From 425bf3b066825fbcf258bfaf5c0d079d12f18ff8 Mon Sep 17 00:00:00 2001
From: Alvaro Herrera <alvherre@alvh.no-ip.org>
Date: Thu, 26 Oct 2017 11:15:39 +0200
Subject: [PATCH v2 6/7] Get rid of copy_partition_key

Instead, allocate the objects in the correct context right from the
start.
---
 src/backend/utils/cache/relcache.c | 77 ++++++++------------------------------
 1 file changed, 16 insertions(+), 61 deletions(-)

diff --git a/src/backend/utils/cache/relcache.c b/src/backend/utils/cache/relcache.c
index ec3b81cd2b..8b5ca749fd 100644
--- a/src/backend/utils/cache/relcache.c
+++ b/src/backend/utils/cache/relcache.c
@@ -266,7 +266,6 @@ static Relation AllocateRelationDesc(Form_pg_class relp);
 static void RelationParseRelOptions(Relation relation, HeapTuple tuple);
 static void RelationBuildTupleDesc(Relation relation);
 static void RelationBuildPartitionKey(Relation relation);
-static PartitionKey copy_partition_key(PartitionKey fromkey);
 static Relation RelationBuildDesc(Oid targetRelId, bool insertIt);
 static void RelationInitPhysicalAddr(Relation relation);
 static void load_critical_index(Oid indexoid, Oid heapoid);
@@ -853,6 +852,11 @@ RelationBuildPartitionKey(Relation relation)
 	if (!HeapTupleIsValid(tuple))
 		return;
 
+	partkeycxt = AllocSetContextCreate(CacheMemoryContext,
+									   RelationGetRelationName(relation),
+									   ALLOCSET_SMALL_SIZES);
+	oldcxt = MemoryContextSwitchTo(partkeycxt);
+
 	key = (PartitionKey) palloc0(sizeof(PartitionKeyData));
 
 	/* Fixed-length attributes */
@@ -860,6 +864,8 @@ RelationBuildPartitionKey(Relation relation)
 	key->strategy = form->partstrat;
 	key->partnatts = form->partnatts;
 
+	PG_TRY();
+	{
 	/*
 	 * We can rely on the first variable-length attribute being mapped to the
 	 * relevant field of the catalog's C struct, because all previous
@@ -983,72 +989,21 @@ RelationBuildPartitionKey(Relation relation)
 	}
 
 	ReleaseSysCache(tuple);
+	}
+	PG_CATCH();
+	{
+		MemoryContextDelete(partkeycxt);
+		PG_RE_THROW();
+	}
+	PG_END_TRY();
 
-	/* Success --- now copy to the cache memory */
-	partkeycxt = AllocSetContextCreate(CacheMemoryContext,
-									   RelationGetRelationName(relation),
-									   ALLOCSET_SMALL_SIZES);
+	/* Success --- make the relcache point to the newly constructed key */
 	relation->rd_partkeycxt = partkeycxt;
-	oldcxt = MemoryContextSwitchTo(relation->rd_partkeycxt);
-	relation->rd_partkey = copy_partition_key(key);
+	relation->rd_partkey = key;
 	MemoryContextSwitchTo(oldcxt);
 }
 
 /*
- * copy_partition_key
- *
- * The copy is allocated in the current memory context.
- */
-static PartitionKey
-copy_partition_key(PartitionKey fromkey)
-{
-	PartitionKey newkey;
-	int			n;
-
-	newkey = (PartitionKey) palloc(sizeof(PartitionKeyData));
-
-	newkey->strategy = fromkey->strategy;
-	newkey->partnatts = n = fromkey->partnatts;
-
-	newkey->partattrs = (AttrNumber *) palloc(n * sizeof(AttrNumber));
-	memcpy(newkey->partattrs, fromkey->partattrs, n * sizeof(AttrNumber));
-
-	newkey->partexprs = copyObject(fromkey->partexprs);
-
-	newkey->partopfamily = (Oid *) palloc(n * sizeof(Oid));
-	memcpy(newkey->partopfamily, fromkey->partopfamily, n * sizeof(Oid));
-
-	newkey->partopcintype = (Oid *) palloc(n * sizeof(Oid));
-	memcpy(newkey->partopcintype, fromkey->partopcintype, n * sizeof(Oid));
-
-	newkey->partsupfunc = (FmgrInfo *) palloc(n * sizeof(FmgrInfo));
-	memcpy(newkey->partsupfunc, fromkey->partsupfunc, n * sizeof(FmgrInfo));
-
-	newkey->partcollation = (Oid *) palloc(n * sizeof(Oid));
-	memcpy(newkey->partcollation, fromkey->partcollation, n * sizeof(Oid));
-
-	newkey->parttypid = (Oid *) palloc(n * sizeof(Oid));
-	memcpy(newkey->parttypid, fromkey->parttypid, n * sizeof(Oid));
-
-	newkey->parttypmod = (int32 *) palloc(n * sizeof(int32));
-	memcpy(newkey->parttypmod, fromkey->parttypmod, n * sizeof(int32));
-
-	newkey->parttyplen = (int16 *) palloc(n * sizeof(int16));
-	memcpy(newkey->parttyplen, fromkey->parttyplen, n * sizeof(int16));
-
-	newkey->parttypbyval = (bool *) palloc(n * sizeof(bool));
-	memcpy(newkey->parttypbyval, fromkey->parttypbyval, n * sizeof(bool));
-
-	newkey->parttypalign = (char *) palloc(n * sizeof(bool));
-	memcpy(newkey->parttypalign, fromkey->parttypalign, n * sizeof(char));
-
-	newkey->parttypcoll = (Oid *) palloc(n * sizeof(Oid));
-	memcpy(newkey->parttypcoll, fromkey->parttypcoll, n * sizeof(Oid));
-
-	return newkey;
-}
-
-/*
  *		equalRuleLocks
  *
  *		Determine whether two RuleLocks are equivalent
-- 
2.11.0