* Portions Copyright (c) 1996-2003, PostgreSQL Global Development Group
*
* IDENTIFICATION
- * $PostgreSQL: pgsql/src/timezone/pgtz.c,v 1.20 2004/07/30 17:31:24 tgl Exp $
+ * $PostgreSQL: pgsql/src/timezone/pgtz.c,v 1.21 2004/07/31 19:12:15 tgl Exp $
*
*-------------------------------------------------------------------------
*/
#include "utils/guc.h"
-#define T_DAY ((time_t) (60*60*24))
-#define T_WEEK ((time_t) (60*60*24*7))
-#define T_MONTH ((time_t) (60*60*24*31))
-
-#define MAX_TEST_TIMES (52*40) /* 40 years, or 1964..2004 */
-
-struct tztry
-{
- int n_test_times;
- time_t test_times[MAX_TEST_TIMES];
-};
-
static char tzdir[MAXPGPATH];
static int done_tzdir = 0;
-static void scan_available_timezones(char *tzdir, char *tzdirsub,
- struct tztry *tt,
- int *bestscore, char *bestzonename);
+static const char *identify_system_timezone(void);
/*
return tzdir;
}
+
+/*
+ * The following block of code attempts to determine which timezone in our
+ * timezone database is the best match for the active system timezone.
+ *
+ * On most systems, we rely on trying to match the observable behavior of
+ * the C library's localtime() function. The database zone that matches
+ * furthest into the past is the one to use. Often there will be several
+ * zones with identical rankings (since the zic database assigns multiple
+ * names to many zones). We break ties arbitrarily by preferring shorter,
+ * then alphabetically earlier zone names.
+ *
+ * Win32's native knowledge about timezones appears to be too incomplete
+ * and too different from the zic database for the above matching strategy
+ * to be of any use. But there is just a limited number of timezones
+ * available, so we can rely on a handmade mapping table instead.
+ */
+
+#ifndef WIN32
+
+#define T_DAY ((time_t) (60*60*24))
+#define T_WEEK ((time_t) (60*60*24*7))
+#define T_MONTH ((time_t) (60*60*24*31))
+
+#define MAX_TEST_TIMES (52*100) /* 100 years, or 1904..2004 */
+
+struct tztry
+{
+ int n_test_times;
+ time_t test_times[MAX_TEST_TIMES];
+};
+
+static void scan_available_timezones(char *tzdir, char *tzdirsub,
+ struct tztry *tt,
+ int *bestscore, char *bestzonename);
+
+
/*
* Get GMT offset from a system struct tm
*/
#endif
}
-/*
- * Grotty kluge for win32 ... do we really need this?
- */
-#ifdef WIN32
-#define TZABBREV(tz) win32_get_timezone_abbrev(tz)
-
-static char *
-win32_get_timezone_abbrev(const char *tz)
-{
- static char w32tzabbr[TZ_STRLEN_MAX + 1];
- int l = 0;
- const char *c;
-
- for (c = tz; *c; c++)
- {
- if (isupper((unsigned char) *c))
- w32tzabbr[l++] = *c;
- }
- w32tzabbr[l] = '\0';
- return w32tzabbr;
-}
-
-#else
-#define TZABBREV(tz) (tz)
-#endif
-
/*
* Convenience subroutine to convert y/m/d to time_t (NOT pg_time_t)
*/
return -1; /* probably shouldn't happen */
memset(cbuf, 0, sizeof(cbuf));
strftime(cbuf, sizeof(cbuf) - 1, "%Z", systm); /* zone abbr */
- if (strcmp(TZABBREV(cbuf), pgtm->tm_zone) != 0)
+ if (strcmp(cbuf, pgtm->tm_zone) != 0)
{
elog(DEBUG4, "TZ \"%s\" scores %d: at %ld \"%s\" versus \"%s\"",
tzname, i, (long) pgtt,
* the system TZ environment setting (if indeed there is one) matches our
* terminology, so we ignore it and just look at what localtime() returns.
