 ** These macros are only available on Windows. They define the allowed values
6567 ** for the type argument to the [sqlite3_win32_set_directory] interface.
6568 */
6569 #define SQLITE_WIN32_DATA_DIRECTORY_TYPE 1
6570 #define SQLITE_WIN32_TEMP_DIRECTORY_TYPE 2
6571
6572 /*
6573 ** CAPI3REF: Test For Auto-Commit Mode
6574 ** KEYWORDS: {autocommit mode}
6575 ** METHOD: sqlite3
6576 **
6577 ** ^The sqlite3_get_autocommit() interface returns non-zero or
6578 ** zero if the given database connection is or is not in autocommit mode,
6579 ** respectively. ^Autocommit mode is on by default.
6580 ** ^Autocommit mode is disabled by a [BEGIN] statement.
6581 ** ^Autocommit mode is re-enabled by a [COMMIT] or [ROLLBACK].
6582 **
6583 ** If certain kinds of errors occur on a statement within a multi-statement
6584 ** transaction (errors including [SQLITE_FULL], [SQLITE_IOERR],
6585 ** [SQLITE_NOMEM], [SQLITE_BUSY], and [SQLITE_INTERRUPT]) then the
6586 ** transaction might be rolled back automatically. The only way to
6587 ** find out whether SQLite automatically rolled back the transaction after
6588 ** an error is to use this function.
6589 **
6590 ** If another thread changes the autocommit status of the database
6591 ** connection while this routine is running, then the return value
6592 ** is undefined.
6593 */
6594 SQLITE_API int sqlite3_get_autocommit(sqlite3*);
6595
6596 /*
6597 ** CAPI3REF: Find The Database Handle Of A Prepared Statement
6598 ** METHOD: sqlite3_stmt
6599 **
6600 ** ^The sqlite3_db_handle interface returns the [database connection] handle
6601 ** to which a [prepared statement] belongs. ^The [database connection]
6602 ** returned by sqlite3_db_handle is the same [database connection]
6603 ** that was the first argument
6604 ** to the [sqlite3_prepare_v2()] call (or its variants) that was used to
6605 ** create the statement in the first place.
6606 */
6607 SQLITE_API sqlite3 *sqlite3_db_handle(sqlite3_stmt*);
6608
6609 /*
6610 ** CAPI3REF: Return The Schema Name For A Database Connection
6611 ** METHOD: sqlite3
6612 **
6613 ** ^The sqlite3_db_name(D,N) interface returns a pointer to the schema name
6614 ** for the N-th database on database connection D, or a NULL pointer of N is
6615 ** out of range. An N value of 0 means the main database file. An N of 1 is
6616 ** the "temp" schema. Larger values of N correspond to various ATTACH-ed
6617 ** databases.
6618 **
6619 ** Space to hold the string that is returned by sqlite3_db_name() is managed
6620 ** by SQLite itself. The string might be deallocated by any operation that
6621 ** changes the schema, including [ATTACH] or [DETACH] or calls to
6622 ** [sqlite3_serialize()] or [sqlite3_deserialize()], even operations that
6623 ** occur on a different thread. Applications that need to
6624 ** remember the string long-term should make their own copy. Applications that
6625 ** are accessing the same database connection simultaneously on multiple
6626 ** threads should mutex-protect calls to this API and should make their own
6627 ** private copy of the result prior to releasing the mutex.
6628 */
6629 SQLITE_API const char *sqlite3_db_name(sqlite3 *db, int N);
6630
6631 /*
6632 ** CAPI3REF: Return The Filename For A Database Connection
6633 ** METHOD: sqlite3
6634 **
6635 ** ^The sqlite3_db_filename(D,N) interface returns a pointer to the filename
6636 ** associated with database N of connection D.
6637 ** ^If there is no attached database N on the database
6638 ** connection D, or if database N is a temporary or in-memory database, then
6639 ** this function will return either a NULL pointer or an empty string.
6640 **
6641 ** ^The string value returned by this routine is owned and managed by
6642 ** the database connection. ^The value will be valid until the database N
6643 ** is [DETACH]-ed or until the database connection closes.
6644 **
6645 ** ^The filename returned by this function is the output of the
6646 ** xFullPathname method of the [VFS]. ^In other words, the filename
6647 ** will be an absolute pathname, even if the filename used
6648 ** to open the database originally was a URI or relative pathname.
6649 **
6650 ** If the filename pointer returned by this routine is not NULL, then it
6651 ** can be used as the filename input parameter to these routines:
6652 ** <ul>
6653 ** <li> [sqlite3_uri_parameter()]
6654 ** <li> [sqlite3_uri_boolean()]
6655 ** <li> [sqlite3_uri_int64()]
6656 ** <li> [sqlite3_filename_database()]
6657 ** <li> [sqlite3_filename_journal()]
6658 ** <li> [sqlite3_filename_wal()]
6659 ** </ul>
6660 */
6661 SQLITE_API sqlite3_filename sqlite3_db_filename(sqlite3 *db, const char *zDbName);
6662
6663 /*
6664 ** CAPI3REF: Determine if a database is read-only
6665 ** METHOD: sqlite3
6666 **
6667 ** ^The sqlite3_db_readonly(D,N) interface returns 1 if the database N
6668 ** of connection D is read-only, 0 if it is read/write, or -1 if N is not
6669 ** the name of a database on connection D.
6670 */
6671 SQLITE_API int sqlite3_db_readonly(sqlite3 *db, const char *zDbName);
6672
6673 /*
6674 ** CAPI3REF: Determine the transaction state of a database
6675 ** METHOD: sqlite3
6676 **
6677 ** ^The sqlite3_txn_state(D,S) interface returns the current
6678 ** [transaction state] of schema S in database connection D. ^If S is NULL,
6679 ** then the highest transaction state of any schema on database connection D
6680 ** is returned. Transaction states are (in order of lowest to highest):
6681 ** <ol>
6682 ** <li value="0"> SQLITE_TXN_NONE
6683 ** <li value="1"> SQLITE_TXN_READ
6684 ** <li value="2"> SQLITE_TXN_WRITE
6685 ** </ol>
6686 ** ^If the S argument to sqlite3_txn_state(D,S) is not the name of
6687 ** a valid schema, then -1 is returned.
6688 */
6689 SQLITE_API int sqlite3_txn_state(sqlite3*,const char *zSchema);
6690
6691 /*
6692 ** CAPI3REF: Allowed return values from sqlite3_txn_state()
6693 ** KEYWORDS: {transaction state}
6694 **
6695 ** These constants define the current transaction state of a database file.
6696 ** ^The [sqlite3_txn_state(D,S)] interface returns one of these
6697 ** constants in order to describe the transaction state of schema S
6698 ** in [database connection] D.
6699 **
6700 ** <dl>
6701 ** [[SQLITE_TXN_NONE]] <dt>SQLITE_TXN_NONE</dt>
6702 ** <dd>The SQLITE_TXN_NONE state means that no transaction is currently
6703 ** pending.</dd>
6704 **
6705 ** [[SQLITE_TXN_READ]] <dt>SQLITE_TXN_READ</dt>
6706 ** <dd>The SQLITE_TXN_READ state means that the database is currently
6707 ** in a read transaction. Content has been read from the database file
6708 ** but nothing in the database file has changed. The transaction state
6709 ** will advanced to SQLITE_TXN_WRITE if any changes occur and there are
6710 ** no other conflicting concurrent write transactions. The transaction
6711 ** state will revert to SQLITE_TXN_NONE following a [ROLLBACK] or
6712 ** [COMMIT].</dd>
6713 **
6714 ** [[SQLITE_TXN_WRITE]] <dt>SQLITE_TXN_WRITE</dt>
6715 ** <dd>The SQLITE_TXN_WRITE state means that the database is currently
6716 ** in a write transaction. Content has been written to the database file
6717 ** but has not yet committed. The transaction state will change to
6718 ** to SQLITE_TXN_NONE at the next [ROLLBACK] or [COMMIT].</dd>
6719 */
6720 #define SQLITE_TXN_NONE 0
6721 #define SQLITE_TXN_READ 1
6722 #define SQLITE_TXN_WRITE 2
6723
6724 /*
6725 ** CAPI3REF: Find the next prepared statement
6726 ** METHOD: sqlite3
6727 **
6728 ** ^This interface returns a pointer to the next [prepared statement] after
6729 ** pStmt associated with the [database connection] pDb. ^If pStmt is NULL
6730 ** then this interface returns a pointer to the first prepared statement
6731 ** associated with the database connection pDb. ^If no prepared statement
6732 ** satisfies the conditions of this routine, it returns NULL.
6733 **
6734 ** The [database connection] pointer D in a call to
6735 ** [sqlite3_next_stmt(D,S)] must refer to an open database
6736 ** connection and in particular must not be a NULL pointer.
6737 */
6738 SQLITE_API sqlite3_stmt *sqlite3_next_stmt(sqlite3 *pDb, sqlite3_stmt *pStmt);
6739
6740 /*
6741 ** CAPI3REF: Commit And Rollback Notification Callbacks
6742 ** METHOD: sqlite3
6743 **
6744 ** ^The sqlite3_commit_hook() interface registers a callback
6745 ** function to be invoked whenever a transaction is [COMMIT | committed].
6746 ** ^Any callback set by a previous call to sqlite3_commit_hook()
6747 ** for the same database connection is overridden.
6748 ** ^The sqlite3_rollback_hook() interface registers a callback
6749 ** function to be invoked whenever a transaction is [ROLLBACK | rolled back].
6750 ** ^Any callback set by a previous call to sqlite3_rollback_hook()
6751 ** for the same database connection is overridden.
6752 ** ^The pArg argument is passed through to the callback.
6753 ** ^If the callback on a commit hook function returns non-zero,
6754 ** then the commit is converted into a rollback.
6755 **
6756 ** ^The sqlite3_commit_hook(D,C,P) and sqlite3_rollback_hook(D,C,P) functions
6757 ** return the P argument from the previous call of the same function
6758 ** on the same [database connection] D, or NULL for
6759 ** the first call for each function on D.
6760 **
6761 ** The commit and rollback hook callbacks are not reentrant.
6762 ** The callback implementation must not do anything that will modify
6763 ** the database connection that invoked the callback. Any actions
6764 ** to modify the database connection must be deferred until after the
6765 ** completion of the [sqlite3_step()] call that triggered the commit
6766 ** or rollback hook in the first place.
6767 ** Note that running any other SQL statements, including SELECT statements,
6768 ** or merely calling [sqlite3_prepare_v2()] and [sqlite3_step()] will modify
6769 ** the database connections for the meaning of "modify" in this paragraph.
6770 **
6771 ** ^Registering a NULL function disables the callback.
6772 **
6773 ** ^When the commit hook callback routine returns zero, the [COMMIT]
6774 ** operation is allowed to continue normally. ^If the commit hook
6775 ** returns non-zero, then the [COMMIT] is converted into a [ROLLBACK].
6776 ** ^The rollback hook is invoked on a rollback that results from a commit
6777 ** hook returning non-zero, just as it would be with any other rollback.
6778 **
6779 ** ^For the purposes of this API, a transaction is said to have been
6780 ** rolled back if an explicit "ROLLBACK" statement is executed, or
6781 ** an error or constraint causes an implicit rollback to occur.
6782 ** ^The rollback callback is not invoked if a transaction is
6783 ** automatically rolled back because the database connection is closed.
6784 **
6785 ** See also the [sqlite3_update_hook()] interface.
6786 */
6787 SQLITE_API void *sqlite3_commit_hook(sqlite3*, int(*)(void*), void*);
6788 SQLITE_API void *sqlite3_rollback_hook(sqlite3*, void(*)(void *), void*);
6789
6790 /*
6791 ** CAPI3REF: Autovacuum Compaction Amount Callback
6792 ** METHOD: sqlite3
6793 **
6794 ** ^The sqlite3_autovacuum_pages(D,C,P,X) interface registers a callback
6795 ** function C that is invoked prior to each autovacuum of the database
6796 ** file. ^The callback is passed a copy of the generic data pointer (P),
6797 ** the schema-name of the attached database that is being autovacuumed,
6798 ** the size of the database file in pages, the number of free pages,
6799 ** and the number of bytes per page, respectively. The callback should
6800 ** return the number of free pages that should be removed by the
6801 ** autovacuum. ^If the callback returns zero, then no autovacuum happens.
6802 ** ^If the value returned is greater than or equal to the number of
6803 ** free pages, then a complete autovacuum happens.
6804 **
6805 ** <p>^If there are multiple ATTACH-ed database files that are being
6806 ** modified as part of a transaction commit, then the autovacuum pages
6807 ** callback is invoked separately for each file.
6808 **
6809 ** <p><b>The callback is not reentrant.</b> The callback function should
6810 ** not attempt to invoke any other SQLite interface. If it does, bad
6811 ** things may happen, including segmentation faults and corrupt database
6812 ** files. The callback function should be a simple function that
6813 ** does some arithmetic on its input parameters and returns a result.
6814 **
6815 ** ^The X parameter to sqlite3_autovacuum_pages(D,C,P,X) is an optional
6816 ** destructor for the P parameter. ^If X is not NULL, then X(P) is
6817 ** invoked whenever the database connection closes or when the callback
6818 ** is overwritten by another invocation of sqlite3_autovacuum_pages().
6819 **
6820 ** <p>^There is only one autovacuum pages callback per database connection.
6821 ** ^Each call to the sqlite3_autovacuum_pages() interface overrides all
6822 ** previous invocations for that database connection. ^If the callback
6823 ** argument (C) to sqlite3_autovacuum_pages(D,C,P,X) is a NULL pointer,
6824 ** then the autovacuum steps callback is canceled. The return value
6825 ** from sqlite3_autovacuum_pages() is normally SQLITE_OK, but might
6826 ** be some other error code if something goes wrong. The current
6827 ** implementation will only return SQLITE_OK or SQLITE_MISUSE, but other
6828 ** return codes might be added in future releases.
6829 **
6830 ** <p>If no autovacuum pages callback is specified (the usual case) or
6831 ** a NULL pointer is provided for the callback,
6832 ** then the default behavior is to vacuum all free pages. So, in other
6833 ** words, the default behavior is the same as if the callback function
6834 ** were something like this:
6835 **
6836 ** <blockquote><pre>
6837 ** &nbsp; unsigned int demonstration_autovac_pages_callback(
6838 ** &nbsp; void *pClientData,
6839 ** &nbsp; const char *zSchema,
6840 ** &nbsp; unsigned int nDbPage,
6841 ** &nbsp; unsigned int nFreePage,
6842 ** &nbsp; unsigned int nBytePerPage
6843 ** &nbsp; ){
6844 ** &nbsp; return nFreePage;
6845 ** &nbsp; }
6846 ** </pre></blockquote>
6847 */
6848 SQLITE_API int sqlite3_autovacuum_pages(
6849 sqlite3 *db,
6850 unsigned int(*)(void*,const char*,unsigned int,unsigned int,unsigned int),
6851 void*,
6852 void(*)(void*)
6853 );
6854
6855
6856 /*
6857 ** CAPI3REF: Data Change Notification Callbacks
6858 ** METHOD: sqlite3
6859 **
6860 ** ^The sqlite3_update_hook() interface registers a callback function
6861 ** with the [database connection] identified by the first argument
6862 ** to be invoked whenever a row is updated, inserted or deleted in
6863 ** a [rowid table].
6864 ** ^Any callback set by a previous call to this function
6865 ** for the same database connection is overridden.
6866 **
6867 ** ^The second argument is a pointer to the function to invoke when a
6868 ** row is updated, inserted or deleted in a rowid table.
6869 ** ^The first argument to the callback is a copy of the third argument
6870 ** to sqlite3_update_hook().
6871 ** ^The second callback argument is one of [SQLITE_INSERT], [SQLITE_DELETE],
6872 ** or [SQLITE_UPDATE], depending on the operation that caused the callback
6873 ** to be invoked.
6874 ** ^The third and fourth arguments to the callback contain pointers to the
6875 ** database and table name containing the affected row.
6876 ** ^The final callback parameter is the [rowid] of the row.
6877 ** ^In the case of an update, this is the [rowid] after the update takes place.
6878 **
6879 ** ^(The update hook is not invoked when internal system tables are
6880 ** modified (i.e. sqlite_sequence).)^
6881 ** ^The update hook is not invoked when [WITHOUT ROWID] tables are modified.
6882 **
6883 ** ^In the current implementation, the update hook
6884 ** is not invoked when conflicting rows are deleted because of an
6885 ** [ON CONFLICT | ON CONFLICT REPLACE] clause. ^Nor is the update hook
6886 ** invoked when rows are deleted using the [truncate optimization].
6887 ** The exceptions defined in this paragraph might change in a future
6888 ** release of SQLite.
6889 **
6890 ** Whether the update hook is invoked before or after the
6891 ** corresponding change is currently unspecified and may differ
6892 ** depending on the type of change. Do not rely on the order of the
6893 ** hook call with regards to the final result of the operation which
6894 ** triggers the hook.
6895 **
6896 ** The update hook implementation must not do anything that will modify
6897 ** the database connection that invoked the update hook. Any actions
6898 ** to modify the database connection must be deferred until after the
6899 ** completion of the [sqlite3_step()] call that triggered the update hook.
6900 ** Note that [sqlite3_prepare_v2()] and [sqlite3_step()] both modify their
6901 ** database connections for the meaning of "modify" in this paragraph.
6902 **
6903 ** ^The sqlite3_update_hook(D,C,P) function
6904 ** returns the P argument from the previous call
6905 ** on the same [database connection] D, or NULL for
6906 ** the first call on D.
6907 **
6908 ** See also the [sqlite3_commit_hook()], [sqlite3_rollback_hook()],
6909 ** and [sqlite3_preupdate_hook()] interfaces.
6910 */
6911 SQLITE_API void *sqlite3_update_hook(
6912 sqlite3*,
6913 void(*)(void *,int ,char const *,char const *,sqlite3_int64),
6914 void*
6915 );
6916
6917 /*
6918 ** CAPI3REF: Enable Or Disable Shared Pager Cache
6919 **
6920 ** ^(This routine enables or disables the sharing of the database cache
6921 ** and schema data structures between [database connection | connections]
6922 ** to the same database. Sharing is enabled if the argument is true
6923 ** and disabled if the argument is false.)^
6924 **
6925 ** This interface is omitted if SQLite is compiled with
6926 ** [-DSQLITE_OMIT_SHARED_CACHE]. The [-DSQLITE_OMIT_SHARED_CACHE]
6927 ** compile-time option is recommended because the
6928 ** [use of shared cache mode is discouraged].
6929 **
6930 ** ^Cache sharing is enabled and disabled for an entire process.
6931 ** This is a change as of SQLite [version 3.5.0] ([dateof:3.5.0]).
6932 ** In prior versions of SQLite,
6933 ** sharing was enabled or disabled for each thread separately.
6934 **
6935 ** ^(The cache sharing mode set by this interface effects all subsequent
6936 ** calls to [sqlite3_open()], [sqlite3_open_v2()], and [sqlite3_open16()].
6937 ** Existing database connections continue to use the sharing mode
6938 ** that was in effect at the time they were opened.)^
6939 **
6940 ** ^(This routine returns [SQLITE_OK] if shared cache was enabled or disabled
6941 ** successfully. An [error code] is returned otherwise.)^
6942 **
6943 ** ^Shared cache is disabled by default. It is recommended that it stay
6944 ** that way. In other words, do not use this routine. This interface
6945 ** continues to be provided for historical compatibility, but its use is
6946 ** discouraged. Any use of shared cache is discouraged. If shared cache
6947 ** must be used, it is recommended that shared cache only be enabled for
6948 ** individual database connections using the [sqlite3_open_v2()] interface
6949 ** with the [SQLITE_OPEN_SHAREDCACHE] flag.
6950 **
6951 ** Note: This method is disabled on MacOS X 10.7 and iOS version 5.0
6952 ** and will always return SQLITE_MISUSE. On those systems,
6953 ** shared cache mode should be enabled per-database connection via
6954 ** [sqlite3_open_v2()] with [SQLITE_OPEN_SHAREDCACHE].
6955 **
6956 ** This interface is threadsafe on processors where writing a
6957 ** 32-bit integer is atomic.
6958 **
6959 ** See Also: [SQLite Shared-Cache Mode]
6960 */
6961 SQLITE_API int sqlite3_enable_shared_cache(int);
6962
6963 /*
6964 ** CAPI3REF: Attempt To Free Heap Memory
6965 **
6966 ** ^The sqlite3_release_memory() interface attempts to free N bytes
6967 ** of heap memory by deallocating non-essential memory allocations
6968 ** held by the database library. Memory used to cache database
6969 ** pages to improve performance is an example of non-essential memory.
6970 ** ^sqlite3_release_memory() returns the number of bytes actually freed,
6971 ** which might be more or less than the amount requested.
6972 ** ^The sqlite3_release_memory() routine is a no-op returning zero
6973 ** if SQLite is not compiled with [SQLITE_ENABLE_MEMORY_MANAGEMENT].
6974 **
6975 ** See also: [sqlite3_db_release_memory()]
6976 */
6977 SQLITE_API int sqlite3_release_memory(int);
6978
6979 /*
6980 ** CAPI3REF: Free Memory Used By A Database Connection
6981 ** METHOD: sqlite3
6982 **
6983 ** ^The sqlite3_db_release_memory(D) interface attempts to free as much heap
6984 ** memory as possible from database connection D. Unlike the
6985 ** [sqlite3_release_memory()] interface, this interface is in effect even
6986 ** when the [SQLITE_ENABLE_MEMORY_MANAGEMENT] compile-time option is
6987 ** omitted.
6988 **
6989 ** See also: [sqlite3_release_memory()]
6990 */
6991 SQLITE_API int sqlite3_db_release_memory(sqlite3*);
6992
6993 /*
6994 ** CAPI3REF: Impose A Limit On Heap Size
6995 **
6996 ** These interfaces impose limits on the amount of heap memory that will be
6997 ** by all database connections within a single process.
6998 **
6999 ** ^The sqlite3_soft_heap_limit64() interface sets and/or queries the
7000 ** soft limit on the amount of heap memory that may be allocated by SQLite.
7001 ** ^SQLite strives to keep heap memory utilization below the soft heap
7002 ** limit by reducing the number of pages held in the page cache
7003 ** as heap memory usages approaches the limit.
7004 ** ^The soft heap limit is "soft" because even though SQLite strives to stay
7005 ** below the limit, it will exceed the limit rather than generate
7006 ** an [SQLITE_NOMEM] error. In other words, the soft heap limit
7007 ** is advisory only.
7008 **
7009 ** ^The sqlite3_hard_heap_limit64(N) interface sets a hard upper bound of
7010 ** N bytes on the amount of memory that will be allocated. ^The
7011 ** sqlite3_hard_heap_limit64(N) interface is similar to
7012 ** sqlite3_soft_heap_limit64(N) except that memory allocations will fail
7013 ** when the hard heap limit is reached.
7014 **
7015 ** ^The return value from both sqlite3_soft_heap_limit64() and
7016 ** sqlite3_hard_heap_limit64() is the size of
7017 ** the heap limit prior to the call, or negative in the case of an
7018 ** error. ^If the argument N is negative
7019 ** then no change is made to the heap limit. Hence, the current
7020 ** size of heap limits can be determined by invoking
7021 ** sqlite3_soft_heap_limit64(-1) or sqlite3_hard_heap_limit(-1).
7022 **
7023 ** ^Setting the heap limits to zero disables the heap limiter mechanism.
7024 **
7025 ** ^The soft heap limit may not be greater than the hard heap limit.
7026 ** ^If the hard heap limit is enabled and if sqlite3_soft_heap_limit(N)
7027 ** is invoked with a value of N that is greater than the hard heap limit,
7028 ** the soft heap limit is set to the value of the hard heap limit.
7029 ** ^The soft heap limit is automatically enabled whenever the hard heap
7030 ** limit is enabled. ^When sqlite3_hard_heap_limit64(N) is invoked and
7031 ** the soft heap limit is outside the range of 1..N, then the soft heap
7032 ** limit is set to N. ^Invoking sqlite3_soft_heap_limit64(0) when the
7033 ** hard heap limit is enabled makes the soft heap limit equal to the
7034 ** hard heap limit.
7035 **
7036 ** The memory allocation limits can also be adjusted using
7037 ** [PRAGMA soft_heap_limit] and [PRAGMA hard_heap_limit].
7038 **
7039 ** ^(The heap limits are not enforced in the current implementation
7040 ** if one or more of following conditions are true:
7041 **
7042 ** <ul>
7043 ** <li> The limit value is set to zero.
7044 ** <li> Memory accounting is disabled using a combination of the
7045 ** [sqlite3_config]([SQLITE_CONFIG_MEMSTATUS],...) start-time option and
7046 ** the [SQLITE_DEFAULT_MEMSTATUS] compile-time option.
7047 ** <li> An alternative page cache implementation is specified using
7048 ** [sqlite3_config]([SQLITE_CONFIG_PCACHE2],...).
7049 ** <li> The page cache allocates from its own memory pool supplied
7050 ** by [sqlite3_config]([SQLITE_CONFIG_PAGECACHE],...) rather than
7051 ** from the heap.
7052 ** </ul>)^
7053 **
7054 ** The circumstances under which SQLite will enforce the heap limits may
7055 ** changes in future releases of SQLite.
7056 */
7057 SQLITE_API sqlite3_int64 sqlite3_soft_heap_limit64(sqlite3_int64 N);
7058 SQLITE_API sqlite3_int64 sqlite3_hard_heap_limit64(sqlite3_int64 N);
7059
7060 /*
7061 ** CAPI3REF: Deprecated Soft Heap Limit Interface
7062 ** DEPRECATED
7063 **
7064 ** This is a deprecated version of the [sqlite3_soft_heap_limit64()]
7065 ** interface. This routine is provided for historical compatibility
7066 ** only. All new applications should use the
7067 ** [sqlite3_soft_heap_limit64()] interface rather than this one.
7068 */
7069 SQLITE_API SQLITE_DEPRECATED void sqlite3_soft_heap_limit(int N);
7070
7071
7072 /*
7073 ** CAPI3REF: Extract Metadata About A Column Of A Table
7074 ** METHOD: sqlite3
7075 **
7076 ** ^(The sqlite3_table_column_metadata(X,D,T,C,....) routine returns
7077 ** information about column C of table T in database D
7078 ** on [database connection] X.)^ ^The sqlite3_table_column_metadata()
7079 ** interface returns SQLITE_OK and fills in the non-NULL pointers in
7080 ** the final five arguments with appropriate values if the specified
7081 ** column exists. ^The sqlite3_table_column_metadata() interface returns
7082 ** SQLITE_ERROR if the specified column does not exist.
7083 ** ^If the column-name parameter to sqlite3_table_column_metadata() is a
7084 ** NULL pointer, then this routine simply checks for the existence of the
7085 ** table and returns SQLITE_OK if the table exists and SQLITE_ERROR if it
7086 ** does not. If the table name parameter T in a call to
7087 ** sqlite3_table_column_metadata(X,D,T,C,...) is NULL then the result is
7088 ** undefined behavior.
7089 **
7090 ** ^The column is identified by the second, third and fourth parameters to
7091 ** this function. ^(The second parameter is either the name of the database
7092 ** (i.e. "main", "temp", or an attached database) containing the specified
7093 ** table or NULL.)^ ^If it is NULL, then all attached databases are searched
7094 ** for the table using the same algorithm used by the database engine to
7095 ** resolve unqualified table references.
7096 **
7097 ** ^The third and fourth parameters to this function are the table and column
7098 ** name of the desired column, respectively.
7099 **
7100 ** ^Metadata is returned by writing to the memory locations passed as the 5th
7101 ** and subsequent parameters to this function. ^Any of these arguments may be
7102 ** NULL, in which case the corresponding element of metadata is omitted.
7103 **
7104 ** ^(<blockquote>
7105 ** <table border="1">
7106 ** <tr><th> Parameter <th> Output<br>Type <th> Description
7107 **
7108 ** <tr><td> 5th <td> const char* <td> Data type
7109 ** <tr><td> 6th <td> const char* <td> Name of default collation sequence
7110 ** <tr><td> 7th <td> int <td> True if column has a NOT NULL constraint
7111 ** <tr><td> 8th <td> int <td> True if column is part of the PRIMARY KEY
7112 ** <tr><td> 9th <td> int <td> True if column is [AUTOINCREMENT]
7113 ** </table>
7114 ** </blockquote>)^
7115 **
7116 ** ^The memory pointed to by the character pointers returned for the
7117 ** declaration type and collation sequence is valid until the next
7118 ** call to any SQLite API function.
7119 **
7120 ** ^If the specified table is actually a view, an [error code] is returned.
7121 **
7122 ** ^If the specified column is "rowid", "oid" or "_rowid_" and the table
7123 ** is not a [WITHOUT ROWID] table and an
7124 ** [INTEGER PRIMARY KEY] column has been explicitly declared, then the output
7125 ** parameters are set for the explicitly declared column. ^(If there is no
7126 ** [INTEGER PRIMARY KEY] column, then the outputs
7127 ** for the [rowid] are set as follows:
7128 **
7129 ** <pre>
7130 ** data type: "INTEGER"
7131 ** collation sequence: "BINARY"
7132 ** not null: 0
7133 ** primary key: 1
7134 ** auto increment: 0
7135 ** </pre>)^
7136 **
7137 ** ^This function causes all database schemas to be read from disk and
7138 ** parsed, if that has not already been done, and returns an error if
7139 ** any errors are encountered while loading the schema.
7140 */
7141 SQLITE_API int sqlite3_table_column_metadata(
7142 sqlite3 *db, /* Connection handle */
7143 const char *zDbName, /* Database name or NULL */
7144 const char *zTableName, /* Table name */
7145 const char *zColumnName, /* Column name */
7146 char const **pzDataType, /* OUTPUT: Declared data type */
7147 char const **pzCollSeq, /* OUTPUT: Collation sequence name */
7148 int *pNotNull, /* OUTPUT: True if NOT NULL constraint exists */
7149 int *pPrimaryKey, /* OUTPUT: True if column part of PK */
7150 int *pAutoinc /* OUTPUT: True if column is auto-increment */
7151 );
7152
7153 /*
7154 ** CAPI3REF: Load An Extension
7155 ** METHOD: sqlite3
7156 **
7157 ** ^This interface loads an SQLite extension library from the named file.
7158 **
7159 ** ^The sqlite3_load_extension() interface attempts to load an
7160 ** [SQLite extension] library contained in the file zFile. If
7161 ** the file cannot be loaded directly, attempts are made to load
7162 ** with various operating-system specific extensions added.
7163 ** So for example, if "samplelib" cannot be loaded, then names like
7164 ** "samplelib.so" or "samplelib.dylib" or "samplelib.dll" might
7165 ** be tried also.
7166 **
7167 ** ^The entry point is zProc.
7168 ** ^(zProc may be 0, in which case SQLite will try to come up with an
7169 ** entry point name on its own. It first tries "sqlite3_extension_init".
7170 ** If that does not work, it constructs a name "sqlite3_X_init" where the
7171 ** X is consists of the lower-case equivalent of all ASCII alphabetic
7172 ** characters in the filename from the last "/" to the first following
7173 ** "." and omitting any initial "lib".)^
7174 ** ^The sqlite3_load_extension() interface returns
7175 ** [SQLITE_OK] on success and [SQLITE_ERROR] if something goes wrong.
7176 ** ^If an error occurs and pzErrMsg is not 0, then the
7177 ** [sqlite3_load_extension()] interface shall attempt to
7178 ** fill *pzErrMsg with error message text stored in memory
7179 ** obtained from [sqlite3_malloc()]. The calling function
7180 ** should free this memory by calling [sqlite3_free()].
7181 **
7182 ** ^Extension loading must be enabled using
7183 ** [sqlite3_enable_load_extension()] or
7184 ** [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],1,NULL)
7185 ** prior to calling this API,
7186 ** otherwise an error will be returned.
7187 **
7188 ** <b>Security warning:</b> It is recommended that the
7189 ** [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method be used to enable only this
7190 ** interface. The use of the [sqlite3_enable_load_extension()] interface
7191 ** should be avoided. This will keep the SQL function [load_extension()]
7192 ** disabled and prevent SQL injections from giving attackers
7193 ** access to extension loading capabilities.
7194 **
7195 ** See also the [load_extension() SQL function].
7196 */
7197 SQLITE_API int sqlite3_load_extension(
7198 sqlite3 *db, /* Load the extension into this database connection */
7199 const char *zFile, /* Name of the shared library containing extension */
7200 const char *zProc, /* Entry point. Derived from zFile if 0 */
7201 char **pzErrMsg /* Put error message here if not 0 */
7202 );
7203
7204 /*
7205 ** CAPI3REF: Enable Or Disable Extension Loading
7206 ** METHOD: sqlite3
7207 **
7208 ** ^So as not to open security holes in older applications that are
7209 ** unprepared to deal with [extension loading], and as a means of disabling
7210 ** [extension loading] while evaluating user-entered SQL, the following API
7211 ** is provided to turn the [sqlite3_load_extension()] mechanism on and off.
7212 **
7213 ** ^Extension loading is off by default.
7214 ** ^Call the sqlite3_enable_load_extension() routine with onoff==1
7215 ** to turn extension loading on and call it with onoff==0 to turn
7216 ** it back off again.
7217 **
7218 ** ^This interface enables or disables both the C-API
7219 ** [sqlite3_load_extension()] and the SQL function [load_extension()].
7220 ** ^(Use [sqlite3_db_config](db,[SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION],..)
7221 ** to enable or disable only the C-API.)^
7222 **
7223 ** <b>Security warning:</b> It is recommended that extension loading
7224 ** be enabled using the [SQLITE_DBCONFIG_ENABLE_LOAD_EXTENSION] method
7225 ** rather than this interface, so the [load_extension()] SQL function
7226 ** remains disabled. This will prevent SQL injections from giving attackers
7227 ** access to extension loading capabilities.
7228 */
7229 SQLITE_API int sqlite3_enable_load_extension(sqlite3 *db, int onoff);
7230
7231 /*
7232 ** CAPI3REF: Automatically Load Statically Linked Extensions
7233 **
7234 ** ^This interface causes the xEntryPoint() function to be invoked for
7235 ** each new [database connection] that is created. The idea here is that
7236 ** xEntryPoint() is the entry point for a statically linked [SQLite extension]
7237 ** that is to be automatically loaded into all new database connections.
7238 **
7239 ** ^(Even though the function prototype shows that xEntryPoint() takes
7240 ** no arguments and returns void, SQLite invokes xEntryPoint() with three
7241 ** arguments and expects an integer result as if the signature of the
7242 ** entry point where as follows:
7243 **
7244 ** <blockquote><pre>
7245 ** &nbsp; int xEntryPoint(
7246 ** &nbsp; sqlite3 *db,
7247 ** &nbsp; const char **pzErrMsg,
7248 ** &nbsp; const struct sqlite3_api_routines *pThunk
7249 ** &nbsp; );
7250 ** </pre></blockquote>)^
7251 **
7252 ** If the xEntryPoint routine encounters an error, it should make *pzErrMsg
7253 ** point to an appropriate error message (obtained from [sqlite3_mprintf()])
7254 ** and return an appropriate [error code]. ^SQLite ensures that *pzErrMsg
7255 ** is NULL before calling the xEntryPoint(). ^SQLite will invoke
7256 ** [sqlite3_free()] on *pzErrMsg after xEntryPoint() returns. ^If any
7257 ** xEntryPoint() returns an error, the [sqlite3_open()], [sqlite3_open16()],
7258 ** or [sqlite3_open_v2()] call that provoked the xEntryPoint() will fail.
7259 **
7260 ** ^Calling sqlite3_auto_extension(X) with an entry point X that is already
7261 ** on the list of automatic extensions is a harmless no-op. ^No entry point
7262 ** will be called more than once for each database connection that is opened.
7263 **
7264 ** See also: [sqlite3_reset_auto_extension()]
7265 ** and [sqlite3_cancel_auto_extension()]
7266 */
7267 SQLITE_API int sqlite3_auto_extension(void(*xEntryPoint)(void));
7268
7269 /*
7270 ** CAPI3REF: Cancel Automatic Extension Loading
7271 **
7272 ** ^The [sqlite3_cancel_auto_extension(X)] interface unregisters the
7273 ** initialization routine X that was registered using a prior call to
7274 ** [sqlite3_auto_extension(X)]. ^The [sqlite3_cancel_auto_extension(X)]
7275 ** routine returns 1 if initialization routine X was successfully
7276 ** unregistered and it returns 0 if X was not on the list of initialization
7277 ** routines.
7278 */
7279 SQLITE_API int sqlite3_cancel_auto_extension(void(*xEntryPoint)(void));
7280
7281 /*
7282 ** CAPI3REF: Reset Automatic Extension Loading
7283 **
7284 ** ^This interface disables all automatic extensions previously
7285 ** registered using [sqlite3_auto_extension()].
7286 */
7287 SQLITE_API void sqlite3_reset_auto_extension(void);
7288
7289 /*
7290 ** Structures used by the virtual table interface
7291 */
7292 typedef struct sqlite3_vtab sqlite3_vtab;
7293 typedef struct sqlite3_index_info sqlite3_index_info;
7294 typedef struct sqlite3_vtab_cursor sqlite3_vtab_cursor;
7295 typedef struct sqlite3_module sqlite3_module;
7296
7297 /*
7298 ** CAPI3REF: Virtual Table Object
7299 ** KEYWORDS: sqlite3_module {virtual table module}
7300 **
7301 ** This structure, sometimes called a "virtual table module",
7302 ** defines the implementation of a [virtual table].
7303 ** This structure consists mostly of methods for the module.
7304 **
7305 ** ^A virtual table module is created by filling in a persistent
7306 ** instance of this structure and passing a pointer to that instance
7307 ** to [sqlite3_create_module()] or [sqlite3_create_module_v2()].
7308 ** ^The registration remains valid until it is replaced by a different
7309 ** module or until the [database connection] closes. The content
7310 ** of this structure must not change while it is registered with
7311 ** any database connection.
7312 */
7313 struct sqlite3_module {
7314 int iVersion;
7315 int (*xCreate)(sqlite3*, void *pAux,
7316 int argc, const char *const*argv,
7317 sqlite3_vtab **ppVTab, char**);
7318 int (*xConnect)(sqlite3*, void *pAux,
7319 int argc, const char *const*argv,
7320 sqlite3_vtab **ppVTab, char**);
7321 int (*xBestIndex)(sqlite3_vtab *pVTab, sqlite3_index_info*);
7322 int (*xDisconnect)(sqlite3_vtab *pVTab);
7323 int (*xDestroy)(sqlite3_vtab *pVTab);
7324 int (*xOpen)(sqlite3_vtab *pVTab, sqlite3_vtab_cursor **ppCursor);
7325 int (*xClose)(sqlite3_vtab_cursor*);
7326 int (*xFilter)(sqlite3_vtab_cursor*, int idxNum, const char *idxStr,
7327 int argc, sqlite3_value **argv);
7328 int (*xNext)(sqlite3_vtab_cursor*);
7329 int (*xEof)(sqlite3_vtab_cursor*);
7330 int (*xColumn)(sqlite3_vtab_cursor*, sqlite3_context*, int);
7331 int (*xRowid)(sqlite3_vtab_cursor*, sqlite3_int64 *pRowid);
7332 int (*xUpdate)(sqlite3_vtab *, int, sqlite3_value **, sqlite3_int64 *);
7333 int (*xBegin)(sqlite3_vtab *pVTab);
7334 int (*xSync)(sqlite3_vtab *pVTab);
7335 int (*xCommit)(sqlite3_vtab *pVTab);
7336 int (*xRollback)(sqlite3_vtab *pVTab);
7337 int (*xFindFunction)(sqlite3_vtab *pVtab, int nArg, const char *zName,
7338 void (**pxFunc)(sqlite3_context*,int,sqlite3_value**),
7339 void **ppArg);
7340 int (*xRename)(sqlite3_vtab *pVtab, const char *zNew);
7341 /* The methods above are in version 1 of the sqlite_module object. Those
7342 ** below are for version 2 and greater. */
7343 int (*xSavepoint)(sqlite3_vtab *pVTab, int);
7344 int (*xRelease)(sqlite3_vtab *pVTab, int);
7345 int (*xRollbackTo)(sqlite3_vtab *pVTab, int);
7346 /* The methods above are in versions 1 and 2 of the sqlite_module object.
7347 ** Those below are for version 3 and greater. */
7348 int (*xShadowName)(const char*);
7349 /* The methods above are in versions 1 through 3 of the sqlite_module object.
7350 ** Those below are for version 4 and greater. */
7351 int (*xIntegrity)(sqlite3_vtab *pVTab, const char *zSchema,
7352 const char *zTabName, int mFlags, char **pzErr);
7353 };
7354
7355 /*
7356 ** CAPI3REF: Virtual Table Indexing Information
7357 ** KEYWORDS: sqlite3_index_info
7358 **
7359 ** The sqlite3_index_info structure and its substructures is used as part
7360 ** of the [virtual table] interface to
7361 ** pass information into and receive the reply from the [xBestIndex]
7362 ** method of a [virtual table module]. The fields under **Inputs** are the
7363 ** inputs to xBestIndex and are read-only. xBestIndex inserts its
7364 ** results into the **Outputs** fields.
7365 **
7366 ** ^(The aConstraint[] array records WHERE clause constraints of the form:
7367 **
7368 ** <blockquote>column OP expr</blockquote>
7369 **
7370 ** where OP is =, &lt;, &lt;=, &gt;, or &gt;=.)^ ^(The particular operator is
7371 ** stored in aConstraint[].op using one of the
7372 ** [SQLITE_INDEX_CONSTRAINT_EQ | SQLITE_INDEX_CONSTRAINT_ values].)^
7373 ** ^(The index of the column is stored in
7374 ** aConstraint[].iColumn.)^ ^(aConstraint[].usable is TRUE if the
7375 ** expr on the right-hand side can be evaluated (and thus the constraint
7376 ** is usable) and false if it cannot.)^
7377 **
7378 ** ^The optimizer automatically inverts terms of the form "expr OP column"
7379 ** and makes other simplifications to the WHERE clause in an attempt to
7380 ** get as many WHERE clause terms into the form shown above as possible.
7381 ** ^The aConstraint[] array only reports WHERE clause terms that are
7382 ** relevant to the particular virtual table being queried.
7383 **
7384 ** ^Information about the ORDER BY clause is stored in aOrderBy[].
7385 ** ^Each term of aOrderBy records a column of the ORDER BY clause.
7386 **
7387 ** The colUsed field indicates which columns of the virtual table may be
7388 ** required by the current scan. Virtual table columns are numbered from
7389 ** zero in the order in which they appear within the CREATE TABLE statement
7390 ** passed to sqlite3_declare_vtab(). For the first 63 columns (columns 0-62),
7391 ** the corresponding bit is set within the colUsed mask if the column may be
7392 ** required by SQLite. If the table has at least 64 columns and any column
7393 ** to the right of the first 63 is required, then bit 63 of colUsed is also
7394 ** set. In other words, column iCol may be required if the expression
7395 ** (colUsed & ((sqlite3_uint64)1 << (iCol>=63 ? 63 : iCol))) evaluates to
7396 ** non-zero.
7397 **
7398 ** The [xBestIndex] method must fill aConstraintUsage[] with information
7399 ** about what parameters to pass to xFilter. ^If argvIndex>0 then
7400 ** the right-hand side of the corresponding aConstraint[] is evaluated
7401 ** and becomes the argvIndex-th entry in argv. ^(If aConstraintUsage[].omit
7402 ** is true, then the constraint is assumed to be fully handled by the
7403 ** virtual table and might not be checked again by the byte code.)^ ^(The
7404 ** aConstraintUsage[].omit flag is an optimization hint. When the omit flag
7405 ** is left in its default setting of false, the constraint will always be
7406 ** checked separately in byte code. If the omit flag is change to true, then
7407 ** the constraint may or may not be checked in byte code. In other words,
7408 ** when the omit flag is true there is no guarantee that the constraint will
7409 ** not be checked again using byte code.)^
7410 **
7411 ** ^The idxNum and idxStr values are recorded and passed into the
7412 ** [xFilter] method.
7413 ** ^[sqlite3_free()] is used to free idxStr if and only if
7414 ** needToFreeIdxStr is true.
7415 **
7416 ** ^The orderByConsumed means that output from [xFilter]/[xNext] will occur in
7417 ** the correct order to satisfy the ORDER BY clause so that no separate
7418 ** sorting step is required.
