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Diffstat (limited to 'debian/htdig/htdig-3.2.0b6/htlib/mktime.c')
| -rw-r--r-- | debian/htdig/htdig-3.2.0b6/htlib/mktime.c | 535 |
1 files changed, 535 insertions, 0 deletions
diff --git a/debian/htdig/htdig-3.2.0b6/htlib/mktime.c b/debian/htdig/htdig-3.2.0b6/htlib/mktime.c new file mode 100644 index 00000000..a59dab4c --- /dev/null +++ b/debian/htdig/htdig-3.2.0b6/htlib/mktime.c @@ -0,0 +1,535 @@ +/* Part of the ht://Dig package <http://www.htdig.org/> */ +/* Copyright (c) 1999-2004 The ht://Dig Group */ +/* For copyright details, see the file COPYING in your distribution */ +/* or the GNU Library General Public License (LGPL) version 2 or later */ +/* <http://www.gnu.org/copyleft/lgpl.html> */ + + +/* Convert a `struct tm' to a time_t value. + Copyright (C) 1993, 94, 95, 96, 97, 98, 99 Free Software Foundation, Inc. + This file is part of the GNU C Library. + Contributed by Paul Eggert ([email protected]). + + The GNU C Library is free software; you can redistribute it and/or + modify it under the terms of the GNU Library General Public License as + published by the Free Software Foundation; either version 2 of the + License, or (at your option) any later version. + + The GNU C Library 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 + Library General Public License for more details. + + You should have received a copy of the GNU Library General Public + License along with the GNU C Library; see the file COPYING.LIB. If not, + write to the Free Software Foundation, Inc., 59 Temple Place - Suite 330, + Boston, MA 02111-1307, USA. */ + +/* Define this to have a standalone program to test this implementation of + mktime. */ +/* #define DEBUG 1 */ + +#ifdef HAVE_CONFIG_H +#include "htconfig.h" +#endif + +#ifdef _LIBC +# define HAVE_LIMITS_H 1 +# define STDC_HEADERS 1 +#endif + +/* Assume that leap seconds are possible, unless told otherwise. + If the host has a `zic' command with a `-L leapsecondfilename' option, + then it supports leap seconds; otherwise it probably doesn't. */ +#ifndef LEAP_SECONDS_POSSIBLE +# define LEAP_SECONDS_POSSIBLE 1 +#endif + +#include <sys/types.h> /* Some systems define `time_t' here. */ +#include <time.h> + +#if HAVE_LIMITS_H +# include <limits.h> +#endif + +#if DEBUG +# include <stdio.h> +# if STDC_HEADERS +# include <stdlib.h> +# endif +/* Make it work even if the system's libc has its own mktime routine. */ +# define mktime my_mktime +#endif /* DEBUG */ + +#ifndef __P +# if defined __GNUC__ || (defined __STDC__ && __STDC__) +# define __P(args) args +# else +# define __P(args) () +# endif /* GCC. */ +#endif /* Not __P. */ + +#ifndef CHAR_BIT +# define CHAR_BIT 8 +#endif + +/* The extra casts work around common compiler bugs. */ +#define TYPE_SIGNED(t) (! ((t) 0 < (t) -1)) +/* The outer cast is needed to work around a bug in Cray C 5.0.3.0. + It is necessary at least when t == time_t. */ +#define TYPE_MINIMUM(t) ((t) (TYPE_SIGNED (t) \ + ? ~ (t) 0 << (sizeof (t) * CHAR_BIT - 1) : (t) 0)) +#define TYPE_MAXIMUM(t) ((t) (~ (t) 0 - TYPE_MINIMUM (t))) + +#ifndef INT_MIN +# define INT_MIN TYPE_MINIMUM (int) +#endif +#ifndef INT_MAX +# define INT_MAX TYPE_MAXIMUM (int) +#endif + +#ifndef TIME_T_MIN +# define TIME_T_MIN TYPE_MINIMUM (time_t) +#endif +#ifndef TIME_T_MAX +# define TIME_T_MAX TYPE_MAXIMUM (time_t) +#endif + +#define TM_YEAR_BASE 1900 +#define EPOCH_YEAR 1970 + +#ifndef __isleap +/* Nonzero if YEAR is a leap year (every 4 years, + except every 100th isn't, and every 400th is). */ +# define __isleap(year) \ + ((year) % 4 == 0 && ((year) % 100 != 0 || (year) % 400 == 0)) +#endif + +/* How many days come before each month (0-12). */ +const unsigned short int __mon_yday[2][13] = + { + /* Normal years. */ + { 0, 31, 59, 90, 120, 151, 181, 212, 243, 273, 304, 