Sets the time zone used for timestamps written in the server log.
Unlike <xref linkend="guc-timezone">, this value is cluster-wide,
so that all sessions will report timestamps consistently.
- If not explicitly set, the server initializes this variable to the
- time zone specified by its system environment. See <xref
- linkend="datatype-timezones"> for more information.
+ The built-in default is <literal>GMT</>, but that is typically
+ overridden in <filename>postgresql.conf</>; <application>initdb</>
+ will install a setting there corresponding to its system environment.
+ See <xref linkend="datatype-timezones"> for more information.
This parameter can only be set in the <filename>postgresql.conf</>
file or on the server command line.
</para>
<listitem>
<para>
Sets the time zone for displaying and interpreting time stamps.
- If not explicitly set, the server initializes this variable to the
- time zone specified by its system environment. See <xref
- linkend="datatype-timezones"> for more information.
+ The built-in default is <literal>GMT</>, but that is typically
+ overridden in <filename>postgresql.conf</>; <application>initdb</>
+ will install a setting there corresponding to its system environment.
+ See <xref linkend="datatype-timezones"> for more information.
</para>
</listitem>
</varlistentry>
but continue to be prone to arbitrary changes, particularly with
respect to daylight-savings rules.
<productname>PostgreSQL</productname> uses the widely-used
- <literal>zoneinfo</> time zone database for information about
+ <literal>zoneinfo</> (Olson) time zone database for information about
historical time zone rules. For times in the future, the assumption
is that the latest known rules for a given time zone will
continue to be observed indefinitely far into the future.
The <xref linkend="guc-timezone"> configuration parameter can
be set in the file <filename>postgresql.conf</>, or in any of the
other standard ways described in <xref linkend="runtime-config">.
- There are also several special ways to set it:
+ There are also some special ways to set it:
<itemizedlist>
- <listitem>
- <para>
- If <varname>timezone</> is not specified in
- <filename>postgresql.conf</> or as a server command-line option,
- the server attempts to use the value of the <envar>TZ</envar>
- environment variable as the default time zone. If <envar>TZ</envar>
- is not defined or is not any of the time zone names known to
- <productname>PostgreSQL</productname>, the server attempts to
- determine the operating system's default time zone by checking the
- behavior of the C library function <literal>localtime()</>. The
- default time zone is selected as the closest match among
- <productname>PostgreSQL</productname>'s known time zones.
- (These rules are also used to choose the default value of
- <xref linkend="guc-log-timezone">, if not specified.)
- </para>
- </listitem>
-
<listitem>
<para>
The <acronym>SQL</acronym> command <command>SET TIME ZONE</command>
<listitem>
<para>
Set the time zone to your local time zone (that is, the
- server's default value of <varname>timezone</>; if this
- has not been explicitly set anywhere, it will be the zone that
- the server's operating system defaults to).
+ server's default value of <varname>timezone</>).
</para>
</listitem>
</varlistentry>
{
if (!SelectConfigFiles(userDoption, progname))
proc_exit(1);
- /* If timezone is not set, determine what the OS uses */
- pg_timezone_initialize();
- /* If timezone_abbreviations is not set, select default */
- pg_timezone_abbrev_initialize();
}
/* Validate we have been given a reasonable-looking DataDir */
char *endptr;
double hours;
- if (*newval == NULL)
- {
- /*
- * The boot_val given for TimeZone in guc.c is NULL. When we see this
- * we just do nothing. If this isn't overridden from the config file
- * then pg_timezone_initialize() will eventually select a default
- * value from the environment. This hack has two purposes: to avoid
- * wasting cycles loading values that might soon be overridden from
- * the config file, and to avoid trying to read the timezone files
- * during InitializeGUCOptions(). The latter doesn't work in an
- * EXEC_BACKEND subprocess because my_exec_path hasn't been set yet
- * and so we can't locate PGSHAREDIR.
- */
- Assert(source == PGC_S_DEFAULT);
- return true;
- }
-
/*
* Initialize the "extra" struct that will be passed to assign_timezone.
* We don't want to change any of the three global variables except as
return false;
}
- if (!tz_acceptable(new_tz))
+ if (!pg_tz_acceptable(new_tz))
{
GUC_check_errmsg("time zone \"%s\" appears to use leap seconds",
*newval);
{
timezone_extra *myextra = (timezone_extra *) extra;
- /* Do nothing for the boot_val default of NULL */
- if (!myextra)
- return;
-
session_timezone = myextra->session_timezone;
CTimeZone = myextra->CTimeZone;
HasCTZSet = myextra->HasCTZSet;
{
pg_tz *new_tz;
- if (*newval == NULL)
- {
- /*
- * The boot_val given for log_timezone in guc.c is NULL. When we see
- * this we just do nothing. If this isn't overridden from the config
- * file then pg_timezone_initialize() will eventually select a default
- * value from the environment.
- */
- Assert(source == PGC_S_DEFAULT);
- return true;
- }
-
/*
- * Otherwise assume it is a timezone name, and try to load it.
+ * Assume it is a timezone name, and try to load it.
*/
new_tz = pg_tzset(*newval);
return false;
}
- if (!tz_acceptable(new_tz))
+ if (!pg_tz_acceptable(new_tz))
{
GUC_check_errmsg("time zone \"%s\" appears to use leap seconds",
*newval);
void
assign_log_timezone(const char *newval, void *extra)
{
- /* Do nothing for the boot_val default of NULL */
- if (!extra)
- return;
-
log_timezone = *((pg_tz **) extra);
}
*/
CreateDataDirLockFile(true);
- /*
- * If timezone is not set, determine what the OS uses. (In theory this
- * should be done during GUC initialization, but because it can take as
- * much as several seconds, we delay it until after we've created the
- * postmaster.pid file. This prevents problems with boot scripts that
- * expect the pidfile to appear quickly. Also, we avoid problems with
- * trying to locate the timezone files too early in initialization.)
- */
- pg_timezone_initialize();
-
- /*
- * Likewise, init timezone_abbreviations if not already set.
- */
- pg_timezone_abbrev_initialize();
-
/*
* Initialize SSL library, if specified.
*/
{
if (!SelectConfigFiles(userDoption, progname))
proc_exit(1);
- /* If timezone is not set, determine what the OS uses */
- pg_timezone_initialize();
- /* If timezone_abbreviations is not set, select default */
- pg_timezone_abbrev_initialize();
}
/*
{
struct timeval tv;
pg_time_t stamp_time;
- pg_tz *tz;
char msbuf[8];
gettimeofday(&tv, NULL);
stamp_time = (pg_time_t) tv.tv_sec;
/*
- * Normally we print log timestamps in log_timezone, but during startup we
- * could get here before that's set. If so, fall back to gmt_timezone
- * (which guc.c ensures is set up before Log_line_prefix can become
- * nonempty).
+ * Note: we expect that guc.c will ensure that log_timezone is set up
+ * (at least with a minimal GMT value) before Log_line_prefix can become
+ * nonempty or CSV mode can be selected.
*/
- tz = log_timezone ? log_timezone : gmt_timezone;
-
pg_strftime(formatted_log_time, FORMATTED_TS_LEN,
/* leave room for milliseconds... */
"%Y-%m-%d %H:%M:%S %Z",
- pg_localtime(&stamp_time, tz));
+ pg_localtime(&stamp_time, log_timezone));
/* 'paste' milliseconds into place... */
sprintf(msbuf, ".%03d", (int) (tv.tv_usec / 1000));
setup_formatted_start_time(void)
{
pg_time_t stamp_time = (pg_time_t) MyStartTime;
- pg_tz *tz;
/*
- * Normally we print log timestamps in log_timezone, but during startup we
- * could get here before that's set. If so, fall back to gmt_timezone
- * (which guc.c ensures is set up before Log_line_prefix can become
- * nonempty).
+ * Note: we expect that guc.c will ensure that log_timezone is set up
+ * (at least with a minimal GMT value) before Log_line_prefix can become
+ * nonempty or CSV mode can be selected.
*/
- tz = log_timezone ? log_timezone : gmt_timezone;
-
pg_strftime(formatted_start_time, FORMATTED_TS_LEN,
"%Y-%m-%d %H:%M:%S %Z",
- pg_localtime(&stamp_time, tz));
+ pg_localtime(&stamp_time, log_timezone));
}
/*
case 't':
{
pg_time_t stamp_time = (pg_time_t) time(NULL);
- pg_tz *tz;
char strfbuf[128];
- tz = log_timezone ? log_timezone : gmt_timezone;
-
pg_strftime(strfbuf, sizeof(strfbuf),
"%Y-%m-%d %H:%M:%S %Z",
- pg_localtime(&stamp_time, tz));
+ pg_localtime(&stamp_time, log_timezone));
appendStringInfoString(buf, strfbuf);
}
break;
if (context == PGC_SIGHUP)
{
InitializeGUCOptionsFromEnvironment();
- pg_timezone_initialize();
pg_timezone_abbrev_initialize();
/* this selects SQL_ASCII in processes not connected to a database */
SetConfigOption("client_encoding", GetDatabaseEncodingName(),
static bool check_canonical_path(char **newval, void **extra, GucSource source);
static bool check_timezone_abbreviations(char **newval, void **extra, GucSource source);
static void assign_timezone_abbreviations(const char *newval, void *extra);
+static void pg_timezone_abbrev_initialize(void);
static const char *show_archive_command(void);
static void assign_tcp_keepalives_idle(int newval, void *extra);
static void assign_tcp_keepalives_interval(int newval, void *extra);
NULL
},
&log_timezone_string,
- NULL,
+ "GMT",
check_log_timezone, assign_log_timezone, show_log_timezone
},
GUC_REPORT
},
&timezone_string,
- NULL,
+ "GMT",
check_timezone, assign_timezone, show_timezone
},
{
* Before log_line_prefix could possibly receive a nonempty setting, make
* sure that timezone processing is minimally alive (see elog.c).
*/
- pg_timezone_pre_initialize();
+ pg_timezone_initialize();
/*
* Build sorted array of all GUC variables.
*/
SetConfigOption("data_directory", DataDir, PGC_POSTMASTER, PGC_S_OVERRIDE);
+ /*
+ * If timezone_abbreviations wasn't set in the configuration file, install
+ * the default value. We do it this way because we can't safely install
+ * a "real" value until my_exec_path is set, which may not have happened
+ * when InitializeGUCOptions runs, so the bootstrap default value cannot
+ * be the real desired default.