*/
-static char *
+static const char *
identify_system_timezone(void)
{
static char resultbuf[TZ_STRLEN_MAX + 1];
* matches the system zone. We first probe January and July of 2004;
* this serves to quickly eliminate the vast majority of the TZ database
* entries. If those dates match, we probe every week from 2004 backwards
- * to late 1964. (Weekly resolution is good enough to identify DST
+ * to late 1904. (Weekly resolution is good enough to identify DST
* transition rules, since everybody switches on Sundays.) The further
* back the zone matches, the better we score it. This may seem like
* a rather random way of doing things, but experience has shown that
/* Search for the best-matching timezone file */
strcpy(tmptzdir, pg_TZDIR());
- bestscore = 0;
+ bestscore = -1;
+ resultbuf[0] = '\0';
scan_available_timezones(tmptzdir, tmptzdir + strlen(tmptzdir) + 1,
&tt,
&bestscore, resultbuf);
/* found STD zone */
memset(cbuf, 0, sizeof(cbuf));
strftime(cbuf, sizeof(cbuf) - 1, "%Z", tm); /* zone abbr */
- strcpy(std_zone_name, TZABBREV(cbuf));
+ strcpy(std_zone_name, cbuf);
std_ofs = get_timezone_offset(tm);
}
if (tm->tm_isdst > 0 && dst_zone_name[0] == '\0')
/* found DST zone */
memset(cbuf, 0, sizeof(cbuf));
strftime(cbuf, sizeof(cbuf) - 1, "%Z", tm); /* zone abbr */
- strcpy(dst_zone_name, TZABBREV(cbuf));
+ strcpy(dst_zone_name, cbuf);
}
/* Done if found both */
if (std_zone_name[0] && dst_zone_name[0])
direntry = readdir(dirdesc);
if (!direntry)
{
-#ifdef WIN32
- /* This fix is in mingw cvs (runtime/mingwex/dirent.c rev 1.4),
- * but not in released version
- */
- if (GetLastError() == ERROR_NO_MORE_FILES)
- errno = 0;
-#endif
if (errno)
ereport(LOG,
(errcode_for_file_access(),
*bestscore = score;
StrNCpy(bestzonename, tzdirsub, TZ_STRLEN_MAX + 1);
}
+ else if (score == *bestscore)
+ {
+ /* Consider how to break a tie */
+ if (strlen(tzdirsub) < strlen(bestzonename) ||
+ (strlen(tzdirsub) == strlen(bestzonename) &&
+ strcmp(tzdirsub, bestzonename) < 0))
+ StrNCpy(bestzonename, tzdirsub, TZ_STRLEN_MAX + 1);
+ }
}
}
tzdir[tzdir_orig_len] = '\0';
}
+#else /* WIN32 */
+
+static const struct {
+ const char *stdname; /* Windows name of standard timezone */
+ const char *dstname; /* Windows name of daylight timezone */
+ const char *pgtzname; /* Name of pgsql timezone to map to */
+} win32_tzmap[] = {
+ /*
+ * This list was built from the contents of the registry at
+ * HKEY_LOCAL_MACHINE\SOFTWARE\Microsoft\Windows NT\CurrentVersion\Time Zones
+ * on Windows XP Professional SP1
+ *
+ * The zones have been matched to zic timezones by looking at the cities
+ * listed in the win32 display name (in the comment here) in most cases.
