Add temporary stack-allocated expanded Jsons

Author: Nikita Glukhov

src/backend/tsearch/to_tsany.c

@@ -294,7 +294,7 @@ jsonb_string_to_tsvector_byid(PG_FUNCTION_ARGS)
 	TSVector	result;
 
 	result = jsonb_to_tsvector_worker(cfgId, jb, jtiString);
-	PG_FREE_IF_COPY(jb, 1);
+	PG_FREE_IF_COPY_JSONB(jb, 1);
 
 	PG_RETURN_TSVECTOR(result);
 }
@@ -308,7 +308,7 @@ jsonb_string_to_tsvector(PG_FUNCTION_ARGS)
 
 	cfgId = getTSCurrentConfig(true);
 	result = jsonb_to_tsvector_worker(cfgId, jb, jtiString);
-	PG_FREE_IF_COPY(jb, 0);
+	PG_FREE_IF_COPY_JSONB(jb, 0);
 
 	PG_RETURN_TSVECTOR(result);
 }
@@ -323,8 +323,8 @@ jsonb_to_tsvector_byid(PG_FUNCTION_ARGS)
 	uint32		flags = parse_jsonb_index_flags(jbFlags);
 
 	result = jsonb_to_tsvector_worker(cfgId, jb, flags);
-	PG_FREE_IF_COPY(jb, 1);
-	PG_FREE_IF_COPY(jbFlags, 2);
+	PG_FREE_IF_COPY_JSONB(jb, 1);
+	PG_FREE_IF_COPY_JSONB(jbFlags, 2);
 
 	PG_RETURN_TSVECTOR(result);
 }
@@ -340,8 +340,8 @@ jsonb_to_tsvector(PG_FUNCTION_ARGS)
 
 	cfgId = getTSCurrentConfig(true);
 	result = jsonb_to_tsvector_worker(cfgId, jb, flags);
-	PG_FREE_IF_COPY(jb, 0);
-	PG_FREE_IF_COPY(jbFlags, 1);
+	PG_FREE_IF_COPY_JSONB(jb, 0);
+	PG_FREE_IF_COPY_JSONB(jbFlags, 1);
 
 	PG_RETURN_TSVECTOR(result);
 }
@@ -387,7 +387,11 @@ json_string_to_tsvector_byid(PG_FUNCTION_ARGS)
 	TSVector	result;
 
 	result = json_to_tsvector_worker(cfgId, json, jtiString);
+#ifndef JSON_GENERIC
 	PG_FREE_IF_COPY(json, 1);
+#else
+	PG_FREE_IF_COPY_JSONB(json, 1);
+#endif
 
 	PG_RETURN_TSVECTOR(result);
 }
@@ -405,7 +409,11 @@ json_string_to_tsvector(PG_FUNCTION_ARGS)
 
 	cfgId = getTSCurrentConfig(true);
 	result = json_to_tsvector_worker(cfgId, json, jtiString);
+#ifndef JSON_GENERIC
 	PG_FREE_IF_COPY(json, 0);
+#else
+	PG_FREE_IF_COPY_JSONB(json, 0);
+#endif
 
 	PG_RETURN_TSVECTOR(result);
 }
@@ -424,8 +432,12 @@ json_to_tsvector_byid(PG_FUNCTION_ARGS)
 	uint32		flags = parse_jsonb_index_flags(jbFlags);
 
 	result = json_to_tsvector_worker(cfgId, json, flags);
+#ifndef JSON_GENERIC
 	PG_FREE_IF_COPY(json, 1);
-	PG_FREE_IF_COPY(jbFlags, 2);
+#else
+	PG_FREE_IF_COPY_JSONB(json, 1);
+#endif
+	PG_FREE_IF_COPY_JSONB(jbFlags, 2);
 
 	PG_RETURN_TSVECTOR(result);
 }
@@ -445,8 +457,12 @@ json_to_tsvector(PG_FUNCTION_ARGS)
 
 	cfgId = getTSCurrentConfig(true);
 	result = json_to_tsvector_worker(cfgId, json, flags);
+#ifndef JSON_GENERIC
 	PG_FREE_IF_COPY(json, 0);
-	PG_FREE_IF_COPY(jbFlags, 1);
+#else
+	PG_FREE_IF_COPY_JSONB(json, 0);
+#endif
+	PG_FREE_IF_COPY_JSONB(jbFlags, 1);
 
 	PG_RETURN_TSVECTOR(result);
 }

src/backend/tsearch/wparser.c

@@ -407,7 +407,7 @@ ts_headline_jsonb_byid_opt(PG_FUNCTION_ARGS)
 	/* flatten result to jsonb before jb freeing */
 	res = JsonFlattenToJsonbDatum(out);
 
-	PG_FREE_IF_COPY(jb, 1);
+	PG_FREE_IF_COPY_JSONB(jb, 1);
 	PG_FREE_IF_COPY(query, 2);
 	if (opt)
 		PG_FREE_IF_COPY(opt, 3);
@@ -488,6 +488,7 @@ ts_headline_json_byid_opt(PG_FUNCTION_ARGS)
 
