0001-Add-repalloc0-and-repalloc0_array.patch

From fa611ecf7c8a7b99d37c77da66b421d2f9ebfec3 Mon Sep 17 00:00:00 2001
From: Peter Eisentraut <peter@eisentraut.org>
Date: Wed, 14 Sep 2022 06:05:46 +0200
Subject: [PATCH] Add repalloc0 and repalloc0_array

These zero out the space added by repalloc.  This is a common pattern
that is quite hairy to code by hand.
---
 src/backend/executor/nodeHash.c          |  8 ++-----
 src/backend/libpq/be-fsstubs.c           |  9 +++-----
 src/backend/optimizer/util/placeholder.c | 13 ++++-------
 src/backend/optimizer/util/relnode.c     | 29 +++++++-----------------
 src/backend/parser/parse_param.c         | 10 +++-----
 src/backend/storage/lmgr/lwlock.c        |  9 ++------
 src/backend/utils/adt/ruleutils.c        |  9 ++------
 src/backend/utils/cache/typcache.c       | 10 ++------
 src/backend/utils/mmgr/mcxt.c            | 15 ++++++++++++
 src/include/utils/palloc.h               |  2 ++
 10 files changed, 43 insertions(+), 71 deletions(-)

diff --git a/src/backend/executor/nodeHash.c b/src/backend/executor/nodeHash.c
index 77dd1dae8b..674802a4ff 100644
--- a/src/backend/executor/nodeHash.c
+++ b/src/backend/executor/nodeHash.c
@@ -940,12 +940,8 @@ ExecHashIncreaseNumBatches(HashJoinTable hashtable)
 	else
 	{
 		/* enlarge arrays and zero out added entries */
-		hashtable->innerBatchFile = repalloc_array(hashtable->innerBatchFile, BufFile *, nbatch);
-		hashtable->outerBatchFile = repalloc_array(hashtable->outerBatchFile, BufFile *, nbatch);
-		MemSet(hashtable->innerBatchFile + oldnbatch, 0,
-			   (nbatch - oldnbatch) * sizeof(BufFile *));
-		MemSet(hashtable->outerBatchFile + oldnbatch, 0,
-			   (nbatch - oldnbatch) * sizeof(BufFile *));
+		hashtable->innerBatchFile = repalloc0_array(hashtable->innerBatchFile, BufFile *, nbatch, oldnbatch);
+		hashtable->outerBatchFile = repalloc0_array(hashtable->outerBatchFile, BufFile *, nbatch, oldnbatch);
 	}
 
 	MemoryContextSwitchTo(oldcxt);
diff --git a/src/backend/libpq/be-fsstubs.c b/src/backend/libpq/be-fsstubs.c
index 3e5cada7eb..bf901a9cdc 100644
--- a/src/backend/libpq/be-fsstubs.c
+++ b/src/backend/libpq/be-fsstubs.c
@@ -696,19 +696,16 @@ newLOfd(void)
 		newsize = 64;
 		cookies = (LargeObjectDesc **)
 			MemoryContextAllocZero(fscxt, newsize * sizeof(LargeObjectDesc *));
-		cookies_size = newsize;
 	}
 	else
 	{
 		/* Double size of array */
 		i = cookies_size;
 		newsize = cookies_size * 2;
-		cookies = (LargeObjectDesc **)
-			repalloc(cookies, newsize * sizeof(LargeObjectDesc *));
-		MemSet(cookies + cookies_size, 0,
-			   (newsize - cookies_size) * sizeof(LargeObjectDesc *));
-		cookies_size = newsize;
+		cookies =
+			repalloc0_array(cookies, LargeObjectDesc *, newsize, cookies_size);
 	}
+	cookies_size = newsize;
 
 	return i;
 }
diff --git a/src/backend/optimizer/util/placeholder.c b/src/backend/optimizer/util/placeholder.c
index c7bfa293c9..e40b3a12fd 100644
--- a/src/backend/optimizer/util/placeholder.c
+++ b/src/backend/optimizer/util/placeholder.c
@@ -133,16 +133,11 @@ find_placeholder_info(PlannerInfo *root, PlaceHolderVar *phv)
 		while (phinfo->phid >= new_size)
 			new_size *= 2;
 		if (root->placeholder_array)
-		{
-			root->placeholder_array = (PlaceHolderInfo **)
-				repalloc(root->placeholder_array,
-						 sizeof(PlaceHolderInfo *) * new_size);
-			MemSet(root->placeholder_array + root->placeholder_array_size, 0,
-				   sizeof(PlaceHolderInfo *) * (new_size - root->placeholder_array_size));
-		}
+			root->placeholder_array =
+				repalloc0_array(root->placeholder_array, PlaceHolderInfo *, new_size, root->placeholder_array_size);
 		else
-			root->placeholder_array = (PlaceHolderInfo **)
-				palloc0(new_size * sizeof(PlaceHolderInfo *));
+			root->placeholder_array =
+				palloc0_array(PlaceHolderInfo *, new_size);
 		root->placeholder_array_size = new_size;
 	}
 	root->placeholder_array[phinfo->phid] = phinfo;
diff --git a/src/backend/optimizer/util/relnode.c b/src/backend/optimizer/util/relnode.c
index edcdd0a360..3ea40ff1b6 100644
--- a/src/backend/optimizer/util/relnode.c
+++ b/src/backend/optimizer/util/relnode.c
@@ -157,31 +157,18 @@ expand_planner_arrays(PlannerInfo *root, int add_size)
 