+ */
+ pg_timezone_abbrev_initialize();
+
/*
* Figure out where pg_hba.conf is, and make sure the path is absolute.
*/
* This is called after initial loading of postgresql.conf. If no
* timezone_abbreviations setting was found therein, select default.
* If a non-default value is already installed, nothing will happen.
+ *
+ * This can also be called from ProcessConfigFile to establish the default
+ * value after a postgresql.conf entry for it is removed.
*/
-void
+static void
pg_timezone_abbrev_initialize(void)
{
SetConfigOption("timezone_abbreviations", "Default",
#log_temp_files = -1 # log temporary files equal or larger
# than the specified size in kilobytes;
# -1 disables, 0 logs all temp files
-#log_timezone = '(defaults to server environment setting)'
+#log_timezone = 'GMT'
#------------------------------------------------------------------------------
#datestyle = 'iso, mdy'
#intervalstyle = 'postgres'
-#timezone = '(defaults to server environment setting)'
+#timezone = 'GMT'
#timezone_abbreviations = 'Default' # Select the set of available time zone
# abbreviations. Currently, there are
# Default
/encnames.c
/pqsignal.c
+/localtime.c
/initdb
top_builddir = ../../..
include $(top_builddir)/src/Makefile.global
-override CPPFLAGS := -DFRONTEND -I$(libpq_srcdir) $(CPPFLAGS)
+override CPPFLAGS := -DFRONTEND -I$(libpq_srcdir) -I$(top_srcdir)/src/timezone $(CPPFLAGS)
-OBJS= initdb.o encnames.o pqsignal.o $(WIN32RES)
+OBJS= initdb.o findtimezone.o localtime.o encnames.o pqsignal.o $(WIN32RES)
all: initdb
pqsignal.c: % : $(top_srcdir)/src/interfaces/libpq/%
rm -f $@ && $(LN_S) $< .
+# Likewise, pull in localtime.c from src/timezones
+
+localtime.c: % : $(top_srcdir)/src/timezone/%
+ rm -f $@ && $(LN_S) $< .
+
install: all installdirs
$(INSTALL_PROGRAM) initdb$(X) '$(DESTDIR)$(bindir)/initdb$(X)'
rm -f '$(DESTDIR)$(bindir)/initdb$(X)'
clean distclean maintainer-clean:
- rm -f initdb$(X) $(OBJS) encnames.c pqsignal.c
+ rm -f initdb$(X) $(OBJS) encnames.c pqsignal.c localtime.c
# ensure that changes in datadir propagate into object file
--- /dev/null
+/*-------------------------------------------------------------------------
+ *
+ * findtimezone.c
+ * Functions for determining the default timezone to use.
+ *
+ * Portions Copyright (c) 1996-2011, PostgreSQL Global Development Group
+ *
+ * IDENTIFICATION
+ * src/bin/initdb/findtimezone.c
+ *
+ *-------------------------------------------------------------------------
+ */
+#include "postgres_fe.h"
+
+#include <fcntl.h>
+#include <sys/stat.h>
+#include <time.h>
+
+#include "pgtz.h"
+
+/* Ideally this would be in a .h file, but it hardly seems worth the trouble */
+extern const char *select_default_timezone(const char *share_path);
+
+
+#ifndef SYSTEMTZDIR
+static char tzdirpath[MAXPGPATH];
+#endif
+
+
+/*
+ * Return full pathname of timezone data directory
+ *
+ * In this file, tzdirpath is assumed to be set up by select_default_timezone.
+ */
+static const char *
+pg_TZDIR(void)
+{
+#ifndef SYSTEMTZDIR
+ /* normal case: timezone stuff is under our share dir */
+ return tzdirpath;
+#else
+ /* we're configured to use system's timezone database */
+ return SYSTEMTZDIR;
+#endif
+}
+
+
+/*
+ * Given a timezone name, open() the timezone data file. Return the
+ * file descriptor if successful, -1 if not.
+ *
+ * This is simpler than the backend function of the same name because
+ * we assume that the input string has the correct case already, so there
+ * is no need for case-folding. (This is obviously true if we got the file
+ * name from the filesystem to start with. The only other place it can come
+ * from is the environment variable TZ, and there seems no need to allow
+ * case variation in that; other programs aren't likely to.)
+ *
+ * If "canonname" is not NULL, then on success the canonical spelling of the
+ * given name is stored there (the buffer must be > TZ_STRLEN_MAX bytes!).
+ * This is redundant but kept for compatibility with the backend code.
+ */
+int
+pg_open_tzfile(const char *name, char *canonname)
+{
+ char fullname[MAXPGPATH];
+
+ if (canonname)
+ strlcpy(canonname, name, TZ_STRLEN_MAX + 1);
+
+ strcpy(fullname, pg_TZDIR());
+ if (strlen(fullname) + 1 + strlen(name) >= MAXPGPATH)
+ return -1; /* not gonna fit */
+ strcat(fullname, "/");
+ strcat(fullname, name);
+
+ return open(fullname, O_RDONLY | PG_BINARY, 0);
+}
+
+
+
+/*
+ * Load a timezone definition.
+ * Does not verify that the timezone is acceptable!
+ *
+ * This corresponds to the backend's pg_tzset(), except that we only support
+ * one loaded timezone at a time.
+ */
+static pg_tz *
+pg_load_tz(const char *name)
+{
+ static pg_tz tz;
+
+ if (strlen(name) > TZ_STRLEN_MAX)
+ return NULL; /* not going to fit */
+
+ /*
+ * "GMT" is always sent to tzparse(); see comments for pg_tzset().
+ */
+ if (strcmp(name, "GMT") == 0)
+ {
+ if (tzparse(name, &tz.state, TRUE) != 0)
+ {
+ /* This really, really should not happen ... */
+ return NULL;
+ }
+ }
+ else if (tzload(name, NULL, &tz.state, TRUE) != 0)
+ {
+ if (name[0] == ':' || tzparse(name, &tz.state, FALSE) != 0)
+ {
+ return NULL; /* unknown timezone */
+ }
+ }
+
+ strcpy(tz.TZname, name);
+
+ return &tz;
+}
+
+
+/*
+ * 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 Olson 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 Olson 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 */
+
+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
+ */
+static int
+get_timezone_offset(struct tm * tm)
+{
+#if defined(HAVE_STRUCT_TM_TM_ZONE)
+ return tm->tm_gmtoff;
+#elif defined(HAVE_INT_TIMEZONE)
+ return -TIMEZONE_GLOBAL;
+#else
+#error No way to determine TZ? Can this happen?
+#endif
+}
+
+/*
+ * Convenience subroutine to convert y/m/d to time_t (NOT pg_time_t)
+ */
+static time_t
+build_time_t(int year, int month, int day)
+{
+ struct tm tm;
+
+ memset(&tm, 0, sizeof(tm));
+ tm.tm_mday = day;
+ tm.tm_mon = month - 1;
+ tm.tm_year = year - 1900;
+
+ return mktime(&tm);
+}
+
+/*
+ * Does a system tm value match one we computed ourselves?
+ */
+static bool
+compare_tm(struct tm * s, struct pg_tm * p)
+{
+ if (s->tm_sec != p->tm_sec ||
+ s->tm_min != p->tm_min ||
+ s->tm_hour != p->tm_hour ||
+ s->tm_mday != p->tm_mday ||
+ s->tm_mon != p->tm_mon ||
+ s->tm_year != p->tm_year ||
+ s->tm_wday != p->tm_wday ||
+ s->tm_yday != p->tm_yday ||
+ s->tm_isdst != p->tm_isdst)
+ return false;
+ return true;
+}
+
+/*
+ * See how well a specific timezone setting matches the system behavior
+ *
+ * We score a timezone setting according to the number of test times it
+ * matches. (The test times are ordered later-to-earlier, but this routine
+ * doesn't actually know that; it just scans until the first non-match.)
+ *
+ * We return -1 for a completely unusable setting; this is worse than the
+ * score of zero for a setting that works but matches not even the first
+ * test time.
