fix issue that getOrCreateWebSocket is unexpectedly called repeatedly.

app/src/main/java/chat/rocket/android/service/RealmBasedConnectivityManager.java

@@ -64,9 +64,7 @@ import rx.subjects.PublishSubject;
   @Override
   public void ensureConnections() {
     for (String hostname : serverConnectivityList.keySet()) {
-      connectToServer(hostname) //force connect.
-          //.doOnError(RCLog::e)
-          .retryWhen(RxHelper.exponentialBackoff(3, 500, TimeUnit.MILLISECONDS))
+      connectToServerIfNeeded(hostname, true/* force connect */)
           .subscribe(_val -> { }, RCLog::e);
     }
   }
@@ -78,7 +76,7 @@ import rx.subjects.PublishSubject;
     if (!serverConnectivityList.containsKey(hostname)) {
       serverConnectivityList.put(hostname, ServerConnectivity.STATE_DISCONNECTED);
     }
-    connectToServerIfNeeded(hostname)
+    connectToServerIfNeeded(hostname, false)
         .subscribe(_val -> { }, RCLog::e);
   }
 
@@ -93,7 +91,7 @@ import rx.subjects.PublishSubject;
 
   @Override
   public Single<Boolean> connect(String hostname) {
-    return connectToServerIfNeeded(hostname);
+    return connectToServerIfNeeded(hostname, false);
   }
 
   @Override
@@ -136,16 +134,16 @@ import rx.subjects.PublishSubject;
     return Observable.concat(Observable.from(getCurrentConnectivityList()), connectivitySubject);
   }
 
-  private Single<Boolean> connectToServerIfNeeded(String hostname) {
+  private Single<Boolean> connectToServerIfNeeded(String hostname, boolean forceConnect) {
     return Single.defer(() -> {
       final int connectivity = serverConnectivityList.get(hostname);
-      if (connectivity == ServerConnectivity.STATE_CONNECTED) {
+      if (!forceConnect && connectivity == ServerConnectivity.STATE_CONNECTED) {
         return Single.just(true);
       }
 
       if (connectivity == ServerConnectivity.STATE_DISCONNECTING) {
         return waitForDisconnected(hostname)
-            .flatMap(_val -> connectToServerIfNeeded(hostname));
+            .flatMap(_val -> connectToServerIfNeeded(hostname, forceConnect));
       }
 
       if (connectivity == ServerConnectivity.STATE_CONNECTING) {
@@ -167,6 +165,7 @@ import rx.subjects.PublishSubject;
 
       if (connectivity == ServerConnectivity.STATE_CONNECTING) {
         return waitForConnected(hostname)
+            .onErrorReturn(err -> true)
             .flatMap(_val -> disconnectFromServerIfNeeded(hostname));
       }
 
@@ -183,28 +182,40 @@ import rx.subjects.PublishSubject;
 
   private Single<Boolean> waitForConnected(String hostname) {
     return connectivitySubject
-        .filter(serverConnectivity -> (hostname.equals(serverConnectivity.hostname)
-            && serverConnectivity.state == ServerConnectivity.STATE_CONNECTED))
+        .filter(serverConnectivity -> hostname.equals(serverConnectivity.hostname))
+        .map(serverConnectivity -> serverConnectivity.state)
+        .filter(state ->
+            state == ServerConnectivity.STATE_CONNECTED || state == ServerConnectivity.STATE_DISCONNECTED)
         .first()
-        .map(serverConnectivity -> true)
-        .toSingle();
+        .toSingle()
+        .flatMap(state ->
+            state == ServerConnectivity.STATE_CONNECTED
+                ? Single.just(true)
+                : Single.error(new ServerConnectivity.Disconnected()));
   }
 
   private Single<Boolean> waitForDisconnected(String hostname) {
     return connectivitySubject
-        .filter(serverConnectivity -> (hostname.equals(serverConnectivity.hostname)
-            && serverConnectivity.state == ServerConnectivity.STATE_DISCONNECTED))
+        .filter(serverConnectivity -> hostname.equals(serverConnectivity.hostname))
+        .map(serverConnectivity -> serverConnectivity.state)
+        .filter(state -> state == ServerConnectivity.STATE_DISCONNECTED)
         .first()
-        .map(serverConnectivity -> true)
-        .toSingle();
+        .toSingle()
+        .map(state -> true);
   }
 
+  @DebugLog
   private Single<Boolean> connectToServer(String hostname) {
     return Single.defer(() -> {
       if (!serverConnectivityList.containsKey(hostname)) {
         return Single.error(new IllegalArgumentException("hostname not found"));
       }
+
+      if (serverConnectivityList.get(hostname) != ServerConnectivity.STATE_CONNECTED) {
+        // Mark as CONNECTING except for the case [forceConnect && connected] because
+        // webSocketThread#keepAlive doesn't notify ConnectionEstablished/Lost on reconnecting.
         serverConnectivityList.put(hostname, ServerConnectivity.STATE_CONNECTING);
+      }
 
       if (serviceInterface != null) {
         return serviceInterface.ensureConnectionToServer(hostname);

app/src/main/java/chat/rocket/android/service/RocketChatService.java

@@ -93,14 +93,8 @@ public class RocketChatService extends Service implements ConnectivityServiceInt
     return Single.defer(() -> {
       if (webSocketThreads.containsKey(hostname)) {
         RocketChatWebSocketThread thread = webSocketThreads.get(hostname);
-        if (thread != null) {
         return Single.just(thread);
-        } else {
-          return Observable.timer(1, TimeUnit.SECONDS).toSingle()
-              .flatMap(_val -> getOrCreateWebSocketThread(hostname));
-        }
       }
-      webSocketThreads.put(hostname, null);
       return RocketChatWebSocketThread.getStarted(getApplicationContext(), hostname)
           .doOnSuccess(thread -> webSocketThreads.put(hostname, thread));
     });

app/src/main/java/chat/rocket/android/service/ServerConnectivity.java

@@ -16,4 +16,10 @@ public class ServerConnectivity {
     this.hostname = hostname;
     this.state = state;
   }
+
+  public static class Disconnected extends Exception {
+    public Disconnected() {
+      super("Disconnected");
+    }
+  }
 }