diff options
Diffstat (limited to 'src/timezone/localtime.c')
| -rw-r--r-- | src/timezone/localtime.c | 23 |
1 files changed, 22 insertions, 1 deletions
diff --git a/src/timezone/localtime.c b/src/timezone/localtime.c index 154124e49c6..a2faa82ac80 100644 --- a/src/timezone/localtime.c +++ b/src/timezone/localtime.c @@ -55,6 +55,13 @@ static const pg_time_t time_t_min = MINVAL(pg_time_t, TYPE_BIT(pg_time_t)); static const pg_time_t time_t_max = MAXVAL(pg_time_t, TYPE_BIT(pg_time_t)); /* + * We cache the result of trying to load the TZDEFRULES zone here. + * tzdefrules_loaded is 0 if not tried yet, +1 if good, -1 if failed. + */ +static struct state tzdefrules_s; +static int tzdefrules_loaded = 0; + +/* * The DST rules to use if TZ has no rules and we can't load TZDEFRULES. * We default to US rules as of 1999-08-17. * POSIX 1003.1 section 8.1.1 says that the default DST rules are @@ -942,7 +949,21 @@ tzparse(const char *name, struct state * sp, bool lastditch) charcnt = stdlen + 1; if (sizeof sp->chars < charcnt) return false; - load_ok = tzload(TZDEFRULES, NULL, sp, false) == 0; + + /* + * This bit also differs from the IANA code, which doesn't make any + * attempt to avoid repetitive loadings of the TZDEFRULES zone. + */ + if (tzdefrules_loaded == 0) + { + if (tzload(TZDEFRULES, NULL, &tzdefrules_s, false) == 0) + tzdefrules_loaded = 1; + else + tzdefrules_loaded = -1; + } + load_ok = (tzdefrules_loaded > 0); + if (load_ok) + memcpy(sp, &tzdefrules_s, sizeof(struct state)); } if (!load_ok) sp->leapcnt = 0; /* so, we're off a little */ |