/*
* 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;
}
/*
* Set the global timezone. Verify that it's acceptable first.
*/
static bool
set_global_timezone(const char *tzname)
{
pg_tz *tznew;
if (!tzname || !tzname[0])
return false;
tznew = pg_tzset(tzname);
if (!tznew)
return false;
if (!tz_acceptable(tznew))
return false;
global_timezone = tznew;
return true;
}
/*
* 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;
}
pg_tz*
pg_tzenumerate_next(pg_tzenum *dir)
{
while (dir->depth >= 0) {
struct dirent *direntry;
char fullname[MAX_PG_PATH];
struct stat statbuf;
direntry = read_dir(dir->dirdesc[dir->depth], dir->dirname[dir->depth]);
if (!direntry) {
/* End of this directory */
free_dir(dir->dirdesc[dir->depth]);
pfree(dir->dirname[dir->depth]);
dir->depth--;
continue;
}
if (direntry->d_name[0] == '.')
continue;
snprintf(fullname, MAX_PG_PATH, "%s/%s", dir->dirname[dir->depth], direntry->d_name);
if (stat(fullname, &statbuf) != 0)
ereport(ERROR, (
errcode_file_access(),
errmsg("could not stat \"%s\": %m", fullname)));
if (S_ISDIR(statbuf.st_mode)) {
/* Step into the subdirectory */
if (dir->depth >= MAX_TZDIR_DEPTH - 1)
ereport(ERROR, (
errmsg_internal("timezone directory stack overflow")));
dir->depth++;
dir->dirname[dir->depth] = pstrdup(fullname);
dir->dirdesc[dir->depth] = alloc_dir(fullname);
if (!dir->dirdesc[dir->depth])
ereport(ERROR, (
errcode_file_access(),
errmsg("could not open directory \"%s\": %m",
fullname)));
/* Start over reading in the new directory */
continue;
}
/*
* Load this timezone using tzload() not pg_tzset(), so we don't fill
* the cache
*/
if (tzload(fullname + dir->baselen, dir->tz.TZname, &dir->tz.state, TRUE) != 0) {
/* Zone could not be loaded, ignore it */
continue;
}
if (!tz_acceptable(&dir->tz)) {
/* Ignore leap-second zones */
continue;
}
/* Timezone loaded OK. */
return &dir->tz;
}
/* Nothing more found */
return NULL;
}