+ */
+static int
+score_timezone(const char *tzname, struct tztry * tt)
+{
+ int i;
+ pg_time_t pgtt;
+ struct tm *systm;
+ struct pg_tm *pgtm;
+ char cbuf[TZ_STRLEN_MAX + 1];
+ pg_tz *tz;
+
+ /* Load timezone definition */
+ tz = pg_load_tz(tzname);
+ if (!tz)
+ return -1; /* unrecognized zone name */
+
+ /* Reject if leap seconds involved */
+ if (!pg_tz_acceptable(tz))
+ {
+#ifdef DEBUG_IDENTIFY_TIMEZONE
+ fprintf(stderr, "Reject TZ \"%s\": uses leap seconds\n", tzname);
+#endif
+ return -1;
+ }
+
+ /* Check for match at all the test times */
+ for (i = 0; i < tt->n_test_times; i++)
+ {
+ pgtt = (pg_time_t) (tt->test_times[i]);
+ pgtm = pg_localtime(&pgtt, tz);
+ if (!pgtm)
+ return -1; /* probably shouldn't happen */
+ systm = localtime(&(tt->test_times[i]));
+ if (!systm)
+ {
+#ifdef DEBUG_IDENTIFY_TIMEZONE
+ fprintf(stderr, "TZ \"%s\" scores %d: at %ld %04d-%02d-%02d %02d:%02d:%02d %s, system had no data\n",
+ tzname, i, (long) pgtt,
+ pgtm->tm_year + 1900, pgtm->tm_mon + 1, pgtm->tm_mday,
+ pgtm->tm_hour, pgtm->tm_min, pgtm->tm_sec,
+ pgtm->tm_isdst ? "dst" : "std");
+#endif
+ return i;
+ }
+ if (!compare_tm(systm, pgtm))
+ {
+#ifdef DEBUG_IDENTIFY_TIMEZONE
+ fprintf(stderr, "TZ \"%s\" scores %d: at %ld %04d-%02d-%02d %02d:%02d:%02d %s versus %04d-%02d-%02d %02d:%02d:%02d %s\n",
+ tzname, i, (long) pgtt,
+ pgtm->tm_year + 1900, pgtm->tm_mon + 1, pgtm->tm_mday,
+ pgtm->tm_hour, pgtm->tm_min, pgtm->tm_sec,
+ pgtm->tm_isdst ? "dst" : "std",
+ systm->tm_year + 1900, systm->tm_mon + 1, systm->tm_mday,
+ systm->tm_hour, systm->tm_min, systm->tm_sec,
+ systm->tm_isdst ? "dst" : "std");
+#endif
+ return i;
+ }
+ if (systm->tm_isdst >= 0)
+ {
+ /* Check match of zone names, too */
+ if (pgtm->tm_zone == NULL)
+ return -1; /* probably shouldn't happen */
+ memset(cbuf, 0, sizeof(cbuf));
+ strftime(cbuf, sizeof(cbuf) - 1, "%Z", systm); /* zone abbr */
+ if (strcmp(cbuf, pgtm->tm_zone) != 0)
+ {
+#ifdef DEBUG_IDENTIFY_TIMEZONE
+ fprintf(stderr, "TZ \"%s\" scores %d: at %ld \"%s\" versus \"%s\"\n",
+ tzname, i, (long) pgtt,
+ pgtm->tm_zone, cbuf);
+#endif
+ return i;
+ }
+ }
+ }
+
+#ifdef DEBUG_IDENTIFY_TIMEZONE
+ fprintf(stderr, "TZ \"%s\" gets max score %d\n", tzname, i);
+#endif
+
+ return i;
+}
+
+
+/*
+ * Try to identify a timezone name (in our terminology) that best matches the
+ * observed behavior of the system timezone library. We cannot assume that
+ * 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 const char *
+identify_system_timezone(void)
+{
+ static char resultbuf[TZ_STRLEN_MAX + 1];
+ time_t tnow;
+ time_t t;
+ struct tztry tt;
+ struct tm *tm;
+ int thisyear;
+ int bestscore;
+ char tmptzdir[MAXPGPATH];
+ int std_ofs;
+ char std_zone_name[TZ_STRLEN_MAX + 1],
+ dst_zone_name[TZ_STRLEN_MAX + 1];
+ char cbuf[TZ_STRLEN_MAX + 1];
+
+ /* Initialize OS timezone library */
+ tzset();
+
+ /*
+ * Set up the list of dates to be probed to see how well our timezone
+ * matches the system zone. We first probe January and July of the
+ * current year; this serves to quickly eliminate the vast majority of the
+ * TZ database entries. If those dates match, we probe every week for 100
+ * years backwards from the current July. (Weekly resolution is good
+ * enough to identify DST transition rules, since everybody switches on
+ * Sundays.) This is sufficient to cover most of the Unix time_t range,
+ * and we don't want to look further than that since many systems won't
+ * have sane TZ behavior further back anyway. 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 system-supplied
+ * timezone definitions are likely to have DST behavior that is right for
+ * the recent past and not so accurate further back. Scoring in this way
+ * allows us to recognize zones that have some commonality with the Olson
+ * database, without insisting on exact match. (Note: we probe Thursdays,
+ * not Sundays, to avoid triggering DST-transition bugs in localtime
+ * itself.)
+ */
+ tnow = time(NULL);
+ tm = localtime(&tnow);
+ if (!tm)
+ return NULL; /* give up if localtime is broken... */
+ thisyear = tm->tm_year + 1900;
+
+ t = build_time_t(thisyear, 1, 15);
+
+ /*
+ * Round back to GMT midnight Thursday. This depends on the knowledge
+ * that the time_t origin is Thu Jan 01 1970. (With a different origin
+ * we'd be probing some other day of the week, but it wouldn't matter
+ * anyway unless localtime() had DST-transition bugs.)
+ */
+ t -= (t % T_WEEK);
+
+ tt.n_test_times = 0;
+ tt.test_times[tt.n_test_times++] = t;
+
+ t = build_time_t(thisyear, 7, 15);
+ t -= (t % T_WEEK);
+
+ tt.test_times[tt.n_test_times++] = t;
+
+ while (tt.n_test_times < MAX_TEST_TIMES)
+ {
+ t -= T_WEEK;
+ tt.test_times[tt.n_test_times++] = t;
+ }
+
+ /* Search for the best-matching timezone file */
+ strcpy(tmptzdir, pg_TZDIR());
+ bestscore = -1;
+ resultbuf[0] = '\0';
+ scan_available_timezones(tmptzdir, tmptzdir + strlen(tmptzdir) + 1,
+ &tt,
+ &bestscore, resultbuf);
+ if (bestscore > 0)
+ {
+ /* Ignore Olson's rather silly "Factory" zone; use GMT instead */
+ if (strcmp(resultbuf, "Factory") == 0)
+ return NULL;
+ return resultbuf;
+ }
+
+ /*
+ * Couldn't find a match in the database, so next we try constructed zone
+ * names (like "PST8PDT").
+ *
+ * First we need to determine the names of the local standard and daylight
+ * zones. The idea here is to scan forward from today until we have seen
+ * both zones, if both are in use.
+ */
+ memset(std_zone_name, 0, sizeof(std_zone_name));
+ memset(dst_zone_name, 0, sizeof(dst_zone_name));
+ std_ofs = 0;
+
+ tnow = time(NULL);
+
+ /*
+ * Round back to a GMT midnight so results don't depend on local time of
+ * day
+ */
+ tnow -= (tnow % T_DAY);
+
+ /*
+ * We have to look a little further ahead than one year, in case today is
+ * just past a DST boundary that falls earlier in the year than the next
+ * similar boundary. Arbitrarily scan up to 14 months.
+ */
+ for (t = tnow; t <= tnow + T_MONTH * 14; t += T_MONTH)
+ {
+ tm = localtime(&t);
+ if (!tm)
+ continue;
+ if (tm->tm_isdst < 0)
+ continue;
+ if (tm->tm_isdst == 0 && std_zone_name[0] == '\0')
+ {
+ /* found STD zone */
+ memset(cbuf, 0, sizeof(cbuf));
+ strftime(cbuf, sizeof(cbuf) - 1, "%Z", tm); /* zone abbr */
+ 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, cbuf);
+ }
+ /* Done if found both */
+ if (std_zone_name[0] && dst_zone_name[0])
+ break;
+ }
+
+ /* We should have found a STD zone name by now... */
+ if (std_zone_name[0] == '\0')
+ {
+#ifdef DEBUG_IDENTIFY_TIMEZONE
+ fprintf(stderr, "could not determine system time zone\n");
+#endif
+ return NULL; /* go to GMT */
+ }
+
+ /* If we found DST then try STD<ofs>DST */
+ if (dst_zone_name[0] != '\0')
+ {
+ snprintf(resultbuf, sizeof(resultbuf), "%s%d%s",
+ std_zone_name, -std_ofs / 3600, dst_zone_name);
+ if (score_timezone(resultbuf, &tt) > 0)
+ return resultbuf;
+ }
+
+ /* Try just the STD timezone (works for GMT at least) */
+ strcpy(resultbuf, std_zone_name);
+ if (score_timezone(resultbuf, &tt) > 0)
+ return resultbuf;
+
+ /* Try STD<ofs> */
+ snprintf(resultbuf, sizeof(resultbuf), "%s%d",
+ std_zone_name, -std_ofs / 3600);
+ if (score_timezone(resultbuf, &tt) > 0)
+ return resultbuf;
+
+ /*
+ * Did not find the timezone. Fallback to use a GMT zone. Note that the
+ * Olson timezone database names the GMT-offset zones in POSIX style: plus
+ * is west of Greenwich. It's unfortunate that this is opposite of SQL
+ * conventions. Should we therefore change the names? Probably not...
+ */
+ snprintf(resultbuf, sizeof(resultbuf), "Etc/GMT%s%d",
+ (-std_ofs > 0) ? "+" : "", -std_ofs / 3600);
+
+#ifdef DEBUG_IDENTIFY_TIMEZONE
+ fprintf(stderr, "could not recognize system time zone, using \"%s\"\n",
+ resultbuf);
+#endif
+ return resultbuf;
+}
+
+/*
+ * Recursively scan the timezone database looking for the best match to
+ * the system timezone behavior.
+ *
+ * tzdir points to a buffer of size MAXPGPATH. On entry, it holds the
+ * pathname of a directory containing TZ files. We internally modify it
+ * to hold pathnames of sub-directories and files, but must restore it
+ * to its original contents before exit.
+ *
+ * tzdirsub points to the part of tzdir that represents the subfile name
+ * (ie, tzdir + the original directory name length, plus one for the
+ * first added '/').
+ *
+ * tt tells about the system timezone behavior we need to match.
+ *
+ * *bestscore and *bestzonename on entry hold the best score found so far
+ * and the name of the best zone. We overwrite them if we find a better
+ * score. bestzonename must be a buffer of length TZ_STRLEN_MAX + 1.
+ */
+static void
+scan_available_timezones(char *tzdir, char *tzdirsub, struct tztry * tt,
+ int *bestscore, char *bestzonename)
+{
+ int tzdir_orig_len = strlen(tzdir);
+ char **names;
+ char **namep;
+
+ names = pgfnames(tzdir);
+ if (!names)
+ return;
+
+ for (namep = names; *namep; namep++)
+ {
+ char *name = *namep;
+ struct stat statbuf;
+
+ /* Ignore . and .., plus any other "hidden" files */
+ if (name[0] == '.')
+ continue;
+
+ snprintf(tzdir + tzdir_orig_len, MAXPGPATH - tzdir_orig_len,
+ "/%s", name);
+
+ if (stat(tzdir, &statbuf) != 0)
+ {
+#ifdef DEBUG_IDENTIFY_TIMEZONE
+ fprintf(stderr, "could not stat \"%s\": %s\n",
+ tzdir, strerror(errno));
+#endif
+ tzdir[tzdir_orig_len] = '\0';
+ continue;
+ }
+
+ if (S_ISDIR(statbuf.st_mode))
+ {
+ /* Recurse into subdirectory */
+ scan_available_timezones(tzdir, tzdirsub, tt,
+ bestscore, bestzonename);
+ }
+ else
+ {
+ /* Load and test this file */
+ int score = score_timezone(tzdirsub, tt);
+
+ if (score > *bestscore)
+ {
+ *bestscore = score;
+ strlcpy(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))
+ strlcpy(bestzonename, tzdirsub, TZ_STRLEN_MAX + 1);
+ }
+ }
+
+ /* Restore tzdir */
+ tzdir[tzdir_orig_len] = '\0';
+ }
+
+ pgfnames_cleanup(names);
+}
+
+#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 2003 R2.
