Revert "Optimize various aggregate deserialization functions"

This reverts commit 608fd19.

On 2nd thoughts, the StringInfo API requires that strings are NUL
terminated and pointing directly to the data in a bytea Datum isn't NUL
terminated.

Discussion: https://postgr.es/m/CAApHDvorfO3iBZ=xpiZvp3uHtJVLyFaPBSvcAhAq2HPLnaNSwQ@mail.gmail.com

Author: david-rowley

src/backend/utils/adt/array_userfuncs.c

@@ -723,13 +723,12 @@ array_agg_deserialize(PG_FUNCTION_ARGS)
 	sstate = PG_GETARG_BYTEA_PP(0);
 
 	/*
-	 * Fake up a StringInfo pointing to the bytea's value so we can "receive"
-	 * the serialized aggregate state value.
+	 * Copy the bytea into a StringInfo so that we can "receive" it using the
+	 * standard recv-function infrastructure.
 	 */
-	buf.data = VARDATA_ANY(sstate);
-	buf.len = VARSIZE_ANY_EXHDR(sstate);
-	buf.maxlen = 0;
-	buf.cursor = 0;
+	initStringInfo(&buf);
+	appendBinaryStringInfo(&buf,
+						   VARDATA_ANY(sstate), VARSIZE_ANY_EXHDR(sstate));
 
 	/* element_type */
 	element_type = pq_getmsgint(&buf, 4);
@@ -826,6 +825,7 @@ array_agg_deserialize(PG_FUNCTION_ARGS)
 	}
 
 	pq_getmsgend(&buf);
+	pfree(buf.data);
 
 	PG_RETURN_POINTER(result);
 }
@@ -1134,13 +1134,12 @@ array_agg_array_deserialize(PG_FUNCTION_ARGS)
 	sstate = PG_GETARG_BYTEA_PP(0);
 
 	/*
-	 * Fake up a StringInfo pointing to the bytea's value so we can "receive"
-	 * the serialized aggregate state value.
+	 * Copy the bytea into a StringInfo so that we can "receive" it using the
+	 * standard recv-function infrastructure.
 	 */
-	buf.data = VARDATA_ANY(sstate);
-	buf.len = VARSIZE_ANY_EXHDR(sstate);
-	buf.maxlen = 0;
-	buf.cursor = 0;
+	initStringInfo(&buf);
+	appendBinaryStringInfo(&buf,
+						   VARDATA_ANY(sstate), VARSIZE_ANY_EXHDR(sstate));
 
 	/* element_type */
 	element_type = pq_getmsgint(&buf, 4);
@@ -1198,6 +1197,7 @@ array_agg_array_deserialize(PG_FUNCTION_ARGS)
 	memcpy(result->lbs, temp, sizeof(result->lbs));
 
 	pq_getmsgend(&buf);
+	pfree(buf.data);
 
 	PG_RETURN_POINTER(result);
 }

src/backend/utils/adt/numeric.c

@@ -5190,13 +5190,12 @@ numeric_avg_deserialize(PG_FUNCTION_ARGS)
 	init_var(&tmp_var);
 
 	/*
-	 * Fake up a StringInfo pointing to the bytea's value so we can "receive"
-	 * the serialized aggregate state value.
+	 * Copy the bytea into a StringInfo so that we can "receive" it using the
+	 * standard recv-function infrastructure.
 	 */
-	buf.data = VARDATA_ANY(sstate);
-	buf.len = VARSIZE_ANY_EXHDR(sstate);
-	buf.maxlen = 0;
-	buf.cursor = 0;
+	initStringInfo(&buf);
+	appendBinaryStringInfo(&buf,
+						   VARDATA_ANY(sstate), VARSIZE_ANY_EXHDR(sstate));
 
 	result = makeNumericAggStateCurrentContext(false);
 
@@ -5223,6 +5222,7 @@ numeric_avg_deserialize(PG_FUNCTION_ARGS)
 	result->nInfcount = pq_getmsgint64(&buf);
 
 	pq_getmsgend(&buf);
+	pfree(buf.data);
 
 	free_var(&tmp_var);
 
@@ -5306,13 +5306,12 @@ numeric_deserialize(PG_FUNCTION_ARGS)
 	init_var(&tmp_var);
 
