diff options
author | gjb <gjb@FreeBSD.org> | 2013-10-09 17:07:20 +0000 |
---|---|---|
committer | gjb <gjb@FreeBSD.org> | 2013-10-09 17:07:20 +0000 |
commit | c5342bffee8407caeac0b651549206d534dfccb9 (patch) | |
tree | ca04a5cf90c8299963a38ecf5beb3ec437b5f1b1 /gnu/usr.bin/rcs/lib/maketime.c | |
parent | b33524a23e69ae8f48928d5b941a9a25a4609f30 (diff) | |
download | FreeBSD-src-c5342bffee8407caeac0b651549206d534dfccb9.zip FreeBSD-src-c5342bffee8407caeac0b651549206d534dfccb9.tar.gz |
Revert r256095, r256120 (partial), r256121:
r256095:
- Add gnu/usr.bin/rcs back to the base system.
r256120:
- Add WITHOUT_RCS back to src.conf.5.
r256121:
- Remove UPDATING entry regarding gnu/usr.bin/rcs removal.
Requested by: many
Approved by: re (marius)
Discussed with: core
Diffstat (limited to 'gnu/usr.bin/rcs/lib/maketime.c')
-rw-r--r-- | gnu/usr.bin/rcs/lib/maketime.c | 344 |
1 files changed, 344 insertions, 0 deletions
diff --git a/gnu/usr.bin/rcs/lib/maketime.c b/gnu/usr.bin/rcs/lib/maketime.c new file mode 100644 index 0000000..0f83bf5 --- /dev/null +++ b/gnu/usr.bin/rcs/lib/maketime.c @@ -0,0 +1,344 @@ +/* Convert struct partime into time_t. */ + +/* Copyright 1992, 1993, 1994, 1995 Paul Eggert + Distributed under license by the Free Software Foundation, Inc. + +This file is part of RCS. + +RCS is free software; you can redistribute it and/or modify +it under the terms of the GNU General Public License as published by +the Free Software Foundation; either version 2, or (at your option) +any later version. + +RCS is distributed in the hope that it will be useful, +but WITHOUT ANY WARRANTY; without even the implied warranty of +MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the +GNU General Public License for more details. + +You should have received a copy of the GNU General Public License +along with RCS; see the file COPYING. +If not, write to the Free Software Foundation, +59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. + +Report problems and direct all questions to: + + rcs-bugs@cs.purdue.edu + +*/ + +#if has_conf_h +# include "conf.h" +#else +# ifdef __STDC__ +# define P(x) x +# else +# define const +# define P(x) () +# endif +# include <stdlib.h> +# include <time.h> +#endif + +#include "partime.h" +#include "maketime.h" + +char const maketId[] + = "$FreeBSD$"; + +static int isleap P((int)); +static int month_days P((struct tm const*)); +static time_t maketime P((struct partime const*,time_t)); + +/* +* For maximum portability, use only localtime and gmtime. +* Make no assumptions about the time_t epoch or the range of time_t values. +* Avoid mktime because it's not universal and because there's no easy, +* portable way for mktime to yield the inverse of gmtime. +*/ + +#define TM_YEAR_ORIGIN 1900 + + static int +isleap(y) + int y; +{ + return (y&3) == 0 && (y%100 != 0 || y%400 == 0); +} + +static int const month_yday[] = { + /* days in year before start of months 0-12 */ + 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 +}; + +/* Yield the number of days in TM's month. */ + static int +month_days(tm) + struct tm const *tm; +{ + int m = tm->tm_mon; + return month_yday[m+1] - month_yday[m] + + (m==1 && isleap(tm->tm_year + TM_YEAR_ORIGIN)); +} + +/* +* Convert UNIXTIME to struct tm form. +* Use gmtime if available and if !LOCALZONE, localtime otherwise. +*/ + struct tm * +time2tm(unixtime, localzone) + time_t unixtime; + int localzone; +{ + struct tm *tm; +# if TZ_must_be_set + static char const *TZ; + if (!TZ && !