Assorted examples of expanded type-safer palloc/pg_malloc API

This adds some uses of the new palloc/pg_malloc variants here and
there as a demonstration and test.  This is kept separate from the
actual API patch, since the latter might be backpatched at some point.

Reviewed-by: Tom Lane <tgl@sss.pgh.pa.us>
Discussion: https://www.postgresql.org/message-id/flat/bb755632-2a43-d523-36f8-a1e7a389a907@enterprisedb.com

2 files changed, 14 insertions, 17 deletions

diff --git a/src/backend/access/brin/brin.c b/src/backend/access/brin/brin.c
index 69f21abfb59..dcf2d2c4b50 100644
--- a/src/backend/access/brin/brin.c
+++ b/src/backend/access/brin/brin.c
@@ -329,7 +329,7 @@ brinbeginscan(Relation r, int nkeys, int norderbys)
 
 	scan = RelationGetIndexScan(r, nkeys, norderbys);
 
-	opaque = (BrinOpaque *) palloc(sizeof(BrinOpaque));
+	opaque = palloc_object(BrinOpaque);
 	opaque->bo_rmAccess = brinRevmapInitialize(r, &opaque->bo_pagesPerRange,
 											   scan->xs_snapshot);
 	opaque->bo_bdesc = brin_build_desc(r);
@@ -394,7 +394,7 @@ bringetbitmap(IndexScanDesc scan, TIDBitmap *tbm)
 	 * don't look them up here; we do that lazily the first time we see a scan
 	 * key reference each of them.  We rely on zeroing fn_oid to InvalidOid.
 	 */
-	consistentFn = palloc0(sizeof(FmgrInfo) * bdesc->bd_tupdesc->natts);
+	consistentFn = palloc0_array(FmgrInfo, bdesc->bd_tupdesc->natts);
 
 	/*
 	 * Make room for per-attribute lists of scan keys that we'll pass to the
@@ -881,7 +881,7 @@ brinbuild(Relation heap, Relation index, IndexInfo *indexInfo)
 	/*
 	 * Return statistics
 	 */
-	result = (IndexBuildResult *) palloc(sizeof(IndexBuildResult));
+	result = palloc_object(IndexBuildResult);
 
 	result->heap_tuples = reltuples;
 	result->index_tuples = idxtuples;
@@ -925,7 +925,7 @@ brinbulkdelete(IndexVacuumInfo *info, IndexBulkDeleteResult *stats,
 {
 	/* allocate stats if first time through, else re-use existing struct */
 	if (stats == NULL)
-		stats = (IndexBulkDeleteResult *) palloc0(sizeof(IndexBulkDeleteResult));
+		stats = palloc0_object(IndexBulkDeleteResult);
 
 	return stats;
 }
@@ -944,7 +944,7 @@ brinvacuumcleanup(IndexVacuumInfo *info, IndexBulkDeleteResult *stats)
 		return stats;
 
 	if (!stats)
-		stats = (IndexBulkDeleteResult *) palloc0(sizeof(IndexBulkDeleteResult));
+		stats = palloc0_object(IndexBulkDeleteResult);
 	stats->num_pages = RelationGetNumberOfBlocks(info->index);
 	/* rest of stats is initialized by zeroing */
 
@@ -1204,7 +1204,7 @@ brin_build_desc(Relation rel)
 	 * Obtain BrinOpcInfo for each indexed column.  While at it, accumulate
 	 * the number of columns stored, since the number is opclass-defined.
 	 */
-	opcinfo = (BrinOpcInfo **) palloc(sizeof(BrinOpcInfo *) * tupdesc->natts);
+	opcinfo = palloc_array(BrinOpcInfo*, tupdesc->natts);
 	for (keyno = 0; keyno < tupdesc->natts; keyno++)
 	{
 		FmgrInfo   *opcInfoFn;
@@ -1276,7 +1276,7 @@ initialize_brin_buildstate(Relation idxRel, BrinRevmap *revmap,
 {
 	BrinBuildState *state;
 
-	state = palloc(sizeof(BrinBuildState));
+	state = palloc_object(BrinBuildState);
 
 	state->bs_irel = idxRel;
 	state->bs_numtuples = 0;
diff --git a/src/backend/access/gin/ginfast.c b/src/backend/access/gin/ginfast.c
index 6c677447a95..ab4bb67d4b4 100644
--- a/src/backend/access/gin/ginfast.c
+++ b/src/backend/access/gin/ginfast.c
@@ -505,7 +505,7 @@ ginHeapTupleFastCollect(GinState *ginstate,
 		 * resizing (since palloc likes powers of 2).
 		 */
 		collector->lentuples = pg_nextpower2_32(Max(16, nentries));
-		collector->tuples = (IndexTuple *) palloc(sizeof(IndexTuple) * collector->lentuples);
+		collector->tuples = palloc_array(IndexTuple, collector->lentuples);
 	}
 	else if (collector->lentuples < collector->ntuples + nentries)
 	{
@@ -515,8 +515,8 @@ ginHeapTupleFastCollect(GinState *ginstate,
 		 * MaxAllocSize/sizeof(IndexTuple), causing an error in repalloc.
 		 */
 		collector->lentuples = pg_nextpower2_32(collector->ntuples + nentries);
-		collector->tuples = (IndexTuple *) repalloc(collector->tuples,
-													sizeof(IndexTuple) * collector->lentuples);
+		collector->tuples = repalloc_array(collector->tuples,
+										   IndexTuple, collector->lentuples);
 	}
 
 	/*
@@ -665,9 +665,8 @@ shiftList(Relation index, Buffer metabuffer, BlockNumber newHead,
 static void
 initKeyArray(KeyArray *keys, int32 maxvalues)
 {
-	keys->keys = (Datum *) palloc(sizeof(Datum) * maxvalues);
-	keys->categories = (GinNullCategory *)
-		palloc(sizeof(GinNullCategory) * maxvalues);
+	keys->keys = palloc_array(Datum, maxvalues);
+	keys->categories = palloc_array(GinNullCategory, maxvalues);
 	keys->nvalues = 0;
 	keys->maxvalues = maxvalues;
 }
@@ -679,10 +678,8 @@ addDatum(KeyArray *keys, Datum datum, GinNullCategory category)
 	if (keys->nvalues >= keys->maxvalues)
 	{
 		keys->maxvalues *= 2;
-		keys->keys = (Datum *)
-			repalloc(keys->keys, sizeof(Datum) * keys->maxvalues);
-		keys->categories = (GinNullCategory *)
-			repalloc(keys->categories, sizeof(GinNullCategory) * keys->maxvalues);
+		keys->keys = repalloc_array(keys->keys, Datum, keys->maxvalues);
+		keys->categories = repalloc_array(keys->categories, GinNullCategory, keys->maxvalues);
 	}
 
 	keys->keys[keys->nvalues] = datum;