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Simplify SRFs using materialize mode in contrib/ modules

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9e98583 introduced a helper to centralize building their needed state
(tuplestore, tuple descriptors, etc.), checking for any errors.  This
commit updates all places of contrib/ that can be switched to use
SetSingleFuncCall() as a drop-in replacement, resulting in the removal
of a lot of boilerplate code in all the modules updated by this commit.

Per analysis, some places remain as they are:
- pg_logdir_ls() in adminpack/ uses historically TYPEFUNC_RECORD as
return type, and I suspect that changing it may cause issues at run-time
with some of its past versions, down to 1.0.
- dblink/ uses a wrapper function doing exactly the work of
SetSingleFuncCall().  Here the switch should be possible, but rather
invasive so it does not seem the extra backpatch maintenance cost.
- tablefunc/, similarly, uses multiple helper functions with portions of
SetSingleFuncCall() spread across the code paths of this module.

Author: Melanie Plageman
Discussion: https://postgr.es/m/CAAKRu_bvDPJoL9mH6eYwvBpPtTGQwbDzfJbCM-OjkSZDu5yTPg@mail.gmail.com
This commit is contained in:
Michael Paquier
2022-03-08 10:12:22 +09:00
parent d5ed9da41d
commit 5b81703787
8 changed files with 32 additions and 301 deletions
Download Patch File Download Diff File Expand all files Collapse all files

34
contrib/pgrowlocks/pgrowlocks.c
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@ -66,42 +66,16 @@ pgrowlocks(PG_FUNCTION_ARGS)
{
text *relname = PG_GETARG_TEXT_PP(0);
ReturnSetInfo *rsinfo = (ReturnSetInfo *) fcinfo->resultinfo;
bool randomAccess;
TupleDesc tupdesc;
Tuplestorestate *tupstore;
AttInMetadata *attinmeta;
Relation rel;
RangeVar *relrv;
TableScanDesc scan;
HeapScanDesc hscan;
HeapTuple tuple;
MemoryContext oldcontext;
AclResult aclresult;
char **values;
/* check to see if caller supports us returning a tuplestore */
if (rsinfo == NULL || !IsA(rsinfo, ReturnSetInfo))
ereport(ERROR,
(errcode(ERRCODE_FEATURE_NOT_SUPPORTED),
errmsg("set-valued function called in context that cannot accept a set")));
if (!(rsinfo->allowedModes & SFRM_Materialize))
ereport(ERROR,
(errcode(ERRCODE_SYNTAX_ERROR),
errmsg("materialize mode required, but it is not allowed in this context")));
/* The tupdesc and tuplestore must be created in ecxt_per_query_memory */
oldcontext = MemoryContextSwitchTo(rsinfo->econtext->ecxt_per_query_memory);
if (get_call_result_type(fcinfo, NULL, &tupdesc) != TYPEFUNC_COMPOSITE)
elog(ERROR, "return type must be a row type");
randomAccess = (rsinfo->allowedModes & SFRM_Materialize_Random) != 0;
tupstore = tuplestore_begin_heap(randomAccess, false, work_mem);
rsinfo->returnMode = SFRM_Materialize;
rsinfo->setResult = tupstore;
rsinfo->setDesc = tupdesc;
MemoryContextSwitchTo(oldcontext);
SetSingleFuncCall(fcinfo, 0);
/* Access the table */
relrv = makeRangeVarFromNameList(textToQualifiedNameList(relname));
@ -140,9 +114,9 @@ pgrowlocks(PG_FUNCTION_ARGS)
scan = table_beginscan(rel, GetActiveSnapshot(), 0, NULL);
hscan = (HeapScanDesc) scan;
attinmeta = TupleDescGetAttInMetadata(tupdesc);
attinmeta = TupleDescGetAttInMetadata(rsinfo->setDesc);
values = (char **) palloc(tupdesc->natts * sizeof(char *));
values = (char **) palloc(rsinfo->setDesc->natts * sizeof(char *));
while ((tuple = heap_getnext(scan, ForwardScanDirection)) != NULL)
{
@ -288,7 +262,7 @@ pgrowlocks(PG_FUNCTION_ARGS)
/* build a tuple */
tuple = BuildTupleFromCStrings(attinmeta, values);
tuplestore_puttuple(tupstore, tuple);
tuplestore_puttuple(rsinfo->setResult, tuple);
}
else
{