+ *
+ * The zones have been matched to Olson 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 */
+ {
+ "Argentina Standard Time", "Argentina Daylight Time",
+ "America/Buenos_Aires"
+ }, /* (GMT-03:00) Buenos Aires */
+ {
+ "Armenian Standard Time", "Armenian Daylight Time",
+ "Asia/Yerevan"
+ }, /* (GMT+04:00) Yerevan */
+ {
+ "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 */
+ {
+ "Azerbaijan Standard Time", "Azerbaijan Daylight Time",
+ "Asia/Baku"
+ }, /* (GMT+04:00) Baku */
+ {
+ "Azores Standard Time", "Azores Daylight Time",
+ "Atlantic/Azores"
+ }, /* (GMT-01:00) Azores */
+ {
+ "Bangladesh Standard Time", "Bangladesh Daylight Time",
+ "Asia/Dhaka"
+ }, /* (GMT+06:00) Dhaka */
+ {
+ "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 Brazilian Standard Time", "Central Brazilian Daylight Time",
+ "America/Cuiaba"
+ }, /* (GMT-04:00) Cuiaba */
+ {
+ "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) */
+ {
+ "Central Standard Time (Mexico)", "Central Daylight Time (Mexico)",
+ "America/Mexico_City"
+ }, /* (GMT-06:00) Guadalajara, Mexico City,
+ * Monterrey - New */
+ {
+ "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 */
+ {
+ "Georgian Standard Time", "Georgian Daylight Time",
+ "Asia/Tbilisi"
+ }, /* (GMT+03:00) Tbilisi */
+ {
+ "GMT Standard Time", "GMT Daylight Time",
+ "Europe/London"
+ }, /* (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 */
+ {
+ "Jordan Standard Time", "Jordan Daylight Time",
+ "Asia/Amman"
+ }, /* (GMT+02:00) Amman */
+ {
+ "Kamchatka Standard Time", "Kamchatka Daylight Time",
+ "Asia/Kamchatka"
+ }, /* (GMT+12:00) Petropavlovsk-Kamchatsky */
+ {
+ "Korea Standard Time", "Korea Daylight Time",
+ "Asia/Seoul"
+ }, /* (GMT+09:00) Seoul */
+ {
+ "Mauritius Standard Time", "Mauritius Daylight Time",
+ "Indian/Mauritius"
+ }, /* (GMT+04:00) Port Louis */
+ {
+ "Mexico Standard Time", "Mexico Daylight Time",
+ "America/Mexico_City"
+ }, /* (GMT-06:00) Guadalajara, Mexico City,
+ * Monterrey */
+ {
+ "Mexico Standard Time 2", "Mexico Daylight Time 2",
+ "America/Chihuahua"
+ }, /* (GMT-07:00) Chihuahua, La Paz, Mazatlan */
+ {
+ "Mid-Atlantic Standard Time", "Mid-Atlantic Daylight Time",
+ "Atlantic/South_Georgia"
+ }, /* (GMT-02:00) Mid-Atlantic */
+ {
+ "Middle East Standard Time", "Middle East Daylight Time",
+ "Asia/Beirut"
+ }, /* (GMT+02:00) Beirut */
+ {
+ "Montevideo Standard Time", "Montevideo Daylight Time",
+ "America/Montevideo"
+ }, /* (GMT-03:00) Montevideo */
+ {
+ "Morocco Standard Time", "Morocco Daylight Time",
+ "Africa/Casablanca"
+ }, /* (GMT) Casablanca */
+ {
+ "Mountain Standard Time", "Mountain Daylight Time",
+ "US/Mountain"
+ }, /* (GMT-07:00) Mountain Time (US & Canada) */
+ {
+ "Mountain Standard Time (Mexico)", "Mountain Daylight Time (Mexico)",
+ "America/Chihuahua"
+ }, /* (GMT-07:00) Chihuahua, La Paz, Mazatlan -
+ * New */
+ {
+ "Myanmar Standard Time", "Myanmar Daylight Time",
+ "Asia/Rangoon"
+ }, /* (GMT+06:30) Rangoon */
+ {
+ "N. Central Asia Standard Time", "N. Central Asia Daylight Time",
+ "Asia/Novosibirsk"
+ }, /* (GMT+06:00) Novosibirsk */
+ {
+ "Namibia Standard Time", "Namibia Daylight Time",
+ "Africa/Windhoek"
+ }, /* (GMT+02:00) Windhoek */
+ {
+ "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 */
+ {
+ "Pacific Standard Time (Mexico)", "Pacific Daylight Time (Mexico)",
+ "America/Tijuana"
+ }, /* (GMT-08:00) Tijuana, Baja California */
+ {
+ "Pakistan Standard Time", "Pakistan Daylight Time",
+ "Asia/Karachi"
+ }, /* (GMT+05:00) Islamabad, Karachi */
+ {
+ "Paraguay Standard Time", "Paraguay Daylight Time",
+ "America/Asuncion"
+ }, /* (GMT-04:00) Asuncion */
+ {
+ "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 */
+ {
+ "Ulaanbaatar Standard Time", "Ulaanbaatar Daylight Time",
+ "Asia/Ulaanbaatar",
+ }, /* (GMT+08:00) Ulaanbaatar */
+ {
+ "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 */
+ {
+ "Coordinated Universal Time", "Coordinated Universal Time",
+ "UTC"
+ }, /* (GMT) Coordinated Universal Time */
+ {
+ "UTC+12", "UTC+12",
+ "Etc/GMT+12"
+ }, /* (GMT+12:00) Coordinated Universal Time+12 */
+ {
+ "UTC-02", "UTC-02",
+ "Etc/GMT-02"
+ }, /* (GMT-02:00) Coordinated Universal Time-02 */
+ {
+ "UTC-11", "UTC-11",
+ "Etc/GMT-11"
+ }, /* (GMT-11:00) Coordinated Universal Time-11 */
+ {
+ "Venezuela Standard Time", "Venezuela Daylight Time",
+ "America/Caracas",
+ }, /* (GMT-04:30) Caracas */
+ {
+ "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 */
+#ifdef NOT_USED
+ /* Could not find a match for this one (just a guess). Excluded for now. */
+ {
+ "W. Central Africa Standard Time", "W. Central Africa Daylight Time",
+ "WAT"
+ }, /* (GMT+01:00) West Central Africa */
+#endif
+ {
+ "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];
+ char localtzname[256];
+ time_t t = time(NULL);
+ struct tm *tm = localtime(&t);
+ HKEY rootKey;
+ int idx;
+
+ if (!tm)
+ {
+#ifdef DEBUG_IDENTIFY_TIMEZONE
+ fprintf(stderr, "could not identify system time zone: localtime() failed\n");
+#endif
+ return NULL; /* go to GMT */
+ }
+
+ 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)
+ {
+#ifdef DEBUG_IDENTIFY_TIMEZONE
+ fprintf(stderr, "TZ \"%s\" matches system time zone \"%s\"\n",
+ win32_tzmap[i].pgtzname, tzname);
+#endif
+ return win32_tzmap[i].pgtzname;
+ }
+ }
+
+ /*
+ * Localized Windows versions return localized names for the timezone.
+ * Scan the registry to find the English name, and then try matching
+ * against our table again.
+ */
+ memset(localtzname, 0, sizeof(localtzname));
+ if (RegOpenKeyEx(HKEY_LOCAL_MACHINE,
+ "SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion\\Time Zones",
+ 0,
+ KEY_READ,
+ &rootKey) != ERROR_SUCCESS)
+ {
+#ifdef DEBUG_IDENTIFY_TIMEZONE
+ fprintf(stderr, "could not open registry key to identify system time zone: error code %lu\n",
+ GetLastError());
+#endif
+ return NULL; /* go to GMT */
+ }
+
+ for (idx = 0;; idx++)
+ {
+ char keyname[256];
+ char zonename[256];
+ DWORD namesize;
+ FILETIME lastwrite;
+ HKEY key;
+ LONG r;
+
+ memset(keyname, 0, sizeof(keyname));
+ namesize = sizeof(keyname);
+ if ((r = RegEnumKeyEx(rootKey,
+ idx,
+ keyname,
+ &namesize,
+ NULL,
+ NULL,
+ NULL,
+ &lastwrite)) != ERROR_SUCCESS)
+ {
+ if (r == ERROR_NO_MORE_ITEMS)
+ break;
+#ifdef DEBUG_IDENTIFY_TIMEZONE
+ fprintf(stderr, "could not enumerate registry subkeys to identify system time zone: %d\n",
+ (int) r);
+#endif
+ break;
+ }
+
+ if ((r = RegOpenKeyEx(rootKey, keyname, 0, KEY_READ, &key)) != ERROR_SUCCESS)
+ {
+#ifdef DEBUG_IDENTIFY_TIMEZONE
+ fprintf(stderr, "could not open registry subkey to identify system time zone: %d\n",
+ (int) r);
+#endif
+ break;
+ }
+
+ memset(zonename, 0, sizeof(zonename));
+ namesize = sizeof(zonename);
+ if ((r = RegQueryValueEx(key, "Std", NULL, NULL, (unsigned char *) zonename, &namesize)) != ERROR_SUCCESS)
+ {
+#ifdef DEBUG_IDENTIFY_TIMEZONE
+ fprintf(stderr, "could not query value for key \"std\" to identify system time zone \"%s\": %d\n",
+ keyname, (int) r);
+#endif
+ RegCloseKey(key);
+ continue; /* Proceed to look at the next timezone */
+ }
+ if (strcmp(tzname, zonename) == 0)
+ {
+ /* Matched zone */
+ strcpy(localtzname, keyname);
+ RegCloseKey(key);
+ break;
+ }
+ memset(zonename, 0, sizeof(zonename));
+ namesize = sizeof(zonename);
+ if ((r = RegQueryValueEx(key, "Dlt", NULL, NULL, (unsigned char *) zonename, &namesize)) != ERROR_SUCCESS)
+ {
+#ifdef DEBUG_IDENTIFY_TIMEZONE
+ fprintf(stderr, "could not query value for key \"dlt\" to identify system time zone \"%s\": %d\n",
+ keyname, (int) r);
+#endif
+ RegCloseKey(key);
+ continue; /* Proceed to look at the next timezone */
+ }
+ if (strcmp(tzname, zonename) == 0)
+ {
+ /* Matched DST zone */
+ strcpy(localtzname, keyname);
+ RegCloseKey(key);
+ break;
+ }
+
+ RegCloseKey(key);
+ }
+
+ RegCloseKey(rootKey);
+
+ if (localtzname[0])
+ {
+ /* Found a localized name, so scan for that one too */
+ for (i = 0; win32_tzmap[i].stdname != NULL; i++)
+ {
+ if (strcmp(localtzname, win32_tzmap[i].stdname) == 0 ||
+ strcmp(localtzname, win32_tzmap[i].dstname) == 0)
+ {
+#ifdef DEBUG_IDENTIFY_TIMEZONE
+ fprintf(stderr, "TZ \"%s\" matches localized system time zone \"%s\" (\"%s\")\n",
+ win32_tzmap[i].pgtzname, tzname, localtzname);
+#endif
+ return win32_tzmap[i].pgtzname;
+ }
+ }
+ }
+
+#ifdef DEBUG_IDENTIFY_TIMEZONE
+ fprintf(stderr, "could not find a match for system time zone \"%s\"\n",
+ tzname);
+#endif
+ return NULL; /* go to GMT */
+}
+#endif /* WIN32 */
+
+
+/*
+ * Return true if the given zone name is valid and is an "acceptable" zone.