 	new_size = root->simple_rel_array_size + add_size;
 
-	root->simple_rel_array = (RelOptInfo **)
-		repalloc(root->simple_rel_array,
-				 sizeof(RelOptInfo *) * new_size);
-	MemSet(root->simple_rel_array + root->simple_rel_array_size,
-		   0, sizeof(RelOptInfo *) * add_size);
+	root->simple_rel_array =
+		repalloc0_array(root->simple_rel_array, RelOptInfo *, new_size, root->simple_rel_array_size);
 
-	root->simple_rte_array = (RangeTblEntry **)
-		repalloc(root->simple_rte_array,
-				 sizeof(RangeTblEntry *) * new_size);
-	MemSet(root->simple_rte_array + root->simple_rel_array_size,
-		   0, sizeof(RangeTblEntry *) * add_size);
+	root->simple_rte_array =
+		repalloc0_array(root->simple_rte_array, RangeTblEntry *, new_size, root->simple_rel_array_size);
 
 	if (root->append_rel_array)
-	{
-		root->append_rel_array = (AppendRelInfo **)
-			repalloc(root->append_rel_array,
-					 sizeof(AppendRelInfo *) * new_size);
-		MemSet(root->append_rel_array + root->simple_rel_array_size,
-			   0, sizeof(AppendRelInfo *) * add_size);
-	}
+		root->append_rel_array =
+			repalloc0_array(root->append_rel_array, AppendRelInfo *, new_size, root->simple_rel_array_size);
 	else
-	{
-		root->append_rel_array = (AppendRelInfo **)
-			palloc0(sizeof(AppendRelInfo *) * new_size);
-	}
+		root->append_rel_array =
+			palloc0_array(AppendRelInfo *, new_size);
 
 	root->simple_rel_array_size = new_size;
 }
diff --git a/src/backend/parser/parse_param.c b/src/backend/parser/parse_param.c
index f668abfcb3..4efec211c5 100644
--- a/src/backend/parser/parse_param.c
+++ b/src/backend/parser/parse_param.c
@@ -145,14 +145,10 @@ variable_paramref_hook(ParseState *pstate, ParamRef *pref)
 	{
 		/* Need to enlarge param array */
 		if (*parstate->paramTypes)
-			*parstate->paramTypes = (Oid *) repalloc(*parstate->paramTypes,
-													 paramno * sizeof(Oid));
+			*parstate->paramTypes = repalloc0_array(*parstate->paramTypes, Oid,
+													paramno, *parstate->numParams);
 		else
-			*parstate->paramTypes = (Oid *) palloc(paramno * sizeof(Oid));
-		/* Zero out the previously-unreferenced slots */
-		MemSet(*parstate->paramTypes + *parstate->numParams,
-			   0,
-			   (paramno - *parstate->numParams) * sizeof(Oid));
+			*parstate->paramTypes = palloc0_array(Oid, paramno);
 		*parstate->numParams = paramno;
 	}
 
diff --git a/src/backend/storage/lmgr/lwlock.c b/src/backend/storage/lmgr/lwlock.c
index 38317edaf9..a36dcf1a00 100644
--- a/src/backend/storage/lmgr/lwlock.c
+++ b/src/backend/storage/lmgr/lwlock.c
@@ -668,13 +668,8 @@ LWLockRegisterTranche(int tranche_id, const char *tranche_name)
 				MemoryContextAllocZero(TopMemoryContext,
 									   newalloc * sizeof(char *));
 		else
-		{
-			LWLockTrancheNames = (const char **)
-				repalloc(LWLockTrancheNames, newalloc * sizeof(char *));
-			memset(LWLockTrancheNames + LWLockTrancheNamesAllocated,
-				   0,
-				   (newalloc - LWLockTrancheNamesAllocated) * sizeof(char *));
-		}
+			LWLockTrancheNames =
+				repalloc0_array(LWLockTrancheNames, const char *, newalloc, LWLockTrancheNamesAllocated);
 		LWLockTrancheNamesAllocated = newalloc;
 	}
 
