PGPRO-2440: Use destination's context to add into the hash table

Author: za-arthur

pg_variables.c

@@ -1582,36 +1582,24 @@ createVariableInternal(Package *package, text *name, Oid typid,
 static void
 copyValue(VarState *src, VarState *dest, Variable *destVar)
 {
-	MemoryContext oldcxt,
-				destctx;
+	MemoryContext oldcxt;
 
-	destctx = destVar->package->hctxTransact;
-	oldcxt = MemoryContextSwitchTo(destctx);
+	oldcxt = MemoryContextSwitchTo(destVar->package->hctxTransact);
 
 	if (destVar->typid == RECORDOID)
 		/* copy record value */
 	{
-		bool		found;
-		HASH_SEQ_STATUS *rstat;
-		HashRecordEntry *item_prev,
-				   *item_new;
+		HASH_SEQ_STATUS rstat;
+		HashRecordEntry *item_src;
 		RecordVar  *record_src = &src->value.record;
 		RecordVar  *record_dest = &dest->value.record;
 
 		init_record(record_dest, record_src->tupdesc, destVar);
 
 		/* Copy previous history entry into the new one */
-		rstat = (HASH_SEQ_STATUS *) palloc0(sizeof(HASH_SEQ_STATUS));
-		hash_seq_init(rstat, record_src->rhash);
-		while ((item_prev = (HashRecordEntry *) hash_seq_search(rstat)) != NULL)
-		{
-			HashRecordKey k;
-
-			k = item_prev->key;
-			item_new = (HashRecordEntry *) hash_search(record_dest->rhash, &k,
-													   HASH_ENTER, &found);
-			item_new->tuple = heap_copytuple(item_prev->tuple);
-		}
+		hash_seq_init(&rstat, record_src->rhash);
+		while ((item_src = (HashRecordEntry *) hash_seq_search(&rstat)) != NULL)
+			copy_record(record_dest, item_src->tuple, destVar);
 	}
 	else
 		/* copy scalar value */

pg_variables.h

@@ -151,6 +151,8 @@ typedef struct ChangesStackNode
 extern void init_record(RecordVar *record, TupleDesc tupdesc, Variable *variable);
 extern void check_attributes(Variable *variable, TupleDesc tupdesc);
 extern void check_record_key(Variable *variable, Oid typid);
+extern void copy_record(RecordVar *dest_record, HeapTuple src_tuple,
+						Variable *variable);
 
 extern void insert_record(Variable *variable, HeapTupleHeader tupleHeader);
 extern bool update_record(Variable *variable, HeapTupleHeader tupleHeader);

pg_variables_record.c

@@ -153,6 +153,47 @@ init_record(RecordVar *record, TupleDesc tupdesc, Variable *variable)
 	MemoryContextSwitchTo(oldcxt);
 }
 
+/*
+ * Copy record using src_tuple.
+ */
+void
+copy_record(RecordVar *dest_record, HeapTuple src_tuple, Variable *variable)
+{
+	HeapTuple	tuple;
+	Datum		value;
+	bool		isnull;
+	HashRecordKey k;
+	HashRecordEntry *item;
+	bool		found;
+	MemoryContext oldcxt;
+
+	oldcxt = MemoryContextSwitchTo(dest_record->hctx);
+
+	/* Inserting a new record into dest_record */
+	tuple = heap_copytuple(src_tuple);
+	value = fastgetattr(tuple, 1, dest_record->tupdesc, &isnull);
+
+	k.value = value;
+	k.is_null = isnull;
+	k.hash_proc = &dest_record->hash_proc;
+	k.cmp_proc = &dest_record->cmp_proc;
+
+	item = (HashRecordEntry *) hash_search(dest_record->rhash, &k,
+										   HASH_ENTER, &found);
+	if (found)
+	{
+		heap_freetuple(tuple);
+		MemoryContextSwitchTo(oldcxt);
+		ereport(ERROR,
+				(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+				 errmsg("there is a record in the variable \"%s\" with same "
+						"key", GetName(variable))));
+	}
+	item->tuple = tuple;
+
+	MemoryContextSwitchTo(oldcxt);
+}
+
 /*
  * New record structure should be the same as the first record.
  */