jpayne@69: /* zlib.h -- interface of the 'zlib' general purpose compression library jpayne@69: version 1.2.13, October 13th, 2022 jpayne@69: jpayne@69: Copyright (C) 1995-2022 Jean-loup Gailly and Mark Adler jpayne@69: jpayne@69: This software is provided 'as-is', without any express or implied jpayne@69: warranty. In no event will the authors be held liable for any damages jpayne@69: arising from the use of this software. jpayne@69: jpayne@69: Permission is granted to anyone to use this software for any purpose, jpayne@69: including commercial applications, and to alter it and redistribute it jpayne@69: freely, subject to the following restrictions: jpayne@69: jpayne@69: 1. The origin of this software must not be misrepresented; you must not jpayne@69: claim that you wrote the original software. If you use this software jpayne@69: in a product, an acknowledgment in the product documentation would be jpayne@69: appreciated but is not required. jpayne@69: 2. Altered source versions must be plainly marked as such, and must not be jpayne@69: misrepresented as being the original software. jpayne@69: 3. This notice may not be removed or altered from any source distribution. jpayne@69: jpayne@69: Jean-loup Gailly Mark Adler jpayne@69: jloup@gzip.org madler@alumni.caltech.edu jpayne@69: jpayne@69: jpayne@69: The data format used by the zlib library is described by RFCs (Request for jpayne@69: Comments) 1950 to 1952 in the files http://tools.ietf.org/html/rfc1950 jpayne@69: (zlib format), rfc1951 (deflate format) and rfc1952 (gzip format). jpayne@69: */ jpayne@69: jpayne@69: #ifndef ZLIB_H jpayne@69: #define ZLIB_H jpayne@69: jpayne@69: #include "zconf.h" jpayne@69: jpayne@69: #ifdef __cplusplus jpayne@69: extern "C" { jpayne@69: #endif jpayne@69: jpayne@69: #define ZLIB_VERSION "1.2.13" jpayne@69: #define ZLIB_VERNUM 0x12d0 jpayne@69: #define ZLIB_VER_MAJOR 1 jpayne@69: #define ZLIB_VER_MINOR 2 jpayne@69: #define ZLIB_VER_REVISION 13 jpayne@69: #define ZLIB_VER_SUBREVISION 0 jpayne@69: jpayne@69: /* jpayne@69: The 'zlib' compression library provides in-memory compression and jpayne@69: decompression functions, including integrity checks of the uncompressed data. jpayne@69: This version of the library supports only one compression method (deflation) jpayne@69: but other algorithms will be added later and will have the same stream jpayne@69: interface. jpayne@69: jpayne@69: Compression can be done in a single step if the buffers are large enough, jpayne@69: or can be done by repeated calls of the compression function. In the latter jpayne@69: case, the application must provide more input and/or consume the output jpayne@69: (providing more output space) before each call. jpayne@69: jpayne@69: The compressed data format used by default by the in-memory functions is jpayne@69: the zlib format, which is a zlib wrapper documented in RFC 1950, wrapped jpayne@69: around a deflate stream, which is itself documented in RFC 1951. jpayne@69: jpayne@69: The library also supports reading and writing files in gzip (.gz) format jpayne@69: with an interface similar to that of stdio using the functions that start jpayne@69: with "gz". The gzip format is different from the zlib format. gzip is a jpayne@69: gzip wrapper, documented in RFC 1952, wrapped around a deflate stream. jpayne@69: jpayne@69: This library can optionally read and write gzip and raw deflate streams in jpayne@69: memory as well. jpayne@69: jpayne@69: The zlib format was designed to be compact and fast for use in memory jpayne@69: and on communications channels. The gzip format was designed for single- jpayne@69: file compression on file systems, has a larger header than zlib to maintain jpayne@69: directory information, and uses a different, slower check method than zlib. jpayne@69: jpayne@69: The library does not install any signal handler. The decoder checks jpayne@69: the consistency of the compressed data, so the library should never crash jpayne@69: even in the case of corrupted input. jpayne@69: */ jpayne@69: jpayne@69: typedef voidpf (*alloc_func) OF((voidpf opaque, uInt items, uInt size)); jpayne@69: typedef void (*free_func) OF((voidpf opaque, voidpf address)); jpayne@69: jpayne@69: struct internal_state; jpayne@69: jpayne@69: typedef struct z_stream_s { jpayne@69: z_const Bytef *next_in; /* next input byte */ jpayne@69: uInt avail_in; /* number of bytes available at next_in */ jpayne@69: uLong total_in; /* total number of input bytes read so far */ jpayne@69: jpayne@69: Bytef *next_out; /* next output byte will go here */ jpayne@69: uInt avail_out; /* remaining free space at next_out */ jpayne@69: uLong total_out; /* total number of bytes output so far */ jpayne@69: jpayne@69: z_const char *msg; /* last error message, NULL if no error */ jpayne@69: struct internal_state FAR *state; /* not visible by applications */ jpayne@69: jpayne@69: alloc_func zalloc; /* used to allocate the internal state */ jpayne@69: free_func zfree; /* used to free the internal state */ jpayne@69: voidpf opaque; /* private data object passed to zalloc and zfree */ jpayne@69: jpayne@69: int data_type; /* best guess about the data type: binary or text jpayne@69: for deflate, or the decoding state for inflate */ jpayne@69: uLong adler; /* Adler-32 or CRC-32 value of the uncompressed data */ jpayne@69: uLong reserved; /* reserved for future use */ jpayne@69: } z_stream; jpayne@69: jpayne@69: typedef z_stream FAR *z_streamp; jpayne@69: jpayne@69: /* jpayne@69: gzip header information passed to and from zlib routines. See RFC 1952 jpayne@69: for more details on the meanings of these fields. jpayne@69: */ jpayne@69: typedef struct gz_header_s { jpayne@69: int text; /* true if compressed data believed to be text */ jpayne@69: uLong time; /* modification time */ jpayne@69: int xflags; /* extra flags (not used when writing a gzip file) */ jpayne@69: int os; /* operating system */ jpayne@69: Bytef *extra; /* pointer to extra field or Z_NULL if none */ jpayne@69: uInt extra_len; /* extra field length (valid if extra != Z_NULL) */ jpayne@69: uInt extra_max; /* space at extra (only when reading header) */ jpayne@69: Bytef *name; /* pointer to zero-terminated file name or Z_NULL */ jpayne@69: uInt name_max; /* space at name (only when reading header) */ jpayne@69: Bytef *comment; /* pointer to zero-terminated comment or Z_NULL */ jpayne@69: uInt comm_max; /* space at comment (only when reading header) */ jpayne@69: int hcrc; /* true if there was or will be a header crc */ jpayne@69: int done; /* true when done reading gzip header (not used jpayne@69: when writing a gzip file) */ jpayne@69: } gz_header; jpayne@69: jpayne@69: typedef gz_header FAR *gz_headerp; jpayne@69: jpayne@69: /* jpayne@69: The application must update next_in and avail_in when avail_in has dropped jpayne@69: to zero. It must update next_out and avail_out when avail_out has dropped jpayne@69: to zero. The application must initialize zalloc, zfree and opaque before jpayne@69: calling the init function. All other fields are set by the compression jpayne@69: library and must not be updated by the application. jpayne@69: jpayne@69: The opaque value provided by the application will be passed as the first jpayne@69: parameter for calls of zalloc and zfree. This can be useful for custom jpayne@69: memory management. The compression library attaches no meaning to the jpayne@69: opaque value. jpayne@69: jpayne@69: zalloc must return Z_NULL if there is not enough memory for the object. jpayne@69: If zlib is used in a multi-threaded application, zalloc and zfree must be jpayne@69: thread safe. In that case, zlib is thread-safe. When zalloc and zfree are jpayne@69: Z_NULL on entry to the initialization function, they are set to internal jpayne@69: routines that use the standard library functions malloc() and free(). jpayne@69: jpayne@69: On 16-bit systems, the functions zalloc and zfree must be able to allocate jpayne@69: exactly 65536 bytes, but will not be required to allocate more than this if jpayne@69: the symbol MAXSEG_64K is defined (see zconf.h). WARNING: On MSDOS, pointers jpayne@69: returned by zalloc for objects of exactly 65536 bytes *must* have their jpayne@69: offset normalized to zero. The default allocation function provided by this jpayne@69: library ensures this (see zutil.c). To reduce memory requirements and avoid jpayne@69: any allocation of 64K objects, at the expense of compression ratio, compile jpayne@69: the library with -DMAX_WBITS=14 (see zconf.h). jpayne@69: jpayne@69: The fields total_in and total_out can be used for statistics or progress jpayne@69: reports. After compression, total_in holds the total size of the jpayne@69: uncompressed data and may be saved for use by the decompressor (particularly jpayne@69: if the decompressor wants to decompress everything in a single step). jpayne@69: */ jpayne@69: jpayne@69: /* constants */ jpayne@69: jpayne@69: #define Z_NO_FLUSH 0 jpayne@69: #define Z_PARTIAL_FLUSH 1 jpayne@69: #define Z_SYNC_FLUSH 2 jpayne@69: #define Z_FULL_FLUSH 3 jpayne@69: #define Z_FINISH 4 jpayne@69: #define Z_BLOCK 5 jpayne@69: #define Z_TREES 6 jpayne@69: /* Allowed flush values; see deflate() and inflate() below for details */ jpayne@69: jpayne@69: #define Z_OK 0 jpayne@69: #define Z_STREAM_END 1 jpayne@69: #define Z_NEED_DICT 2 jpayne@69: #define Z_ERRNO (-1) jpayne@69: #define Z_STREAM_ERROR (-2) jpayne@69: #define Z_DATA_ERROR (-3) jpayne@69: #define Z_MEM_ERROR (-4) jpayne@69: #define Z_BUF_ERROR (-5) jpayne@69: #define Z_VERSION_ERROR (-6) jpayne@69: /* Return codes for the compression/decompression functions. Negative values jpayne@69: * are errors, positive values are used for special but normal events. jpayne@69: */ jpayne@69: jpayne@69: #define Z_NO_COMPRESSION 0 jpayne@69: #define Z_BEST_SPEED 1 jpayne@69: #define Z_BEST_COMPRESSION 9 jpayne@69: #define Z_DEFAULT_COMPRESSION (-1) jpayne@69: /* compression levels */ jpayne@69: jpayne@69: #define Z_FILTERED 1 jpayne@69: #define Z_HUFFMAN_ONLY 2 jpayne@69: #define Z_RLE 3 jpayne@69: #define Z_FIXED 4 jpayne@69: #define Z_DEFAULT_STRATEGY 0 jpayne@69: /* compression strategy; see deflateInit2() below for details */ jpayne@69: jpayne@69: #define Z_BINARY 0 jpayne@69: #define Z_TEXT 1 jpayne@69: #define Z_ASCII Z_TEXT /* for compatibility with 1.2.2 and earlier */ jpayne@69: #define Z_UNKNOWN 2 jpayne@69: /* Possible values of the data_type field for deflate() */ jpayne@69: jpayne@69: #define Z_DEFLATED 8 jpayne@69: /* The deflate compression method (the only one supported in this version) */ jpayne@69: jpayne@69: #define Z_NULL 0 /* for initializing zalloc, zfree, opaque */ jpayne@69: jpayne@69: #define zlib_version zlibVersion() jpayne@69: /* for compatibility with versions < 1.0.2 */ jpayne@69: jpayne@69: jpayne@69: /* basic functions */ jpayne@69: jpayne@69: ZEXTERN const char * ZEXPORT zlibVersion OF((void)); jpayne@69: /* The application can compare zlibVersion and ZLIB_VERSION for consistency. jpayne@69: If the first character differs, the library code actually used is not jpayne@69: compatible with the zlib.h header file used by the application. This check jpayne@69: is automatically made by deflateInit and inflateInit. jpayne@69: */ jpayne@69: jpayne@69: /* jpayne@69: ZEXTERN int ZEXPORT deflateInit OF((z_streamp strm, int level)); jpayne@69: jpayne@69: Initializes the internal stream state for compression. The fields jpayne@69: zalloc, zfree and opaque must be initialized before by the caller. If jpayne@69: zalloc and zfree are set to Z_NULL, deflateInit updates them to use default jpayne@69: allocation functions. jpayne@69: jpayne@69: The compression level must be Z_DEFAULT_COMPRESSION, or between 0 and 9: jpayne@69: 1 gives best speed, 9 gives best compression, 0 gives no compression at all jpayne@69: (the input data is simply copied a block at a time). Z_DEFAULT_COMPRESSION jpayne@69: requests a default compromise between speed and compression (currently jpayne@69: equivalent to level 6). jpayne@69: jpayne@69: deflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough jpayne@69: memory, Z_STREAM_ERROR if level is not a valid compression level, or jpayne@69: Z_VERSION_ERROR if the zlib library version (zlib_version) is incompatible jpayne@69: with the version assumed by the caller (ZLIB_VERSION). msg is set to null jpayne@69: if there is no error message. deflateInit does not perform any compression: jpayne@69: this will be done by deflate(). jpayne@69: */ jpayne@69: jpayne@69: jpayne@69: ZEXTERN int ZEXPORT deflate OF((z_streamp strm, int flush)); jpayne@69: /* jpayne@69: deflate compresses as much data as possible, and stops when the input jpayne@69: buffer becomes empty or the output buffer becomes full. It may introduce jpayne@69: some output latency (reading input without producing any output) except when jpayne@69: forced to flush. jpayne@69: jpayne@69: The detailed semantics are as follows. deflate performs one or both of the jpayne@69: following actions: jpayne@69: jpayne@69: - Compress more input starting at next_in and update next_in and avail_in jpayne@69: accordingly. If not all input can be processed (because there is not jpayne@69: enough room in the output buffer), next_in and avail_in are updated and jpayne@69: processing will resume at this point for the next call of deflate(). jpayne@69: jpayne@69: - Generate more output starting at next_out and update next_out and avail_out jpayne@69: accordingly. This action is forced if the parameter flush is non zero. jpayne@69: Forcing flush frequently degrades the compression ratio, so this parameter jpayne@69: should be set only when necessary. Some output may be provided even if jpayne@69: flush is zero. jpayne@69: jpayne@69: Before the call of deflate(), the application should ensure that at least jpayne@69: one of the actions is