mirror of https://code.videolan.org/videolan/vlc
73 lines
2.2 KiB
C
73 lines
2.2 KiB
C
/*****************************************************************************
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* timegm.c: BSD/GNU timegm() replacement
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*****************************************************************************
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* Copyright © 2007 Laurent Aimar
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* Copyright © 2015 Rémi Denis-Courmont
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*
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* This program is free software; you can redistribute it and/or modify it
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* under the terms of the GNU Lesser General Public License as published by
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* the Free Software Foundation; either version 2.1 of the License, or
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* (at your option) any later version.
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*
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* This program is distributed in the hope that it will be useful,
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* but WITHOUT ANY WARRANTY; without even the implied warranty of
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* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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* GNU Lesser General Public License for more details.
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*
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* You should have received a copy of the GNU Lesser General Public License
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* along with this program; if not, write to the Free Software Foundation,
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* Inc., 51 Franklin Street, Fifth Floor, Boston MA 02110-1301, USA.
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*****************************************************************************/
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#ifdef HAVE_CONFIG_H
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# include <config.h>
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#endif
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#include <stdbool.h>
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#include <time.h>
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static bool is_leap_year(unsigned y)
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{
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if (y % 4)
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return false;
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if (y % 100)
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return true;
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if (y % 400)
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return false;
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return true;
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}
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time_t timegm(struct tm *tm)
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{
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static const unsigned ydays[12 + 1] = {
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0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334
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};
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if (tm->tm_year < 70 /* FIXME: (negative) dates before Epoch */
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|| tm->tm_mon < 0 || tm->tm_mon > 11
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|| tm->tm_mday < 1 || tm->tm_mday > 31
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|| tm->tm_hour < 0 || tm->tm_hour > 23
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|| tm->tm_min < 0 || tm->tm_min > 59
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|| tm->tm_sec < 0 || tm->tm_sec > 60 /* mind the leap second */)
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return -1;
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/* Count the number of days */
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unsigned t = 365 * (tm->tm_year - 70)
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+ ydays[tm->tm_mon] + (tm->tm_mday - 1);
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/* TODO: unroll */
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for (int i = 70; i < tm->tm_year; i++)
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t += is_leap_year(1900 + i);
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if (tm->tm_mon > 1)
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t += is_leap_year(1900 + tm->tm_year);
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t *= 24;
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t += tm->tm_hour;
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t *= 60;
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t += tm->tm_min;
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t *= 60;
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t += tm->tm_sec;
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return t;
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}
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