334, 365 }, + /* Leap years. */ + { 0, 31, 60, 91, 121, 152, 182, 213, 244, 274, 305, 335, 366 } + }; + + +#ifdef _LIBC +# define my_mktime_localtime_r __localtime_r +#else +/* If we're a mktime substitute in a GNU program, then prefer + localtime to localtime_r, since many localtime_r implementations + are buggy. */ +static struct tm * +my_mktime_localtime_r (const time_t *t, struct tm *tp) +{ + struct tm *l = localtime (t); + if (! l) + return 0; + *tp = *l; + return tp; +} +#endif /* ! _LIBC */ + + +/* Yield the difference between (YEAR-YDAY HOUR:MIN:SEC) and (*TP), + measured in seconds, ignoring leap seconds. + YEAR uses the same numbering as TM->tm_year. + All values are in range, except possibly YEAR. + If TP is null, return a nonzero value. + If overflow occurs, yield the low order bits of the correct answer. */ +static time_t +ydhms_tm_diff (int year, int yday, int hour, int min, int sec, + const struct tm *tp) +{ + if (!tp) + return 1; + else + { + /* Compute intervening leap days correctly even if year is negative. + Take care to avoid int overflow. time_t overflow is OK, since + only the low order bits of the correct time_t answer are needed. + Don't convert to time_t until after all divisions are done, since + time_t might be unsigned. */ + int a4 = (year >> 2) + (TM_YEAR_BASE >> 2) - ! (year & 3); + int b4 = (tp->tm_year >> 2) + (TM_YEAR_BASE >> 2) - ! (tp->tm_year & 3); + int a100 = a4 / 25 - (a4 % 25 < 0); + int b100 = b4 / 25 - (b4 % 25 < 0); + int a400 = a100 >> 2; + int b400 = b100 >> 2; + int intervening_leap_days = (a4 - b4) - (a100 - b100) + (a400 - b400); + time_t years = year - (time_t) tp->tm_year; + time_t days = (365 * years + intervening_leap_days + + (yday - tp->tm_yday)); + return (60 * (60 * (24 * days + (hour - tp->tm_hour)) + + (min - tp->tm_min)) + + (sec - tp->tm_sec)); + } +} + +/* Use CONVERT to convert *T to a broken down time in *TP. + If *T is out of range for conversion, adjust it so that + it is the nearest in-range value and then convert that. */ +static struct tm * +ranged_convert (struct tm *(*convert) (const time_t *, struct tm *), + time_t *t, struct tm *tp) +{ + struct tm *r; + + if (! (r = (*convert) (t, tp)) && *t) + { + time_t bad = *t; + time_t ok = 0; + struct tm tm; + + /* BAD is a known unconvertible time_t, and OK is a known good one. + Use binary search to narrow the range between BAD and OK until + they differ by 1. */ + while (bad != ok + (bad < 0 ? -1 : 1)) + { + time_t mid = *t = (bad < 0 + ? bad + ((ok - bad) >> 1) + : ok + ((bad - ok) >> 1)); + if ((r = (*convert) (t, tp))) + { + tm = *r; + ok = mid; + } + else + bad = mid; + } + + if (!r && ok) + { + /* The last conversion attempt failed; + revert to the most recent successful attempt. */ + *t = ok; + *tp = tm; + r = tp; + } + } + + return r; +} + + +/* Convert *TP to a time_t value, inverting + the monotonic and mostly-unit-linear conversion function CONVERT. + Use *OFFSET to keep track of a guess at the offset of the result, + compared to what the result would be for UTC without leap seconds. + If *OFFSET's guess is correct, only one CONVERT call is needed. */ +time_t +__mktime_internal (struct tm *tp, + struct tm *(*convert) (const time_t *, struct tm *), + time_t *offset) +{ + time_t t, dt, t0, t1, t2; + struct tm tm; + + /* The maximum number of probes (calls to CONVERT) should be enough + to handle any combinations of time zone rule changes, solar time, + leap seconds, and oscillations around a spring-forward gap. + POSIX.1 prohibits leap seconds, but some hosts have them anyway. */ + int remaining_probes = 6; + + /* Time requested. Copy it in case CONVERT modifies *TP; this can + occur if TP is localtime's returned value and CONVERT is localtime. */ + int sec = tp->tm_sec; + int min = tp->tm_min; + int hour = tp->tm_hour; + int