(TZ = getenv("TZ"))) + faterror("The TZ environment variable is not set; please set it to your timezone"); +# endif + if (localzone || !(tm = gmtime(&unixtime))) + tm = localtime(&unixtime); + return tm; +} + +/* Yield A - B, measured in seconds. */ + time_t +difftm(a, b) + struct tm const *a, *b; +{ + int ay = a->tm_year + (TM_YEAR_ORIGIN - 1); + int by = b->tm_year + (TM_YEAR_ORIGIN - 1); + int difference_in_day_of_year = a->tm_yday - b->tm_yday; + int intervening_leap_days = ( + ((ay >> 2) - (by >> 2)) + - (ay/100 - by/100) + + ((ay/100 >> 2) - (by/100 >> 2)) + ); + time_t difference_in_years = ay - by; + time_t difference_in_days = ( + difference_in_years*365 + + (intervening_leap_days + difference_in_day_of_year) + ); + return + ( + ( + 24*difference_in_days + + (a->tm_hour - b->tm_hour) + )*60 + (a->tm_min - b->tm_min) + )*60 + (a->tm_sec - b->tm_sec); +} + +/* +* Adjust time T by adding SECONDS. SECONDS must be at most 24 hours' worth. +* Adjust only T's year, mon, mday, hour, min and sec members; +* plus adjust wday if it is defined. +*/ + void +adjzone(t, seconds) + register struct tm *t; + long seconds; +{ + /* + * This code can be off by a second if SECONDS is not a multiple of 60, + * if T is local time, and if a leap second happens during this minute. + * But this bug has never occurred, and most likely will not ever occur. + * Liberia, the last country for which SECONDS % 60 was nonzero, + * switched to UTC in May 1972; the first leap second was in June 1972. + */ + int leap_second = t->tm_sec == 60; + long sec = seconds + (t->tm_sec - leap_second); + if (sec < 0) { + if ((t->tm_min -= (59-sec)/60) < 0) { + if ((t->tm_hour -= (59-t->tm_min)/60) < 0) { + t->tm_hour += 24; + if (TM_DEFINED(t->tm_wday) && --t->tm_wday < 0) + t->tm_wday = 6; + if (--t->tm_mday <= 0) { + if (--t->tm_mon < 0) { + --t->tm_year; + t->tm_mon = 11; + } + t->tm_mday = month_days(t); + } + } + t->tm_min += 24 * 60; + } + sec += 24L * 60 * 60; + } else + if (60 <= (t->tm_min += sec/60)) + if (24 <= (t->tm_hour += t->tm_min/60)) { + t->tm_hour -= 24; + if (TM_DEFINED(t->tm_wday) && ++t->tm_wday == 7) + t->tm_wday = 0; + if (month_days(t) < ++t->tm_mday) { + if (11 < ++t->tm_mon) { + ++t->tm_year; + t->tm_mon = 0; + } + t->tm_mday = 1; + } + } + t->tm_min %= 60; + t->tm_sec = (int) (sec%60) + leap_second; +} + +/* +* Convert TM to time_t, using localtime if LOCALZONE and gmtime otherwise. +* Use only TM's year, mon, mday, hour, min, and sec members. +* Ignore TM's old tm_yday and tm_wday, but fill in their correct values. +* Yield -1 on failure (e.g. a member out of range). +* Posix 1003.1-1990 doesn't allow leap seconds, but some implementations +* have them anyway, so allow them if localtime/gmtime does. +*/ + time_t +tm2time(tm, localzone) + struct tm *tm; + int localzone; +{ + /* Cache the most recent t,tm pairs; 1 for gmtime, 1 for localtime. */ + static time_t t_cache[2]; + static struct tm tm_cache[2]; + + time_t d, gt; + struct tm const *gtm; + /* + * The maximum number of iterations should be enough to handle any + * combinations of leap seconds, time zone rule changes, and solar time. + * 4 is probably enough; we use a bigger number just to be safe. + */ + int remaining_tries = 8; + + /* Avoid subscript errors. */ + if (12 <= (unsigned)tm->tm_mon) + return -1; + + tm->tm_yday = month_yday[tm->tm_mon] + tm->tm_mday + - (tm->tm_mon<2 || ! isleap(tm->tm_year + TM_YEAR_ORIGIN)); + + /* Make a first guess. */ + gt = t_cache[localzone]; + gtm = gt ? &tm_cache[localzone] : time2tm(gt,localzone); + + /* Repeatedly use the error from the guess to improve the guess. */ + while ((d = difftm(tm, gtm)) != 0) { + if (--remaining_tries == 0) + return -1; + gt += d; + gtm = time2tm(gt,localzone); + } + t_cache[localzone] = gt; + tm_cache[localzone] = *gtm; + + /* + * Check that the guess actually matches; + * overflow can cause difftm to yield 0 even on differing times, + * or tm may have members out of range (e.g. bad leap seconds). + */ + if ( (tm->tm_year ^ gtm->tm_year) + | (tm->tm_mon ^ gtm->tm_mon) + | (tm->tm_mday ^ gtm->tm_mday) + | (tm->tm_hour ^ gtm->tm_hour) + | (tm->tm_min ^ gtm->tm_min) + | (tm->tm_sec ^ gtm->tm_sec)) + return -1; + + tm->tm_wday = gtm->tm_wday; + return gt; +} + +/* +* Check *PT and convert it to time_t. +* If it is incompletely specified, use DEFAULT_TIME to fill it out. +* Use localtime if PT->zone is the special value TM_LOCAL_ZONE. +* Yield -1 on failure. +* ISO 8601 day-of-year and week numbers are not yet supported. +*/ + static time_t +maketime(pt, default_time) + struct partime const *pt; + time_t default_time; +{ + int localzone, wday; + struct tm tm; + struct tm *tm0 = 0; + time_t r; + + tm0 = 0; /* Keep gcc -Wall happy. */ + localzone = pt->zone==TM_LOCAL_ZONE; + + tm = pt->tm; + + if (TM_DEFINED(pt->ymodulus) || !TM_DEFINED(tm.tm_year)) { + /* Get tm corresponding to current time. */ + tm0 = time2tm(default_time, localzone); + if (!localzone) + adjzone(tm0, pt->zone); + } + + if (TM_DEFINED(pt->ymodulus)) + tm.tm_year += + (tm0->tm_year + TM_YEAR_ORIGIN)/pt->ymodulus * pt->ymodulus; + else if (!TM_DEFINED(tm.tm_year)) { + /* Set default year, month, day from current time. */ + tm.tm_year = tm0->tm_year + TM_YEAR_ORIGIN; + if (!TM_DEFINED(tm.tm_mon)) { + tm.tm_mon = tm0->tm_mon; + if (!TM_DEFINED(tm.tm_mday)) + tm.tm_mday = tm0->tm_mday; + } + } + + /* Convert from partime year (Gregorian) to Posix year. */ + tm.tm_year -= TM_YEAR_ORIGIN; + + /* Set remaining default fields to be their minimum values. */ + if (!TM_DEFINED(tm.tm_mon)) tm.tm_mon = 0; + if (!TM_DEFINED(tm.tm_mday)) tm.tm_mday = 1; + if (!TM_DEFINED(tm.tm_hour)) tm.tm_hour = 0; + if (!TM_DEFINED(tm.tm_min)) tm.tm_min = 0; + if (!TM_DEFINED(tm.tm_sec)) tm.tm_sec = 0; + + if (!localzone) + adjzone(&tm, -pt->zone); + wday = tm.tm_wday; + + /* Convert and fill in the rest of the tm. */ + r = tm2time(&tm, localzone); + + /* Check weekday. */ + if (r != -1 && TM_DEFINED(wday) && wday != tm.tm_wday) + return -1; + + return r; +} + +/* Parse a free-format date in SOURCE, yielding a Unix format time. */ + time_t +str2time(source, default_time, default_zone) + char const *source; + time_t default_time; + long default_zone; +{ + struct partime pt; + + if (*partime(source, &pt)) + return -1; + if (pt.zone == TM_UNDEFINED_ZONE) + pt.zone = default_zone; + return maketime(&pt, default_time); +} + +#if TEST +#include <stdio.h> + int +main(argc, argv) int argc; char **argv; +{ + time_t default_time = time((time_t *)0); + long default_zone = argv[1] ? atol(argv[1]) : 0; + char buf[1000]; + while (fgets(buf, 1000, stdin)) { + time_t t = str2time(buf, default_time, default_zone); + printf("%s", asctime(gmtime(&t))); + } + return 0; +} +#endif |