 #ifndef JSON_GENERIC
 	out = transform_json_string_values(json, state, action);
+	PG_FREE_IF_COPY(json, 1);
 #else
 	{
 		Jsonb	   *jsonb = transform_jsonb_string_values(json, state, action);
@@ -496,10 +497,11 @@ ts_headline_json_byid_opt(PG_FUNCTION_ARGS)
 		out = cstring_to_text(str);
 
 		pfree(str);
+
+		PG_FREE_IF_COPY_JSONB(json, 1);
 	}
 #endif
 
-	PG_FREE_IF_COPY(json, 1);
 	PG_FREE_IF_COPY(query, 2);
 	if (opt)
 		PG_FREE_IF_COPY(opt, 3);

src/backend/utils/adt/expandeddatum.c

@@ -14,6 +14,7 @@
  */
 #include "postgres.h"
 
+#include "utils/datum.h"
 #include "utils/expandeddatum.h"
 #include "utils/memutils.h"
 
@@ -122,6 +123,9 @@ TransferExpandedObject(Datum d, MemoryContext new_parent)
 	/* Assert caller gave a R/W pointer */
 	Assert(VARATT_IS_EXTERNAL_EXPANDED_RW(DatumGetPointer(d)));
 
+	if (!eohptr->eoh_context)
+		return datumCopy(d, false, -1);
+
 	/* Transfer ownership */
 	MemoryContextSetParent(eohptr->eoh_context, new_parent);
 
@@ -141,5 +145,8 @@ DeleteExpandedObject(Datum d)
 	Assert(VARATT_IS_EXTERNAL_EXPANDED_RW(DatumGetPointer(d)));
 
 	/* Kill it */
-	MemoryContextDelete(eohptr->eoh_context);
+	if (eohptr->eoh_context)
+		MemoryContextDelete(eohptr->eoh_context);
+	else
+		pfree(eohptr);
 }

src/backend/utils/adt/json_generic.c

@@ -16,7 +16,9 @@
 
 static JsonContainerOps jsonvContainerOps;
 
-static Json *JsonExpand(Datum value, JsonContainerOps *ops);
+static Json *JsonExpand(Json *tmp, Datum value, bool freeValue,
+						JsonContainerOps *ops);
+
 
 #if 0
 static JsonValue *
@@ -608,8 +610,7 @@ jsonWriteExtended(JsonContainer *jc, void *ptr, Size allocated_size)
 }
 
 static Json *
-JsonInitExtended(const struct varlena *toasted,
-				 const struct varlena *detoasted)
+JsonInitExtended(Json *tmp, struct varlena *extvalue, bool freeValue)
 {
 	JsonContainerOps	   *ops;
 	CompressionMethodRoutine *cmr;
@@ -619,10 +620,12 @@ JsonInitExtended(const struct varlena *toasted,
 	int						len;
 	Datum					value;
 
-	Assert(VARATT_IS_EXTERNAL_EXTENDED(detoasted));
+	Assert(VARATT_IS_EXTERNAL_EXTENDED(extvalue));
+
+	pextjs = (varatt_extended_json *) VARDATA_EXTERNAL(extvalue);
+	memcpy(&extjs, pextjs, offsetof(varatt_extended_json, data));
 
-	pextjs = (varatt_extended_json *) VARDATA_EXTERNAL(detoasted);
-	memcpy(&extjs, pextjs, offsetof(varatt_extended_json, params));
+	totalSize = extjs.vaext.size - offsetof(varatt_extended_json, data);
 
 	ops = JsonContainerGetOpsByType(extjs.type);
 
@@ -642,8 +645,11 @@ JsonInitExtended(const struct varlena *toasted,
 	SET_VARSIZE(val, VARHDRSZ + len);
 	memcpy(VARDATA(val), &pextjs->params, len);
 
+	if (freeValue)
+		pfree(extvalue);
+
 	if (ops)
-		return JsonExpand(PointerGetDatum(val), ops);
+		return JsonExpand(tmp, value, true, ops);
 
 	value = cmr->decompress(PointerGetDatum(val), NULL);
 
@@ -656,19 +662,19 @@ JsonInitExtended(const struct varlena *toasted,
 static void
 JsonInit(Json *json)
 {
-	const void *data = DatumGetPointer(json->obj.compressed);
+	const void *data = DatumGetPointer(json->obj.value);
+	const void *detoasted_data;
 
 	Assert(json->root.data || data);
 
 	if (json->root.data || !data)
 		return;
 
-	data = PG_DETOAST_DATUM(json->obj.compressed);
-
-	/* Assert(!VARATT_IS_EXTERNAL_EXTENDED(data)); */
-	json->obj.compressed = PointerGetDatum(data);
+	detoasted_data = PG_DETOAST_DATUM(json->obj.value);
+	json->obj.value = PointerGetDatum(detoasted_data);
+	json->obj.freeValue |= data != detoasted_data;
 