possible, by providing more input and/or consuming more jpayne@69: output, and updating avail_in or avail_out accordingly; avail_out should jpayne@69: never be zero before the call. The application can consume the compressed jpayne@69: output when it wants, for example when the output buffer is full (avail_out jpayne@69: == 0), or after each call of deflate(). If deflate returns Z_OK and with jpayne@69: zero avail_out, it must be called again after making room in the output jpayne@69: buffer because there might be more output pending. See deflatePending(), jpayne@69: which can be used if desired to determine whether or not there is more output jpayne@69: in that case. jpayne@69: jpayne@69: Normally the parameter flush is set to Z_NO_FLUSH, which allows deflate to jpayne@69: decide how much data to accumulate before producing output, in order to jpayne@69: maximize compression. jpayne@69: jpayne@69: If the parameter flush is set to Z_SYNC_FLUSH, all pending output is jpayne@69: flushed to the output buffer and the output is aligned on a byte boundary, so jpayne@69: that the decompressor can get all input data available so far. (In jpayne@69: particular avail_in is zero after the call if enough output space has been jpayne@69: provided before the call.) Flushing may degrade compression for some jpayne@69: compression algorithms and so it should be used only when necessary. This jpayne@69: completes the current deflate block and follows it with an empty stored block jpayne@69: that is three bits plus filler bits to the next byte, followed by four bytes jpayne@69: (00 00 ff ff). jpayne@69: jpayne@69: If flush is set to Z_PARTIAL_FLUSH, all pending output is flushed to the jpayne@69: output buffer, but the output is not aligned to a byte boundary. All of the jpayne@69: input data so far will be available to the decompressor, as for Z_SYNC_FLUSH. jpayne@69: This completes the current deflate block and follows it with an empty fixed jpayne@69: codes block that is 10 bits long. This assures that enough bytes are output jpayne@69: in order for the decompressor to finish the block before the empty fixed jpayne@69: codes block. jpayne@69: jpayne@69: If flush is set to Z_BLOCK, a deflate block is completed and emitted, as jpayne@69: for Z_SYNC_FLUSH, but the output is not aligned on a byte boundary, and up to jpayne@69: seven bits of the current block are held to be written as the next byte after jpayne@69: the next deflate block is completed. In this case, the decompressor may not jpayne@69: be provided enough bits at this point in order to complete decompression of jpayne@69: the data provided so far to the compressor. It may need to wait for the next jpayne@69: block to be emitted. This is for advanced applications that need to control jpayne@69: the emission of deflate blocks. jpayne@69: jpayne@69: If flush is set to Z_FULL_FLUSH, all output is flushed as with jpayne@69: Z_SYNC_FLUSH, and the compression state is reset so that decompression can jpayne@69: restart from this point if previous compressed data has been damaged or if jpayne@69: random access is desired. Using Z_FULL_FLUSH too often can seriously degrade jpayne@69: compression. jpayne@69: jpayne@69: If deflate returns with avail_out == 0, this function must be called again jpayne@69: with the same value of the flush parameter and more output space (updated jpayne@69: avail_out), until the flush is complete (deflate returns with non-zero jpayne@69: avail_out). In the case of a Z_FULL_FLUSH or Z_SYNC_FLUSH, make sure that jpayne@69: avail_out is greater than six to avoid repeated flush markers due to jpayne@69: avail_out == 0 on return. jpayne@69: jpayne@69: If the parameter flush is set to Z_FINISH, pending input is processed, jpayne@69: pending output is flushed and deflate returns with Z_STREAM_END if there was jpayne@69: enough output space. If deflate returns with Z_OK or Z_BUF_ERROR, this jpayne@69: function must be called again with Z_FINISH and more output space (updated jpayne@69: avail_out) but no more input data, until it returns with Z_STREAM_END or an jpayne@69: error. After deflate has returned Z_STREAM_END, the only possible operations jpayne@69: on the stream are deflateReset or deflateEnd. jpayne@69: jpayne@69: Z_FINISH can be used in the first deflate call after deflateInit if all the jpayne@69: compression is to be done in a single step. In order to complete in one jpayne@69: call, avail_out must be at least the value returned by deflateBound (see jpayne@69: below). Then deflate is guaranteed to return Z_STREAM_END. If not enough jpayne@69: output space is provided, deflate will not return Z_STREAM_END, and it must jpayne@69: be called again as described above. jpayne@69: jpayne@69: deflate() sets strm->adler to the Adler-32 checksum of all input read jpayne@69: so far (that is, total_in bytes). If a gzip stream is being generated, then jpayne@69: strm->adler will be the CRC-32 checksum of the input read so far. (See jpayne@69: deflateInit2 below.) jpayne@69: jpayne@69: deflate() may update strm->data_type if it can make a good guess about jpayne@69: the input data type (Z_BINARY or Z_TEXT). If in doubt, the data is jpayne@69: considered binary. This field is only for information purposes and does not jpayne@69: affect the compression algorithm in any manner. jpayne@69: jpayne@69: deflate() returns Z_OK if some progress has been made (more input jpayne@69: processed or more output produced), Z_STREAM_END if all input has been jpayne@69: consumed and all output has been produced (only when flush is set to jpayne@69: Z_FINISH), Z_STREAM_ERROR if the stream state was inconsistent (for example jpayne@69: if next_in or next_out was Z_NULL or the state was inadvertently written over jpayne@69: by the application), or Z_BUF_ERROR if no progress is possible (for example jpayne@69: avail_in or avail_out was zero). Note that Z_BUF_ERROR is not fatal, and jpayne@69: deflate() can be called again with more input and more output space to jpayne@69: continue compressing. jpayne@69: */ jpayne@69: jpayne@69: jpayne@69: ZEXTERN int ZEXPORT deflateEnd OF((z_streamp strm)); jpayne@69: /* jpayne@69: All dynamically allocated data structures for this stream are freed. jpayne@69: This function discards any unprocessed input and does not flush any pending jpayne@69: output. jpayne@69: jpayne@69: deflateEnd returns Z_OK if success, Z_STREAM_ERROR if the jpayne@69: stream state was inconsistent, Z_DATA_ERROR if the stream was freed jpayne@69: prematurely (some input or output was discarded). In the error case, msg jpayne@69: may be set but then points to a static string (which must not be jpayne@69: deallocated). jpayne@69: */ jpayne@69: jpayne@69: jpayne@69: /* jpayne@69: ZEXTERN int ZEXPORT inflateInit OF((z_streamp strm)); jpayne@69: jpayne@69: Initializes the internal stream state for decompression. The fields jpayne@69: next_in, avail_in, zalloc, zfree and opaque must be initialized before by jpayne@69: the caller. In the current version of inflate, the provided input is not jpayne@69: read or consumed. The allocation of a sliding window will be deferred to jpayne@69: the first call of inflate (if the decompression does not complete on the jpayne@69: first call). If zalloc and zfree are set to Z_NULL, inflateInit updates jpayne@69: them to use default allocation functions. jpayne@69: jpayne@69: inflateInit returns Z_OK if success, Z_MEM_ERROR if there was not enough jpayne@69: memory, Z_VERSION_ERROR if the zlib library version is incompatible with the jpayne@69: version assumed by the caller, or Z_STREAM_ERROR if the parameters are jpayne@69: invalid, such as a null pointer to the structure. msg is set to null if jpayne@69: there is no error message. inflateInit does not perform any decompression. jpayne@69: Actual decompression will be done by inflate(). So next_in, and avail_in, jpayne@69: next_out, and avail_out are unused and unchanged. The current jpayne@69: implementation of inflateInit() does not process any header information -- jpayne@69: that is deferred until inflate() is called. jpayne@69: */ jpayne@69: jpayne@69: jpayne@69: ZEXTERN int ZEXPORT inflate OF((z_streamp strm, int flush)); jpayne@69: /* jpayne@69: inflate decompresses as much data as possible, and stops when the input jpayne@69: buffer becomes empty or the output buffer becomes full. It may introduce jpayne@69: some output latency (reading input without producing any output) except when jpayne@69: forced to flush. jpayne@69: jpayne@69: The detailed semantics are as follows. inflate performs one or both of the jpayne@69: following actions: jpayne@69: jpayne@69: - Decompress more input starting at next_in and update next_in and avail_in jpayne@69: accordingly. If not all input can be processed (because there is not jpayne@69: enough room in the output buffer), then next_in and avail_in are updated jpayne@69: accordingly, and processing will resume at this point for the next call of jpayne@69: inflate(). jpayne@69: jpayne@69: - Generate more output starting at next_out and update next_out and avail_out jpayne@69: accordingly. inflate() provides as much output as possible, until there is jpayne@69: no more input data or no more space in the output buffer (see below about jpayne@69: the flush parameter). jpayne@69: jpayne@69: Before the call of inflate(), the application should ensure that at least jpayne@69: one of the actions is possible, by providing more input and/or consuming more jpayne@69: output, and updating the next_* and avail_* values accordingly. If the jpayne@69: caller of inflate() does not provide both available input and available jpayne@69: output space, it is possible that there will be no progress made. The jpayne@69: application can consume the uncompressed output when it wants, for example jpayne@69: when the output buffer is full (avail_out == 0), or after each call of jpayne@69: inflate(). If inflate returns Z_OK and with zero avail_out, it must be jpayne@69: called again after making room in the output buffer because there might be jpayne@69: more output pending. jpayne@69: jpayne@69: The flush parameter of inflate() can be Z_NO_FLUSH, Z_SYNC_FLUSH, Z_FINISH, jpayne@69: Z_BLOCK, or Z_TREES. Z_SYNC_FLUSH requests that inflate() flush as much jpayne@69: output as possible to the output buffer. Z_BLOCK requests that inflate() jpayne@69: stop if and when it gets to the next deflate block boundary. When decoding jpayne@69: the zlib or gzip format, this will cause inflate() to return immediately jpayne@69: after the header and before the first block. When doing a raw inflate, jpayne@69: inflate() will go ahead and process the first block, and will return when it jpayne@69: gets to the end of that block, or when it runs out of data. jpayne@69: jpayne@69: The Z_BLOCK option assists in appending to or combining deflate streams. jpayne@69: To assist in this, on return inflate() always sets strm->data_type to the jpayne@69: number of unused bits in the last byte taken from strm->next_in, plus 64 if jpayne@69: inflate() is currently decoding the last block in the deflate stream, plus jpayne@69: 128 if inflate() returned immediately after decoding an end-of-block code or jpayne@69: decoding the complete header up to just before the first byte of the deflate jpayne@69: stream. The end-of-block will not be indicated until all of the uncompressed jpayne@69: data from that block has been written to strm->next_out. The number of jpayne@69: unused bits may in general be greater than seven, except when bit 7 of jpayne@69: data_type is set, in which case the number of unused bits will be less than jpayne@69: eight. data_type is set as noted here every time inflate() returns for all jpayne@69: flush options, and so can be used to determine the amount of currently jpayne@69: consumed input in bits. jpayne@69: jpayne@69: The Z_TREES option behaves as Z_BLOCK does, but it also returns when the jpayne@69: end of each deflate block header is reached, before any actual data in that jpayne@69: block is decoded. This allows the caller to determine the length of the jpayne@69: deflate block header for later use in random access within a deflate block. jpayne@69: 256 is added to the value of strm->data_type when inflate() returns jpayne@69: immediately after reaching the end of the deflate block header. jpayne@69: jpayne@69: inflate() should normally be called until it returns Z_STREAM_END or an jpayne@69: error. However if all decompression is to be performed in a single step (a jpayne@69: single call of inflate), the parameter flush should be set to Z_FINISH. In jpayne@69: this case all pending input is processed and all pending output is flushed; jpayne@69: avail_out must be large enough to hold all of the uncompressed data for the jpayne@69: operation to complete. (The size of the uncompressed data may have been jpayne@69: saved by the compressor for this purpose.) The use of Z_FINISH is not jpayne@69: required to perform an inflation in one step. However it may be used to jpayne@69: inform inflate that a faster approach can be used for the single inflate() jpayne@69: call. Z_FINISH also informs inflate to not maintain a sliding window if the jpayne@69: stream completes, which reduces inflate's memory footprint. If the stream jpayne@69: does not complete, either because not all of the stream is provided or not jpayne@69: enough output space is provided, then a sliding window will be allocated and jpayne@69: inflate() can be called again to continue the operation as if Z_NO_FLUSH had jpayne@69: been used. jpayne@69: jpayne@69: In this implementation, inflate() always flushes as much output as jpayne@69: possible to the output buffer, and always uses the faster approach on the jpayne@69: first call. So the effects of the flush parameter in this implementation