+ */
+static bool
+validate_zone(const char *tzname)
+{
+ pg_tz *tz;
+
+ if (!tzname || !tzname[0])
+ return false;
+
+ tz = pg_load_tz(tzname);
+ if (!tz)
+ return false;
+
+ if (!pg_tz_acceptable(tz))
+ return false;
+
+ return true;
+}
+
+/*
+ * Identify a suitable default timezone setting based on the environment.
+ *
+ * The installation share_path must be passed in, as that is the default
+ * location for the timezone database directory.
+ *
+ * We first look to the TZ environment variable. If not found or not
+ * recognized by our own code, we see if we can identify the timezone
+ * from the behavior of the system timezone library. When all else fails,
+ * return NULL, indicating that we should default to GMT.
+ */
+const char *
+select_default_timezone(const char *share_path)
+{
+ const char *tzname;
+
+ /* Initialize timezone directory path, if needed */
+#ifndef SYSTEMTZDIR
+ snprintf(tzdirpath, sizeof(tzdirpath), "%s/timezone", share_path);
+#endif
+
+ /* Check TZ environment variable */
+ tzname = getenv("TZ");
+ if (validate_zone(tzname))
+ return tzname;
+
+ /* Nope, so try to identify the system timezone */
+ tzname = identify_system_timezone();
+ if (validate_zone(tzname))
+ return tzname;
+
+ return NULL;
+}
#include "getopt_long.h"
#include "miscadmin.h"
+/* Ideally this would be in a .h file, but it hardly seems worth the trouble */
+extern const char *select_default_timezone(const char *share_path);
+
/*
* these values are passed in by makefile defines
setup_config(void)
{
char **conflines;
- char repltok[100];
+ char repltok[TZ_STRLEN_MAX + 100];
char path[MAXPGPATH];
+ const char *default_timezone;
fputs(_("creating configuration files ... "), stdout);
fflush(stdout);
"#default_text_search_config = 'pg_catalog.simple'",
repltok);
+ default_timezone = select_default_timezone(share_path);
+ if (default_timezone)
+ {
+ snprintf(repltok, sizeof(repltok), "timezone = '%s'",
+ escape_quotes(default_timezone));
+ conflines = replace_token(conflines, "#timezone = 'GMT'", repltok);
+ snprintf(repltok, sizeof(repltok), "log_timezone = '%s'",
+ escape_quotes(default_timezone));
+ conflines = replace_token(conflines, "#log_timezone = 'GMT'", repltok);
+ }
+
snprintf(path, sizeof(path), "%s/postgresql.conf", pg_data);
writefile(path, conflines);
sprintf(pgdenv, "PGDATA=%s", pg_data);
putenv(pgdenv);
- /*
- * Also ensure that TZ is set, so that we don't waste time identifying the
- * system timezone each of the many times we start a standalone backend.
- * It's okay to use a hard-wired value here because nothing done during
- * initdb cares about the timezone setting.
- */
- putenv("TZ=GMT");
-
if ((ret = find_other_exec(argv[0], "postgres", PG_BACKEND_VERSIONSTR,
backend_exec)) < 0)
{
typedef struct pg_tz pg_tz;
typedef struct pg_tzenum pg_tzenum;
+/* Maximum length of a timezone name (not including trailing null) */
+#define TZ_STRLEN_MAX 255
+
+/* these functions are in localtime.c */
+
extern struct pg_tm *pg_localtime(const pg_time_t *timep, const pg_tz *tz);
extern struct pg_tm *pg_gmtime(const pg_time_t *timep);
extern int pg_next_dst_boundary(const pg_time_t *timep,
extern size_t pg_strftime(char *s, size_t max, const char *format,
const struct pg_tm * tm);
-extern void pg_timezone_pre_initialize(void);
-extern void pg_timezone_initialize(void);
-extern pg_tz *pg_tzset(const char *tzname);
-extern bool tz_acceptable(pg_tz *tz);
extern bool pg_get_timezone_offset(const pg_tz *tz, long int *gmtoff);
extern const char *pg_get_timezone_name(pg_tz *tz);
+extern bool pg_tz_acceptable(pg_tz *tz);
-extern pg_tzenum *pg_tzenumerate_start(void);
-extern pg_tz *pg_tzenumerate_next(pg_tzenum *dir);
-extern void pg_tzenumerate_end(pg_tzenum *dir);
+/* these functions and variables are in pgtz.c */
extern pg_tz *session_timezone;
extern pg_tz *log_timezone;
-extern pg_tz *gmt_timezone;
-/* Maximum length of a timezone name (not including trailing null) */
-#define TZ_STRLEN_MAX 255
+extern void pg_timezone_initialize(void);
+extern pg_tz *pg_tzset(const char *tzname);
+
+extern pg_tzenum *pg_tzenumerate_start(void);
+extern pg_tz *pg_tzenumerate_next(pg_tzenum *dir);
+extern void pg_tzenumerate_end(pg_tzenum *dir);
#endif /* _PGTIME_H */
extern ArrayType *GUCArrayDelete(ArrayType *array, const char *name);
extern ArrayType *GUCArrayReset(ArrayType *array);
-extern void pg_timezone_abbrev_initialize(void);
-
#ifdef EXEC_BACKEND
extern void write_nondefault_variables(GucContext context);
extern void read_nondefault_variables(void);
#include <fcntl.h>
+#include "datatype/timestamp.h"
#include "private.h"
#include "pgtz.h"
#include "tzfile.h"
* can't assume pg_open_tzfile() is sane yet, and we don't care about
* leap seconds anyway.
*/
+ sp->goback = sp->goahead = FALSE;
load_result = -1;
}
else
return tz->TZname;
return NULL;
}
+
+/*
+ * Check whether timezone is acceptable.
+ *
+ * What we are doing here is checking for leap-second-aware timekeeping.
+ * We need to reject such TZ settings because they'll wreak havoc with our
+ * date/time arithmetic.
+ */
+bool
+pg_tz_acceptable(pg_tz *tz)
+{
+ struct pg_tm *tt;
+ pg_time_t time2000;
+
+ /*
+ * To detect leap-second timekeeping, run pg_localtime for what should be
+ * GMT midnight, 2000-01-01. Insist that the tm_sec value be zero; any
+ * other result has to be due to leap seconds.
+ */
+ time2000 = (POSTGRES_EPOCH_JDATE - UNIX_EPOCH_JDATE) * SECS_PER_DAY;
+ tt = pg_localtime(&time2000, tz);
+ if (!tt || tt->tm_sec != 0)
+ return false;
+
+ return true;
+}
*
*-------------------------------------------------------------------------
*/
-#define NO_REDEFINE_TIMEFUNCS
-
#include "postgres.h"
#include <ctype.h>
#include "miscadmin.h"
#include "pgtz.h"
#include "storage/fd.h"
-#include "tzfile.h"
-#include "utils/datetime.h"
-#include "utils/guc.h"
#include "utils/hsearch.h"
+
/* Current session timezone (controlled by TimeZone GUC) */
pg_tz *session_timezone = NULL;
/* Current log timezone (controlled by log_timezone GUC) */
pg_tz *log_timezone = NULL;
-/* Fallback GMT timezone for last-ditch error message formatting */
-pg_tz *gmt_timezone = NULL;
-static pg_tz gmt_timezone_data;
-
static bool scan_directory_ci(const char *dirname,
const char *fname, int fnamelen,
char *canonname, int canonnamelen);
-static const char *identify_system_timezone(void);
-static pg_tz *get_pg_tz_for_zone(const char *tzname);
-static pg_tz *select_default_timezone(void);
/*
* timezone database does not contain case-equivalent names).
*
* If "canonname" is not NULL, then on success the canonical spelling of the
- * given name is stored there (it is assumed to be > TZ_STRLEN_MAX bytes!).
+ * given name is stored there (the buffer must be > TZ_STRLEN_MAX bytes!).
*/
int
pg_open_tzfile(const char *name, char *canonname)
}
-/*
- * 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 */
-
-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
- */
-static int
-get_timezone_offset(struct tm * tm)
-{
-#if defined(HAVE_STRUCT_TM_TM_ZONE)
- return tm->tm_gmtoff;
-#elif defined(HAVE_INT_TIMEZONE)
- return -TIMEZONE_GLOBAL;
-#else
-#error No way to determine TZ? Can this happen?
-#endif
-}
-
-/*
- * Convenience subroutine to convert y/m/d to time_t (NOT pg_time_t)
- */
-static time_t
-build_time_t(int year, int month, int day)
-{
- struct tm tm;
-
- memset(&tm, 0, sizeof(tm));
- tm.tm_mday = day;
- tm.tm_mon = month - 1;
- tm.tm_year = year - 1900;
-
- return mktime(&tm);
-}
-
-/*
- * Does a system tm value match one we computed ourselves?
- */
-static bool
-compare_tm(struct tm * s, struct pg_tm * p)
-{
- if (s->tm_sec != p->tm_sec ||
- s->tm_min != p->tm_min ||
- s->tm_hour != p->tm_hour ||
- s->tm_mday != p->tm_mday ||
- s->tm_mon != p->tm_mon ||
- s->tm_year != p->tm_year ||
- s->tm_wday != p->tm_wday ||
- s->tm_yday != p->tm_yday ||
- s->tm_isdst != p->tm_isdst)
- return false;
- return true;
-}
-
-/*
- * See how well a specific timezone setting matches the system behavior
- *
- * We score a timezone setting according to the number of test times it
- * matches. (The test times are ordered later-to-earlier, but this routine
- * doesn't actually know that; it just scans until the first non-match.)
