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planemo upload commit 2e9511a184a1ca667c7be0c6321a36dc4e3d116d
author jpayne
date Tue, 18 Mar 2025 17:55:14 -0400
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1 // Copyright (c) 2014 Google Inc. (contributed by Remy Blank <rblank@google.com>)
2 // Copyright (c) 2013-2014 Sandstorm Development Group, Inc. and contributors
3 // Licensed under the MIT License:
4 //
5 // Permission is hereby granted, free of charge, to any person obtaining a copy
6 // of this software and associated documentation files (the "Software"), to deal
7 // in the Software without restriction, including without limitation the rights
8 // to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
9 // copies of the Software, and to permit persons to whom the Software is
10 // furnished to do so, subject to the following conditions:
11 //
12 // The above copyright notice and this permission notice shall be included in
13 // all copies or substantial portions of the Software.
14 //
15 // THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
16 // IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
17 // FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
18 // AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
19 // LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
20 // OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
21 // THE SOFTWARE.
22
23 #pragma once
24
25 #include "units.h"
26 #include <inttypes.h>
27 #include "string.h"
28
29 KJ_BEGIN_HEADER
30
31 namespace kj {
32 namespace _ { // private
33
34 class NanosecondLabel;
35 class TimeLabel;
36 class DateLabel;
37
38 static constexpr size_t TIME_STR_LEN = sizeof(int64_t) * 3 + 8;
39 // Maximum length of a stringified time. 3 digits per byte of integer, plus 8 digits to cover
40 // negative sign, decimal point, unit, NUL terminator, and anything else that might sneak in.
41
42 } // namespace _ (private)
43
44 using Duration = Quantity<int64_t, _::NanosecondLabel>;
45 // A time value, in nanoseconds.
46
47 constexpr Duration NANOSECONDS = unit<Duration>();
48 constexpr Duration MICROSECONDS = 1000 * NANOSECONDS;
49 constexpr Duration MILLISECONDS = 1000 * MICROSECONDS;
50 constexpr Duration SECONDS = 1000 * MILLISECONDS;
51 constexpr Duration MINUTES = 60 * SECONDS;
52 constexpr Duration HOURS = 60 * MINUTES;
53 constexpr Duration DAYS = 24 * HOURS;
54
55 using TimePoint = Absolute<Duration, _::TimeLabel>;
56 // An absolute time measured by some particular instance of `Timer` or `MonotonicClock`. `Time`s
57 // from two different `Timer`s or `MonotonicClock`s may be measured from different origins and so
58 // are not necessarily compatible.
59
60 using Date = Absolute<Duration, _::DateLabel>;
61 // A point in real-world time, measured relative to the Unix epoch (Jan 1, 1970 00:00:00 UTC).
62
63 CappedArray<char, _::TIME_STR_LEN> KJ_STRINGIFY(TimePoint);
64 CappedArray<char, _::TIME_STR_LEN> KJ_STRINGIFY(Date);
65 CappedArray<char, _::TIME_STR_LEN> KJ_STRINGIFY(Duration);
66
67 constexpr Date UNIX_EPOCH = origin<Date>();
68 // The `Date` representing Jan 1, 1970 00:00:00 UTC.
69
70 class Clock {
71 // Interface to read the current date and time.
72 public:
73 virtual Date now() const = 0;
74 };
75
76 class MonotonicClock {
77 // Interface to read time in a way that increases as real-world time increases, independent of
78 // any manual changes to the calendar date/time. Such a clock never "goes backwards" even if the
79 // system administrator changes the calendar time or suspends the system. However, this clock's
80 // time points are only meaningful in comparison to other time points from the same clock, and
81 // cannot be used to determine the current calendar date.
82
83 public:
84 virtual TimePoint now() const = 0;
85 };
86
87 const Clock& nullClock();
88 // A clock which always returns UNIX_EPOCH as the current time. Useful when you don't care about
89 // time.
90
91 const Clock& systemCoarseCalendarClock();
92 const Clock& systemPreciseCalendarClock();
93 // A clock that reads the real system time.
94 //
95 // In well-designed code, this should only be called by the top-level dependency injector. All
96 // other modules should request that the caller provide a Clock so that alternate clock
97 // implementations can be injected for testing, simulation, reproducibility, and other purposes.
98 //
99 // The "coarse" version has precision around 1-10ms, while the "precise" version has precision
100 // better than 1us. The "precise" version may be slightly slower, though on modern hardware and
101 // a reasonable operating system the difference is usually negligible.
102 //
103 // Note: On Windows prior to Windows 8, there is no precise calendar clock; the "precise" clock
104 // will be no more precise than the "coarse" clock in this case.
105
106 const MonotonicClock& systemCoarseMonotonicClock();
107 const MonotonicClock& systemPreciseMonotonicClock();
108 // A MonotonicClock that reads the real system time.
109 //
110 // In well-designed code, this should only be called by the top-level dependency injector. All
111 // other modules should request that the caller provide a Clock so that alternate clock
112 // implementations can be injected for testing, simulation, reproducibility, and other purposes.
113 //
114 // The "coarse" version has precision around 1-10ms, while the "precise" version has precision
115 // better than 1us. The "precise" version may be slightly slower, though on modern hardware and
116 // a reasonable operating system the difference is usually negligible.
117 } // namespace kj
118
119 KJ_END_HEADER