| Vishal Bhoj | 82c8071 | 2015-12-15 21:13:33 +0530 | [diff] [blame^] | 1 | /** @file
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| 2 | timegm implementation
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| 3 |
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| 4 | Copyright (c) 2011, Intel Corporation. All rights reserved.<BR>
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| 5 | This program and the accompanying materials are licensed and made available under
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| 6 | the terms and conditions of the BSD License that accompanies this distribution.
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| 7 | The full text of the license may be found at
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| 8 | http://opensource.org/licenses/bsd-license.php.
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| 9 |
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| 10 | THE PROGRAM IS DISTRIBUTED UNDER THE BSD LICENSE ON AN "AS IS" BASIS,
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| 11 | WITHOUT WARRANTIES OR REPRESENTATIONS OF ANY KIND, EITHER EXPRESS OR IMPLIED.
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| 12 |
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| 13 | * Copyright (c) 1987, 1989 Regents of the University of California.
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| 14 | * All rights reserved.
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| 15 | *
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| 16 | * This code is derived from software contributed to Berkeley by
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| 17 | * Arthur David Olson of the National Cancer Institute.
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| 18 | *
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| 19 | * Redistribution and use in source and binary forms, with or without
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| 20 | * modification, are permitted provided that the following conditions
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| 21 | * are met:
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| 22 | * 1. Redistributions of source code must retain the above copyright
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| 23 | * notice, this list of conditions and the following disclaimer.
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| 24 | * 2. Redistributions in binary form must reproduce the above copyright
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| 25 | * notice, this list of conditions and the following disclaimer in the
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| 26 | * documentation and/or other materials provided with the distribution.
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| 27 | * 3. All advertising materials mentioning features or use of this software
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| 28 | * must display the following acknowledgement:
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| 29 | * This product includes software developed by the University of
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| 30 | * California, Berkeley and its contributors.
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| 31 | * 4. Neither the name of the University nor the names of its contributors
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| 32 | * may be used to endorse or promote products derived from this software
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| 33 | * without specific prior written permission.
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| 34 | *
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| 35 | * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
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| 36 | * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
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| 37 | * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
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| 38 | * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
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| 39 | * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
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| 40 | * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
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| 41 | * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
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| 42 | * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
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| 43 | * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
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| 44 | * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
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| 45 | * SUCH DAMAGE.
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| 46 |
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| 47 | static char *sccsid = "from: @(#)ctime.c 5.26 (Berkeley) 2/23/91";
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| 48 |
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| 49 |
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| 50 | * This implementation of mktime is lifted straight from the NetBSD (BSD 4.4)
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| 51 | * version. I modified it slightly to divorce it from the internals of the
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| 52 | * ctime library. Thus this version can't use details of the internal
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| 53 | * timezone state file to figure out strange unnormalized struct tm values,
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| 54 | * as might result from someone doing date math on the tm struct then passing
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| 55 | * it to mktime.
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| 56 | *
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| 57 | * It just does as well as it can at normalizing the tm input, then does a
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| 58 | * binary search of the time space using the system's localtime() function.
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| 59 | *
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| 60 | * The original binary search was defective in that it didn't consider the
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| 61 | * setting of tm_isdst when comparing tm values, causing the search to be
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| 62 | * flubbed for times near the dst/standard time changeover. The original
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| 63 | * code seems to make up for this by grubbing through the timezone info
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| 64 | * whenever the binary search barfed. Since I don't have that luxury in
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| 65 | * portable code, I have to take care of tm_isdst in the comparison routine.
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| 66 | * This requires knowing how many minutes offset dst is from standard time.
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| 67 | *
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| 68 | * So, if you live somewhere in the world where dst is not 60 minutes offset,
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| 69 | * and your vendor doesn't supply mktime(), you'll have to edit this variable
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| 70 | * by hand. Sorry about that.
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| 71 |
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| 72 | $NetBSD: mktime.c,v 1.4 2006/06/11 19:34:10 kardel Exp $
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| 73 | **/
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| 74 |
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| 75 | #include <LibConfig.h>
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| 76 | #include <time.h>
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| 77 |
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| 78 | /*
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| 79 | This funciton is in Time.c, which has a different license than timegm.
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| 80 | */
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| 81 | time_t
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| 82 | time2(struct tm * const tmp, void (* const funcp)(const time_t*, long, struct tm*),
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| 83 | const long offset, int * const okayp);
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| 84 |
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| 85 | /*
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| 86 | This funciton is in Time.c, which has a different license than timegm.
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| 87 | */
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| 88 | void
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| 89 | gmtsub(
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| 90 | const time_t * const timep,
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| 91 | const long offset,
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| 92 | struct tm * const tmp
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| 93 | );
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| 94 |
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| 95 | #ifndef WRONG
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| 96 | #define WRONG (-1)
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| 97 | #endif /* !defined WRONG */
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| 98 |
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| 99 | /*
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| 100 | Convert a tm structure to a GMT based time_t.
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| 101 | */
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| 102 | time_t timegm( struct tm * tmp )
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| 103 | {
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| 104 | register time_t t;
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| 105 | int okay;
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| 106 |
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| 107 | tmp->tm_isdst = 0;
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| 108 | t = time2(tmp, gmtsub, 0, &okay);
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| 109 | if (okay || tmp->tm_isdst < 0)
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| 110 | return t;
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| 111 |
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| 112 | return WRONG;
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| 113 | } |