+ */
+ {"Afghanistan Standard Time", "Afghanistan Daylight Time",
+ "Asia/Kabul"}, /* (GMT+04:30) Kabul */
+ {"Alaskan Standard Time", "Alaskan Daylight Time",
+ "US/Alaska"}, /* (GMT-09:00) Alaska */
+ {"Arab Standard Time", "Arab Daylight Time",
+ "Asia/Kuwait"}, /* (GMT+03:00) Kuwait, Riyadh */
+ {"Arabian Standard Time", "Arabian Daylight Time",
+ "Asia/Muscat"}, /* (GMT+04:00) Abu Dhabi, Muscat */
+ {"Arabic Standard Time", "Arabic Daylight Time",
+ "Asia/Baghdad"}, /* (GMT+03:00) Baghdad */
+ {"Atlantic Standard Time", "Atlantic Daylight Time",
+ "Canada/Atlantic"}, /* (GMT-04:00) Atlantic Time (Canada) */
+ {"AUS Central Standard Time", "AUS Central Daylight Time",
+ "Australia/Darwin"}, /* (GMT+09:30) Darwin */
+ {"AUS Eastern Standard Time", "AUS Eastern Daylight Time",
+ "Australia/Canberra"}, /* (GMT+10:00) Canberra, Melbourne, Sydney */
+ {"Azores Standard Time", "Azores Daylight Time",
+ "Atlantic/Azores"}, /* (GMT-01:00) Azores */
+ {"Canada Central Standard Time", "Canada Central Daylight Time",
+ "Canada/Saskatchewan"}, /* (GMT-06:00) Saskatchewan */
+ {"Cape Verde Standard Time", "Cape Verde Daylight Time",
+ "Atlantic/Cape_Verde"}, /* (GMT-01:00) Cape Verde Is. */
+ {"Caucasus Standard Time", "Caucasus Daylight Time",
+ "Asia/Baku"}, /* (GMT+04:00) Baku, Tbilisi, Yerevan */
+ {"Cen. Australia Standard Time", "Cen. Australia Daylight Time",
+ "Australia/Adelaide"}, /* (GMT+09:30) Adelaide */
+ {"Central America Standard Time", "Central America Daylight Time",
+ "CST6CDT"}, /* (GMT-06:00) Central America */
+ {"Central Asia Standard Time", "Central Asia Daylight Time",
+ "Asia/Dhaka"}, /* (GMT+06:00) Astana, Dhaka */
+ {"Central Europe Standard Time", "Central Europe Daylight Time",
+ "Europe/Belgrade"}, /* (GMT+01:00) Belgrade, Bratislava, Budapest, Ljubljana, Prague */
+ {"Central European Standard Time", "Central European Daylight Time",
+ "Europe/Sarajevo"}, /* (GMT+01:00) Sarajevo, Skopje, Warsaw, Zagreb */
+ {"Central Pacific Standard Time", "Central Pacific Daylight Time",
+ "Pacific/Noumea"}, /* (GMT+11:00) Magadan, Solomon Is., New Caledonia */
+ {"Central Standard Time", "Central Daylight Time",
+ "US/Central"}, /* (GMT-06:00) Central Time (US & Canada) */
+ {"China Standard Time", "China Daylight Time",
+ "Asia/Hong_Kong"}, /* (GMT+08:00) Beijing, Chongqing, Hong Kong, Urumqi */
+ {"Dateline Standard Time", "Dateline Daylight Time",
+ "Etc/GMT+12"}, /* (GMT-12:00) International Date Line West */
+ {"E. Africa Standard Time", "E. Africa Daylight Time",
+ "Africa/Nairobi"}, /* (GMT+03:00) Nairobi */
+ {"E. Australia Standard Time", "E. Australia Daylight Time",
+ "Australia/Brisbane"}, /* (GMT+10:00) Brisbane */
+ {"E. Europe Standard Time", "E. Europe Daylight Time",
+ "Europe/Bucharest"}, /* (GMT+02:00) Bucharest */
+ {"E. South America Standard Time", "E. South America Daylight Time",
+ "America/Araguaina"}, /* (GMT-03:00) Brasilia */
+ {"Eastern Standard Time", "Eastern Daylight Time",
+ "US/Eastern"}, /* (GMT-05:00) Eastern Time (US & Canada) */
+ {"Egypt Standard Time", "Egypt Daylight Time",
+ "Africa/Cairo"}, /* (GMT+02:00) Cairo */
+ {"Ekaterinburg Standard Time", "Ekaterinburg Daylight Time",
+ "Asia/Yekaterinburg"}, /* (GMT+05:00) Ekaterinburg */