 	/*
-	 * Fake up a StringInfo pointing to the bytea's value so we can "receive"
-	 * the serialized aggregate state value.
+	 * Copy the bytea into a StringInfo so that we can "receive" it using the
+	 * standard recv-function infrastructure.
 	 */
-	buf.data = VARDATA_ANY(sstate);
-	buf.len = VARSIZE_ANY_EXHDR(sstate);
-	buf.maxlen = 0;
-	buf.cursor = 0;
+	initStringInfo(&buf);
+	appendBinaryStringInfo(&buf,
+						   VARDATA_ANY(sstate), VARSIZE_ANY_EXHDR(sstate));
 
 	result = makeNumericAggStateCurrentContext(false);
 
@@ -5343,6 +5342,7 @@ numeric_deserialize(PG_FUNCTION_ARGS)
 	result->nInfcount = pq_getmsgint64(&buf);
 
 	pq_getmsgend(&buf);
+	pfree(buf.data);
 
 	free_var(&tmp_var);
 
@@ -5677,13 +5677,12 @@ numeric_poly_deserialize(PG_FUNCTION_ARGS)
 	init_var(&tmp_var);
 
 	/*
-	 * Fake up a StringInfo pointing to the bytea's value so we can "receive"
-	 * the serialized aggregate state value.
+	 * Copy the bytea into a StringInfo so that we can "receive" it using the
+	 * standard recv-function infrastructure.
 	 */
-	buf.data = VARDATA_ANY(sstate);
-	buf.len = VARSIZE_ANY_EXHDR(sstate);
-	buf.maxlen = 0;
-	buf.cursor = 0;
+	initStringInfo(&buf);
+	appendBinaryStringInfo(&buf,
+						   VARDATA_ANY(sstate), VARSIZE_ANY_EXHDR(sstate));
 
 	result = makePolyNumAggStateCurrentContext(false);
 
@@ -5707,6 +5706,7 @@ numeric_poly_deserialize(PG_FUNCTION_ARGS)
 #endif
 
 	pq_getmsgend(&buf);
+	pfree(buf.data);
 
 	free_var(&tmp_var);
 
@@ -5868,13 +5868,12 @@ int8_avg_deserialize(PG_FUNCTION_ARGS)
 	init_var(&tmp_var);
 
 	/*
-	 * Fake up a StringInfo pointing to the bytea's value so we can "receive"
-	 * the serialized aggregate state value.
+	 * Copy the bytea into a StringInfo so that we can "receive" it using the
+	 * standard recv-function infrastructure.
 	 */
-	buf.data = VARDATA_ANY(sstate);
-	buf.len = VARSIZE_ANY_EXHDR(sstate);
-	buf.maxlen = 0;
-	buf.cursor = 0;
+	initStringInfo(&buf);
+	appendBinaryStringInfo(&buf,
+						   VARDATA_ANY(sstate), VARSIZE_ANY_EXHDR(sstate));
 
 	result = makePolyNumAggStateCurrentContext(false);
 
@@ -5890,6 +5889,7 @@ int8_avg_deserialize(PG_FUNCTION_ARGS)
 #endif
 
 	pq_getmsgend(&buf);
+	pfree(buf.data);
 
 	free_var(&tmp_var);
 

src/backend/utils/adt/varlena.c

@@ -5289,13 +5289,12 @@ string_agg_deserialize(PG_FUNCTION_ARGS)
 	sstate = PG_GETARG_BYTEA_PP(0);
 
 	/*
-	 * Fake up a StringInfo pointing to the bytea's value so we can "receive"
-	 * the serialized aggregate state value.
+	 * Copy the bytea into a StringInfo so that we can "receive" it using the
+	 * standard recv-function infrastructure.
 	 */
-	buf.data = VARDATA_ANY(sstate);
-	buf.len = VARSIZE_ANY_EXHDR(sstate);
-	buf.maxlen = 0;
-	buf.cursor = 0;
+	initStringInfo(&buf);
+	appendBinaryStringInfo(&buf,
+						   VARDATA_ANY(sstate), VARSIZE_ANY_EXHDR(sstate));
 
 	result = makeStringAggState(fcinfo);
 
@@ -5308,6 +5307,7 @@ string_agg_deserialize(PG_FUNCTION_ARGS)
 	appendBinaryStringInfo(result, data, datalen);
 
 	pq_getmsgend(&buf);
+	pfree(buf.data);
 
 	PG_RETURN_POINTER(result);
 }