diff options
Diffstat (limited to 'src/timezone/pgtz.c')
| -rw-r--r-- | src/timezone/pgtz.c | 127 |
1 files changed, 117 insertions, 10 deletions
diff --git a/src/timezone/pgtz.c b/src/timezone/pgtz.c index 599aaac4efc..f228ed5bacf 100644 --- a/src/timezone/pgtz.c +++ b/src/timezone/pgtz.c @@ -6,7 +6,7 @@ * Portions Copyright (c) 1996-2005, PostgreSQL Global Development Group * * IDENTIFICATION - * $PostgreSQL: pgsql/src/timezone/pgtz.c,v 1.29 2004/12/31 22:03:59 pgsql Exp $ + * $PostgreSQL: pgsql/src/timezone/pgtz.c,v 1.30 2005/04/19 03:13:59 momjian Exp $ * *------------------------------------------------------------------------- */ @@ -26,12 +26,18 @@ #include "utils/datetime.h" #include "utils/elog.h" #include "utils/guc.h" +#include "utils/hsearch.h" + +/* Current global timezone */ +pg_tz *global_timezone = NULL; static char tzdir[MAXPGPATH]; static int done_tzdir = 0; static const char *identify_system_timezone(void); +static const char *select_default_timezone(void); +static bool set_global_timezone(const char *tzname); /* @@ -156,12 +162,14 @@ score_timezone(const char *tzname, struct tztry * tt) struct tm *systm; struct pg_tm *pgtm; char cbuf[TZ_STRLEN_MAX + 1]; + pg_tz *tz; - if (!pg_tzset(tzname)) + tz = pg_tzset(tzname); + if (!tz) return -1; /* can't handle the TZ name at all */ /* Reject if leap seconds involved */ - if (!tz_acceptable()) + if (!tz_acceptable(tz)) { elog(DEBUG4, "Reject TZ \"%s\": uses leap seconds", tzname); return -1; @@ -171,7 +179,7 @@ score_timezone(const char *tzname, struct tztry * tt) for (i = 0; i < tt->n_test_times; i++) { pgtt = (pg_time_t) (tt->test_times[i]); - pgtm = pg_localtime(&pgtt); + pgtm = pg_localtime(&pgtt, tz); if (!pgtm) return -1; /* probably shouldn't happen */ systm = localtime(&(tt->test_times[i])); @@ -957,6 +965,82 @@ identify_system_timezone(void) #endif /* WIN32 */ + +/* + * We keep loaded timezones in a hashtable so we don't have to + * load and parse the TZ definition file every time it is selected. + */ +static HTAB *timezone_cache = NULL; +static bool +init_timezone_hashtable(void) +{ + HASHCTL hash_ctl; + + MemSet(&hash_ctl, 0, sizeof(hash_ctl)); + + hash_ctl.keysize = TZ_STRLEN_MAX; + hash_ctl.entrysize = sizeof(pg_tz); + + timezone_cache = hash_create("Timezones", + 31, + &hash_ctl, + HASH_ELEM); + if (!timezone_cache) + return false; + + return true; +} + +/* + * Load a timezone from file or from cache. + * Does not verify that the timezone is acceptable! + */ +struct pg_tz * +pg_tzset(const char *name) +{ + pg_tz *tzp; + pg_tz tz; + + if (strlen(name) >= TZ_STRLEN_MAX) + return NULL; /* not going to fit */ + + if (!timezone_cache) + if (!init_timezone_hashtable()) + return NULL; + + tzp = (pg_tz *)hash_search(timezone_cache, + name, + HASH_FIND, + NULL); + if (tzp) + /* Timezone found in cache, nothing more to do */ + return tzp; + + if (tzload(name, &tz.state) != 0) + { + if (name[0] == ':' || tzparse(name, &tz.state, FALSE) != 0) + /* Unknown timezone. Fail our call instead of loading GMT! */ + return NULL; + } + + strcpy(tz.TZname, name); + + /* Save timezone in the cache */ + tzp = hash_search(timezone_cache, + name, + HASH_ENTER, + NULL); + + if (!tzp) + return NULL; + + strcpy(tzp->TZname, tz.TZname); + memcpy(&tzp->state, &tz.state, sizeof(tz.state)); + + return tzp; +} + + /* * Check whether timezone is acceptable. * @@ -968,7 +1052,7 @@ identify_system_timezone(void) * it can restore the old value of TZ if we don't like the new one. */ bool -tz_acceptable(void) +tz_acceptable(pg_tz *tz) { struct pg_tm *tt; pg_time_t time2000; @@ -979,13 +1063,36 @@ tz_acceptable(void) * any other result has to be due to leap seconds. */ time2000 = (POSTGRES_EPOCH_JDATE - UNIX_EPOCH_JDATE) * 86400; - tt = pg_localtime(&time2000); + tt = pg_localtime(&time2000, tz); if (!tt || tt->tm_sec != 0) return false; return true; } + +/* + * Set the global timezone. Verify that it's acceptable first. + */ +static bool +set_global_timezone(const char *tzname) +{ + pg_tz *tznew; + + if (!tzname || !tzname[0]) + return false; + + tznew = pg_tzset(tzname); + if (!tznew) + return false; + + if (!tz_acceptable(tznew)) + return false; + + global_timezone = tznew; + return true; +} + /* * Identify a suitable default timezone setting based on the environment, * and make it active. @@ -995,20 +1102,20 @@ tz_acceptable(void) * from the behavior of the system timezone library. When all else fails, * fall back to GMT. */ -const char * +static const char * select_default_timezone(void) { const char *def_tz; def_tz = getenv("TZ"); - if (def_tz && pg_tzset(def_tz) && tz_acceptable()) + if (set_global_timezone(def_tz)) return def_tz; def_tz = identify_system_timezone(); - if (def_tz && pg_tzset(def_tz) && tz_acceptable()) + if (set_global_timezone(def_tz)) return def_tz; - if (pg_tzset("GMT") && tz_acceptable()) + if (set_global_timezone("GMT")) return "GMT"; ereport(FATAL, |