diff options
Diffstat (limited to 'src/gl/time_rz.c')
| -rw-r--r-- | src/gl/time_rz.c | 322 |
1 files changed, 0 insertions, 322 deletions
diff --git a/src/gl/time_rz.c b/src/gl/time_rz.c deleted file mode 100644 index 38afb5fc3c..0000000000 --- a/src/gl/time_rz.c +++ /dev/null @@ -1,322 +0,0 @@ -/* Time zone functions such as tzalloc and localtime_rz - - Copyright 2015-2016 Free Software Foundation, Inc. - - This program 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 3, or (at your option) - any later version. - - This program 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 this program; if not, see <http://www.gnu.org/licenses/>. */ - -/* Written by Paul Eggert. */ - -/* Although this module is not thread-safe, any races should be fairly - rare and reasonably benign. For complete thread-safety, use a C - library with a working timezone_t type, so that this module is not - needed. */ - -#include <config.h> - -#include <time.h> - -#include <errno.h> -#include <stdbool.h> -#include <stddef.h> -#include <stdlib.h> -#include <string.h> - -#include "flexmember.h" -#include "time-internal.h" - -#if !HAVE_TZSET -static void tzset (void) { } -#endif - -/* The approximate size to use for small allocation requests. This is - the largest "small" request for the GNU C library malloc. */ -enum { DEFAULT_MXFAST = 64 * sizeof (size_t) / 4 }; - -/* Minimum size of the ABBRS member of struct abbr. ABBRS is larger - only in the unlikely case where an abbreviation longer than this is - used. */ -enum { ABBR_SIZE_MIN = DEFAULT_MXFAST - offsetof (struct tm_zone, abbrs) }; - -/* Magic cookie timezone_t value, for local time. It differs from - NULL and from all other timezone_t values. Only the address - matters; the pointer is never dereferenced. */ -static timezone_t const local_tz = (timezone_t) 1; - -#if HAVE_TM_ZONE || HAVE_TZNAME - -/* Return true if the values A and B differ according to the rules for - tm_isdst: A and B differ if one is zero and the other positive. */ -static bool -isdst_differ (int a, int b) -{ - return !a != !b && 0 <= a && 0 <= b; -} - -/* Return true if A and B are equal. */ -static int -equal_tm (const struct tm *a, const 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) - | isdst_differ (a->tm_isdst, b->tm_isdst)); -} - -#endif - -/* Copy to ABBRS the abbreviation at ABBR with size ABBR_SIZE (this - includes its trailing null byte). Append an extra null byte to - mark the end of ABBRS. */ -static void -extend_abbrs (char *abbrs, char const *abbr, size_t abbr_size) -{ - memcpy (abbrs, abbr, abbr_size); - abbrs[abbr_size] = '\0'; -} - -/* Return a newly allocated time zone for NAME, or NULL on failure. - A null NAME stands for wall clock time (which is like unset TZ). */ -timezone_t -tzalloc (char const *name) -{ - size_t name_size = name ? strlen (name) + 1 : 0; - size_t abbr_size = name_size < ABBR_SIZE_MIN ? ABBR_SIZE_MIN : name_size + 1; - timezone_t tz = malloc (FLEXSIZEOF (struct tm_zone, abbrs, abbr_size)); - if (tz) - { - tz->next = NULL; -#if HAVE_TZNAME && !HAVE_TM_ZONE - tz->tzname_copy[0] = tz->tzname_copy[1] = NULL; -#endif - tz->tz_is_set = !!name; - tz->abbrs[0] = '\0'; - if (name) - extend_abbrs (tz->abbrs, name, name_size); - } - return tz; -} - -/* Save into TZ any nontrivial time zone abbreviation used by TM, and - update *TM (if HAVE_TM_ZONE) or *TZ (if !HAVE_TM_ZONE && - HAVE_TZNAME) if they use the abbreviation. Return true if - successful, false (setting errno) otherwise. */ -static bool -save_abbr (timezone_t tz, struct tm *tm) -{ -#if HAVE_TM_ZONE || HAVE_TZNAME - char const *zone = NULL; - char *zone_copy = (char *) ""; - -# if HAVE_TZNAME - int tzname_index = -1; -# endif - -# if HAVE_TM_ZONE - zone = tm->tm_zone; -# endif - -# if HAVE_TZNAME - if (! (zone && *zone) && 