| 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 */ |