are jpayne@69: on the return value of inflate() as noted below, when inflate() returns early jpayne@69: when Z_BLOCK or Z_TREES is used, and when inflate() avoids the allocation of jpayne@69: memory for a sliding window when Z_FINISH is used. jpayne@69: jpayne@69: If a preset dictionary is needed after this call (see inflateSetDictionary jpayne@69: below), inflate sets strm->adler to the Adler-32 checksum of the dictionary jpayne@69: chosen by the compressor and returns Z_NEED_DICT; otherwise it sets jpayne@69: strm->adler to the Adler-32 checksum of all output produced so far (that is, jpayne@69: total_out bytes) and returns Z_OK, Z_STREAM_END or an error code as described jpayne@69: below. At the end of the stream, inflate() checks that its computed Adler-32 jpayne@69: checksum is equal to that saved by the compressor and returns Z_STREAM_END jpayne@69: only if the checksum is correct. jpayne@69: jpayne@69: inflate() can decompress and check either zlib-wrapped or gzip-wrapped jpayne@69: deflate data. The header type is detected automatically, if requested when jpayne@69: initializing with inflateInit2(). Any information contained in the gzip jpayne@69: header is not retained unless inflateGetHeader() is used. When processing jpayne@69: gzip-wrapped deflate data, strm->adler32 is set to the CRC-32 of the output jpayne@69: produced so far. The CRC-32 is checked against the gzip trailer, as is the jpayne@69: uncompressed length, modulo 2^32. jpayne@69: jpayne@69: inflate() returns Z_OK if some progress has been made (more input processed jpayne@69: or more output produced), Z_STREAM_END if the end of the compressed data has jpayne@69: been reached and all uncompressed output has been produced, Z_NEED_DICT if a jpayne@69: preset dictionary is needed at this point, Z_DATA_ERROR if the input data was jpayne@69: corrupted (input stream not conforming to the zlib format or incorrect check jpayne@69: value, in which case strm->msg points to a string with a more specific jpayne@69: error), Z_STREAM_ERROR if the stream structure was inconsistent (for example jpayne@69: next_in or next_out was Z_NULL, or the state was inadvertently written over jpayne@69: by the application), Z_MEM_ERROR if there was not enough memory, Z_BUF_ERROR jpayne@69: if no progress was possible or if there was not enough room in the output jpayne@69: buffer when Z_FINISH is used. Note that Z_BUF_ERROR is not fatal, and jpayne@69: inflate() can be called again with more input and more output space to jpayne@69: continue decompressing. If Z_DATA_ERROR is returned, the application may jpayne@69: then call inflateSync() to look for a good compression block if a partial jpayne@69: recovery of the data is to be attempted. jpayne@69: */ jpayne@69: jpayne@69: jpayne@69: ZEXTERN int ZEXPORT inflateEnd OF((z_streamp strm)); jpayne@69: /* jpayne@69: All dynamically allocated data structures for this stream are freed. jpayne@69: This function discards any unprocessed input and does not flush any pending jpayne@69: output. jpayne@69: jpayne@69: inflateEnd returns Z_OK if success, or Z_STREAM_ERROR if the stream state jpayne@69: was inconsistent. jpayne@69: */ jpayne@69: jpayne@69: jpayne@69: /* Advanced functions */ jpayne@69: jpayne@69: /* jpayne@69: The following functions are needed only in some special applications. jpayne@69: */ jpayne@69: jpayne@69: /* jpayne@69: ZEXTERN int ZEXPORT deflateInit2 OF((z_streamp strm, jpayne@69: int level, jpayne@69: int method, jpayne@69: int windowBits, jpayne@69: int memLevel, jpayne@69: int strategy)); jpayne@69: jpayne@69: This is another version of deflateInit with more compression options. The jpayne@69: fields zalloc, zfree and opaque must be initialized before by the caller. jpayne@69: jpayne@69: The method parameter is the compression method. It must be Z_DEFLATED in jpayne@69: this version of the library. jpayne@69: jpayne@69: The windowBits parameter is the base two logarithm of the window size jpayne@69: (the size of the history buffer). It should be in the range 8..15 for this jpayne@69: version of the library. Larger values of this parameter result in better jpayne@69: compression at the expense of memory usage. The default value is 15 if jpayne@69: deflateInit is used instead. jpayne@69: jpayne@69: For the current implementation of deflate(), a windowBits value of 8 (a jpayne@69: window size of 256 bytes) is not supported. As a result, a request for 8 jpayne@69: will result in 9 (a 512-byte window). In that case, providing 8 to jpayne@69: inflateInit2() will result in an error when the zlib header with 9 is jpayne@69: checked against the initialization of inflate(). The remedy is to not use 8 jpayne@69: with deflateInit2() with this initialization, or at least in that case use 9 jpayne@69: with inflateInit2(). jpayne@69: jpayne@69: windowBits can also be -8..-15 for raw deflate. In this case, -windowBits jpayne@69: determines the window size. deflate() will then generate raw deflate data jpayne@69: with no zlib header or trailer, and will not compute a check value. jpayne@69: jpayne@69: windowBits can also be greater than 15 for optional gzip encoding. Add jpayne@69: 16 to windowBits to write a simple gzip header and trailer around the jpayne@69: compressed data instead of a zlib wrapper. The gzip header will have no jpayne@69: file name, no extra data, no comment, no modification time (set to zero), no jpayne@69: header crc, and the operating system will be set to the appropriate value, jpayne@69: if the operating system was determined at compile time. If a gzip stream is jpayne@69: being written, strm->adler is a CRC-32 instead of an Adler-32. jpayne@69: jpayne@69: For raw deflate or gzip encoding, a request for a 256-byte window is jpayne@69: rejected as invalid, since only the zlib header provides a means of jpayne@69: transmitting the window size to the decompressor. jpayne@69: jpayne@69: The memLevel parameter specifies how much memory should be allocated jpayne@69: for the internal compression state. memLevel=1 uses minimum memory but is jpayne@69: slow and reduces compression ratio; memLevel=9 uses maximum memory for jpayne@69: optimal speed. The default value is 8. See zconf.h for total memory usage jpayne@69: as a function of windowBits and memLevel. jpayne@69: jpayne@69: The strategy parameter is used to tune the compression algorithm. Use the jpayne@69: value Z_DEFAULT_STRATEGY for normal data, Z_FILTERED for data produced by a jpayne@69: filter (or predictor), Z_HUFFMAN_ONLY to force Huffman encoding only (no jpayne@69: string match), or Z_RLE to limit match distances to one (run-length jpayne@69: encoding). Filtered data consists mostly of small values with a somewhat jpayne@69: random distribution. In this case, the compression algorithm is tuned to jpayne@69: compress them better. The effect of Z_FILTERED is to force more Huffman jpayne@69: coding and less string matching; it is somewhat intermediate between jpayne@69: Z_DEFAULT_STRATEGY and Z_HUFFMAN_ONLY. Z_RLE is designed to be almost as jpayne@69: fast as Z_HUFFMAN_ONLY, but give better compression for PNG image data. The jpayne@69: strategy parameter only affects the compression ratio but not the jpayne@69: correctness of the compressed output even if it is not set appropriately. jpayne@69: Z_FIXED prevents the use of dynamic Huffman codes, allowing for a simpler jpayne@69: decoder for special applications. jpayne@69: jpayne@69: deflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough jpayne@69: memory, Z_STREAM_ERROR if any parameter is invalid (such as an invalid jpayne@69: method), or Z_VERSION_ERROR if the zlib library version (zlib_version) is jpayne@69: incompatible with the version assumed by the caller (ZLIB_VERSION). msg is jpayne@69: set to null if there is no error message. deflateInit2 does not perform any jpayne@69: compression: this will be done by deflate(). jpayne@69: */ jpayne@69: jpayne@69: ZEXTERN int ZEXPORT deflateSetDictionary OF((z_streamp strm, jpayne@69: const Bytef *dictionary, jpayne@69: uInt dictLength)); jpayne@69: /* jpayne@69: Initializes the compression dictionary from the given byte sequence jpayne@69: without producing any compressed output. When using the zlib format, this jpayne@69: function must be called immediately after deflateInit, deflateInit2 or jpayne@69: deflateReset, and before any call of deflate. When doing raw deflate, this jpayne@69: function must be called either before any call of deflate, or immediately jpayne@69: after the completion of a deflate block, i.e. after all input has been jpayne@69: consumed and all output has been delivered when using any of the flush jpayne@69: options Z_BLOCK, Z_PARTIAL_FLUSH, Z_SYNC_FLUSH, or Z_FULL_FLUSH. The jpayne@69: compressor and decompressor must use exactly the same dictionary (see jpayne@69: inflateSetDictionary). jpayne@69: jpayne@69: The dictionary should consist of strings (byte sequences) that are likely jpayne@69: to be encountered later in the data to be compressed, with the most commonly jpayne@69: used strings preferably put towards the end of the dictionary. Using a jpayne@69: dictionary is most useful when the data to be compressed is short and can be jpayne@69: predicted with good accuracy; the data can then be compressed better than jpayne@69: with the default empty dictionary. jpayne@69: jpayne@69: Depending on the size of the compression data structures selected by jpayne@69: deflateInit or deflateInit2, a part of the dictionary may in effect be jpayne@69: discarded, for example if the dictionary is larger than the window size jpayne@69: provided in deflateInit or deflateInit2. Thus the strings most likely to be jpayne@69: useful should be put at the end of the dictionary, not at the front. In jpayne@69: addition, the current implementation of deflate will use at most the window jpayne@69: size minus 262 bytes of the provided dictionary. jpayne@69: jpayne@69: Upon return of this function, strm->adler is set to the Adler-32 value jpayne@69: of the dictionary; the decompressor may later use this value to determine jpayne@69: which dictionary has been used by the compressor. (The Adler-32 value jpayne@69: applies to the whole dictionary even if only a subset of the dictionary is jpayne@69: actually used by the compressor.) If a raw deflate was requested, then the jpayne@69: Adler-32 value is not computed and strm->adler is not set. jpayne@69: jpayne@69: deflateSetDictionary returns Z_OK if success, or Z_STREAM_ERROR if a jpayne@69: parameter is invalid (e.g. dictionary being Z_NULL) or the stream state is jpayne@69: inconsistent (for example if deflate has already been called for this stream jpayne@69: or if not at a block boundary for raw deflate). deflateSetDictionary does jpayne@69: not perform any compression: this will be done by deflate(). jpayne@69: */ jpayne@69: jpayne@69: ZEXTERN int ZEXPORT deflateGetDictionary OF((z_streamp strm, jpayne@69: Bytef *dictionary, jpayne@69: uInt *dictLength)); jpayne@69: /* jpayne@69: Returns the sliding dictionary being maintained by deflate. dictLength is jpayne@69: set to the number of bytes in the dictionary, and that many bytes are copied jpayne@69: to dictionary. dictionary must have enough space, where 32768 bytes is jpayne@69: always enough. If deflateGetDictionary() is called with dictionary equal to jpayne@69: Z_NULL, then only the dictionary length is returned, and nothing is copied. jpayne@69: Similarly, if dictLength is Z_NULL, then it is not set. jpayne@69: jpayne@69: deflateGetDictionary() may return a length less than the window size, even jpayne@69: when more than the window size in input has been provided. It may return up jpayne@69: to 258 bytes less in that case, due to how zlib's implementation of deflate jpayne@69: manages the sliding window and lookahead for matches, where matches can be jpayne@69: up to 258 bytes long. If the application needs the last window-size bytes of jpayne@69: input, then that would need to be saved by the application outside of zlib. jpayne@69: jpayne@69: deflateGetDictionary returns Z_OK on success, or Z_STREAM_ERROR if the jpayne@69: stream state is inconsistent. jpayne@69: */ jpayne@69: jpayne@69: ZEXTERN int ZEXPORT deflateCopy OF((z_streamp dest, jpayne@69: z_streamp source)); jpayne@69: /* jpayne@69: Sets the destination stream as a complete copy of the source stream. jpayne@69: jpayne@69: This function can be useful when several compression strategies will be jpayne@69: tried, for example when there are several ways of pre-processing the input jpayne@69: data with a filter. The streams that will be discarded should then be freed jpayne@69: by calling deflateEnd. Note that deflateCopy duplicates the internal jpayne@69: compression state which can be quite large, so this strategy is slow and can jpayne@69: consume lots of memory. jpayne@69: jpayne@69: deflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not jpayne@69: enough memory, Z_STREAM_ERROR if the source stream state was inconsistent jpayne@69: (such as zalloc being Z_NULL). msg is left unchanged in both source and jpayne@69: destination. jpayne@69: */ jpayne@69: jpayne@69: ZEXTERN int ZEXPORT deflateReset OF((z_streamp strm)); jpayne@69: /* jpayne@69: This function is equivalent to deflateEnd followed by deflateInit, but jpayne@69: does not free and reallocate the internal compression state. The stream jpayne@69: will leave the compression level and any other attributes that may have been jpayne@69: set unchanged. jpayne@69: jpayne@69: deflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source jpayne@69: stream state was inconsistent (such as zalloc or state being Z_NULL). jpayne@69: */ jpayne@69: jpayne@69: ZEXTERN int ZEXPORT deflateParams OF((z_streamp strm, jpayne@69: int level, jpayne@69: int strategy)); jpayne@69: /* jpayne@69: Dynamically update the compression level and compression strategy. The jpayne@69: interpretation of level and strategy is as in deflateInit2(). This can be jpayne@69: used to switch between compression and straight copy of the input data, or jpayne@69: to switch to a different kind of input data requiring a different strategy. jpayne@69: If the compression approach (which is a function of the level) or the jpayne@69: strategy is changed, and if there have been any deflate() calls since the jpayne@69: state was initialized or reset, then the input available so far is jpayne@69: compressed with the old level and strategy using deflate(strm, Z_BLOCK). jpayne@69: There are three approaches for the compression levels 0, 1..3, and 4..9 jpayne@69: respectively. The new level and strategy will take effect at the next call jpayne@69: of deflate(). jpayne@69: jpayne@69: If a deflate(strm, Z_BLOCK) is performed by deflateParams(), and it does jpayne@69: not have enough output space to complete, then the parameter change will not jpayne@69: take effect. In this case, deflateParams() can be called again with the jpayne@69: same parameters and more output space to try again. jpayne@69: jpayne@69: In order to assure a change in the parameters on the first try, the jpayne@69: deflate stream should be flushed using deflate() with Z_BLOCK or other flush jpayne@69: request until strm.avail_out is not zero, before calling deflateParams(). jpayne@69: Then no more input data should be provided before the deflateParams() call. jpayne@69: If this is done, the old level and strategy will be applied to the data jpayne@69: compressed before deflateParams(), and the new level and strategy will be jpayne@69: applied to the the data compressed after deflateParams(). jpayne@69: jpayne@69: deflateParams returns Z_OK on success, Z_STREAM_ERROR if the source stream jpayne@69: state was inconsistent or if a parameter was invalid, or Z_BUF_ERROR if jpayne@69: there was not enough output space to complete the compression of the jpayne@69: available input data before a change in the strategy or approach. Note that jpayne@69: in the case of a Z_BUF_ERROR, the parameters are not changed. A return jpayne@69: value of Z_BUF_ERROR is not fatal, in which case deflateParams() can be jpayne@69: retried with more output space. jpayne@69: */ jpayne@69: jpayne@69: ZEXTERN int ZEXPORT deflateTune OF((z_streamp strm, jpayne@69: int good_length, jpayne@69: int max_lazy, jpayne@69: int nice_length, jpayne@69: int max_chain)); jpayne@69: /* jpayne@69: Fine tune deflate's internal compression parameters. This should only be jpayne@69: used by someone who understands the algorithm used by zlib's deflate for jpayne@69: searching for the best matching string, and even then only by the most jpayne@69: fanatic optimizer trying to squeeze out the last compressed bit for their jpayne@69: specific input data. Read the deflate.c source code for the meaning of the jpayne@69: max_lazy, good_length, nice_length, and max_chain parameters. jpayne@69: jpayne@69: deflateTune() can be called after deflateInit() or deflateInit2(), and jpayne@69: returns Z_OK on success, or Z_STREAM_ERROR for an invalid deflate stream. jpayne@69: */ jpayne@69: jpayne@69: ZEXTERN uLong ZEXPORT deflateBound OF((z_streamp strm, jpayne@69: uLong sourceLen)); jpayne@69: /* jpayne@69: deflateBound() returns an upper bound on the compressed size after jpayne@69: deflation of sourceLen bytes. It must be called after deflateInit() or jpayne@69: deflateInit2(), and after deflateSetHeader(), if used. This would be used jpayne@69: to allocate an output buffer for deflation in a single pass, and so would be jpayne@69: called before deflate(). If that first deflate() call is provided the jpayne@69: sourceLen input bytes, an output buffer allocated to the size returned by jpayne@69: deflateBound(), and the flush value Z_FINISH, then deflate() is guaranteed jpayne@69: to return Z_STREAM_END. Note that it is possible for the compressed size to jpayne@69: be larger than the value returned by deflateBound() if flush options other jpayne@69: than Z_FINISH or Z_NO_FLUSH are used. jpayne@69: */ jpayne@69: jpayne@69: ZEXTERN int ZEXPORT deflatePending OF((z_streamp strm, jpayne@69: unsigned *pending, jpayne@69: int *bits)); jpayne@69: /* jpayne@69: deflatePending() returns the number of bytes and bits of output that have jpayne@69: been generated, but not yet provided in the available output. The bytes not jpayne@69: provided would be due to the available output space having being consumed. jpayne@69: The number of bits of output not provided are between 0 and 7, where they jpayne@69: await more bits to join them in order to fill out a full byte. If pending jpayne@69: or bits are Z_NULL, then those values are not set. jpayne@69: jpayne@69: deflatePending returns Z_OK if success, or Z_STREAM_ERROR if the source jpayne@69: stream state was inconsistent. jpayne@69: */ jpayne@69: jpayne@69: ZEXTERN int ZEXPORT deflatePrime OF((z_streamp strm, jpayne@69: int bits, jpayne@69: int value)); jpayne@69: /* jpayne@69: deflatePrime() inserts bits in the deflate output stream. The intent jpayne@69: is that this function is used to start off the deflate output with the bits jpayne@69: leftover from a previous deflate stream when appending to it. As such, this jpayne@69: function can only be used for raw deflate, and must be used before the first jpayne@69: deflate() call after a deflateInit2() or deflateReset(). bits must be less jpayne@69: than or equal to 16, and that many of the least significant bits of value jpayne@69: will be inserted in the output. jpayne@69: jpayne@69: deflatePrime returns Z_OK if success, Z_BUF_ERROR if there was not enough jpayne@69: room in the internal buffer to insert the bits, or Z_STREAM_ERROR if the jpayne@69: source stream state was inconsistent. jpayne@69: */ jpayne@69: jpayne@69: ZEXTERN int ZEXPORT deflateSetHeader OF((z_streamp strm, jpayne@69: gz_headerp head)); jpayne@69: /* jpayne@69: deflateSetHeader() provides gzip header information for when a gzip jpayne@69: stream is requested by deflateInit2(). deflateSetHeader() may be called jpayne@69: after deflateInit2() or deflateReset() and before the first call of jpayne@69: deflate(). The text, time, os, extra field, name, and comment information jpayne@69: in the provided gz_header structure are written to the gzip header (xflag is jpayne@69: ignored -- the extra flags are set according to the compression level). The jpayne@69: caller must assure that, if not Z_NULL, name and comment are terminated with jpayne@69: a zero byte, and that if extra is not Z_NULL, that extra_len bytes are jpayne@69: available there. If hcrc is true, a gzip header crc is included. Note that jpayne@69: the current versions of the command-line version of gzip (up through version jpayne@69: 1.3.x) do not support header crc's, and will report that it is a "multi-part jpayne@69: gzip file" and give up. jpayne@69: jpayne@69: If deflateSetHeader is not used, the default gzip header has text false, jpayne@69: the time set to zero, and os set to 255, with no extra, name, or comment jpayne@69: fields. The gzip header is returned to the default state by deflateReset(). jpayne@69: jpayne@69: deflateSetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source jpayne@69: stream state was inconsistent. jpayne@69: */ jpayne@69: jpayne@69: /* jpayne@69: ZEXTERN int ZEXPORT inflateInit2 OF((z_streamp strm, jpayne@69: int windowBits)); jpayne@69: jpayne@69: This is another version of inflateInit with an extra parameter. The jpayne@69: fields next_in, avail_in, zalloc, zfree and opaque must be initialized jpayne@69: before by the caller. jpayne@69: jpayne@69: The windowBits parameter is the base two logarithm of the maximum window jpayne@69: size (the size of the history buffer). It should be in the range 8..15 for jpayne@69: this version of the library. The default value is 15 if inflateInit is used jpayne@69: instead. windowBits must be greater than or equal to the windowBits value jpayne@69: provided to deflateInit2() while compressing, or it must be equal to 15 if jpayne@69: deflateInit2() was not used. If a compressed stream with a larger window jpayne@69: size is given as input, inflate() will return with the error code jpayne@69: Z_DATA_ERROR instead of trying to allocate a larger window. jpayne@69: jpayne@69: windowBits can also be zero to request that inflate use the window size in jpayne@69: the zlib header of the compressed stream. jpayne@69: jpayne@69: windowBits can also be -8..-15 for raw inflate. In this case, -windowBits jpayne@69: determines the window size. inflate() will then process raw deflate data, jpayne@69: not looking for a zlib or gzip header, not generating a check value, and not jpayne@69: looking for any check values for comparison at the end of the stream. This jpayne@69: is for use with other formats that use the deflate compressed data format jpayne@69: such as zip. Those formats provide their own check values. If a custom jpayne@69: format is developed using the raw deflate format for compressed data, it is jpayne@69: recommended that a check value such as an Adler-32 or a CRC-32 be applied to jpayne@69: the uncompressed data as is done in the zlib, gzip, and zip formats. For jpayne@69: most applications, the zlib format should be used as is. Note that comments jpayne@69: above on the use in deflateInit2() applies to the magnitude of windowBits. jpayne@69: jpayne@69: windowBits can also be greater than 15 for optional gzip decoding. Add jpayne@69: 32 to windowBits to enable zlib and gzip decoding with automatic header jpayne@69: detection, or add 16 to decode only the gzip format (the zlib format will jpayne@69: return a Z_DATA_ERROR). If a gzip stream is being decoded, strm->adler is a jpayne@69: CRC-32 instead of an Adler-32. Unlike the gunzip utility and gzread() (see jpayne@69: below), inflate() will *not* automatically decode concatenated gzip members. jpayne@69: inflate() will return Z_STREAM_END at the end of the gzip member. The state jpayne@69: would need to be reset to continue decoding a subsequent gzip member. This jpayne@69: *must* be done if there is more data after a gzip member, in order for the jpayne@69: decompression to be compliant with the gzip standard (RFC 1952). jpayne@69: jpayne@69: inflateInit2 returns Z_OK if success, Z_MEM_ERROR if there was not enough jpayne@69: memory, Z_VERSION_ERROR if the zlib library version is incompatible with the jpayne@69: version assumed by the caller, or Z_STREAM_ERROR if the parameters are jpayne@69: invalid, such as a null pointer to the structure. msg is set to null if jpayne@69: there is no error message. inflateInit2 does not perform any decompression jpayne@69: apart from possibly reading the zlib header if present: actual decompression jpayne@69: will be done by inflate(). (So next_in and avail_in may be modified, but jpayne@69: next_out and avail_out are unused and unchanged.) The current implementation jpayne@69: of inflateInit2() does not process any header information -- that is jpayne@69: deferred until inflate() is called. jpayne@69: */ jpayne@69: jpayne@69: ZEXTERN int ZEXPORT inflateSetDictionary OF((z_streamp strm, jpayne@69: const Bytef *dictionary, jpayne@69: uInt dictLength)); jpayne@69: /* jpayne@69: Initializes the decompression dictionary from the given uncompressed byte jpayne@69: sequence. This function must be called immediately after a call of inflate, jpayne@69: if that call returned Z_NEED_DICT. The dictionary chosen by the compressor jpayne@69: can be determined from the Adler-32 value returned by that call of inflate. jpayne@69: The compressor and decompressor must use exactly the same dictionary (see jpayne@69: deflateSetDictionary). For raw inflate, this function can be called at any jpayne@69: time to set the dictionary. If the provided dictionary is smaller than the jpayne@69: window and there is already data in the window, then the provided dictionary jpayne@69: will amend what's there. The application must insure that the dictionary jpayne@69: that was used for compression is provided. jpayne@69: jpayne@69: inflateSetDictionary returns Z_OK if success, Z_STREAM_ERROR if a jpayne@69: parameter is invalid (e.g. dictionary being Z_NULL) or the stream state is jpayne@69: inconsistent, Z_DATA_ERROR if the given dictionary doesn't match the jpayne@69: expected one (incorrect Adler-32 value). inflateSetDictionary does not jpayne@69: perform any decompression: this will be done by subsequent calls of jpayne@69: inflate(). jpayne@69: */ jpayne@69: jpayne@69: ZEXTERN int ZEXPORT inflateGetDictionary OF((z_streamp strm, jpayne@69: Bytef *dictionary, jpayne@69: uInt *dictLength)); jpayne@69: /* jpayne@69: Returns the sliding dictionary being maintained by inflate. dictLength is jpayne@69: set to the number of bytes in the dictionary, and that many bytes are copied jpayne@69: to dictionary. dictionary must have enough space, where 32768 bytes is jpayne@69: always enough. If inflateGetDictionary() is called with dictionary equal to jpayne@69: Z_NULL, then only the dictionary length is returned, and nothing is copied. jpayne@69: Similarly, if dictLength is Z_NULL, then it is not set. jpayne@69: jpayne@69: inflateGetDictionary returns Z_OK on success, or Z_STREAM_ERROR if the jpayne@69: stream state is inconsistent. jpayne@69: */ jpayne@69: jpayne@69: ZEXTERN int ZEXPORT inflateSync OF((z_streamp strm)); jpayne@69: /* jpayne@69: Skips invalid compressed data until a possible full flush point (see above jpayne@69: for the description of deflate with Z_FULL_FLUSH) can be found, or until all jpayne@69: available input is skipped. No output is provided. jpayne@69: jpayne@69: inflateSync searches for a 00 00 FF FF pattern in the compressed