/*
* 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;
}
/*
* 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;
}
