Simplify and move to jsonb_utils.c clone_parse_state()

Author: Nikita Glukhov

src/backend/utils/adt/jsonb.c

@@ -65,7 +65,6 @@ static void datum_to_jsonb(Datum val, bool is_null, JsonbInState *result,
 						   bool key_scalar);
 static void add_jsonb(Datum val, bool is_null, JsonbInState *result,
 					  Oid val_type, bool key_scalar);
-static JsonbParseState *clone_parse_state(JsonbParseState *state);
 static char *JsonbToCStringWorker(StringInfo out, JsonbContainer *in, int estimated_len, bool indent);
 static void add_indent(StringInfo out, bool indent, int level);
 
@@ -1519,44 +1518,11 @@ jsonb_object_two_arg(PG_FUNCTION_ARGS)
 	PG_RETURN_POINTER(JsonbValueToJsonb(result.res));
 }
 
-
 /*
- * shallow clone of a parse state, suitable for use in aggregate
- * final functions that will only append to the values rather than
- * change them.
+ * jsonb_agg aggregate function
  */
-static JsonbParseState *
-clone_parse_state(JsonbParseState *state)
-{
-	JsonbParseState *result,
-			   *icursor,
-			   *ocursor;
-
-	if (state == NULL)
-		return NULL;
-
-	result = palloc(sizeof(JsonbParseState));
-	icursor = state;
-	ocursor = result;
-	for (;;)
-	{
-		ocursor->contVal = icursor->contVal;
-		ocursor->size = icursor->size;
-		ocursor->unique_keys = icursor->unique_keys;
-		ocursor->skip_nulls = icursor->skip_nulls;
-		icursor = icursor->next;
-		if (icursor == NULL)
-			break;
-		ocursor->next = palloc(sizeof(JsonbParseState));
-		ocursor = ocursor->next;
-	}
-	ocursor->next = NULL;
-
-	return result;
-}
-
-static Datum
-jsonb_agg_transfn_worker(FunctionCallInfo fcinfo, bool absent_on_null)
+Datum
+jsonb_agg_transfn(PG_FUNCTION_ARGS)
 {
 	MemoryContext oldcontext,
 				aggcontext;
@@ -1716,7 +1682,7 @@ jsonb_agg_finalfn(PG_FUNCTION_ARGS)
 	 * values, just add the final array end marker.
 	 */
 
-	result.parseState = clone_parse_state(arg->res->parseState);
+	result.parseState = JsonbParseStateClone(arg->res->parseState);
 
 	result.res = pushJsonbValue(&result.parseState,
 								WJB_END_ARRAY, NULL);
@@ -2006,7 +1972,7 @@ jsonb_object_agg_finalfn(PG_FUNCTION_ARGS)
 	 * marker.
 	 */
 
-	result.parseState = clone_parse_state(arg->res->parseState);
+	result.parseState = JsonbParseStateClone(arg->res->parseState);
 
 	result.res = pushJsonbValue(&result.parseState,
 								WJB_END_OBJECT, NULL);

src/backend/utils/adt/jsonb_util.c

@@ -547,6 +547,34 @@ fillJsonbValue(JsonbContainer *container, int index,
 	}
 }
 
+/*
+ * shallow clone of a parse state, suitable for use in aggregate
+ * final functions that will only append to the values rather than
+ * change them.
+ */
+JsonbParseState *
+JsonbParseStateClone(JsonbParseState *state)
+{
+	JsonbParseState	   *result,
+					   *icursor,
+					   *ocursor,
+					  **pocursor = &result;
+
+	for (icursor = state; icursor; icursor = icursor->next)
+	{
+		*pocursor = ocursor = palloc(sizeof(JsonbParseState));
+		ocursor->contVal = icursor->contVal;
+		ocursor->size = icursor->size;
+		ocursor->unique_keys = icursor->unique_keys;
+		ocursor->skip_nulls = icursor->skip_nulls;
+		pocursor = &ocursor->next;
+	}
+
+	*pocursor = NULL;
+
+	return result;
+}
+
 /*
  * Push JsonbValue into JsonbParseState.
  *

src/include/utils/jsonb.h

@@ -405,6 +405,7 @@ extern JsonbValue *getIthJsonbValueFromContainer(JsonbContainer *sheader,
 												 uint32 i);
 extern JsonbValue *pushJsonbValue(JsonbParseState **pstate,
 								  JsonbIteratorToken seq, JsonbValue *jbval);
+extern JsonbParseState *JsonbParseStateClone(JsonbParseState *state);
 extern JsonbIterator *JsonbIteratorInit(JsonbContainer *container);
 extern JsonbIteratorToken JsonbIteratorNext(JsonbIterator **it, JsonbValue *val,
 											bool skipNested);