json: add and use spa_json_str_object_find()

Parse a string as a json object and copy the value with key as a string.

pipewire-alsa/alsa-plugins/ctl_pipewire.c

@@ -1019,23 +1019,6 @@ static const struct global_info node_info = {
 };
 
 /** metadata */
-static int json_object_find(const char *obj, const char *key, char *value, size_t len)
-{
-	struct spa_json it[1];
-	const char *v;
-	int l, kl = strlen(key) + 3;
-	char k[kl];
-
-	if (spa_json_begin_object(&it[0], obj, strlen(obj)) <= 0)
-		return -EINVAL;
-
-	while ((l = spa_json_object_next(&it[0], k, kl, &v)) > 0) {
-		if (spa_streq(k, key))
-			return spa_json_parse_stringn(v, l, value, len);
-	}
-	return -ENOENT;
-}
-
 static int metadata_property(void *data,
                         uint32_t subject,
                         const char *key,
@@ -1048,14 +1031,14 @@ static int metadata_property(void *data,
 	if (subject == PW_ID_CORE) {
 		if (key == NULL || spa_streq(key, "default.audio.sink")) {
 			if (value == NULL ||
-			    json_object_find(value, "name",
+			    spa_json_str_object_find(value, strlen(value), "name",
 					ctl->default_sink, sizeof(ctl->default_sink)) < 0)
 				ctl->default_sink[0] = '\0';
 			pw_log_debug("found default sink: %s", ctl->default_sink);
 		}
 		if (key == NULL || spa_streq(key, "default.audio.source")) {
 			if (value == NULL ||
-			    json_object_find(value, "name",
+			    spa_json_str_object_find(value, strlen(value), "name",
 					ctl->default_source, sizeof(ctl->default_source)) < 0)
 				ctl->default_source[0] = '\0';
 			pw_log_debug("found default source: %s", ctl->default_source);

pipewire-jack/src/pipewire-jack.c

@@ -3456,23 +3456,6 @@ static jack_uuid_t client_make_uuid(uint32_t id, bool monitor)
 	return uuid;
 }
 
-static int json_object_find(const char *obj, const char *key, char *value, size_t len)
-{
-	struct spa_json it[1];
-	const char *v;
-	int l, kl = strlen(key) + 3;
-	char k[kl];
-
-	if (spa_json_begin_object(&it[0], obj, strlen(obj)) <= 0)
-		return -EINVAL;
-
-	while ((l = spa_json_object_next(&it[0], k, kl, &v)) > 0) {
-		if (spa_streq(k, key))
-			return spa_json_parse_stringn(v, l, value, len);
-	}
-	return -ENOENT;
-}
-
 static int metadata_property(void *data, uint32_t id,
 		const char *key, const char *type, const char *value)
 {
@@ -3485,7 +3468,7 @@ static int metadata_property(void *data, uint32_t id,
 	if (id == PW_ID_CORE) {
 		if (key == NULL || spa_streq(key, "default.audio.sink")) {
 			if (value != NULL) {
-				if (json_object_find(value, "name",
+				if (spa_json_str_object_find(value, strlen(value), "name",
 						c->metadata->default_audio_sink,
 						sizeof(c->metadata->default_audio_sink)) < 0)
 					value = NULL;
@@ -3495,7 +3478,7 @@ static int metadata_property(void *data, uint32_t id,
 		}
 		if (key == NULL || spa_streq(key, "default.audio.source")) {
 			if (value != NULL) {
-				if (json_object_find(value, "name",
+				if (spa_json_str_object_find(value, strlen(value), "name",
 						c->metadata->default_audio_source,
 						sizeof(c->metadata->default_audio_source)) < 0)
 					value = NULL;

spa/include/spa/utils/json.h

@@ -145,6 +145,32 @@ static inline int spa_json_object_next(struct spa_json *iter, char *key, int max
 	}
 }
 
+static inline int spa_json_object_find(struct spa_json *iter, const char *key, const char **value)
+{
+	struct spa_json obj = SPA_JSON_SAVE(iter);
+	int res, len = strlen(key) + 3;
+	char k[len];
+
+	while ((res = spa_json_object_next(&obj, k, len, value)) > 0)
+		if (spa_streq(k, key))
+			return res;
+	return -ENOENT;
+}
+
+static inline int spa_json_str_object_find(const char *obj, size_t obj_len,
+		const char *key, char *value, size_t maxlen)
+{
+	struct spa_json iter;
+	int l;
+	const char *v;
+
+	if (spa_json_begin_object(&iter, obj, obj_len) <= 0)
+		return -EINVAL;
+	if ((l = spa_json_object_find(&iter, key, &v)) <= 0)
+		return l;
+	return spa_json_parse_stringn(v, l, value, maxlen);
+}
+
 /* array */
 static inline int spa_json_enter_array(struct spa_json *iter, struct spa_json *sub)
 {

src/gst/gstpipewiredeviceprovider.c

@@ -510,29 +510,6 @@ static const struct pw_proxy_events proxy_port_events = {
   .destroy = destroy_port,
 };
 