7419 **
7420 ** ^The estimatedCost value is an estimate of the cost of a particular
7421 ** strategy. A cost of N indicates that the cost of the strategy is similar
7422 ** to a linear scan of an SQLite table with N rows. A cost of log(N)
7423 ** indicates that the expense of the operation is similar to that of a
7424 ** binary search on a unique indexed field of an SQLite table with N rows.
7425 **
7426 ** ^The estimatedRows value is an estimate of the number of rows that
7427 ** will be returned by the strategy.
7428 **
7429 ** The xBestIndex method may optionally populate the idxFlags field with a
7430 ** mask of SQLITE_INDEX_SCAN_* flags. Currently there is only one such flag -
7431 ** SQLITE_INDEX_SCAN_UNIQUE. If the xBestIndex method sets this flag, SQLite
7432 ** assumes that the strategy may visit at most one row.
7433 **
7434 ** Additionally, if xBestIndex sets the SQLITE_INDEX_SCAN_UNIQUE flag, then
7435 ** SQLite also assumes that if a call to the xUpdate() method is made as
7436 ** part of the same statement to delete or update a virtual table row and the
7437 ** implementation returns SQLITE_CONSTRAINT, then there is no need to rollback
7438 ** any database changes. In other words, if the xUpdate() returns
7439 ** SQLITE_CONSTRAINT, the database contents must be exactly as they were
7440 ** before xUpdate was called. By contrast, if SQLITE_INDEX_SCAN_UNIQUE is not
7441 ** set and xUpdate returns SQLITE_CONSTRAINT, any database changes made by
7442 ** the xUpdate method are automatically rolled back by SQLite.
7443 **
7444 ** IMPORTANT: The estimatedRows field was added to the sqlite3_index_info
7445 ** structure for SQLite [version 3.8.2] ([dateof:3.8.2]).
7446 ** If a virtual table extension is
7447 ** used with an SQLite version earlier than 3.8.2, the results of attempting
7448 ** to read or write the estimatedRows field are undefined (but are likely
7449 ** to include crashing the application). The estimatedRows field should
7450 ** therefore only be used if [sqlite3_libversion_number()] returns a
7451 ** value greater than or equal to 3008002. Similarly, the idxFlags field
7452 ** was added for [version 3.9.0] ([dateof:3.9.0]).
7453 ** It may therefore only be used if
7454 ** sqlite3_libversion_number() returns a value greater than or equal to
7455 ** 3009000.
7456 */
7457 struct sqlite3_index_info {
7458 /* Inputs */
7459 int nConstraint; /* Number of entries in aConstraint */
7460 struct sqlite3_index_constraint {
7461 int iColumn; /* Column constrained. -1 for ROWID */
7462 unsigned char op; /* Constraint operator */
7463 unsigned char usable; /* True if this constraint is usable */
7464 int iTermOffset; /* Used internally - xBestIndex should ignore */
7465 } *aConstraint; /* Table of WHERE clause constraints */
7466 int nOrderBy; /* Number of terms in the ORDER BY clause */
7467 struct sqlite3_index_orderby {
7468 int iColumn; /* Column number */
7469 unsigned char desc; /* True for DESC. False for ASC. */
7470 } *aOrderBy; /* The ORDER BY clause */
7471 /* Outputs */
7472 struct sqlite3_index_constraint_usage {
7473 int argvIndex; /* if >0, constraint is part of argv to xFilter */
7474 unsigned char omit; /* Do not code a test for this constraint */
7475 } *aConstraintUsage;
7476 int idxNum; /* Number used to identify the index */
7477 char *idxStr; /* String, possibly obtained from sqlite3_malloc */
7478 int needToFreeIdxStr; /* Free idxStr using sqlite3_free() if true */
7479 int orderByConsumed; /* True if output is already ordered */
7480 double estimatedCost; /* Estimated cost of using this index */
7481 /* Fields below are only available in SQLite 3.8.2 and later */
7482 sqlite3_int64 estimatedRows; /* Estimated number of rows returned */
7483 /* Fields below are only available in SQLite 3.9.0 and later */
7484 int idxFlags; /* Mask of SQLITE_INDEX_SCAN_* flags */
7485 /* Fields below are only available in SQLite 3.10.0 and later */
7486 sqlite3_uint64 colUsed; /* Input: Mask of columns used by statement */
7487 };
7488
7489 /*
7490 ** CAPI3REF: Virtual Table Scan Flags
7491 **
7492 ** Virtual table implementations are allowed to set the
7493 ** [sqlite3_index_info].idxFlags field to some combination of
7494 ** these bits.
7495 */
7496 #define SQLITE_INDEX_SCAN_UNIQUE 1 /* Scan visits at most 1 row */
7497
7498 /*
7499 ** CAPI3REF: Virtual Table Constraint Operator Codes
7500 **
7501 ** These macros define the allowed values for the
7502 ** [sqlite3_index_info].aConstraint[].op field. Each value represents
7503 ** an operator that is part of a constraint term in the WHERE clause of
7504 ** a query that uses a [virtual table].
7505 **
7506 ** ^The left-hand operand of the operator is given by the corresponding
7507 ** aConstraint[].iColumn field. ^An iColumn of -1 indicates the left-hand
7508 ** operand is the rowid.
7509 ** The SQLITE_INDEX_CONSTRAINT_LIMIT and SQLITE_INDEX_CONSTRAINT_OFFSET
7510 ** operators have no left-hand operand, and so for those operators the
7511 ** corresponding aConstraint[].iColumn is meaningless and should not be
7512 ** used.
7513 **
7514 ** All operator values from SQLITE_INDEX_CONSTRAINT_FUNCTION through
7515 ** value 255 are reserved to represent functions that are overloaded
7516 ** by the [xFindFunction|xFindFunction method] of the virtual table
7517 ** implementation.
7518 **
7519 ** The right-hand operands for each constraint might be accessible using
7520 ** the [sqlite3_vtab_rhs_value()] interface. Usually the right-hand
7521 ** operand is only available if it appears as a single constant literal
7522 ** in the input SQL. If the right-hand operand is another column or an
7523 ** expression (even a constant expression) or a parameter, then the
7524 ** sqlite3_vtab_rhs_value() probably will not be able to extract it.
7525 ** ^The SQLITE_INDEX_CONSTRAINT_ISNULL and
7526 ** SQLITE_INDEX_CONSTRAINT_ISNOTNULL operators have no right-hand operand
7527 ** and hence calls to sqlite3_vtab_rhs_value() for those operators will
7528 ** always return SQLITE_NOTFOUND.
7529 **
7530 ** The collating sequence to be used for comparison can be found using
7531 ** the [sqlite3_vtab_collation()] interface. For most real-world virtual
7532 ** tables, the collating sequence of constraints does not matter (for example
7533 ** because the constraints are numeric) and so the sqlite3_vtab_collation()
7534 ** interface is not commonly needed.
7535 */
7536 #define SQLITE_INDEX_CONSTRAINT_EQ 2
7537 #define SQLITE_INDEX_CONSTRAINT_GT 4
7538 #define SQLITE_INDEX_CONSTRAINT_LE 8
7539 #define SQLITE_INDEX_CONSTRAINT_LT 16
7540 #define SQLITE_INDEX_CONSTRAINT_GE 32
7541 #define SQLITE_INDEX_CONSTRAINT_MATCH 64
7542 #define SQLITE_INDEX_CONSTRAINT_LIKE 65
7543 #define SQLITE_INDEX_CONSTRAINT_GLOB 66
7544 #define SQLITE_INDEX_CONSTRAINT_REGEXP 67
7545 #define SQLITE_INDEX_CONSTRAINT_NE 68
7546 #define SQLITE_INDEX_CONSTRAINT_ISNOT 69
7547 #define SQLITE_INDEX_CONSTRAINT_ISNOTNULL 70
7548 #define SQLITE_INDEX_CONSTRAINT_ISNULL 71
7549 #define SQLITE_INDEX_CONSTRAINT_IS 72
7550 #define SQLITE_INDEX_CONSTRAINT_LIMIT 73
7551 #define SQLITE_INDEX_CONSTRAINT_OFFSET 74
7552 #define SQLITE_INDEX_CONSTRAINT_FUNCTION 150
7553
7554 /*
7555 ** CAPI3REF: Register A Virtual Table Implementation
7556 ** METHOD: sqlite3
7557 **
7558 ** ^These routines are used to register a new [virtual table module] name.
7559 ** ^Module names must be registered before
7560 ** creating a new [virtual table] using the module and before using a
7561 ** preexisting [virtual table] for the module.
7562 **
7563 ** ^The module name is registered on the [database connection] specified
7564 ** by the first parameter. ^The name of the module is given by the
7565 ** second parameter. ^The third parameter is a pointer to
7566 ** the implementation of the [virtual table module]. ^The fourth
7567 ** parameter is an arbitrary client data pointer that is passed through
7568 ** into the [xCreate] and [xConnect] methods of the virtual table module
7569 ** when a new virtual table is be being created or reinitialized.
7570 **
7571 ** ^The sqlite3_create_module_v2() interface has a fifth parameter which
7572 ** is a pointer to a destructor for the pClientData. ^SQLite will
7573 ** invoke the destructor function (if it is not NULL) when SQLite
7574 ** no longer needs the pClientData pointer. ^The destructor will also
7575 ** be invoked if the call to sqlite3_create_module_v2() fails.
7576 ** ^The sqlite3_create_module()
7577 ** interface is equivalent to sqlite3_create_module_v2() with a NULL
7578 ** destructor.
7579 **
7580 ** ^If the third parameter (the pointer to the sqlite3_module object) is
7581 ** NULL then no new module is created and any existing modules with the
7582 ** same name are dropped.
7583 **
7584 ** See also: [sqlite3_drop_modules()]
7585 */
7586 SQLITE_API int sqlite3_create_module(
7587 sqlite3 *db, /* SQLite connection to register module with */
7588 const char *zName, /* Name of the module */
7589 const sqlite3_module *p, /* Methods for the module */
7590 void *pClientData /* Client data for xCreate/xConnect */
7591 );
7592 SQLITE_API int sqlite3_create_module_v2(
7593 sqlite3 *db, /* SQLite connection to register module with */
7594 const char *zName, /* Name of the module */
7595 const sqlite3_module *p, /* Methods for the module */
7596 void *pClientData, /* Client data for xCreate/xConnect */
7597 void(*xDestroy)(void*) /* Module destructor function */
7598 );
7599
7600 /*
7601 ** CAPI3REF: Remove Unnecessary Virtual Table Implementations
7602 ** METHOD: sqlite3
7603 **
7604 ** ^The sqlite3_drop_modules(D,L) interface removes all virtual
7605 ** table modules from database connection D except those named on list L.
7606 ** The L parameter must be either NULL or a pointer to an array of pointers
7607 ** to strings where the array is terminated by a single NULL pointer.
7608 ** ^If the L parameter is NULL, then all virtual table modules are removed.
7609 **
7610 ** See also: [sqlite3_create_module()]
7611 */
7612 SQLITE_API int sqlite3_drop_modules(
7613 sqlite3 *db, /* Remove modules from this connection */
7614 const char **azKeep /* Except, do not remove the ones named here */
7615 );
7616
7617 /*
7618 ** CAPI3REF: Virtual Table Instance Object
7619 ** KEYWORDS: sqlite3_vtab
7620 **
7621 ** Every [virtual table module] implementation uses a subclass
7622 ** of this object to describe a particular instance
7623 ** of the [virtual table]. Each subclass will
7624 ** be tailored to the specific needs of the module implementation.
7625 ** The purpose of this superclass is to define certain fields that are
7626 ** common to all module implementations.
7627 **
7628 ** ^Virtual tables methods can set an error message by assigning a
7629 ** string obtained from [sqlite3_mprintf()] to zErrMsg. The method should
7630 ** take care that any prior string is freed by a call to [sqlite3_free()]
7631 ** prior to assigning a new string to zErrMsg. ^After the error message
7632 ** is delivered up to the client application, the string will be automatically
7633 ** freed by sqlite3_free() and the zErrMsg field will be zeroed.
7634 */
7635 struct sqlite3_vtab {
7636 const sqlite3_module *pModule; /* The module for this virtual table */
7637 int nRef; /* Number of open cursors */
7638 char *zErrMsg; /* Error message from sqlite3_mprintf() */
7639 /* Virtual table implementations will typically add additional fields */
7640 };
7641
7642 /*
7643 ** CAPI3REF: Virtual Table Cursor Object
7644 ** KEYWORDS: sqlite3_vtab_cursor {virtual table cursor}
7645 **
7646 ** Every [virtual table module] implementation uses a subclass of the
7647 ** following structure to describe cursors that point into the
7648 ** [virtual table] and are used
7649 ** to loop through the virtual table. Cursors are created using the
7650 ** [sqlite3_module.xOpen | xOpen] method of the module and are destroyed
7651 ** by the [sqlite3_module.xClose | xClose] method. Cursors are used
7652 ** by the [xFilter], [xNext], [xEof], [xColumn], and [xRowid] methods
7653 ** of the module. Each module implementation will define
7654 ** the content of a cursor structure to suit its own needs.
7655 **
7656 ** This superclass exists in order to define fields of the cursor that
7657 ** are common to all implementations.
7658 */
7659 struct sqlite3_vtab_cursor {
7660 sqlite3_vtab *pVtab; /* Virtual table of this cursor */
7661 /* Virtual table implementations will typically add additional fields */
7662 };
7663
7664 /*
7665 ** CAPI3REF: Declare The Schema Of A Virtual Table
7666 **
7667 ** ^The [xCreate] and [xConnect] methods of a
7668 ** [virtual table module] call this interface
7669 ** to declare the format (the names and datatypes of the columns) of
7670 ** the virtual tables they implement.
7671 */
7672 SQLITE_API int sqlite3_declare_vtab(sqlite3*, const char *zSQL);
7673
7674 /*
7675 ** CAPI3REF: Overload A Function For A Virtual Table
7676 ** METHOD: sqlite3
7677 **
7678 ** ^(Virtual tables can provide alternative implementations of functions
7679 ** using the [xFindFunction] method of the [virtual table module].
7680 ** But global versions of those functions
7681 ** must exist in order to be overloaded.)^
7682 **
7683 ** ^(This API makes sure a global version of a function with a particular
7684 ** name and number of parameters exists. If no such function exists
7685 ** before this API is called, a new function is created.)^ ^The implementation
7686 ** of the new function always causes an exception to be thrown. So
7687 ** the new function is not good for anything by itself. Its only
7688 ** purpose is to be a placeholder function that can be overloaded
7689 ** by a [virtual table].
7690 */
7691 SQLITE_API int sqlite3_overload_function(sqlite3*, const char *zFuncName, int nArg);
7692
7693 /*
7694 ** CAPI3REF: A Handle To An Open BLOB
7695 ** KEYWORDS: {BLOB handle} {BLOB handles}
7696 **
7697 ** An instance of this object represents an open BLOB on which
7698 ** [sqlite3_blob_open | incremental BLOB I/O] can be performed.
7699 ** ^Objects of this type are created by [sqlite3_blob_open()]
7700 ** and destroyed by [sqlite3_blob_close()].
7701 ** ^The [sqlite3_blob_read()] and [sqlite3_blob_write()] interfaces
7702 ** can be used to read or write small subsections of the BLOB.
7703 ** ^The [sqlite3_blob_bytes()] interface returns the size of the BLOB in bytes.
7704 */
7705 typedef struct sqlite3_blob sqlite3_blob;
7706
7707 /*
7708 ** CAPI3REF: Open A BLOB For Incremental I/O
7709 ** METHOD: sqlite3
7710 ** CONSTRUCTOR: sqlite3_blob
7711 **
7712 ** ^(This interfaces opens a [BLOB handle | handle] to the BLOB located
7713 ** in row iRow, column zColumn, table zTable in database zDb;
7714 ** in other words, the same BLOB that would be selected by:
7715 **
7716 ** <pre>
7717 ** SELECT zColumn FROM zDb.zTable WHERE [rowid] = iRow;
7718 ** </pre>)^
7719 **
7720 ** ^(Parameter zDb is not the filename that contains the database, but
7721 ** rather the symbolic name of the database. For attached databases, this is
7722 ** the name that appears after the AS keyword in the [ATTACH] statement.
7723 ** For the main database file, the database name is "main". For TEMP
7724 ** tables, the database name is "temp".)^
7725 **
7726 ** ^If the flags parameter is non-zero, then the BLOB is opened for read
7727 ** and write access. ^If the flags parameter is zero, the BLOB is opened for
7728 ** read-only access.
7729 **
7730 ** ^(On success, [SQLITE_OK] is returned and the new [BLOB handle] is stored
7731 ** in *ppBlob. Otherwise an [error code] is returned and, unless the error
7732 ** code is SQLITE_MISUSE, *ppBlob is set to NULL.)^ ^This means that, provided
7733 ** the API is not misused, it is always safe to call [sqlite3_blob_close()]
7734 ** on *ppBlob after this function it returns.
7735 **
7736 ** This function fails with SQLITE_ERROR if any of the following are true:
7737 ** <ul>
7738 ** <li> ^(Database zDb does not exist)^,
7739 ** <li> ^(Table zTable does not exist within database zDb)^,
7740 ** <li> ^(Table zTable is a WITHOUT ROWID table)^,
7741 ** <li> ^(Column zColumn does not exist)^,
7742 ** <li> ^(Row iRow is not present in the table)^,
7743 ** <li> ^(The specified column of row iRow contains a value that is not
7744 ** a TEXT or BLOB value)^,
7745 ** <li> ^(Column zColumn is part of an index, PRIMARY KEY or UNIQUE
7746 ** constraint and the blob is being opened for read/write access)^,
7747 ** <li> ^([foreign key constraints | Foreign key constraints] are enabled,
7748 ** column zColumn is part of a [child key] definition and the blob is
7749 ** being opened for read/write access)^.
7750 ** </ul>
7751 **
7752 ** ^Unless it returns SQLITE_MISUSE, this function sets the
7753 ** [database connection] error code and message accessible via
7754 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
7755 **
7756 ** A BLOB referenced by sqlite3_blob_open() may be read using the
7757 ** [sqlite3_blob_read()] interface and modified by using
7758 ** [sqlite3_blob_write()]. The [BLOB handle] can be moved to a
7759 ** different row of the same table using the [sqlite3_blob_reopen()]
7760 ** interface. However, the column, table, or database of a [BLOB handle]
7761 ** cannot be changed after the [BLOB handle] is opened.
7762 **
7763 ** ^(If the row that a BLOB handle points to is modified by an
7764 ** [UPDATE], [DELETE], or by [ON CONFLICT] side-effects
7765 ** then the BLOB handle is marked as "expired".
7766 ** This is true if any column of the row is changed, even a column
7767 ** other than the one the BLOB handle is open on.)^
7768 ** ^Calls to [sqlite3_blob_read()] and [sqlite3_blob_write()] for
7769 ** an expired BLOB handle fail with a return code of [SQLITE_ABORT].
7770 ** ^(Changes written into a BLOB prior to the BLOB expiring are not
7771 ** rolled back by the expiration of the BLOB. Such changes will eventually
7772 ** commit if the transaction continues to completion.)^
7773 **
7774 ** ^Use the [sqlite3_blob_bytes()] interface to determine the size of
7775 ** the opened blob. ^The size of a blob may not be changed by this
7776 ** interface. Use the [UPDATE] SQL command to change the size of a
7777 ** blob.
7778 **
7779 ** ^The [sqlite3_bind_zeroblob()] and [sqlite3_result_zeroblob()] interfaces
7780 ** and the built-in [zeroblob] SQL function may be used to create a
7781 ** zero-filled blob to read or write using the incremental-blob interface.
7782 **
7783 ** To avoid a resource leak, every open [BLOB handle] should eventually
7784 ** be released by a call to [sqlite3_blob_close()].
7785 **
7786 ** See also: [sqlite3_blob_close()],
7787 ** [sqlite3_blob_reopen()], [sqlite3_blob_read()],
7788 ** [sqlite3_blob_bytes()], [sqlite3_blob_write()].
7789 */
7790 SQLITE_API int sqlite3_blob_open(
7791 sqlite3*,
7792 const char *zDb,
7793 const char *zTable,
7794 const char *zColumn,
7795 sqlite3_int64 iRow,
7796 int flags,
7797 sqlite3_blob **ppBlob
7798 );
7799
7800 /*
7801 ** CAPI3REF: Move a BLOB Handle to a New Row
7802 ** METHOD: sqlite3_blob
7803 **
7804 ** ^This function is used to move an existing [BLOB handle] so that it points
7805 ** to a different row of the same database table. ^The new row is identified
7806 ** by the rowid value passed as the second argument. Only the row can be
7807 ** changed. ^The database, table and column on which the blob handle is open
7808 ** remain the same. Moving an existing [BLOB handle] to a new row is
7809 ** faster than closing the existing handle and opening a new one.
7810 **
7811 ** ^(The new row must meet the same criteria as for [sqlite3_blob_open()] -
7812 ** it must exist and there must be either a blob or text value stored in
7813 ** the nominated column.)^ ^If the new row is not present in the table, or if
7814 ** it does not contain a blob or text value, or if another error occurs, an
7815 ** SQLite error code is returned and the blob handle is considered aborted.
7816 ** ^All subsequent calls to [sqlite3_blob_read()], [sqlite3_blob_write()] or
7817 ** [sqlite3_blob_reopen()] on an aborted blob handle immediately return
7818 ** SQLITE_ABORT. ^Calling [sqlite3_blob_bytes()] on an aborted blob handle
7819 ** always returns zero.
7820 **
7821 ** ^This function sets the database handle error code and message.
7822 */
7823 SQLITE_API int sqlite3_blob_reopen(sqlite3_blob *, sqlite3_int64);
7824
7825 /*
7826 ** CAPI3REF: Close A BLOB Handle
7827 ** DESTRUCTOR: sqlite3_blob
7828 **
7829 ** ^This function closes an open [BLOB handle]. ^(The BLOB handle is closed
7830 ** unconditionally. Even if this routine returns an error code, the
7831 ** handle is still closed.)^
7832 **
7833 ** ^If the blob handle being closed was opened for read-write access, and if
7834 ** the database is in auto-commit mode and there are no other open read-write
7835 ** blob handles or active write statements, the current transaction is
7836 ** committed. ^If an error occurs while committing the transaction, an error
7837 ** code is returned and the transaction rolled back.
7838 **
7839 ** Calling this function with an argument that is not a NULL pointer or an
7840 ** open blob handle results in undefined behavior. ^Calling this routine
7841 ** with a null pointer (such as would be returned by a failed call to
7842 ** [sqlite3_blob_open()]) is a harmless no-op. ^Otherwise, if this function
7843 ** is passed a valid open blob handle, the values returned by the
7844 ** sqlite3_errcode() and sqlite3_errmsg() functions are set before returning.
7845 */
7846 SQLITE_API int sqlite3_blob_close(sqlite3_blob *);
7847
7848 /*
7849 ** CAPI3REF: Return The Size Of An Open BLOB
7850 ** METHOD: sqlite3_blob
7851 **
7852 ** ^Returns the size in bytes of the BLOB accessible via the
7853 ** successfully opened [BLOB handle] in its only argument. ^The
7854 ** incremental blob I/O routines can only read or overwriting existing
7855 ** blob content; they cannot change the size of a blob.
7856 **
7857 ** This routine only works on a [BLOB handle] which has been created
7858 ** by a prior successful call to [sqlite3_blob_open()] and which has not
7859 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in
7860 ** to this routine results in undefined and probably undesirable behavior.
7861 */
7862 SQLITE_API int sqlite3_blob_bytes(sqlite3_blob *);
7863
7864 /*
7865 ** CAPI3REF: Read Data From A BLOB Incrementally
7866 ** METHOD: sqlite3_blob
7867 **
7868 ** ^(This function is used to read data from an open [BLOB handle] into a
7869 ** caller-supplied buffer. N bytes of data are copied into buffer Z
7870 ** from the open BLOB, starting at offset iOffset.)^
7871 **
7872 ** ^If offset iOffset is less than N bytes from the end of the BLOB,
7873 ** [SQLITE_ERROR] is returned and no data is read. ^If N or iOffset is
7874 ** less than zero, [SQLITE_ERROR] is returned and no data is read.
7875 ** ^The size of the blob (and hence the maximum value of N+iOffset)
7876 ** can be determined using the [sqlite3_blob_bytes()] interface.
7877 **
7878 ** ^An attempt to read from an expired [BLOB handle] fails with an
7879 ** error code of [SQLITE_ABORT].
7880 **
7881 ** ^(On success, sqlite3_blob_read() returns SQLITE_OK.
7882 ** Otherwise, an [error code] or an [extended error code] is returned.)^
7883 **
7884 ** This routine only works on a [BLOB handle] which has been created
7885 ** by a prior successful call to [sqlite3_blob_open()] and which has not
7886 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in
7887 ** to this routine results in undefined and probably undesirable behavior.
7888 **
7889 ** See also: [sqlite3_blob_write()].
7890 */
7891 SQLITE_API int sqlite3_blob_read(sqlite3_blob *, void *Z, int N, int iOffset);
7892
7893 /*
7894 ** CAPI3REF: Write Data Into A BLOB Incrementally
7895 ** METHOD: sqlite3_blob
7896 **
7897 ** ^(This function is used to write data into an open [BLOB handle] from a
7898 ** caller-supplied buffer. N bytes of data are copied from the buffer Z
7899 ** into the open BLOB, starting at offset iOffset.)^
7900 **
7901 ** ^(On success, sqlite3_blob_write() returns SQLITE_OK.
7902 ** Otherwise, an [error code] or an [extended error code] is returned.)^
7903 ** ^Unless SQLITE_MISUSE is returned, this function sets the
7904 ** [database connection] error code and message accessible via
7905 ** [sqlite3_errcode()] and [sqlite3_errmsg()] and related functions.
7906 **
7907 ** ^If the [BLOB handle] passed as the first argument was not opened for
7908 ** writing (the flags parameter to [sqlite3_blob_open()] was zero),
7909 ** this function returns [SQLITE_READONLY].
7910 **
7911 ** This function may only modify the contents of the BLOB; it is
7912 ** not possible to increase the size of a BLOB using this API.
7913 ** ^If offset iOffset is less than N bytes from the end of the BLOB,
7914 ** [SQLITE_ERROR] is returned and no data is written. The size of the
7915 ** BLOB (and hence the maximum value of N+iOffset) can be determined
7916 ** using the [sqlite3_blob_bytes()] interface. ^If N or iOffset are less
7917 ** than zero [SQLITE_ERROR] is returned and no data is written.
7918 **
7919 ** ^An attempt to write to an expired [BLOB handle] fails with an
7920 ** error code of [SQLITE_ABORT]. ^Writes to the BLOB that occurred
7921 ** before the [BLOB handle] expired are not rolled back by the
7922 ** expiration of the handle, though of course those changes might
7923 ** have been overwritten by the statement that expired the BLOB handle
7924 ** or by other independent statements.
7925 **
7926 ** This routine only works on a [BLOB handle] which has been created
7927 ** by a prior successful call to [sqlite3_blob_open()] and which has not
7928 ** been closed by [sqlite3_blob_close()]. Passing any other pointer in
7929 ** to this routine results in undefined and probably undesirable behavior.
7930 **
7931 ** See also: [sqlite3_blob_read()].
7932 */
7933 SQLITE_API int sqlite3_blob_write(sqlite3_blob *, const void *z, int n, int iOffset);
7934
7935 /*
7936 ** CAPI3REF: Virtual File System Objects
7937 **
7938 ** A virtual filesystem (VFS) is an [sqlite3_vfs] object
7939 ** that SQLite uses to interact
7940 ** with the underlying operating system. Most SQLite builds come with a
7941 ** single default VFS that is appropriate for the host computer.
7942 ** New VFSes can be registered and existing VFSes can be unregistered.
7943 ** The following interfaces are provided.
7944 **
7945 ** ^The sqlite3_vfs_find() interface returns a pointer to a VFS given its name.
7946 ** ^Names are case sensitive.
7947 ** ^Names are zero-terminated UTF-8 strings.
7948 ** ^If there is no match, a NULL pointer is returned.
7949 ** ^If zVfsName is NULL then the default VFS is returned.
7950 **
7951 ** ^New VFSes are registered with sqlite3_vfs_register().
7952 ** ^Each new VFS becomes the default VFS if the makeDflt flag is set.
7953 ** ^The same VFS can be registered multiple times without injury.
7954 ** ^To make an existing VFS into the default VFS, register it again
7955 ** with the makeDflt flag set. If two different VFSes with the
7956 ** same name are registered, the behavior is undefined. If a
7957 ** VFS is registered with a name that is NULL or an empty string,
7958 ** then the behavior is undefined.
7959 **
7960 ** ^Unregister a VFS with the sqlite3_vfs_unregister() interface.
7961 ** ^(If the default VFS is unregistered, another VFS is chosen as
7962 ** the default. The choice for the new VFS is arbitrary.)^
7963 */
7964 SQLITE_API sqlite3_vfs *sqlite3_vfs_find(const char *zVfsName);
7965 SQLITE_API int sqlite3_vfs_register(sqlite3_vfs*, int makeDflt);
7966 SQLITE_API int sqlite3_vfs_unregister(sqlite3_vfs*);
7967
7968 /*
7969 ** CAPI3REF: Mutexes
7970 **
7971 ** The SQLite core uses these routines for thread
7972 ** synchronization. Though they are intended for internal
7973 ** use by SQLite, code that links against SQLite is
7974 ** permitted to use any of these routines.
7975 **
7976 ** The SQLite source code contains multiple implementations
7977 ** of these mutex routines. An appropriate implementation
7978 ** is selected automatically at compile-time. The following
7979 ** implementations are available in the SQLite core:
7980 **
7981 ** <ul>
7982 ** <li> SQLITE_MUTEX_PTHREADS
7983 ** <li> SQLITE_MUTEX_W32
7984 ** <li> SQLITE_MUTEX_NOOP
7985 ** </ul>
7986 **
7987 ** The SQLITE_MUTEX_NOOP implementation is a set of routines
7988 ** that does no real locking and is appropriate for use in
7989 ** a single-threaded application. The SQLITE_MUTEX_PTHREADS and
7990 ** SQLITE_MUTEX_W32 implementations are appropriate for use on Unix
7991 ** and Windows.
7992 **
7993 ** If SQLite is compiled with the SQLITE_MUTEX_APPDEF preprocessor
7994 ** macro defined (with "-DSQLITE_MUTEX_APPDEF=1"), then no mutex
7995 ** implementation is included with the library. In this case the
7996 ** application must supply a custom mutex implementation using the
7997 ** [SQLITE_CONFIG_MUTEX] option of the sqlite3_config() function
7998 ** before calling sqlite3_initialize() or any other public sqlite3_
7999 ** function that calls sqlite3_initialize().
8000 **
8001 ** ^The sqlite3_mutex_alloc() routine allocates a new
8002 ** mutex and returns a pointer to it. ^The sqlite3_mutex_alloc()
8003 ** routine returns NULL if it is unable to allocate the requested
8004 ** mutex. The argument to sqlite3_mutex_alloc() must one of these
8005 ** integer constants:
8006 **
8007 ** <ul>
8008 ** <li> SQLITE_MUTEX_FAST
8009 ** <li> SQLITE_MUTEX_RECURSIVE
8010 ** <li> SQLITE_MUTEX_STATIC_MAIN
8011 ** <li> SQLITE_MUTEX_STATIC_MEM
8012 ** <li> SQLITE_MUTEX_STATIC_OPEN
8013 ** <li> SQLITE_MUTEX_STATIC_PRNG
8014 ** <li> SQLITE_MUTEX_STATIC_LRU
8015 ** <li> SQLITE_MUTEX_STATIC_PMEM
8016 ** <li> SQLITE_MUTEX_STATIC_APP1
8017 ** <li> SQLITE_MUTEX_STATIC_APP2
8018 ** <li> SQLITE_MUTEX_STATIC_APP3
8019 ** <li> SQLITE_MUTEX_STATIC_VFS1
8020 ** <li> SQLITE_MUTEX_STATIC_VFS2
8021 ** <li> SQLITE_MUTEX_STATIC_VFS3
8022 ** </ul>
8023 **
8024 ** ^The first two constants (SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE)
8025 ** cause sqlite3_mutex_alloc() to create
8026 ** a new mutex. ^The new mutex is recursive when SQLITE_MUTEX_RECURSIVE
8027 ** is used but not necessarily so when SQLITE_MUTEX_FAST is used.
8028 ** The mutex implementation does not need to make a distinction
8029 ** between SQLITE_MUTEX_RECURSIVE and SQLITE_MUTEX_FAST if it does
8030 ** not want to. SQLite will only request a recursive mutex in
8031 ** cases where it really needs one. If a faster non-recursive mutex
8032 ** implementation is available on the host platform, the mutex subsystem
8033 ** might return such a mutex in response to SQLITE_MUTEX_FAST.
8034 **
8035 ** ^The other allowed parameters to sqlite3_mutex_alloc() (anything other
8036 ** than SQLITE_MUTEX_FAST and SQLITE_MUTEX_RECURSIVE) each return
8037 ** a pointer to a static preexisting mutex. ^Nine static mutexes are
8038 ** used by the current version of SQLite. Future versions of SQLite
8039 ** may add additional static mutexes. Static mutexes are for internal
8040 ** use by SQLite only. Applications that use SQLite mutexes should
8041 ** use only the dynamic mutexes returned by SQLITE_MUTEX_FAST or
8042 ** SQLITE_MUTEX_RECURSIVE.
8043 **
8044 ** ^Note that if one of the dynamic mutex parameters (SQLITE_MUTEX_FAST
8045 ** or SQLITE_MUTEX_RECURSIVE) is used then sqlite3_mutex_alloc()
8046 ** returns a different mutex on every call. ^For the static
8047 ** mutex types, the same mutex is returned on every call that has
8048 ** the same type number.
8049 **
8050 ** ^The sqlite3_mutex_free() routine deallocates a previously
8051 ** allocated dynamic mutex. Attempting to deallocate a static
8052 ** mutex results in undefined behavior.
8053 **
8054 ** ^The sqlite3_mutex_enter() and sqlite3_mutex_try() routines attempt
8055 ** to enter a mutex. ^If another thread is already within the mutex,
8056 ** sqlite3_mutex_enter() will block and sqlite3_mutex_try() will return
8057 ** SQLITE_BUSY. ^The sqlite3_mutex_try() interface returns [SQLITE_OK]
8058 ** upon successful entry. ^(Mutexes created using
8059 ** SQLITE_MUTEX_RECURSIVE can be entered multiple times by the same thread.
8060 ** In such cases, the
8061 ** mutex must be exited an equal number of times before another thread
8062 ** can enter.)^ If the same thread tries to enter any mutex other
8063 ** than an SQLITE_MUTEX_RECURSIVE more than once, the behavior is undefined.
8064 **
8065 ** ^(Some systems (for example, Windows 95) do not support the operation
8066 ** implemented by sqlite3_mutex_try(). On those systems, sqlite3_mutex_try()
8067 ** will always return SQLITE_BUSY. In most cases the SQLite core only uses
8068 ** sqlite3_mutex_try() as an optimization, so this is acceptable
8069 ** behavior. The exceptions are unix builds that set the
8070 ** SQLITE_ENABLE_SETLK_TIMEOUT build option. In that case a working
8071 ** sqlite3_mutex_try() is required.)^
8072 **
8073 ** ^The sqlite3_mutex_leave() routine exits a mutex that was
8074 ** previously entered by the same thread. The behavior
8075 ** is undefined if the mutex is not currently entered by the
8076 ** calling thread or is not currently allocated.
8077 **
8078 ** ^If the argument to sqlite3_mutex_enter(), sqlite3_mutex_try(),
8079 ** sqlite3_mutex_leave(), or sqlite3_mutex_free() is a NULL pointer,
8080 ** then any of the four routines behaves as a no-op.
8081 **
8082 ** See also: [sqlite3_mutex_held()] and [sqlite3_mutex_notheld()].
8083 */
8084 SQLITE_API sqlite3_mutex *sqlite3_mutex_alloc(int);
8085 SQLITE_API void sqlite3_mutex_free(sqlite3_mutex*);
8086 SQLITE_API void sqlite3_mutex_enter(sqlite3_mutex*);
8087 SQLITE_API int sqlite3_mutex_try(sqlite3_mutex*);
8088 SQLITE_API void sqlite3_mutex_leave(sqlite3_mutex*);
8089
8090 /*
8091 ** CAPI3REF: Mutex Methods Object
8092 **
8093 ** An instance of this structure defines the low-level routines
8094 ** used to allocate and use mutexes.
8095 **
8096 ** Usually, the default mutex implementations provided by SQLite are
8097 ** sufficient, however the application has the option of substituting a custom
8098 ** implementation for specialized deployments or systems for which SQLite
8099 ** does not provide a suitable implementation. In this case, the application
8100 ** creates and populates an instance of this structure to pass
8101 ** to sqlite3_config() along with the [SQLITE_CONFIG_MUTEX] option.
8102 ** Additionally, an instance of this structure can be used as an
8103 ** output variable when querying the system for the current mutex
8104 ** implementation, using the [SQLITE_CONFIG_GETMUTEX] option.
8105 **
8106 ** ^The xMutexInit method defined by this structure is invoked as
8107 ** part of system initialization by the sqlite3_initialize() function.
8108 ** ^The xMutexInit routine is called by SQLite exactly once for each
8109 ** effective call to [sqlite3_initialize()].
8110 **
8111 ** ^The xMutexEnd method defined by this structure is invoked as
8112 ** part of system shutdown by the sqlite3_shutdown() function. The
8113 ** implementation of this method is expected to release all outstanding
8114 ** resources obtained by the mutex methods implementation, especially
8115 ** those obtained by the xMutexInit method. ^The xMutexEnd()
8116 ** interface is invoked exactly once for each call to [sqlite3_shutdown()].
8117 **
8118 ** ^(The remaining seven methods defined by this structure (xMutexAlloc,
8119 ** xMutexFree, xMutexEnter, xMutexTry, xMutexLeave, xMutexHeld and
8120 ** xMutexNotheld) implement the following interfaces (respectively):
8121 **
8122 ** <ul>
8123 ** <li> [sqlite3_mutex_alloc()] </li>
8124 ** <li> [sqlite3_mutex_free()] </li>
8125 ** <li> [sqlite3_mutex_enter()] </li>
8126 ** <li> [sqlite3_mutex_try()] </li>
8127 ** <li> [sqlite3_mutex_leave()] </li>
8128 ** <li> [sqlite3_mutex_held()] </li>
8129 ** <li> [sqlite3_mutex_notheld()] </li>
8130 ** </ul>)^
8131 **
8132 ** The only difference is that the public sqlite3_XXX functions enumerated
8133 ** above silently ignore any invocations that pass a NULL pointer instead
8134 ** of a valid mutex handle. The implementations of the methods defined
8135 ** by this structure are not required to handle this case. The results
8136 ** of passing a NULL pointer instead of a valid mutex handle are undefined
8137 ** (i.e. it is acceptable to provide an implementation that segfaults if
8138 ** it is passed a NULL pointer).
8139 **
8140 ** The xMutexInit() method must be threadsafe. It must be harmless to
8141 ** invoke xMutexInit() multiple times within the same process and without
8142 ** intervening calls to xMutexEnd(). Second and subsequent calls to
8143 ** xMutexInit() must be no-ops.
8144 **
8145 ** xMutexInit() must not use SQLite memory allocation ([sqlite3_malloc()]
8146 ** and its associates). Similarly, xMutexAlloc() must not use SQLite memory
8147 ** allocation for a static mutex. ^However xMutexAlloc() may use SQLite
8148 ** memory allocation for a fast or recursive mutex.
8149 **
8150 ** ^SQLite will invoke the xMutexEnd() method when [sqlite3_shutdown()] is
8151 ** called, but only if the prior call to xMutexInit returned SQLITE_OK.
8152 ** If xMutexInit fails in any way, it is expected to clean up after itself
8153 ** prior to returning.
8154 */
8155 typedef struct sqlite3_mutex_methods sqlite3_mutex_methods;
8156 struct sqlite3_mutex_methods {
8157 int (*xMutexInit)(void);
8158 int (*xMutexEnd)(void);
8159 sqlite3_mutex *(*xMutexAlloc)(int);
8160 void (*xMutexFree)(sqlite3_mutex *);
8161 void (*xMutexEnter)(sqlite3_mutex *);
8162 int (*xMutexTry)(sqlite3_mutex *);
8163 void (*xMutexLeave)(sqlite3_mutex *);
8164 int (*xMutexHeld)(sqlite3_mutex *);
8165 int (*xMutexNotheld)(sqlite3_mutex *);
8166 };
8167
8168 /*
8169 ** CAPI3REF: Mutex Verification Routines
8170 **
8171 ** The sqlite3_mutex_held() and sqlite3_mutex_notheld() routines
8172 ** are intended for use inside assert() statements. The SQLite core
8173 ** never uses these routines except inside an assert() and applications
8174 ** are advised to follow the lead of the core. The SQLite core only
8175 ** provides implementations for these routines when it is compiled
8176 ** with the SQLITE_DEBUG flag. External mutex implementations
8177 ** are only required to provide these routines if SQLITE_DEBUG is
8178 ** defined and if NDEBUG is not defined.
8179 **
8180 ** These routines should return true if the mutex in their argument
8181 ** is held or not held, respectively, by the calling thread.
8182 **
8183 ** The implementation is not required to provide versions of these
8184 ** routines that actually work. If the implementation does not provide working
8185 ** versions of these routines, it should at least provide stubs that always
8186 ** return true so that one does not get spurious assertion failures.
8187 **
8188 ** If the argument to sqlite3_mutex_held() is a NULL pointer then
8189 ** the routine should return 1. This seems counter-intuitive since
8190 ** clearly the mutex cannot be held if it does not exist. But
8191 ** the reason the mutex does not exist is because the build is not
8192 ** using mutexes. And we do not want the assert() containing the
8193 ** call to sqlite3_mutex_held() to fail, so a non-zero return is
8194 ** the appropriate thing to do. The sqlite3_mutex_notheld()
8195 ** interface should also return 1 when given a NULL pointer.
8196 */
8197 #ifndef NDEBUG
8198 SQLITE_API int sqlite3_mutex_held(sqlite3_mutex*);
8199 SQLITE_API int sqlite3_mutex_notheld(sqlite3_mutex*);
8200 #endif
8201
8202 /*
8203 ** CAPI3REF: Mutex Types
8204 **
8205 ** The [sqlite3_mutex_alloc()] interface takes a single argument
8206 ** which is one of these integer constants.
8207 **
8208 ** The set of static mutexes may change from one SQLite release to the
8209 ** next. Applications that override the built-in mutex logic must be
8210 ** prepared to accommodate additional static mutexes.
8211 */
8212 #define SQLITE_MUTEX_FAST 0
8213 #define SQLITE_MUTEX_RECURSIVE 1
8214 #define SQLITE_MUTEX_STATIC_MAIN 2
8215 #define SQLITE_MUTEX_STATIC_MEM 3 /* sqlite3_malloc() */
8216 #define SQLITE_MUTEX_STATIC_MEM2 4 /* NOT USED */
8217 #define SQLITE_MUTEX_STATIC_OPEN 4 /* sqlite3BtreeOpen() */
8218 #define SQLITE_MUTEX_STATIC_PRNG 5 /* sqlite3_randomness() */
8219 #define SQLITE_MUTEX_STATIC_LRU 6 /* lru page list */
8220 #define SQLITE_MUTEX_STATIC_LRU2 7 /* NOT USED */
8221 #define SQLITE_MUTEX_STATIC_PMEM 7 /* sqlite3PageMalloc() */
8222 #define SQLITE_MUTEX_STATIC_APP1 8 /* For use by application */
8223 #define SQLITE_MUTEX_STATIC_APP2 9 /* For use by application */
8224 #define SQLITE_MUTEX_STATIC_APP3 10 /* For use by application */
8225 #define SQLITE_MUTEX_STATIC_VFS1 11 /* For use by built-in VFS */
8226 #define SQLITE_MUTEX_STATIC_VFS2 12 /* For use by extension VFS */
8227 #define SQLITE_MUTEX_STATIC_VFS3 13 /* For use by application VFS */
8228
8229 /* Legacy compatibility: */
8230 #define SQLITE_MUTEX_STATIC_MASTER 2
8231
8232
8233 /*
8234 ** CAPI3REF: Retrieve the mutex for a database connection
8235 ** METHOD: sqlite3
8236 **
8237 ** ^This interface returns a pointer the [sqlite3_mutex] object that
8238 ** serializes access to the [database connection] given in the argument
8239 ** when the [threading mode] is Serialized.