data. jpayne@69: All full flush points have this pattern, but not all occurrences of this jpayne@69: pattern are full flush points. jpayne@69: jpayne@69: inflateSync returns Z_OK if a possible full flush point has been found, jpayne@69: Z_BUF_ERROR if no more input was provided, Z_DATA_ERROR if no flush point jpayne@69: has been found, or Z_STREAM_ERROR if the stream structure was inconsistent. jpayne@69: In the success case, the application may save the current current value of jpayne@69: total_in which indicates where valid compressed data was found. In the jpayne@69: error case, the application may repeatedly call inflateSync, providing more jpayne@69: input each time, until success or end of the input data. jpayne@69: */ jpayne@69: jpayne@69: ZEXTERN int ZEXPORT inflateCopy OF((z_streamp dest, jpayne@69: z_streamp source)); jpayne@69: /* jpayne@69: Sets the destination stream as a complete copy of the source stream. jpayne@69: jpayne@69: This function can be useful when randomly accessing a large stream. The jpayne@69: first pass through the stream can periodically record the inflate state, jpayne@69: allowing restarting inflate at those points when randomly accessing the jpayne@69: stream. jpayne@69: jpayne@69: inflateCopy returns Z_OK if success, Z_MEM_ERROR if there was not jpayne@69: enough memory, Z_STREAM_ERROR if the source stream state was inconsistent jpayne@69: (such as zalloc being Z_NULL). msg is left unchanged in both source and jpayne@69: destination. jpayne@69: */ jpayne@69: jpayne@69: ZEXTERN int ZEXPORT inflateReset OF((z_streamp strm)); jpayne@69: /* jpayne@69: This function is equivalent to inflateEnd followed by inflateInit, jpayne@69: but does not free and reallocate the internal decompression state. The jpayne@69: stream will keep attributes that may have been set by inflateInit2. jpayne@69: jpayne@69: inflateReset returns Z_OK if success, or Z_STREAM_ERROR if the source jpayne@69: stream state was inconsistent (such as zalloc or state being Z_NULL). jpayne@69: */ jpayne@69: jpayne@69: ZEXTERN int ZEXPORT inflateReset2 OF((z_streamp strm, jpayne@69: int windowBits)); jpayne@69: /* jpayne@69: This function is the same as inflateReset, but it also permits changing jpayne@69: the wrap and window size requests. The windowBits parameter is interpreted jpayne@69: the same as it is for inflateInit2. If the window size is changed, then the jpayne@69: memory allocated for the window is freed, and the window will be reallocated jpayne@69: by inflate() if needed. jpayne@69: jpayne@69: inflateReset2 returns Z_OK if success, or Z_STREAM_ERROR if the source jpayne@69: stream state was inconsistent (such as zalloc or state being Z_NULL), or if jpayne@69: the windowBits parameter is invalid. jpayne@69: */ jpayne@69: jpayne@69: ZEXTERN int ZEXPORT inflatePrime OF((z_streamp strm, jpayne@69: int bits, jpayne@69: int value)); jpayne@69: /* jpayne@69: This function inserts bits in the inflate input stream. The intent is jpayne@69: that this function is used to start inflating at a bit position in the jpayne@69: middle of a byte. The provided bits will be used before any bytes are used jpayne@69: from next_in. This function should only be used with raw inflate, and jpayne@69: should be used before the first inflate() call after inflateInit2() or jpayne@69: inflateReset(). bits must be less than or equal to 16, and that many of the jpayne@69: least significant bits of value will be inserted in the input. jpayne@69: jpayne@69: If bits is negative, then the input stream bit buffer is emptied. Then jpayne@69: inflatePrime() can be called again to put bits in the buffer. This is used jpayne@69: to clear out bits leftover after feeding inflate a block description prior jpayne@69: to feeding inflate codes. jpayne@69: jpayne@69: inflatePrime returns Z_OK if success, or Z_STREAM_ERROR if the source jpayne@69: stream state was inconsistent. jpayne@69: */ jpayne@69: jpayne@69: ZEXTERN long ZEXPORT inflateMark OF((z_streamp strm)); jpayne@69: /* jpayne@69: This function returns two values, one in the lower 16 bits of the return jpayne@69: value, and the other in the remaining upper bits, obtained by shifting the jpayne@69: return value down 16 bits. If the upper value is -1 and the lower value is jpayne@69: zero, then inflate() is currently decoding information outside of a block. jpayne@69: If the upper value is -1 and the lower value is non-zero, then inflate is in jpayne@69: the middle of a stored block, with the lower value equaling the number of jpayne@69: bytes from the input remaining to copy. If the upper value is not -1, then jpayne@69: it is the number of bits back from the current bit position in the input of jpayne@69: the code (literal or length/distance pair) currently being processed. In jpayne@69: that case the lower value is the number of bytes already emitted for that jpayne@69: code. jpayne@69: jpayne@69: A code is being processed if inflate is waiting for more input to complete jpayne@69: decoding of the code, or if it has completed decoding but is waiting for jpayne@69: more output space to write the literal or match data. jpayne@69: jpayne@69: inflateMark() is used to mark locations in the input data for random jpayne@69: access, which may be at bit positions, and to note those cases where the jpayne@69: output of a code may span boundaries of random access blocks. The current jpayne@69: location in the input stream can be determined from avail_in and data_type jpayne@69: as noted in the description for the Z_BLOCK flush parameter for inflate. jpayne@69: jpayne@69: inflateMark returns the value noted above, or -65536 if the provided jpayne@69: source stream state was inconsistent. jpayne@69: */ jpayne@69: jpayne@69: ZEXTERN int ZEXPORT inflateGetHeader OF((z_streamp strm, jpayne@69: gz_headerp head)); jpayne@69: /* jpayne@69: inflateGetHeader() requests that gzip header information be stored in the jpayne@69: provided gz_header structure. inflateGetHeader() may be called after jpayne@69: inflateInit2() or inflateReset(), and before the first call of inflate(). jpayne@69: As inflate() processes the gzip stream, head->done is zero until the header jpayne@69: is completed, at which time head->done is set to one. If a zlib stream is jpayne@69: being decoded, then head->done is set to -1 to indicate that there will be jpayne@69: no gzip header information forthcoming. Note that Z_BLOCK or Z_TREES can be jpayne@69: used to force inflate() to return immediately after header processing is jpayne@69: complete and before any actual data is decompressed. jpayne@69: jpayne@69: The text, time, xflags, and os fields are filled in with the gzip header jpayne@69: contents. hcrc is set to true if there is a header CRC. (The header CRC jpayne@69: was valid if done is set to one.) If extra is not Z_NULL, then extra_max jpayne@69: contains the maximum number of bytes to write to extra. Once done is true, jpayne@69: extra_len contains the actual extra field length, and extra contains the jpayne@69: extra field, or that field truncated if extra_max is less than extra_len. jpayne@69: If name is not Z_NULL, then up to name_max characters are written there, jpayne@69: terminated with a zero unless the length is greater than name_max. If jpayne@69: comment is not Z_NULL, then up to comm_max characters are written there, jpayne@69: terminated with a zero unless the length is greater than comm_max. When any jpayne@69: of extra, name, or comment are not Z_NULL and the respective field is not jpayne@69: present in the header, then that field is set to Z_NULL to signal its jpayne@69: absence. This allows the use of deflateSetHeader() with the returned jpayne@69: structure to duplicate the header. However if those fields are set to jpayne@69: allocated memory, then the application will need to save those pointers jpayne@69: elsewhere so that they can be eventually freed. jpayne@69: jpayne@69: If inflateGetHeader is not used, then the header information is simply jpayne@69: discarded. The header is always checked for validity, including the header jpayne@69: CRC if present. inflateReset() will reset the process to discard the header jpayne@69: information. The application would need to call inflateGetHeader() again to jpayne@69: retrieve the header from the next gzip stream. jpayne@69: jpayne@69: inflateGetHeader returns Z_OK if success, or Z_STREAM_ERROR if the source jpayne@69: stream state was inconsistent. jpayne@69: */ jpayne@69: jpayne@69: /* jpayne@69: ZEXTERN int ZEXPORT inflateBackInit OF((z_streamp strm, int windowBits, jpayne@69: unsigned char FAR *window)); jpayne@69: jpayne@69: Initialize the internal stream state for decompression using inflateBack() jpayne@69: calls. The fields zalloc, zfree and opaque in strm must be initialized jpayne@69: before the call. If zalloc and zfree are Z_NULL, then the default library- jpayne@69: derived memory allocation routines are used. windowBits is the base two jpayne@69: logarithm of the window size, in the range 8..15. window is a caller jpayne@69: supplied buffer of that size. Except for special applications where it is jpayne@69: assured that deflate was used with small window sizes, windowBits must be 15 jpayne@69: and a 32K byte window must be supplied to be able to decompress general jpayne@69: deflate streams. jpayne@69: jpayne@69: See inflateBack() for the usage of these routines. jpayne@69: jpayne@69: inflateBackInit will return Z_OK on success, Z_STREAM_ERROR if any of jpayne@69: the parameters are invalid, Z_MEM_ERROR if the internal state could not be jpayne@69: allocated, or Z_VERSION_ERROR if the version of the library does not match jpayne@69: the version of the header file. jpayne@69: */ jpayne@69: jpayne@69: typedef unsigned (*in_func) OF((void FAR *, jpayne@69: z_const unsigned char FAR * FAR *)); jpayne@69: typedef int (*out_func) OF((void FAR *, unsigned char FAR *, unsigned)); jpayne@69: jpayne@69: ZEXTERN int ZEXPORT inflateBack OF((z_streamp strm, jpayne@69: in_func in, void FAR *in_desc, jpayne@69: out_func out, void FAR *out_desc)); jpayne@69: /* jpayne@69: inflateBack() does a raw inflate with a single call using a call-back jpayne@69: interface for input and output. This is potentially more efficient than jpayne@69: inflate() for file i/o applications, in that it avoids copying between the jpayne@69: output and the sliding window by simply making the window itself the output jpayne@69: buffer. inflate() can be faster on modern CPUs when used with large jpayne@69: buffers. inflateBack() trusts the application to not change the output jpayne@69: buffer passed by the output function, at least until inflateBack() returns. jpayne@69: jpayne@69: inflateBackInit() must be called first to allocate the internal state jpayne@69: and to initialize the state with the user-provided window buffer. jpayne@69: inflateBack() may then be used multiple times to inflate a complete, raw jpayne@69: deflate stream with each call. inflateBackEnd() is then called to free the jpayne@69: allocated state. jpayne@69: jpayne@69: A raw deflate stream is one with no zlib or gzip header or trailer. jpayne@69: This routine would normally be used in a utility that reads zip or gzip jpayne@69: files and writes out uncompressed files. The utility would decode the jpayne@69: header and process the trailer on its own, hence this routine expects only jpayne@69: the raw deflate stream to decompress. This is different from the default jpayne@69: behavior of inflate(), which expects a zlib header and trailer around the jpayne@69: deflate stream. jpayne@69: jpayne@69: inflateBack() uses two subroutines supplied by the caller that are then jpayne@69: called by inflateBack() for input and output. inflateBack() calls those jpayne@69: routines until it reads a complete deflate stream and writes out all of the jpayne@69: uncompressed data, or until it encounters an error. The function's jpayne@69: parameters and return types are defined above in the in_func and out_func jpayne@69: typedefs. inflateBack() will call in(in_desc, &buf) which should return the jpayne@69: number of bytes of provided input, and a pointer to that input in buf. If jpayne@69: there is no input available, in() must return zero -- buf is ignored in that jpayne@69: case -- and inflateBack() will return a buffer error. inflateBack() will jpayne@69: call out(out_desc, buf, len) to write the uncompressed data buf[0..len-1]. jpayne@69: out() should return zero on success, or non-zero on failure. If out() jpayne@69: returns non-zero, inflateBack() will return with an error. Neither in() nor jpayne@69: out() are permitted to change the contents of the window provided to jpayne@69: inflateBackInit(), which is also the buffer that out() uses to write from. jpayne@69: The length written by out() will be at most the window size. Any non-zero jpayne@69: amount of input may be provided by in(). jpayne@69: jpayne@69: For convenience, inflateBack() can be provided input on the first call by jpayne@69: setting strm->next_in and strm->avail_in. If that input is exhausted, then jpayne@69: in() will be called. Therefore strm->next_in must be initialized before jpayne@69: calling inflateBack(). If strm->next_in is Z_NULL, then in() will be called jpayne@69: immediately for input. If strm->next_in is not Z_NULL, then strm->avail_in jpayne@69: must also be initialized, and then if strm->avail_in is not zero, input will jpayne@69: initially be taken from strm->next_in[0 .. strm->avail_in - 1]. jpayne@69: jpayne@69: The in_desc and out_desc parameters of inflateBack() is passed as the jpayne@69: first parameter of in() and out() respectively when they are called. These jpayne@69: descriptors can be optionally used to pass any information that the caller- jpayne@69: supplied in() and out() functions need to do their job. jpayne@69: jpayne@69: On return, inflateBack() will set strm->next_in and strm->avail_in to jpayne@69: pass back any unused input that was provided by the last in() call. The jpayne@69: return values of inflateBack() can be Z_STREAM_END on success, Z_BUF_ERROR jpayne@69: if in() or out() returned an error, Z_DATA_ERROR if there was a format error jpayne@69: in the deflate stream (in which case strm->msg is set to indicate the nature jpayne@69: of the error), or Z_STREAM_ERROR if the stream was not properly initialized. jpayne@69: In the case of Z_BUF_ERROR, an input or output error can be distinguished jpayne@69: using strm->next_in which will be Z_NULL only if in() returned an error. If jpayne@69: strm->next_in is not Z_NULL, then the Z_BUF_ERROR was due to out() returning jpayne@69: non-zero. (in() will always be called before out(), so strm->next_in is jpayne@69: assured to be defined if out() returns non-zero.) Note that inflateBack() jpayne@69: cannot return Z_OK. jpayne@69: */ jpayne@69: jpayne@69: ZEXTERN int ZEXPORT inflateBackEnd OF((z_streamp strm)); jpayne@69: /* jpayne@69: All memory allocated by inflateBackInit() is freed. jpayne@69: jpayne@69: inflateBackEnd() returns Z_OK on success, or Z_STREAM_ERROR if the stream jpayne@69: state was inconsistent. jpayne@69: */ jpayne@69: jpayne@69: ZEXTERN uLong ZEXPORT zlibCompileFlags OF((void)); jpayne@69: /* Return flags indicating compile-time options. jpayne@69: jpayne@69: Type sizes, two bits each, 00 = 16 bits, 01 = 32, 10 = 64, 11 = other: jpayne@69: 1.0: size of uInt jpayne@69: 3.2: size of uLong jpayne@69: 5.4: size of voidpf (pointer) jpayne@69: 7.6: size of z_off_t jpayne@69: jpayne@69: Compiler, assembler, and debug options: jpayne@69: 8: ZLIB_DEBUG jpayne@69: 9: ASMV or ASMINF -- use ASM code jpayne@69: 10: ZLIB_WINAPI -- exported functions use the WINAPI calling convention jpayne@69: 11: 0 (reserved) jpayne@69: jpayne@69: One-time table building (smaller code, but not thread-safe if true): jpayne@69: 12: BUILDFIXED -- build static block decoding tables when needed jpayne@69: 13: DYNAMIC_CRC_TABLE -- build CRC calculation tables when needed jpayne@69: 14,15: 0 (reserved) jpayne@69: jpayne@69: Library content (indicates missing functionality): jpayne@69: 16: NO_GZCOMPRESS -- gz* functions cannot compress (to avoid linking jpayne@69: deflate code when not needed) jpayne@69: 17: NO_GZIP -- deflate can't write gzip streams, and inflate can't detect jpayne@69: and decode gzip streams (to avoid linking crc code) jpayne@69: 18-19: 0 (reserved) jpayne@69: jpayne@69: Operation variations (changes in library functionality): jpayne@69: 20: PKZIP_BUG_WORKAROUND -- slightly more permissive inflate jpayne@69: 21: FASTEST -- deflate algorithm with only one, lowest compression level jpayne@69: 22,23: 0 (reserved) jpayne@69: jpayne@69: The sprintf variant used by gzprintf (zero is best): jpayne@69: 24: 0 = vs*, 1 = s* -- 1 means limited to 20 arguments after the format jpayne@69: 25: 0 = *nprintf, 1 = *printf -- 1 means gzprintf() not secure! jpayne@69: 26: 0 = returns value, 1 = void -- 1 means inferred string length returned jpayne@69: jpayne@69: Remainder: jpayne@69: 27-31: 0 (reserved) jpayne@69: */ jpayne@69: jpayne@69: #ifndef Z_SOLO jpayne@69: jpayne@69: /* utility functions */ jpayne@69: jpayne@69: /* jpayne@69: The following utility functions are implemented on top of the basic jpayne@69: stream-oriented functions. To simplify the interface, some default options jpayne@69: are assumed (compression level and memory usage, standard memory allocation jpayne@69: functions). The source code of these utility functions can be modified if jpayne@69: you need special options. jpayne@69: */ jpayne@69: jpayne@69: ZEXTERN int ZEXPORT compress OF((Bytef *dest, uLongf *destLen, jpayne@69: const Bytef *source, uLong sourceLen)); jpayne@69: /* jpayne@69: Compresses the source buffer into the destination buffer. sourceLen is jpayne@69: the byte length of the source buffer. Upon entry, destLen is the total size jpayne@69: of the destination buffer, which must be at least the value returned by jpayne@69: compressBound(sourceLen). Upon exit, destLen is the actual size of the jpayne@69: compressed data. compress() is equivalent to compress2() with a level jpayne@69: parameter of Z_DEFAULT_COMPRESSION. jpayne@69: jpayne@69: compress returns Z_OK if success, Z_MEM_ERROR if there was not jpayne@69: enough memory, Z_BUF_ERROR if there was not enough room in the output jpayne@69: buffer. jpayne@69: */ jpayne@69: jpayne@69: ZEXTERN int ZEXPORT compress2 OF((Bytef *dest, uLongf *destLen, jpayne@69: const Bytef *source, uLong sourceLen, jpayne@69: int level)); jpayne@69: /* jpayne@69: Compresses the source buffer into the destination buffer. The level jpayne@69: parameter has the same meaning as in deflateInit. sourceLen is the byte jpayne@69: length of the source buffer. Upon entry, destLen is the total size of the jpayne@69: destination buffer, which must be at least the value returned by jpayne@69: compressBound(sourceLen). Upon exit, destLen is the actual size of the jpayne@69: compressed data. jpayne@69: jpayne@69: compress2 returns Z_OK if success, Z_MEM_ERROR if there was not enough jpayne@69: memory, Z_BUF_ERROR if there was not enough room in the output buffer, jpayne@69: Z_STREAM_ERROR if the level parameter is invalid. jpayne@69: */ jpayne@69: jpayne@69: ZEXTERN uLong ZEXPORT compressBound OF((uLong sourceLen)); jpayne@69: /* jpayne@69: compressBound() returns an upper bound on the compressed size after jpayne@69: compress() or compress2() on sourceLen bytes. It would be used before a jpayne@69: compress() or compress2() call to allocate the destination buffer. jpayne@69: */ jpayne@69: jpayne@69: ZEXTERN int ZEXPORT uncompress OF((Bytef *dest, uLongf *destLen, jpayne@69: const Bytef *source, uLong sourceLen)); jpayne@69: /* jpayne@69: Decompresses the source buffer into the destination buffer. sourceLen is jpayne@69: the byte length of the source buffer. Upon entry, destLen is the total size jpayne@69: of the destination buffer, which must be large enough to hold the entire jpayne@69: uncompressed data. (The size of the uncompressed data must have been saved jpayne@69: previously by the compressor and transmitted to the decompressor by some jpayne@69: mechanism outside the scope of this compression library.) Upon exit, destLen jpayne@69: is the actual size of the uncompressed data. jpayne@69: jpayne@69: uncompress returns Z_OK if success, Z_MEM_ERROR if there was not jpayne@69: enough memory, Z_BUF_ERROR if there was not enough room in the output jpayne@69: buffer, or Z_DATA_ERROR if the input data was corrupted or incomplete. In jpayne@69: the case where there is not enough room, uncompress() will fill the output jpayne@69: buffer with the uncompressed data up to that point. jpayne@69: */ jpayne@69: jpayne@69: ZEXTERN int ZEXPORT uncompress2 OF((Bytef *dest, uLongf *destLen, jpayne@69: const Bytef *source, uLong *sourceLen)); jpayne@69: /* jpayne@69: Same as uncompress, except that sourceLen is a pointer, where the jpayne@69: length of the source is *sourceLen. On return, *sourceLen is the number of jpayne@69: source bytes consumed. jpayne@69: */ jpayne@69: jpayne@69: /* gzip file access functions */ jpayne@69: jpayne@69: /* jpayne@69: This library supports reading and writing files in gzip (.gz) format with jpayne@69: an interface similar to that of stdio, using the functions that start with jpayne@69: "gz". The gzip format is different from the zlib format. gzip is a gzip jpayne@69: wrapper, documented in RFC 1952, wrapped around a deflate stream. jpayne@69: */ jpayne@69: jpayne@69: typedef struct gzFile_s *gzFile; /* semi-opaque gzip file descriptor */ jpayne@69: jpayne@69: /* jpayne@69: ZEXTERN gzFile ZEXPORT gzopen OF((const char *path, const char *mode)); jpayne@69: jpayne@69: Open the gzip (.gz) file at path for reading and decompressing, or jpayne@69: compressing and writing. The mode parameter is as in fopen ("rb" or "wb") jpayne@69: but can also include a compression level ("wb9") or a strategy: 'f' for jpayne@69: filtered data as in "wb6f", 'h' for Huffman-only compression as in "wb1h", jpayne@69: 'R' for run-length encoding as in "wb1R", or 'F' for fixed code compression jpayne@69: as in "wb9F". (See the description of deflateInit2 for more information jpayne@69: about the strategy parameter.) 'T' will request transparent writing or jpayne@69: appending with no compression and not using the gzip format. jpayne@69: jpayne@69: "a" can be used instead of "w" to request that the gzip stream that will jpayne@69: be written be appended to the file. "+" will result in an error, since jpayne@69: reading and writing to the same gzip file is not supported. The addition of jpayne@69: "x" when writing will create the file exclusively, which fails if the file jpayne@69: already exists. On systems that support it, the addition of "e" when jpayne@69: reading or writing will set the flag to close the file on an execve() call. jpayne@69: jpayne@69: These functions, as well as gzip, will read and decode a sequence of gzip jpayne@69: streams in a file. The append function of gzopen() can be used to create jpayne@69: such a file. (Also see gzflush() for another way to do this.) When jpayne@69: appending, gzopen does not test whether the file begins with a gzip stream, jpayne@69: nor does it look for the end of the gzip streams to begin appending. gzopen jpayne@69: will simply append a gzip stream to the existing file. jpayne@69: jpayne@69: gzopen can be used to read a file which is not in gzip format; in this jpayne@69: case gzread will directly read from the file without decompression. When jpayne@69: reading, this will be detected automatically by looking for the magic two- jpayne@69: byte gzip header. jpayne@69: jpayne@69: gzopen returns NULL if the file could not be opened, if there was jpayne@69: insufficient memory to allocate the gzFile state, or if an invalid mode was jpayne@69: specified (an 'r', 'w', or 'a' was not provided, or '+' was provided). jpayne@69: errno can be checked to determine if the reason gzopen failed was that the jpayne@69: file could not be opened. jpayne@69: */ jpayne@69: jpayne@69: ZEXTERN gzFile ZEXPORT gzdopen OF((int fd, const char *mode)); jpayne@69: /* jpayne@69: Associate a gzFile with the file descriptor fd. File descriptors are jpayne@69: obtained from calls like open, dup, creat, pipe or fileno (if the file has jpayne@69: been previously opened with fopen). The mode parameter is as in gzopen. jpayne@69: jpayne@69: The next call of gzclose on the returned gzFile will also close the file jpayne@69: descriptor fd, just like fclose(fdopen(fd, mode)) closes the file descriptor jpayne@69: fd. If you want to keep fd open, use fd = dup(fd_keep); gz = gzdopen(fd, jpayne@69: mode);. The duplicated descriptor should be saved to avoid a leak, since jpayne@69: gzdopen does not close fd if it fails. If you are using fileno() to get the jpayne@69: file descriptor from a FILE *, then you will have to use dup() to avoid jpayne@69: double-close()ing the file descriptor. Both gzclose() and fclose() will jpayne@69: close the associated file descriptor, so they need to have different file jpayne@69: descriptors. jpayne@69: jpayne@69: gzdopen returns NULL if there was insufficient memory to allocate the jpayne@69: gzFile state, if an invalid mode was specified (an 'r', 'w', or 'a' was not jpayne@69: provided, or '+' was provided), or if fd is -1. The file descriptor is not jpayne@69: used until the next gz* read, write, seek, or close operation, so gzdopen jpayne@69: will not detect if fd is invalid (unless fd is -1). jpayne@69: */ jpayne@69: jpayne@69: ZEXTERN int ZEXPORT gzbuffer OF((gzFile file, unsigned size)); jpayne@69: /* jpayne@69: Set the internal buffer size used by this library's functions for file to jpayne@69: size. The default buffer size is 8192 bytes. This function must be called jpayne@69: after gzopen() or gzdopen(), and before any other calls that read or write jpayne@69: the file. The buffer memory allocation is always deferred to the first read jpayne@69: or write. Three times that size in buffer space is allocated. A larger jpayne@69: buffer size of, for example, 64K or 128K bytes will noticeably increase the jpayne@69: speed of decompression (reading). jpayne@69: jpayne@69: The new buffer size also affects the maximum length for gzprintf(). jpayne@69: jpayne@69: gzbuffer() returns 0 on success, or -1 on failure, such as being called jpayne@69: too late. jpayne@69: */ jpayne@69: jpayne@69: ZEXTERN int ZEXPORT gzsetparams OF((gzFile file, int level, int strategy)); jpayne@69: /* jpayne@69: Dynamically update the compression level and strategy for file. See the jpayne@69: description of deflateInit2 for the meaning of these parameters. Previously jpayne@69: provided data is flushed before applying the parameter changes. jpayne@69: jpayne@69: gzsetparams returns Z_OK if success, Z_STREAM_ERROR if the file was not jpayne@69: opened for writing, Z_ERRNO if there is an error writing the flushed data, jpayne@69: or Z_MEM_ERROR if there is a memory allocation error. jpayne@69: */ jpayne@69: jpayne@69: ZEXTERN int ZEXPORT gzread OF((gzFile file, voidp buf, unsigned len)); jpayne@69: /* jpayne@69: Read and decompress up to len uncompressed bytes from file into buf. If jpayne@69: the input file is not in gzip format, gzread copies the given number of jpayne@69: bytes into the buffer directly from the file. jpayne@69: jpayne@69: After reaching the end of a gzip stream in the input, gzread will continue jpayne@69: to read, looking for another gzip stream. Any number of gzip streams may be jpayne@69: concatenated in the input file, and will all be decompressed by gzread(). jpayne@69: If something other than a gzip stream