Add json[b]_extract_keys()

Nikita Glukhov · Nikita Glukhov · commit a0af4adbcd27 · 2017-05-02T21:38:30.000+03:00
diff --git a/src/backend/utils/adt/json.c b/src/backend/utils/adt/json.c
@@ -55,6 +55,7 @@
 #define jsonb_object_field			json_object_field
 #define jsonb_object_field_text		json_object_field_text
 #define jsonb_object_keys			json_object_keys
+#define jsonb_extract_keys			json_extract_keys
 #define jsonb_populate_record		json_populate_record
 #define jsonb_populate_recordset	json_populate_recordset
 #define jsonb_pretty				json_pretty
diff --git a/src/backend/utils/adt/jsonfuncs.c b/src/backend/utils/adt/jsonfuncs.c
@@ -519,8 +519,8 @@ static Datum jsonb_strip_nulls_internal(Jsonb *jb);
  * limited in size to NAMEDATALEN and the number of keys is unlikely to
  * be so huge that it has major memory implications.
  */
-Datum
-jsonb_object_keys(PG_FUNCTION_ARGS)
+static Datum
+jsonb_extract_keys_internal(FunctionCallInfo fcinfo, bool outermost)
 {
 	FuncCallContext *funcctx;
 	OkeysState *state;
@@ -535,18 +535,25 @@ jsonb_object_keys(PG_FUNCTION_ARGS)
 		JsonbValue	v;
 		JsonbIteratorToken r;
 
-		if (JB_ROOT_IS_SCALAR(jb))
-			ereport(ERROR,
-					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
-					 errmsg("cannot call %s on a scalar",
-							JSONB"_object_keys")));
-		else if (JB_ROOT_IS_ARRAY(jb))
-			ereport(ERROR,
-					(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
-					 errmsg("cannot call %s on an array",
-							JSONB"_object_keys")));
+		if (outermost)
+		{
+			if (JB_ROOT_IS_SCALAR(jb))
+				ereport(ERROR,
+						(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+						 errmsg("cannot call %s on a scalar",
+								JSONB"_object_keys")));
+			else if (JB_ROOT_IS_ARRAY(jb))
+				ereport(ERROR,
+						(errcode(ERRCODE_INVALID_PARAMETER_VALUE),
+						 errmsg("cannot call %s on an array",
+								JSONB"_object_keys")));
+		}
 
 		funcctx = SRF_FIRSTCALL_INIT();
+
+		if (!outermost && JB_ROOT_IS_SCALAR(jb))
+			SRF_RETURN_DONE(funcctx);
+
 		oldcontext = MemoryContextSwitchTo(funcctx->multi_call_memory_ctx);
 
 		state = palloc(sizeof(OkeysState));
@@ -562,7 +569,7 @@ jsonb_object_keys(PG_FUNCTION_ARGS)
 
 		while ((r = JsonbIteratorNext(&it, &v, skipNested)) != WJB_DONE)
 		{
-			skipNested = true;
+			skipNested = outermost;
 
 			if (r == WJB_KEY)
 			{
@@ -604,6 +611,17 @@ jsonb_object_keys(PG_FUNCTION_ARGS)
 	SRF_RETURN_DONE(funcctx);
 }
 
+Datum
+jsonb_object_keys(PG_FUNCTION_ARGS)
+{
+	return jsonb_extract_keys_internal(fcinfo, true);
+}
+
+Datum
+jsonb_extract_keys(PG_FUNCTION_ARGS)
+{
+	return jsonb_extract_keys_internal(fcinfo, false);
+}
 
 #ifndef JSON_GENERIC
 Datum
diff --git a/src/include/catalog/pg_proc.h b/src/include/catalog/pg_proc.h
@@ -4507,6 +4507,8 @@ DATA(insert OID = 3956 (  json_array_length			PGNSP PGUID 12 1 0 0 0 f f f f t f
 DESCR("length of json array");
 DATA(insert OID = 3957 (  json_object_keys			PGNSP PGUID 12 1 100 0 0 f f f f t t i s 1 0 25 "114" _null_ _null_ _null_ _null_ _null_ json_object_keys _null_ _null_ _null_ ));
 DESCR("get json object keys");
+DATA(insert OID = 4159 (  json_extract_keys			PGNSP PGUID 12 1 100 0 0 f f f f t t i s 1 0 25 "114" _null_ _null_ _null_ _null_ _null_ json_extract_keys _null_ _null_ _null_ ));
+DESCR("extract all keys from a json");
 DATA(insert OID = 3958 (  json_each				   PGNSP PGUID 12 1 100 0 0 f f f f t t i s 1 0 2249 "114" "{114,25,114}" "{i,o,o}" "{from_json,key,value}" _null_ _null_ json_each _null_ _null_ _null_ ));
 DESCR("key value pairs of a json object");
 DATA(insert OID = 3959 (  json_each_text		   PGNSP PGUID 12 1 100 0 0 f f f f t t i s 1 0 2249 "114" "{114,25,25}" "{i,o,o}" "{from_json,key,value}" _null_ _null_ json_each_text _null_ _null_ _null_ ));
@@ -4957,6 +4959,8 @@ DATA(insert OID = 3207 (  jsonb_array_length			PGNSP PGUID 12 1 0 0 0 f f f f t
 DESCR("length of jsonb array");
 DATA(insert OID = 3931 (  jsonb_object_keys			PGNSP PGUID 12 1 100 0 0 f f f f t t i s 1 0 25 "3802" _null_ _null_ _null_ _null_ _null_ jsonb_object_keys _null_ _null_ _null_ ));
 DESCR("get jsonb object keys");
+DATA(insert OID = 4158 (  jsonb_extract_keys		PGNSP PGUID 12 1 100 0 0 f f f f t t i s 1 0 25 "3802" _null_ _null_ _null_ _null_ _null_ jsonb_extract_keys _null_ _null_ _null_ ));
+DESCR("extract all keys from a jsonb");
 DATA(insert OID = 3208 (  jsonb_each				   PGNSP PGUID 12 1 100 0 0 f f f f t t i s 1 0 2249 "3802" "{3802,25,3802}" "{i,o,o}" "{from_json,key,value}" _null_ _null_ jsonb_each _null_ _null_ _null_ ));
 DESCR("key value pairs of a jsonb object");
 DATA(insert OID = 3932 (  jsonb_each_text		   PGNSP PGUID 12 1 100 0 0 f f f f t t i s 1 0 2249 "3802" "{3802,25,25}" "{i,o,o}" "{from_json,key,value}" _null_ _null_ jsonb_each_text _null_ _null_ _null_ ));