8240 ** ^If the [threading mode] is Single-thread or Multi-thread then this
8241 ** routine returns a NULL pointer.
8242 */
8243 SQLITE_API sqlite3_mutex *sqlite3_db_mutex(sqlite3*);
8244
8245 /*
8246 ** CAPI3REF: Low-Level Control Of Database Files
8247 ** METHOD: sqlite3
8248 ** KEYWORDS: {file control}
8249 **
8250 ** ^The [sqlite3_file_control()] interface makes a direct call to the
8251 ** xFileControl method for the [sqlite3_io_methods] object associated
8252 ** with a particular database identified by the second argument. ^The
8253 ** name of the database is "main" for the main database or "temp" for the
8254 ** TEMP database, or the name that appears after the AS keyword for
8255 ** databases that are added using the [ATTACH] SQL command.
8256 ** ^A NULL pointer can be used in place of "main" to refer to the
8257 ** main database file.
8258 ** ^The third and fourth parameters to this routine
8259 ** are passed directly through to the second and third parameters of
8260 ** the xFileControl method. ^The return value of the xFileControl
8261 ** method becomes the return value of this routine.
8262 **
8263 ** A few opcodes for [sqlite3_file_control()] are handled directly
8264 ** by the SQLite core and never invoke the
8265 ** sqlite3_io_methods.xFileControl method.
8266 ** ^The [SQLITE_FCNTL_FILE_POINTER] value for the op parameter causes
8267 ** a pointer to the underlying [sqlite3_file] object to be written into
8268 ** the space pointed to by the 4th parameter. The
8269 ** [SQLITE_FCNTL_JOURNAL_POINTER] works similarly except that it returns
8270 ** the [sqlite3_file] object associated with the journal file instead of
8271 ** the main database. The [SQLITE_FCNTL_VFS_POINTER] opcode returns
8272 ** a pointer to the underlying [sqlite3_vfs] object for the file.
8273 ** The [SQLITE_FCNTL_DATA_VERSION] returns the data version counter
8274 ** from the pager.
8275 **
8276 ** ^If the second parameter (zDbName) does not match the name of any
8277 ** open database file, then SQLITE_ERROR is returned. ^This error
8278 ** code is not remembered and will not be recalled by [sqlite3_errcode()]
8279 ** or [sqlite3_errmsg()]. The underlying xFileControl method might
8280 ** also return SQLITE_ERROR. There is no way to distinguish between
8281 ** an incorrect zDbName and an SQLITE_ERROR return from the underlying
8282 ** xFileControl method.
8283 **
8284 ** See also: [file control opcodes]
8285 */
8286 SQLITE_API int sqlite3_file_control(sqlite3*, const char *zDbName, int op, void*);
8287
8288 /*
8289 ** CAPI3REF: Testing Interface
8290 **
8291 ** ^The sqlite3_test_control() interface is used to read out internal
8292 ** state of SQLite and to inject faults into SQLite for testing
8293 ** purposes. ^The first parameter is an operation code that determines
8294 ** the number, meaning, and operation of all subsequent parameters.
8295 **
8296 ** This interface is not for use by applications. It exists solely
8297 ** for verifying the correct operation of the SQLite library. Depending
8298 ** on how the SQLite library is compiled, this interface might not exist.
8299 **
8300 ** The details of the operation codes, their meanings, the parameters
8301 ** they take, and what they do are all subject to change without notice.
8302 ** Unlike most of the SQLite API, this function is not guaranteed to
8303 ** operate consistently from one release to the next.
8304 */
8305 SQLITE_API int sqlite3_test_control(int op, ...);
8306
8307 /*
8308 ** CAPI3REF: Testing Interface Operation Codes
8309 **
8310 ** These constants are the valid operation code parameters used
8311 ** as the first argument to [sqlite3_test_control()].
8312 **
8313 ** These parameters and their meanings are subject to change
8314 ** without notice. These values are for testing purposes only.
8315 ** Applications should not use any of these parameters or the
8316 ** [sqlite3_test_control()] interface.
8317 */
8318 #define SQLITE_TESTCTRL_FIRST 5
8319 #define SQLITE_TESTCTRL_PRNG_SAVE 5
8320 #define SQLITE_TESTCTRL_PRNG_RESTORE 6
8321 #define SQLITE_TESTCTRL_PRNG_RESET 7 /* NOT USED */
8322 #define SQLITE_TESTCTRL_FK_NO_ACTION 7
8323 #define SQLITE_TESTCTRL_BITVEC_TEST 8
8324 #define SQLITE_TESTCTRL_FAULT_INSTALL 9
8325 #define SQLITE_TESTCTRL_BENIGN_MALLOC_HOOKS 10
8326 #define SQLITE_TESTCTRL_PENDING_BYTE 11
8327 #define SQLITE_TESTCTRL_ASSERT 12
8328 #define SQLITE_TESTCTRL_ALWAYS 13
8329 #define SQLITE_TESTCTRL_RESERVE 14 /* NOT USED */
8330 #define SQLITE_TESTCTRL_JSON_SELFCHECK 14
8331 #define SQLITE_TESTCTRL_OPTIMIZATIONS 15
8332 #define SQLITE_TESTCTRL_ISKEYWORD 16 /* NOT USED */
8333 #define SQLITE_TESTCTRL_SCRATCHMALLOC 17 /* NOT USED */
8334 #define SQLITE_TESTCTRL_INTERNAL_FUNCTIONS 17
8335 #define SQLITE_TESTCTRL_LOCALTIME_FAULT 18
8336 #define SQLITE_TESTCTRL_EXPLAIN_STMT 19 /* NOT USED */
8337 #define SQLITE_TESTCTRL_ONCE_RESET_THRESHOLD 19
8338 #define SQLITE_TESTCTRL_NEVER_CORRUPT 20
8339 #define SQLITE_TESTCTRL_VDBE_COVERAGE 21
8340 #define SQLITE_TESTCTRL_BYTEORDER 22
8341 #define SQLITE_TESTCTRL_ISINIT 23
8342 #define SQLITE_TESTCTRL_SORTER_MMAP 24
8343 #define SQLITE_TESTCTRL_IMPOSTER 25
8344 #define SQLITE_TESTCTRL_PARSER_COVERAGE 26
8345 #define SQLITE_TESTCTRL_RESULT_INTREAL 27
8346 #define SQLITE_TESTCTRL_PRNG_SEED 28
8347 #define SQLITE_TESTCTRL_EXTRA_SCHEMA_CHECKS 29
8348 #define SQLITE_TESTCTRL_SEEK_COUNT 30
8349 #define SQLITE_TESTCTRL_TRACEFLAGS 31
8350 #define SQLITE_TESTCTRL_TUNE 32
8351 #define SQLITE_TESTCTRL_LOGEST 33
8352 #define SQLITE_TESTCTRL_USELONGDOUBLE 34
8353 #define SQLITE_TESTCTRL_LAST 34 /* Largest TESTCTRL */
8354
8355 /*
8356 ** CAPI3REF: SQL Keyword Checking
8357 **
8358 ** These routines provide access to the set of SQL language keywords
8359 ** recognized by SQLite. Applications can uses these routines to determine
8360 ** whether or not a specific identifier needs to be escaped (for example,
8361 ** by enclosing in double-quotes) so as not to confuse the parser.
8362 **
8363 ** The sqlite3_keyword_count() interface returns the number of distinct
8364 ** keywords understood by SQLite.
8365 **
8366 ** The sqlite3_keyword_name(N,Z,L) interface finds the 0-based N-th keyword and
8367 ** makes *Z point to that keyword expressed as UTF8 and writes the number
8368 ** of bytes in the keyword into *L. The string that *Z points to is not
8369 ** zero-terminated. The sqlite3_keyword_name(N,Z,L) routine returns
8370 ** SQLITE_OK if N is within bounds and SQLITE_ERROR if not. If either Z
8371 ** or L are NULL or invalid pointers then calls to
8372 ** sqlite3_keyword_name(N,Z,L) result in undefined behavior.
8373 **
8374 ** The sqlite3_keyword_check(Z,L) interface checks to see whether or not
8375 ** the L-byte UTF8 identifier that Z points to is a keyword, returning non-zero
8376 ** if it is and zero if not.
8377 **
8378 ** The parser used by SQLite is forgiving. It is often possible to use
8379 ** a keyword as an identifier as long as such use does not result in a
8380 ** parsing ambiguity. For example, the statement
8381 ** "CREATE TABLE BEGIN(REPLACE,PRAGMA,END);" is accepted by SQLite, and
8382 ** creates a new table named "BEGIN" with three columns named
8383 ** "REPLACE", "PRAGMA", and "END". Nevertheless, best practice is to avoid
8384 ** using keywords as identifiers. Common techniques used to avoid keyword
8385 ** name collisions include:
8386 ** <ul>
8387 ** <li> Put all identifier names inside double-quotes. This is the official
8388 ** SQL way to escape identifier names.
8389 ** <li> Put identifier names inside &#91;...&#93;. This is not standard SQL,
8390 ** but it is what SQL Server does and so lots of programmers use this
8391 ** technique.
8392 ** <li> Begin every identifier with the letter "Z" as no SQL keywords start
8393 ** with "Z".
8394 ** <li> Include a digit somewhere in every identifier name.
8395 ** </ul>
8396 **
8397 ** Note that the number of keywords understood by SQLite can depend on
8398 ** compile-time options. For example, "VACUUM" is not a keyword if
8399 ** SQLite is compiled with the [-DSQLITE_OMIT_VACUUM] option. Also,
8400 ** new keywords may be added to future releases of SQLite.
8401 */
8402 SQLITE_API int sqlite3_keyword_count(void);
8403 SQLITE_API int sqlite3_keyword_name(int,const char**,int*);
8404 SQLITE_API int sqlite3_keyword_check(const char*,int);
8405
8406 /*
8407 ** CAPI3REF: Dynamic String Object
8408 ** KEYWORDS: {dynamic string}
8409 **
8410 ** An instance of the sqlite3_str object contains a dynamically-sized
8411 ** string under construction.
8412 **
8413 ** The lifecycle of an sqlite3_str object is as follows:
8414 ** <ol>
8415 ** <li> ^The sqlite3_str object is created using [sqlite3_str_new()].
8416 ** <li> ^Text is appended to the sqlite3_str object using various
8417 ** methods, such as [sqlite3_str_appendf()].
8418 ** <li> ^The sqlite3_str object is destroyed and the string it created
8419 ** is returned using the [sqlite3_str_finish()] interface.
8420 ** </ol>
8421 */
8422 typedef struct sqlite3_str sqlite3_str;
8423
8424 /*
8425 ** CAPI3REF: Create A New Dynamic String Object
8426 ** CONSTRUCTOR: sqlite3_str
8427 **
8428 ** ^The [sqlite3_str_new(D)] interface allocates and initializes
8429 ** a new [sqlite3_str] object. To avoid memory leaks, the object returned by
8430 ** [sqlite3_str_new()] must be freed by a subsequent call to
8431 ** [sqlite3_str_finish(X)].
8432 **
8433 ** ^The [sqlite3_str_new(D)] interface always returns a pointer to a
8434 ** valid [sqlite3_str] object, though in the event of an out-of-memory
8435 ** error the returned object might be a special singleton that will
8436 ** silently reject new text, always return SQLITE_NOMEM from
8437 ** [sqlite3_str_errcode()], always return 0 for
8438 ** [sqlite3_str_length()], and always return NULL from
8439 ** [sqlite3_str_finish(X)]. It is always safe to use the value
8440 ** returned by [sqlite3_str_new(D)] as the sqlite3_str parameter
8441 ** to any of the other [sqlite3_str] methods.
8442 **
8443 ** The D parameter to [sqlite3_str_new(D)] may be NULL. If the
8444 ** D parameter in [sqlite3_str_new(D)] is not NULL, then the maximum
8445 ** length of the string contained in the [sqlite3_str] object will be
8446 ** the value set for [sqlite3_limit](D,[SQLITE_LIMIT_LENGTH]) instead
8447 ** of [SQLITE_MAX_LENGTH].
8448 */
8449 SQLITE_API sqlite3_str *sqlite3_str_new(sqlite3*);
8450
8451 /*
8452 ** CAPI3REF: Finalize A Dynamic String
8453 ** DESTRUCTOR: sqlite3_str
8454 **
8455 ** ^The [sqlite3_str_finish(X)] interface destroys the sqlite3_str object X
8456 ** and returns a pointer to a memory buffer obtained from [sqlite3_malloc64()]
8457 ** that contains the constructed string. The calling application should
8458 ** pass the returned value to [sqlite3_free()] to avoid a memory leak.
8459 ** ^The [sqlite3_str_finish(X)] interface may return a NULL pointer if any
8460 ** errors were encountered during construction of the string. ^The
8461 ** [sqlite3_str_finish(X)] interface will also return a NULL pointer if the
8462 ** string in [sqlite3_str] object X is zero bytes long.
8463 */
8464 SQLITE_API char *sqlite3_str_finish(sqlite3_str*);
8465
8466 /*
8467 ** CAPI3REF: Add Content To A Dynamic String
8468 ** METHOD: sqlite3_str
8469 **
8470 ** These interfaces add content to an sqlite3_str object previously obtained
8471 ** from [sqlite3_str_new()].
8472 **
8473 ** ^The [sqlite3_str_appendf(X,F,...)] and
8474 ** [sqlite3_str_vappendf(X,F,V)] interfaces uses the [built-in printf]
8475 ** functionality of SQLite to append formatted text onto the end of
8476 ** [sqlite3_str] object X.
8477 **
8478 ** ^The [sqlite3_str_append(X,S,N)] method appends exactly N bytes from string S
8479 ** onto the end of the [sqlite3_str] object X. N must be non-negative.
8480 ** S must contain at least N non-zero bytes of content. To append a
8481 ** zero-terminated string in its entirety, use the [sqlite3_str_appendall()]
8482 ** method instead.
8483 **
8484 ** ^The [sqlite3_str_appendall(X,S)] method appends the complete content of
8485 ** zero-terminated string S onto the end of [sqlite3_str] object X.
8486 **
8487 ** ^The [sqlite3_str_appendchar(X,N,C)] method appends N copies of the
8488 ** single-byte character C onto the end of [sqlite3_str] object X.
8489 ** ^This method can be used, for example, to add whitespace indentation.
8490 **
8491 ** ^The [sqlite3_str_reset(X)] method resets the string under construction
8492 ** inside [sqlite3_str] object X back to zero bytes in length.
8493 **
8494 ** These methods do not return a result code. ^If an error occurs, that fact
8495 ** is recorded in the [sqlite3_str] object and can be recovered by a
8496 ** subsequent call to [sqlite3_str_errcode(X)].
8497 */
8498 SQLITE_API void sqlite3_str_appendf(sqlite3_str*, const char *zFormat, ...);
8499 SQLITE_API void sqlite3_str_vappendf(sqlite3_str*, const char *zFormat, va_list);
8500 SQLITE_API void sqlite3_str_append(sqlite3_str*, const char *zIn, int N);
8501 SQLITE_API void sqlite3_str_appendall(sqlite3_str*, const char *zIn);
8502 SQLITE_API void sqlite3_str_appendchar(sqlite3_str*, int N, char C);
8503 SQLITE_API void sqlite3_str_reset(sqlite3_str*);
8504
8505 /*
8506 ** CAPI3REF: Status Of A Dynamic String
8507 ** METHOD: sqlite3_str
8508 **
8509 ** These interfaces return the current status of an [sqlite3_str] object.
8510 **
8511 ** ^If any prior errors have occurred while constructing the dynamic string
8512 ** in sqlite3_str X, then the [sqlite3_str_errcode(X)] method will return
8513 ** an appropriate error code. ^The [sqlite3_str_errcode(X)] method returns
8514 ** [SQLITE_NOMEM] following any out-of-memory error, or
8515 ** [SQLITE_TOOBIG] if the size of the dynamic string exceeds
8516 ** [SQLITE_MAX_LENGTH], or [SQLITE_OK] if there have been no errors.
8517 **
8518 ** ^The [sqlite3_str_length(X)] method returns the current length, in bytes,
8519 ** of the dynamic string under construction in [sqlite3_str] object X.
8520 ** ^The length returned by [sqlite3_str_length(X)] does not include the
8521 ** zero-termination byte.
8522 **
8523 ** ^The [sqlite3_str_value(X)] method returns a pointer to the current
8524 ** content of the dynamic string under construction in X. The value
8525 ** returned by [sqlite3_str_value(X)] is managed by the sqlite3_str object X
8526 ** and might be freed or altered by any subsequent method on the same
8527 ** [sqlite3_str] object. Applications must not used the pointer returned
8528 ** [sqlite3_str_value(X)] after any subsequent method call on the same
8529 ** object. ^Applications may change the content of the string returned
8530 ** by [sqlite3_str_value(X)] as long as they do not write into any bytes
8531 ** outside the range of 0 to [sqlite3_str_length(X)] and do not read or
8532 ** write any byte after any subsequent sqlite3_str method call.
8533 */
8534 SQLITE_API int sqlite3_str_errcode(sqlite3_str*);
8535 SQLITE_API int sqlite3_str_length(sqlite3_str*);
8536 SQLITE_API char *sqlite3_str_value(sqlite3_str*);
8537
8538 /*
8539 ** CAPI3REF: SQLite Runtime Status
8540 **
8541 ** ^These interfaces are used to retrieve runtime status information
8542 ** about the performance of SQLite, and optionally to reset various
8543 ** highwater marks. ^The first argument is an integer code for
8544 ** the specific parameter to measure. ^(Recognized integer codes
8545 ** are of the form [status parameters | SQLITE_STATUS_...].)^
8546 ** ^The current value of the parameter is returned into *pCurrent.
8547 ** ^The highest recorded value is returned in *pHighwater. ^If the
8548 ** resetFlag is true, then the highest record value is reset after
8549 ** *pHighwater is written. ^(Some parameters do not record the highest
8550 ** value. For those parameters
8551 ** nothing is written into *pHighwater and the resetFlag is ignored.)^
8552 ** ^(Other parameters record only the highwater mark and not the current
8553 ** value. For these latter parameters nothing is written into *pCurrent.)^
8554 **
8555 ** ^The sqlite3_status() and sqlite3_status64() routines return
8556 ** SQLITE_OK on success and a non-zero [error code] on failure.
8557 **
8558 ** If either the current value or the highwater mark is too large to
8559 ** be represented by a 32-bit integer, then the values returned by
8560 ** sqlite3_status() are undefined.
8561 **
8562 ** See also: [sqlite3_db_status()]
8563 */
8564 SQLITE_API int sqlite3_status(int op, int *pCurrent, int *pHighwater, int resetFlag);
8565 SQLITE_API int sqlite3_status64(
8566 int op,
8567 sqlite3_int64 *pCurrent,
8568 sqlite3_int64 *pHighwater,
8569 int resetFlag
8570 );
8571
8572
8573 /*
8574 ** CAPI3REF: Status Parameters
8575 ** KEYWORDS: {status parameters}
8576 **
8577 ** These integer constants designate various run-time status parameters
8578 ** that can be returned by [sqlite3_status()].
8579 **
8580 ** <dl>
8581 ** [[SQLITE_STATUS_MEMORY_USED]] ^(<dt>SQLITE_STATUS_MEMORY_USED</dt>
8582 ** <dd>This parameter is the current amount of memory checked out
8583 ** using [sqlite3_malloc()], either directly or indirectly. The
8584 ** figure includes calls made to [sqlite3_malloc()] by the application
8585 ** and internal memory usage by the SQLite library. Auxiliary page-cache
8586 ** memory controlled by [SQLITE_CONFIG_PAGECACHE] is not included in
8587 ** this parameter. The amount returned is the sum of the allocation
8588 ** sizes as reported by the xSize method in [sqlite3_mem_methods].</dd>)^
8589 **
8590 ** [[SQLITE_STATUS_MALLOC_SIZE]] ^(<dt>SQLITE_STATUS_MALLOC_SIZE</dt>
8591 ** <dd>This parameter records the largest memory allocation request
8592 ** handed to [sqlite3_malloc()] or [sqlite3_realloc()] (or their
8593 ** internal equivalents). Only the value returned in the
8594 ** *pHighwater parameter to [sqlite3_status()] is of interest.
8595 ** The value written into the *pCurrent parameter is undefined.</dd>)^
8596 **
8597 ** [[SQLITE_STATUS_MALLOC_COUNT]] ^(<dt>SQLITE_STATUS_MALLOC_COUNT</dt>
8598 ** <dd>This parameter records the number of separate memory allocations
8599 ** currently checked out.</dd>)^
8600 **
8601 ** [[SQLITE_STATUS_PAGECACHE_USED]] ^(<dt>SQLITE_STATUS_PAGECACHE_USED</dt>
8602 ** <dd>This parameter returns the number of pages used out of the
8603 ** [pagecache memory allocator] that was configured using
8604 ** [SQLITE_CONFIG_PAGECACHE]. The
8605 ** value returned is in pages, not in bytes.</dd>)^
8606 **
8607 ** [[SQLITE_STATUS_PAGECACHE_OVERFLOW]]
8608 ** ^(<dt>SQLITE_STATUS_PAGECACHE_OVERFLOW</dt>
8609 ** <dd>This parameter returns the number of bytes of page cache
8610 ** allocation which could not be satisfied by the [SQLITE_CONFIG_PAGECACHE]
8611 ** buffer and where forced to overflow to [sqlite3_malloc()]. The
8612 ** returned value includes allocations that overflowed because they
8613 ** where too large (they were larger than the "sz" parameter to
8614 ** [SQLITE_CONFIG_PAGECACHE]) and allocations that overflowed because
8615 ** no space was left in the page cache.</dd>)^
8616 **
8617 ** [[SQLITE_STATUS_PAGECACHE_SIZE]] ^(<dt>SQLITE_STATUS_PAGECACHE_SIZE</dt>
8618 ** <dd>This parameter records the largest memory allocation request
8619 ** handed to the [pagecache memory allocator]. Only the value returned in the
8620 ** *pHighwater parameter to [sqlite3_status()] is of interest.
8621 ** The value written into the *pCurrent parameter is undefined.</dd>)^
8622 **
8623 ** [[SQLITE_STATUS_SCRATCH_USED]] <dt>SQLITE_STATUS_SCRATCH_USED</dt>
8624 ** <dd>No longer used.</dd>
8625 **
8626 ** [[SQLITE_STATUS_SCRATCH_OVERFLOW]] ^(<dt>SQLITE_STATUS_SCRATCH_OVERFLOW</dt>
8627 ** <dd>No longer used.</dd>
8628 **
8629 ** [[SQLITE_STATUS_SCRATCH_SIZE]] <dt>SQLITE_STATUS_SCRATCH_SIZE</dt>
8630 ** <dd>No longer used.</dd>
8631 **
8632 ** [[SQLITE_STATUS_PARSER_STACK]] ^(<dt>SQLITE_STATUS_PARSER_STACK</dt>
8633 ** <dd>The *pHighwater parameter records the deepest parser stack.
8634 ** The *pCurrent value is undefined. The *pHighwater value is only
8635 ** meaningful if SQLite is compiled with [YYTRACKMAXSTACKDEPTH].</dd>)^
8636 ** </dl>
8637 **
8638 ** New status parameters may be added from time to time.
8639 */
8640 #define SQLITE_STATUS_MEMORY_USED 0
8641 #define SQLITE_STATUS_PAGECACHE_USED 1
8642 #define SQLITE_STATUS_PAGECACHE_OVERFLOW 2
8643 #define SQLITE_STATUS_SCRATCH_USED 3 /* NOT USED */
8644 #define SQLITE_STATUS_SCRATCH_OVERFLOW 4 /* NOT USED */
8645 #define SQLITE_STATUS_MALLOC_SIZE 5
8646 #define SQLITE_STATUS_PARSER_STACK 6
8647 #define SQLITE_STATUS_PAGECACHE_SIZE 7
8648 #define SQLITE_STATUS_SCRATCH_SIZE 8 /* NOT USED */
8649 #define SQLITE_STATUS_MALLOC_COUNT 9
8650
8651 /*
8652 ** CAPI3REF: Database Connection Status
8653 ** METHOD: sqlite3
8654 **
8655 ** ^This interface is used to retrieve runtime status information
8656 ** about a single [database connection]. ^The first argument is the
8657 ** database connection object to be interrogated. ^The second argument
8658 ** is an integer constant, taken from the set of
8659 ** [SQLITE_DBSTATUS options], that
8660 ** determines the parameter to interrogate. The set of
8661 ** [SQLITE_DBSTATUS options] is likely
8662 ** to grow in future releases of SQLite.
8663 **
8664 ** ^The current value of the requested parameter is written into *pCur
8665 ** and the highest instantaneous value is written into *pHiwtr. ^If
8666 ** the resetFlg is true, then the highest instantaneous value is
8667 ** reset back down to the current value.
8668 **
8669 ** ^The sqlite3_db_status() routine returns SQLITE_OK on success and a
8670 ** non-zero [error code] on failure.
8671 **
8672 ** See also: [sqlite3_status()] and [sqlite3_stmt_status()].
8673 */
8674 SQLITE_API int sqlite3_db_status(sqlite3*, int op, int *pCur, int *pHiwtr, int resetFlg);
8675
8676 /*
8677 ** CAPI3REF: Status Parameters for database connections
8678 ** KEYWORDS: {SQLITE_DBSTATUS options}
8679 **
8680 ** These constants are the available integer "verbs" that can be passed as
8681 ** the second argument to the [sqlite3_db_status()] interface.
8682 **
8683 ** New verbs may be added in future releases of SQLite. Existing verbs
8684 ** might be discontinued. Applications should check the return code from
8685 ** [sqlite3_db_status()] to make sure that the call worked.
8686 ** The [sqlite3_db_status()] interface will return a non-zero error code
8687 ** if a discontinued or unsupported verb is invoked.
8688 **
8689 ** <dl>
8690 ** [[SQLITE_DBSTATUS_LOOKASIDE_USED]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_USED</dt>
8691 ** <dd>This parameter returns the number of lookaside memory slots currently
8692 ** checked out.</dd>)^
8693 **
8694 ** [[SQLITE_DBSTATUS_LOOKASIDE_HIT]] ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_HIT</dt>
8695 ** <dd>This parameter returns the number of malloc attempts that were
8696 ** satisfied using lookaside memory. Only the high-water value is meaningful;
8697 ** the current value is always zero.)^
8698 **
8699 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE]]
8700 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE</dt>
8701 ** <dd>This parameter returns the number malloc attempts that might have
8702 ** been satisfied using lookaside memory but failed due to the amount of
8703 ** memory requested being larger than the lookaside slot size.
8704 ** Only the high-water value is meaningful;
8705 ** the current value is always zero.)^
8706 **
8707 ** [[SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL]]
8708 ** ^(<dt>SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL</dt>
8709 ** <dd>This parameter returns the number malloc attempts that might have
8710 ** been satisfied using lookaside memory but failed due to all lookaside
8711 ** memory already being in use.
8712 ** Only the high-water value is meaningful;
8713 ** the current value is always zero.)^
8714 **
8715 ** [[SQLITE_DBSTATUS_CACHE_USED]] ^(<dt>SQLITE_DBSTATUS_CACHE_USED</dt>
8716 ** <dd>This parameter returns the approximate number of bytes of heap
8717 ** memory used by all pager caches associated with the database connection.)^
8718 ** ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_USED is always 0.
8719 **
8720 ** [[SQLITE_DBSTATUS_CACHE_USED_SHARED]]
8721 ** ^(<dt>SQLITE_DBSTATUS_CACHE_USED_SHARED</dt>
8722 ** <dd>This parameter is similar to DBSTATUS_CACHE_USED, except that if a
8723 ** pager cache is shared between two or more connections the bytes of heap
8724 ** memory used by that pager cache is divided evenly between the attached
8725 ** connections.)^ In other words, if none of the pager caches associated
8726 ** with the database connection are shared, this request returns the same
8727 ** value as DBSTATUS_CACHE_USED. Or, if one or more or the pager caches are
8728 ** shared, the value returned by this call will be smaller than that returned
8729 ** by DBSTATUS_CACHE_USED. ^The highwater mark associated with
8730 ** SQLITE_DBSTATUS_CACHE_USED_SHARED is always 0.
8731 **
8732 ** [[SQLITE_DBSTATUS_SCHEMA_USED]] ^(<dt>SQLITE_DBSTATUS_SCHEMA_USED</dt>
8733 ** <dd>This parameter returns the approximate number of bytes of heap
8734 ** memory used to store the schema for all databases associated
8735 ** with the connection - main, temp, and any [ATTACH]-ed databases.)^
8736 ** ^The full amount of memory used by the schemas is reported, even if the
8737 ** schema memory is shared with other database connections due to
8738 ** [shared cache mode] being enabled.
8739 ** ^The highwater mark associated with SQLITE_DBSTATUS_SCHEMA_USED is always 0.
8740 **
8741 ** [[SQLITE_DBSTATUS_STMT_USED]] ^(<dt>SQLITE_DBSTATUS_STMT_USED</dt>
8742 ** <dd>This parameter returns the approximate number of bytes of heap
8743 ** and lookaside memory used by all prepared statements associated with
8744 ** the database connection.)^
8745 ** ^The highwater mark associated with SQLITE_DBSTATUS_STMT_USED is always 0.
8746 ** </dd>
8747 **
8748 ** [[SQLITE_DBSTATUS_CACHE_HIT]] ^(<dt>SQLITE_DBSTATUS_CACHE_HIT</dt>
8749 ** <dd>This parameter returns the number of pager cache hits that have
8750 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_HIT
8751 ** is always 0.
8752 ** </dd>
8753 **
8754 ** [[SQLITE_DBSTATUS_CACHE_MISS]] ^(<dt>SQLITE_DBSTATUS_CACHE_MISS</dt>
8755 ** <dd>This parameter returns the number of pager cache misses that have
8756 ** occurred.)^ ^The highwater mark associated with SQLITE_DBSTATUS_CACHE_MISS
8757 ** is always 0.
8758 ** </dd>
8759 **
8760 ** [[SQLITE_DBSTATUS_CACHE_WRITE]] ^(<dt>SQLITE_DBSTATUS_CACHE_WRITE</dt>
8761 ** <dd>This parameter returns the number of dirty cache entries that have
8762 ** been written to disk. Specifically, the number of pages written to the
8763 ** wal file in wal mode databases, or the number of pages written to the
8764 ** database file in rollback mode databases. Any pages written as part of
8765 ** transaction rollback or database recovery operations are not included.
8766 ** If an IO or other error occurs while writing a page to disk, the effect
8767 ** on subsequent SQLITE_DBSTATUS_CACHE_WRITE requests is undefined.)^ ^The
8768 ** highwater mark associated with SQLITE_DBSTATUS_CACHE_WRITE is always 0.
8769 ** </dd>
8770 **
8771 ** [[SQLITE_DBSTATUS_CACHE_SPILL]] ^(<dt>SQLITE_DBSTATUS_CACHE_SPILL</dt>
8772 ** <dd>This parameter returns the number of dirty cache entries that have
8773 ** been written to disk in the middle of a transaction due to the page
8774 ** cache overflowing. Transactions are more efficient if they are written
8775 ** to disk all at once. When pages spill mid-transaction, that introduces
8776 ** additional overhead. This parameter can be used help identify
8777 ** inefficiencies that can be resolved by increasing the cache size.
8778 ** </dd>
8779 **
8780 ** [[SQLITE_DBSTATUS_DEFERRED_FKS]] ^(<dt>SQLITE_DBSTATUS_DEFERRED_FKS</dt>
8781 ** <dd>This parameter returns zero for the current value if and only if
8782 ** all foreign key constraints (deferred or immediate) have been
8783 ** resolved.)^ ^The highwater mark is always 0.
8784 ** </dd>
8785 ** </dl>
8786 */
8787 #define SQLITE_DBSTATUS_LOOKASIDE_USED 0
8788 #define SQLITE_DBSTATUS_CACHE_USED 1
8789 #define SQLITE_DBSTATUS_SCHEMA_USED 2
8790 #define SQLITE_DBSTATUS_STMT_USED 3
8791 #define SQLITE_DBSTATUS_LOOKASIDE_HIT 4
8792 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_SIZE 5
8793 #define SQLITE_DBSTATUS_LOOKASIDE_MISS_FULL 6
8794 #define SQLITE_DBSTATUS_CACHE_HIT 7
8795 #define SQLITE_DBSTATUS_CACHE_MISS 8
8796 #define SQLITE_DBSTATUS_CACHE_WRITE 9
8797 #define SQLITE_DBSTATUS_DEFERRED_FKS 10
8798 #define SQLITE_DBSTATUS_CACHE_USED_SHARED 11
8799 #define SQLITE_DBSTATUS_CACHE_SPILL 12
8800 #define SQLITE_DBSTATUS_MAX 12 /* Largest defined DBSTATUS */
8801
8802
8803 /*
8804 ** CAPI3REF: Prepared Statement Status
8805 ** METHOD: sqlite3_stmt
8806 **
8807 ** ^(Each prepared statement maintains various
8808 ** [SQLITE_STMTSTATUS counters] that measure the number
8809 ** of times it has performed specific operations.)^ These counters can
8810 ** be used to monitor the performance characteristics of the prepared
8811 ** statements. For example, if the number of table steps greatly exceeds
8812 ** the number of table searches or result rows, that would tend to indicate
8813 ** that the prepared statement is using a full table scan rather than
8814 ** an index.
8815 **
8816 ** ^(This interface is used to retrieve and reset counter values from
8817 ** a [prepared statement]. The first argument is the prepared statement
8818 ** object to be interrogated. The second argument
8819 ** is an integer code for a specific [SQLITE_STMTSTATUS counter]
8820 ** to be interrogated.)^
8821 ** ^The current value of the requested counter is returned.
8822 ** ^If the resetFlg is true, then the counter is reset to zero after this
8823 ** interface call returns.
8824 **
8825 ** See also: [sqlite3_status()] and [sqlite3_db_status()].
8826 */
8827 SQLITE_API int sqlite3_stmt_status(sqlite3_stmt*, int op,int resetFlg);
8828
8829 /*
8830 ** CAPI3REF: Status Parameters for prepared statements
8831 ** KEYWORDS: {SQLITE_STMTSTATUS counter} {SQLITE_STMTSTATUS counters}
8832 **
8833 ** These preprocessor macros define integer codes that name counter
8834 ** values associated with the [sqlite3_stmt_status()] interface.
8835 ** The meanings of the various counters are as follows:
8836 **
8837 ** <dl>
8838 ** [[SQLITE_STMTSTATUS_FULLSCAN_STEP]] <dt>SQLITE_STMTSTATUS_FULLSCAN_STEP</dt>
8839 ** <dd>^This is the number of times that SQLite has stepped forward in
8840 ** a table as part of a full table scan. Large numbers for this counter
8841 ** may indicate opportunities for performance improvement through
8842 ** careful use of indices.</dd>
8843 **
8844 ** [[SQLITE_STMTSTATUS_SORT]] <dt>SQLITE_STMTSTATUS_SORT</dt>
8845 ** <dd>^This is the number of sort operations that have occurred.
8846 ** A non-zero value in this counter may indicate an opportunity to
8847 ** improvement performance through careful use of indices.</dd>
8848 **
8849 ** [[SQLITE_STMTSTATUS_AUTOINDEX]] <dt>SQLITE_STMTSTATUS_AUTOINDEX</dt>
8850 ** <dd>^This is the number of rows inserted into transient indices that
8851 ** were created automatically in order to help joins run faster.
8852 ** A non-zero value in this counter may indicate an opportunity to
8853 ** improvement performance by adding permanent indices that do not
8854 ** need to be reinitialized each time the statement is run.</dd>
8855 **
8856 ** [[SQLITE_STMTSTATUS_VM_STEP]] <dt>SQLITE_STMTSTATUS_VM_STEP</dt>
8857 ** <dd>^This is the number of virtual machine operations executed
8858 ** by the prepared statement if that number is less than or equal
8859 ** to 2147483647. The number of virtual machine operations can be
8860 ** used as a proxy for the total work done by the prepared statement.
8861 ** If the number of virtual machine operations exceeds 2147483647
8862 ** then the value returned by this statement status code is undefined.
8863 **
8864 ** [[SQLITE_STMTSTATUS_REPREPARE]] <dt>SQLITE_STMTSTATUS_REPREPARE</dt>
8865 ** <dd>^This is the number of times that the prepare statement has been
8866 ** automatically regenerated due to schema changes or changes to
8867 ** [bound parameters] that might affect the query plan.
8868 **
8869 ** [[SQLITE_STMTSTATUS_RUN]] <dt>SQLITE_STMTSTATUS_RUN</dt>
8870 ** <dd>^This is the number of times that the prepared statement has
8871 ** been run. A single "run" for the purposes of this counter is one
8872 ** or more calls to [sqlite3_step()] followed by a call to [sqlite3_reset()].
8873 ** The counter is incremented on the first [sqlite3_step()] call of each
8874 ** cycle.
8875 **
8876 ** [[SQLITE_STMTSTATUS_FILTER_MISS]]
8877 ** [[SQLITE_STMTSTATUS_FILTER HIT]]
8878 ** <dt>SQLITE_STMTSTATUS_FILTER_HIT<br>
8879 ** SQLITE_STMTSTATUS_FILTER_MISS</dt>
8880 ** <dd>^SQLITE_STMTSTATUS_FILTER_HIT is the number of times that a join
8881 ** step was bypassed because a Bloom filter returned not-found. The
8882 ** corresponding SQLITE_STMTSTATUS_FILTER_MISS value is the number of
8883 ** times that the Bloom filter returned a find, and thus the join step
8884 ** had to be processed as normal.
8885 **
8886 ** [[SQLITE_STMTSTATUS_MEMUSED]] <dt>SQLITE_STMTSTATUS_MEMUSED</dt>
8887 ** <dd>^This is the approximate number of bytes of heap memory
8888 ** used to store the prepared statement. ^This value is not actually
8889 ** a counter, and so the resetFlg parameter to sqlite3_stmt_status()
8890 ** is ignored when the opcode is SQLITE_STMTSTATUS_MEMUSED.
8891 ** </dd>
8892 ** </dl>
8893 */
8894 #define SQLITE_STMTSTATUS_FULLSCAN_STEP 1
8895 #define SQLITE_STMTSTATUS_SORT 2
8896 #define SQLITE_STMTSTATUS_AUTOINDEX 3
8897 #define SQLITE_STMTSTATUS_VM_STEP 4
8898 #define SQLITE_STMTSTATUS_REPREPARE 5
8899 #define SQLITE_STMTSTATUS_RUN 6
8900 #define SQLITE_STMTSTATUS_FILTER_MISS 7
8901 #define SQLITE_STMTSTATUS_FILTER_HIT 8
8902 #define SQLITE_STMTSTATUS_MEMUSED 99
8903
8904 /*
8905 ** CAPI3REF: Custom Page Cache Object
8906 **
8907 ** The sqlite3_pcache type is opaque. It is implemented by
8908 ** the pluggable module. The SQLite core has no knowledge of
8909 ** its size or internal structure and never deals with the
8910 ** sqlite3_pcache object except by holding and passing pointers
8911 ** to the object.
8912 **
8913 ** See [sqlite3_pcache_methods2] for additional information.
8914 */
8915 typedef struct sqlite3_pcache sqlite3_pcache;
8916
8917 /*
8918 ** CAPI3REF: Custom Page Cache Object
8919 **
8920 ** The sqlite3_pcache_page object represents a single page in the
8921 ** page cache. The page cache will allocate instances of this
8922 ** object. Various methods of the page cache use pointers to instances
8923 ** of this object as parameters or as their return value.
8924 **
8925 ** See [sqlite3_pcache_methods2] for additional information.
8926 */
8927 typedef struct sqlite3_pcache_page sqlite3_pcache_page;
8928 struct sqlite3_pcache_page {
8929 void *pBuf; /* The content of the page */
8930 void *pExtra; /* Extra information associated with the page */
8931 };
8932
8933 /*
8934 ** CAPI3REF: Application Defined Page Cache.
8935 ** KEYWORDS: {page cache}
8936 **
8937 ** ^(The [sqlite3_config]([SQLITE_CONFIG_PCACHE2], ...) interface can
8938 ** register an alternative page cache implementation by passing in an
8939 ** instance of the sqlite3_pcache_methods2 structure.)^
8940 ** In many applications, most of the heap memory allocated by
8941 ** SQLite is used for the page cache.
8942 ** By implementing a
8943 ** custom page cache using this API, an application can better control
8944 ** the amount of memory consumed by SQLite, the way in which
8945 ** that memory is allocated and released, and the policies used to
8946 ** determine exactly which parts of a database file are cached and for
8947 ** how long.
8948 **
8949 ** The alternative page cache mechanism is an
8950 ** extreme measure that is only needed by the most demanding applications.
8951 ** The built-in page cache is recommended for most uses.
8952 **
8953 ** ^(The contents of the sqlite3_pcache_methods2 structure are copied to an
8954 ** internal buffer by SQLite within the call to [sqlite3_config]. Hence
8955 ** the application may discard the parameter after the call to
8956 ** [sqlite3_config()] returns.)^
8957 **
8958 ** [[the xInit() page cache method]]
8959 ** ^(The xInit() method is called once for each effective
8960 ** call to [sqlite3_initialize()])^
8961 ** (usually only once during the lifetime of the process). ^(The xInit()
8962 ** method is passed a copy of the sqlite3_pcache_methods2.pArg value.)^
8963 ** The intent of the xInit() method is to set up global data structures
8964 ** required by the custom page cache implementation.
8965 ** ^(If the xInit() method is NULL, then the
8966 ** built-in default page cache is used instead of the application defined
8967 ** page cache.)^
8968 **
8969 ** [[the xShutdown() page cache method]]
8970 ** ^The xShutdown() method is called by [sqlite3_shutdown()].
8971 ** It can be used to clean up
8972 ** any outstanding resources before process shutdown, if required.
8973 ** ^The xShutdown() method may be NULL.
8974 **
8975 ** ^SQLite automatically serializes calls to the xInit method,
8976 ** so the xInit method need not be threadsafe. ^The
8977 ** xShutdown method is only called from [sqlite3_shutdown()] so it does
8978 ** not need to be threadsafe either. All other methods must be threadsafe
8979 ** in multithreaded applications.
8980 **
8981 ** ^SQLite will never invoke xInit() more than once without an intervening
8982 ** call to xShutdown().
8983 **
8984 ** [[the xCreate() page cache methods]]
8985 ** ^SQLite invokes the xCreate() method to construct a new cache instance.
8986 ** SQLite will typically create one cache instance for each open database file,
8987 ** though this is not guaranteed. ^The
8988 ** first parameter, szPage, is the size in bytes of the pages that must
8989 ** be allocated by the cache. ^szPage will always a power of two. ^The
8990 ** second parameter szExtra is a number of bytes of extra storage
8991 ** associated with each page cache entry. ^The szExtra parameter will
8992 ** a number less than 250. SQLite will use the
8993 ** extra szExtra bytes on each page to store metadata about the underlying
8994 ** database page on disk. The value passed into szExtra depends
8995 ** on the SQLite version, the target platform, and how SQLite was compiled.
8996 ** ^The third argument to xCreate(), bPurgeable, is true if the cache being
8997 ** created will be used to cache database pages of a file stored on disk, or
8998 ** false if it is used for an in-memory database. The cache implementation
8999 ** does not have to do anything special based with the value of bPurgeable;
9000 ** it is purely advisory. ^On a cache where bPurgeable is false, SQLite will
9001 ** never invoke xUnpin() except to deliberately delete a page.
9002 ** ^In other words, calls to xUnpin() on a cache with bPurgeable set to
9003 ** false will always have the "discard" flag set to true.
9004 ** ^Hence, a cache created with bPurgeable false will
9005 ** never contain any unpinned pages.
9006 **
9007 ** [[the xCachesize() page cache method]]
9008 ** ^(The xCachesize() method may be called at any time by SQLite to set the
9009 ** suggested maximum cache-size (number of pages stored by) the cache
9010 ** instance passed as the first argument. This is the value configured using
9011 ** the SQLite "[PRAGMA cache_size]" command.)^ As with the bPurgeable
9012 ** parameter, the implementation is not required to do anything with this
9013 ** value; it is advisory only.
9014 **
9015 ** [[the xPagecount() page cache methods]]
9016 ** The xPagecount() method must return the number of pages currently
9017 ** stored in the cache, both pinned and unpinned.