diff --git a/src/backend/utils/adt/ruleutils.c b/src/backend/utils/adt/ruleutils.c
index 2b7b1b0c0f..0cd63383ec 100644
--- a/src/backend/utils/adt/ruleutils.c
+++ b/src/backend/utils/adt/ruleutils.c
@@ -4855,14 +4855,9 @@ expand_colnames_array_to(deparse_columns *colinfo, int n)
 	if (n > colinfo->num_cols)
 	{
 		if (colinfo->colnames == NULL)
-			colinfo->colnames = (char **) palloc0(n * sizeof(char *));
+			colinfo->colnames = palloc0_array(char *, n);
 		else
-		{
-			colinfo->colnames = (char **) repalloc(colinfo->colnames,
-												   n * sizeof(char *));
-			memset(colinfo->colnames + colinfo->num_cols, 0,
-				   (n - colinfo->num_cols) * sizeof(char *));
-		}
+			colinfo->colnames = repalloc0_array(colinfo->colnames, char *, n, colinfo->num_cols);
 		colinfo->num_cols = n;
 	}
 }
diff --git a/src/backend/utils/cache/typcache.c b/src/backend/utils/cache/typcache.c
index 808f9ebd0d..739765cb09 100644
--- a/src/backend/utils/cache/typcache.c
+++ b/src/backend/utils/cache/typcache.c
@@ -1714,14 +1714,8 @@ ensure_record_cache_typmod_slot_exists(int32 typmod)
 	{
 		int32		newlen = pg_nextpower2_32(typmod + 1);
 
-		RecordCacheArray = (TupleDesc *) repalloc(RecordCacheArray,
-												  newlen * sizeof(TupleDesc));
-		memset(RecordCacheArray + RecordCacheArrayLen, 0,
-			   (newlen - RecordCacheArrayLen) * sizeof(TupleDesc));
-		RecordIdentifierArray = (uint64 *) repalloc(RecordIdentifierArray,
-													newlen * sizeof(uint64));
-		memset(RecordIdentifierArray + RecordCacheArrayLen, 0,
-			   (newlen - RecordCacheArrayLen) * sizeof(uint64));
+		RecordCacheArray = repalloc0_array(RecordCacheArray, TupleDesc, newlen, RecordCacheArrayLen);
+		RecordIdentifierArray = repalloc0_array(RecordIdentifierArray, uint64, newlen, RecordCacheArrayLen);
 		RecordCacheArrayLen = newlen;
 	}
 }
diff --git a/src/backend/utils/mmgr/mcxt.c b/src/backend/utils/mmgr/mcxt.c
index 115a64cfe4..027af1e5de 100644
--- a/src/backend/utils/mmgr/mcxt.c
+++ b/src/backend/utils/mmgr/mcxt.c
@@ -1297,6 +1297,21 @@ repalloc(void *pointer, Size size)
 	return ret;
 }
 
+/*
+ * repalloc
+ *		Adjust the size of a previously allocated chunk and zero out the added
+ *		space.
+ */
+void *
+repalloc0(void *pointer, Size size, Size oldsize)
+{
+	void	   *ret;
+
+	ret = repalloc(pointer, size);
+	memset((char *) ret + oldsize, 0, (size - oldsize));
+	return ret;
+}
+
 /*
  * MemoryContextAllocHuge
  *		Allocate (possibly-expansive) space within the specified context.
diff --git a/src/include/utils/palloc.h b/src/include/utils/palloc.h
index a0b62aa7b0..af7a4a2311 100644
--- a/src/include/utils/palloc.h
+++ b/src/include/utils/palloc.h
@@ -78,6 +78,7 @@ extern void *palloc(Size size);
 extern void *palloc0(Size size);
 extern void *palloc_extended(Size size, int flags);
 extern pg_nodiscard void *repalloc(void *pointer, Size size);
+extern pg_nodiscard void *repalloc0(void *pointer, Size size, Size oldsize);
 extern void pfree(void *pointer);
 
 /*
@@ -101,6 +102,7 @@ extern void pfree(void *pointer);
  * objects of type "type"
  */
 #define repalloc_array(pointer, type, count) ((type *) repalloc(pointer, sizeof(type) * (count)))
+#define repalloc0_array(pointer, type, count, oldcount) ((type *) repalloc0(pointer, sizeof(type) * (count), sizeof(type) * (oldcount)))
 
 /*
  * The result of palloc() is always word-aligned, so we can skip testing
-- 
2.37.3