0 <= tm->tm_isdst) - { - tzname_index = tm->tm_isdst != 0; - zone = tzname[tzname_index]; - } -# endif - - /* No need to replace null zones, or zones within the struct tm. */ - if (!zone || ((char *) tm <= zone && zone < (char *) (tm + 1))) - return true; - - if (*zone) - { - zone_copy = tz->abbrs; - - while (strcmp (zone_copy, zone) != 0) - { - if (! (*zone_copy || (zone_copy == tz->abbrs && tz->tz_is_set))) - { - size_t zone_size = strlen (zone) + 1; - if (zone_size < tz->abbrs + ABBR_SIZE_MIN - zone_copy) - extend_abbrs (zone_copy, zone, zone_size); - else - { - tz = tz->next = tzalloc (zone); - if (!tz) - return false; - tz->tz_is_set = 0; - zone_copy = tz->abbrs; - } - break; - } - - zone_copy += strlen (zone_copy) + 1; - if (!*zone_copy && tz->next) - { - tz = tz->next; - zone_copy = tz->abbrs; - } - } - } - - /* Replace the zone name so that its lifetime matches that of TZ. */ -# if HAVE_TM_ZONE - tm->tm_zone = zone_copy; -# else - if (0 <= tzname_index) - tz->tzname_copy[tzname_index] = zone_copy; -# endif -#endif - - return true; -} - -/* Free a time zone. */ -void -tzfree (timezone_t tz) -{ - if (tz != local_tz) - while (tz) - { - timezone_t next = tz->next; - free (tz); - tz = next; - } -} - -/* Get and set the TZ environment variable. These functions can be - overridden by programs like Emacs that manage their own environment. */ - -#ifndef getenv_TZ -static char * -getenv_TZ (void) -{ - return getenv ("TZ"); -} -#endif - -#ifndef setenv_TZ -static int -setenv_TZ (char const *tz) -{ - return tz ? setenv ("TZ", tz, 1) : unsetenv ("TZ"); -} -#endif - -/* Change the environment to match the specified timezone_t value. - Return true if successful, false (setting errno) otherwise. */ -static bool -change_env (timezone_t tz) -{ - if (setenv_TZ (tz->tz_is_set ? tz->abbrs : NULL) != 0) - return false; - tzset (); - return true; -} - -/* Temporarily set the time zone to TZ, which must not be null. - Return LOCAL_TZ if the time zone setting is already correct. - Otherwise return a newly allocated time zone representing the old - setting, or NULL (setting errno) on failure. */ -static timezone_t -set_tz (timezone_t tz) -{ - char *env_tz = getenv_TZ (); - if (env_tz - ? tz->tz_is_set && strcmp (tz->abbrs, env_tz) == 0 - : !tz->tz_is_set) - return local_tz; - else - { - timezone_t old_tz = tzalloc (env_tz); - if (!old_tz) - return old_tz; - if (! change_env (tz)) - { - int saved_errno = errno; - tzfree (old_tz); - errno = saved_errno; - return NULL; - } - return old_tz; - } -} - -/* Restore an old setting returned by set_tz. It must not be null. - Return true (preserving errno) if successful, false (setting errno) - otherwise. */ -static bool -revert_tz (timezone_t tz) -{ - if (tz == local_tz) - return true; - else - { - int saved_errno = errno; - bool ok = change_env (tz); - if (!ok) - saved_errno = errno; - tzfree (tz); - errno = saved_errno; - return ok; - } -} - -/* Use time zone TZ to compute localtime_r (T, TM). */ -struct tm * -localtime_rz (timezone_t tz, time_t const *t, struct tm *tm) -{ - if (!tz) - return gmtime_r (t, tm); - else - { - timezone_t old_tz = set_tz (tz); - if (old_tz) - { - bool abbr_saved = localtime_r (t, tm) && save_abbr (tz, tm); - if (revert_tz (old_tz) && abbr_saved) - return tm; - } - return NULL; - } -} - -/* Use time zone TZ to compute mktime (TM). */ -time_t -mktime_z (timezone_t tz, struct tm *tm) -{ - if (!tz) - return timegm (tm); - else - { - timezone_t old_tz = set_tz (tz); - if (old_tz) - { - time_t t = mktime (tm); -#if HAVE_TM_ZONE || HAVE_TZNAME - time_t badtime = -1; - struct tm tm_1; - if ((t != badtime - || (localtime_r (&t, &tm_1) && equal_tm (tm, &tm_1))) - && !save_abbr (tz, tm)) - t = badtime; -#endif - if (revert_tz (old_tz)) - return t; - } - return -1; - } -} |