9018 **
9019 ** [[the xFetch() page cache methods]]
9020 ** The xFetch() method locates a page in the cache and returns a pointer to
9021 ** an sqlite3_pcache_page object associated with that page, or a NULL pointer.
9022 ** The pBuf element of the returned sqlite3_pcache_page object will be a
9023 ** pointer to a buffer of szPage bytes used to store the content of a
9024 ** single database page. The pExtra element of sqlite3_pcache_page will be
9025 ** a pointer to the szExtra bytes of extra storage that SQLite has requested
9026 ** for each entry in the page cache.
9027 **
9028 ** The page to be fetched is determined by the key. ^The minimum key value
9029 ** is 1. After it has been retrieved using xFetch, the page is considered
9030 ** to be "pinned".
9031 **
9032 ** If the requested page is already in the page cache, then the page cache
9033 ** implementation must return a pointer to the page buffer with its content
9034 ** intact. If the requested page is not already in the cache, then the
9035 ** cache implementation should use the value of the createFlag
9036 ** parameter to help it determined what action to take:
9037 **
9038 ** <table border=1 width=85% align=center>
9039 ** <tr><th> createFlag <th> Behavior when page is not already in cache
9040 ** <tr><td> 0 <td> Do not allocate a new page. Return NULL.
9041 ** <tr><td> 1 <td> Allocate a new page if it easy and convenient to do so.
9042 ** Otherwise return NULL.
9043 ** <tr><td> 2 <td> Make every effort to allocate a new page. Only return
9044 ** NULL if allocating a new page is effectively impossible.
9045 ** </table>
9046 **
9047 ** ^(SQLite will normally invoke xFetch() with a createFlag of 0 or 1. SQLite
9048 ** will only use a createFlag of 2 after a prior call with a createFlag of 1
9049 ** failed.)^ In between the xFetch() calls, SQLite may
9050 ** attempt to unpin one or more cache pages by spilling the content of
9051 ** pinned pages to disk and synching the operating system disk cache.
9052 **
9053 ** [[the xUnpin() page cache method]]
9054 ** ^xUnpin() is called by SQLite with a pointer to a currently pinned page
9055 ** as its second argument. If the third parameter, discard, is non-zero,
9056 ** then the page must be evicted from the cache.
9057 ** ^If the discard parameter is
9058 ** zero, then the page may be discarded or retained at the discretion of
9059 ** page cache implementation. ^The page cache implementation
9060 ** may choose to evict unpinned pages at any time.
9061 **
9062 ** The cache must not perform any reference counting. A single
9063 ** call to xUnpin() unpins the page regardless of the number of prior calls
9064 ** to xFetch().
9065 **
9066 ** [[the xRekey() page cache methods]]
9067 ** The xRekey() method is used to change the key value associated with the
9068 ** page passed as the second argument. If the cache
9069 ** previously contains an entry associated with newKey, it must be
9070 ** discarded. ^Any prior cache entry associated with newKey is guaranteed not
9071 ** to be pinned.
9072 **
9073 ** When SQLite calls the xTruncate() method, the cache must discard all
9074 ** existing cache entries with page numbers (keys) greater than or equal
9075 ** to the value of the iLimit parameter passed to xTruncate(). If any
9076 ** of these pages are pinned, they are implicitly unpinned, meaning that
9077 ** they can be safely discarded.
9078 **
9079 ** [[the xDestroy() page cache method]]
9080 ** ^The xDestroy() method is used to delete a cache allocated by xCreate().
9081 ** All resources associated with the specified cache should be freed. ^After
9082 ** calling the xDestroy() method, SQLite considers the [sqlite3_pcache*]
9083 ** handle invalid, and will not use it with any other sqlite3_pcache_methods2
9084 ** functions.
9085 **
9086 ** [[the xShrink() page cache method]]
9087 ** ^SQLite invokes the xShrink() method when it wants the page cache to
9088 ** free up as much of heap memory as possible. The page cache implementation
9089 ** is not obligated to free any memory, but well-behaved implementations should
9090 ** do their best.
9091 */
9092 typedef struct sqlite3_pcache_methods2 sqlite3_pcache_methods2;
9093 struct sqlite3_pcache_methods2 {
9094 int iVersion;
9095 void *pArg;
9096 int (*xInit)(void*);
9097 void (*xShutdown)(void*);
9098 sqlite3_pcache *(*xCreate)(int szPage, int szExtra, int bPurgeable);
9099 void (*xCachesize)(sqlite3_pcache*, int nCachesize);
9100 int (*xPagecount)(sqlite3_pcache*);
9101 sqlite3_pcache_page *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
9102 void (*xUnpin)(sqlite3_pcache*, sqlite3_pcache_page*, int discard);
9103 void (*xRekey)(sqlite3_pcache*, sqlite3_pcache_page*,
9104 unsigned oldKey, unsigned newKey);
9105 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
9106 void (*xDestroy)(sqlite3_pcache*);
9107 void (*xShrink)(sqlite3_pcache*);
9108 };
9109
9110 /*
9111 ** This is the obsolete pcache_methods object that has now been replaced
9112 ** by sqlite3_pcache_methods2. This object is not used by SQLite. It is
9113 ** retained in the header file for backwards compatibility only.
9114 */
9115 typedef struct sqlite3_pcache_methods sqlite3_pcache_methods;
9116 struct sqlite3_pcache_methods {
9117 void *pArg;
9118 int (*xInit)(void*);
9119 void (*xShutdown)(void*);
9120 sqlite3_pcache *(*xCreate)(int szPage, int bPurgeable);
9121 void (*xCachesize)(sqlite3_pcache*, int nCachesize);
9122 int (*xPagecount)(sqlite3_pcache*);
9123 void *(*xFetch)(sqlite3_pcache*, unsigned key, int createFlag);
9124 void (*xUnpin)(sqlite3_pcache*, void*, int discard);
9125 void (*xRekey)(sqlite3_pcache*, void*, unsigned oldKey, unsigned newKey);
9126 void (*xTruncate)(sqlite3_pcache*, unsigned iLimit);
9127 void (*xDestroy)(sqlite3_pcache*);
9128 };
9129
9130
9131 /*
9132 ** CAPI3REF: Online Backup Object
9133 **
9134 ** The sqlite3_backup object records state information about an ongoing
9135 ** online backup operation. ^The sqlite3_backup object is created by
9136 ** a call to [sqlite3_backup_init()] and is destroyed by a call to
9137 ** [sqlite3_backup_finish()].
9138 **
9139 ** See Also: [Using the SQLite Online Backup API]
9140 */
9141 typedef struct sqlite3_backup sqlite3_backup;
9142
9143 /*
9144 ** CAPI3REF: Online Backup API.
9145 **
9146 ** The backup API copies the content of one database into another.
9147 ** It is useful either for creating backups of databases or
9148 ** for copying in-memory databases to or from persistent files.
9149 **
9150 ** See Also: [Using the SQLite Online Backup API]
9151 **
9152 ** ^SQLite holds a write transaction open on the destination database file
9153 ** for the duration of the backup operation.
9154 ** ^The source database is read-locked only while it is being read;
9155 ** it is not locked continuously for the entire backup operation.
9156 ** ^Thus, the backup may be performed on a live source database without
9157 ** preventing other database connections from
9158 ** reading or writing to the source database while the backup is underway.
9159 **
9160 ** ^(To perform a backup operation:
9161 ** <ol>
9162 ** <li><b>sqlite3_backup_init()</b> is called once to initialize the
9163 ** backup,
9164 ** <li><b>sqlite3_backup_step()</b> is called one or more times to transfer
9165 ** the data between the two databases, and finally
9166 ** <li><b>sqlite3_backup_finish()</b> is called to release all resources
9167 ** associated with the backup operation.
9168 ** </ol>)^
9169 ** There should be exactly one call to sqlite3_backup_finish() for each
9170 ** successful call to sqlite3_backup_init().
9171 **
9172 ** [[sqlite3_backup_init()]] <b>sqlite3_backup_init()</b>
9173 **
9174 ** ^The D and N arguments to sqlite3_backup_init(D,N,S,M) are the
9175 ** [database connection] associated with the destination database
9176 ** and the database name, respectively.
9177 ** ^The database name is "main" for the main database, "temp" for the
9178 ** temporary database, or the name specified after the AS keyword in
9179 ** an [ATTACH] statement for an attached database.
9180 ** ^The S and M arguments passed to
9181 ** sqlite3_backup_init(D,N,S,M) identify the [database connection]
9182 ** and database name of the source database, respectively.
9183 ** ^The source and destination [database connections] (parameters S and D)
9184 ** must be different or else sqlite3_backup_init(D,N,S,M) will fail with
9185 ** an error.
9186 **
9187 ** ^A call to sqlite3_backup_init() will fail, returning NULL, if
9188 ** there is already a read or read-write transaction open on the
9189 ** destination database.
9190 **
9191 ** ^If an error occurs within sqlite3_backup_init(D,N,S,M), then NULL is
9192 ** returned and an error code and error message are stored in the
9193 ** destination [database connection] D.
9194 ** ^The error code and message for the failed call to sqlite3_backup_init()
9195 ** can be retrieved using the [sqlite3_errcode()], [sqlite3_errmsg()], and/or
9196 ** [sqlite3_errmsg16()] functions.
9197 ** ^A successful call to sqlite3_backup_init() returns a pointer to an
9198 ** [sqlite3_backup] object.
9199 ** ^The [sqlite3_backup] object may be used with the sqlite3_backup_step() and
9200 ** sqlite3_backup_finish() functions to perform the specified backup
9201 ** operation.
9202 **
9203 ** [[sqlite3_backup_step()]] <b>sqlite3_backup_step()</b>
9204 **
9205 ** ^Function sqlite3_backup_step(B,N) will copy up to N pages between
9206 ** the source and destination databases specified by [sqlite3_backup] object B.
9207 ** ^If N is negative, all remaining source pages are copied.
9208 ** ^If sqlite3_backup_step(B,N) successfully copies N pages and there
9209 ** are still more pages to be copied, then the function returns [SQLITE_OK].
9210 ** ^If sqlite3_backup_step(B,N) successfully finishes copying all pages
9211 ** from source to destination, then it returns [SQLITE_DONE].
9212 ** ^If an error occurs while running sqlite3_backup_step(B,N),
9213 ** then an [error code] is returned. ^As well as [SQLITE_OK] and
9214 ** [SQLITE_DONE], a call to sqlite3_backup_step() may return [SQLITE_READONLY],
9215 ** [SQLITE_NOMEM], [SQLITE_BUSY], [SQLITE_LOCKED], or an
9216 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX] extended error code.
9217 **
9218 ** ^(The sqlite3_backup_step() might return [SQLITE_READONLY] if
9219 ** <ol>
9220 ** <li> the destination database was opened read-only, or
9221 ** <li> the destination database is using write-ahead-log journaling
9222 ** and the destination and source page sizes differ, or
9223 ** <li> the destination database is an in-memory database and the
9224 ** destination and source page sizes differ.
9225 ** </ol>)^
9226 **
9227 ** ^If sqlite3_backup_step() cannot obtain a required file-system lock, then
9228 ** the [sqlite3_busy_handler | busy-handler function]
9229 ** is invoked (if one is specified). ^If the
9230 ** busy-handler returns non-zero before the lock is available, then
9231 ** [SQLITE_BUSY] is returned to the caller. ^In this case the call to
9232 ** sqlite3_backup_step() can be retried later. ^If the source
9233 ** [database connection]
9234 ** is being used to write to the source database when sqlite3_backup_step()
9235 ** is called, then [SQLITE_LOCKED] is returned immediately. ^Again, in this
9236 ** case the call to sqlite3_backup_step() can be retried later on. ^(If
9237 ** [SQLITE_IOERR_ACCESS | SQLITE_IOERR_XXX], [SQLITE_NOMEM], or
9238 ** [SQLITE_READONLY] is returned, then
9239 ** there is no point in retrying the call to sqlite3_backup_step(). These
9240 ** errors are considered fatal.)^ The application must accept
9241 ** that the backup operation has failed and pass the backup operation handle
9242 ** to the sqlite3_backup_finish() to release associated resources.
9243 **
9244 ** ^The first call to sqlite3_backup_step() obtains an exclusive lock
9245 ** on the destination file. ^The exclusive lock is not released until either
9246 ** sqlite3_backup_finish() is called or the backup operation is complete
9247 ** and sqlite3_backup_step() returns [SQLITE_DONE]. ^Every call to
9248 ** sqlite3_backup_step() obtains a [shared lock] on the source database that
9249 ** lasts for the duration of the sqlite3_backup_step() call.
9250 ** ^Because the source database is not locked between calls to
9251 ** sqlite3_backup_step(), the source database may be modified mid-way
9252 ** through the backup process. ^If the source database is modified by an
9253 ** external process or via a database connection other than the one being
9254 ** used by the backup operation, then the backup will be automatically
9255 ** restarted by the next call to sqlite3_backup_step(). ^If the source
9256 ** database is modified by the using the same database connection as is used
9257 ** by the backup operation, then the backup database is automatically
9258 ** updated at the same time.
9259 **
9260 ** [[sqlite3_backup_finish()]] <b>sqlite3_backup_finish()</b>
9261 **
9262 ** When sqlite3_backup_step() has returned [SQLITE_DONE], or when the
9263 ** application wishes to abandon the backup operation, the application
9264 ** should destroy the [sqlite3_backup] by passing it to sqlite3_backup_finish().
9265 ** ^The sqlite3_backup_finish() interfaces releases all
9266 ** resources associated with the [sqlite3_backup] object.
9267 ** ^If sqlite3_backup_step() has not yet returned [SQLITE_DONE], then any
9268 ** active write-transaction on the destination database is rolled back.
9269 ** The [sqlite3_backup] object is invalid
9270 ** and may not be used following a call to sqlite3_backup_finish().
9271 **
9272 ** ^The value returned by sqlite3_backup_finish is [SQLITE_OK] if no
9273 ** sqlite3_backup_step() errors occurred, regardless or whether or not
9274 ** sqlite3_backup_step() completed.
9275 ** ^If an out-of-memory condition or IO error occurred during any prior
9276 ** sqlite3_backup_step() call on the same [sqlite3_backup] object, then
9277 ** sqlite3_backup_finish() returns the corresponding [error code].
9278 **
9279 ** ^A return of [SQLITE_BUSY] or [SQLITE_LOCKED] from sqlite3_backup_step()
9280 ** is not a permanent error and does not affect the return value of
9281 ** sqlite3_backup_finish().
9282 **
9283 ** [[sqlite3_backup_remaining()]] [[sqlite3_backup_pagecount()]]
9284 ** <b>sqlite3_backup_remaining() and sqlite3_backup_pagecount()</b>
9285 **
9286 ** ^The sqlite3_backup_remaining() routine returns the number of pages still
9287 ** to be backed up at the conclusion of the most recent sqlite3_backup_step().
9288 ** ^The sqlite3_backup_pagecount() routine returns the total number of pages
9289 ** in the source database at the conclusion of the most recent
9290 ** sqlite3_backup_step().
9291 ** ^(The values returned by these functions are only updated by
9292 ** sqlite3_backup_step(). If the source database is modified in a way that
9293 ** changes the size of the source database or the number of pages remaining,
9294 ** those changes are not reflected in the output of sqlite3_backup_pagecount()
9295 ** and sqlite3_backup_remaining() until after the next
9296 ** sqlite3_backup_step().)^
9297 **
9298 ** <b>Concurrent Usage of Database Handles</b>
9299 **
9300 ** ^The source [database connection] may be used by the application for other
9301 ** purposes while a backup operation is underway or being initialized.
9302 ** ^If SQLite is compiled and configured to support threadsafe database
9303 ** connections, then the source database connection may be used concurrently
9304 ** from within other threads.
9305 **
9306 ** However, the application must guarantee that the destination
9307 ** [database connection] is not passed to any other API (by any thread) after
9308 ** sqlite3_backup_init() is called and before the corresponding call to
9309 ** sqlite3_backup_finish(). SQLite does not currently check to see
9310 ** if the application incorrectly accesses the destination [database connection]
9311 ** and so no error code is reported, but the operations may malfunction
9312 ** nevertheless. Use of the destination database connection while a
9313 ** backup is in progress might also cause a mutex deadlock.
9314 **
9315 ** If running in [shared cache mode], the application must
9316 ** guarantee that the shared cache used by the destination database
9317 ** is not accessed while the backup is running. In practice this means
9318 ** that the application must guarantee that the disk file being
9319 ** backed up to is not accessed by any connection within the process,
9320 ** not just the specific connection that was passed to sqlite3_backup_init().
9321 **
9322 ** The [sqlite3_backup] object itself is partially threadsafe. Multiple
9323 ** threads may safely make multiple concurrent calls to sqlite3_backup_step().
9324 ** However, the sqlite3_backup_remaining() and sqlite3_backup_pagecount()
9325 ** APIs are not strictly speaking threadsafe. If they are invoked at the
9326 ** same time as another thread is invoking sqlite3_backup_step() it is
9327 ** possible that they return invalid values.
9328 */
9329 SQLITE_API sqlite3_backup *sqlite3_backup_init(
9330 sqlite3 *pDest, /* Destination database handle */
9331 const char *zDestName, /* Destination database name */
9332 sqlite3 *pSource, /* Source database handle */
9333 const char *zSourceName /* Source database name */
9334 );
9335 SQLITE_API int sqlite3_backup_step(sqlite3_backup *p, int nPage);
9336 SQLITE_API int sqlite3_backup_finish(sqlite3_backup *p);
9337 SQLITE_API int sqlite3_backup_remaining(sqlite3_backup *p);
9338 SQLITE_API int sqlite3_backup_pagecount(sqlite3_backup *p);
9339
9340 /*
9341 ** CAPI3REF: Unlock Notification
9342 ** METHOD: sqlite3
9343 **
9344 ** ^When running in shared-cache mode, a database operation may fail with
9345 ** an [SQLITE_LOCKED] error if the required locks on the shared-cache or
9346 ** individual tables within the shared-cache cannot be obtained. See
9347 ** [SQLite Shared-Cache Mode] for a description of shared-cache locking.
9348 ** ^This API may be used to register a callback that SQLite will invoke
9349 ** when the connection currently holding the required lock relinquishes it.
9350 ** ^This API is only available if the library was compiled with the
9351 ** [SQLITE_ENABLE_UNLOCK_NOTIFY] C-preprocessor symbol defined.
9352 **
9353 ** See Also: [Using the SQLite Unlock Notification Feature].
9354 **
9355 ** ^Shared-cache locks are released when a database connection concludes
9356 ** its current transaction, either by committing it or rolling it back.
9357 **
9358 ** ^When a connection (known as the blocked connection) fails to obtain a
9359 ** shared-cache lock and SQLITE_LOCKED is returned to the caller, the
9360 ** identity of the database connection (the blocking connection) that
9361 ** has locked the required resource is stored internally. ^After an
9362 ** application receives an SQLITE_LOCKED error, it may call the
9363 ** sqlite3_unlock_notify() method with the blocked connection handle as
9364 ** the first argument to register for a callback that will be invoked
9365 ** when the blocking connections current transaction is concluded. ^The
9366 ** callback is invoked from within the [sqlite3_step] or [sqlite3_close]
9367 ** call that concludes the blocking connection's transaction.
9368 **
9369 ** ^(If sqlite3_unlock_notify() is called in a multi-threaded application,
9370 ** there is a chance that the blocking connection will have already
9371 ** concluded its transaction by the time sqlite3_unlock_notify() is invoked.
9372 ** If this happens, then the specified callback is invoked immediately,
9373 ** from within the call to sqlite3_unlock_notify().)^
9374 **
9375 ** ^If the blocked connection is attempting to obtain a write-lock on a
9376 ** shared-cache table, and more than one other connection currently holds
9377 ** a read-lock on the same table, then SQLite arbitrarily selects one of
9378 ** the other connections to use as the blocking connection.
9379 **
9380 ** ^(There may be at most one unlock-notify callback registered by a
9381 ** blocked connection. If sqlite3_unlock_notify() is called when the
9382 ** blocked connection already has a registered unlock-notify callback,
9383 ** then the new callback replaces the old.)^ ^If sqlite3_unlock_notify() is
9384 ** called with a NULL pointer as its second argument, then any existing
9385 ** unlock-notify callback is canceled. ^The blocked connections
9386 ** unlock-notify callback may also be canceled by closing the blocked
9387 ** connection using [sqlite3_close()].
9388 **
9389 ** The unlock-notify callback is not reentrant. If an application invokes
9390 ** any sqlite3_xxx API functions from within an unlock-notify callback, a
9391 ** crash or deadlock may be the result.
9392 **
9393 ** ^Unless deadlock is detected (see below), sqlite3_unlock_notify() always
9394 ** returns SQLITE_OK.
9395 **
9396 ** <b>Callback Invocation Details</b>
9397 **
9398 ** When an unlock-notify callback is registered, the application provides a
9399 ** single void* pointer that is passed to the callback when it is invoked.
9400 ** However, the signature of the callback function allows SQLite to pass
9401 ** it an array of void* context pointers. The first argument passed to
9402 ** an unlock-notify callback is a pointer to an array of void* pointers,
9403 ** and the second is the number of entries in the array.
9404 **
9405 ** When a blocking connection's transaction is concluded, there may be
9406 ** more than one blocked connection that has registered for an unlock-notify
9407 ** callback. ^If two or more such blocked connections have specified the
9408 ** same callback function, then instead of invoking the callback function
9409 ** multiple times, it is invoked once with the set of void* context pointers
9410 ** specified by the blocked connections bundled together into an array.
9411 ** This gives the application an opportunity to prioritize any actions
9412 ** related to the set of unblocked database connections.
9413 **
9414 ** <b>Deadlock Detection</b>
9415 **
9416 ** Assuming that after registering for an unlock-notify callback a
9417 ** database waits for the callback to be issued before taking any further
9418 ** action (a reasonable assumption), then using this API may cause the
9419 ** application to deadlock. For example, if connection X is waiting for
9420 ** connection Y's transaction to be concluded, and similarly connection
9421 ** Y is waiting on connection X's transaction, then neither connection
9422 ** will proceed and the system may remain deadlocked indefinitely.
9423 **
9424 ** To avoid this scenario, the sqlite3_unlock_notify() performs deadlock
9425 ** detection. ^If a given call to sqlite3_unlock_notify() would put the
9426 ** system in a deadlocked state, then SQLITE_LOCKED is returned and no
9427 ** unlock-notify callback is registered. The system is said to be in
9428 ** a deadlocked state if connection A has registered for an unlock-notify
9429 ** callback on the conclusion of connection B's transaction, and connection
9430 ** B has itself registered for an unlock-notify callback when connection
9431 ** A's transaction is concluded. ^Indirect deadlock is also detected, so
9432 ** the system is also considered to be deadlocked if connection B has
9433 ** registered for an unlock-notify callback on the conclusion of connection
9434 ** C's transaction, where connection C is waiting on connection A. ^Any
9435 ** number of levels of indirection are allowed.
9436 **
9437 ** <b>The "DROP TABLE" Exception</b>
9438 **
9439 ** When a call to [sqlite3_step()] returns SQLITE_LOCKED, it is almost
9440 ** always appropriate to call sqlite3_unlock_notify(). There is however,
9441 ** one exception. When executing a "DROP TABLE" or "DROP INDEX" statement,
9442 ** SQLite checks if there are any currently executing SELECT statements
9443 ** that belong to the same connection. If there are, SQLITE_LOCKED is
9444 ** returned. In this case there is no "blocking connection", so invoking
9445 ** sqlite3_unlock_notify() results in the unlock-notify callback being
9446 ** invoked immediately. If the application then re-attempts the "DROP TABLE"
9447 ** or "DROP INDEX" query, an infinite loop might be the result.
9448 **
9449 ** One way around this problem is to check the extended error code returned
9450 ** by an sqlite3_step() call. ^(If there is a blocking connection, then the
9451 ** extended error code is set to SQLITE_LOCKED_SHAREDCACHE. Otherwise, in
9452 ** the special "DROP TABLE/INDEX" case, the extended error code is just
9453 ** SQLITE_LOCKED.)^
9454 */
9455 SQLITE_API int sqlite3_unlock_notify(
9456 sqlite3 *pBlocked, /* Waiting connection */
9457 void (*xNotify)(void **apArg, int nArg), /* Callback function to invoke */
9458 void *pNotifyArg /* Argument to pass to xNotify */
9459 );
9460
9461
9462 /*
9463 ** CAPI3REF: String Comparison
9464 **
9465 ** ^The [sqlite3_stricmp()] and [sqlite3_strnicmp()] APIs allow applications
9466 ** and extensions to compare the contents of two buffers containing UTF-8
9467 ** strings in a case-independent fashion, using the same definition of "case
9468 ** independence" that SQLite uses internally when comparing identifiers.
9469 */
9470 SQLITE_API int sqlite3_stricmp(const char *, const char *);
9471 SQLITE_API int sqlite3_strnicmp(const char *, const char *, int);
9472
9473 /*
9474 ** CAPI3REF: String Globbing
9475 *
9476 ** ^The [sqlite3_strglob(P,X)] interface returns zero if and only if
9477 ** string X matches the [GLOB] pattern P.
9478 ** ^The definition of [GLOB] pattern matching used in
9479 ** [sqlite3_strglob(P,X)] is the same as for the "X GLOB P" operator in the
9480 ** SQL dialect understood by SQLite. ^The [sqlite3_strglob(P,X)] function
9481 ** is case sensitive.
9482 **
9483 ** Note that this routine returns zero on a match and non-zero if the strings
9484 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
9485 **
9486 ** See also: [sqlite3_strlike()].
9487 */
9488 SQLITE_API int sqlite3_strglob(const char *zGlob, const char *zStr);
9489
9490 /*
9491 ** CAPI3REF: String LIKE Matching
9492 *
9493 ** ^The [sqlite3_strlike(P,X,E)] interface returns zero if and only if
9494 ** string X matches the [LIKE] pattern P with escape character E.
9495 ** ^The definition of [LIKE] pattern matching used in
9496 ** [sqlite3_strlike(P,X,E)] is the same as for the "X LIKE P ESCAPE E"
9497 ** operator in the SQL dialect understood by SQLite. ^For "X LIKE P" without
9498 ** the ESCAPE clause, set the E parameter of [sqlite3_strlike(P,X,E)] to 0.
9499 ** ^As with the LIKE operator, the [sqlite3_strlike(P,X,E)] function is case
9500 ** insensitive - equivalent upper and lower case ASCII characters match
9501 ** one another.
9502 **
9503 ** ^The [sqlite3_strlike(P,X,E)] function matches Unicode characters, though
9504 ** only ASCII characters are case folded.
9505 **
9506 ** Note that this routine returns zero on a match and non-zero if the strings
9507 ** do not match, the same as [sqlite3_stricmp()] and [sqlite3_strnicmp()].
9508 **
9509 ** See also: [sqlite3_strglob()].
9510 */
9511 SQLITE_API int sqlite3_strlike(const char *zGlob, const char *zStr, unsigned int cEsc);
9512
9513 /*
9514 ** CAPI3REF: Error Logging Interface
9515 **
9516 ** ^The [sqlite3_log()] interface writes a message into the [error log]
9517 ** established by the [SQLITE_CONFIG_LOG] option to [sqlite3_config()].
9518 ** ^If logging is enabled, the zFormat string and subsequent arguments are
9519 ** used with [sqlite3_snprintf()] to generate the final output string.
9520 **
9521 ** The sqlite3_log() interface is intended for use by extensions such as
9522 ** virtual tables, collating functions, and SQL functions. While there is
9523 ** nothing to prevent an application from calling sqlite3_log(), doing so
9524 ** is considered bad form.
9525 **
9526 ** The zFormat string must not be NULL.
9527 **
9528 ** To avoid deadlocks and other threading problems, the sqlite3_log() routine
9529 ** will not use dynamically allocated memory. The log message is stored in
9530 ** a fixed-length buffer on the stack. If the log message is longer than
9531 ** a few hundred characters, it will be truncated to the length of the
9532 ** buffer.
9533 */
9534 SQLITE_API void sqlite3_log(int iErrCode, const char *zFormat, ...);
9535
9536 /*
9537 ** CAPI3REF: Write-Ahead Log Commit Hook
9538 ** METHOD: sqlite3
9539 **
9540 ** ^The [sqlite3_wal_hook()] function is used to register a callback that
9541 ** is invoked each time data is committed to a database in wal mode.
9542 **
9543 ** ^(The callback is invoked by SQLite after the commit has taken place and
9544 ** the associated write-lock on the database released)^, so the implementation
9545 ** may read, write or [checkpoint] the database as required.
9546 **
9547 ** ^The first parameter passed to the callback function when it is invoked
9548 ** is a copy of the third parameter passed to sqlite3_wal_hook() when
9549 ** registering the callback. ^The second is a copy of the database handle.
9550 ** ^The third parameter is the name of the database that was written to -
9551 ** either "main" or the name of an [ATTACH]-ed database. ^The fourth parameter
9552 ** is the number of pages currently in the write-ahead log file,
9553 ** including those that were just committed.
9554 **
9555 ** The callback function should normally return [SQLITE_OK]. ^If an error
9556 ** code is returned, that error will propagate back up through the
9557 ** SQLite code base to cause the statement that provoked the callback
9558 ** to report an error, though the commit will have still occurred. If the
9559 ** callback returns [SQLITE_ROW] or [SQLITE_DONE], or if it returns a value
9560 ** that does not correspond to any valid SQLite error code, the results
9561 ** are undefined.
9562 **
9563 ** A single database handle may have at most a single write-ahead log callback
9564 ** registered at one time. ^Calling [sqlite3_wal_hook()] replaces any
9565 ** previously registered write-ahead log callback. ^The return value is
9566 ** a copy of the third parameter from the previous call, if any, or 0.
9567 ** ^Note that the [sqlite3_wal_autocheckpoint()] interface and the
9568 ** [wal_autocheckpoint pragma] both invoke [sqlite3_wal_hook()] and will
9569 ** overwrite any prior [sqlite3_wal_hook()] settings.
9570 */
9571 SQLITE_API void *sqlite3_wal_hook(
9572 sqlite3*,
9573 int(*)(void *,sqlite3*,const char*,int),
9574 void*
9575 );
9576
9577 /*
9578 ** CAPI3REF: Configure an auto-checkpoint
9579 ** METHOD: sqlite3
9580 **
9581 ** ^The [sqlite3_wal_autocheckpoint(D,N)] is a wrapper around
9582 ** [sqlite3_wal_hook()] that causes any database on [database connection] D
9583 ** to automatically [checkpoint]
9584 ** after committing a transaction if there are N or
9585 ** more frames in the [write-ahead log] file. ^Passing zero or
9586 ** a negative value as the nFrame parameter disables automatic
9587 ** checkpoints entirely.
9588 **
9589 ** ^The callback registered by this function replaces any existing callback
9590 ** registered using [sqlite3_wal_hook()]. ^Likewise, registering a callback
9591 ** using [sqlite3_wal_hook()] disables the automatic checkpoint mechanism
9592 ** configured by this function.
9593 **
9594 ** ^The [wal_autocheckpoint pragma] can be used to invoke this interface
9595 ** from SQL.
9596 **
9597 ** ^Checkpoints initiated by this mechanism are
9598 ** [sqlite3_wal_checkpoint_v2|PASSIVE].
9599 **
9600 ** ^Every new [database connection] defaults to having the auto-checkpoint
9601 ** enabled with a threshold of 1000 or [SQLITE_DEFAULT_WAL_AUTOCHECKPOINT]
9602 ** pages. The use of this interface
9603 ** is only necessary if the default setting is found to be suboptimal
9604 ** for a particular application.
9605 */
9606 SQLITE_API int sqlite3_wal_autocheckpoint(sqlite3 *db, int N);
9607
9608 /*
9609 ** CAPI3REF: Checkpoint a database
9610 ** METHOD: sqlite3
9611 **
9612 ** ^(The sqlite3_wal_checkpoint(D,X) is equivalent to
9613 ** [sqlite3_wal_checkpoint_v2](D,X,[SQLITE_CHECKPOINT_PASSIVE],0,0).)^
9614 **
9615 ** In brief, sqlite3_wal_checkpoint(D,X) causes the content in the
9616 ** [write-ahead log] for database X on [database connection] D to be
9617 ** transferred into the database file and for the write-ahead log to
9618 ** be reset. See the [checkpointing] documentation for addition
9619 ** information.
9620 **
9621 ** This interface used to be the only way to cause a checkpoint to
9622 ** occur. But then the newer and more powerful [sqlite3_wal_checkpoint_v2()]
9623 ** interface was added. This interface is retained for backwards
9624 ** compatibility and as a convenience for applications that need to manually
9625 ** start a callback but which do not need the full power (and corresponding
9626 ** complication) of [sqlite3_wal_checkpoint_v2()].
9627 */
9628 SQLITE_API int sqlite3_wal_checkpoint(sqlite3 *db, const char *zDb);
9629
9630 /*
9631 ** CAPI3REF: Checkpoint a database
9632 ** METHOD: sqlite3
9633 **
9634 ** ^(The sqlite3_wal_checkpoint_v2(D,X,M,L,C) interface runs a checkpoint
9635 ** operation on database X of [database connection] D in mode M. Status
9636 ** information is written back into integers pointed to by L and C.)^
9637 ** ^(The M parameter must be a valid [checkpoint mode]:)^
9638 **
9639 ** <dl>
9640 ** <dt>SQLITE_CHECKPOINT_PASSIVE<dd>
9641 ** ^Checkpoint as many frames as possible without waiting for any database
9642 ** readers or writers to finish, then sync the database file if all frames
9643 ** in the log were checkpointed. ^The [busy-handler callback]
9644 ** is never invoked in the SQLITE_CHECKPOINT_PASSIVE mode.
9645 ** ^On the other hand, passive mode might leave the checkpoint unfinished
9646 ** if there are concurrent readers or writers.
9647 **
9648 ** <dt>SQLITE_CHECKPOINT_FULL<dd>
9649 ** ^This mode blocks (it invokes the
9650 ** [sqlite3_busy_handler|busy-handler callback]) until there is no
9651 ** database writer and all readers are reading from the most recent database
9652 ** snapshot. ^It then checkpoints all frames in the log file and syncs the
9653 ** database file. ^This mode blocks new database writers while it is pending,
9654 ** but new database readers are allowed to continue unimpeded.
9655 **
9656 ** <dt>SQLITE_CHECKPOINT_RESTART<dd>
9657 ** ^This mode works the same way as SQLITE_CHECKPOINT_FULL with the addition
9658 ** that after checkpointing the log file it blocks (calls the
9659 ** [busy-handler callback])
9660 ** until all readers are reading from the database file only. ^This ensures
9661 ** that the next writer will restart the log file from the beginning.
9662 ** ^Like SQLITE_CHECKPOINT_FULL, this mode blocks new
9663 ** database writer attempts while it is pending, but does not impede readers.
9664 **
9665 ** <dt>SQLITE_CHECKPOINT_TRUNCATE<dd>
9666 ** ^This mode works the same way as SQLITE_CHECKPOINT_RESTART with the
9667 ** addition that it also truncates the log file to zero bytes just prior
9668 ** to a successful return.
9669 ** </dl>
9670 **
9671 ** ^If pnLog is not NULL, then *pnLog is set to the total number of frames in
9672 ** the log file or to -1 if the checkpoint could not run because
9673 ** of an error or because the database is not in [WAL mode]. ^If pnCkpt is not
9674 ** NULL,then *pnCkpt is set to the total number of checkpointed frames in the
9675 ** log file (including any that were already checkpointed before the function
9676 ** was called) or to -1 if the checkpoint could not run due to an error or
9677 ** because the database is not in WAL mode. ^Note that upon successful
9678 ** completion of an SQLITE_CHECKPOINT_TRUNCATE, the log file will have been
9679 ** truncated to zero bytes and so both *pnLog and *pnCkpt will be set to zero.
9680 **
9681 ** ^All calls obtain an exclusive "checkpoint" lock on the database file. ^If
9682 ** any other process is running a checkpoint operation at the same time, the
9683 ** lock cannot be obtained and SQLITE_BUSY is returned. ^Even if there is a
9684 ** busy-handler configured, it will not be invoked in this case.
9685 **
9686 ** ^The SQLITE_CHECKPOINT_FULL, RESTART and TRUNCATE modes also obtain the
9687 ** exclusive "writer" lock on the database file. ^If the writer lock cannot be
9688 ** obtained immediately, and a busy-handler is configured, it is invoked and
9689 ** the writer lock retried until either the busy-handler returns 0 or the lock
9690 ** is successfully obtained. ^The busy-handler is also invoked while waiting for
9691 ** database readers as described above. ^If the busy-handler returns 0 before
9692 ** the writer lock is obtained or while waiting for database readers, the
9693 ** checkpoint operation proceeds from that point in the same way as
9694 ** SQLITE_CHECKPOINT_PASSIVE - checkpointing as many frames as possible
9695 ** without blocking any further. ^SQLITE_BUSY is returned in this case.
9696 **
9697 ** ^If parameter zDb is NULL or points to a zero length string, then the
9698 ** specified operation is attempted on all WAL databases [attached] to
9699 ** [database connection] db. In this case the
9700 ** values written to output parameters *pnLog and *pnCkpt are undefined. ^If
9701 ** an SQLITE_BUSY error is encountered when processing one or more of the
9702 ** attached WAL databases, the operation is still attempted on any remaining
9703 ** attached databases and SQLITE_BUSY is returned at the end. ^If any other
9704 ** error occurs while processing an attached database, processing is abandoned
9705 ** and the error code is returned to the caller immediately. ^If no error
9706 ** (SQLITE_BUSY or otherwise) is encountered while processing the attached
9707 ** databases, SQLITE_OK is returned.
9708 **
9709 ** ^If database zDb is the name of an attached database that is not in WAL
9710 ** mode, SQLITE_OK is returned and both *pnLog and *pnCkpt set to -1. ^If
9711 ** zDb is not NULL (or a zero length string) and is not the name of any
9712 ** attached database, SQLITE_ERROR is returned to the caller.
9713 **
9714 ** ^Unless it returns SQLITE_MISUSE,
9715 ** the sqlite3_wal_checkpoint_v2() interface
9716 ** sets the error information that is queried by
9717 ** [sqlite3_errcode()] and [sqlite3_errmsg()].
9718 **
9719 ** ^The [PRAGMA wal_checkpoint] command can be used to invoke this interface
9720 ** from SQL.
9721 */
9722 SQLITE_API int sqlite3_wal_checkpoint_v2(
9723 sqlite3 *db, /* Database handle */
9724 const char *zDb, /* Name of attached database (or NULL) */
9725 int eMode, /* SQLITE_CHECKPOINT_* value */
9726 int *pnLog, /* OUT: Size of WAL log in frames */
9727 int *pnCkpt /* OUT: Total number of frames checkpointed */
9728 );
9729
9730 /*
9731 ** CAPI3REF: Checkpoint Mode Values
9732 ** KEYWORDS: {checkpoint mode}
9733 **
9734 ** These constants define all valid values for the "checkpoint mode" passed
9735 ** as the third parameter to the [sqlite3_wal_checkpoint_v2()] interface.
9736 ** See the [sqlite3_wal_checkpoint_v2()] documentation for details on the
9737 ** meaning of each of these checkpoint modes.
9738 */
9739 #define SQLITE_CHECKPOINT_PASSIVE 0 /* Do as much as possible w/o blocking */
9740 #define SQLITE_CHECKPOINT_FULL 1 /* Wait for writers, then checkpoint */
9741 #define SQLITE_CHECKPOINT_RESTART 2 /* Like FULL but wait for readers */
9742 #define SQLITE_CHECKPOINT_TRUNCATE 3 /* Like RESTART but also truncate WAL */
9743
9744 /*
9745 ** CAPI3REF: Virtual Table Interface Configuration
9746 **
9747 ** This function may be called by either the [xConnect] or [xCreate] method
9748 ** of a [virtual table] implementation to configure
9749 ** various facets of the virtual table interface.
9750 **
9751 ** If this interface is invoked outside the context of an xConnect or
9752 ** xCreate virtual table method then the behavior is undefined.
9753 **
9754 ** In the call sqlite3_vtab_config(D,C,...) the D parameter is the
9755 ** [database connection] in which the virtual table is being created and
9756 ** which is passed in as the first argument to the [xConnect] or [xCreate]
9757 ** method that is invoking sqlite3_vtab_config(). The C parameter is one
9758 ** of the [virtual table configuration options]. The presence and meaning
9759 ** of parameters after C depend on which [virtual table configuration option]
9760 ** is used.
9761 */
9762 SQLITE_API int sqlite3_vtab_config(sqlite3*, int op, ...);
9763
9764 /*
9765 ** CAPI3REF: Virtual Table Configuration Options
9766 ** KEYWORDS: {virtual table configuration options}
9767 ** KEYWORDS: {virtual table configuration option}
9768 **
9769 ** These macros define the various options to the
9770 ** [sqlite3_vtab_config()] interface that [virtual table] implementations
9771 ** can use to customize and optimize their behavior.
9772 **
9773 ** <dl>
9774 ** [[SQLITE_VTAB_CONSTRAINT_SUPPORT]]
9775 ** <dt>SQLITE_VTAB_CONSTRAINT_SUPPORT</dt>
9776 ** <dd>Calls of the form
9777 ** [sqlite3_vtab_config](db,SQLITE_VTAB_CONSTRAINT_SUPPORT,X) are supported,
9778 ** where X is an integer. If X is zero, then the [virtual table] whose
9779 ** [xCreate] or [xConnect] method invoked [sqlite3_vtab_config()] does not
9780 ** support constraints. In this configuration (which is the default) if
9781 ** a call to the [xUpdate] method returns [SQLITE_CONSTRAINT], then the entire
9782 ** statement is rolled back as if [ON CONFLICT | OR ABORT] had been
9783 ** specified as part of the users SQL statement, regardless of the actual
9784 ** ON CONFLICT mode specified.
9785 **
9786 ** If X is non-zero, then the virtual table implementation guarantees
9787 ** that if [xUpdate] returns [SQLITE_CONSTRAINT], it will do so before
9788 ** any modifications to internal or persistent data structures have been made.
9789 ** If the [ON CONFLICT] mode is ABORT, FAIL, IGNORE or ROLLBACK, SQLite
9790 ** is able to roll back a statement or database transaction, and abandon
9791 ** or continue processing the current SQL statement as appropriate.
9792 ** If the ON CONFLICT mode is REPLACE and the [xUpdate] method returns
9793 ** [SQLITE_CONSTRAINT], SQLite handles this as if the ON CONFLICT mode
9794 ** had been ABORT.
9795 **
9796 ** Virtual table implementations that are required to handle OR REPLACE
9797 ** must do so within the [xUpdate] method. If a call to the
9798 ** [sqlite3_vtab_on_conflict()] function indicates that the current ON
9799 ** CONFLICT policy is REPLACE, the virtual table implementation should
9800 ** silently replace the appropriate rows within the xUpdate callback and
9801 ** return SQLITE_OK. Or, if this is not possible, it may return
9802 ** SQLITE_CONSTRAINT, in which case SQLite falls back to OR ABORT
9803 ** constraint handling.
9804 ** </dd>
9805 **
9806 ** [[SQLITE_VTAB_DIRECTONLY]]<dt>SQLITE_VTAB_DIRECTONLY</dt>
9807 ** <dd>Calls of the form
9808 ** [sqlite3_vtab_config](db,SQLITE_VTAB_DIRECTONLY) from within the
9809 ** the [xConnect] or [xCreate] methods of a [virtual table] implementation
9810 ** prohibits that virtual table from being used from within triggers and
9811 ** views.
9812 ** </dd>
9813 **
9814 ** [[SQLITE_VTAB_INNOCUOUS]]<dt>SQLITE_VTAB_INNOCUOUS</dt>
9815 ** <dd>Calls of the form
9816 ** [sqlite3_vtab_config](db,SQLITE_VTAB_INNOCUOUS) from within the
9817 ** the [xConnect] or [xCreate] methods of a [virtual table] implementation
9818 ** identify that virtual table as being safe to use from within triggers
9819 ** and views. Conceptually, the SQLITE_VTAB_INNOCUOUS tag means that the
9820 ** virtual table can do no serious harm even if it is controlled by a
9821 ** malicious hacker. Developers should avoid setting the SQLITE_VTAB_INNOCUOUS
9822 ** flag unless absolutely necessary.