+ {"Fiji Standard Time", "Fiji Daylight Time",
+ "Pacific/Fiji"}, /* (GMT+12:00) Fiji, Kamchatka, Marshall Is. */
+ {"FLE Standard Time", "FLE Daylight Time",
+ "Europe/Helsinki"}, /* (GMT+02:00) Helsinki, Kyiv, Riga, Sofia, Tallinn, Vilnius */
+ {"GMT Standard Time", "GMT Daylight Time",
+ "Europe/Dublin"}, /* (GMT) Greenwich Mean Time : Dublin, Edinburgh, Lisbon, London */
+ {"Greenland Standard Time", "Greenland Daylight Time",
+ "America/Godthab"}, /* (GMT-03:00) Greenland */
+ {"Greenwich Standard Time", "Greenwich Daylight Time",
+ "Africa/Casablanca"}, /* (GMT) Casablanca, Monrovia */
+ {"GTB Standard Time", "GTB Daylight Time",
+ "Europe/Athens"}, /* (GMT+02:00) Athens, Istanbul, Minsk */
+ {"Hawaiian Standard Time", "Hawaiian Daylight Time",
+ "US/Hawaii"}, /* (GMT-10:00) Hawaii */
+ {"India Standard Time", "India Daylight Time",
+ "Asia/Calcutta"}, /* (GMT+05:30) Chennai, Kolkata, Mumbai, New Delhi */
+ {"Iran Standard Time", "Iran Daylight Time",
+ "Asia/Tehran"}, /* (GMT+03:30) Tehran */
+ {"Jerusalem Standard Time", "Jerusalem Daylight Time",
+ "Asia/Jerusalem"}, /* (GMT+02:00) Jerusalem */
+ {"Korea Standard Time", "Korea Daylight Time",
+ "Asia/Seoul"}, /* (GMT+09:00) Seoul */
+ {"Mexico Standard Time", "Mexico Daylight Time",
+ "America/Mexico_City"}, /* (GMT-06:00) Guadalajara, Mexico City, Monterrey */
+ {"Mexico Standard Time", "Mexico Daylight Time",
+ "America/La_Paz"}, /* (GMT-07:00) Chihuahua, La Paz, Mazatlan */
+ {"Mid-Atlantic Standard Time", "Mid-Atlantic Daylight Time",
+ "Atlantic/South_Georgia"}, /* (GMT-02:00) Mid-Atlantic */
+ {"Mountain Standard Time", "Mountain Daylight Time",
+ "US/Mountain"}, /* (GMT-07:00) Mountain Time (US & Canada) */
+ {"Myanmar Standard Time", "Myanmar Daylight Time",
+ "Asia/Rangoon"}, /* (GMT+06:30) Rangoon */
+ {"N. Central Asia Standard Time", "N. Central Asia Daylight Time",
+ "Asia/Almaty"}, /* (GMT+06:00) Almaty, Novosibirsk */
+ {"Nepal Standard Time", "Nepal Daylight Time",
+ "Asia/Katmandu"}, /* (GMT+05:45) Kathmandu */
+ {"New Zealand Standard Time", "New Zealand Daylight Time",
+ "Pacific/Auckland"}, /* (GMT+12:00) Auckland, Wellington */
+ {"Newfoundland Standard Time", "Newfoundland Daylight Time",
+ "Canada/Newfoundland"}, /* (GMT-03:30) Newfoundland */
+ {"North Asia East Standard Time", "North Asia East Daylight Time",
+ "Asia/Irkutsk"}, /* (GMT+08:00) Irkutsk, Ulaan Bataar */
+ {"North Asia Standard Time", "North Asia Daylight Time",
+ "Asia/Krasnoyarsk"}, /* (GMT+07:00) Krasnoyarsk */
+ {"Pacific SA Standard Time", "Pacific SA Daylight Time",
+ "America/Santiago"}, /* (GMT-04:00) Santiago */
+ {"Pacific Standard Time", "Pacific Daylight Time",
+ "US/Pacific"}, /* (GMT-08:00) Pacific Time (US & Canada); Tijuana */
+ {"Romance Standard Time", "Romance Daylight Time",
+ "Europe/Brussels"}, /* (GMT+01:00) Brussels, Copenhagen, Madrid, Paris */
+ {"Russian Standard Time", "Russian Daylight Time",
+ "Europe/Moscow"}, /* (GMT+03:00) Moscow, St. Petersburg, Volgograd */
+ {"SA Eastern Standard Time", "SA Eastern Daylight Time",
+ "America/Buenos_Aires"}, /* (GMT-03:00) Buenos Aires, Georgetown */
+ {"SA Pacific Standard Time", "SA Pacific Daylight Time",
+ "America/Bogota"}, /* (GMT-05:00) Bogota, Lima, Quito */
