From 22e3b558052aa209cba2a8fec192d76b5faef19e Mon Sep 17 00:00:00 2001 From: Michael Paquier Date: Wed, 21 Dec 2022 10:11:22 +0900 Subject: Switch some system functions to use get_call_result_type() MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit This shaves some code by replacing the combinations of CreateTemplateTupleDesc()/TupleDescInitEntry() hardcoding a mapping of the attributes listed in pg_proc.dat by get_call_result_type() to build the TupleDesc needed for the rows generated. get_call_result_type() is more expensive than the former style, but this removes some duplication with the lists of OUT parameters (pg_proc.dat and the attributes hardcoded in these code paths). This is applied to functions that are not considered as critical (aka that could be called repeatedly for monitoring purposes). Author: Bharath Rupireddy Reviewed-by: Robert Haas, Álvaro Herrera, Tom Lane, Michael Paquier Discussion: https://postgr.es/m/CALj2ACV23HW5HP5hFjd89FNS-z5X8r2jNXdMXcpN2BgTtKd87w@mail.gmail.com --- contrib/old_snapshot/time_mapping.c | 26 ++++---------------------- 1 file changed, 4 insertions(+), 22 deletions(-) (limited to 'contrib/old_snapshot/time_mapping.c') diff --git a/contrib/old_snapshot/time_mapping.c b/contrib/old_snapshot/time_mapping.c index 2d8cb742c34..aa4901fa1c4 100644 --- a/contrib/old_snapshot/time_mapping.c +++ b/contrib/old_snapshot/time_mapping.c @@ -38,7 +38,6 @@ PG_MODULE_MAGIC; PG_FUNCTION_INFO_V1(pg_old_snapshot_time_mapping); static OldSnapshotTimeMapping *GetOldSnapshotTimeMapping(void); -static TupleDesc MakeOldSnapshotTimeMappingTupleDesc(void); static HeapTuple MakeOldSnapshotTimeMappingTuple(TupleDesc tupdesc, OldSnapshotTimeMapping *mapping); @@ -54,12 +53,15 @@ pg_old_snapshot_time_mapping(PG_FUNCTION_ARGS) if (SRF_IS_FIRSTCALL()) { MemoryContext oldcontext; + TupleDesc tupdesc; funcctx = SRF_FIRSTCALL_INIT(); oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx); mapping = GetOldSnapshotTimeMapping(); funcctx->user_fctx = mapping; - funcctx->tuple_desc = MakeOldSnapshotTimeMappingTupleDesc(); + if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE) + elog(ERROR, "return type must be a row type"); + funcctx->tuple_desc = tupdesc; MemoryContextSwitchTo(oldcontext); } @@ -101,26 +103,6 @@ GetOldSnapshotTimeMapping(void) return mapping; } -/* - * Build a tuple descriptor for the pg_old_snapshot_time_mapping() SRF. - */ -static TupleDesc -MakeOldSnapshotTimeMappingTupleDesc(void) -{ - TupleDesc tupdesc; - - tupdesc = CreateTemplateTupleDesc(NUM_TIME_MAPPING_COLUMNS); - - TupleDescInitEntry(tupdesc, (AttrNumber) 1, "array_offset", - INT4OID, -1, 0); - TupleDescInitEntry(tupdesc, (AttrNumber) 2, "end_timestamp", - TIMESTAMPTZOID, -1, 0); - TupleDescInitEntry(tupdesc, (AttrNumber) 3, "newest_xmin", - XIDOID, -1, 0); - - return BlessTupleDesc(tupdesc); -} - /* * Convert one entry from the old snapshot time mapping to a HeapTuple. */ -- cgit v1.2.3