- *
- * We return -1 for a completely unusable setting; this is worse than the
- * score of zero for a setting that works but matches not even the first
- * test time.
- */
-static int
-score_timezone(const char *tzname, struct tztry * tt)
-{
- int i;
- pg_time_t pgtt;
- struct tm *systm;
- struct pg_tm *pgtm;
- char cbuf[TZ_STRLEN_MAX + 1];
- pg_tz tz;
-
-
- /*
- * Load timezone directly. Don't use pg_tzset, because we don't want all
- * timezones loaded in the cache at startup.
- */
- if (tzload(tzname, NULL, &tz.state, TRUE) != 0)
- {
- if (tzname[0] == ':' || tzparse(tzname, &tz.state, FALSE) != 0)
- {
- return -1; /* can't handle the TZ name at all */
- }
- }
-
- /* Reject if leap seconds involved */
- if (!tz_acceptable(&tz))
- {
- elog(DEBUG4, "Reject TZ \"%s\": uses leap seconds", tzname);
- return -1;
- }
-
- /* Check for match at all the test times */
- for (i = 0; i < tt->n_test_times; i++)
- {
- pgtt = (pg_time_t) (tt->test_times[i]);
- pgtm = pg_localtime(&pgtt, &tz);
- if (!pgtm)
- return -1; /* probably shouldn't happen */
- systm = localtime(&(tt->test_times[i]));
- if (!systm)
- {
- elog(DEBUG4, "TZ \"%s\" scores %d: at %ld %04d-%02d-%02d %02d:%02d:%02d %s, system had no data",
- tzname, i, (long) pgtt,
- pgtm->tm_year + 1900, pgtm->tm_mon + 1, pgtm->tm_mday,
- pgtm->tm_hour, pgtm->tm_min, pgtm->tm_sec,
- pgtm->tm_isdst ? "dst" : "std");
- return i;
- }
- if (!compare_tm(systm, pgtm))
- {
- elog(DEBUG4, "TZ \"%s\" scores %d: at %ld %04d-%02d-%02d %02d:%02d:%02d %s versus %04d-%02d-%02d %02d:%02d:%02d %s",
- tzname, i, (long) pgtt,
- pgtm->tm_year + 1900, pgtm->tm_mon + 1, pgtm->tm_mday,
- pgtm->tm_hour, pgtm->tm_min, pgtm->tm_sec,
- pgtm->tm_isdst ? "dst" : "std",
- systm->tm_year + 1900, systm->tm_mon + 1, systm->tm_mday,
- systm->tm_hour, systm->tm_min, systm->tm_sec,
- systm->tm_isdst ? "dst" : "std");
- return i;
- }
- if (systm->tm_isdst >= 0)
- {
- /* Check match of zone names, too */
- if (pgtm->tm_zone == NULL)
- return -1; /* probably shouldn't happen */
- memset(cbuf, 0, sizeof(cbuf));
- strftime(cbuf, sizeof(cbuf) - 1, "%Z", systm); /* zone abbr */
- if (strcmp(cbuf, pgtm->tm_zone) != 0)
- {
- elog(DEBUG4, "TZ \"%s\" scores %d: at %ld \"%s\" versus \"%s\"",
- tzname, i, (long) pgtt,
- pgtm->tm_zone, cbuf);
- return i;
- }
- }
- }
-
- elog(DEBUG4, "TZ \"%s\" gets max score %d", tzname, i);
- return i;
-}
-
-
-/*
- * Try to identify a timezone name (in our terminology) that best matches the
- * observed behavior of the system timezone library. We cannot assume that
- * 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 const char *
-identify_system_timezone(void)
-{
- static char resultbuf[TZ_STRLEN_MAX + 1];
- time_t tnow;
- time_t t;
- struct tztry tt;
- struct tm *tm;
- int thisyear;
- int bestscore;
- char tmptzdir[MAXPGPATH];
- int std_ofs;
- char std_zone_name[TZ_STRLEN_MAX + 1],
- dst_zone_name[TZ_STRLEN_MAX + 1];
- char cbuf[TZ_STRLEN_MAX + 1];
-
- /* Initialize OS timezone library */
- tzset();
-
- /*
- * Set up the list of dates to be probed to see how well our timezone
- * matches the system zone. We first probe January and July of the
- * current year; this serves to quickly eliminate the vast majority of the
- * TZ database entries. If those dates match, we probe every week for 100
- * years backwards from the current July. (Weekly resolution is good
- * enough to identify DST transition rules, since everybody switches on
- * Sundays.) This is sufficient to cover most of the Unix time_t range,
- * and we don't want to look further than that since many systems won't
- * have sane TZ behavior further back anyway. 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 system-supplied
- * timezone definitions are likely to have DST behavior that is right for
- * the recent past and not so accurate further back. Scoring in this way
- * allows us to recognize zones that have some commonality with the zic
- * database, without insisting on exact match. (Note: we probe Thursdays,
- * not Sundays, to avoid triggering DST-transition bugs in localtime
- * itself.)
- */
- tnow = time(NULL);
- tm = localtime(&tnow);
- if (!tm)
- return NULL; /* give up if localtime is broken... */
- thisyear = tm->tm_year + 1900;
-
- t = build_time_t(thisyear, 1, 15);
-
- /*
- * Round back to GMT midnight Thursday. This depends on the knowledge
- * that the time_t origin is Thu Jan 01 1970. (With a different origin
- * we'd be probing some other day of the week, but it wouldn't matter
- * anyway unless localtime() had DST-transition bugs.)
- */
- t -= (t % T_WEEK);
-
- tt.n_test_times = 0;
- tt.test_times[tt.n_test_times++] = t;
-
- t = build_time_t(thisyear, 7, 15);
- t -= (t % T_WEEK);
-
- tt.test_times[tt.n_test_times++] = t;
-
- while (tt.n_test_times < MAX_TEST_TIMES)
- {
- t -= T_WEEK;
- tt.test_times[tt.n_test_times++] = t;
- }
-
- /* Search for the best-matching timezone file */
- strcpy(tmptzdir, pg_TZDIR());
- bestscore = -1;
- resultbuf[0] = '\0';
- scan_available_timezones(tmptzdir, tmptzdir + strlen(tmptzdir) + 1,
- &tt,
- &bestscore, resultbuf);
- if (bestscore > 0)
- {
- /* Ignore zic's rather silly "Factory" time zone; use GMT instead */
- if (strcmp(resultbuf, "Factory") == 0)
- return NULL;
- return resultbuf;
- }
-
- /*
- * Couldn't find a match in the database, so next we try constructed zone
- * names (like "PST8PDT").
- *
- * First we need to determine the names of the local standard and daylight
- * zones. The idea here is to scan forward from today until we have seen
- * both zones, if both are in use.
- */
- memset(std_zone_name, 0, sizeof(std_zone_name));
- memset(dst_zone_name, 0, sizeof(dst_zone_name));
- std_ofs = 0;
-
- tnow = time(NULL);
-
- /*
- * Round back to a GMT midnight so results don't depend on local time of
- * day
- */
- tnow -= (tnow % T_DAY);
-
- /*
- * We have to look a little further ahead than one year, in case today is
- * just past a DST boundary that falls earlier in the year than the next
- * similar boundary. Arbitrarily scan up to 14 months.
- */
- for (t = tnow; t <= tnow + T_MONTH * 14; t += T_MONTH)
- {
- tm = localtime(&t);
- if (!tm)
- continue;
- if (tm->tm_isdst < 0)
- continue;
- if (tm->tm_isdst == 0 && std_zone_name[0] == '\0')
- {
- /* found STD zone */
- memset(cbuf, 0, sizeof(cbuf));
- strftime(cbuf, sizeof(cbuf) - 1, "%Z", tm); /* zone abbr */
- 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, cbuf);
- }
- /* Done if found both */
- if (std_zone_name[0] && dst_zone_name[0])
- break;
- }
-
- /* We should have found a STD zone name by now... */
- if (std_zone_name[0] == '\0')
- {
- ereport(LOG,
- (errmsg("could not determine system time zone"),
- errdetail("The PostgreSQL time zone will be set to \"%s\".",
- "GMT"),
- errhint("You can specify the correct timezone in postgresql.conf.")));
- return NULL; /* go to GMT */
- }
-
- /* If we found DST then try STD<ofs>DST */
- if (dst_zone_name[0] != '\0')
- {
- snprintf(resultbuf, sizeof(resultbuf), "%s%d%s",
- std_zone_name, -std_ofs / 3600, dst_zone_name);
- if (score_timezone(resultbuf, &tt) > 0)
- return resultbuf;
- }
-
- /* Try just the STD timezone (works for GMT at least) */
- strcpy(resultbuf, std_zone_name);
- if (score_timezone(resultbuf, &tt) > 0)
- return resultbuf;
-
- /* Try STD<ofs> */
- snprintf(resultbuf, sizeof(resultbuf), "%s%d",
- std_zone_name, -std_ofs / 3600);
- if (score_timezone(resultbuf, &tt) > 0)
- return resultbuf;
-
- /*
- * Did not find the timezone. Fallback to use a GMT zone. Note that the
- * zic timezone database names the GMT-offset zones in POSIX style: plus
- * is west of Greenwich. It's unfortunate that this is opposite of SQL
- * conventions. Should we therefore change the names? Probably not...
- */
- snprintf(resultbuf, sizeof(resultbuf), "Etc/GMT%s%d",
- (-std_ofs > 0) ? "+" : "", -std_ofs / 3600);
-
- ereport(LOG,
- (errmsg("could not recognize system time zone"),
- errdetail("The PostgreSQL time zone will be set to \"%s\".",
- resultbuf),
- errhint("You can specify the correct timezone in postgresql.conf.")));
- return resultbuf;
-}
-
-/*
- * Recursively scan the timezone database looking for the best match to
- * the system timezone behavior.
- *
- * tzdir points to a buffer of size MAXPGPATH. On entry, it holds the
- * pathname of a directory containing TZ files. We internally modify it
- * to hold pathnames of sub-directories and files, but must restore it
- * to its original contents before exit.
- *
- * tzdirsub points to the part of tzdir that represents the subfile name
- * (ie, tzdir + the original directory name length, plus one for the
- * first added '/').
- *
- * tt tells about the system timezone behavior we need to match.