+ {"SA Western Standard Time", "SA Western Daylight Time",
+ "America/Caracas"}, /* (GMT-04:00) Caracas, La Paz */
+ {"Samoa Standard Time", "Samoa Daylight Time",
+ "Pacific/Midway"}, /* (GMT-11:00) Midway Island, Samoa */
+ {"SE Asia Standard Time", "SE Asia Daylight Time",
+ "Asia/Bangkok"}, /* (GMT+07:00) Bangkok, Hanoi, Jakarta */
+ {"Malay Peninsula Standard Time", "Malay Peninsula Daylight Time",
+ "Asia/Kuala_Lumpur"}, /* (GMT+08:00) Kuala Lumpur, Singapore */
+ {"South Africa Standard Time", "South Africa Daylight Time",
+ "Africa/Harare"}, /* (GMT+02:00) Harare, Pretoria */
+ {"Sri Lanka Standard Time", "Sri Lanka Daylight Time",
+ "Asia/Colombo"}, /* (GMT+06:00) Sri Jayawardenepura */
+ {"Taipei Standard Time", "Taipei Daylight Time",
+ "Asia/Taipei"}, /* (GMT+08:00) Taipei */
+ {"Tasmania Standard Time", "Tasmania Daylight Time",
+ "Australia/Hobart"}, /* (GMT+10:00) Hobart */
+ {"Tokyo Standard Time", "Tokyo Daylight Time",
+ "Asia/Tokyo"}, /* (GMT+09:00) Osaka, Sapporo, Tokyo */
+ {"Tonga Standard Time", "Tonga Daylight Time",
+ "Pacific/Tongatapu"}, /* (GMT+13:00) Nuku'alofa */
+ {"US Eastern Standard Time", "US Eastern Daylight Time",
+ "US/Eastern"}, /* (GMT-05:00) Indiana (East) */
+ {"US Mountain Standard Time", "US Mountain Daylight Time",
+ "US/Arizona"}, /* (GMT-07:00) Arizona */
+ {"Vladivostok Standard Time", "Vladivostok Daylight Time",
+ "Asia/Vladivostok"}, /* (GMT+10:00) Vladivostok */
+ {"W. Australia Standard Time", "W. Australia Daylight Time",
+ "Australia/Perth"}, /* (GMT+08:00) Perth */
+/* {"W. Central Africa Standard Time", "W. Central Africa Daylight Time",
+ ""}, Could not find a match for this one. Excluded for now. */ /* (GMT+01:00) West Central Africa */
+ {"W. Europe Standard Time", "W. Europe Daylight Time",
+ "CET"}, /* (GMT+01:00) Amsterdam, Berlin, Bern, Rome, Stockholm, Vienna */
+ {"West Asia Standard Time", "West Asia Daylight Time",
+ "Asia/Karachi"}, /* (GMT+05:00) Islamabad, Karachi, Tashkent */
+ {"West Pacific Standard Time", "West Pacific Daylight Time",
+ "Pacific/Guam"}, /* (GMT+10:00) Guam, Port Moresby */
+ {"Yakutsk Standard Time", "Yakutsk Daylight Time",
+ "Asia/Yakutsk"}, /* (GMT+09:00) Yakutsk */
+ {NULL, NULL, NULL}
+};
+
+static const char *
+identify_system_timezone(void)
+{
+ int i;
+ char tzname[128];
+ time_t t = time(NULL);
+ struct tm *tm = localtime(&t);
+
+ if (!tm)
+ {
+ ereport(WARNING,
+ (errmsg_internal("could not determine current date/time: localtime failed")));
+ return NULL;
+ }
+
+ memset(tzname, 0, sizeof(tzname));
+ strftime(tzname, sizeof(tzname)-1, "%Z", tm);
+
+ for (i=0; win32_tzmap[i].stdname != NULL; i++)
+ {
+ if (strcmp(tzname, win32_tzmap[i].stdname) == 0 ||
+ strcmp(tzname, win32_tzmap[i].dstname) == 0)
+ {
+ elog(DEBUG4, "TZ \"%s\" matches Windows timezone \"%s\"",
+ win32_tzmap[i].pgtzname, tzname);
+ return win32_tzmap[i].pgtzname;
+ }
+ }
+
+ ereport(WARNING,
+ (errmsg("could not find a match for Windows timezone \"%s\"",
+ tzname)));
+ return NULL;
+}
+
+#endif /* WIN32 */
+
/*
* Check whether timezone is acceptable.
const char *
select_default_timezone(void)
{
- char *def_tz;
+ const char *def_tz;
def_tz = getenv("TZ");
if (def_tz && pg_tzset(def_tz) && tz_acceptable())
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