is encountered after a gzip stream, jpayne@69: that remaining trailing garbage is ignored (and no error is returned). jpayne@69: jpayne@69: gzread can be used to read a gzip file that is being concurrently written. jpayne@69: Upon reaching the end of the input, gzread will return with the available jpayne@69: data. If the error code returned by gzerror is Z_OK or Z_BUF_ERROR, then jpayne@69: gzclearerr can be used to clear the end of file indicator in order to permit jpayne@69: gzread to be tried again. Z_OK indicates that a gzip stream was completed jpayne@69: on the last gzread. Z_BUF_ERROR indicates that the input file ended in the jpayne@69: middle of a gzip stream. Note that gzread does not return -1 in the event jpayne@69: of an incomplete gzip stream. This error is deferred until gzclose(), which jpayne@69: will return Z_BUF_ERROR if the last gzread ended in the middle of a gzip jpayne@69: stream. Alternatively, gzerror can be used before gzclose to detect this jpayne@69: case. jpayne@69: jpayne@69: gzread returns the number of uncompressed bytes actually read, less than jpayne@69: len for end of file, or -1 for error. If len is too large to fit in an int, jpayne@69: then nothing is read, -1 is returned, and the error state is set to jpayne@69: Z_STREAM_ERROR. jpayne@69: */ jpayne@69: jpayne@69: ZEXTERN z_size_t ZEXPORT gzfread OF((voidp buf, z_size_t size, z_size_t nitems, jpayne@69: gzFile file)); jpayne@69: /* jpayne@69: Read and decompress up to nitems items of size size from file into buf, jpayne@69: otherwise operating as gzread() does. This duplicates the interface of jpayne@69: stdio's fread(), with size_t request and return types. If the library jpayne@69: defines size_t, then z_size_t is identical to size_t. If not, then z_size_t jpayne@69: is an unsigned integer type that can contain a pointer. jpayne@69: jpayne@69: gzfread() returns the number of full items read of size size, or zero if jpayne@69: the end of the file was reached and a full item could not be read, or if jpayne@69: there was an error. gzerror() must be consulted if zero is returned in jpayne@69: order to determine if there was an error. If the multiplication of size and jpayne@69: nitems overflows, i.e. the product does not fit in a z_size_t, then nothing jpayne@69: is read, zero is returned, and the error state is set to Z_STREAM_ERROR. jpayne@69: jpayne@69: In the event that the end of file is reached and only a partial item is jpayne@69: available at the end, i.e. the remaining uncompressed data length is not a jpayne@69: multiple of size, then the final partial item is nevertheless read into buf jpayne@69: and the end-of-file flag is set. The length of the partial item read is not jpayne@69: provided, but could be inferred from the result of gztell(). This behavior jpayne@69: is the same as the behavior of fread() implementations in common libraries, jpayne@69: but it prevents the direct use of gzfread() to read a concurrently written jpayne@69: file, resetting and retrying on end-of-file, when size is not 1. jpayne@69: */ jpayne@69: jpayne@69: ZEXTERN int ZEXPORT gzwrite OF((gzFile file, voidpc buf, unsigned len)); jpayne@69: /* jpayne@69: Compress and write the len uncompressed bytes at buf to file. gzwrite jpayne@69: returns the number of uncompressed bytes written or 0 in case of error. jpayne@69: */ jpayne@69: jpayne@69: ZEXTERN z_size_t ZEXPORT gzfwrite OF((voidpc buf, z_size_t size, jpayne@69: z_size_t nitems, gzFile file)); jpayne@69: /* jpayne@69: Compress and write nitems items of size size from buf to file, duplicating jpayne@69: the interface of stdio's fwrite(), with size_t request and return types. If jpayne@69: the library defines size_t, then z_size_t is identical to size_t. If not, jpayne@69: then z_size_t is an unsigned integer type that can contain a pointer. jpayne@69: jpayne@69: gzfwrite() returns the number of full items written of size size, or zero jpayne@69: if there was an error. If the multiplication of size and nitems overflows, jpayne@69: i.e. the product does not fit in a z_size_t, then nothing is written, zero jpayne@69: is returned, and the error state is set to Z_STREAM_ERROR. jpayne@69: */ jpayne@69: jpayne@69: ZEXTERN int ZEXPORTVA gzprintf Z_ARG((gzFile file, const char *format, ...)); jpayne@69: /* jpayne@69: Convert, format, compress, and write the arguments (...) to file under jpayne@69: control of the string format, as in fprintf. gzprintf returns the number of jpayne@69: uncompressed bytes actually written, or a negative zlib error code in case jpayne@69: of error. The number of uncompressed bytes written is limited to 8191, or jpayne@69: one less than the buffer size given to gzbuffer(). The caller should assure jpayne@69: that this limit is not exceeded. If it is exceeded, then gzprintf() will jpayne@69: return an error (0) with nothing written. In this case, there may also be a jpayne@69: buffer overflow with unpredictable consequences, which is possible only if jpayne@69: zlib was compiled with the insecure functions sprintf() or vsprintf(), jpayne@69: because the secure snprintf() or vsnprintf() functions were not available. jpayne@69: This can be determined using zlibCompileFlags(). jpayne@69: */ jpayne@69: jpayne@69: ZEXTERN int ZEXPORT gzputs OF((gzFile file, const char *s)); jpayne@69: /* jpayne@69: Compress and write the given null-terminated string s to file, excluding jpayne@69: the terminating null character. jpayne@69: jpayne@69: gzputs returns the number of characters written, or -1 in case of error. jpayne@69: */ jpayne@69: jpayne@69: ZEXTERN char * ZEXPORT gzgets OF((gzFile file, char *buf, int len)); jpayne@69: /* jpayne@69: Read and decompress bytes from file into buf, until len-1 characters are jpayne@69: read, or until a newline character is read and transferred to buf, or an jpayne@69: end-of-file condition is encountered. If any characters are read or if len jpayne@69: is one, the string is terminated with a null character. If no characters jpayne@69: are read due to an end-of-file or len is less than one, then the buffer is jpayne@69: left untouched. jpayne@69: jpayne@69: gzgets returns buf which is a null-terminated string, or it returns NULL jpayne@69: for end-of-file or in case of error. If there was an error, the contents at jpayne@69: buf are indeterminate. jpayne@69: */ jpayne@69: jpayne@69: ZEXTERN int ZEXPORT gzputc OF((gzFile file, int c)); jpayne@69: /* jpayne@69: Compress and write c, converted to an unsigned char, into file. gzputc jpayne@69: returns the value that was written, or -1 in case of error. jpayne@69: */ jpayne@69: jpayne@69: ZEXTERN int ZEXPORT gzgetc OF((gzFile file)); jpayne@69: /* jpayne@69: Read and decompress one byte from file. gzgetc returns this byte or -1 jpayne@69: in case of end of file or error. This is implemented as a macro for speed. jpayne@69: As such, it does not do all of the checking the other functions do. I.e. jpayne@69: it does not check to see if file is NULL, nor whether the structure file jpayne@69: points to has been clobbered or not. jpayne@69: */ jpayne@69: jpayne@69: ZEXTERN int ZEXPORT gzungetc OF((int c, gzFile file)); jpayne@69: /* jpayne@69: Push c back onto the stream for file to be read as the first character on jpayne@69: the next read. At least one character of push-back is always allowed. jpayne@69: gzungetc() returns the character pushed, or -1 on failure. gzungetc() will jpayne@69: fail if c is -1, and may fail if a character has been pushed but not read jpayne@69: yet. If gzungetc is used immediately after gzopen or gzdopen, at least the jpayne@69: output buffer size of pushed characters is allowed. (See gzbuffer above.) jpayne@69: The pushed character will be discarded if the stream is repositioned with jpayne@69: gzseek() or gzrewind(). jpayne@69: */ jpayne@69: jpayne@69: ZEXTERN int ZEXPORT gzflush OF((gzFile file, int flush)); jpayne@69: /* jpayne@69: Flush all pending output to file. The parameter flush is as in the jpayne@69: deflate() function. The return value is the zlib error number (see function jpayne@69: gzerror below). gzflush is only permitted when writing. jpayne@69: jpayne@69: If the flush parameter is Z_FINISH, the remaining data is written and the jpayne@69: gzip stream is completed in the output. If gzwrite() is called again, a new jpayne@69: gzip stream will be started in the output. gzread() is able to read such jpayne@69: concatenated gzip streams. jpayne@69: jpayne@69: gzflush should be called only when strictly necessary because it will jpayne@69: degrade compression if called too often. jpayne@69: */ jpayne@69: jpayne@69: /* jpayne@69: ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile file, jpayne@69: z_off_t offset, int whence)); jpayne@69: jpayne@69: Set the starting position to offset relative to whence for the next gzread jpayne@69: or gzwrite on file. The offset represents a number of bytes in the jpayne@69: uncompressed data stream. The whence parameter is defined as in lseek(2); jpayne@69: the value SEEK_END is not supported. jpayne@69: jpayne@69: If the file is opened for reading, this function is emulated but can be jpayne@69: extremely slow. If the file is opened for writing, only forward seeks are jpayne@69: supported; gzseek then compresses a sequence of zeroes up to the new jpayne@69: starting position. jpayne@69: jpayne@69: gzseek returns the resulting offset location as measured in bytes from jpayne@69: the beginning of the uncompressed stream, or -1 in case of error, in jpayne@69: particular if the file is opened for writing and the new starting position jpayne@69: would be before the current position. jpayne@69: */ jpayne@69: jpayne@69: ZEXTERN int ZEXPORT gzrewind OF((gzFile file)); jpayne@69: /* jpayne@69: Rewind file. This function is supported only for reading. jpayne@69: jpayne@69: gzrewind(file) is equivalent to (int)gzseek(file, 0L, SEEK_SET). jpayne@69: */ jpayne@69: jpayne@69: /* jpayne@69: ZEXTERN z_off_t ZEXPORT gztell OF((gzFile file)); jpayne@69: jpayne@69: Return the starting position for the next gzread or gzwrite on file. jpayne@69: This position represents a number of bytes in the uncompressed data stream, jpayne@69: and is zero when starting, even if appending or reading a gzip stream from jpayne@69: the middle of a file using gzdopen(). jpayne@69: jpayne@69: gztell(file) is equivalent to gzseek(file, 0L, SEEK_CUR) jpayne@69: */ jpayne@69: jpayne@69: /* jpayne@69: ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile file)); jpayne@69: jpayne@69: Return the current compressed (actual) read or write offset of file. This jpayne@69: offset includes the count of bytes that precede the gzip stream, for example jpayne@69: when appending or when using gzdopen() for reading. When reading, the jpayne@69: offset does not include as yet unused buffered input. This information can jpayne@69: be used for a progress indicator. On error, gzoffset() returns -1. jpayne@69: */ jpayne@69: jpayne@69: ZEXTERN int ZEXPORT gzeof OF((gzFile file)); jpayne@69: /* jpayne@69: Return true (1) if the end-of-file indicator for file has been set while jpayne@69: reading, false (0) otherwise. Note that the end-of-file indicator is set jpayne@69: only if the read tried to go past the end of the input, but came up short. jpayne@69: Therefore, just like feof(), gzeof() may return false even if there is no jpayne@69: more data to read, in the event that the last read request was for the exact jpayne@69: number of bytes remaining in the input file. This will happen if the input jpayne@69: file size is an exact multiple of the buffer size. jpayne@69: jpayne@69: If gzeof() returns true, then the read functions will return no more data, jpayne@69: unless the end-of-file indicator is reset by gzclearerr() and the input file jpayne@69: has grown since the previous end of file was detected. jpayne@69: */ jpayne@69: jpayne@69: ZEXTERN int ZEXPORT gzdirect OF((gzFile file)); jpayne@69: /* jpayne@69: Return true (1) if file is being copied directly while reading, or false jpayne@69: (0) if file is a gzip stream being decompressed. jpayne@69: jpayne@69: If the input file is empty, gzdirect() will return true, since the input jpayne@69: does not contain a gzip stream. jpayne@69: jpayne@69: If gzdirect() is used immediately after gzopen() or gzdopen() it will jpayne@69: cause buffers to be allocated to allow reading the file to determine if it jpayne@69: is a gzip file. Therefore if gzbuffer() is used, it should be called before jpayne@69: gzdirect(). jpayne@69: jpayne@69: When writing, gzdirect() returns true (1) if transparent writing was jpayne@69: requested ("wT" for the gzopen() mode), or false (0) otherwise. (Note: jpayne@69: gzdirect() is not needed when writing. Transparent writing must be jpayne@69: explicitly requested, so the application already knows the answer. When jpayne@69: linking statically, using gzdirect() will include all of the zlib code for jpayne@69: gzip file reading and decompression, which may not be desired.) jpayne@69: */ jpayne@69: jpayne@69: ZEXTERN int ZEXPORT gzclose OF((gzFile file)); jpayne@69: /* jpayne@69: Flush all pending output for file, if necessary, close file and jpayne@69: deallocate the (de)compression state. Note that once file is closed, you jpayne@69: cannot call gzerror with file, since its structures have been deallocated. jpayne@69: gzclose must not be called more than once on the same file, just as free jpayne@69: must not be called more than once on the same allocation. jpayne@69: jpayne@69: gzclose will return Z_STREAM_ERROR if file is not valid, Z_ERRNO on a jpayne@69: file operation error, Z_MEM_ERROR if out of memory, Z_BUF_ERROR if the jpayne@69: last read ended in the middle of a gzip stream, or Z_OK on success. jpayne@69: */ jpayne@69: jpayne@69: ZEXTERN int ZEXPORT gzclose_r