9823 ** </dd>
9824 **
9825 ** [[SQLITE_VTAB_USES_ALL_SCHEMAS]]<dt>SQLITE_VTAB_USES_ALL_SCHEMAS</dt>
9826 ** <dd>Calls of the form
9827 ** [sqlite3_vtab_config](db,SQLITE_VTAB_USES_ALL_SCHEMA) from within the
9828 ** the [xConnect] or [xCreate] methods of a [virtual table] implementation
9829 ** instruct the query planner to begin at least a read transaction on
9830 ** all schemas ("main", "temp", and any ATTACH-ed databases) whenever the
9831 ** virtual table is used.
9832 ** </dd>
9833 ** </dl>
9834 */
9835 #define SQLITE_VTAB_CONSTRAINT_SUPPORT 1
9836 #define SQLITE_VTAB_INNOCUOUS 2
9837 #define SQLITE_VTAB_DIRECTONLY 3
9838 #define SQLITE_VTAB_USES_ALL_SCHEMAS 4
9839
9840 /*
9841 ** CAPI3REF: Determine The Virtual Table Conflict Policy
9842 **
9843 ** This function may only be called from within a call to the [xUpdate] method
9844 ** of a [virtual table] implementation for an INSERT or UPDATE operation. ^The
9845 ** value returned is one of [SQLITE_ROLLBACK], [SQLITE_IGNORE], [SQLITE_FAIL],
9846 ** [SQLITE_ABORT], or [SQLITE_REPLACE], according to the [ON CONFLICT] mode
9847 ** of the SQL statement that triggered the call to the [xUpdate] method of the
9848 ** [virtual table].
9849 */
9850 SQLITE_API int sqlite3_vtab_on_conflict(sqlite3 *);
9851
9852 /*
9853 ** CAPI3REF: Determine If Virtual Table Column Access Is For UPDATE
9854 **
9855 ** If the sqlite3_vtab_nochange(X) routine is called within the [xColumn]
9856 ** method of a [virtual table], then it might return true if the
9857 ** column is being fetched as part of an UPDATE operation during which the
9858 ** column value will not change. The virtual table implementation can use
9859 ** this hint as permission to substitute a return value that is less
9860 ** expensive to compute and that the corresponding
9861 ** [xUpdate] method understands as a "no-change" value.
9862 **
9863 ** If the [xColumn] method calls sqlite3_vtab_nochange() and finds that
9864 ** the column is not changed by the UPDATE statement, then the xColumn
9865 ** method can optionally return without setting a result, without calling
9866 ** any of the [sqlite3_result_int|sqlite3_result_xxxxx() interfaces].
9867 ** In that case, [sqlite3_value_nochange(X)] will return true for the
9868 ** same column in the [xUpdate] method.
9869 **
9870 ** The sqlite3_vtab_nochange() routine is an optimization. Virtual table
9871 ** implementations should continue to give a correct answer even if the
9872 ** sqlite3_vtab_nochange() interface were to always return false. In the
9873 ** current implementation, the sqlite3_vtab_nochange() interface does always
9874 ** returns false for the enhanced [UPDATE FROM] statement.
9875 */
9876 SQLITE_API int sqlite3_vtab_nochange(sqlite3_context*);
9877
9878 /*
9879 ** CAPI3REF: Determine The Collation For a Virtual Table Constraint
9880 ** METHOD: sqlite3_index_info
9881 **
9882 ** This function may only be called from within a call to the [xBestIndex]
9883 ** method of a [virtual table]. This function returns a pointer to a string
9884 ** that is the name of the appropriate collation sequence to use for text
9885 ** comparisons on the constraint identified by its arguments.
9886 **
9887 ** The first argument must be the pointer to the [sqlite3_index_info] object
9888 ** that is the first parameter to the xBestIndex() method. The second argument
9889 ** must be an index into the aConstraint[] array belonging to the
9890 ** sqlite3_index_info structure passed to xBestIndex.
9891 **
9892 ** Important:
9893 ** The first parameter must be the same pointer that is passed into the
9894 ** xBestMethod() method. The first parameter may not be a pointer to a
9895 ** different [sqlite3_index_info] object, even an exact copy.
9896 **
9897 ** The return value is computed as follows:
9898 **
9899 ** <ol>
9900 ** <li><p> If the constraint comes from a WHERE clause expression that contains
9901 ** a [COLLATE operator], then the name of the collation specified by
9902 ** that COLLATE operator is returned.
9903 ** <li><p> If there is no COLLATE operator, but the column that is the subject
9904 ** of the constraint specifies an alternative collating sequence via
9905 ** a [COLLATE clause] on the column definition within the CREATE TABLE
9906 ** statement that was passed into [sqlite3_declare_vtab()], then the
9907 ** name of that alternative collating sequence is returned.
9908 ** <li><p> Otherwise, "BINARY" is returned.
9909 ** </ol>
9910 */
9911 SQLITE_API const char *sqlite3_vtab_collation(sqlite3_index_info*,int);
9912
9913 /*
9914 ** CAPI3REF: Determine if a virtual table query is DISTINCT
9915 ** METHOD: sqlite3_index_info
9916 **
9917 ** This API may only be used from within an [xBestIndex|xBestIndex method]
9918 ** of a [virtual table] implementation. The result of calling this
9919 ** interface from outside of xBestIndex() is undefined and probably harmful.
9920 **
9921 ** ^The sqlite3_vtab_distinct() interface returns an integer between 0 and
9922 ** 3. The integer returned by sqlite3_vtab_distinct()
9923 ** gives the virtual table additional information about how the query
9924 ** planner wants the output to be ordered. As long as the virtual table
9925 ** can meet the ordering requirements of the query planner, it may set
9926 ** the "orderByConsumed" flag.
9927 **
9928 ** <ol><li value="0"><p>
9929 ** ^If the sqlite3_vtab_distinct() interface returns 0, that means
9930 ** that the query planner needs the virtual table to return all rows in the
9931 ** sort order defined by the "nOrderBy" and "aOrderBy" fields of the
9932 ** [sqlite3_index_info] object. This is the default expectation. If the
9933 ** virtual table outputs all rows in sorted order, then it is always safe for
9934 ** the xBestIndex method to set the "orderByConsumed" flag, regardless of
9935 ** the return value from sqlite3_vtab_distinct().
9936 ** <li value="1"><p>
9937 ** ^(If the sqlite3_vtab_distinct() interface returns 1, that means
9938 ** that the query planner does not need the rows to be returned in sorted order
9939 ** as long as all rows with the same values in all columns identified by the
9940 ** "aOrderBy" field are adjacent.)^ This mode is used when the query planner
9941 ** is doing a GROUP BY.
9942 ** <li value="2"><p>
9943 ** ^(If the sqlite3_vtab_distinct() interface returns 2, that means
9944 ** that the query planner does not need the rows returned in any particular
9945 ** order, as long as rows with the same values in all columns identified
9946 ** by "aOrderBy" are adjacent.)^ ^(Furthermore, when two or more rows
9947 ** contain the same values for all columns identified by "colUsed", all but
9948 ** one such row may optionally be omitted from the result.)^
9949 ** The virtual table is not required to omit rows that are duplicates
9950 ** over the "colUsed" columns, but if the virtual table can do that without
9951 ** too much extra effort, it could potentially help the query to run faster.
9952 ** This mode is used for a DISTINCT query.
9953 ** <li value="3"><p>
9954 ** ^(If the sqlite3_vtab_distinct() interface returns 3, that means the
9955 ** virtual table must return rows in the order defined by "aOrderBy" as
9956 ** if the sqlite3_vtab_distinct() interface had returned 0. However if
9957 ** two or more rows in the result have the same values for all columns
9958 ** identified by "colUsed", then all but one such row may optionally be
9959 ** omitted.)^ Like when the return value is 2, the virtual table
9960 ** is not required to omit rows that are duplicates over the "colUsed"
9961 ** columns, but if the virtual table can do that without
9962 ** too much extra effort, it could potentially help the query to run faster.
9963 ** This mode is used for queries
9964 ** that have both DISTINCT and ORDER BY clauses.
9965 ** </ol>
9966 **
9967 ** <p>The following table summarizes the conditions under which the
9968 ** virtual table is allowed to set the "orderByConsumed" flag based on
9969 ** the value returned by sqlite3_vtab_distinct(). This table is a
9970 ** restatement of the previous four paragraphs:
9971 **
9972 ** <table border=1 cellspacing=0 cellpadding=10 width="90%">
9973 ** <tr>
9974 ** <td valign="top">sqlite3_vtab_distinct() return value
9975 ** <td valign="top">Rows are returned in aOrderBy order
9976 ** <td valign="top">Rows with the same value in all aOrderBy columns are adjacent
9977 ** <td valign="top">Duplicates over all colUsed columns may be omitted
9978 ** <tr><td>0<td>yes<td>yes<td>no
9979 ** <tr><td>1<td>no<td>yes<td>no
9980 ** <tr><td>2<td>no<td>yes<td>yes
9981 ** <tr><td>3<td>yes<td>yes<td>yes
9982 ** </table>
9983 **
9984 ** ^For the purposes of comparing virtual table output values to see if the
9985 ** values are same value for sorting purposes, two NULL values are considered
9986 ** to be the same. In other words, the comparison operator is "IS"
9987 ** (or "IS NOT DISTINCT FROM") and not "==".
9988 **
9989 ** If a virtual table implementation is unable to meet the requirements
9990 ** specified above, then it must not set the "orderByConsumed" flag in the
9991 ** [sqlite3_index_info] object or an incorrect answer may result.
9992 **
9993 ** ^A virtual table implementation is always free to return rows in any order
9994 ** it wants, as long as the "orderByConsumed" flag is not set. ^When the
9995 ** the "orderByConsumed" flag is unset, the query planner will add extra
9996 ** [bytecode] to ensure that the final results returned by the SQL query are
9997 ** ordered correctly. The use of the "orderByConsumed" flag and the
9998 ** sqlite3_vtab_distinct() interface is merely an optimization. ^Careful
9999 ** use of the sqlite3_vtab_distinct() interface and the "orderByConsumed"
10000 ** flag might help queries against a virtual table to run faster. Being
10001 ** overly aggressive and setting the "orderByConsumed" flag when it is not
10002 ** valid to do so, on the other hand, might cause SQLite to return incorrect
10003 ** results.
10004 */
10005 SQLITE_API int sqlite3_vtab_distinct(sqlite3_index_info*);
10006
10007 /*
10008 ** CAPI3REF: Identify and handle IN constraints in xBestIndex
10009 **
10010 ** This interface may only be used from within an
10011 ** [xBestIndex|xBestIndex() method] of a [virtual table] implementation.
10012 ** The result of invoking this interface from any other context is
10013 ** undefined and probably harmful.
10014 **
10015 ** ^(A constraint on a virtual table of the form
10016 ** "[IN operator|column IN (...)]" is
10017 ** communicated to the xBestIndex method as a
10018 ** [SQLITE_INDEX_CONSTRAINT_EQ] constraint.)^ If xBestIndex wants to use
10019 ** this constraint, it must set the corresponding
10020 ** aConstraintUsage[].argvIndex to a positive integer. ^(Then, under
10021 ** the usual mode of handling IN operators, SQLite generates [bytecode]
10022 ** that invokes the [xFilter|xFilter() method] once for each value
10023 ** on the right-hand side of the IN operator.)^ Thus the virtual table
10024 ** only sees a single value from the right-hand side of the IN operator
10025 ** at a time.
10026 **
10027 ** In some cases, however, it would be advantageous for the virtual
10028 ** table to see all values on the right-hand of the IN operator all at
10029 ** once. The sqlite3_vtab_in() interfaces facilitates this in two ways:
10030 **
10031 ** <ol>
10032 ** <li><p>
10033 ** ^A call to sqlite3_vtab_in(P,N,-1) will return true (non-zero)
10034 ** if and only if the [sqlite3_index_info|P->aConstraint][N] constraint
10035 ** is an [IN operator] that can be processed all at once. ^In other words,
10036 ** sqlite3_vtab_in() with -1 in the third argument is a mechanism
10037 ** by which the virtual table can ask SQLite if all-at-once processing
10038 ** of the IN operator is even possible.
10039 **
10040 ** <li><p>
10041 ** ^A call to sqlite3_vtab_in(P,N,F) with F==1 or F==0 indicates
10042 ** to SQLite that the virtual table does or does not want to process
10043 ** the IN operator all-at-once, respectively. ^Thus when the third
10044 ** parameter (F) is non-negative, this interface is the mechanism by
10045 ** which the virtual table tells SQLite how it wants to process the
10046 ** IN operator.
10047 ** </ol>
10048 **
10049 ** ^The sqlite3_vtab_in(P,N,F) interface can be invoked multiple times
10050 ** within the same xBestIndex method call. ^For any given P,N pair,
10051 ** the return value from sqlite3_vtab_in(P,N,F) will always be the same
10052 ** within the same xBestIndex call. ^If the interface returns true
10053 ** (non-zero), that means that the constraint is an IN operator
10054 ** that can be processed all-at-once. ^If the constraint is not an IN
10055 ** operator or cannot be processed all-at-once, then the interface returns
10056 ** false.
10057 **
10058 ** ^(All-at-once processing of the IN operator is selected if both of the
10059 ** following conditions are met:
10060 **
10061 ** <ol>
10062 ** <li><p> The P->aConstraintUsage[N].argvIndex value is set to a positive
10063 ** integer. This is how the virtual table tells SQLite that it wants to
10064 ** use the N-th constraint.
10065 **
10066 ** <li><p> The last call to sqlite3_vtab_in(P,N,F) for which F was
10067 ** non-negative had F>=1.
10068 ** </ol>)^
10069 **
10070 ** ^If either or both of the conditions above are false, then SQLite uses
10071 ** the traditional one-at-a-time processing strategy for the IN constraint.
10072 ** ^If both conditions are true, then the argvIndex-th parameter to the
10073 ** xFilter method will be an [sqlite3_value] that appears to be NULL,
10074 ** but which can be passed to [sqlite3_vtab_in_first()] and
10075 ** [sqlite3_vtab_in_next()] to find all values on the right-hand side
10076 ** of the IN constraint.
10077 */
10078 SQLITE_API int sqlite3_vtab_in(sqlite3_index_info*, int iCons, int bHandle);
10079
10080 /*
10081 ** CAPI3REF: Find all elements on the right-hand side of an IN constraint.
10082 **
10083 ** These interfaces are only useful from within the
10084 ** [xFilter|xFilter() method] of a [virtual table] implementation.
10085 ** The result of invoking these interfaces from any other context
10086 ** is undefined and probably harmful.
10087 **
10088 ** The X parameter in a call to sqlite3_vtab_in_first(X,P) or
10089 ** sqlite3_vtab_in_next(X,P) should be one of the parameters to the
10090 ** xFilter method which invokes these routines, and specifically
10091 ** a parameter that was previously selected for all-at-once IN constraint
10092 ** processing use the [sqlite3_vtab_in()] interface in the
10093 ** [xBestIndex|xBestIndex method]. ^(If the X parameter is not
10094 ** an xFilter argument that was selected for all-at-once IN constraint
10095 ** processing, then these routines return [SQLITE_ERROR].)^
10096 **
10097 ** ^(Use these routines to access all values on the right-hand side
10098 ** of the IN constraint using code like the following:
10099 **
10100 ** <blockquote><pre>
10101 ** &nbsp; for(rc=sqlite3_vtab_in_first(pList, &pVal);
10102 ** &nbsp; rc==SQLITE_OK && pVal;
10103 ** &nbsp; rc=sqlite3_vtab_in_next(pList, &pVal)
10104 ** &nbsp; ){
10105 ** &nbsp; // do something with pVal
10106 ** &nbsp; }
10107 ** &nbsp; if( rc!=SQLITE_OK ){
10108 ** &nbsp; // an error has occurred
10109 ** &nbsp; }
10110 ** </pre></blockquote>)^
10111 **
10112 ** ^On success, the sqlite3_vtab_in_first(X,P) and sqlite3_vtab_in_next(X,P)
10113 ** routines return SQLITE_OK and set *P to point to the first or next value
10114 ** on the RHS of the IN constraint. ^If there are no more values on the
10115 ** right hand side of the IN constraint, then *P is set to NULL and these
10116 ** routines return [SQLITE_DONE]. ^The return value might be
10117 ** some other value, such as SQLITE_NOMEM, in the event of a malfunction.
10118 **
10119 ** The *ppOut values returned by these routines are only valid until the
10120 ** next call to either of these routines or until the end of the xFilter
10121 ** method from which these routines were called. If the virtual table
10122 ** implementation needs to retain the *ppOut values for longer, it must make
10123 ** copies. The *ppOut values are [protected sqlite3_value|protected].
10124 */
10125 SQLITE_API int sqlite3_vtab_in_first(sqlite3_value *pVal, sqlite3_value **ppOut);
10126 SQLITE_API int sqlite3_vtab_in_next(sqlite3_value *pVal, sqlite3_value **ppOut);
10127
10128 /*
10129 ** CAPI3REF: Constraint values in xBestIndex()
10130 ** METHOD: sqlite3_index_info
10131 **
10132 ** This API may only be used from within the [xBestIndex|xBestIndex method]
10133 ** of a [virtual table] implementation. The result of calling this interface
10134 ** from outside of an xBestIndex method are undefined and probably harmful.
10135 **
10136 ** ^When the sqlite3_vtab_rhs_value(P,J,V) interface is invoked from within
10137 ** the [xBestIndex] method of a [virtual table] implementation, with P being
10138 ** a copy of the [sqlite3_index_info] object pointer passed into xBestIndex and
10139 ** J being a 0-based index into P->aConstraint[], then this routine
10140 ** attempts to set *V to the value of the right-hand operand of
10141 ** that constraint if the right-hand operand is known. ^If the
10142 ** right-hand operand is not known, then *V is set to a NULL pointer.
10143 ** ^The sqlite3_vtab_rhs_value(P,J,V) interface returns SQLITE_OK if
10144 ** and only if *V is set to a value. ^The sqlite3_vtab_rhs_value(P,J,V)
10145 ** inteface returns SQLITE_NOTFOUND if the right-hand side of the J-th
10146 ** constraint is not available. ^The sqlite3_vtab_rhs_value() interface
10147 ** can return an result code other than SQLITE_OK or SQLITE_NOTFOUND if
10148 ** something goes wrong.
10149 **
10150 ** The sqlite3_vtab_rhs_value() interface is usually only successful if
10151 ** the right-hand operand of a constraint is a literal value in the original
10152 ** SQL statement. If the right-hand operand is an expression or a reference
10153 ** to some other column or a [host parameter], then sqlite3_vtab_rhs_value()
10154 ** will probably return [SQLITE_NOTFOUND].
10155 **
10156 ** ^(Some constraints, such as [SQLITE_INDEX_CONSTRAINT_ISNULL] and
10157 ** [SQLITE_INDEX_CONSTRAINT_ISNOTNULL], have no right-hand operand. For such
10158 ** constraints, sqlite3_vtab_rhs_value() always returns SQLITE_NOTFOUND.)^
10159 **
10160 ** ^The [sqlite3_value] object returned in *V is a protected sqlite3_value
10161 ** and remains valid for the duration of the xBestIndex method call.
10162 ** ^When xBestIndex returns, the sqlite3_value object returned by
10163 ** sqlite3_vtab_rhs_value() is automatically deallocated.
10164 **
10165 ** The "_rhs_" in the name of this routine is an abbreviation for
10166 ** "Right-Hand Side".
10167 */
10168 SQLITE_API int sqlite3_vtab_rhs_value(sqlite3_index_info*, int, sqlite3_value **ppVal);
10169
10170 /*
10171 ** CAPI3REF: Conflict resolution modes
10172 ** KEYWORDS: {conflict resolution mode}
10173 **
10174 ** These constants are returned by [sqlite3_vtab_on_conflict()] to
10175 ** inform a [virtual table] implementation what the [ON CONFLICT] mode
10176 ** is for the SQL statement being evaluated.
10177 **
10178 ** Note that the [SQLITE_IGNORE] constant is also used as a potential
10179 ** return value from the [sqlite3_set_authorizer()] callback and that
10180 ** [SQLITE_ABORT] is also a [result code].
10181 */
10182 #define SQLITE_ROLLBACK 1
10183 /* #define SQLITE_IGNORE 2 // Also used by sqlite3_authorizer() callback */
10184 #define SQLITE_FAIL 3
10185 /* #define SQLITE_ABORT 4 // Also an error code */
10186 #define SQLITE_REPLACE 5
10187
10188 /*
10189 ** CAPI3REF: Prepared Statement Scan Status Opcodes
10190 ** KEYWORDS: {scanstatus options}
10191 **
10192 ** The following constants can be used for the T parameter to the
10193 ** [sqlite3_stmt_scanstatus(S,X,T,V)] interface. Each constant designates a
10194 ** different metric for sqlite3_stmt_scanstatus() to return.
10195 **
10196 ** When the value returned to V is a string, space to hold that string is
10197 ** managed by the prepared statement S and will be automatically freed when
10198 ** S is finalized.
10199 **
10200 ** Not all values are available for all query elements. When a value is
10201 ** not available, the output variable is set to -1 if the value is numeric,
10202 ** or to NULL if it is a string (SQLITE_SCANSTAT_NAME).
10203 **
10204 ** <dl>
10205 ** [[SQLITE_SCANSTAT_NLOOP]] <dt>SQLITE_SCANSTAT_NLOOP</dt>
10206 ** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be
10207 ** set to the total number of times that the X-th loop has run.</dd>
10208 **
10209 ** [[SQLITE_SCANSTAT_NVISIT]] <dt>SQLITE_SCANSTAT_NVISIT</dt>
10210 ** <dd>^The [sqlite3_int64] variable pointed to by the V parameter will be set
10211 ** to the total number of rows examined by all iterations of the X-th loop.</dd>
10212 **
10213 ** [[SQLITE_SCANSTAT_EST]] <dt>SQLITE_SCANSTAT_EST</dt>
10214 ** <dd>^The "double" variable pointed to by the V parameter will be set to the
10215 ** query planner's estimate for the average number of rows output from each
10216 ** iteration of the X-th loop. If the query planner's estimates was accurate,
10217 ** then this value will approximate the quotient NVISIT/NLOOP and the
10218 ** product of this value for all prior loops with the same SELECTID will
10219 ** be the NLOOP value for the current loop.
10220 **
10221 ** [[SQLITE_SCANSTAT_NAME]] <dt>SQLITE_SCANSTAT_NAME</dt>
10222 ** <dd>^The "const char *" variable pointed to by the V parameter will be set
10223 ** to a zero-terminated UTF-8 string containing the name of the index or table
10224 ** used for the X-th loop.
10225 **
10226 ** [[SQLITE_SCANSTAT_EXPLAIN]] <dt>SQLITE_SCANSTAT_EXPLAIN</dt>
10227 ** <dd>^The "const char *" variable pointed to by the V parameter will be set
10228 ** to a zero-terminated UTF-8 string containing the [EXPLAIN QUERY PLAN]
10229 ** description for the X-th loop.
10230 **
10231 ** [[SQLITE_SCANSTAT_SELECTID]] <dt>SQLITE_SCANSTAT_SELECTID</dt>
10232 ** <dd>^The "int" variable pointed to by the V parameter will be set to the
10233 ** id for the X-th query plan element. The id value is unique within the
10234 ** statement. The select-id is the same value as is output in the first
10235 ** column of an [EXPLAIN QUERY PLAN] query.
10236 **
10237 ** [[SQLITE_SCANSTAT_PARENTID]] <dt>SQLITE_SCANSTAT_PARENTID</dt>
10238 ** <dd>The "int" variable pointed to by the V parameter will be set to the
10239 ** the id of the parent of the current query element, if applicable, or
10240 ** to zero if the query element has no parent. This is the same value as
10241 ** returned in the second column of an [EXPLAIN QUERY PLAN] query.
10242 **
10243 ** [[SQLITE_SCANSTAT_NCYCLE]] <dt>SQLITE_SCANSTAT_NCYCLE</dt>
10244 ** <dd>The sqlite3_int64 output value is set to the number of cycles,
10245 ** according to the processor time-stamp counter, that elapsed while the
10246 ** query element was being processed. This value is not available for
10247 ** all query elements - if it is unavailable the output variable is
10248 ** set to -1.
10249 ** </dl>
10250 */
10251 #define SQLITE_SCANSTAT_NLOOP 0
10252 #define SQLITE_SCANSTAT_NVISIT 1
10253 #define SQLITE_SCANSTAT_EST 2
10254 #define SQLITE_SCANSTAT_NAME 3
10255 #define SQLITE_SCANSTAT_EXPLAIN 4
10256 #define SQLITE_SCANSTAT_SELECTID 5
10257 #define SQLITE_SCANSTAT_PARENTID 6
10258 #define SQLITE_SCANSTAT_NCYCLE 7
10259
10260 /*
10261 ** CAPI3REF: Prepared Statement Scan Status
10262 ** METHOD: sqlite3_stmt
10263 **
10264 ** These interfaces return information about the predicted and measured
10265 ** performance for pStmt. Advanced applications can use this
10266 ** interface to compare the predicted and the measured performance and
10267 ** issue warnings and/or rerun [ANALYZE] if discrepancies are found.
10268 **
10269 ** Since this interface is expected to be rarely used, it is only
10270 ** available if SQLite is compiled using the [SQLITE_ENABLE_STMT_SCANSTATUS]
10271 ** compile-time option.
10272 **
10273 ** The "iScanStatusOp" parameter determines which status information to return.
10274 ** The "iScanStatusOp" must be one of the [scanstatus options] or the behavior
10275 ** of this interface is undefined. ^The requested measurement is written into
10276 ** a variable pointed to by the "pOut" parameter.
10277 **
10278 ** The "flags" parameter must be passed a mask of flags. At present only
10279 ** one flag is defined - SQLITE_SCANSTAT_COMPLEX. If SQLITE_SCANSTAT_COMPLEX
10280 ** is specified, then status information is available for all elements
10281 ** of a query plan that are reported by "EXPLAIN QUERY PLAN" output. If
10282 ** SQLITE_SCANSTAT_COMPLEX is not specified, then only query plan elements
10283 ** that correspond to query loops (the "SCAN..." and "SEARCH..." elements of
10284 ** the EXPLAIN QUERY PLAN output) are available. Invoking API
10285 ** sqlite3_stmt_scanstatus() is equivalent to calling
10286 ** sqlite3_stmt_scanstatus_v2() with a zeroed flags parameter.
10287 **
10288 ** Parameter "idx" identifies the specific query element to retrieve statistics
10289 ** for. Query elements are numbered starting from zero. A value of -1 may be
10290 ** to query for statistics regarding the entire query. ^If idx is out of range
10291 ** - less than -1 or greater than or equal to the total number of query
10292 ** elements used to implement the statement - a non-zero value is returned and
10293 ** the variable that pOut points to is unchanged.
10294 **
10295 ** See also: [sqlite3_stmt_scanstatus_reset()]
10296 */
10297 SQLITE_API int sqlite3_stmt_scanstatus(
10298 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */
10299 int idx, /* Index of loop to report on */
10300 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */
10301 void *pOut /* Result written here */
10302 );
10303 SQLITE_API int sqlite3_stmt_scanstatus_v2(
10304 sqlite3_stmt *pStmt, /* Prepared statement for which info desired */
10305 int idx, /* Index of loop to report on */
10306 int iScanStatusOp, /* Information desired. SQLITE_SCANSTAT_* */
10307 int flags, /* Mask of flags defined below */
10308 void *pOut /* Result written here */
10309 );
10310
10311 /*
10312 ** CAPI3REF: Prepared Statement Scan Status
10313 ** KEYWORDS: {scan status flags}
10314 */
10315 #define SQLITE_SCANSTAT_COMPLEX 0x0001
10316
10317 /*
10318 ** CAPI3REF: Zero Scan-Status Counters
10319 ** METHOD: sqlite3_stmt
10320 **
10321 ** ^Zero all [sqlite3_stmt_scanstatus()] related event counters.
10322 **
10323 ** This API is only available if the library is built with pre-processor
10324 ** symbol [SQLITE_ENABLE_STMT_SCANSTATUS] defined.
10325 */
10326 SQLITE_API void sqlite3_stmt_scanstatus_reset(sqlite3_stmt*);
10327
10328 /*
10329 ** CAPI3REF: Flush caches to disk mid-transaction
10330 ** METHOD: sqlite3
10331 **
10332 ** ^If a write-transaction is open on [database connection] D when the
10333 ** [sqlite3_db_cacheflush(D)] interface invoked, any dirty
10334 ** pages in the pager-cache that are not currently in use are written out
10335 ** to disk. A dirty page may be in use if a database cursor created by an
10336 ** active SQL statement is reading from it, or if it is page 1 of a database
10337 ** file (page 1 is always "in use"). ^The [sqlite3_db_cacheflush(D)]
10338 ** interface flushes caches for all schemas - "main", "temp", and
10339 ** any [attached] databases.
10340 **
10341 ** ^If this function needs to obtain extra database locks before dirty pages
10342 ** can be flushed to disk, it does so. ^If those locks cannot be obtained
10343 ** immediately and there is a busy-handler callback configured, it is invoked
10344 ** in the usual manner. ^If the required lock still cannot be obtained, then
10345 ** the database is skipped and an attempt made to flush any dirty pages
10346 ** belonging to the next (if any) database. ^If any databases are skipped
10347 ** because locks cannot be obtained, but no other error occurs, this
10348 ** function returns SQLITE_BUSY.
10349 **
10350 ** ^If any other error occurs while flushing dirty pages to disk (for
10351 ** example an IO error or out-of-memory condition), then processing is
10352 ** abandoned and an SQLite [error code] is returned to the caller immediately.
10353 **
10354 ** ^Otherwise, if no error occurs, [sqlite3_db_cacheflush()] returns SQLITE_OK.
10355 **
10356 ** ^This function does not set the database handle error code or message
10357 ** returned by the [sqlite3_errcode()] and [sqlite3_errmsg()] functions.
10358 */
10359 SQLITE_API int sqlite3_db_cacheflush(sqlite3*);
10360
10361 /*
10362 ** CAPI3REF: The pre-update hook.
10363 ** METHOD: sqlite3
10364 **
10365 ** ^These interfaces are only available if SQLite is compiled using the
10366 ** [SQLITE_ENABLE_PREUPDATE_HOOK] compile-time option.
10367 **
10368 ** ^The [sqlite3_preupdate_hook()] interface registers a callback function
10369 ** that is invoked prior to each [INSERT], [UPDATE], and [DELETE] operation
10370 ** on a database table.
10371 ** ^At most one preupdate hook may be registered at a time on a single
10372 ** [database connection]; each call to [sqlite3_preupdate_hook()] overrides
10373 ** the previous setting.
10374 ** ^The preupdate hook is disabled by invoking [sqlite3_preupdate_hook()]
10375 ** with a NULL pointer as the second parameter.
10376 ** ^The third parameter to [sqlite3_preupdate_hook()] is passed through as
10377 ** the first parameter to callbacks.
10378 **
10379 ** ^The preupdate hook only fires for changes to real database tables; the
10380 ** preupdate hook is not invoked for changes to [virtual tables] or to
10381 ** system tables like sqlite_sequence or sqlite_stat1.
10382 **
10383 ** ^The second parameter to the preupdate callback is a pointer to
10384 ** the [database connection] that registered the preupdate hook.
10385 ** ^The third parameter to the preupdate callback is one of the constants
10386 ** [SQLITE_INSERT], [SQLITE_DELETE], or [SQLITE_UPDATE] to identify the
10387 ** kind of update operation that is about to occur.
10388 ** ^(The fourth parameter to the preupdate callback is the name of the
10389 ** database within the database connection that is being modified. This
10390 ** will be "main" for the main database or "temp" for TEMP tables or
10391 ** the name given after the AS keyword in the [ATTACH] statement for attached
10392 ** databases.)^
10393 ** ^The fifth parameter to the preupdate callback is the name of the
10394 ** table that is being modified.
10395 **
10396 ** For an UPDATE or DELETE operation on a [rowid table], the sixth
10397 ** parameter passed to the preupdate callback is the initial [rowid] of the
10398 ** row being modified or deleted. For an INSERT operation on a rowid table,
10399 ** or any operation on a WITHOUT ROWID table, the value of the sixth
10400 ** parameter is undefined. For an INSERT or UPDATE on a rowid table the
10401 ** seventh parameter is the final rowid value of the row being inserted
10402 ** or updated. The value of the seventh parameter passed to the callback
10403 ** function is not defined for operations on WITHOUT ROWID tables, or for
10404 ** DELETE operations on rowid tables.
10405 **
10406 ** ^The sqlite3_preupdate_hook(D,C,P) function returns the P argument from
10407 ** the previous call on the same [database connection] D, or NULL for
10408 ** the first call on D.
10409 **
10410 ** The [sqlite3_preupdate_old()], [sqlite3_preupdate_new()],
10411 ** [sqlite3_preupdate_count()], and [sqlite3_preupdate_depth()] interfaces
10412 ** provide additional information about a preupdate event. These routines
10413 ** may only be called from within a preupdate callback. Invoking any of
10414 ** these routines from outside of a preupdate callback or with a
10415 ** [database connection] pointer that is different from the one supplied
10416 ** to the preupdate callback results in undefined and probably undesirable
10417 ** behavior.
10418 **
10419 ** ^The [sqlite3_preupdate_count(D)] interface returns the number of columns
10420 ** in the row that is being inserted, updated, or deleted.
10421 **
10422 ** ^The [sqlite3_preupdate_old(D,N,P)] interface writes into P a pointer to
10423 ** a [protected sqlite3_value] that contains the value of the Nth column of
10424 ** the table row before it is updated. The N parameter must be between 0
10425 ** and one less than the number of columns or the behavior will be
10426 ** undefined. This must only be used within SQLITE_UPDATE and SQLITE_DELETE
10427 ** preupdate callbacks; if it is used by an SQLITE_INSERT callback then the
10428 ** behavior is undefined. The [sqlite3_value] that P points to
10429 ** will be destroyed when the preupdate callback returns.
10430 **
10431 ** ^The [sqlite3_preupdate_new(D,N,P)] interface writes into P a pointer to
10432 ** a [protected sqlite3_value] that contains the value of the Nth column of
10433 ** the table row after it is updated. The N parameter must be between 0
10434 ** and one less than the number of columns or the behavior will be
10435 ** undefined. This must only be used within SQLITE_INSERT and SQLITE_UPDATE
10436 ** preupdate callbacks; if it is used by an SQLITE_DELETE callback then the
10437 ** behavior is undefined. The [sqlite3_value] that P points to
10438 ** will be destroyed when the preupdate callback returns.
10439 **
10440 ** ^The [sqlite3_preupdate_depth(D)] interface returns 0 if the preupdate
10441 ** callback was invoked as a result of a direct insert, update, or delete
10442 ** operation; or 1 for inserts, updates, or deletes invoked by top-level
10443 ** triggers; or 2 for changes resulting from triggers called by top-level
10444 ** triggers; and so forth.
10445 **
10446 ** When the [sqlite3_blob_write()] API is used to update a blob column,
10447 ** the pre-update hook is invoked with SQLITE_DELETE. This is because the
10448 ** in this case the new values are not available. In this case, when a
10449 ** callback made with op==SQLITE_DELETE is actually a write using the
10450 ** sqlite3_blob_write() API, the [sqlite3_preupdate_blobwrite()] returns
10451 ** the index of the column being written. In other cases, where the
10452 ** pre-update hook is being invoked for some other reason, including a
10453 ** regular DELETE, sqlite3_preupdate_blobwrite() returns -1.
10454 **
10455 ** See also: [sqlite3_update_hook()]
10456 */
10457 #if defined(SQLITE_ENABLE_PREUPDATE_HOOK)
10458 SQLITE_API void *sqlite3_preupdate_hook(
10459 sqlite3 *db,
10460 void(*xPreUpdate)(
10461 void *pCtx, /* Copy of third arg to preupdate_hook() */
10462 sqlite3 *db, /* Database handle */
10463 int op, /* SQLITE_UPDATE, DELETE or INSERT */
10464 char const *zDb, /* Database name */
10465 char const *zName, /* Table name */
10466 sqlite3_int64 iKey1, /* Rowid of row about to be deleted/updated */
10467 sqlite3_int64 iKey2 /* New rowid value (for a rowid UPDATE) */
10468 ),
10469 void*
10470 );
10471 SQLITE_API int sqlite3_preupdate_old(sqlite3 *, int, sqlite3_value **);
10472 SQLITE_API int sqlite3_preupdate_count(sqlite3 *);
10473 SQLITE_API int sqlite3_preupdate_depth(sqlite3 *);
10474 SQLITE_API int sqlite3_preupdate_new(sqlite3 *, int, sqlite3_value **);
10475 SQLITE_API int sqlite3_preupdate_blobwrite(sqlite3 *);
10476 #endif
10477
10478 /*
10479 ** CAPI3REF: Low-level system error code
10480 ** METHOD: sqlite3
10481 **
10482 ** ^Attempt to return the underlying operating system error code or error
10483 ** number that caused the most recent I/O error or failure to open a file.
10484 ** The return value is OS-dependent. For example, on unix systems, after
10485 ** [sqlite3_open_v2()] returns [SQLITE_CANTOPEN], this interface could be
10486 ** called to get back the underlying "errno" that caused the problem, such
10487 ** as ENOSPC, EAUTH, EISDIR, and so forth.
10488 */
10489 SQLITE_API int sqlite3_system_errno(sqlite3*);
10490
10491 /*
10492 ** CAPI3REF: Database Snapshot
10493 ** KEYWORDS: {snapshot} {sqlite3_snapshot}
10494 **
10495 ** An instance of the snapshot object records the state of a [WAL mode]
10496 ** database for some specific point in history.
10497 **
10498 ** In [WAL mode], multiple [database connections] that are open on the
10499 ** same database file can each be reading a different historical version
10500 ** of the database file. When a [database connection] begins a read
10501 ** transaction, that connection sees an unchanging copy of the database
10502 ** as it existed for the point in time when the transaction first started.
10503 ** Subsequent changes to the database from other connections are not seen
10504 ** by the reader until a new read transaction is started.
10505 **
10506 ** The sqlite3_snapshot object records state information about an historical
10507 ** version of the database file so that it is possible to later open a new read
10508 ** transaction that sees that historical version of the database rather than
10509 ** the most recent version.
10510 */
10511 typedef struct sqlite3_snapshot {
10512 unsigned char hidden[48];
10513 } sqlite3_snapshot;
10514
10515 /*
10516 ** CAPI3REF: Record A Database Snapshot
10517 ** CONSTRUCTOR: sqlite3_snapshot
10518 **
10519 ** ^The [sqlite3_snapshot_get(D,S,P)] interface attempts to make a
10520 ** new [sqlite3_snapshot] object that records the current state of
10521 ** schema S in database connection D. ^On success, the
10522 ** [sqlite3_snapshot_get(D,S,P)] interface writes a pointer to the newly
10523 ** created [sqlite3_snapshot] object into *P and returns SQLITE_OK.
10524 ** If there is not already a read-transaction open on schema S when
10525 ** this function is called, one is opened automatically.
10526 **
10527 ** The following must be true for this function to succeed. If any of
10528 ** the following statements are false when sqlite3_snapshot_get() is
10529 ** called, SQLITE_ERROR is returned. The final value of *P is undefined
10530 ** in this case.
10531 **
10532 ** <ul>
10533 ** <li> The database handle must not be in [autocommit mode].
10534 **
10535 ** <li> Schema S of [database connection] D must be a [WAL mode] database.
10536 **
10537 ** <li> There must not be a write transaction open on schema S of database
10538 ** connection D.
10539 **
10540 ** <li> One or more transactions must have been written to the current wal
10541 ** file since it was created on disk (by any connection). This means
10542 ** that a snapshot cannot be taken on a wal mode database with no wal
10543 ** file immediately after it is first opened. At least one transaction
10544 ** must be written to it first.
10545 ** </ul>
10546 **
10547 ** This function may also return SQLITE_NOMEM. If it is called with the
10548 ** database handle in autocommit mode but fails for some other reason,
10549 ** whether or not a read transaction is opened on schema S is undefined.
10550 **
10551 ** The [sqlite3_snapshot] object returned from a successful call to
10552 ** [sqlite3_snapshot_get()] must be freed using [sqlite3_snapshot_free()]
10553 ** to avoid a memory leak.
10554 **
10555 ** The [sqlite3_snapshot_get()] interface is only available when the
10556 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
10557 */
10558 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_get(
10559 sqlite3 *db,
10560 const char *zSchema,
10561 sqlite3_snapshot **ppSnapshot
10562 );
10563
10564 /*
10565 ** CAPI3REF: Start a read transaction on an historical snapshot
10566 ** METHOD: sqlite3_snapshot
10567 **
10568 ** ^The [sqlite3_snapshot_open(D,S,P)] interface either starts a new read
10569 ** transaction or upgrades an existing one for schema S of
10570 ** [database connection] D such that the read transaction refers to
10571 ** historical [snapshot] P, rather than the most recent change to the
10572 ** database. ^The [sqlite3_snapshot_open()] interface returns SQLITE_OK
10573 ** on success or an appropriate [error code] if it fails.
10574 **
10575 ** ^In order to succeed, the database connection must not be in
10576 ** [autocommit mode] when [sqlite3_snapshot_open(D,S,P)] is called. If there
10577 ** is already a read transaction open on schema S, then the database handle
10578 ** must have no active statements (SELECT statements that have been passed
10579 ** to sqlite3_step() but not sqlite3_reset() or sqlite3_finalize()).
10580 ** SQLITE_ERROR is returned if either of these conditions is violated, or
10581 ** if schema S does not exist, or if the snapshot object is invalid.
10582 **
10583 ** ^A call to sqlite3_snapshot_open() will fail to open if the specified
10584 ** snapshot has been overwritten by a [checkpoint]. In this case
10585 ** SQLITE_ERROR_SNAPSHOT is returned.
10586 **
10587 ** If there is already a read transaction open when this function is
10588 ** invoked, then the same read transaction remains open (on the same
10589 ** database snapshot) if SQLITE_ERROR, SQLITE_BUSY or SQLITE_ERROR_SNAPSHOT
10590 ** is returned. If another error code - for example SQLITE_PROTOCOL or an
10591 ** SQLITE_IOERR error code - is returned, then the final state of the
10592 ** read transaction is undefined. If SQLITE_OK is returned, then the
10593 ** read transaction is now open on database snapshot P.
10594 **
10595 ** ^(A call to [sqlite3_snapshot_open(D,S,P)] will fail if the
10596 ** database connection D does not know that the database file for
10597 ** schema S is in [WAL mode]. A database connection might not know
10598 ** that the database file is in [WAL mode] if there has been no prior
10599 ** I/O on that database connection, or if the database entered [WAL mode]
10600 ** after the most recent I/O on the database connection.)^
10601 ** (Hint: Run "[PRAGMA application_id]" against a newly opened
10602 ** database connection in order to make it ready to use snapshots.)
10603 **
10604 ** The [sqlite3_snapshot_open()] interface is only available when the
10605 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
10606 */
10607 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_open(
10608 sqlite3 *db,
10609 const char *zSchema,
10610 sqlite3_snapshot *pSnapshot
10611 );
10612
10613 /*
10614 ** CAPI3REF: Destroy a snapshot
10615 ** DESTRUCTOR: sqlite3_snapshot
10616 **
10617 ** ^The [sqlite3_snapshot_free(P)] interface destroys [sqlite3_snapshot] P.
10618 ** The application must eventually free every [sqlite3_snapshot] object
10619 ** using this routine to avoid a memory leak.
10620 **
10621 ** The [sqlite3_snapshot_free()] interface is only available when the
10622 ** [SQLITE_ENABLE_SNAPSHOT] compile-time option is used.
10623 */
10624 SQLITE_API SQLITE_EXPERIMENTAL void sqlite3_snapshot_free(sqlite3_snapshot*);
10625
10626 /*
10627 ** CAPI3REF: Compare the ages of two snapshot handles.
10628 ** METHOD: sqlite3_snapshot
10629 **
10630 ** The sqlite3_snapshot_cmp(P1, P2) interface is used to compare the ages
10631 ** of two valid snapshot handles.
10632 **
10633 ** If the two snapshot handles are not associated with the same database
10634 ** file, the result of the comparison is undefined.
10635 **
10636 ** Additionally, the result of the comparison is only valid if both of the
10637 ** snapshot handles were obtained by calling sqlite3_snapshot_get() since the
10638 ** last time the wal file was deleted. The wal file is deleted when the
10639 ** database is changed back to rollback mode or when the number of database
10640 ** clients drops to zero. If either snapshot handle was obtained before the
10641 ** wal file was last deleted, the value returned by this function
10642 ** is undefined.
