/*
* 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;
}
pg_tz *
pg_tzenumerate_next(pg_tzenum *dir)
{
while (dir->depth >= 0)
{
struct dirent *direntry;
char fullname[MAXPGPATH * 2];
struct stat statbuf;
direntry = ReadDir(dir->dirdesc[dir->depth], dir->dirname[dir->depth]);
if (!direntry)
{
/* End of this directory */
FreeDir(dir->dirdesc[dir->depth]);
pfree(dir->dirname[dir->depth]);
dir->depth--;
continue;
}
if (direntry->d_name[0] == '.')
continue;
snprintf(fullname, sizeof(fullname), "%s/%s",
dir->dirname[dir->depth], direntry->d_name);
if (stat(fullname, &statbuf) != 0)
ereport(ERROR,
(errcode_for_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] = AllocateDir(fullname);
if (!dir->dirdesc[dir->depth])
ereport(ERROR,
(errcode_for_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 (!pg_tz_acceptable(&dir->tz))
{
/* Ignore leap-second zones */
continue;
}
/* Timezone loaded OK. */
return &dir->tz;
}
/* Nothing more found */
return NULL;
}
/*
* 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;
}
