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Rename the recently-added pg_timezonenames view to pg_timezone_abbrevs,

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and create a new view pg_timezone_names that provides information about
the zones known in the 'zic' database.  Magnus Hagander, with some
additional work by Tom Lane.
This commit is contained in:
Tom Lane
2006-09-16 20:14:34 +00:00
parent 7ed5df437d
commit 5ff4f39c0e
9 changed files with 331 additions and 31 deletions
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125
src/backend/utils/adt/datetime.c
View File

@ -8,7 +8,7 @@
*
*
* IDENTIFICATION
* $PostgreSQL: pgsql/src/backend/utils/adt/datetime.c,v 1.170 2006/09/04 01:26:27 tgl Exp $
* $PostgreSQL: pgsql/src/backend/utils/adt/datetime.c,v 1.171 2006/09/16 20:14:33 tgl Exp $
*
*-------------------------------------------------------------------------
*/
@ -3839,21 +3839,21 @@ InstallTimeZoneAbbrevs(tzEntry *abbrevs, int n)
/*
* This set-returning function reads all the available time zone abbreviations
* and returns a set of (name, utc_offset, is_dst).
* and returns a set of (abbrev, utc_offset, is_dst).
*/
Datum
pg_timezonenames(PG_FUNCTION_ARGS)
pg_timezone_abbrevs(PG_FUNCTION_ARGS)
{
FuncCallContext *funcctx;
int *pindex;
Datum result;
Interval *resInterval;
HeapTuple tuple;
Datum values[3];
bool nulls[3];
char buffer[TOKMAXLEN + 1];
unsigned char *p;
struct pg_tm tm;
Interval *resInterval;
/* stuff done only on the first call of the function */
if (SRF_IS_FIRSTCALL())
@ -3876,11 +3876,11 @@ pg_timezonenames(PG_FUNCTION_ARGS)
funcctx->user_fctx = (void *) pindex;
/*
* build tupdesc for result tuples. This must match the
* definition of the pg_timezonenames view in system_views.sql
* build tupdesc for result tuples. This must match this function's
* pg_proc entry!
*/
tupdesc = CreateTemplateTupleDesc(3, false);
TupleDescInitEntry(tupdesc, (AttrNumber) 1, "name",
TupleDescInitEntry(tupdesc, (AttrNumber) 1, "abbrev",
TEXTOID, -1, 0);
TupleDescInitEntry(tupdesc, (AttrNumber) 2, "utc_offset",
INTERVALOID, -1, 0);
@ -3928,3 +3928,114 @@ pg_timezonenames(PG_FUNCTION_ARGS)
SRF_RETURN_NEXT(funcctx, result);
}
/*
* This set-returning function reads all the available full time zones
* and returns a set of (name, abbrev, utc_offset, is_dst).
*/
Datum
pg_timezone_names(PG_FUNCTION_ARGS)
{
MemoryContext oldcontext;
FuncCallContext *funcctx;
pg_tzenum *tzenum;
pg_tz *tz;
Datum result;
HeapTuple tuple;
Datum values[4];
bool nulls[4];
int tzoff;
struct pg_tm tm;
fsec_t fsec;
char *tzn;
Interval *resInterval;
struct pg_tm itm;
/* stuff done only on the first call of the function */
if (SRF_IS_FIRSTCALL())
{
TupleDesc tupdesc;
/* create a function context for cross-call persistence */
funcctx = SRF_FIRSTCALL_INIT();
/*
* switch to memory context appropriate for multiple function
* calls
*/
oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
/* initialize timezone scanning code */
tzenum = pg_tzenumerate_start();
funcctx->user_fctx = (void *) tzenum;
/*
* build tupdesc for result tuples. This must match this function's
* pg_proc entry!
*/
tupdesc = CreateTemplateTupleDesc(4, false);
TupleDescInitEntry(tupdesc, (AttrNumber) 1, "name",
TEXTOID, -1, 0);
TupleDescInitEntry(tupdesc, (AttrNumber) 2, "abbrev",
TEXTOID, -1, 0);
TupleDescInitEntry(tupdesc, (AttrNumber) 3, "utc_offset",
INTERVALOID, -1, 0);
TupleDescInitEntry(tupdesc, (AttrNumber) 4, "is_dst",
BOOLOID, -1, 0);
funcctx->tuple_desc = BlessTupleDesc(tupdesc);
MemoryContextSwitchTo(oldcontext);
}
/* stuff done on every call of the function */
funcctx = SRF_PERCALL_SETUP();
tzenum = (pg_tzenum *) funcctx->user_fctx;
/* search for another zone to display */
for (;;)
{
oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
tz = pg_tzenumerate_next(tzenum);
MemoryContextSwitchTo(oldcontext);
if (!tz)
{
pg_tzenumerate_end(tzenum);
funcctx->user_fctx = NULL;
SRF_RETURN_DONE(funcctx);
}
/* Convert now() to local time in this zone */
if (timestamp2tm(GetCurrentTransactionStartTimestamp(),
&tzoff, &tm, &fsec, &tzn, tz) != 0)
continue; /* ignore if conversion fails */
/* Ignore zic's rather silly "Factory" time zone */
if (tzn && strcmp(tzn, "Local time zone must be set--see zic manual page") == 0)
continue;
/* Found a displayable zone */
break;
}
MemSet(nulls, 0, sizeof(nulls));
values[0] = DirectFunctionCall1(textin,
CStringGetDatum(pg_get_timezone_name(tz)));
values[1] = DirectFunctionCall1(textin,
CStringGetDatum(tzn ? tzn : ""));
MemSet(&itm, 0, sizeof(struct pg_tm));
itm.tm_sec = -tzoff;
resInterval = (Interval *) palloc(sizeof(Interval));
tm2interval(&itm, 0, resInterval);
values[2] = IntervalPGetDatum(resInterval);
values[3] = BoolGetDatum(tm.tm_isdst > 0);
tuple = heap_form_tuple(funcctx->tuple_desc, values, nulls);
result = HeapTupleGetDatum(tuple);
SRF_RETURN_NEXT(funcctx, result);
}