10643 **
10644 ** Otherwise, this API returns a negative value if P1 refers to an older
10645 ** snapshot than P2, zero if the two handles refer to the same database
10646 ** snapshot, and a positive value if P1 is a newer snapshot than P2.
10647 **
10648 ** This interface is only available if SQLite is compiled with the
10649 ** [SQLITE_ENABLE_SNAPSHOT] option.
10650 */
10651 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_cmp(
10652 sqlite3_snapshot *p1,
10653 sqlite3_snapshot *p2
10654 );
10655
10656 /*
10657 ** CAPI3REF: Recover snapshots from a wal file
10658 ** METHOD: sqlite3_snapshot
10659 **
10660 ** If a [WAL file] remains on disk after all database connections close
10661 ** (either through the use of the [SQLITE_FCNTL_PERSIST_WAL] [file control]
10662 ** or because the last process to have the database opened exited without
10663 ** calling [sqlite3_close()]) and a new connection is subsequently opened
10664 ** on that database and [WAL file], the [sqlite3_snapshot_open()] interface
10665 ** will only be able to open the last transaction added to the WAL file
10666 ** even though the WAL file contains other valid transactions.
10667 **
10668 ** This function attempts to scan the WAL file associated with database zDb
10669 ** of database handle db and make all valid snapshots available to
10670 ** sqlite3_snapshot_open(). It is an error if there is already a read
10671 ** transaction open on the database, or if the database is not a WAL mode
10672 ** database.
10673 **
10674 ** SQLITE_OK is returned if successful, or an SQLite error code otherwise.
10675 **
10676 ** This interface is only available if SQLite is compiled with the
10677 ** [SQLITE_ENABLE_SNAPSHOT] option.
10678 */
10679 SQLITE_API SQLITE_EXPERIMENTAL int sqlite3_snapshot_recover(sqlite3 *db, const char *zDb);
10680
10681 /*
10682 ** CAPI3REF: Serialize a database
10683 **
10684 ** The sqlite3_serialize(D,S,P,F) interface returns a pointer to memory
10685 ** that is a serialization of the S database on [database connection] D.
10686 ** If P is not a NULL pointer, then the size of the database in bytes
10687 ** is written into *P.
10688 **
10689 ** For an ordinary on-disk database file, the serialization is just a
10690 ** copy of the disk file. For an in-memory database or a "TEMP" database,
10691 ** the serialization is the same sequence of bytes which would be written
10692 ** to disk if that database where backed up to disk.
10693 **
10694 ** The usual case is that sqlite3_serialize() copies the serialization of
10695 ** the database into memory obtained from [sqlite3_malloc64()] and returns
10696 ** a pointer to that memory. The caller is responsible for freeing the
10697 ** returned value to avoid a memory leak. However, if the F argument
10698 ** contains the SQLITE_SERIALIZE_NOCOPY bit, then no memory allocations
10699 ** are made, and the sqlite3_serialize() function will return a pointer
10700 ** to the contiguous memory representation of the database that SQLite
10701 ** is currently using for that database, or NULL if the no such contiguous
10702 ** memory representation of the database exists. A contiguous memory
10703 ** representation of the database will usually only exist if there has
10704 ** been a prior call to [sqlite3_deserialize(D,S,...)] with the same
10705 ** values of D and S.
10706 ** The size of the database is written into *P even if the
10707 ** SQLITE_SERIALIZE_NOCOPY bit is set but no contiguous copy
10708 ** of the database exists.
10709 **
10710 ** After the call, if the SQLITE_SERIALIZE_NOCOPY bit had been set,
10711 ** the returned buffer content will remain accessible and unchanged
10712 ** until either the next write operation on the connection or when
10713 ** the connection is closed, and applications must not modify the
10714 ** buffer. If the bit had been clear, the returned buffer will not
10715 ** be accessed by SQLite after the call.
10716 **
10717 ** A call to sqlite3_serialize(D,S,P,F) might return NULL even if the
10718 ** SQLITE_SERIALIZE_NOCOPY bit is omitted from argument F if a memory
10719 ** allocation error occurs.
10720 **
10721 ** This interface is omitted if SQLite is compiled with the
10722 ** [SQLITE_OMIT_DESERIALIZE] option.
10723 */
10724 SQLITE_API unsigned char *sqlite3_serialize(
10725 sqlite3 *db, /* The database connection */
10726 const char *zSchema, /* Which DB to serialize. ex: "main", "temp", ... */
10727 sqlite3_int64 *piSize, /* Write size of the DB here, if not NULL */
10728 unsigned int mFlags /* Zero or more SQLITE_SERIALIZE_* flags */
10729 );
10730
10731 /*
10732 ** CAPI3REF: Flags for sqlite3_serialize
10733 **
10734 ** Zero or more of the following constants can be OR-ed together for
10735 ** the F argument to [sqlite3_serialize(D,S,P,F)].
10736 **
10737 ** SQLITE_SERIALIZE_NOCOPY means that [sqlite3_serialize()] will return
10738 ** a pointer to contiguous in-memory database that it is currently using,
10739 ** without making a copy of the database. If SQLite is not currently using
10740 ** a contiguous in-memory database, then this option causes
10741 ** [sqlite3_serialize()] to return a NULL pointer. SQLite will only be
10742 ** using a contiguous in-memory database if it has been initialized by a
10743 ** prior call to [sqlite3_deserialize()].
10744 */
10745 #define SQLITE_SERIALIZE_NOCOPY 0x001 /* Do no memory allocations */
10746
10747 /*
10748 ** CAPI3REF: Deserialize a database
10749 **
10750 ** The sqlite3_deserialize(D,S,P,N,M,F) interface causes the
10751 ** [database connection] D to disconnect from database S and then
10752 ** reopen S as an in-memory database based on the serialization contained
10753 ** in P. The serialized database P is N bytes in size. M is the size of
10754 ** the buffer P, which might be larger than N. If M is larger than N, and
10755 ** the SQLITE_DESERIALIZE_READONLY bit is not set in F, then SQLite is
10756 ** permitted to add content to the in-memory database as long as the total
10757 ** size does not exceed M bytes.
10758 **
10759 ** If the SQLITE_DESERIALIZE_FREEONCLOSE bit is set in F, then SQLite will
10760 ** invoke sqlite3_free() on the serialization buffer when the database
10761 ** connection closes. If the SQLITE_DESERIALIZE_RESIZEABLE bit is set, then
10762 ** SQLite will try to increase the buffer size using sqlite3_realloc64()
10763 ** if writes on the database cause it to grow larger than M bytes.
10764 **
10765 ** Applications must not modify the buffer P or invalidate it before
10766 ** the database connection D is closed.
10767 **
10768 ** The sqlite3_deserialize() interface will fail with SQLITE_BUSY if the
10769 ** database is currently in a read transaction or is involved in a backup
10770 ** operation.
10771 **
10772 ** It is not possible to deserialized into the TEMP database. If the
10773 ** S argument to sqlite3_deserialize(D,S,P,N,M,F) is "temp" then the
10774 ** function returns SQLITE_ERROR.
10775 **
10776 ** The deserialized database should not be in [WAL mode]. If the database
10777 ** is in WAL mode, then any attempt to use the database file will result
10778 ** in an [SQLITE_CANTOPEN] error. The application can set the
10779 ** [file format version numbers] (bytes 18 and 19) of the input database P
10780 ** to 0x01 prior to invoking sqlite3_deserialize(D,S,P,N,M,F) to force the
10781 ** database file into rollback mode and work around this limitation.
10782 **
10783 ** If sqlite3_deserialize(D,S,P,N,M,F) fails for any reason and if the
10784 ** SQLITE_DESERIALIZE_FREEONCLOSE bit is set in argument F, then
10785 ** [sqlite3_free()] is invoked on argument P prior to returning.
10786 **
10787 ** This interface is omitted if SQLite is compiled with the
10788 ** [SQLITE_OMIT_DESERIALIZE] option.
10789 */
10790 SQLITE_API int sqlite3_deserialize(
10791 sqlite3 *db, /* The database connection */
10792 const char *zSchema, /* Which DB to reopen with the deserialization */
10793 unsigned char *pData, /* The serialized database content */
10794 sqlite3_int64 szDb, /* Number bytes in the deserialization */
10795 sqlite3_int64 szBuf, /* Total size of buffer pData[] */
10796 unsigned mFlags /* Zero or more SQLITE_DESERIALIZE_* flags */
10797 );
10798
10799 /*
10800 ** CAPI3REF: Flags for sqlite3_deserialize()
10801 **
10802 ** The following are allowed values for 6th argument (the F argument) to
10803 ** the [sqlite3_deserialize(D,S,P,N,M,F)] interface.
10804 **
10805 ** The SQLITE_DESERIALIZE_FREEONCLOSE means that the database serialization
10806 ** in the P argument is held in memory obtained from [sqlite3_malloc64()]
10807 ** and that SQLite should take ownership of this memory and automatically
10808 ** free it when it has finished using it. Without this flag, the caller
10809 ** is responsible for freeing any dynamically allocated memory.
10810 **
10811 ** The SQLITE_DESERIALIZE_RESIZEABLE flag means that SQLite is allowed to
10812 ** grow the size of the database using calls to [sqlite3_realloc64()]. This
10813 ** flag should only be used if SQLITE_DESERIALIZE_FREEONCLOSE is also used.
10814 ** Without this flag, the deserialized database cannot increase in size beyond
10815 ** the number of bytes specified by the M parameter.
10816 **
10817 ** The SQLITE_DESERIALIZE_READONLY flag means that the deserialized database
10818 ** should be treated as read-only.
10819 */
10820 #define SQLITE_DESERIALIZE_FREEONCLOSE 1 /* Call sqlite3_free() on close */
10821 #define SQLITE_DESERIALIZE_RESIZEABLE 2 /* Resize using sqlite3_realloc64() */
10822 #define SQLITE_DESERIALIZE_READONLY 4 /* Database is read-only */
10823
10824 /*
10825 ** Undo the hack that converts floating point types to integer for
10826 ** builds on processors without floating point support.
10827 */
10828 #ifdef SQLITE_OMIT_FLOATING_POINT
10829 # undef double
10830 #endif
10831
10832 #if defined(__wasi__)
10833 # undef SQLITE_WASI
10834 # define SQLITE_WASI 1
10835 # undef SQLITE_OMIT_WAL
10836 # define SQLITE_OMIT_WAL 1/* because it requires shared memory APIs */
10837 # ifndef SQLITE_OMIT_LOAD_EXTENSION
10838 # define SQLITE_OMIT_LOAD_EXTENSION
10839 # endif
10840 # ifndef SQLITE_THREADSAFE
10841 # define SQLITE_THREADSAFE 0
10842 # endif
10843 #endif
10844
10845 #ifdef __cplusplus
10846 } /* End of the 'extern "C"' block */
10847 #endif
10848 #endif /* SQLITE3_H */
10849
10850 /******** Begin file sqlite3rtree.h *********/
10851 /*
10852 ** 2010 August 30
10853 **
10854 ** The author disclaims copyright to this source code. In place of
10855 ** a legal notice, here is a blessing:
10856 **
10857 ** May you do good and not evil.
10858 ** May you find forgiveness for yourself and forgive others.
10859 ** May you share freely, never taking more than you give.
10860 **
10861 *************************************************************************
10862 */
10863
10864 #ifndef _SQLITE3RTREE_H_
10865 #define _SQLITE3RTREE_H_
10866
10867
10868 #ifdef __cplusplus
10869 extern "C" {
10870 #endif
10871
10872 typedef struct sqlite3_rtree_geometry sqlite3_rtree_geometry;
10873 typedef struct sqlite3_rtree_query_info sqlite3_rtree_query_info;
10874
10875 /* The double-precision datatype used by RTree depends on the
10876 ** SQLITE_RTREE_INT_ONLY compile-time option.
10877 */
10878 #ifdef SQLITE_RTREE_INT_ONLY
10879 typedef sqlite3_int64 sqlite3_rtree_dbl;
10880 #else
10881 typedef double sqlite3_rtree_dbl;
10882 #endif
10883
10884 /*
10885 ** Register a geometry callback named zGeom that can be used as part of an
10886 ** R-Tree geometry query as follows:
10887 **
10888 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zGeom(... params ...)
10889 */
10890 SQLITE_API int sqlite3_rtree_geometry_callback(
10891 sqlite3 *db,
10892 const char *zGeom,
10893 int (*xGeom)(sqlite3_rtree_geometry*, int, sqlite3_rtree_dbl*,int*),
10894 void *pContext
10895 );
10896
10897
10898 /*
10899 ** A pointer to a structure of the following type is passed as the first
10900 ** argument to callbacks registered using rtree_geometry_callback().
10901 */
10902 struct sqlite3_rtree_geometry {
10903 void *pContext; /* Copy of pContext passed to s_r_g_c() */
10904 int nParam; /* Size of array aParam[] */
10905 sqlite3_rtree_dbl *aParam; /* Parameters passed to SQL geom function */
10906 void *pUser; /* Callback implementation user data */
10907 void (*xDelUser)(void *); /* Called by SQLite to clean up pUser */
10908 };
10909
10910 /*
10911 ** Register a 2nd-generation geometry callback named zScore that can be
10912 ** used as part of an R-Tree geometry query as follows:
10913 **
10914 ** SELECT ... FROM <rtree> WHERE <rtree col> MATCH $zQueryFunc(... params ...)
10915 */
10916 SQLITE_API int sqlite3_rtree_query_callback(
10917 sqlite3 *db,
10918 const char *zQueryFunc,
10919 int (*xQueryFunc)(sqlite3_rtree_query_info*),
10920 void *pContext,
10921 void (*xDestructor)(void*)
10922 );
10923
10924
10925 /*
10926 ** A pointer to a structure of the following type is passed as the
10927 ** argument to scored geometry callback registered using
10928 ** sqlite3_rtree_query_callback().
10929 **
10930 ** Note that the first 5 fields of this structure are identical to
10931 ** sqlite3_rtree_geometry. This structure is a subclass of
10932 ** sqlite3_rtree_geometry.
10933 */
10934 struct sqlite3_rtree_query_info {
10935 void *pContext; /* pContext from when function registered */
10936 int nParam; /* Number of function parameters */
10937 sqlite3_rtree_dbl *aParam; /* value of function parameters */
10938 void *pUser; /* callback can use this, if desired */
10939 void (*xDelUser)(void*); /* function to free pUser */
10940 sqlite3_rtree_dbl *aCoord; /* Coordinates of node or entry to check */
10941 unsigned int *anQueue; /* Number of pending entries in the queue */
10942 int nCoord; /* Number of coordinates */
10943 int iLevel; /* Level of current node or entry */
10944 int mxLevel; /* The largest iLevel value in the tree */
10945 sqlite3_int64 iRowid; /* Rowid for current entry */
10946 sqlite3_rtree_dbl rParentScore; /* Score of parent node */
10947 int eParentWithin; /* Visibility of parent node */
10948 int eWithin; /* OUT: Visibility */
10949 sqlite3_rtree_dbl rScore; /* OUT: Write the score here */
10950 /* The following fields are only available in 3.8.11 and later */
10951 sqlite3_value **apSqlParam; /* Original SQL values of parameters */
10952 };
10953
10954 /*
10955 ** Allowed values for sqlite3_rtree_query.eWithin and .eParentWithin.
10956 */
10957 #define NOT_WITHIN 0 /* Object completely outside of query region */
10958 #define PARTLY_WITHIN 1 /* Object partially overlaps query region */
10959 #define FULLY_WITHIN 2 /* Object fully contained within query region */
10960
10961
10962 #ifdef __cplusplus
10963 } /* end of the 'extern "C"' block */
10964 #endif
10965
10966 #endif /* ifndef _SQLITE3RTREE_H_ */
10967
10968 /******** End of sqlite3rtree.h *********/
10969 /******** Begin file sqlite3session.h *********/
10970
10971 #if !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION)
10972 #define __SQLITESESSION_H_ 1
10973
10974 /*
10975 ** Make sure we can call this stuff from C++.
10976 */
10977 #ifdef __cplusplus
10978 extern "C" {
10979 #endif
10980
10981
10982 /*
10983 ** CAPI3REF: Session Object Handle
10984 **
10985 ** An instance of this object is a [session] that can be used to
10986 ** record changes to a database.
10987 */
10988 typedef struct sqlite3_session sqlite3_session;
10989
10990 /*
10991 ** CAPI3REF: Changeset Iterator Handle
10992 **
10993 ** An instance of this object acts as a cursor for iterating
10994 ** over the elements of a [changeset] or [patchset].
10995 */
10996 typedef struct sqlite3_changeset_iter sqlite3_changeset_iter;
10997
10998 /*
10999 ** CAPI3REF: Create A New Session Object
11000 ** CONSTRUCTOR: sqlite3_session
11001 **
11002 ** Create a new session object attached to database handle db. If successful,
11003 ** a pointer to the new object is written to *ppSession and SQLITE_OK is
11004 ** returned. If an error occurs, *ppSession is set to NULL and an SQLite
11005 ** error code (e.g. SQLITE_NOMEM) is returned.
11006 **
11007 ** It is possible to create multiple session objects attached to a single
11008 ** database handle.
11009 **
11010 ** Session objects created using this function should be deleted using the
11011 ** [sqlite3session_delete()] function before the database handle that they
11012 ** are attached to is itself closed. If the database handle is closed before
11013 ** the session object is deleted, then the results of calling any session
11014 ** module function, including [sqlite3session_delete()] on the session object
11015 ** are undefined.
11016 **
11017 ** Because the session module uses the [sqlite3_preupdate_hook()] API, it
11018 ** is not possible for an application to register a pre-update hook on a
11019 ** database handle that has one or more session objects attached. Nor is
11020 ** it possible to create a session object attached to a database handle for
11021 ** which a pre-update hook is already defined. The results of attempting
11022 ** either of these things are undefined.
11023 **
11024 ** The session object will be used to create changesets for tables in
11025 ** database zDb, where zDb is either "main", or "temp", or the name of an
11026 ** attached database. It is not an error if database zDb is not attached
11027 ** to the database when the session object is created.
11028 */
11029 SQLITE_API int sqlite3session_create(
11030 sqlite3 *db, /* Database handle */
11031 const char *zDb, /* Name of db (e.g. "main") */
11032 sqlite3_session **ppSession /* OUT: New session object */
11033 );
11034
11035 /*
11036 ** CAPI3REF: Delete A Session Object
11037 ** DESTRUCTOR: sqlite3_session
11038 **
11039 ** Delete a session object previously allocated using
11040 ** [sqlite3session_create()]. Once a session object has been deleted, the
11041 ** results of attempting to use pSession with any other session module
11042 ** function are undefined.
11043 **
11044 ** Session objects must be deleted before the database handle to which they
11045 ** are attached is closed. Refer to the documentation for
11046 ** [sqlite3session_create()] for details.
11047 */
11048 SQLITE_API void sqlite3session_delete(sqlite3_session *pSession);
11049
11050 /*
11051 ** CAPI3REF: Configure a Session Object
11052 ** METHOD: sqlite3_session
11053 **
11054 ** This method is used to configure a session object after it has been
11055 ** created. At present the only valid values for the second parameter are
11056 ** [SQLITE_SESSION_OBJCONFIG_SIZE] and [SQLITE_SESSION_OBJCONFIG_ROWID].
11057 **
11058 */
11059 SQLITE_API int sqlite3session_object_config(sqlite3_session*, int op, void *pArg);
11060
11061 /*
11062 ** CAPI3REF: Options for sqlite3session_object_config
11063 **
11064 ** The following values may passed as the the 2nd parameter to
11065 ** sqlite3session_object_config().
11066 **
11067 ** <dt>SQLITE_SESSION_OBJCONFIG_SIZE <dd>
11068 ** This option is used to set, clear or query the flag that enables
11069 ** the [sqlite3session_changeset_size()] API. Because it imposes some
11070 ** computational overhead, this API is disabled by default. Argument
11071 ** pArg must point to a value of type (int). If the value is initially
11072 ** 0, then the sqlite3session_changeset_size() API is disabled. If it
11073 ** is greater than 0, then the same API is enabled. Or, if the initial
11074 ** value is less than zero, no change is made. In all cases the (int)
11075 ** variable is set to 1 if the sqlite3session_changeset_size() API is
11076 ** enabled following the current call, or 0 otherwise.
11077 **
11078 ** It is an error (SQLITE_MISUSE) to attempt to modify this setting after
11079 ** the first table has been attached to the session object.
11080 **
11081 ** <dt>SQLITE_SESSION_OBJCONFIG_ROWID <dd>
11082 ** This option is used to set, clear or query the flag that enables
11083 ** collection of data for tables with no explicit PRIMARY KEY.
11084 **
11085 ** Normally, tables with no explicit PRIMARY KEY are simply ignored
11086 ** by the sessions module. However, if this flag is set, it behaves
11087 ** as if such tables have a column "_rowid_ INTEGER PRIMARY KEY" inserted
11088 ** as their leftmost columns.
11089 **
11090 ** It is an error (SQLITE_MISUSE) to attempt to modify this setting after
11091 ** the first table has been attached to the session object.
11092 */
11093 #define SQLITE_SESSION_OBJCONFIG_SIZE 1
11094 #define SQLITE_SESSION_OBJCONFIG_ROWID 2
11095
11096 /*
11097 ** CAPI3REF: Enable Or Disable A Session Object
11098 ** METHOD: sqlite3_session
11099 **
11100 ** Enable or disable the recording of changes by a session object. When
11101 ** enabled, a session object records changes made to the database. When
11102 ** disabled - it does not. A newly created session object is enabled.
11103 ** Refer to the documentation for [sqlite3session_changeset()] for further
11104 ** details regarding how enabling and disabling a session object affects
11105 ** the eventual changesets.
11106 **
11107 ** Passing zero to this function disables the session. Passing a value
11108 ** greater than zero enables it. Passing a value less than zero is a
11109 ** no-op, and may be used to query the current state of the session.
11110 **
11111 ** The return value indicates the final state of the session object: 0 if
11112 ** the session is disabled, or 1 if it is enabled.
11113 */
11114 SQLITE_API int sqlite3session_enable(sqlite3_session *pSession, int bEnable);
11115
11116 /*
11117 ** CAPI3REF: Set Or Clear the Indirect Change Flag
11118 ** METHOD: sqlite3_session
11119 **
11120 ** Each change recorded by a session object is marked as either direct or
11121 ** indirect. A change is marked as indirect if either:
11122 **
11123 ** <ul>
11124 ** <li> The session object "indirect" flag is set when the change is
11125 ** made, or
11126 ** <li> The change is made by an SQL trigger or foreign key action
11127 ** instead of directly as a result of a users SQL statement.
11128 ** </ul>
11129 **
11130 ** If a single row is affected by more than one operation within a session,
11131 ** then the change is considered indirect if all operations meet the criteria
11132 ** for an indirect change above, or direct otherwise.
11133 **
11134 ** This function is used to set, clear or query the session object indirect
11135 ** flag. If the second argument passed to this function is zero, then the
11136 ** indirect flag is cleared. If it is greater than zero, the indirect flag
11137 ** is set. Passing a value less than zero does not modify the current value
11138 ** of the indirect flag, and may be used to query the current state of the
11139 ** indirect flag for the specified session object.
11140 **
11141 ** The return value indicates the final state of the indirect flag: 0 if
11142 ** it is clear, or 1 if it is set.
11143 */
11144 SQLITE_API int sqlite3session_indirect(sqlite3_session *pSession, int bIndirect);
11145
11146 /*
11147 ** CAPI3REF: Attach A Table To A Session Object
11148 ** METHOD: sqlite3_session
11149 **
11150 ** If argument zTab is not NULL, then it is the name of a table to attach
11151 ** to the session object passed as the first argument. All subsequent changes
11152 ** made to the table while the session object is enabled will be recorded. See
11153 ** documentation for [sqlite3session_changeset()] for further details.
11154 **
11155 ** Or, if argument zTab is NULL, then changes are recorded for all tables
11156 ** in the database. If additional tables are added to the database (by
11157 ** executing "CREATE TABLE" statements) after this call is made, changes for
11158 ** the new tables are also recorded.
11159 **
11160 ** Changes can only be recorded for tables that have a PRIMARY KEY explicitly
11161 ** defined as part of their CREATE TABLE statement. It does not matter if the
11162 ** PRIMARY KEY is an "INTEGER PRIMARY KEY" (rowid alias) or not. The PRIMARY
11163 ** KEY may consist of a single column, or may be a composite key.
11164 **
11165 ** It is not an error if the named table does not exist in the database. Nor
11166 ** is it an error if the named table does not have a PRIMARY KEY. However,
11167 ** no changes will be recorded in either of these scenarios.
11168 **
11169 ** Changes are not recorded for individual rows that have NULL values stored
11170 ** in one or more of their PRIMARY KEY columns.
11171 **
11172 ** SQLITE_OK is returned if the call completes without error. Or, if an error
11173 ** occurs, an SQLite error code (e.g. SQLITE_NOMEM) is returned.
11174 **
11175 ** <h3>Special sqlite_stat1 Handling</h3>
11176 **
11177 ** As of SQLite version 3.22.0, the "sqlite_stat1" table is an exception to
11178 ** some of the rules above. In SQLite, the schema of sqlite_stat1 is:
11179 ** <pre>
11180 ** &nbsp; CREATE TABLE sqlite_stat1(tbl,idx,stat)
11181 ** </pre>
11182 **
11183 ** Even though sqlite_stat1 does not have a PRIMARY KEY, changes are
11184 ** recorded for it as if the PRIMARY KEY is (tbl,idx). Additionally, changes
11185 ** are recorded for rows for which (idx IS NULL) is true. However, for such
11186 ** rows a zero-length blob (SQL value X'') is stored in the changeset or
11187 ** patchset instead of a NULL value. This allows such changesets to be
11188 ** manipulated by legacy implementations of sqlite3changeset_invert(),
11189 ** concat() and similar.
11190 **
11191 ** The sqlite3changeset_apply() function automatically converts the
11192 ** zero-length blob back to a NULL value when updating the sqlite_stat1
11193 ** table. However, if the application calls sqlite3changeset_new(),
11194 ** sqlite3changeset_old() or sqlite3changeset_conflict on a changeset
11195 ** iterator directly (including on a changeset iterator passed to a
11196 ** conflict-handler callback) then the X'' value is returned. The application
11197 ** must translate X'' to NULL itself if required.
11198 **
11199 ** Legacy (older than 3.22.0) versions of the sessions module cannot capture
11200 ** changes made to the sqlite_stat1 table. Legacy versions of the
11201 ** sqlite3changeset_apply() function silently ignore any modifications to the
11202 ** sqlite_stat1 table that are part of a changeset or patchset.
11203 */
11204 SQLITE_API int sqlite3session_attach(
11205 sqlite3_session *pSession, /* Session object */
11206 const char *zTab /* Table name */
11207 );
11208
11209 /*
11210 ** CAPI3REF: Set a table filter on a Session Object.
11211 ** METHOD: sqlite3_session
11212 **
11213 ** The second argument (xFilter) is the "filter callback". For changes to rows
11214 ** in tables that are not attached to the Session object, the filter is called
11215 ** to determine whether changes to the table's rows should be tracked or not.
11216 ** If xFilter returns 0, changes are not tracked. Note that once a table is
11217 ** attached, xFilter will not be called again.
11218 */
11219 SQLITE_API void sqlite3session_table_filter(
11220 sqlite3_session *pSession, /* Session object */
11221 int(*xFilter)(
11222 void *pCtx, /* Copy of third arg to _filter_table() */
11223 const char *zTab /* Table name */
11224 ),
11225 void *pCtx /* First argument passed to xFilter */
11226 );
11227
11228 /*
11229 ** CAPI3REF: Generate A Changeset From A Session Object
11230 ** METHOD: sqlite3_session
11231 **
11232 ** Obtain a changeset containing changes to the tables attached to the
11233 ** session object passed as the first argument. If successful,
11234 ** set *ppChangeset to point to a buffer containing the changeset
11235 ** and *pnChangeset to the size of the changeset in bytes before returning
11236 ** SQLITE_OK. If an error occurs, set both *ppChangeset and *pnChangeset to
11237 ** zero and return an SQLite error code.
11238 **
11239 ** A changeset consists of zero or more INSERT, UPDATE and/or DELETE changes,
11240 ** each representing a change to a single row of an attached table. An INSERT
11241 ** change contains the values of each field of a new database row. A DELETE
11242 ** contains the original values of each field of a deleted database row. An
11243 ** UPDATE change contains the original values of each field of an updated
11244 ** database row along with the updated values for each updated non-primary-key
11245 ** column. It is not possible for an UPDATE change to represent a change that
11246 ** modifies the values of primary key columns. If such a change is made, it
11247 ** is represented in a changeset as a DELETE followed by an INSERT.
11248 **
11249 ** Changes are not recorded for rows that have NULL values stored in one or
11250 ** more of their PRIMARY KEY columns. If such a row is inserted or deleted,
11251 ** no corresponding change is present in the changesets returned by this
11252 ** function. If an existing row with one or more NULL values stored in
11253 ** PRIMARY KEY columns is updated so that all PRIMARY KEY columns are non-NULL,
11254 ** only an INSERT is appears in the changeset. Similarly, if an existing row
11255 ** with non-NULL PRIMARY KEY values is updated so that one or more of its
11256 ** PRIMARY KEY columns are set to NULL, the resulting changeset contains a
11257 ** DELETE change only.
11258 **
11259 ** The contents of a changeset may be traversed using an iterator created
11260 ** using the [sqlite3changeset_start()] API. A changeset may be applied to
11261 ** a database with a compatible schema using the [sqlite3changeset_apply()]
11262 ** API.
11263 **
11264 ** Within a changeset generated by this function, all changes related to a
11265 ** single table are grouped together. In other words, when iterating through
11266 ** a changeset or when applying a changeset to a database, all changes related
11267 ** to a single table are processed before moving on to the next table. Tables
11268 ** are sorted in the same order in which they were attached (or auto-attached)
11269 ** to the sqlite3_session object. The order in which the changes related to
11270 ** a single table are stored is undefined.
11271 **
11272 ** Following a successful call to this function, it is the responsibility of
11273 ** the caller to eventually free the buffer that *ppChangeset points to using
11274 ** [sqlite3_free()].
11275 **
11276 ** <h3>Changeset Generation</h3>
11277 **
11278 ** Once a table has been attached to a session object, the session object
11279 ** records the primary key values of all new rows inserted into the table.
11280 ** It also records the original primary key and other column values of any
11281 ** deleted or updated rows. For each unique primary key value, data is only
11282 ** recorded once - the first time a row with said primary key is inserted,
11283 ** updated or deleted in the lifetime of the session.
11284 **
11285 ** There is one exception to the previous paragraph: when a row is inserted,
11286 ** updated or deleted, if one or more of its primary key columns contain a
11287 ** NULL value, no record of the change is made.
11288 **
11289 ** The session object therefore accumulates two types of records - those
11290 ** that consist of primary key values only (created when the user inserts
11291 ** a new record) and those that consist of the primary key values and the
11292 ** original values of other table columns (created when the users deletes
11293 ** or updates a record).
11294 **
11295 ** When this function is called, the requested changeset is created using
11296 ** both the accumulated records and the current contents of the database
11297 ** file. Specifically:
11298 **
11299 ** <ul>
11300 ** <li> For each record generated by an insert, the database is queried
11301 ** for a row with a matching primary key. If one is found, an INSERT
11302 ** change is added to the changeset. If no such row is found, no change
11303 ** is added to the changeset.
11304 **
11305 ** <li> For each record generated by an update or delete, the database is
11306 ** queried for a row with a matching primary key. If such a row is
11307 ** found and one or more of the non-primary key fields have been
11308 ** modified from their original values, an UPDATE change is added to
11309 ** the changeset. Or, if no such row is found in the table, a DELETE
11310 ** change is added to the changeset. If there is a row with a matching
11311 ** primary key in the database, but all fields contain their original
11312 ** values, no change is added to the changeset.
11313 ** </ul>
11314 **
11315 ** This means, amongst other things, that if a row is inserted and then later
11316 ** deleted while a session object is active, neither the insert nor the delete
11317 ** will be present in the changeset. Or if a row is deleted and then later a
11318 ** row with the same primary key values inserted while a session object is
11319 ** active, the resulting changeset will contain an UPDATE change instead of
11320 ** a DELETE and an INSERT.
11321 **
11322 ** When a session object is disabled (see the [sqlite3session_enable()] API),
11323 ** it does not accumulate records when rows are inserted, updated or deleted.
11324 ** This may appear to have some counter-intuitive effects if a single row
11325 ** is written to more than once during a session. For example, if a row
11326 ** is inserted while a session object is enabled, then later deleted while
11327 ** the same session object is disabled, no INSERT record will appear in the
11328 ** changeset, even though the delete took place while the session was disabled.
11329 ** Or, if one field of a row is updated while a session is disabled, and
11330 ** another field of the same row is updated while the session is enabled, the
11331 ** resulting changeset will contain an UPDATE change that updates both fields.
11332 */
11333 SQLITE_API int sqlite3session_changeset(
11334 sqlite3_session *pSession, /* Session object */
11335 int *pnChangeset, /* OUT: Size of buffer at *ppChangeset */
11336 void **ppChangeset /* OUT: Buffer containing changeset */
11337 );
11338
11339 /*
11340 ** CAPI3REF: Return An Upper-limit For The Size Of The Changeset
11341 ** METHOD: sqlite3_session
11342 **
11343 ** By default, this function always returns 0. For it to return
11344 ** a useful result, the sqlite3_session object must have been configured
11345 ** to enable this API using sqlite3session_object_config() with the
11346 ** SQLITE_SESSION_OBJCONFIG_SIZE verb.
11347 **
11348 ** When enabled, this function returns an upper limit, in bytes, for the size
11349 ** of the changeset that might be produced if sqlite3session_changeset() were
11350 ** called. The final changeset size might be equal to or smaller than the
11351 ** size in bytes returned by this function.
11352 */
11353 SQLITE_API sqlite3_int64 sqlite3session_changeset_size(sqlite3_session *pSession);
11354
11355 /*
11356 ** CAPI3REF: Load The Difference Between Tables Into A Session
11357 ** METHOD: sqlite3_session
11358 **
11359 ** If it is not already attached to the session object passed as the first
11360 ** argument, this function attaches table zTbl in the same manner as the
11361 ** [sqlite3session_attach()] function. If zTbl does not exist, or if it
11362 ** does not have a primary key, this function is a no-op (but does not return
11363 ** an error).
11364 **
11365 ** Argument zFromDb must be the name of a database ("main", "temp" etc.)
11366 ** attached to the same database handle as the session object that contains
11367 ** a table compatible with the table attached to the session by this function.
11368 ** A table is considered compatible if it:
11369 **
11370 ** <ul>
11371 ** <li> Has the same name,
11372 ** <li> Has the same set of columns declared in the same order, and
11373 ** <li> Has the same PRIMARY KEY definition.
11374 ** </ul>
11375 **
11376 ** If the tables are not compatible, SQLITE_SCHEMA is returned. If the tables
11377 ** are compatible but do not have any PRIMARY KEY columns, it is not an error
11378 ** but no changes are added to the session object. As with other session
11379 ** APIs, tables without PRIMARY KEYs are simply ignored.
11380 **
11381 ** This function adds a set of changes to the session object that could be
11382 ** used to update the table in database zFrom (call this the "from-table")
11383 ** so that its content is the same as the table attached to the session
11384 ** object (call this the "to-table"). Specifically:
11385 **
11386 ** <ul>
11387 ** <li> For each row (primary key) that exists in the to-table but not in
11388 ** the from-table, an INSERT record is added to the session object.
11389 **
11390 ** <li> For each row (primary key) that exists in the to-table but not in
11391 ** the from-table, a DELETE record is added to the session object.
11392 **
11393 ** <li> For each row (primary key) that exists in both tables, but features
11394 ** different non-PK values in each, an UPDATE record is added to the
11395 ** session.
11396 ** </ul>
11397 **
11398 ** To clarify, if this function is called and then a changeset constructed
11399 ** using [sqlite3session_changeset()], then after applying that changeset to
11400 ** database zFrom the contents of the two compatible tables would be
11401 ** identical.
11402 **
11403 ** It an error if database zFrom does not exist or does not contain the
11404 ** required compatible table.
11405 **
11406 ** If the operation is successful, SQLITE_OK is returned. Otherwise, an SQLite
11407 ** error code. In this case, if argument pzErrMsg is not NULL, *pzErrMsg
11408 ** may be set to point to a buffer containing an English language error
11409 ** message. It is the responsibility of the caller to free this buffer using
11410 ** sqlite3_free().
11411 */
11412 SQLITE_API int sqlite3session_diff(
11413 sqlite3_session *pSession,
11414 const char *zFromDb,
11415 const char *zTbl,
11416 char **pzErrMsg
11417 );
11418
11419
11420 /*
11421 ** CAPI3REF: Generate A Patchset From A Session Object
11422 ** METHOD: sqlite3_session
11423 **
11424 ** The differences between a patchset and a changeset are that:
11425 **
11426 ** <ul>
11427 ** <li> DELETE records consist of the primary key fields only. The
11428 ** original values of other fields are omitted.
11429 ** <li> The original values of any modified fields are omitted from
11430 ** UPDATE records.
11431 ** </ul>
11432 **
11433 ** A patchset blob may be used with up to date versions of all
11434 ** sqlite3changeset_xxx API functions except for sqlite3changeset_invert(),
11435 ** which returns SQLITE_CORRUPT if it is passed a patchset. Similarly,
11436 ** attempting to use a patchset blob with old versions of the
11437 ** sqlite3changeset_xxx APIs also provokes an SQLITE_CORRUPT error.
11438 **
11439 ** Because the non-primary key "old.*" fields are omitted, no
11440 ** SQLITE_CHANGESET_DATA conflicts can be detected or reported if a patchset
11441 ** is passed to the sqlite3changeset_apply() API. Other conflict types work
11442 ** in the same way as for changesets.
11443 **
11444 ** Changes within a patchset are ordered in the same way as for changesets
11445 ** generated by the sqlite3session_changeset() function (i.e. all changes for
11446 ** a single table are grouped together, tables appear in the order in which
11447 ** they were attached to the session object).
11448 */
11449 SQLITE_API int sqlite3session_patchset(
11450 sqlite3_session *pSession, /* Session object */
11451 int *pnPatchset, /* OUT: Size of buffer at *ppPatchset */
11452 void **ppPatchset /* OUT: Buffer containing patchset */
11453 );
11454
11455 /*
11456 ** CAPI3REF: Test if a changeset has recorded any changes.
11457 **
11458 ** Return non-zero if no changes to attached tables have been recorded by
11459 ** the session object passed as the first argument. Otherwise, if one or
11460 ** more changes have been recorded, return zero.
11461 **
11462 ** Even if this function returns zero, it is possible that calling
11463 ** [sqlite3session_changeset()] on the session handle may still return a
11464 ** changeset that contains no changes. This can happen when a row in
11465 ** an attached table is modified and then later on the original values
11466 ** are restored. However, if this function returns non-zero, then it is
11467 ** guaranteed that a call to sqlite3session_changeset() will return a
11468 ** changeset containing zero changes.
11469 */
11470 SQLITE_API int sqlite3session_isempty(sqlite3_session *pSession);
11471
11472 /*
11473 ** CAPI3REF: Query for the amount of heap memory used by a session object.
11474 **
11475 ** This API returns the total amount of heap memory in bytes currently
11476 ** used by the session object passed as the only argument.
11477 */
11478 SQLITE_API sqlite3_int64 sqlite3session_memory_used(sqlite3_session *pSession);
11479
11480 /*
11481 ** CAPI3REF: Create An Iterator To Traverse A Changeset
11482 ** CONSTRUCTOR: sqlite3_changeset_iter
11483 **
11484 ** Create an iterator used to iterate through the contents of a changeset.
11485 ** If successful, *pp is set to point to the iterator handle and SQLITE_OK
11486 ** is returned. Otherwise, if an error occurs, *pp is set to zero and an
11487 ** SQLite error code is returned.
11488 **
11489 ** The following functions can be used to advance and query a changeset
11490 ** iterator created by this function:
11491 **
11492 ** <ul>
11493 ** <li> [sqlite3changeset_next()]
11494 ** <li> [sqlite3changeset_op()]
11495 ** <li> [sqlite3changeset_new()]
11496 ** <li> [sqlite3changeset_old()]
11497 ** </ul>
11498 **
11499 ** It is the responsibility of the caller to eventually destroy the iterator
11500 ** by passing it to [sqlite3changeset_finalize()]. The buffer containing the
11501 ** changeset (pChangeset) must remain valid until after the iterator is
11502 ** destroyed.
11503 **
11504 ** Assuming the changeset blob was created by one of the
11505 ** [sqlite3session_changeset()], [sqlite3changeset_concat()] or
11506 ** [sqlite3changeset_invert()] functions, all changes within the changeset
11507 ** that apply to a single table are grouped together. This means that when
11508 ** an application iterates through a changeset using an iterator created by
11509 ** this function, all changes that relate to a single table are visited
11510 ** consecutively. There is no chance that the iterator will visit a change
11511 ** the applies to table X, then one for table Y, and then later on visit
11512 ** another change for table X.
11513 **
11514 ** The behavior of sqlite3changeset_start_v2() and its streaming equivalent
11515 ** may be modified by passing a combination of
11516 ** [SQLITE_CHANGESETSTART_INVERT | supported flags] as the 4th parameter.
11517 **
11518 ** Note that the sqlite3changeset_start_v2() API is still <b>experimental</b>
11519 ** and therefore subject to change.
11520 */
11521 SQLITE_API int sqlite3changeset_start(
11522 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */
11523 int nChangeset, /* Size of changeset blob in bytes */
11524 void *pChangeset /* Pointer to blob containing changeset */
11525 );
11526 SQLITE_API int sqlite3changeset_start_v2(
11527 sqlite3_changeset_iter **pp, /* OUT: New changeset iterator handle */
11528 int nChangeset, /* Size of changeset blob in bytes */
11529 void *pChangeset, /* Pointer to blob containing changeset */
11530 int flags /* SESSION_CHANGESETSTART_* flags */
11531 );
11532
11533 /*
11534 ** CAPI3REF: Flags for sqlite3changeset_start_v2
11535 **
11536 ** The following flags may passed via the 4th parameter to
11537 ** [sqlite3changeset_start_v2] and [sqlite3changeset_start_v2_strm]:
11538 **
11539 ** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd>
11540 ** Invert the changeset while iterating through it. This is equivalent to
11541 ** inverting a changeset using sqlite3changeset_invert() before applying it.
11542 ** It is an error to specify this flag with a patchset.
11543 */
11544 #define SQLITE_CHANGESETSTART_INVERT 0x0002
11545
11546
11547 /*
11548 ** CAPI3REF: Advance A Changeset Iterator
11549 ** METHOD: sqlite3_changeset_iter
11550 **
11551 ** This function may only be used with iterators created by the function
11552 ** [sqlite3changeset_start()]. If it is called on an iterator passed to
11553 ** a conflict-handler callback by [sqlite3changeset_apply()], SQLITE_MISUSE
11554 ** is returned and the call has no effect.
11555 **
11556 ** Immediately after an iterator is created by sqlite3changeset_start(), it
11557 ** does not point to any change in the changeset. Assuming the changeset
11558 ** is not empty, the first call to this function advances the iterator to
11559 ** point to the first change in the changeset. Each subsequent call advances
11560 ** the iterator to point to the next change in the changeset (if any). If
11561 ** no error occurs and the iterator points to a valid change after a call
11562 ** to sqlite3changeset_next() has advanced it, SQLITE_ROW is returned.
11563 ** Otherwise, if all changes in the changeset have already been visited,
11564 ** SQLITE_DONE is returned.
11565 **
11566 ** If an error occurs, an SQLite error code is returned. Possible error
11567 ** codes include SQLITE_CORRUPT (if the changeset buffer is corrupt) or
11568 ** SQLITE_NOMEM.
11569 */
11570 SQLITE_API int sqlite3changeset_next(sqlite3_changeset_iter *pIter);
11571
11572 /*
11573 ** CAPI3REF: Obtain The Current Operation From A Changeset Iterator
11574 ** METHOD: sqlite3_changeset_iter
11575 **
11576 ** The pIter argument passed to this function may either be an iterator
11577 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
11578 ** created by [sqlite3changeset_start()]. In the latter case, the most recent
11579 ** call to [sqlite3changeset_next()] must have returned [SQLITE_ROW]. If this
11580 ** is not the case, this function returns [SQLITE_MISUSE].