mday = tp->tm_mday; + int mon = tp->tm_mon; + int year_requested = tp->tm_year; + int isdst = tp->tm_isdst; + + /* Ensure that mon is in range, and set year accordingly. */ + int mon_remainder = mon % 12; + int negative_mon_remainder = mon_remainder < 0; + int mon_years = mon / 12 - negative_mon_remainder; + int year = year_requested + mon_years; + + /* The other values need not be in range: + the remaining code handles minor overflows correctly, + assuming int and time_t arithmetic wraps around. + Major overflows are caught at the end. */ + + /* Calculate day of year from year, month, and day of month. + The result need not be in range. */ + int yday = ((__mon_yday[__isleap (year + TM_YEAR_BASE)] + [mon_remainder + 12 * negative_mon_remainder]) + + mday - 1); + + int sec_requested = sec; +#if LEAP_SECONDS_POSSIBLE + /* Handle out-of-range seconds specially, + since ydhms_tm_diff assumes every minute has 60 seconds. */ + if (sec < 0) + sec = 0; + if (59 < sec) + sec = 59; +#endif + + /* Invert CONVERT by probing. First assume the same offset as last time. + Then repeatedly use the error to improve the guess. */ + + tm.tm_year = EPOCH_YEAR - TM_YEAR_BASE; + tm.tm_yday = tm.tm_hour = tm.tm_min = tm.tm_sec = 0; + t0 = ydhms_tm_diff (year, yday, hour, min, sec, &tm); + + for (t = t1 = t2 = t0 + *offset; + (dt = ydhms_tm_diff (year, yday, hour, min, sec, + ranged_convert (convert, &t, &tm))); + t1 = t2, t2 = t, t += dt) + if (t == t1 && t != t2 + && (isdst < 0 || tm.tm_isdst < 0 + || (isdst != 0) != (tm.tm_isdst != 0))) + /* We can't possibly find a match, as we are oscillating + between two values. The requested time probably falls + within a spring-forward gap of size DT. Follow the common + practice in this case, which is to return a time that is DT + away from the requested time, preferring a time whose + tm_isdst differs from the requested value. In practice, + this is more useful than returning -1. */ + break; + else if (--remaining_probes == 0) + return -1; + + /* If we have a match, check whether tm.tm_isdst has the requested + value, if any. */ + if (dt == 0 && isdst != tm.tm_isdst && 0 <= isdst && 0 <= tm.tm_isdst) + { + /* tm.tm_isdst has the wrong value. Look for a neighboring + time with the right value, and use its UTC offset. + Heuristic: probe the previous three calendar quarters (approximately), + looking for the desired isdst. This isn't perfect, + but it's good enough in practice. */ + int quarter = 7889238; /* seconds per average 1/4 Gregorian year */ + int i; + + /* If we're too close to the time_t limit, look in future quarters. */ + if (t < TIME_T_MIN + 3 * quarter) + quarter = -quarter; + + for (i = 1; i <= 3; i++) + { + time_t ot = t - i * quarter; + struct tm otm; + ranged_convert (convert, &ot, &otm); + if (otm.tm_isdst == isdst) + { + /* We found the desired tm_isdst. + Extrapolate back to the desired time. */ + t = ot + ydhms_tm_diff (year, yday, hour, min, sec, &otm); + ranged_convert (convert, &t, &tm); + break; + } + } + } + + *offset = t - t0; + +#if LEAP_SECONDS_POSSIBLE + if (sec_requested != tm.tm_sec) + { + /* Adjust time to reflect the tm_sec requested, not the normalized value. + Also, repair any damage from a false match due to a leap second. */ + t += sec_requested - sec + (sec == 0 && tm.tm_sec == 60); + if (! (*convert) (&t, &tm)) + return -1; + } +#endif + + if (TIME_T_MAX / INT_MAX / 366 / 24 / 60 / 60 < 3) + { + /* time_t isn't large enough to rule out overflows in ydhms_tm_diff, + so check for major overflows. A gross check suffices, + since if t has overflowed, it is off by a multiple of + TIME_T_MAX - TIME_T_MIN + 1. So ignore any component of + the difference that is bounded by a small value. */ + + double dyear = (double) year_requested + mon_years - tm.tm_year; + double dday = 366 * dyear + mday; + double