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Diffstat (limited to 'src/include/timegm.h')
-rw-r--r-- | src/include/timegm.h | 79 |
1 files changed, 79 insertions, 0 deletions
diff --git a/src/include/timegm.h b/src/include/timegm.h new file mode 100644 index 00000000..fb970432 --- /dev/null +++ b/src/include/timegm.h @@ -0,0 +1,79 @@ +// (C) Copyright Howard Hinnant +// (C) Copyright 2010-2011 Vicente J. Botet Escriba +// Use, modification and distribution are subject to the Boost Software License, +// Version 1.0. (See accompanying file LICENSE_1_0.txt or copy at +// http://www.boost.org/LICENSE_1_0.txt). + +//===-------------------------- locale ------------------------------------===// +// +// The LLVM Compiler Infrastructure +// +// This file is dual licensed under the MIT and the University of Illinois Open +// Source Licenses. See LICENSE.TXT for details. +// +//===----------------------------------------------------------------------===// + +// This code was adapted by Vicente from Howard Hinnant's experimental work +// on chrono i/o to Boost and some functions from libc++/locale to emulate the missing time_get::get() + +#ifndef BOOST_CHRONO_IO_TIME_POINT_IO_H +#define BOOST_CHRONO_IO_TIME_POINT_IO_H + +#include <time.h> + +static int32_t is_leap(int32_t year) { + if(year % 400 == 0) + return 1; + if(year % 100 == 0) + return 0; + if(year % 4 == 0) + return 1; + return 0; +} + +static int32_t days_from_0(int32_t year) { + year--; + return 365 * year + (year / 400) - (year/100) + (year / 4); +} + +int32_t static days_from_1970(int32_t year) { + static const int days_from_0_to_1970 = days_from_0(1970); + return days_from_0(year) - days_from_0_to_1970; +} + +static int32_t days_from_1jan(int32_t year,int32_t month,int32_t day) { + static const int32_t days[2][12] = + { + { 0,31,59,90,120,151,181,212,243,273,304,334}, + { 0,31,60,91,121,152,182,213,244,274,305,335} + }; + + return days[is_leap(year)][month-1] + day - 1; +} + +static time_t internal_timegm(tm const *t) { + int year = t->tm_year + 1900; + int month = t->tm_mon; + if(month > 11) + { + year += month/12; + month %= 12; + } + else if(month < 0) + { + int years_diff = (-month + 11)/12; + year -= years_diff; + month+=12 * years_diff; + } + month++; + int day = t->tm_mday; + int day_of_year = days_from_1jan(year,month,day); + int days_since_epoch = days_from_1970(year) + day_of_year ; + + time_t seconds_in_day = 3600 * 24; + time_t result = seconds_in_day * days_since_epoch + 3600 * t->tm_hour + 60 * t->tm_min + t->tm_sec; + + return result; +} + +#endif |