11581 **
11582 ** Arguments pOp, pnCol and pzTab may not be NULL. Upon return, three
11583 ** outputs are set through these pointers:
11584 **
11585 ** *pOp is set to one of [SQLITE_INSERT], [SQLITE_DELETE] or [SQLITE_UPDATE],
11586 ** depending on the type of change that the iterator currently points to;
11587 **
11588 ** *pnCol is set to the number of columns in the table affected by the change; and
11589 **
11590 ** *pzTab is set to point to a nul-terminated utf-8 encoded string containing
11591 ** the name of the table affected by the current change. The buffer remains
11592 ** valid until either sqlite3changeset_next() is called on the iterator
11593 ** or until the conflict-handler function returns.
11594 **
11595 ** If pbIndirect is not NULL, then *pbIndirect is set to true (1) if the change
11596 ** is an indirect change, or false (0) otherwise. See the documentation for
11597 ** [sqlite3session_indirect()] for a description of direct and indirect
11598 ** changes.
11599 **
11600 ** If no error occurs, SQLITE_OK is returned. If an error does occur, an
11601 ** SQLite error code is returned. The values of the output variables may not
11602 ** be trusted in this case.
11603 */
11604 SQLITE_API int sqlite3changeset_op(
11605 sqlite3_changeset_iter *pIter, /* Iterator object */
11606 const char **pzTab, /* OUT: Pointer to table name */
11607 int *pnCol, /* OUT: Number of columns in table */
11608 int *pOp, /* OUT: SQLITE_INSERT, DELETE or UPDATE */
11609 int *pbIndirect /* OUT: True for an 'indirect' change */
11610 );
11611
11612 /*
11613 ** CAPI3REF: Obtain The Primary Key Definition Of A Table
11614 ** METHOD: sqlite3_changeset_iter
11615 **
11616 ** For each modified table, a changeset includes the following:
11617 **
11618 ** <ul>
11619 ** <li> The number of columns in the table, and
11620 ** <li> Which of those columns make up the tables PRIMARY KEY.
11621 ** </ul>
11622 **
11623 ** This function is used to find which columns comprise the PRIMARY KEY of
11624 ** the table modified by the change that iterator pIter currently points to.
11625 ** If successful, *pabPK is set to point to an array of nCol entries, where
11626 ** nCol is the number of columns in the table. Elements of *pabPK are set to
11627 ** 0x01 if the corresponding column is part of the tables primary key, or
11628 ** 0x00 if it is not.
11629 **
11630 ** If argument pnCol is not NULL, then *pnCol is set to the number of columns
11631 ** in the table.
11632 **
11633 ** If this function is called when the iterator does not point to a valid
11634 ** entry, SQLITE_MISUSE is returned and the output variables zeroed. Otherwise,
11635 ** SQLITE_OK is returned and the output variables populated as described
11636 ** above.
11637 */
11638 SQLITE_API int sqlite3changeset_pk(
11639 sqlite3_changeset_iter *pIter, /* Iterator object */
11640 unsigned char **pabPK, /* OUT: Array of boolean - true for PK cols */
11641 int *pnCol /* OUT: Number of entries in output array */
11642 );
11643
11644 /*
11645 ** CAPI3REF: Obtain old.* Values From A Changeset Iterator
11646 ** METHOD: sqlite3_changeset_iter
11647 **
11648 ** The pIter argument passed to this function may either be an iterator
11649 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
11650 ** created by [sqlite3changeset_start()]. In the latter case, the most recent
11651 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW.
11652 ** Furthermore, it may only be called if the type of change that the iterator
11653 ** currently points to is either [SQLITE_DELETE] or [SQLITE_UPDATE]. Otherwise,
11654 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
11655 **
11656 ** Argument iVal must be greater than or equal to 0, and less than the number
11657 ** of columns in the table affected by the current change. Otherwise,
11658 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
11659 **
11660 ** If successful, this function sets *ppValue to point to a protected
11661 ** sqlite3_value object containing the iVal'th value from the vector of
11662 ** original row values stored as part of the UPDATE or DELETE change and
11663 ** returns SQLITE_OK. The name of the function comes from the fact that this
11664 ** is similar to the "old.*" columns available to update or delete triggers.
11665 **
11666 ** If some other error occurs (e.g. an OOM condition), an SQLite error code
11667 ** is returned and *ppValue is set to NULL.
11668 */
11669 SQLITE_API int sqlite3changeset_old(
11670 sqlite3_changeset_iter *pIter, /* Changeset iterator */
11671 int iVal, /* Column number */
11672 sqlite3_value **ppValue /* OUT: Old value (or NULL pointer) */
11673 );
11674
11675 /*
11676 ** CAPI3REF: Obtain new.* Values From A Changeset Iterator
11677 ** METHOD: sqlite3_changeset_iter
11678 **
11679 ** The pIter argument passed to this function may either be an iterator
11680 ** passed to a conflict-handler by [sqlite3changeset_apply()], or an iterator
11681 ** created by [sqlite3changeset_start()]. In the latter case, the most recent
11682 ** call to [sqlite3changeset_next()] must have returned SQLITE_ROW.
11683 ** Furthermore, it may only be called if the type of change that the iterator
11684 ** currently points to is either [SQLITE_UPDATE] or [SQLITE_INSERT]. Otherwise,
11685 ** this function returns [SQLITE_MISUSE] and sets *ppValue to NULL.
11686 **
11687 ** Argument iVal must be greater than or equal to 0, and less than the number
11688 ** of columns in the table affected by the current change. Otherwise,
11689 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
11690 **
11691 ** If successful, this function sets *ppValue to point to a protected
11692 ** sqlite3_value object containing the iVal'th value from the vector of
11693 ** new row values stored as part of the UPDATE or INSERT change and
11694 ** returns SQLITE_OK. If the change is an UPDATE and does not include
11695 ** a new value for the requested column, *ppValue is set to NULL and
11696 ** SQLITE_OK returned. The name of the function comes from the fact that
11697 ** this is similar to the "new.*" columns available to update or delete
11698 ** triggers.
11699 **
11700 ** If some other error occurs (e.g. an OOM condition), an SQLite error code
11701 ** is returned and *ppValue is set to NULL.
11702 */
11703 SQLITE_API int sqlite3changeset_new(
11704 sqlite3_changeset_iter *pIter, /* Changeset iterator */
11705 int iVal, /* Column number */
11706 sqlite3_value **ppValue /* OUT: New value (or NULL pointer) */
11707 );
11708
11709 /*
11710 ** CAPI3REF: Obtain Conflicting Row Values From A Changeset Iterator
11711 ** METHOD: sqlite3_changeset_iter
11712 **
11713 ** This function should only be used with iterator objects passed to a
11714 ** conflict-handler callback by [sqlite3changeset_apply()] with either
11715 ** [SQLITE_CHANGESET_DATA] or [SQLITE_CHANGESET_CONFLICT]. If this function
11716 ** is called on any other iterator, [SQLITE_MISUSE] is returned and *ppValue
11717 ** is set to NULL.
11718 **
11719 ** Argument iVal must be greater than or equal to 0, and less than the number
11720 ** of columns in the table affected by the current change. Otherwise,
11721 ** [SQLITE_RANGE] is returned and *ppValue is set to NULL.
11722 **
11723 ** If successful, this function sets *ppValue to point to a protected
11724 ** sqlite3_value object containing the iVal'th value from the
11725 ** "conflicting row" associated with the current conflict-handler callback
11726 ** and returns SQLITE_OK.
11727 **
11728 ** If some other error occurs (e.g. an OOM condition), an SQLite error code
11729 ** is returned and *ppValue is set to NULL.
11730 */
11731 SQLITE_API int sqlite3changeset_conflict(
11732 sqlite3_changeset_iter *pIter, /* Changeset iterator */
11733 int iVal, /* Column number */
11734 sqlite3_value **ppValue /* OUT: Value from conflicting row */
11735 );
11736
11737 /*
11738 ** CAPI3REF: Determine The Number Of Foreign Key Constraint Violations
11739 ** METHOD: sqlite3_changeset_iter
11740 **
11741 ** This function may only be called with an iterator passed to an
11742 ** SQLITE_CHANGESET_FOREIGN_KEY conflict handler callback. In this case
11743 ** it sets the output variable to the total number of known foreign key
11744 ** violations in the destination database and returns SQLITE_OK.
11745 **
11746 ** In all other cases this function returns SQLITE_MISUSE.
11747 */
11748 SQLITE_API int sqlite3changeset_fk_conflicts(
11749 sqlite3_changeset_iter *pIter, /* Changeset iterator */
11750 int *pnOut /* OUT: Number of FK violations */
11751 );
11752
11753
11754 /*
11755 ** CAPI3REF: Finalize A Changeset Iterator
11756 ** METHOD: sqlite3_changeset_iter
11757 **
11758 ** This function is used to finalize an iterator allocated with
11759 ** [sqlite3changeset_start()].
11760 **
11761 ** This function should only be called on iterators created using the
11762 ** [sqlite3changeset_start()] function. If an application calls this
11763 ** function with an iterator passed to a conflict-handler by
11764 ** [sqlite3changeset_apply()], [SQLITE_MISUSE] is immediately returned and the
11765 ** call has no effect.
11766 **
11767 ** If an error was encountered within a call to an sqlite3changeset_xxx()
11768 ** function (for example an [SQLITE_CORRUPT] in [sqlite3changeset_next()] or an
11769 ** [SQLITE_NOMEM] in [sqlite3changeset_new()]) then an error code corresponding
11770 ** to that error is returned by this function. Otherwise, SQLITE_OK is
11771 ** returned. This is to allow the following pattern (pseudo-code):
11772 **
11773 ** <pre>
11774 ** sqlite3changeset_start();
11775 ** while( SQLITE_ROW==sqlite3changeset_next() ){
11776 ** // Do something with change.
11777 ** }
11778 ** rc = sqlite3changeset_finalize();
11779 ** if( rc!=SQLITE_OK ){
11780 ** // An error has occurred
11781 ** }
11782 ** </pre>
11783 */
11784 SQLITE_API int sqlite3changeset_finalize(sqlite3_changeset_iter *pIter);
11785
11786 /*
11787 ** CAPI3REF: Invert A Changeset
11788 **
11789 ** This function is used to "invert" a changeset object. Applying an inverted
11790 ** changeset to a database reverses the effects of applying the uninverted
11791 ** changeset. Specifically:
11792 **
11793 ** <ul>
11794 ** <li> Each DELETE change is changed to an INSERT, and
11795 ** <li> Each INSERT change is changed to a DELETE, and
11796 ** <li> For each UPDATE change, the old.* and new.* values are exchanged.
11797 ** </ul>
11798 **
11799 ** This function does not change the order in which changes appear within
11800 ** the changeset. It merely reverses the sense of each individual change.
11801 **
11802 ** If successful, a pointer to a buffer containing the inverted changeset
11803 ** is stored in *ppOut, the size of the same buffer is stored in *pnOut, and
11804 ** SQLITE_OK is returned. If an error occurs, both *pnOut and *ppOut are
11805 ** zeroed and an SQLite error code returned.
11806 **
11807 ** It is the responsibility of the caller to eventually call sqlite3_free()
11808 ** on the *ppOut pointer to free the buffer allocation following a successful
11809 ** call to this function.
11810 **
11811 ** WARNING/TODO: This function currently assumes that the input is a valid
11812 ** changeset. If it is not, the results are undefined.
11813 */
11814 SQLITE_API int sqlite3changeset_invert(
11815 int nIn, const void *pIn, /* Input changeset */
11816 int *pnOut, void **ppOut /* OUT: Inverse of input */
11817 );
11818
11819 /*
11820 ** CAPI3REF: Concatenate Two Changeset Objects
11821 **
11822 ** This function is used to concatenate two changesets, A and B, into a
11823 ** single changeset. The result is a changeset equivalent to applying
11824 ** changeset A followed by changeset B.
11825 **
11826 ** This function combines the two input changesets using an
11827 ** sqlite3_changegroup object. Calling it produces similar results as the
11828 ** following code fragment:
11829 **
11830 ** <pre>
11831 ** sqlite3_changegroup *pGrp;
11832 ** rc = sqlite3_changegroup_new(&pGrp);
11833 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nA, pA);
11834 ** if( rc==SQLITE_OK ) rc = sqlite3changegroup_add(pGrp, nB, pB);
11835 ** if( rc==SQLITE_OK ){
11836 ** rc = sqlite3changegroup_output(pGrp, pnOut, ppOut);
11837 ** }else{
11838 ** *ppOut = 0;
11839 ** *pnOut = 0;
11840 ** }
11841 ** </pre>
11842 **
11843 ** Refer to the sqlite3_changegroup documentation below for details.
11844 */
11845 SQLITE_API int sqlite3changeset_concat(
11846 int nA, /* Number of bytes in buffer pA */
11847 void *pA, /* Pointer to buffer containing changeset A */
11848 int nB, /* Number of bytes in buffer pB */
11849 void *pB, /* Pointer to buffer containing changeset B */
11850 int *pnOut, /* OUT: Number of bytes in output changeset */
11851 void **ppOut /* OUT: Buffer containing output changeset */
11852 );
11853
11854
11855 /*
11856 ** CAPI3REF: Upgrade the Schema of a Changeset/Patchset
11857 */
11858 SQLITE_API int sqlite3changeset_upgrade(
11859 sqlite3 *db,
11860 const char *zDb,
11861 int nIn, const void *pIn, /* Input changeset */
11862 int *pnOut, void **ppOut /* OUT: Inverse of input */
11863 );
11864
11865
11866
11867 /*
11868 ** CAPI3REF: Changegroup Handle
11869 **
11870 ** A changegroup is an object used to combine two or more
11871 ** [changesets] or [patchsets]
11872 */
11873 typedef struct sqlite3_changegroup sqlite3_changegroup;
11874
11875 /*
11876 ** CAPI3REF: Create A New Changegroup Object
11877 ** CONSTRUCTOR: sqlite3_changegroup
11878 **
11879 ** An sqlite3_changegroup object is used to combine two or more changesets
11880 ** (or patchsets) into a single changeset (or patchset). A single changegroup
11881 ** object may combine changesets or patchsets, but not both. The output is
11882 ** always in the same format as the input.
11883 **
11884 ** If successful, this function returns SQLITE_OK and populates (*pp) with
11885 ** a pointer to a new sqlite3_changegroup object before returning. The caller
11886 ** should eventually free the returned object using a call to
11887 ** sqlite3changegroup_delete(). If an error occurs, an SQLite error code
11888 ** (i.e. SQLITE_NOMEM) is returned and *pp is set to NULL.
11889 **
11890 ** The usual usage pattern for an sqlite3_changegroup object is as follows:
11891 **
11892 ** <ul>
11893 ** <li> It is created using a call to sqlite3changegroup_new().
11894 **
11895 ** <li> Zero or more changesets (or patchsets) are added to the object
11896 ** by calling sqlite3changegroup_add().
11897 **
11898 ** <li> The result of combining all input changesets together is obtained
11899 ** by the application via a call to sqlite3changegroup_output().
11900 **
11901 ** <li> The object is deleted using a call to sqlite3changegroup_delete().
11902 ** </ul>
11903 **
11904 ** Any number of calls to add() and output() may be made between the calls to
11905 ** new() and delete(), and in any order.
11906 **
11907 ** As well as the regular sqlite3changegroup_add() and
11908 ** sqlite3changegroup_output() functions, also available are the streaming
11909 ** versions sqlite3changegroup_add_strm() and sqlite3changegroup_output_strm().
11910 */
11911 SQLITE_API int sqlite3changegroup_new(sqlite3_changegroup **pp);
11912
11913 /*
11914 ** CAPI3REF: Add a Schema to a Changegroup
11915 ** METHOD: sqlite3_changegroup_schema
11916 **
11917 ** This method may be used to optionally enforce the rule that the changesets
11918 ** added to the changegroup handle must match the schema of database zDb
11919 ** ("main", "temp", or the name of an attached database). If
11920 ** sqlite3changegroup_add() is called to add a changeset that is not compatible
11921 ** with the configured schema, SQLITE_SCHEMA is returned and the changegroup
11922 ** object is left in an undefined state.
11923 **
11924 ** A changeset schema is considered compatible with the database schema in
11925 ** the same way as for sqlite3changeset_apply(). Specifically, for each
11926 ** table in the changeset, there exists a database table with:
11927 **
11928 ** <ul>
11929 ** <li> The name identified by the changeset, and
11930 ** <li> at least as many columns as recorded in the changeset, and
11931 ** <li> the primary key columns in the same position as recorded in
11932 ** the changeset.
11933 ** </ul>
11934 **
11935 ** The output of the changegroup object always has the same schema as the
11936 ** database nominated using this function. In cases where changesets passed
11937 ** to sqlite3changegroup_add() have fewer columns than the corresponding table
11938 ** in the database schema, these are filled in using the default column
11939 ** values from the database schema. This makes it possible to combined
11940 ** changesets that have different numbers of columns for a single table
11941 ** within a changegroup, provided that they are otherwise compatible.
11942 */
11943 SQLITE_API int sqlite3changegroup_schema(sqlite3_changegroup*, sqlite3*, const char *zDb);
11944
11945 /*
11946 ** CAPI3REF: Add A Changeset To A Changegroup
11947 ** METHOD: sqlite3_changegroup
11948 **
11949 ** Add all changes within the changeset (or patchset) in buffer pData (size
11950 ** nData bytes) to the changegroup.
11951 **
11952 ** If the buffer contains a patchset, then all prior calls to this function
11953 ** on the same changegroup object must also have specified patchsets. Or, if
11954 ** the buffer contains a changeset, so must have the earlier calls to this
11955 ** function. Otherwise, SQLITE_ERROR is returned and no changes are added
11956 ** to the changegroup.
11957 **
11958 ** Rows within the changeset and changegroup are identified by the values in
11959 ** their PRIMARY KEY columns. A change in the changeset is considered to
11960 ** apply to the same row as a change already present in the changegroup if
11961 ** the two rows have the same primary key.
11962 **
11963 ** Changes to rows that do not already appear in the changegroup are
11964 ** simply copied into it. Or, if both the new changeset and the changegroup
11965 ** contain changes that apply to a single row, the final contents of the
11966 ** changegroup depends on the type of each change, as follows:
11967 **
11968 ** <table border=1 style="margin-left:8ex;margin-right:8ex">
11969 ** <tr><th style="white-space:pre">Existing Change </th>
11970 ** <th style="white-space:pre">New Change </th>
11971 ** <th>Output Change
11972 ** <tr><td>INSERT <td>INSERT <td>
11973 ** The new change is ignored. This case does not occur if the new
11974 ** changeset was recorded immediately after the changesets already
11975 ** added to the changegroup.
11976 ** <tr><td>INSERT <td>UPDATE <td>
11977 ** The INSERT change remains in the changegroup. The values in the
11978 ** INSERT change are modified as if the row was inserted by the
11979 ** existing change and then updated according to the new change.
11980 ** <tr><td>INSERT <td>DELETE <td>
11981 ** The existing INSERT is removed from the changegroup. The DELETE is
11982 ** not added.
11983 ** <tr><td>UPDATE <td>INSERT <td>
11984 ** The new change is ignored. This case does not occur if the new
11985 ** changeset was recorded immediately after the changesets already
11986 ** added to the changegroup.
11987 ** <tr><td>UPDATE <td>UPDATE <td>
11988 ** The existing UPDATE remains within the changegroup. It is amended
11989 ** so that the accompanying values are as if the row was updated once
11990 ** by the existing change and then again by the new change.
11991 ** <tr><td>UPDATE <td>DELETE <td>
11992 ** The existing UPDATE is replaced by the new DELETE within the
11993 ** changegroup.
11994 ** <tr><td>DELETE <td>INSERT <td>
11995 ** If one or more of the column values in the row inserted by the
11996 ** new change differ from those in the row deleted by the existing
11997 ** change, the existing DELETE is replaced by an UPDATE within the
11998 ** changegroup. Otherwise, if the inserted row is exactly the same
11999 ** as the deleted row, the existing DELETE is simply discarded.
12000 ** <tr><td>DELETE <td>UPDATE <td>
12001 ** The new change is ignored. This case does not occur if the new
12002 ** changeset was recorded immediately after the changesets already
12003 ** added to the changegroup.
12004 ** <tr><td>DELETE <td>DELETE <td>
12005 ** The new change is ignored. This case does not occur if the new
12006 ** changeset was recorded immediately after the changesets already
12007 ** added to the changegroup.
12008 ** </table>
12009 **
12010 ** If the new changeset contains changes to a table that is already present
12011 ** in the changegroup, then the number of columns and the position of the
12012 ** primary key columns for the table must be consistent. If this is not the
12013 ** case, this function fails with SQLITE_SCHEMA. Except, if the changegroup
12014 ** object has been configured with a database schema using the
12015 ** sqlite3changegroup_schema() API, then it is possible to combine changesets
12016 ** with different numbers of columns for a single table, provided that
12017 ** they are otherwise compatible.
12018 **
12019 ** If the input changeset appears to be corrupt and the corruption is
12020 ** detected, SQLITE_CORRUPT is returned. Or, if an out-of-memory condition
12021 ** occurs during processing, this function returns SQLITE_NOMEM.
12022 **
12023 ** In all cases, if an error occurs the state of the final contents of the
12024 ** changegroup is undefined. If no error occurs, SQLITE_OK is returned.
12025 */
12026 SQLITE_API int sqlite3changegroup_add(sqlite3_changegroup*, int nData, void *pData);
12027
12028 /*
12029 ** CAPI3REF: Add A Single Change To A Changegroup
12030 ** METHOD: sqlite3_changegroup
12031 **
12032 ** This function adds the single change currently indicated by the iterator
12033 ** passed as the second argument to the changegroup object. The rules for
12034 ** adding the change are just as described for [sqlite3changegroup_add()].
12035 **
12036 ** If the change is successfully added to the changegroup, SQLITE_OK is
12037 ** returned. Otherwise, an SQLite error code is returned.
12038 **
12039 ** The iterator must point to a valid entry when this function is called.
12040 ** If it does not, SQLITE_ERROR is returned and no change is added to the
12041 ** changegroup. Additionally, the iterator must not have been opened with
12042 ** the SQLITE_CHANGESETAPPLY_INVERT flag. In this case SQLITE_ERROR is also
12043 ** returned.
12044 */
12045 SQLITE_API int sqlite3changegroup_add_change(
12046 sqlite3_changegroup*,
12047 sqlite3_changeset_iter*
12048 );
12049
12050
12051
12052 /*
12053 ** CAPI3REF: Obtain A Composite Changeset From A Changegroup
12054 ** METHOD: sqlite3_changegroup
12055 **
12056 ** Obtain a buffer containing a changeset (or patchset) representing the
12057 ** current contents of the changegroup. If the inputs to the changegroup
12058 ** were themselves changesets, the output is a changeset. Or, if the
12059 ** inputs were patchsets, the output is also a patchset.
12060 **
12061 ** As with the output of the sqlite3session_changeset() and
12062 ** sqlite3session_patchset() functions, all changes related to a single
12063 ** table are grouped together in the output of this function. Tables appear
12064 ** in the same order as for the very first changeset added to the changegroup.
12065 ** If the second or subsequent changesets added to the changegroup contain
12066 ** changes for tables that do not appear in the first changeset, they are
12067 ** appended onto the end of the output changeset, again in the order in
12068 ** which they are first encountered.
12069 **
12070 ** If an error occurs, an SQLite error code is returned and the output
12071 ** variables (*pnData) and (*ppData) are set to 0. Otherwise, SQLITE_OK
12072 ** is returned and the output variables are set to the size of and a
12073 ** pointer to the output buffer, respectively. In this case it is the
12074 ** responsibility of the caller to eventually free the buffer using a
12075 ** call to sqlite3_free().
12076 */
12077 SQLITE_API int sqlite3changegroup_output(
12078 sqlite3_changegroup*,
12079 int *pnData, /* OUT: Size of output buffer in bytes */
12080 void **ppData /* OUT: Pointer to output buffer */
12081 );
12082
12083 /*
12084 ** CAPI3REF: Delete A Changegroup Object
12085 ** DESTRUCTOR: sqlite3_changegroup
12086 */
12087 SQLITE_API void sqlite3changegroup_delete(sqlite3_changegroup*);
12088
12089 /*
12090 ** CAPI3REF: Apply A Changeset To A Database
12091 **
12092 ** Apply a changeset or patchset to a database. These functions attempt to
12093 ** update the "main" database attached to handle db with the changes found in
12094 ** the changeset passed via the second and third arguments.
12095 **
12096 ** The fourth argument (xFilter) passed to these functions is the "filter
12097 ** callback". If it is not NULL, then for each table affected by at least one
12098 ** change in the changeset, the filter callback is invoked with
12099 ** the table name as the second argument, and a copy of the context pointer
12100 ** passed as the sixth argument as the first. If the "filter callback"
12101 ** returns zero, then no attempt is made to apply any changes to the table.
12102 ** Otherwise, if the return value is non-zero or the xFilter argument to
12103 ** is NULL, all changes related to the table are attempted.
12104 **
12105 ** For each table that is not excluded by the filter callback, this function
12106 ** tests that the target database contains a compatible table. A table is
12107 ** considered compatible if all of the following are true:
12108 **
12109 ** <ul>
12110 ** <li> The table has the same name as the name recorded in the
12111 ** changeset, and
12112 ** <li> The table has at least as many columns as recorded in the
12113 ** changeset, and
12114 ** <li> The table has primary key columns in the same position as
12115 ** recorded in the changeset.
12116 ** </ul>
12117 **
12118 ** If there is no compatible table, it is not an error, but none of the
12119 ** changes associated with the table are applied. A warning message is issued
12120 ** via the sqlite3_log() mechanism with the error code SQLITE_SCHEMA. At most
12121 ** one such warning is issued for each table in the changeset.
12122 **
12123 ** For each change for which there is a compatible table, an attempt is made
12124 ** to modify the table contents according to the UPDATE, INSERT or DELETE
12125 ** change. If a change cannot be applied cleanly, the conflict handler
12126 ** function passed as the fifth argument to sqlite3changeset_apply() may be
12127 ** invoked. A description of exactly when the conflict handler is invoked for
12128 ** each type of change is below.
12129 **
12130 ** Unlike the xFilter argument, xConflict may not be passed NULL. The results
12131 ** of passing anything other than a valid function pointer as the xConflict
12132 ** argument are undefined.
12133 **
12134 ** Each time the conflict handler function is invoked, it must return one
12135 ** of [SQLITE_CHANGESET_OMIT], [SQLITE_CHANGESET_ABORT] or
12136 ** [SQLITE_CHANGESET_REPLACE]. SQLITE_CHANGESET_REPLACE may only be returned
12137 ** if the second argument passed to the conflict handler is either
12138 ** SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If the conflict-handler
12139 ** returns an illegal value, any changes already made are rolled back and
12140 ** the call to sqlite3changeset_apply() returns SQLITE_MISUSE. Different
12141 ** actions are taken by sqlite3changeset_apply() depending on the value
12142 ** returned by each invocation of the conflict-handler function. Refer to
12143 ** the documentation for the three
12144 ** [SQLITE_CHANGESET_OMIT|available return values] for details.
12145 **
12146 ** <dl>
12147 ** <dt>DELETE Changes<dd>
12148 ** For each DELETE change, the function checks if the target database
12149 ** contains a row with the same primary key value (or values) as the
12150 ** original row values stored in the changeset. If it does, and the values
12151 ** stored in all non-primary key columns also match the values stored in
12152 ** the changeset the row is deleted from the target database.
12153 **
12154 ** If a row with matching primary key values is found, but one or more of
12155 ** the non-primary key fields contains a value different from the original
12156 ** row value stored in the changeset, the conflict-handler function is
12157 ** invoked with [SQLITE_CHANGESET_DATA] as the second argument. If the
12158 ** database table has more columns than are recorded in the changeset,
12159 ** only the values of those non-primary key fields are compared against
12160 ** the current database contents - any trailing database table columns
12161 ** are ignored.
12162 **
12163 ** If no row with matching primary key values is found in the database,
12164 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
12165 ** passed as the second argument.
12166 **
12167 ** If the DELETE operation is attempted, but SQLite returns SQLITE_CONSTRAINT
12168 ** (which can only happen if a foreign key constraint is violated), the
12169 ** conflict-handler function is invoked with [SQLITE_CHANGESET_CONSTRAINT]
12170 ** passed as the second argument. This includes the case where the DELETE
12171 ** operation is attempted because an earlier call to the conflict handler
12172 ** function returned [SQLITE_CHANGESET_REPLACE].
12173 **
12174 ** <dt>INSERT Changes<dd>
12175 ** For each INSERT change, an attempt is made to insert the new row into
12176 ** the database. If the changeset row contains fewer fields than the
12177 ** database table, the trailing fields are populated with their default
12178 ** values.
12179 **
12180 ** If the attempt to insert the row fails because the database already
12181 ** contains a row with the same primary key values, the conflict handler
12182 ** function is invoked with the second argument set to
12183 ** [SQLITE_CHANGESET_CONFLICT].
12184 **
12185 ** If the attempt to insert the row fails because of some other constraint
12186 ** violation (e.g. NOT NULL or UNIQUE), the conflict handler function is
12187 ** invoked with the second argument set to [SQLITE_CHANGESET_CONSTRAINT].
12188 ** This includes the case where the INSERT operation is re-attempted because
12189 ** an earlier call to the conflict handler function returned
12190 ** [SQLITE_CHANGESET_REPLACE].
12191 **
12192 ** <dt>UPDATE Changes<dd>
12193 ** For each UPDATE change, the function checks if the target database
12194 ** contains a row with the same primary key value (or values) as the
12195 ** original row values stored in the changeset. If it does, and the values
12196 ** stored in all modified non-primary key columns also match the values
12197 ** stored in the changeset the row is updated within the target database.
12198 **
12199 ** If a row with matching primary key values is found, but one or more of
12200 ** the modified non-primary key fields contains a value different from an
12201 ** original row value stored in the changeset, the conflict-handler function
12202 ** is invoked with [SQLITE_CHANGESET_DATA] as the second argument. Since
12203 ** UPDATE changes only contain values for non-primary key fields that are
12204 ** to be modified, only those fields need to match the original values to
12205 ** avoid the SQLITE_CHANGESET_DATA conflict-handler callback.
12206 **
12207 ** If no row with matching primary key values is found in the database,
12208 ** the conflict-handler function is invoked with [SQLITE_CHANGESET_NOTFOUND]
12209 ** passed as the second argument.
12210 **
12211 ** If the UPDATE operation is attempted, but SQLite returns
12212 ** SQLITE_CONSTRAINT, the conflict-handler function is invoked with
12213 ** [SQLITE_CHANGESET_CONSTRAINT] passed as the second argument.
12214 ** This includes the case where the UPDATE operation is attempted after
12215 ** an earlier call to the conflict handler function returned
12216 ** [SQLITE_CHANGESET_REPLACE].
12217 ** </dl>
12218 **
12219 ** It is safe to execute SQL statements, including those that write to the
12220 ** table that the callback related to, from within the xConflict callback.
12221 ** This can be used to further customize the application's conflict
12222 ** resolution strategy.
12223 **
12224 ** All changes made by these functions are enclosed in a savepoint transaction.
12225 ** If any other error (aside from a constraint failure when attempting to
12226 ** write to the target database) occurs, then the savepoint transaction is
12227 ** rolled back, restoring the target database to its original state, and an
12228 ** SQLite error code returned.
12229 **
12230 ** If the output parameters (ppRebase) and (pnRebase) are non-NULL and
12231 ** the input is a changeset (not a patchset), then sqlite3changeset_apply_v2()
12232 ** may set (*ppRebase) to point to a "rebase" that may be used with the
12233 ** sqlite3_rebaser APIs buffer before returning. In this case (*pnRebase)
12234 ** is set to the size of the buffer in bytes. It is the responsibility of the
12235 ** caller to eventually free any such buffer using sqlite3_free(). The buffer
12236 ** is only allocated and populated if one or more conflicts were encountered
12237 ** while applying the patchset. See comments surrounding the sqlite3_rebaser
12238 ** APIs for further details.
12239 **
12240 ** The behavior of sqlite3changeset_apply_v2() and its streaming equivalent
12241 ** may be modified by passing a combination of
12242 ** [SQLITE_CHANGESETAPPLY_NOSAVEPOINT | supported flags] as the 9th parameter.
12243 **
12244 ** Note that the sqlite3changeset_apply_v2() API is still <b>experimental</b>
12245 ** and therefore subject to change.
12246 */
12247 SQLITE_API int sqlite3changeset_apply(
12248 sqlite3 *db, /* Apply change to "main" db of this handle */
12249 int nChangeset, /* Size of changeset in bytes */
12250 void *pChangeset, /* Changeset blob */
12251 int(*xFilter)(
12252 void *pCtx, /* Copy of sixth arg to _apply() */
12253 const char *zTab /* Table name */
12254 ),
12255 int(*xConflict)(
12256 void *pCtx, /* Copy of sixth arg to _apply() */
12257 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
12258 sqlite3_changeset_iter *p /* Handle describing change and conflict */
12259 ),
12260 void *pCtx /* First argument passed to xConflict */
12261 );
12262 SQLITE_API int sqlite3changeset_apply_v2(
12263 sqlite3 *db, /* Apply change to "main" db of this handle */
12264 int nChangeset, /* Size of changeset in bytes */
12265 void *pChangeset, /* Changeset blob */
12266 int(*xFilter)(
12267 void *pCtx, /* Copy of sixth arg to _apply() */
12268 const char *zTab /* Table name */
12269 ),
12270 int(*xConflict)(
12271 void *pCtx, /* Copy of sixth arg to _apply() */
12272 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
12273 sqlite3_changeset_iter *p /* Handle describing change and conflict */
12274 ),
12275 void *pCtx, /* First argument passed to xConflict */
12276 void **ppRebase, int *pnRebase, /* OUT: Rebase data */
12277 int flags /* SESSION_CHANGESETAPPLY_* flags */
12278 );
12279
12280 /*
12281 ** CAPI3REF: Flags for sqlite3changeset_apply_v2
12282 **
12283 ** The following flags may passed via the 9th parameter to
12284 ** [sqlite3changeset_apply_v2] and [sqlite3changeset_apply_v2_strm]:
12285 **
12286 ** <dl>
12287 ** <dt>SQLITE_CHANGESETAPPLY_NOSAVEPOINT <dd>
12288 ** Usually, the sessions module encloses all operations performed by
12289 ** a single call to apply_v2() or apply_v2_strm() in a [SAVEPOINT]. The
12290 ** SAVEPOINT is committed if the changeset or patchset is successfully
12291 ** applied, or rolled back if an error occurs. Specifying this flag
12292 ** causes the sessions module to omit this savepoint. In this case, if the
12293 ** caller has an open transaction or savepoint when apply_v2() is called,
12294 ** it may revert the partially applied changeset by rolling it back.
12295 **
12296 ** <dt>SQLITE_CHANGESETAPPLY_INVERT <dd>
12297 ** Invert the changeset before applying it. This is equivalent to inverting
12298 ** a changeset using sqlite3changeset_invert() before applying it. It is
12299 ** an error to specify this flag with a patchset.
12300 **
12301 ** <dt>SQLITE_CHANGESETAPPLY_IGNORENOOP <dd>
12302 ** Do not invoke the conflict handler callback for any changes that
12303 ** would not actually modify the database even if they were applied.
12304 ** Specifically, this means that the conflict handler is not invoked
12305 ** for:
12306 ** <ul>
12307 ** <li>a delete change if the row being deleted cannot be found,
12308 ** <li>an update change if the modified fields are already set to
12309 ** their new values in the conflicting row, or
12310 ** <li>an insert change if all fields of the conflicting row match
12311 ** the row being inserted.
12312 ** </ul>
12313 **
12314 ** <dt>SQLITE_CHANGESETAPPLY_FKNOACTION <dd>
12315 ** If this flag it set, then all foreign key constraints in the target
12316 ** database behave as if they were declared with "ON UPDATE NO ACTION ON
12317 ** DELETE NO ACTION", even if they are actually CASCADE, RESTRICT, SET NULL
12318 ** or SET DEFAULT.
12319 */
12320 #define SQLITE_CHANGESETAPPLY_NOSAVEPOINT 0x0001
12321 #define SQLITE_CHANGESETAPPLY_INVERT 0x0002
12322 #define SQLITE_CHANGESETAPPLY_IGNORENOOP 0x0004
12323 #define SQLITE_CHANGESETAPPLY_FKNOACTION 0x0008
12324
12325 /*
12326 ** CAPI3REF: Constants Passed To The Conflict Handler
12327 **
12328 ** Values that may be passed as the second argument to a conflict-handler.
12329 **
12330 ** <dl>
12331 ** <dt>SQLITE_CHANGESET_DATA<dd>
12332 ** The conflict handler is invoked with CHANGESET_DATA as the second argument
12333 ** when processing a DELETE or UPDATE change if a row with the required
12334 ** PRIMARY KEY fields is present in the database, but one or more other
12335 ** (non primary-key) fields modified by the update do not contain the
12336 ** expected "before" values.
12337 **
12338 ** The conflicting row, in this case, is the database row with the matching
12339 ** primary key.
12340 **
12341 ** <dt>SQLITE_CHANGESET_NOTFOUND<dd>
12342 ** The conflict handler is invoked with CHANGESET_NOTFOUND as the second
12343 ** argument when processing a DELETE or UPDATE change if a row with the
12344 ** required PRIMARY KEY fields is not present in the database.
12345 **
12346 ** There is no conflicting row in this case. The results of invoking the
12347 ** sqlite3changeset_conflict() API are undefined.
12348 **
12349 ** <dt>SQLITE_CHANGESET_CONFLICT<dd>
12350 ** CHANGESET_CONFLICT is passed as the second argument to the conflict
12351 ** handler while processing an INSERT change if the operation would result
12352 ** in duplicate primary key values.
12353 **
12354 ** The conflicting row in this case is the database row with the matching
12355 ** primary key.
12356 **
12357 ** <dt>SQLITE_CHANGESET_FOREIGN_KEY<dd>
12358 ** If foreign key handling is enabled, and applying a changeset leaves the
12359 ** database in a state containing foreign key violations, the conflict
12360 ** handler is invoked with CHANGESET_FOREIGN_KEY as the second argument
12361 ** exactly once before the changeset is committed. If the conflict handler
12362 ** returns CHANGESET_OMIT, the changes, including those that caused the
12363 ** foreign key constraint violation, are committed. Or, if it returns
12364 ** CHANGESET_ABORT, the changeset is rolled back.
12365 **
12366 ** No current or conflicting row information is provided. The only function
12367 ** it is possible to call on the supplied sqlite3_changeset_iter handle
12368 ** is sqlite3changeset_fk_conflicts().
12369 **
12370 ** <dt>SQLITE_CHANGESET_CONSTRAINT<dd>
12371 ** If any other constraint violation occurs while applying a change (i.e.
12372 ** a UNIQUE, CHECK or NOT NULL constraint), the conflict handler is
12373 ** invoked with CHANGESET_CONSTRAINT as the second argument.
12374 **
12375 ** There is no conflicting row in this case. The results of invoking the
12376 ** sqlite3changeset_conflict() API are undefined.
12377 **
12378 ** </dl>
12379 */
12380 #define SQLITE_CHANGESET_DATA 1
12381 #define SQLITE_CHANGESET_NOTFOUND 2
12382 #define SQLITE_CHANGESET_CONFLICT 3
12383 #define SQLITE_CHANGESET_CONSTRAINT 4
12384 #define SQLITE_CHANGESET_FOREIGN_KEY 5
12385
12386 /*
12387 ** CAPI3REF: Constants Returned By The Conflict Handler
12388 **
12389 ** A conflict handler callback must return one of the following three values.
12390 **
12391 ** <dl>
12392 ** <dt>SQLITE_CHANGESET_OMIT<dd>
12393 ** If a conflict handler returns this value no special action is taken. The
12394 ** change that caused the conflict is not applied. The session module
12395 ** continues to the next change in the changeset.
12396 **
12397 ** <dt>SQLITE_CHANGESET_REPLACE<dd>
12398 ** This value may only be returned if the second argument to the conflict
12399 ** handler was SQLITE_CHANGESET_DATA or SQLITE_CHANGESET_CONFLICT. If this
12400 ** is not the case, any changes applied so far are rolled back and the
12401 ** call to sqlite3changeset_apply() returns SQLITE_MISUSE.
12402 **
12403 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_DATA conflict
12404 ** handler, then the conflicting row is either updated or deleted, depending
12405 ** on the type of change.
12406 **
12407 ** If CHANGESET_REPLACE is returned by an SQLITE_CHANGESET_CONFLICT conflict
12408 ** handler, then the conflicting row is removed from the database and a
12409 ** second attempt to apply the change is made. If this second attempt fails,
12410 ** the original row is restored to the database before continuing.
12411 **
12412 ** <dt>SQLITE_CHANGESET_ABORT<dd>
12413 ** If this value is returned, any changes applied so far are rolled back
12414 ** and the call to sqlite3changeset_apply() returns SQLITE_ABORT.
12415 ** </dl>
12416 */
12417 #define SQLITE_CHANGESET_OMIT 0
12418 #define SQLITE_CHANGESET_REPLACE 1
12419 #define SQLITE_CHANGESET_ABORT 2
12420
12421 /*
12422 ** CAPI3REF: Rebasing changesets
12423 ** EXPERIMENTAL
12424 **
12425 ** Suppose there is a site hosting a database in state S0. And that
12426 ** modifications are made that move that database to state S1 and a
12427 ** changeset recorded (the "local" changeset). Then, a changeset based
12428 ** on S0 is received from another site (the "remote" changeset) and
12429 ** applied to the database. The database is then in state
12430 ** (S1+"remote"), where the exact state depends on any conflict
12431 ** resolution decisions (OMIT or REPLACE) made while applying "remote".
12432 ** Rebasing a changeset is to update it to take those conflict
12433 ** resolution decisions into account, so that the same conflicts
12434 ** do not have to be resolved elsewhere in the network.
12435 **
12436 ** For example, if both the local and remote changesets contain an
12437 ** INSERT of the same key on "CREATE TABLE t1(a PRIMARY KEY, b)":
12438 **
12439 ** local: INSERT INTO t1 VALUES(1, 'v1');
12440 ** remote: INSERT INTO t1 VALUES(1, 'v2');
12441 **
12442 ** and the conflict resolution is REPLACE, then the INSERT change is
12443 ** removed from the local changeset (it was overridden). Or, if the
12444 ** conflict resolution was "OMIT", then the local changeset is modified
12445 ** to instead contain:
12446 **
12447 ** UPDATE t1 SET b = 'v2' WHERE a=1;
12448 **
12449 ** Changes within the local changeset are rebased as follows:
12450 **
12451 ** <dl>
12452 ** <dt>Local INSERT<dd>
12453 ** This may only conflict with a remote INSERT. If the conflict
12454 ** resolution was OMIT, then add an UPDATE change to the rebased
12455 ** changeset. Or, if the conflict resolution was REPLACE, add
12456 ** nothing to the rebased changeset.
12457 **
12458 ** <dt>Local DELETE<dd>
12459 ** This may conflict with a remote UPDATE or DELETE. In both cases the
12460 ** only possible resolution is OMIT. If the remote operation was a
12461 ** DELETE, then add no change to the rebased changeset. If the remote
12462 ** operation was an UPDATE, then the old.* fields of change are updated
12463 ** to reflect the new.* values in the UPDATE.
12464 **
12465 ** <dt>Local UPDATE<dd>
12466 ** This may conflict with a remote UPDATE or DELETE. If it conflicts
12467 ** with a DELETE, and the conflict resolution was OMIT, then the update
12468 ** is changed into an INSERT. Any undefined values in the new.* record
12469 ** from the update change are filled in using the old.* values from
12470 ** the conflicting DELETE. Or, if the conflict resolution was REPLACE,
12471 ** the UPDATE change is simply omitted from the rebased changeset.
12472 **
12473 ** If conflict is with a remote UPDATE and the resolution is OMIT, then
12474 ** the old.* values are rebased using the new.* values in the remote
12475 ** change. Or, if the resolution is REPLACE, then the change is copied
12476 ** into the rebased changeset with updates to columns also updated by
12477 ** the conflicting remote UPDATE removed. If this means no columns would
12478 ** be updated, the change is omitted.
12479 ** </dl>
12480 **
12481 ** A local change may be rebased against multiple remote changes
12482 ** simultaneously. If a single key is modified by multiple remote
12483 ** changesets, they are combined as follows before the local changeset
12484 ** is rebased:
12485 **
12486 ** <ul>
12487 ** <li> If there has been one or more REPLACE resolutions on a
12488 ** key, it is rebased according to a REPLACE.