- *
- * *bestscore and *bestzonename on entry hold the best score found so far
- * and the name of the best zone. We overwrite them if we find a better
- * score. bestzonename must be a buffer of length TZ_STRLEN_MAX + 1.
- */
-static void
-scan_available_timezones(char *tzdir, char *tzdirsub, struct tztry * tt,
- int *bestscore, char *bestzonename)
-{
- int tzdir_orig_len = strlen(tzdir);
- DIR *dirdesc;
- struct dirent *direntry;
-
- dirdesc = AllocateDir(tzdir);
- if (!dirdesc)
- {
- ereport(LOG,
- (errcode_for_file_access(),
- errmsg("could not open directory \"%s\": %m", tzdir)));
- return;
- }
-
- while ((direntry = ReadDir(dirdesc, tzdir)) != NULL)
- {
- struct stat statbuf;
-
- /* Ignore . and .., plus any other "hidden" files */
- if (direntry->d_name[0] == '.')
- continue;
-
- snprintf(tzdir + tzdir_orig_len, MAXPGPATH - tzdir_orig_len,
- "/%s", direntry->d_name);
-
- if (stat(tzdir, &statbuf) != 0)
- {
- ereport(LOG,
- (errcode_for_file_access(),
- errmsg("could not stat \"%s\": %m", tzdir)));
- tzdir[tzdir_orig_len] = '\0';
- continue;
- }
-
- if (S_ISDIR(statbuf.st_mode))
- {
- /* Recurse into subdirectory */
- scan_available_timezones(tzdir, tzdirsub, tt,
- bestscore, bestzonename);
- }
- else
- {
- /* Load and test this file */
- int score = score_timezone(tzdirsub, tt);
-
- if (score > *bestscore)
- {
- *bestscore = score;
- strlcpy(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))
- strlcpy(bestzonename, tzdirsub, TZ_STRLEN_MAX + 1);
- }
- }
-
- /* Restore tzdir */
- tzdir[tzdir_orig_len] = '\0';
- }
-
- FreeDir(dirdesc);
-}
-#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 2003 R2.
- *
- * 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 */
- {
- "Argentina Standard Time", "Argentina Daylight Time",
- "America/Buenos_Aires"
- }, /* (GMT-03:00) Buenos Aires */
- {
- "Armenian Standard Time", "Armenian Daylight Time",
- "Asia/Yerevan"
- }, /* (GMT+04:00) Yerevan */
- {
- "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 */
- {
- "Azerbaijan Standard Time", "Azerbaijan Daylight Time",
- "Asia/Baku"
- }, /* (GMT+04:00) Baku */
- {
- "Azores Standard Time", "Azores Daylight Time",
- "Atlantic/Azores"
- }, /* (GMT-01:00) Azores */
- {
- "Bangladesh Standard Time", "Bangladesh Daylight Time",
- "Asia/Dhaka"
- }, /* (GMT+06:00) Dhaka */
- {
- "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 Brazilian Standard Time", "Central Brazilian Daylight Time",
- "America/Cuiaba"
- }, /* (GMT-04:00) Cuiaba */
- {
- "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) */
- {
- "Central Standard Time (Mexico)", "Central Daylight Time (Mexico)",
- "America/Mexico_City"
- }, /* (GMT-06:00) Guadalajara, Mexico City,
- * Monterrey - New */
- {
- "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 */
- {
- "Georgian Standard Time", "Georgian Daylight Time",
- "Asia/Tbilisi"
- }, /* (GMT+03:00) Tbilisi */
- {
- "GMT Standard Time", "GMT Daylight Time",
- "Europe/London"
- }, /* (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 */
- {
- "Jordan Standard Time", "Jordan Daylight Time",
- "Asia/Amman"
- }, /* (GMT+02:00) Amman */
- {
- "Kamchatka Standard Time", "Kamchatka Daylight Time",
- "Asia/Kamchatka"
- }, /* (GMT+12:00) Petropavlovsk-Kamchatsky */
- {
- "Korea Standard Time", "Korea Daylight Time",
- "Asia/Seoul"
- }, /* (GMT+09:00) Seoul */
- {
- "Mauritius Standard Time", "Mauritius Daylight Time",
- "Indian/Mauritius"
- }, /* (GMT+04:00) Port Louis */
- {
- "Mexico Standard Time", "Mexico Daylight Time",
- "America/Mexico_City"
- }, /* (GMT-06:00) Guadalajara, Mexico City,
- * Monterrey */
- {
- "Mexico Standard Time 2", "Mexico Daylight Time 2",
- "America/Chihuahua"
- }, /* (GMT-07:00) Chihuahua, La Paz, Mazatlan */
- {
- "Mid-Atlantic Standard Time", "Mid-Atlantic Daylight Time",
- "Atlantic/South_Georgia"
- }, /* (GMT-02:00) Mid-Atlantic */
- {
- "Middle East Standard Time", "Middle East Daylight Time",
- "Asia/Beirut"
- }, /* (GMT+02:00) Beirut */
- {
- "Montevideo Standard Time", "Montevideo Daylight Time",
- "America/Montevideo"
- }, /* (GMT-03:00) Montevideo */
- {
- "Morocco Standard Time", "Morocco Daylight Time",
- "Africa/Casablanca"
- }, /* (GMT) Casablanca */
- {
- "Mountain Standard Time", "Mountain Daylight Time",
- "US/Mountain"
- }, /* (GMT-07:00) Mountain Time (US & Canada) */
- {
- "Mountain Standard Time (Mexico)", "Mountain Daylight Time (Mexico)",
- "America/Chihuahua"
- }, /* (GMT-07:00) Chihuahua, La Paz, Mazatlan -
- * New */
- {
- "Myanmar Standard Time", "Myanmar Daylight Time",
- "Asia/Rangoon"
- }, /* (GMT+06:30) Rangoon */
- {
- "N. Central Asia Standard Time", "N. Central Asia Daylight Time",
- "Asia/Novosibirsk"
- }, /* (GMT+06:00) Novosibirsk */
- {
- "Namibia Standard Time", "Namibia Daylight Time",
- "Africa/Windhoek"
- }, /* (GMT+02:00) Windhoek */
- {
- "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 */
- {
- "Pacific Standard Time (Mexico)", "Pacific Daylight Time (Mexico)",
- "America/Tijuana"
- }, /* (GMT-08:00) Tijuana, Baja California */
- {
- "Pakistan Standard Time", "Pakistan Daylight Time",
- "Asia/Karachi"
- }, /* (GMT+05:00) Islamabad, Karachi */
- {
- "Paraguay Standard Time", "Paraguay Daylight Time",
- "America/Asuncion"
- }, /* (GMT-04:00) Asuncion */
- {
- "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 */
- {
- "Ulaanbaatar Standard Time", "Ulaanbaatar Daylight Time",
- "Asia/Ulaanbaatar",
- }, /* (GMT+08:00) Ulaanbaatar */
- {
- "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 */
- {
- "Coordinated Universal Time", "Coordinated Universal Time",
- "UTC"
- }, /* (GMT) Coordinated Universal Time */
- {
- "UTC+12", "UTC+12",
- "Etc/GMT+12"
- }, /* (GMT+12:00) Coordinated Universal Time+12 */
- {
- "UTC-02", "UTC-02",
- "Etc/GMT-02"
- }, /* (GMT-02:00) Coordinated Universal Time-02 */
- {
- "UTC-11", "UTC-11",
- "Etc/GMT-11"
- }, /* (GMT-11:00) Coordinated Universal Time-11 */
- {
- "Venezuela Standard Time", "Venezuela Daylight Time",
- "America/Caracas",
- }, /* (GMT-04:30) Caracas */
- {
- "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 */
-#ifdef NOT_USED
- /* Could not find a match for this one (just a guess). Excluded for now. */
- {
- "W. Central Africa Standard Time", "W. Central Africa Daylight Time",
- "WAT"
- }, /* (GMT+01:00) West Central Africa */
-#endif
- {
- "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];
- char localtzname[256];
- time_t t = time(NULL);
- struct tm *tm = localtime(&t);
- HKEY rootKey;
- int idx;
-
- if (!tm)
- {
- ereport(LOG,
- (errmsg("could not identify system time zone: localtime() failed"),
- errdetail("The PostgreSQL time zone will be set to \"%s\".",
- "GMT"),
- errhint("You can specify the correct timezone in postgresql.conf.")));
- return NULL; /* go to GMT */
- }
-
- 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 system time zone \"%s\"",
- win32_tzmap[i].pgtzname, tzname);
- return win32_tzmap[i].pgtzname;
- }
- }
-
- /*
- * Localized Windows versions return localized names for the timezone.
- * Scan the registry to find the English name, and then try matching
- * against our table again.
