MT#56447 allow specific publisher feed ID

Support the "id" parameter for the "join" as "publisher" message.
Preempts choosing a random feed ID.

Add a test case for this.

Change-Id: Iae8c2f50864adf913b288085aa70d5427e0a4456

daemon/janus.c

@@ -507,14 +507,20 @@ static const char *janus_videoroom_join(struct websocket_message *wm, struct jan
 	AUTO_CLEANUP(GQueue ret_streams, janus_clear_ret_streams) = G_QUEUE_INIT; // return list for multiple subs
 
 	if (is_pub) {
-		// random feed ID
-		while (1) {
-			feed_id = janus_random();
+		if (json_reader_read_member(reader, "id")) {
+			feed_id = jr_str_int(reader);
 			if (!feed_id)
-				continue;
+				return "Invalid feed ID requested";
 			if (g_hash_table_lookup(room->feeds, &feed_id))
-				continue;
-			break;
+				return "Feed already exists";
+		}
+		json_reader_end_member(reader);
+
+		// random feed ID?
+		while (!feed_id) {
+			feed_id = janus_random();
+			if (feed_id && g_hash_table_lookup(room->feeds, &feed_id))
+				feed_id = 0;
 		}
 
 		// feed ID points to the handle

t/auto-daemon-tests-websocket.py

@@ -355,13 +355,18 @@ class TestVideoroom(unittest.TestCase):
 
         return handle
 
-    def createPublisher(self, token, session, room, handle, pubs=[], conn_num=0):
+    def createPublisher(self, token, session, room, handle, pubs=[], conn_num=0, feed_id=0):
+        body = {"request": "join", "ptype": "publisher", "room": room}
+
+        if feed_id:
+            body["id"] = feed_id
+
         eventloop.run_until_complete(
             testIOJanus(
                 self,
                 {
                     "janus": "message",
-                    "body": {"request": "join", "ptype": "publisher", "room": room},
+                    "body": body,
                     "handle_id": handle,
                     "session_id": session,
                     "token": token,
@@ -378,6 +383,8 @@ class TestVideoroom(unittest.TestCase):
         self.assertNotEqual(feed, session)
         self.assertNotEqual(feed, room)
         self.assertNotEqual(feed, handle)
+        if feed_id:
+            self.assertEqual(feed_id, feed)
         self.assertEqual(
             self._res,
             {
@@ -1818,7 +1825,7 @@ class TestVideoroom(unittest.TestCase):
         pub_handle = self.createHandle(token, session)
         self.assertNotEqual(pub_handle, control_handle)
 
-        feed = self.createPublisher(token, session, room, pub_handle)
+        feed = self.createPublisher(token, session, room, pub_handle, feed_id=123)
         self.assertNotEqual(feed, control_handle)
 
         eventloop.run_until_complete(