-static int json_object_find(const char *obj, const char *key, char *value,
-                            size_t len) {
-  struct spa_json it[2];
-  const char *v;
-  char k[128];
-
-  spa_json_init(&it[0], obj, strlen(obj));
-  if (spa_json_enter_object(&it[0], &it[1]) <= 0)
-    return -EINVAL;
-
-  while (spa_json_get_string(&it[1], k, sizeof(k)) > 0) {
-    if (spa_streq(k, key)) {
-      if (spa_json_get_string(&it[1], value, len) <= 0)
-        continue;
-      return 0;
-    } else {
-      if (spa_json_next(&it[1], &v) <= 0)
-        break;
-    }
-  }
-  return -ENOENT;
-}
-
 static int metadata_property(void *data, uint32_t id, const char *key,
                              const char *type, const char *value) {
   GstPipeWireDeviceProvider *self = data;
@@ -546,7 +523,7 @@ static int metadata_property(void *data, uint32_t id, const char *key,
       return 0;
 
     g_free(self->default_audio_source_name);
-    if (json_object_find(value, "name", name, sizeof(name)) >= 0)
+    if (spa_json_str_object_find(value, strlen(value), "name", name, sizeof(name)) >= 0)
       self->default_audio_source_name = g_strdup(name);
     return 0;
   }
@@ -555,7 +532,7 @@ static int metadata_property(void *data, uint32_t id, const char *key,
       return 0;
 
     g_free(self->default_audio_sink_name);
-    if (json_object_find(value, "name", name, sizeof(name)) >= 0)
+    if (spa_json_str_object_find(value, strlen(value), "name", name, sizeof(name)) >= 0)
       self->default_audio_sink_name = g_strdup(name);
     return 0;
   }
@@ -564,7 +541,7 @@ static int metadata_property(void *data, uint32_t id, const char *key,
       return 0;
 
     g_free(self->default_video_source_name);
-    if (json_object_find(value, "name", name, sizeof(name)) >= 0)
+    if (spa_json_str_object_find(value, strlen(value), "name", name, sizeof(name)) >= 0)
       self->default_video_source_name = g_strdup(name);
     return 0;
   }

src/modules/module-protocol-pulse/pulse-server.c

@@ -928,26 +928,6 @@ static void manager_object_data_timeout(void *data, struct pw_manager_object *o,
 		temporary_move_target_timeout(client, o);
 }
 
-static int json_object_find(const char *obj, const char *key, char *value, size_t len)
-{
-	struct spa_json it[1];
-	const char *v;
-	char k[128];
-	int l;
-
-	if (spa_json_begin_object(&it[0], obj, strlen(obj)) <= 0)
-		return -EINVAL;
-
-	while ((l = spa_json_object_next(&it[0], k, sizeof(k), &v)) > 0) {
-		if (spa_streq(k, key)) {
-			if (spa_json_parse_stringn(v, l, value, len) <= 0)
-				continue;
-			return 0;
-		}
-	}
-	return -ENOENT;
-}
-
 static void manager_metadata(void *data, struct pw_manager_object *o,
 		uint32_t subject, const char *key, const char *type, const char *value)
 {
@@ -962,7 +942,7 @@ static void manager_metadata(void *data, struct pw_manager_object *o,
 
 		if (key == NULL || spa_streq(key, "default.audio.sink")) {
 			if (value != NULL) {
-				if (json_object_find(value,
+				if (spa_json_str_object_find(value, strlen(value),
 						"name", name, sizeof(name)) < 0)
 					value = NULL;
 				else
@@ -977,7 +957,7 @@ static void manager_metadata(void *data, struct pw_manager_object *o,
 		}
 		if (key == NULL || spa_streq(key, "default.audio.source")) {
 			if (value != NULL) {
-				if (json_object_find(value,
+				if (spa_json_str_object_find(value, strlen(value),
 						"name", name, sizeof(name)) < 0)
 					value = NULL;
 				else

test/test-spa-json.c

@@ -1065,6 +1065,38 @@ PWTEST(json_data)
 	return PWTEST_PASS;
 }
 
+PWTEST(json_object_find)
+{
+	const char *json = " { "
+		"\"foo\": \"bar\","
+		"\"int-key\": 42,"
+		"\"list-key\": [],"
+		"\"obj-key\": {},"
+		"\"bool-key\": true,"
+		"\"float-key\": 66.6"
+		" } ";
+	char value[128];
+
+	pwtest_int_eq(spa_json_str_object_find(json, strlen(json), "unknown-key", value, 128), -2);
+	pwtest_int_eq(spa_json_str_object_find("{", 1, "key", value, 128), -2);
+	pwtest_int_eq(spa_json_str_object_find("this is no json", 15, "key", value, 128), -22);
+	pwtest_int_eq(spa_json_str_object_find(json, strlen(json), "foo", value, 128), 1);
+	pwtest_str_eq(value, "bar");
+	pwtest_int_eq(spa_json_str_object_find(json, strlen(json), "int-key", value, 128), 1);
+	pwtest_str_eq(value, "42");
+	pwtest_int_eq(spa_json_str_object_find(json, strlen(json), "list-key", value, 128), 1);
+	pwtest_str_eq(value, "[");
+	pwtest_int_eq(spa_json_str_object_find(json, strlen(json), "obj-key", value, 128), 1);
+	pwtest_str_eq(value, "{");
+	pwtest_int_eq(spa_json_str_object_find(json, strlen(json), "bool-key", value, 128), 1);
+	pwtest_str_eq(value, "true");
+	pwtest_int_eq(spa_json_str_object_find(json, strlen(json), "float-key", value, 128), 1);
+	pwtest_str_eq(value, "66.6");
+
+	return PWTEST_PASS;
+}
+
+
 PWTEST_SUITE(spa_json)
 {
 	pwtest_add(json_abi, PWTEST_NOARG);
@@ -1077,6 +1109,7 @@ PWTEST_SUITE(spa_json)
 	pwtest_add(json_float_check, PWTEST_NOARG);
 	pwtest_add(json_int, PWTEST_NOARG);
 	pwtest_add(json_data, PWTEST_NOARG);
+	pwtest_add(json_object_find, PWTEST_NOARG);
 
 	return PWTEST_PASS;
 }