12489 **
12490 ** <li> If there have been no REPLACE resolutions on a key, then
12491 ** the local changeset is rebased according to the most recent
12492 ** of the OMIT resolutions.
12493 ** </ul>
12494 **
12495 ** Note that conflict resolutions from multiple remote changesets are
12496 ** combined on a per-field basis, not per-row. This means that in the
12497 ** case of multiple remote UPDATE operations, some fields of a single
12498 ** local change may be rebased for REPLACE while others are rebased for
12499 ** OMIT.
12500 **
12501 ** In order to rebase a local changeset, the remote changeset must first
12502 ** be applied to the local database using sqlite3changeset_apply_v2() and
12503 ** the buffer of rebase information captured. Then:
12504 **
12505 ** <ol>
12506 ** <li> An sqlite3_rebaser object is created by calling
12507 ** sqlite3rebaser_create().
12508 ** <li> The new object is configured with the rebase buffer obtained from
12509 ** sqlite3changeset_apply_v2() by calling sqlite3rebaser_configure().
12510 ** If the local changeset is to be rebased against multiple remote
12511 ** changesets, then sqlite3rebaser_configure() should be called
12512 ** multiple times, in the same order that the multiple
12513 ** sqlite3changeset_apply_v2() calls were made.
12514 ** <li> Each local changeset is rebased by calling sqlite3rebaser_rebase().
12515 ** <li> The sqlite3_rebaser object is deleted by calling
12516 ** sqlite3rebaser_delete().
12517 ** </ol>
12518 */
12519 typedef struct sqlite3_rebaser sqlite3_rebaser;
12520
12521 /*
12522 ** CAPI3REF: Create a changeset rebaser object.
12523 ** EXPERIMENTAL
12524 **
12525 ** Allocate a new changeset rebaser object. If successful, set (*ppNew) to
12526 ** point to the new object and return SQLITE_OK. Otherwise, if an error
12527 ** occurs, return an SQLite error code (e.g. SQLITE_NOMEM) and set (*ppNew)
12528 ** to NULL.
12529 */
12530 SQLITE_API int sqlite3rebaser_create(sqlite3_rebaser **ppNew);
12531
12532 /*
12533 ** CAPI3REF: Configure a changeset rebaser object.
12534 ** EXPERIMENTAL
12535 **
12536 ** Configure the changeset rebaser object to rebase changesets according
12537 ** to the conflict resolutions described by buffer pRebase (size nRebase
12538 ** bytes), which must have been obtained from a previous call to
12539 ** sqlite3changeset_apply_v2().
12540 */
12541 SQLITE_API int sqlite3rebaser_configure(
12542 sqlite3_rebaser*,
12543 int nRebase, const void *pRebase
12544 );
12545
12546 /*
12547 ** CAPI3REF: Rebase a changeset
12548 ** EXPERIMENTAL
12549 **
12550 ** Argument pIn must point to a buffer containing a changeset nIn bytes
12551 ** in size. This function allocates and populates a buffer with a copy
12552 ** of the changeset rebased according to the configuration of the
12553 ** rebaser object passed as the first argument. If successful, (*ppOut)
12554 ** is set to point to the new buffer containing the rebased changeset and
12555 ** (*pnOut) to its size in bytes and SQLITE_OK returned. It is the
12556 ** responsibility of the caller to eventually free the new buffer using
12557 ** sqlite3_free(). Otherwise, if an error occurs, (*ppOut) and (*pnOut)
12558 ** are set to zero and an SQLite error code returned.
12559 */
12560 SQLITE_API int sqlite3rebaser_rebase(
12561 sqlite3_rebaser*,
12562 int nIn, const void *pIn,
12563 int *pnOut, void **ppOut
12564 );
12565
12566 /*
12567 ** CAPI3REF: Delete a changeset rebaser object.
12568 ** EXPERIMENTAL
12569 **
12570 ** Delete the changeset rebaser object and all associated resources. There
12571 ** should be one call to this function for each successful invocation
12572 ** of sqlite3rebaser_create().
12573 */
12574 SQLITE_API void sqlite3rebaser_delete(sqlite3_rebaser *p);
12575
12576 /*
12577 ** CAPI3REF: Streaming Versions of API functions.
12578 **
12579 ** The six streaming API xxx_strm() functions serve similar purposes to the
12580 ** corresponding non-streaming API functions:
12581 **
12582 ** <table border=1 style="margin-left:8ex;margin-right:8ex">
12583 ** <tr><th>Streaming function<th>Non-streaming equivalent</th>
12584 ** <tr><td>sqlite3changeset_apply_strm<td>[sqlite3changeset_apply]
12585 ** <tr><td>sqlite3changeset_apply_strm_v2<td>[sqlite3changeset_apply_v2]
12586 ** <tr><td>sqlite3changeset_concat_strm<td>[sqlite3changeset_concat]
12587 ** <tr><td>sqlite3changeset_invert_strm<td>[sqlite3changeset_invert]
12588 ** <tr><td>sqlite3changeset_start_strm<td>[sqlite3changeset_start]
12589 ** <tr><td>sqlite3session_changeset_strm<td>[sqlite3session_changeset]
12590 ** <tr><td>sqlite3session_patchset_strm<td>[sqlite3session_patchset]
12591 ** </table>
12592 **
12593 ** Non-streaming functions that accept changesets (or patchsets) as input
12594 ** require that the entire changeset be stored in a single buffer in memory.
12595 ** Similarly, those that return a changeset or patchset do so by returning
12596 ** a pointer to a single large buffer allocated using sqlite3_malloc().
12597 ** Normally this is convenient. However, if an application running in a
12598 ** low-memory environment is required to handle very large changesets, the
12599 ** large contiguous memory allocations required can become onerous.
12600 **
12601 ** In order to avoid this problem, instead of a single large buffer, input
12602 ** is passed to a streaming API functions by way of a callback function that
12603 ** the sessions module invokes to incrementally request input data as it is
12604 ** required. In all cases, a pair of API function parameters such as
12605 **
12606 ** <pre>
12607 ** &nbsp; int nChangeset,
12608 ** &nbsp; void *pChangeset,
12609 ** </pre>
12610 **
12611 ** Is replaced by:
12612 **
12613 ** <pre>
12614 ** &nbsp; int (*xInput)(void *pIn, void *pData, int *pnData),
12615 ** &nbsp; void *pIn,
12616 ** </pre>
12617 **
12618 ** Each time the xInput callback is invoked by the sessions module, the first
12619 ** argument passed is a copy of the supplied pIn context pointer. The second
12620 ** argument, pData, points to a buffer (*pnData) bytes in size. Assuming no
12621 ** error occurs the xInput method should copy up to (*pnData) bytes of data
12622 ** into the buffer and set (*pnData) to the actual number of bytes copied
12623 ** before returning SQLITE_OK. If the input is completely exhausted, (*pnData)
12624 ** should be set to zero to indicate this. Or, if an error occurs, an SQLite
12625 ** error code should be returned. In all cases, if an xInput callback returns
12626 ** an error, all processing is abandoned and the streaming API function
12627 ** returns a copy of the error code to the caller.
12628 **
12629 ** In the case of sqlite3changeset_start_strm(), the xInput callback may be
12630 ** invoked by the sessions module at any point during the lifetime of the
12631 ** iterator. If such an xInput callback returns an error, the iterator enters
12632 ** an error state, whereby all subsequent calls to iterator functions
12633 ** immediately fail with the same error code as returned by xInput.
12634 **
12635 ** Similarly, streaming API functions that return changesets (or patchsets)
12636 ** return them in chunks by way of a callback function instead of via a
12637 ** pointer to a single large buffer. In this case, a pair of parameters such
12638 ** as:
12639 **
12640 ** <pre>
12641 ** &nbsp; int *pnChangeset,
12642 ** &nbsp; void **ppChangeset,
12643 ** </pre>
12644 **
12645 ** Is replaced by:
12646 **
12647 ** <pre>
12648 ** &nbsp; int (*xOutput)(void *pOut, const void *pData, int nData),
12649 ** &nbsp; void *pOut
12650 ** </pre>
12651 **
12652 ** The xOutput callback is invoked zero or more times to return data to
12653 ** the application. The first parameter passed to each call is a copy of the
12654 ** pOut pointer supplied by the application. The second parameter, pData,
12655 ** points to a buffer nData bytes in size containing the chunk of output
12656 ** data being returned. If the xOutput callback successfully processes the
12657 ** supplied data, it should return SQLITE_OK to indicate success. Otherwise,
12658 ** it should return some other SQLite error code. In this case processing
12659 ** is immediately abandoned and the streaming API function returns a copy
12660 ** of the xOutput error code to the application.
12661 **
12662 ** The sessions module never invokes an xOutput callback with the third
12663 ** parameter set to a value less than or equal to zero. Other than this,
12664 ** no guarantees are made as to the size of the chunks of data returned.
12665 */
12666 SQLITE_API int sqlite3changeset_apply_strm(
12667 sqlite3 *db, /* Apply change to "main" db of this handle */
12668 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
12669 void *pIn, /* First arg for xInput */
12670 int(*xFilter)(
12671 void *pCtx, /* Copy of sixth arg to _apply() */
12672 const char *zTab /* Table name */
12673 ),
12674 int(*xConflict)(
12675 void *pCtx, /* Copy of sixth arg to _apply() */
12676 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
12677 sqlite3_changeset_iter *p /* Handle describing change and conflict */
12678 ),
12679 void *pCtx /* First argument passed to xConflict */
12680 );
12681 SQLITE_API int sqlite3changeset_apply_v2_strm(
12682 sqlite3 *db, /* Apply change to "main" db of this handle */
12683 int (*xInput)(void *pIn, void *pData, int *pnData), /* Input function */
12684 void *pIn, /* First arg for xInput */
12685 int(*xFilter)(
12686 void *pCtx, /* Copy of sixth arg to _apply() */
12687 const char *zTab /* Table name */
12688 ),
12689 int(*xConflict)(
12690 void *pCtx, /* Copy of sixth arg to _apply() */
12691 int eConflict, /* DATA, MISSING, CONFLICT, CONSTRAINT */
12692 sqlite3_changeset_iter *p /* Handle describing change and conflict */
12693 ),
12694 void *pCtx, /* First argument passed to xConflict */
12695 void **ppRebase, int *pnRebase,
12696 int flags
12697 );
12698 SQLITE_API int sqlite3changeset_concat_strm(
12699 int (*xInputA)(void *pIn, void *pData, int *pnData),
12700 void *pInA,
12701 int (*xInputB)(void *pIn, void *pData, int *pnData),
12702 void *pInB,
12703 int (*xOutput)(void *pOut, const void *pData, int nData),
12704 void *pOut
12705 );
12706 SQLITE_API int sqlite3changeset_invert_strm(
12707 int (*xInput)(void *pIn, void *pData, int *pnData),
12708 void *pIn,
12709 int (*xOutput)(void *pOut, const void *pData, int nData),
12710 void *pOut
12711 );
12712 SQLITE_API int sqlite3changeset_start_strm(
12713 sqlite3_changeset_iter **pp,
12714 int (*xInput)(void *pIn, void *pData, int *pnData),
12715 void *pIn
12716 );
12717 SQLITE_API int sqlite3changeset_start_v2_strm(
12718 sqlite3_changeset_iter **pp,
12719 int (*xInput)(void *pIn, void *pData, int *pnData),
12720 void *pIn,
12721 int flags
12722 );
12723 SQLITE_API int sqlite3session_changeset_strm(
12724 sqlite3_session *pSession,
12725 int (*xOutput)(void *pOut, const void *pData, int nData),
12726 void *pOut
12727 );
12728 SQLITE_API int sqlite3session_patchset_strm(
12729 sqlite3_session *pSession,
12730 int (*xOutput)(void *pOut, const void *pData, int nData),
12731 void *pOut
12732 );
12733 SQLITE_API int sqlite3changegroup_add_strm(sqlite3_changegroup*,
12734 int (*xInput)(void *pIn, void *pData, int *pnData),
12735 void *pIn
12736 );
12737 SQLITE_API int sqlite3changegroup_output_strm(sqlite3_changegroup*,
12738 int (*xOutput)(void *pOut, const void *pData, int nData),
12739 void *pOut
12740 );
12741 SQLITE_API int sqlite3rebaser_rebase_strm(
12742 sqlite3_rebaser *pRebaser,
12743 int (*xInput)(void *pIn, void *pData, int *pnData),
12744 void *pIn,
12745 int (*xOutput)(void *pOut, const void *pData, int nData),
12746 void *pOut
12747 );
12748
12749 /*
12750 ** CAPI3REF: Configure global parameters
12751 **
12752 ** The sqlite3session_config() interface is used to make global configuration
12753 ** changes to the sessions module in order to tune it to the specific needs
12754 ** of the application.
12755 **
12756 ** The sqlite3session_config() interface is not threadsafe. If it is invoked
12757 ** while any other thread is inside any other sessions method then the
12758 ** results are undefined. Furthermore, if it is invoked after any sessions
12759 ** related objects have been created, the results are also undefined.
12760 **
12761 ** The first argument to the sqlite3session_config() function must be one
12762 ** of the SQLITE_SESSION_CONFIG_XXX constants defined below. The
12763 ** interpretation of the (void*) value passed as the second parameter and
12764 ** the effect of calling this function depends on the value of the first
12765 ** parameter.
12766 **
12767 ** <dl>
12768 ** <dt>SQLITE_SESSION_CONFIG_STRMSIZE<dd>
12769 ** By default, the sessions module streaming interfaces attempt to input
12770 ** and output data in approximately 1 KiB chunks. This operand may be used
12771 ** to set and query the value of this configuration setting. The pointer
12772 ** passed as the second argument must point to a value of type (int).
12773 ** If this value is greater than 0, it is used as the new streaming data
12774 ** chunk size for both input and output. Before returning, the (int) value
12775 ** pointed to by pArg is set to the final value of the streaming interface
12776 ** chunk size.
12777 ** </dl>
12778 **
12779 ** This function returns SQLITE_OK if successful, or an SQLite error code
12780 ** otherwise.
12781 */
12782 SQLITE_API int sqlite3session_config(int op, void *pArg);
12783
12784 /*
12785 ** CAPI3REF: Values for sqlite3session_config().
12786 */
12787 #define SQLITE_SESSION_CONFIG_STRMSIZE 1
12788
12789 /*
12790 ** Make sure we can call this stuff from C++.
12791 */
12792 #ifdef __cplusplus
12793 }
12794 #endif
12795
12796 #endif /* !defined(__SQLITESESSION_H_) && defined(SQLITE_ENABLE_SESSION) */
12797
12798 /******** End of sqlite3session.h *********/
12799 /******** Begin file fts5.h *********/
12800 /*
12801 ** 2014 May 31
12802 **
12803 ** The author disclaims copyright to this source code. In place of
12804 ** a legal notice, here is a blessing:
12805 **
12806 ** May you do good and not evil.
12807 ** May you find forgiveness for yourself and forgive others.
12808 ** May you share freely, never taking more than you give.
12809 **
12810 ******************************************************************************
12811 **
12812 ** Interfaces to extend FTS5. Using the interfaces defined in this file,
12813 ** FTS5 may be extended with:
12814 **
12815 ** * custom tokenizers, and
12816 ** * custom auxiliary functions.
12817 */
12818
12819
12820 #ifndef _FTS5_H
12821 #define _FTS5_H
12822
12823
12824 #ifdef __cplusplus
12825 extern "C" {
12826 #endif
12827
12828 /*************************************************************************
12829 ** CUSTOM AUXILIARY FUNCTIONS
12830 **
12831 ** Virtual table implementations may overload SQL functions by implementing
12832 ** the sqlite3_module.xFindFunction() method.
12833 */
12834
12835 typedef struct Fts5ExtensionApi Fts5ExtensionApi;
12836 typedef struct Fts5Context Fts5Context;
12837 typedef struct Fts5PhraseIter Fts5PhraseIter;
12838
12839 typedef void (*fts5_extension_function)(
12840 const Fts5ExtensionApi *pApi, /* API offered by current FTS version */
12841 Fts5Context *pFts, /* First arg to pass to pApi functions */
12842 sqlite3_context *pCtx, /* Context for returning result/error */
12843 int nVal, /* Number of values in apVal[] array */
12844 sqlite3_value **apVal /* Array of trailing arguments */
12845 );
12846
12847 struct Fts5PhraseIter {
12848 const unsigned char *a;
12849 const unsigned char *b;
12850 };
12851
12852 /*
12853 ** EXTENSION API FUNCTIONS
12854 **
12855 ** xUserData(pFts):
12856 ** Return a copy of the pUserData pointer passed to the xCreateFunction()
12857 ** API when the extension function was registered.
12858 **
12859 ** xColumnTotalSize(pFts, iCol, pnToken):
12860 ** If parameter iCol is less than zero, set output variable *pnToken
12861 ** to the total number of tokens in the FTS5 table. Or, if iCol is
12862 ** non-negative but less than the number of columns in the table, return
12863 ** the total number of tokens in column iCol, considering all rows in
12864 ** the FTS5 table.
12865 **
12866 ** If parameter iCol is greater than or equal to the number of columns
12867 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
12868 ** an OOM condition or IO error), an appropriate SQLite error code is
12869 ** returned.
12870 **
12871 ** xColumnCount(pFts):
12872 ** Return the number of columns in the table.
12873 **
12874 ** xColumnSize(pFts, iCol, pnToken):
12875 ** If parameter iCol is less than zero, set output variable *pnToken
12876 ** to the total number of tokens in the current row. Or, if iCol is
12877 ** non-negative but less than the number of columns in the table, set
12878 ** *pnToken to the number of tokens in column iCol of the current row.
12879 **
12880 ** If parameter iCol is greater than or equal to the number of columns
12881 ** in the table, SQLITE_RANGE is returned. Or, if an error occurs (e.g.
12882 ** an OOM condition or IO error), an appropriate SQLite error code is
12883 ** returned.
12884 **
12885 ** This function may be quite inefficient if used with an FTS5 table
12886 ** created with the "columnsize=0" option.
12887 **
12888 ** xColumnText:
12889 ** If parameter iCol is less than zero, or greater than or equal to the
12890 ** number of columns in the table, SQLITE_RANGE is returned.
12891 **
12892 ** Otherwise, this function attempts to retrieve the text of column iCol of
12893 ** the current document. If successful, (*pz) is set to point to a buffer
12894 ** containing the text in utf-8 encoding, (*pn) is set to the size in bytes
12895 ** (not characters) of the buffer and SQLITE_OK is returned. Otherwise,
12896 ** if an error occurs, an SQLite error code is returned and the final values
12897 ** of (*pz) and (*pn) are undefined.
12898 **
12899 ** xPhraseCount:
12900 ** Returns the number of phrases in the current query expression.
12901 **
12902 ** xPhraseSize:
12903 ** If parameter iCol is less than zero, or greater than or equal to the
12904 ** number of phrases in the current query, as returned by xPhraseCount,
12905 ** 0 is returned. Otherwise, this function returns the number of tokens in
12906 ** phrase iPhrase of the query. Phrases are numbered starting from zero.
12907 **
12908 ** xInstCount:
12909 ** Set *pnInst to the total number of occurrences of all phrases within
12910 ** the query within the current row. Return SQLITE_OK if successful, or
12911 ** an error code (i.e. SQLITE_NOMEM) if an error occurs.
12912 **
12913 ** This API can be quite slow if used with an FTS5 table created with the
12914 ** "detail=none" or "detail=column" option. If the FTS5 table is created
12915 ** with either "detail=none" or "detail=column" and "content=" option
12916 ** (i.e. if it is a contentless table), then this API always returns 0.
12917 **
12918 ** xInst:
12919 ** Query for the details of phrase match iIdx within the current row.
12920 ** Phrase matches are numbered starting from zero, so the iIdx argument
12921 ** should be greater than or equal to zero and smaller than the value
12922 ** output by xInstCount(). If iIdx is less than zero or greater than
12923 ** or equal to the value returned by xInstCount(), SQLITE_RANGE is returned.
12924 **
12925 ** Otherwise, output parameter *piPhrase is set to the phrase number, *piCol
12926 ** to the column in which it occurs and *piOff the token offset of the
12927 ** first token of the phrase. SQLITE_OK is returned if successful, or an
12928 ** error code (i.e. SQLITE_NOMEM) if an error occurs.
12929 **
12930 ** This API can be quite slow if used with an FTS5 table created with the
12931 ** "detail=none" or "detail=column" option.
12932 **
12933 ** xRowid:
12934 ** Returns the rowid of the current row.
12935 **
12936 ** xTokenize:
12937 ** Tokenize text using the tokenizer belonging to the FTS5 table.
12938 **
12939 ** xQueryPhrase(pFts5, iPhrase, pUserData, xCallback):
12940 ** This API function is used to query the FTS table for phrase iPhrase
12941 ** of the current query. Specifically, a query equivalent to:
12942 **
12943 ** ... FROM ftstable WHERE ftstable MATCH $p ORDER BY rowid
12944 **
12945 ** with $p set to a phrase equivalent to the phrase iPhrase of the
12946 ** current query is executed. Any column filter that applies to
12947 ** phrase iPhrase of the current query is included in $p. For each
12948 ** row visited, the callback function passed as the fourth argument
12949 ** is invoked. The context and API objects passed to the callback
12950 ** function may be used to access the properties of each matched row.
12951 ** Invoking Api.xUserData() returns a copy of the pointer passed as
12952 ** the third argument to pUserData.
12953 **
12954 ** If parameter iPhrase is less than zero, or greater than or equal to
12955 ** the number of phrases in the query, as returned by xPhraseCount(),
12956 ** this function returns SQLITE_RANGE.
12957 **
12958 ** If the callback function returns any value other than SQLITE_OK, the
12959 ** query is abandoned and the xQueryPhrase function returns immediately.
12960 ** If the returned value is SQLITE_DONE, xQueryPhrase returns SQLITE_OK.
12961 ** Otherwise, the error code is propagated upwards.
12962 **
12963 ** If the query runs to completion without incident, SQLITE_OK is returned.
12964 ** Or, if some error occurs before the query completes or is aborted by
12965 ** the callback, an SQLite error code is returned.
12966 **
12967 **
12968 ** xSetAuxdata(pFts5, pAux, xDelete)
12969 **
12970 ** Save the pointer passed as the second argument as the extension function's
12971 ** "auxiliary data". The pointer may then be retrieved by the current or any
12972 ** future invocation of the same fts5 extension function made as part of
12973 ** the same MATCH query using the xGetAuxdata() API.
12974 **
12975 ** Each extension function is allocated a single auxiliary data slot for
12976 ** each FTS query (MATCH expression). If the extension function is invoked
12977 ** more than once for a single FTS query, then all invocations share a
12978 ** single auxiliary data context.
12979 **
12980 ** If there is already an auxiliary data pointer when this function is
12981 ** invoked, then it is replaced by the new pointer. If an xDelete callback
12982 ** was specified along with the original pointer, it is invoked at this
12983 ** point.
12984 **
12985 ** The xDelete callback, if one is specified, is also invoked on the
12986 ** auxiliary data pointer after the FTS5 query has finished.
12987 **
12988 ** If an error (e.g. an OOM condition) occurs within this function,
12989 ** the auxiliary data is set to NULL and an error code returned. If the
12990 ** xDelete parameter was not NULL, it is invoked on the auxiliary data
12991 ** pointer before returning.
12992 **
12993 **
12994 ** xGetAuxdata(pFts5, bClear)
12995 **
12996 ** Returns the current auxiliary data pointer for the fts5 extension
12997 ** function. See the xSetAuxdata() method for details.
12998 **
12999 ** If the bClear argument is non-zero, then the auxiliary data is cleared
13000 ** (set to NULL) before this function returns. In this case the xDelete,
13001 ** if any, is not invoked.
13002 **
13003 **
13004 ** xRowCount(pFts5, pnRow)
13005 **
13006 ** This function is used to retrieve the total number of rows in the table.
13007 ** In other words, the same value that would be returned by:
13008 **
13009 ** SELECT count(*) FROM ftstable;
13010 **
13011 ** xPhraseFirst()
13012 ** This function is used, along with type Fts5PhraseIter and the xPhraseNext
13013 ** method, to iterate through all instances of a single query phrase within
13014 ** the current row. This is the same information as is accessible via the
13015 ** xInstCount/xInst APIs. While the xInstCount/xInst APIs are more convenient
13016 ** to use, this API may be faster under some circumstances. To iterate
13017 ** through instances of phrase iPhrase, use the following code:
13018 **
13019 ** Fts5PhraseIter iter;
13020 ** int iCol, iOff;
13021 ** for(pApi->xPhraseFirst(pFts, iPhrase, &iter, &iCol, &iOff);
13022 ** iCol>=0;
13023 ** pApi->xPhraseNext(pFts, &iter, &iCol, &iOff)
13024 ** ){
13025 ** // An instance of phrase iPhrase at offset iOff of column iCol
13026 ** }
13027 **
13028 ** The Fts5PhraseIter structure is defined above. Applications should not
13029 ** modify this structure directly - it should only be used as shown above
13030 ** with the xPhraseFirst() and xPhraseNext() API methods (and by
13031 ** xPhraseFirstColumn() and xPhraseNextColumn() as illustrated below).
13032 **
13033 ** This API can be quite slow if used with an FTS5 table created with the
13034 ** "detail=none" or "detail=column" option. If the FTS5 table is created
13035 ** with either "detail=none" or "detail=column" and "content=" option
13036 ** (i.e. if it is a contentless table), then this API always iterates
13037 ** through an empty set (all calls to xPhraseFirst() set iCol to -1).
13038 **
13039 ** xPhraseNext()
13040 ** See xPhraseFirst above.
13041 **
13042 ** xPhraseFirstColumn()
13043 ** This function and xPhraseNextColumn() are similar to the xPhraseFirst()
13044 ** and xPhraseNext() APIs described above. The difference is that instead
13045 ** of iterating through all instances of a phrase in the current row, these
13046 ** APIs are used to iterate through the set of columns in the current row
13047 ** that contain one or more instances of a specified phrase. For example:
13048 **
13049 ** Fts5PhraseIter iter;
13050 ** int iCol;
13051 ** for(pApi->xPhraseFirstColumn(pFts, iPhrase, &iter, &iCol);
13052 ** iCol>=0;
13053 ** pApi->xPhraseNextColumn(pFts, &iter, &iCol)
13054 ** ){
13055 ** // Column iCol contains at least one instance of phrase iPhrase
13056 ** }
13057 **
13058 ** This API can be quite slow if used with an FTS5 table created with the
13059 ** "detail=none" option. If the FTS5 table is created with either
13060 ** "detail=none" "content=" option (i.e. if it is a contentless table),
13061 ** then this API always iterates through an empty set (all calls to
13062 ** xPhraseFirstColumn() set iCol to -1).
13063 **
13064 ** The information accessed using this API and its companion
13065 ** xPhraseFirstColumn() may also be obtained using xPhraseFirst/xPhraseNext
13066 ** (or xInst/xInstCount). The chief advantage of this API is that it is
13067 ** significantly more efficient than those alternatives when used with
13068 ** "detail=column" tables.
13069 **
13070 ** xPhraseNextColumn()
13071 ** See xPhraseFirstColumn above.
13072 **
13073 ** xQueryToken(pFts5, iPhrase, iToken, ppToken, pnToken)
13074 ** This is used to access token iToken of phrase iPhrase of the current
13075 ** query. Before returning, output parameter *ppToken is set to point
13076 ** to a buffer containing the requested token, and *pnToken to the
13077 ** size of this buffer in bytes.
13078 **
13079 ** If iPhrase or iToken are less than zero, or if iPhrase is greater than
13080 ** or equal to the number of phrases in the query as reported by
13081 ** xPhraseCount(), or if iToken is equal to or greater than the number of
13082 ** tokens in the phrase, SQLITE_RANGE is returned and *ppToken and *pnToken
13083 are both zeroed.
13084 **
13085 ** The output text is not a copy of the query text that specified the
13086 ** token. It is the output of the tokenizer module. For tokendata=1
13087 ** tables, this includes any embedded 0x00 and trailing data.
13088 **
13089 ** xInstToken(pFts5, iIdx, iToken, ppToken, pnToken)
13090 ** This is used to access token iToken of phrase hit iIdx within the
13091 ** current row. If iIdx is less than zero or greater than or equal to the
13092 ** value returned by xInstCount(), SQLITE_RANGE is returned. Otherwise,
13093 ** output variable (*ppToken) is set to point to a buffer containing the
13094 ** matching document token, and (*pnToken) to the size of that buffer in
13095 ** bytes. This API is not available if the specified token matches a
13096 ** prefix query term. In that case both output variables are always set
13097 ** to 0.
13098 **
13099 ** The output text is not a copy of the document text that was tokenized.
13100 ** It is the output of the tokenizer module. For tokendata=1 tables, this
13101 ** includes any embedded 0x00 and trailing data.
13102 **
13103 ** This API can be quite slow if used with an FTS5 table created with the
13104 ** "detail=none" or "detail=column" option.
13105 */
13106 struct Fts5ExtensionApi {
13107 int iVersion; /* Currently always set to 3 */
13108
13109 void *(*xUserData)(Fts5Context*);
13110
13111 int (*xColumnCount)(Fts5Context*);
13112 int (*xRowCount)(Fts5Context*, sqlite3_int64 *pnRow);
13113 int (*xColumnTotalSize)(Fts5Context*, int iCol, sqlite3_int64 *pnToken);
13114
13115 int (*xTokenize)(Fts5Context*,
13116 const char *pText, int nText, /* Text to tokenize */
13117 void *pCtx, /* Context passed to xToken() */
13118 int (*xToken)(void*, int, const char*, int, int, int) /* Callback */
13119 );
13120
13121 int (*xPhraseCount)(Fts5Context*);
13122 int (*xPhraseSize)(Fts5Context*, int iPhrase);
13123
13124 int (*xInstCount)(Fts5Context*, int *pnInst);
13125 int (*xInst)(Fts5Context*, int iIdx, int *piPhrase, int *piCol, int *piOff);
13126
13127 sqlite3_int64 (*xRowid)(Fts5Context*);
13128 int (*xColumnText)(Fts5Context*, int iCol, const char **pz, int *pn);
13129 int (*xColumnSize)(Fts5Context*, int iCol, int *pnToken);
13130
13131 int (*xQueryPhrase)(Fts5Context*, int iPhrase, void *pUserData,
13132 int(*)(const Fts5ExtensionApi*,Fts5Context*,void*)
13133 );
13134 int (*xSetAuxdata)(Fts5Context*, void *pAux, void(*xDelete)(void*));
13135 void *(*xGetAuxdata)(Fts5Context*, int bClear);
13136
13137 int (*xPhraseFirst)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*, int*);
13138 void (*xPhraseNext)(Fts5Context*, Fts5PhraseIter*, int *piCol, int *piOff);
13139
13140 int (*xPhraseFirstColumn)(Fts5Context*, int iPhrase, Fts5PhraseIter*, int*);
13141 void (*xPhraseNextColumn)(Fts5Context*, Fts5PhraseIter*, int *piCol);
13142
13143 /* Below this point are iVersion>=3 only */
13144 int (*xQueryToken)(Fts5Context*,
13145 int iPhrase, int iToken,
13146 const char **ppToken, int *pnToken
13147 );
13148 int (*xInstToken)(Fts5Context*, int iIdx, int iToken, const char**, int*);
13149 };
13150
13151 /*
13152 ** CUSTOM AUXILIARY FUNCTIONS
13153 *************************************************************************/
13154
13155 /*************************************************************************
13156 ** CUSTOM TOKENIZERS
13157 **
13158 ** Applications may also register custom tokenizer types. A tokenizer
13159 ** is registered by providing fts5 with a populated instance of the
13160 ** following structure. All structure methods must be defined, setting
13161 ** any member of the fts5_tokenizer struct to NULL leads to undefined
13162 ** behaviour. The structure methods are expected to function as follows:
13163 **
13164 ** xCreate:
13165 ** This function is used to allocate and initialize a tokenizer instance.
13166 ** A tokenizer instance is required to actually tokenize text.
13167 **
13168 ** The first argument passed to this function is a copy of the (void*)
13169 ** pointer provided by the application when the fts5_tokenizer object
13170 ** was registered with FTS5 (the third argument to xCreateTokenizer()).
13171 ** The second and third arguments are an array of nul-terminated strings
13172 ** containing the tokenizer arguments, if any, specified following the
13173 ** tokenizer name as part of the CREATE VIRTUAL TABLE statement used
13174 ** to create the FTS5 table.
13175 **
13176 ** The final argument is an output variable. If successful, (*ppOut)
13177 ** should be set to point to the new tokenizer handle and SQLITE_OK
13178 ** returned. If an error occurs, some value other than SQLITE_OK should
13179 ** be returned. In this case, fts5 assumes that the final value of *ppOut
13180 ** is undefined.
13181 **
13182 ** xDelete:
13183 ** This function is invoked to delete a tokenizer handle previously
13184 ** allocated using xCreate(). Fts5 guarantees that this function will
13185 ** be invoked exactly once for each successful call to xCreate().
13186 **
13187 ** xTokenize:
13188 ** This function is expected to tokenize the nText byte string indicated
13189 ** by argument pText. pText may or may not be nul-terminated. The first
13190 ** argument passed to this function is a pointer to an Fts5Tokenizer object
13191 ** returned by an earlier call to xCreate().
13192 **
13193 ** The second argument indicates the reason that FTS5 is requesting
13194 ** tokenization of the supplied text. This is always one of the following
13195 ** four values:
13196 **
13197 ** <ul><li> <b>FTS5_TOKENIZE_DOCUMENT</b> - A document is being inserted into
13198 ** or removed from the FTS table. The tokenizer is being invoked to
13199 ** determine the set of tokens to add to (or delete from) the
13200 ** FTS index.
13201 **
13202 ** <li> <b>FTS5_TOKENIZE_QUERY</b> - A MATCH query is being executed
13203 ** against the FTS index. The tokenizer is being called to tokenize
13204 ** a bareword or quoted string specified as part of the query.
13205 **
13206 ** <li> <b>(FTS5_TOKENIZE_QUERY | FTS5_TOKENIZE_PREFIX)</b> - Same as
13207 ** FTS5_TOKENIZE_QUERY, except that the bareword or quoted string is
13208 ** followed by a "*" character, indicating that the last token
13209 ** returned by the tokenizer will be treated as a token prefix.
13210 **
13211 ** <li> <b>FTS5_TOKENIZE_AUX</b> - The tokenizer is being invoked to
13212 ** satisfy an fts5_api.xTokenize() request made by an auxiliary
13213 ** function. Or an fts5_api.xColumnSize() request made by the same
13214 ** on a columnsize=0 database.
13215 ** </ul>
13216 **
13217 ** For each token in the input string, the supplied callback xToken() must
13218 ** be invoked. The first argument to it should be a copy of the pointer
13219 ** passed as the second argument to xTokenize(). The third and fourth
13220 ** arguments are a pointer to a buffer containing the token text, and the
13221 ** size of the token in bytes. The 4th and 5th arguments are the byte offsets
13222 ** of the first byte of and first byte immediately following the text from
13223 ** which the token is derived within the input.
13224 **
13225 ** The second argument passed to the xToken() callback ("tflags") should
13226 ** normally be set to 0. The exception is if the tokenizer supports
13227 ** synonyms. In this case see the discussion below for details.
13228 **
13229 ** FTS5 assumes the xToken() callback is invoked for each token in the
13230 ** order that they occur within the input text.
13231 **
13232 ** If an xToken() callback returns any value other than SQLITE_OK, then
13233 ** the tokenization should be abandoned and the xTokenize() method should
13234 ** immediately return a copy of the xToken() return value. Or, if the
13235 ** input buffer is exhausted, xTokenize() should return SQLITE_OK. Finally,
13236 ** if an error occurs with the xTokenize() implementation itself, it
13237 ** may abandon the tokenization and return any error code other than
13238 ** SQLITE_OK or SQLITE_DONE.
13239 **
13240 ** SYNONYM SUPPORT
13241 **
13242 ** Custom tokenizers may also support synonyms. Consider a case in which a
13243 ** user wishes to query for a phrase such as "first place". Using the
13244 ** built-in tokenizers, the FTS5 query 'first + place' will match instances
13245 ** of "first place" within the document set, but not alternative forms
13246 ** such as "1st place". In some applications, it would be better to match
13247 ** all instances of "first place" or "1st place" regardless of which form
13248 ** the user specified in the MATCH query text.
13249 **
13250 ** There are several ways to approach this in FTS5:
13251 **
13252 ** <ol><li> By mapping all synonyms to a single token. In this case, using
13253 ** the above example, this means that the tokenizer returns the
13254 ** same token for inputs "first" and "1st". Say that token is in
13255 ** fact "first", so that when the user inserts the document "I won
13256 ** 1st place" entries are added to the index for tokens "i", "won",
13257 ** "first" and "place". If the user then queries for '1st + place',
13258 ** the tokenizer substitutes "first" for "1st" and the query works
13259 ** as expected.
13260 **
13261 ** <li> By querying the index for all synonyms of each query term
13262 ** separately. In this case, when tokenizing query text, the
13263 ** tokenizer may provide multiple synonyms for a single term
13264 ** within the document. FTS5 then queries the index for each
13265 ** synonym individually. For example, faced with the query:
13266 **
13267 ** <codeblock>
13268 ** ... MATCH 'first place'</codeblock>
13269 **
13270 ** the tokenizer offers both "1st" and "first" as synonyms for the
13271 ** first token in the MATCH query and FTS5 effectively runs a query
13272 ** similar to:
13273 **
13274 ** <codeblock>
13275 ** ... MATCH '(first OR 1st) place'</codeblock>
13276 **
13277 ** except that, for the purposes of auxiliary functions, the query
13278 ** still appears to contain just two phrases - "(first OR 1st)"
13279 ** being treated as a single phrase.
13280 **
13281 ** <li> By adding multiple synonyms for a single term to the FTS index.
13282 ** Using this method, when tokenizing document text, the tokenizer
13283 ** provides multiple synonyms for each token. So that when a
13284 ** document such as "I won first place" is tokenized, entries are
13285 ** added to the FTS index for "i", "won", "first", "1st" and
13286 ** "place".
13287 **
13288 ** This way, even if the tokenizer does not provide synonyms
13289 ** when tokenizing query text (it should not - to do so would be
13290 ** inefficient), it doesn't matter if the user queries for
13291 ** 'first + place' or '1st + place', as there are entries in the
13292 ** FTS index corresponding to both forms of the first token.
13293 ** </ol>
13294 **
13295 ** Whether it is parsing document or query text, any call to xToken that
13296 ** specifies a <i>tflags</i> argument with the FTS5_TOKEN_COLOCATED bit
13297 ** is considered to supply a synonym for the previous token. For example,
13298 ** when parsing the document "I won first place", a tokenizer that supports
13299 ** synonyms would call xToken() 5 times, as follows:
13300 **
13301 ** <codeblock>
13302 ** xToken(pCtx, 0, "i", 1, 0, 1);
13303 ** xToken(pCtx, 0, "won", 3, 2, 5);
13304 ** xToken(pCtx, 0, "first", 5, 6, 11);
13305 ** xToken(pCtx, FTS5_TOKEN_COLOCATED, "1st", 3, 6, 11);
13306 ** xToken(pCtx, 0, "place", 5, 12, 17);
13307 **</codeblock>
13308 **
13309 ** It is an error to specify the FTS5_TOKEN_COLOCATED flag the first time
13310 ** xToken() is called. Multiple synonyms may be specified for a single token
13311 ** by making multiple calls to xToken(FTS5_TOKEN_COLOCATED) in sequence.
13312 ** There is no limit to the number of synonyms that may be provided for a
13313 ** single token.
13314 **
13315 ** In many cases, method (1) above is the best approach. It does not add
13316 ** extra data to the FTS index or require FTS5 to query for multiple terms,
13317 ** so it is efficient in terms of disk space and query speed. However, it
13318 ** does not support prefix queries very well. If, as suggested above, the
13319 ** token "first" is substituted for "1st" by the tokenizer, then the query:
13320 **
13321 ** <codeblock>
13322 ** ... MATCH '1s*'</codeblock>
13323 **
13324 ** will not match documents that contain the token "1st" (as the tokenizer
13325 ** will probably not map "1s" to any prefix of "first").
13326 **
13327 ** For full prefix support, method (3) may be preferred. In this case,
13328 ** because the index contains entries for both "first" and "1st", prefix
13329 ** queries such as 'fi*' or '1s*' will match correctly. However, because
13330 ** extra entries are added to the FTS index, this method uses more space
13331 ** within the database.
13332 **
13333 ** Method (2) offers a midpoint between (1) and (3). Using this method,
13334 ** a query such as '1s*' will match documents that contain the literal
13335 ** token "1st", but not "first" (assuming the tokenizer is not able to
13336 ** provide synonyms for prefixes). However, a non-prefix query like '1st'
13337 ** will match against "1st" and "first". This method does not require
13338 ** extra disk space, as no extra entries are added to the FTS index.
13339 ** On the other hand, it may require more CPU cycles to run MATCH queries,
13340 ** as separate queries of the FTS index are required for each synonym.
13341 **
13342 ** When using methods (2) or (3), it is important that the tokenizer only
13343 ** provide synonyms when tokenizing document text (method (3)) or query
13344 ** text (method (2)), not both. Doing so will not cause any errors, but is
13345 ** inefficient.
13346 */
13347 typedef struct Fts5Tokenizer Fts5Tokenizer;
13348 typedef struct fts5_tokenizer fts5_tokenizer;
13349 struct fts5_tokenizer {
13350 int (*xCreate)(void*, const char **azArg, int nArg, Fts5Tokenizer **ppOut);
13351 void (*xDelete)(Fts5Tokenizer*);
13352 int (*xTokenize)(Fts5Tokenizer*,
13353 void *pCtx,
13354 int flags, /* Mask of FTS5_TOKENIZE_* flags */
13355 const char *pText, int nText,
13356 int (*xToken)(
13357 void *pCtx, /* Copy of 2nd argument to xTokenize() */
13358 int tflags, /* Mask of FTS5_TOKEN_* flags */
13359 const char *pToken, /* Pointer to buffer containing token */
13360 int nToken, /* Size of token in bytes */
13361 int iStart, /* Byte offset of token within input text */
13362 int iEnd /* Byte offset of end of token within input text */
13363 )
13364 );
13365 };
13366
13367 /* Flags that may be passed as the third argument to xTokenize() */
13368 #define FTS5_TOKENIZE_QUERY 0x0001
13369 #define FTS5_TOKENIZE_PREFIX 0x0002
13370 #define FTS5_TOKENIZE_DOCUMENT 0x0004
13371 #define FTS5_TOKENIZE_AUX 0x0008
13372
13373 /* Flags that may be passed by the tokenizer implementation back to FTS5
13374 ** as the third argument to the supplied xToken callback. */
13375 #define FTS5_TOKEN_COLOCATED 0x0001 /* Same position as prev. token */
13376
13377 /*
13378 ** END OF CUSTOM TOKENIZERS
13379 *************************************************************************/
13380
13381 /*************************************************************************
13382 ** FTS5 EXTENSION REGISTRATION API
13383 */
13384 typedef struct fts5_api fts5_api;
13385 struct fts5_api {
13386 int iVersion; /* Currently always set to 2 */
13387
13388 /* Create a new tokenizer */
13389 int (*xCreateTokenizer)(
13390 fts5_api *pApi,
13391 const char *zName,
13392 void *pUserData,
13393 fts5_tokenizer *pTokenizer,
13394 void (*xDestroy)(void*)
13395 );
13396
13397 /* Find an existing tokenizer */
13398 int (*xFindTokenizer)(
13399 fts5_api *pApi,
13400 const char *zName,
13401 void **ppUserData,
13402 fts5_tokenizer *pTokenizer
13403 );
13404
13405 /* Create a new auxiliary function */
13406 int (*xCreateFunction)(
13407 fts5_api *pApi,
13408 const char *zName,
13409 void *pUserData,
13410 fts5_extension_function xFunction,
13411 void (*xDestroy)(void*)
13412 );
13413 };
13414
13415 /*
13416 ** END OF REGISTRATION API
13417 *************************************************************************/
13418
13419 #ifdef __cplusplus
13420 } /* end of the 'extern "C"' block */
13421 #endif
13422
13423 #endif /* _FTS5_H */
13424
13425 /******** End of fts5.h *********/