-	(*json->root.ops->init)(&json->root, json->obj.compressed);
+	json->root.ops->init(&json->root, json->obj.value);
 }
 
 static Size
@@ -824,27 +830,41 @@ jsonExpandedObjectMethods =
 };
 
 static Json *
-JsonExpand(Datum value, JsonContainerOps *ops)
+JsonExpand(Json *tmp, Datum value, bool freeValue, JsonContainerOps *ops)
 {
 	MemoryContext	objcxt;
 	Json		   *json;
 
-	/*
-	 * Allocate private context for expanded object.  We start by assuming
-	 * that the json won't be very large; but if it does grow a lot, don't
-	 * constrain aset.c's large-context behavior.
-	 */
-	objcxt = AllocSetContextCreate(CurrentMemoryContext,
-								   "expanded json",
-								   ALLOCSET_SMALL_MINSIZE,
-								   ALLOCSET_SMALL_INITSIZE,
-								   ALLOCSET_DEFAULT_MAXSIZE);
-
-	json = (Json *) MemoryContextAlloc(objcxt, sizeof(Json));
+	if (tmp)
+	{
+		json = tmp;
+		json->obj.eoh.vl_len_ = 0;
+	}
+	else
+	{
+#ifndef JSON_EXPANDED_OBJECT_MCXT
+		json = (Json *) palloc(sizeof(Json));
+		objcxt = NULL;
+#else
+		/*
+		 * Allocate private context for expanded object.  We start by assuming
+		 * that the json won't be very large; but if it does grow a lot, don't
+		 * constrain aset.c's large-context behavior.
+		 */
+		objcxt = AllocSetContextCreate(CurrentMemoryContext,
+									   "expanded json",
+									   ALLOCSET_SMALL_MINSIZE,
+									   ALLOCSET_SMALL_INITSIZE,
+									   ALLOCSET_DEFAULT_MAXSIZE);
+
+		json = (Json *) MemoryContextAlloc(objcxt, sizeof(Json));
+#endif
 
-	EOH_init_header(&json->obj.eoh, &jsonExpandedObjectMethods, objcxt);
+		EOH_init_header(&json->obj.eoh, &jsonExpandedObjectMethods, objcxt);
+	}
 
-	json->obj.compressed = value;
+	json->obj.value = value;
+	json->obj.freeValue = freeValue;
 	json->root.data = NULL;
 	json->root.len = 0;
 	json->root.ops = ops;
@@ -855,8 +875,8 @@ JsonExpand(Datum value, JsonContainerOps *ops)
 	return json;
 }
 
-Json *
-DatumGetJson(Datum value, JsonContainerOps *ops)
+static Json *
+JsonExpandDatum(Datum value, JsonContainerOps *ops, Json *tmp)
 {
 	struct varlena *toasted = (struct varlena *) DatumGetPointer(value);
 	Json	   *json;
@@ -870,32 +890,66 @@ DatumGetJson(Datum value, JsonContainerOps *ops)
 /*
 		if (VARATT_IS_EXTERNAL_EXTENDED(detoasted))
 #ifdef JSON_FLATTEN_INTO_JSONEXT
-			return JsonInitExtended(toasted, detoasted);
+			return JsonInitExtended(tmp, detoasted, toasted != detoasted);
 #else
 			elog(ERROR, "unexpected extended json");
 #endif
 */
 
-		json = JsonExpand(PointerGetDatum(detoasted), ops);
+		json = JsonExpand(tmp, PointerGetDatum(detoasted), toasted != detoasted,
+						  ops);
 	}
 
+	return json;
+}
+
+Json *
+DatumGetJson(Datum value, JsonContainerOps *ops, Json *tmp)
+{
+	Json *json = JsonExpandDatum(value, ops, tmp);
 	JsonInit(json);
 
 	return json;
 }
 
+void
+JsonFree(Json *json)
+{
+	if (json->obj.freeValue)
+		pfree(DatumGetPointer(json->obj.value));
+
+	if (!JsonIsTemporary(json))
+		pfree(json);
+}
+
+Json *
+JsonCopyTemporary(Json *tmp)
+{
+	Json *json = (Json *) palloc(sizeof(Json));
+
+	memcpy(json, tmp, sizeof(Json));
+	tmp->obj.freeValue = false;
+
+	EOH_init_header(&json->obj.eoh, &jsonExpandedObjectMethods, NULL);
+
+	return json;
+}
+
 Json *
 JsonValueToJson(JsonValue *val)
 {
 	if (val->type == jbvBinary)
 	{
-		Json *json = JsonExpand(PointerGetDatum(NULL), NULL);
-		json->root = *val->val.binary.data;
+		JsonContainer  *jc = val->val.binary.data;
+		Json		   *json = JsonExpand(NULL, PointerGetDatum(NULL), false,
+										  jc->ops);
+		json->root = *jc;
 		return json;
 	}
 	else
 	{
-		Json *json = JsonExpand(PointerGetDatum(NULL), &jsonvContainerOps);
+		Json *json = JsonExpand(NULL, PointerGetDatum(NULL), false,
+								&jsonvContainerOps);
 		jsonvInitContainer(&json->root, val);
 		return json;
 	}