OF((gzFile file)); jpayne@69: ZEXTERN int ZEXPORT gzclose_w OF((gzFile file)); jpayne@69: /* jpayne@69: Same as gzclose(), but gzclose_r() is only for use when reading, and jpayne@69: gzclose_w() is only for use when writing or appending. The advantage to jpayne@69: using these instead of gzclose() is that they avoid linking in zlib jpayne@69: compression or decompression code that is not used when only reading or only jpayne@69: writing respectively. If gzclose() is used, then both compression and jpayne@69: decompression code will be included the application when linking to a static jpayne@69: zlib library. jpayne@69: */ jpayne@69: jpayne@69: ZEXTERN const char * ZEXPORT gzerror OF((gzFile file, int *errnum)); jpayne@69: /* jpayne@69: Return the error message for the last error which occurred on file. jpayne@69: errnum is set to zlib error number. If an error occurred in the file system jpayne@69: and not in the compression library, errnum is set to Z_ERRNO and the jpayne@69: application may consult errno to get the exact error code. jpayne@69: jpayne@69: The application must not modify the returned string. Future calls to jpayne@69: this function may invalidate the previously returned string. If file is jpayne@69: closed, then the string previously returned by gzerror will no longer be jpayne@69: available. jpayne@69: jpayne@69: gzerror() should be used to distinguish errors from end-of-file for those jpayne@69: functions above that do not distinguish those cases in their return values. jpayne@69: */ jpayne@69: jpayne@69: ZEXTERN void ZEXPORT gzclearerr OF((gzFile file)); jpayne@69: /* jpayne@69: Clear the error and end-of-file flags for file. This is analogous to the jpayne@69: clearerr() function in stdio. This is useful for continuing to read a gzip jpayne@69: file that is being written concurrently. jpayne@69: */ jpayne@69: jpayne@69: #endif /* !Z_SOLO */ jpayne@69: jpayne@69: /* checksum functions */ jpayne@69: jpayne@69: /* jpayne@69: These functions are not related to compression but are exported jpayne@69: anyway because they might be useful in applications using the compression jpayne@69: library. jpayne@69: */ jpayne@69: jpayne@69: ZEXTERN uLong ZEXPORT adler32 OF((uLong adler, const Bytef *buf, uInt len)); jpayne@69: /* jpayne@69: Update a running Adler-32 checksum with the bytes buf[0..len-1] and jpayne@69: return the updated checksum. An Adler-32 value is in the range of a 32-bit jpayne@69: unsigned integer. If buf is Z_NULL, this function returns the required jpayne@69: initial value for the checksum. jpayne@69: jpayne@69: An Adler-32 checksum is almost as reliable as a CRC-32 but can be computed jpayne@69: much faster. jpayne@69: jpayne@69: Usage example: jpayne@69: jpayne@69: uLong adler = adler32(0L, Z_NULL, 0); jpayne@69: jpayne@69: while (read_buffer(buffer, length) != EOF) { jpayne@69: adler = adler32(adler, buffer, length); jpayne@69: } jpayne@69: if (adler != original_adler) error(); jpayne@69: */ jpayne@69: jpayne@69: ZEXTERN uLong ZEXPORT adler32_z OF((uLong adler, const Bytef *buf, jpayne@69: z_size_t len)); jpayne@69: /* jpayne@69: Same as adler32(), but with a size_t length. jpayne@69: */ jpayne@69: jpayne@69: /* jpayne@69: ZEXTERN uLong ZEXPORT adler32_combine OF((uLong adler1, uLong adler2, jpayne@69: z_off_t len2)); jpayne@69: jpayne@69: Combine two Adler-32 checksums into one. For two sequences of bytes, seq1 jpayne@69: and seq2 with lengths len1 and len2, Adler-32 checksums were calculated for jpayne@69: each, adler1 and adler2. adler32_combine() returns the Adler-32 checksum of jpayne@69: seq1 and seq2 concatenated, requiring only adler1, adler2, and len2. Note jpayne@69: that the z_off_t type (like off_t) is a signed integer. If len2 is jpayne@69: negative, the result has no meaning or utility. jpayne@69: */ jpayne@69: jpayne@69: ZEXTERN uLong ZEXPORT crc32 OF((uLong crc, const Bytef *buf, uInt len)); jpayne@69: /* jpayne@69: Update a running CRC-32 with the bytes buf[0..len-1] and return the jpayne@69: updated CRC-32. A CRC-32 value is in the range of a 32-bit unsigned integer. jpayne@69: If buf is Z_NULL, this function returns the required initial value for the jpayne@69: crc. Pre- and post-conditioning (one's complement) is performed within this jpayne@69: function so it shouldn't be done by the application. jpayne@69: jpayne@69: Usage example: jpayne@69: jpayne@69: uLong crc = crc32(0L, Z_NULL, 0); jpayne@69: jpayne@69: while (read_buffer(buffer, length) != EOF) { jpayne@69: crc = crc32(crc, buffer, length); jpayne@69: } jpayne@69: if (crc != original_crc) error(); jpayne@69: */ jpayne@69: jpayne@69: ZEXTERN uLong ZEXPORT crc32_z OF((uLong crc, const Bytef *buf, jpayne@69: z_size_t len)); jpayne@69: /* jpayne@69: Same as crc32(), but with a size_t length. jpayne@69: */ jpayne@69: jpayne@69: /* jpayne@69: ZEXTERN uLong ZEXPORT crc32_combine OF((uLong crc1, uLong crc2, z_off_t len2)); jpayne@69: jpayne@69: Combine two CRC-32 check values into one. For two sequences of bytes, jpayne@69: seq1 and seq2 with lengths len1 and len2, CRC-32 check values were jpayne@69: calculated for each, crc1 and crc2. crc32_combine() returns the CRC-32 jpayne@69: check value of seq1 and seq2 concatenated, requiring only crc1, crc2, and jpayne@69: len2. jpayne@69: */ jpayne@69: jpayne@69: /* jpayne@69: ZEXTERN uLong ZEXPORT crc32_combine_gen OF((z_off_t len2)); jpayne@69: jpayne@69: Return the operator corresponding to length len2, to be used with jpayne@69: crc32_combine_op(). jpayne@69: */ jpayne@69: jpayne@69: ZEXTERN uLong ZEXPORT crc32_combine_op OF((uLong crc1, uLong crc2, uLong op)); jpayne@69: /* jpayne@69: Give the same result as crc32_combine(), using op in place of len2. op is jpayne@69: is generated from len2 by crc32_combine_gen(). This will be faster than jpayne@69: crc32_combine() if the generated op is used more than once. jpayne@69: */ jpayne@69: jpayne@69: jpayne@69: /* various hacks, don't look :) */ jpayne@69: jpayne@69: /* deflateInit and inflateInit are macros to allow checking the zlib version jpayne@69: * and the compiler's view of z_stream: jpayne@69: */ jpayne@69: ZEXTERN int ZEXPORT deflateInit_ OF((z_streamp strm, int level, jpayne@69: const char *version, int stream_size)); jpayne@69: ZEXTERN int ZEXPORT inflateInit_ OF((z_streamp strm, jpayne@69: const char *version, int stream_size)); jpayne@69: ZEXTERN int ZEXPORT deflateInit2_ OF((z_streamp strm, int level, int method, jpayne@69: int windowBits, int memLevel, jpayne@69: int strategy, const char *version, jpayne@69: int stream_size)); jpayne@69: ZEXTERN int ZEXPORT inflateInit2_ OF((z_streamp strm, int windowBits, jpayne@69: const char *version, int stream_size)); jpayne@69: ZEXTERN int ZEXPORT inflateBackInit_ OF((z_streamp strm, int windowBits, jpayne@69: unsigned char FAR *window, jpayne@69: const char *version, jpayne@69: int stream_size)); jpayne@69: #ifdef Z_PREFIX_SET jpayne@69: # define z_deflateInit(strm, level) \ jpayne@69: deflateInit_((strm), (level), ZLIB_VERSION, (int)sizeof(z_stream)) jpayne@69: # define z_inflateInit(strm) \ jpayne@69: inflateInit_((strm), ZLIB_VERSION, (int)sizeof(z_stream)) jpayne@69: # define z_deflateInit2(strm, level, method, windowBits, memLevel, strategy) \ jpayne@69: deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\ jpayne@69: (strategy), ZLIB_VERSION, (int)sizeof(z_stream)) jpayne@69: # define z_inflateInit2(strm, windowBits) \ jpayne@69: inflateInit2_((strm), (windowBits), ZLIB_VERSION, \ jpayne@69: (int)sizeof(z_stream)) jpayne@69: # define z_inflateBackInit(strm, windowBits, window) \ jpayne@69: inflateBackInit_((strm), (windowBits), (window), \ jpayne@69: ZLIB_VERSION, (int)sizeof(z_stream)) jpayne@69: #else jpayne@69: # define deflateInit(strm, level) \ jpayne@69: deflateInit_((strm), (level), ZLIB_VERSION, (int)sizeof(z_stream)) jpayne@69: # define inflateInit(strm) \ jpayne@69: inflateInit_((strm), ZLIB_VERSION, (int)sizeof(z_stream)) jpayne@69: # define deflateInit2(strm, level, method, windowBits, memLevel, strategy) \ jpayne@69: deflateInit2_((strm),(level),(method),(windowBits),(memLevel),\ jpayne@69: (strategy), ZLIB_VERSION, (int)sizeof(z_stream)) jpayne@69: # define inflateInit2(strm, windowBits) \ jpayne@69: inflateInit2_((strm), (windowBits), ZLIB_VERSION, \ jpayne@69: (int)sizeof(z_stream)) jpayne@69: # define inflateBackInit(strm, windowBits, window) \ jpayne@69: inflateBackInit_((strm), (windowBits), (window), \ jpayne@69: ZLIB_VERSION, (int)sizeof(z_stream)) jpayne@69: #endif jpayne@69: jpayne@69: #ifndef Z_SOLO jpayne@69: jpayne@69: /* gzgetc() macro and its supporting function and exposed data structure. Note jpayne@69: * that the real internal state is much larger than the exposed structure. jpayne@69: * This abbreviated structure exposes just enough for the gzgetc() macro. The jpayne@69: * user should not mess with these exposed elements, since their names or jpayne@69: * behavior could change in the future, perhaps even capriciously. They can jpayne@69: * only be used by the gzgetc() macro. You have been warned. jpayne@69: */ jpayne@69: struct gzFile_s { jpayne@69: unsigned have; jpayne@69: unsigned char *next; jpayne@69: z_off64_t pos; jpayne@69: }; jpayne@69: ZEXTERN int ZEXPORT gzgetc_ OF((gzFile file)); /* backward compatibility */ jpayne@69: #ifdef Z_PREFIX_SET jpayne@69: # undef z_gzgetc jpayne@69: # define z_gzgetc(g) \ jpayne@69: ((g)->have ? ((g)->have--, (g)->pos++, *((g)->next)++) : (gzgetc)(g)) jpayne@69: #else jpayne@69: # define gzgetc(g) \ jpayne@69: ((g)->have ? ((g)->have--, (g)->pos++, *((g)->next)++) : (gzgetc)(g)) jpayne@69: #endif jpayne@69: jpayne@69: /* provide 64-bit offset functions if _LARGEFILE64_SOURCE defined, and/or jpayne@69: * change the regular functions to 64 bits if _FILE_OFFSET_BITS is 64 (if jpayne@69: * both are true, the application gets the *64 functions, and the regular jpayne@69: * functions are changed to 64 bits) -- in case these are set on systems jpayne@69: * without large file support, _LFS64_LARGEFILE must also be true jpayne@69: */ jpayne@69: #ifdef Z_LARGE64 jpayne@69: ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *)); jpayne@69: ZEXTERN z_off64_t ZEXPORT gzseek64 OF((gzFile, z_off64_t, int)); jpayne@69: ZEXTERN z_off64_t ZEXPORT gztell64 OF((gzFile)); jpayne@69: ZEXTERN z_off64_t ZEXPORT gzoffset64 OF((gzFile)); jpayne@69: ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off64_t)); jpayne@69: ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off64_t)); jpayne@69: ZEXTERN uLong ZEXPORT crc32_combine_gen64 OF((z_off64_t)); jpayne@69: #endif jpayne@69: jpayne@69: #if !defined(ZLIB_INTERNAL) && defined(Z_WANT64) jpayne@69: # ifdef Z_PREFIX_SET jpayne@69: # define z_gzopen z_gzopen64 jpayne@69: # define z_gzseek z_gzseek64 jpayne@69: # define z_gztell z_gztell64 jpayne@69: # define z_gzoffset z_gzoffset64 jpayne@69: # define z_adler32_combine z_adler32_combine64 jpayne@69: # define z_crc32_combine z_crc32_combine64 jpayne@69: # define z_crc32_combine_gen z_crc32_combine_gen64 jpayne@69: # else jpayne@69: # define gzopen gzopen64 jpayne@69: # define gzseek gzseek64 jpayne@69: # define gztell gztell64 jpayne@69: # define gzoffset gzoffset64 jpayne@69: # define adler32_combine adler32_combine64 jpayne@69: # define crc32_combine crc32_combine64 jpayne@69: # define crc32_combine_gen crc32_combine_gen64 jpayne@69: # endif jpayne@69: # ifndef Z_LARGE64 jpayne@69: ZEXTERN gzFile ZEXPORT gzopen64 OF((const char *, const char *)); jpayne@69: ZEXTERN z_off_t ZEXPORT gzseek64 OF((gzFile, z_off_t, int)); jpayne@69: ZEXTERN z_off_t ZEXPORT gztell64 OF((gzFile)); jpayne@69: ZEXTERN z_off_t ZEXPORT gzoffset64 OF((gzFile)); jpayne@69: ZEXTERN uLong ZEXPORT adler32_combine64 OF((uLong, uLong, z_off_t)); jpayne@69: ZEXTERN uLong ZEXPORT crc32_combine64 OF((uLong, uLong, z_off_t)); jpayne@69: ZEXTERN uLong ZEXPORT crc32_combine_gen64 OF((z_off_t)); jpayne@69: # endif jpayne@69: #else jpayne@69: ZEXTERN gzFile ZEXPORT gzopen OF((const char *, const char *)); jpayne@69: ZEXTERN z_off_t ZEXPORT gzseek OF((gzFile, z_off_t, int)); jpayne@69: ZEXTERN z_off_t ZEXPORT gztell OF((gzFile)); jpayne@69: ZEXTERN z_off_t ZEXPORT gzoffset OF((gzFile)); jpayne@69: ZEXTERN uLong ZEXPORT adler32_combine OF((uLong, uLong, z_off_t)); jpayne@69: ZEXTERN uLong ZEXPORT crc32_combine OF((uLong, uLong, z_off_t)); jpayne@69: ZEXTERN uLong ZEXPORT crc32_combine_gen OF((z_off_t)); jpayne@69: #endif jpayne@69: jpayne@69: #else /* Z_SOLO */ jpayne@69: jpayne@69: ZEXTERN uLong ZEXPORT adler32_combine OF((uLong, uLong, z_off_t)); jpayne@69: ZEXTERN uLong ZEXPORT crc32_combine OF((uLong, uLong, z_off_t)); jpayne@69: ZEXTERN uLong ZEXPORT crc32_combine_gen OF((z_off_t)); jpayne@69: jpayne@69: #endif /* !Z_SOLO */ jpayne@69: jpayne@69: /* undocumented functions */ jpayne@69: ZEXTERN const char * ZEXPORT zError OF((int)); jpayne@69: ZEXTERN int ZEXPORT inflateSyncPoint OF((z_streamp)); jpayne@69: ZEXTERN const z_crc_t FAR * ZEXPORT get_crc_table OF((void)); jpayne@69: ZEXTERN int ZEXPORT inflateUndermine OF((z_streamp, int)); jpayne@69: ZEXTERN int ZEXPORT inflateValidate OF((z_streamp, int)); jpayne@69: ZEXTERN unsigned long ZEXPORT inflateCodesUsed OF((z_streamp)); jpayne@69: ZEXTERN int ZEXPORT inflateResetKeep OF((z_streamp)); jpayne@69: ZEXTERN int ZEXPORT deflateResetKeep OF((z_streamp)); jpayne@69: #if defined(_WIN32) && !defined(Z_SOLO) jpayne@69: ZEXTERN gzFile ZEXPORT gzopen_w OF((const wchar_t *path, jpayne@69: const char *mode)); jpayne@69: #endif jpayne@69: #if defined(STDC) || defined(Z_HAVE_STDARG_H) jpayne@69: # ifndef Z_SOLO jpayne@69: ZEXTERN int ZEXPORTVA gzvprintf Z_ARG((gzFile file, jpayne@69: const char *format, jpayne@69: va_list va)); jpayne@69: # endif jpayne@69: #endif jpayne@69: jpayne@69: #ifdef __cplusplus jpayne@69: } jpayne@69: #endif jpayne@69: jpayne@69: #endif /* ZLIB_H */