- */
- memset(localtzname, 0, sizeof(localtzname));
- if (RegOpenKeyEx(HKEY_LOCAL_MACHINE,
- "SOFTWARE\\Microsoft\\Windows NT\\CurrentVersion\\Time Zones",
- 0,
- KEY_READ,
- &rootKey) != ERROR_SUCCESS)
- {
- ereport(LOG,
- (errmsg("could not open registry key to identify system time zone: error code %lu",
- GetLastError()),
- errdetail("The PostgreSQL time zone will be set to \"%s\".",
- "GMT"),
- errhint("You can specify the correct timezone in postgresql.conf.")));
- return NULL; /* go to GMT */
- }
-
- for (idx = 0;; idx++)
- {
- char keyname[256];
- char zonename[256];
- DWORD namesize;
- FILETIME lastwrite;
- HKEY key;
- LONG r;
-
- memset(keyname, 0, sizeof(keyname));
- namesize = sizeof(keyname);
- if ((r = RegEnumKeyEx(rootKey,
- idx,
- keyname,
- &namesize,
- NULL,
- NULL,
- NULL,
- &lastwrite)) != ERROR_SUCCESS)
- {
- if (r == ERROR_NO_MORE_ITEMS)
- break;
- ereport(LOG,
- (errmsg_internal("could not enumerate registry subkeys to identify system time zone: %d", (int) r)));
- break;
- }
-
- if ((r = RegOpenKeyEx(rootKey, keyname, 0, KEY_READ, &key)) != ERROR_SUCCESS)
- {
- ereport(LOG,
- (errmsg_internal("could not open registry subkey to identify system time zone: %d", (int) r)));
- break;
- }
-
- memset(zonename, 0, sizeof(zonename));
- namesize = sizeof(zonename);
- if ((r = RegQueryValueEx(key, "Std", NULL, NULL, (unsigned char *) zonename, &namesize)) != ERROR_SUCCESS)
- {
- ereport(LOG,
- (errmsg_internal("could not query value for key \"std\" to identify system time zone \"%s\": %d",
- keyname, (int) r)));
- RegCloseKey(key);
- continue; /* Proceed to look at the next timezone */
- }
- if (strcmp(tzname, zonename) == 0)
- {
- /* Matched zone */
- strcpy(localtzname, keyname);
- RegCloseKey(key);
- break;
- }
- memset(zonename, 0, sizeof(zonename));
- namesize = sizeof(zonename);
- if ((r = RegQueryValueEx(key, "Dlt", NULL, NULL, (unsigned char *) zonename, &namesize)) != ERROR_SUCCESS)
- {
- ereport(LOG,
- (errmsg_internal("could not query value for key \"dlt\" to identify system time zone \"%s\": %d",
- keyname, (int) r)));
- RegCloseKey(key);
- continue; /* Proceed to look at the next timezone */
- }
- if (strcmp(tzname, zonename) == 0)
- {
- /* Matched DST zone */
- strcpy(localtzname, keyname);
- RegCloseKey(key);
- break;
- }
-
- RegCloseKey(key);
- }
-
- RegCloseKey(rootKey);
-
- if (localtzname[0])
- {
- /* Found a localized name, so scan for that one too */
- for (i = 0; win32_tzmap[i].stdname != NULL; i++)
- {
- if (strcmp(localtzname, win32_tzmap[i].stdname) == 0 ||
- strcmp(localtzname, win32_tzmap[i].dstname) == 0)
- {
- elog(DEBUG4, "TZ \"%s\" matches localized system time zone \"%s\" (\"%s\")",
- win32_tzmap[i].pgtzname, tzname, localtzname);
- return win32_tzmap[i].pgtzname;
- }
- }
- }
-
- ereport(LOG,
- (errmsg("could not find a match for system time zone \"%s\"",
- tzname),
- errdetail("The PostgreSQL time zone will be set to \"%s\".",
- "GMT"),
- errhint("You can specify the correct timezone in postgresql.conf.")));
- return NULL; /* go to GMT */
-}
-#endif /* WIN32 */
-
-
-
/*
* We keep loaded timezones in a hashtable so we don't have to
* load and parse the TZ definition file every time one is selected.
/*
* Load a timezone from file or from cache.
* Does not verify that the timezone is acceptable!
+ *
+ * "GMT" is always interpreted as the tzparse() definition, without attempting
+ * to load a definition from the filesystem. This has a number of benefits:
+ * 1. It's guaranteed to succeed, so we don't have the failure mode wherein
+ * the bootstrap default timezone setting doesn't work (as could happen if
+ * the OS attempts to supply a leap-second-aware version of "GMT").
+ * 2. Because we aren't accessing the filesystem, we can safely initialize
+ * the "GMT" zone definition before my_exec_path is known.
+ * 3. It's quick enough that we don't waste much time when the bootstrap
+ * default timezone setting is later overridden from postgresql.conf.
*/
-struct pg_tz *
+pg_tz *
pg_tzset(const char *name)
{
pg_tz_cache *tzp;
return &tzp->tz;
}
- if (tzload(uppername, canonname, &tzstate, TRUE) != 0)
+ /*
+ * "GMT" is always sent to tzparse(), as per discussion above.
+ */
+ if (strcmp(uppername, "GMT") == 0)
+ {
+ if (tzparse(uppername, &tzstate, TRUE) != 0)
+ {
+ /* This really, really should not happen ... */
+ elog(ERROR, "could not initialize GMT time zone");
+ }
+ /* Use uppercase name as canonical */
+ strcpy(canonname, uppername);
+ }
+ else if (tzload(uppername, canonname, &tzstate, TRUE) != 0)
{
if (uppername[0] == ':' || tzparse(uppername, &tzstate, FALSE) != 0)
{
}
-/*
- * Check whether timezone is acceptable.
- *
- * What we are doing here is checking for leap-second-aware timekeeping.
- * We need to reject such TZ settings because they'll wreak havoc with our
- * date/time arithmetic.
- *
- * NB: this must NOT ereport(ERROR). The caller must get control back so that
- * it can restore the old value of TZ if we don't like the new one.
- */
-bool
-tz_acceptable(pg_tz *tz)
-{
- struct pg_tm *tt;
- pg_time_t time2000;
-
- /*
- * To detect leap-second timekeeping, run pg_localtime for what should be
- * GMT midnight, 2000-01-01. Insist that the tm_sec value be zero; any
- * other result has to be due to leap seconds.
- */
- time2000 = (POSTGRES_EPOCH_JDATE - UNIX_EPOCH_JDATE) * SECS_PER_DAY;
- tt = pg_localtime(&time2000, tz);
- if (!tt || tt->tm_sec != 0)
- return false;
-
- return true;
-}
-
-
-/*
- * Get a pg_tz struct for the given timezone name. Returns NULL if name
- * is invalid or not an "acceptable" zone.
- */
-static pg_tz *
-get_pg_tz_for_zone(const char *tzname)
-{
- pg_tz *tz;
-
- if (!tzname || !tzname[0])
- return NULL;
-
- tz = pg_tzset(tzname);
- if (!tz)
- return NULL;
-
- if (!tz_acceptable(tz))
- return NULL;
-
- return tz;
-}
-
-/*
- * Identify a suitable default timezone setting based on the environment.
- *
- * We first look to the TZ environment variable. If not found or not
- * recognized by our own code, we see if we can identify the timezone
- * from the behavior of the system timezone library. When all else fails,
- * fall back to GMT.
- */
-static pg_tz *
-select_default_timezone(void)
-{
- pg_tz *def_tz;
-
- def_tz = get_pg_tz_for_zone(getenv("TZ"));
- if (def_tz)
- return def_tz;
-
- def_tz = get_pg_tz_for_zone(identify_system_timezone());
- if (def_tz)
- return def_tz;
-
- def_tz = get_pg_tz_for_zone("GMT");
- if (def_tz)
- return def_tz;
-
- ereport(FATAL,
- (errmsg("could not select a suitable default time zone"),
- errdetail("It appears that your GMT time zone uses leap seconds. PostgreSQL does not support leap seconds.")));
- return NULL; /* keep compiler quiet */
-}
-
-
-/*
- * Pre-initialize timezone library
- *
- * This is called before GUC variable initialization begins. Its purpose
- * is to ensure that elog.c has a pgtz variable available to format timestamps
- * with, in case log_line_prefix is set to a value requiring that. We cannot
- * set log_timezone yet.
- */
-void
-pg_timezone_pre_initialize(void)
-{
- /*
- * We can't use tzload() because we may not know where PGSHAREDIR is (in
- * particular this is true in an EXEC_BACKEND subprocess). Since this
- * timezone variable will only be used for emergency fallback purposes, it
- * seems OK to just use the "lastditch" case provided by tzparse().
- */
- if (tzparse("GMT", &gmt_timezone_data.state, TRUE) != 0)
- elog(FATAL, "could not initialize GMT time zone");
- strcpy(gmt_timezone_data.TZname, "GMT");
- gmt_timezone = &gmt_timezone_data;
-}
-
/*
* Initialize timezone library
*
- * This is called after initial loading of postgresql.conf. If no TimeZone
- * setting was found therein, we try to derive one from the environment.
- * Likewise for log_timezone.
- *
- * Note: this is also called from ProcessConfigFile, to re-establish valid
- * GUC settings if the GUCs have been reset to default following their
- * removal from postgresql.conf.
+ * This is called before GUC variable initialization begins. Its purpose
+ * is to ensure that log_timezone has a valid value before any logging GUC
+ * variables could become set to values that require elog.c to provide
+ * timestamps (e.g., log_line_prefix). We may as well initialize
+ * session_timestamp to something valid, too.
*/
void
pg_timezone_initialize(void)
{
- pg_tz *def_tz = NULL;
-
- /*
- * Make sure that session_timezone and log_timezone are set.
- * (session_timezone could still be NULL even if a timezone value was set
- * in postgresql.conf, if that setting was interval-based rather than
- * timezone-based.)
- */
- if (!session_timezone)
- {
- def_tz = select_default_timezone();
- session_timezone = def_tz;
- }
- if (!log_timezone)
- {
- /* Don't duplicate work */
- if (!def_tz)
- def_tz = select_default_timezone();
- log_timezone = def_tz;
- }
-
/*
- * Now, set the timezone and log_timezone GUCs if they're still default.
- * (This will redundantly call pg_tzset().)
- *
- * We choose to label these values PGC_S_ENV_VAR, rather than
- * PGC_S_DYNAMIC_DEFAULT which would be functionally equivalent, because
- * they came either from getenv("TZ") or from libc behavior that's
- * determined by process environment of some kind.
- *
- * Note: in the case where a setting has just been removed from
- * postgresql.conf, this code will not do what you might expect, namely
- * call select_default_timezone() and install that value as the setting.
- * Rather, the previously active setting --- typically the one from
- * postgresql.conf --- will be reinstalled, relabeled as PGC_S_ENV_VAR. If
- * we did try to install the "correct" default value, the effect would be
- * that each postmaster child would independently run an extremely
- * expensive search of the timezone database, bringing the database to its
- * knees for possibly multiple seconds. This is so unpleasant, and could
- * so easily be triggered quite unintentionally, that it seems better to
- * violate the principle of least astonishment.
+ * We may not yet know where PGSHAREDIR is (in particular this is true in
+ * an EXEC_BACKEND subprocess). So use "GMT", which pg_tzset forces to
+ * be interpreted without reference to the filesystem. This corresponds
+ * to the bootstrap default for these variables in guc.c, although in
+ * principle it could be different.
*/
- if (GetConfigOptionResetString("timezone") == NULL)
- SetConfigOption("timezone", pg_get_timezone_name(session_timezone),
- PGC_POSTMASTER, PGC_S_ENV_VAR);
-
- if (GetConfigOptionResetString("log_timezone") == NULL)
- SetConfigOption("log_timezone", pg_get_timezone_name(log_timezone),
- PGC_POSTMASTER, PGC_S_ENV_VAR);
+ session_timezone = pg_tzset("GMT");
+ log_timezone = session_timezone;
}
continue;
}
- if (!tz_acceptable(&dir->tz))
+ if (!pg_tz_acceptable(&dir->tz))
{
/* Ignore leap-second zones */
continue;
projects / postgresql / commitdiff