dsec = 60 * (60 * (24 * dday + hour) + min) + sec_requested; + + /* On Irix4.0.5 cc, dividing TIME_T_MIN by 3 does not produce + correct results, ie., it erroneously gives a positive value + of 715827882. Setting a variable first then doing math on it + seems to work. ([email protected]) */ + + const time_t time_t_max = TIME_T_MAX; + const time_t time_t_min = TIME_T_MIN; + + if (time_t_max / 3 - time_t_min / 3 < (dsec < 0 ? - dsec : dsec)) + return -1; + } + + *tp = tm; + return t; +} + + +static time_t localtime_offset; + +/* Convert *TP to a time_t value. */ +time_t +mymktime (tp) + struct tm *tp; +{ +#ifdef _LIBC + /* POSIX.1 8.1.1 requires that whenever mktime() is called, the + time zone names contained in the external variable `tzname' shall + be set as if the tzset() function had been called. */ + __tzset (); +#endif + + return __mktime_internal (tp, my_mktime_localtime_r, &localtime_offset); +} + +#ifdef weak_alias +weak_alias (mktime, timelocal) +#endif + +#if DEBUG + +static int +not_equal_tm (a, b) + struct tm *a; + struct tm *b; +{ + return ((a->tm_sec ^ b->tm_sec) + | (a->tm_min ^ b->tm_min) + | (a->tm_hour ^ b->tm_hour) + | (a->tm_mday ^ b->tm_mday) + | (a->tm_mon ^ b->tm_mon) + | (a->tm_year ^ b->tm_year) + | (a->tm_mday ^ b->tm_mday) + | (a->tm_yday ^ b->tm_yday) + | (a->tm_isdst ^ b->tm_isdst)); +} + +static void +print_tm (tp) + struct tm *tp; +{ + if (tp) + printf ("%04d-%02d-%02d %02d:%02d:%02d yday %03d wday %d isdst %d", + tp->tm_year + TM_YEAR_BASE, tp->tm_mon + 1, tp->tm_mday, + tp->tm_hour, tp->tm_min, tp->tm_sec, + tp->tm_yday, tp->tm_wday, tp->tm_isdst); + else + printf ("0"); +} + +static int +check_result (tk, tmk, tl, lt) + time_t tk; + struct tm tmk; + time_t tl; + struct tm *lt; +{ + if (tk != tl || !lt || not_equal_tm (&tmk, lt)) + { + printf ("mktime ("); + print_tm (&tmk); + printf (")\nyields ("); + print_tm (lt); + printf (") == %ld, should be %ld\n", (long) tl, (long) tk); + return 1; + } + + return 0; +} + +int +main (argc, argv) + int argc; + char **argv; +{ + int status = 0; + struct tm tm, tmk, tml; + struct tm *lt; + time_t tk, tl; + char trailer; + + if ((argc == 3 || argc == 4) + && (sscanf (argv[1], "%d-%d-%d%c", + &tm.tm_year, &tm.tm_mon, &tm.tm_mday, &trailer) + == 3) + && (sscanf (argv[2], "%d:%d:%d%c", + &tm.tm_hour, &tm.tm_min, &tm.tm_sec, &trailer) + == 3)) + { + tm.tm_year -= TM_YEAR_BASE; + tm.tm_mon--; + tm.tm_isdst = argc == 3 ? -1 : atoi (argv[3]); + tmk = tm; + tl = mktime (&tmk); + lt = localtime (&tl); + if (lt) + { + tml = *lt; + lt = &tml; + } + printf ("mktime returns %ld == ", (long) tl); + print_tm (&tmk); + printf ("\n"); + status = check_result (tl, tmk, tl, lt); + } + else if (argc == 4 || (argc == 5 && strcmp (argv[4], "-") == 0)) + { + time_t from = atol (argv[1]); + time_t by = atol (argv[2]); + time_t to = atol (argv[3]); + + if (argc == 4) + for (tl = from; tl <= to; tl += by) + { + lt = localtime (&tl); + if (lt) + { + tmk = tml = *lt; + tk = mktime (&tmk); + status |= check_result (tk, tmk, tl, tml); + } + else + { + printf ("localtime (%ld) yields 0\n", (long) tl); + status = 1; + } + } + else + for (tl = from; tl <= to; tl += by) + { + /* Null benchmark. */ + lt = localtime (&tl); + if (lt) + { + tmk = tml = *lt; + tk = tl; + status |= check_result (tk, tmk, tl, tml); + } + else + { + printf ("localtime (%ld) yields 0\n", (long) tl); + status = 1; + } + } + } + else + printf ("Usage:\ +\t%s YYYY-MM-DD HH:MM:SS [ISDST] # Test given time.\n\ +\t%s FROM BY TO # Test values FROM, FROM+BY, ..., TO.\n\ +\t%s FROM BY TO - # Do not test those values (for benchmark).\n", + argv[0], argv[0], argv[0]); + + return status; +} + +#endif /* DEBUG */ + +/* +Local Variables: +compile-command: "gcc -DDEBUG -DHAVE_LIMITS_H -DSTDC_HEADERS -Wall -W -O -g mktime.c -o mktime" +End: +*/ |