lib: rename include dir to babeltrace2
[babeltrace.git] / include / babeltrace2 / compat / utc-internal.h
1 #ifndef _BABELTRACE_UTC_H
2 #define _BABELTRACE_UTC_H
3
4 /*
5 * Copyright (C) 2011-2013 Mathieu Desnoyers <mathieu.desnoyers@efficios.com>
6 *
7 * Permission is hereby granted, free of charge, to any person obtaining a copy
8 * of this software and associated documentation files (the "Software"), to deal
9 * in the Software without restriction, including without limitation the rights
10 * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
11 * copies of the Software, and to permit persons to whom the Software is
12 * furnished to do so, subject to the following conditions:
13 *
14 * The above copyright notice and this permission notice shall be included in
15 * all copies or substantial portions of the Software.
16 *
17 * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
18 * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
19 * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
20 * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
21 * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
22 * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN THE
23 * SOFTWARE.
24 */
25
26 #include <time.h>
27
28 /* If set, use GNU or BSD timegm(3) */
29 #if defined(_BSD_SOURCE) || defined(_SVID_SOURCE)
30
31 static inline
32 time_t bt_timegm(struct tm *tm)
33 {
34 return timegm(tm);
35 }
36
37 #elif defined(__MINGW32__)
38
39 static inline
40 time_t bt_timegm(struct tm *tm)
41 {
42 return _mkgmtime(tm);
43 }
44
45 #else
46
47 #include <errno.h>
48
49 /*
50 * This is a simple implementation of timegm() it just turns the "struct tm" into
51 * a GMT time_t. It does not normalize any of the fields of the "struct tm", nor
52 * does it set tm_wday or tm_yday.
53 */
54
55 static inline
56 int bt_leapyear(int year)
57 {
58 return ((year % 4) == 0 && ((year % 100) != 0 || (year % 400) == 0));
59 }
60
61 static inline
62 time_t bt_timegm(struct tm *tm)
63 {
64 int year, month, total_days;
65
66 int monthlen[2][12] = {
67 /* Days per month for a regular year */
68 { 31, 28, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 },
69 /* Days per month for a leap year */
70 { 31, 29, 31, 30, 31, 30, 31, 31, 30, 31, 30, 31 },
71 };
72
73 if ((tm->tm_mon >= 12) ||
74 (tm->tm_mday >= 32) ||
75 (tm->tm_hour >= 24) ||
76 (tm->tm_min >= 60) ||
77 (tm->tm_sec >= 61)) {
78 errno = EOVERFLOW;
79 return (time_t) -1;
80 }
81
82 /* Add 365 days for each year since 1970 */
83 total_days = 365 * (tm->tm_year - 70);
84
85 /* Add one day for each leap year since 1970 */
86 for (year = 70; year < tm->tm_year; year++) {
87 if (bt_leapyear(1900 + year)) {
88 total_days++;
89 }
90 }
91
92 /* Add days for each remaining month */
93 for (month = 0; month < tm->tm_mon; month++) {
94 total_days += monthlen[bt_leapyear(1900 + year)][month];
95 }
96
97 /* Add remaining days */
98 total_days += tm->tm_mday - 1;
99
100 return ((((total_days * 24) + tm->tm_hour) * 60 + tm->tm_min) * 60 + tm->tm_sec);
101 }
102
103 #endif
104
105 #endif /* _BABELTRACE_UTC_H */
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