fix(whisper): Fixes leaking whisper connections. (#511)

* fix(whisper): Fixes leaking whisper connections.

Moves setting transcriber room name earlier, so we can use it in creating the transcriber sessions.

When a participant never talked, is missing in one of the participants lists and those got desync and we never remove the websocket from the pool, which results in reusing it for the same room (the socket has timeouted and disconnected) and there is a NPE that prevents transcriptions in the meeting.
2023-11-30 13:09:17.645 SEVERE: [188854] org.jivesoftware.smack.AbstractXMPPConnection.lambda$invokeStanzaCollectorsAndNotifyRecvListeners$8: Exception in packet listener
java.lang.NullPointerException
	at org.jitsi.jigasi.transcription.WhisperWebsocket.addParticipantIfNotExists(WhisperWebsocket.java:362)
	at org.jitsi.jigasi.transcription.WhisperWebsocket.addListener(WhisperWebsocket.java:373)
	at org.jitsi.jigasi.transcription.WhisperTranscriptionService$WhisperWebsocketStreamingSession.addTranscriptionListener(WhisperTranscriptionService.java:170)
	at org.jitsi.jigasi.transcription.Participant.joined(Participant.java:524)

* squash: Fixes some warnings.

src/main/java/org/jitsi/jigasi/TranscriptionGatewaySession.java

@@ -128,6 +128,8 @@ public TranscriptionGatewaySession(AbstractGateway gateway,
             this.transcriber.addTranscriptionEventListener(
                 (TranscriptionEventListener)this.service);
         }
+
+        transcriber.setRoomName(this.getCallContext().getRoomJid().toString());
     }
 
     @Override
@@ -137,7 +139,6 @@ void onConferenceCallInvited(Call incomingCall)
         // the room name, url and start listening
         transcriber.addTranscriptionListener(this);
         transcriber.addTranslationListener(this);
-        transcriber.setRoomName(this.getCallContext().getRoomJid().toString());
         transcriber.setRoomUrl(getMeetingUrl());
 
         // We create a MediaWareCallConference whose MediaDevice
@@ -318,7 +319,7 @@ void notifyChatRoomMemberUpdated(ChatRoomMember chatMember, Presence presence)
                 }
                 catch (InterruptedException e)
                 {
-                    e.printStackTrace();
+                    logger.error(e);
                 }
 
                 if (!transcriber.isAnyParticipantRequestingTranscription())
@@ -563,7 +564,7 @@ private String getConferenceMemberResourceID(ConferenceMember member)
         }
         catch (XmppStringprepException e)
         {
-            e.printStackTrace();
+            logger.error(e);
         }
 
         return null;

src/main/java/org/jitsi/jigasi/transcription/WhisperConnectionPool.java

@@ -47,35 +47,19 @@ public class WhisperConnectionPool
     /**
      * A hashmap holding the state for each connection
      */
-    private final Map<String, ConnectionState> pool = new ConcurrentHashMap<>();
+    private final Map<String, WhisperWebsocket> pool = new ConcurrentHashMap<>();
 
     /**
      * The thread pool to serve all connect disconnect operations.
      */
-    private static ExecutorService threadPool = Util.createNewThreadPool("jigasi-whisper-ws");
-
-
-    private static class ConnectionState
-    {
-        public WhisperWebsocket wsConn;
-        public HashSet<String> participants = new HashSet<>();
-
-        public ConnectionState(WhisperWebsocket ws)
-        {
-            wsConn = ws;
-        }
-
-    }
+    private static final ExecutorService threadPool = Util.createNewThreadPool("jigasi-whisper-ws");
 
     /**
      * Gets a connection if it exists, creates one if it doesn't.
      * @param roomId The room jid.
-     * @param participantId The participant id.
      * @return The websocket.
-     * @throws Exception When fail to initialize the socket.
      */
-    public WhisperWebsocket getConnection(String roomId, String participantId)
-        throws Exception
+    public WhisperWebsocket getConnection(String roomId)
     {
         if (!pool.containsKey(roomId))
         {
@@ -85,11 +69,10 @@ public WhisperWebsocket getConnection(String roomId, String participantId)
             // connect socket in new thread to not block Smack threads
             threadPool.execute(socket::connect);
 
-            pool.put(roomId, new ConnectionState(socket));
+            pool.put(roomId, socket);
         }
 
-        pool.get(roomId).participants.add(participantId);
-        return pool.get(roomId).wsConn;
+        return pool.get(roomId);
     }
 
     /**
@@ -99,38 +82,23 @@ public WhisperWebsocket getConnection(String roomId, String participantId)
      */
     public void end(String roomId, String participantId)
     {
-        // execute thi in new thread to not block Smack
-        threadPool.execute(() -> {
-            this.endInternal(roomId, participantId);
-        });
+        // execute this in new thread to not block Smack
+        threadPool.execute(() -> this.endInternal(roomId, participantId));
     }
 
     private void endInternal(String roomId, String participantId)
     {
-        ConnectionState state = pool.getOrDefault(roomId, null);
-        if (state == null)
-        {
-            return;
-        }
-
-        if (!state.participants.contains(participantId))
-        {
-            return;
-        }
-
-        state.participants.remove(participantId);
-
-        if (!state.participants.isEmpty())
+        WhisperWebsocket wsConn = pool.getOrDefault(roomId, null);
+        if (wsConn == null)
         {
             return;
         }
 
-        boolean isEverybodyDisconnected = false;
         try
         {
-            isEverybodyDisconnected = state.wsConn.disconnectParticipant(participantId);
-            if (isEverybodyDisconnected)
+            if (wsConn.disconnectParticipant(participantId))
             {
+                // remove from the pull if everyone is disconnected
                 pool.remove(roomId);
             }
         }

src/main/java/org/jitsi/jigasi/transcription/WhisperTranscriptionService.java

@@ -136,14 +136,13 @@ public static class WhisperWebsocketStreamingSession
 
 
         WhisperWebsocketStreamingSession(Participant participant)
-                throws Exception
         {
             this.participant = participant;
             String[] debugName = this.participant.getDebugName().split("/");
             participantId = debugName[1];
-            roomId = debugName[0];
+            roomId = participant.getTranscriber().getRoomName();
             connectionPool = WhisperConnectionPool.getInstance();
-            wsClient = connectionPool.getConnection(roomId, participantId);
+            wsClient = connectionPool.getConnection(roomId);
             wsClient.setTranscriptionTag(transcriptionTag);
         }