Send system info and close message no more than once. (#316)

Sometimes system info and close message may be sent to remote side more
than once. It caused PeerConnection to be closed if a close message is
sent in the middle of a call.

Author: jianjunz

src/sdk/p2p/p2pclient.js

@@ -95,13 +95,13 @@ const P2PClient = function(configuration, signalingChannel) {
     const data = JSON.parse(message);
     if (data.type === 'chat-closed') {
       if (channels.has(origin)) {
-        getOrCreateChannel(origin).onMessage(data);
+        getOrCreateChannel(origin, false).onMessage(data);
         channels.delete(origin);
       }
       return;
     }
     if (self.allowedRemoteIds.indexOf(origin) >= 0) {
-      getOrCreateChannel(origin).onMessage(data);
+      getOrCreateChannel(origin, false).onMessage(data);
     } else {
       sendSignalingMessage(origin, 'chat-closed',
           ErrorModule.errors.P2P_CLIENT_DENIED);
@@ -186,7 +186,7 @@ const P2PClient = function(configuration, signalingChannel) {
       return Promise.reject(new ErrorModule.P2PError(
           ErrorModule.errors.P2P_CLIENT_NOT_ALLOWED));
     }
-    return Promise.resolve(getOrCreateChannel(remoteId).publish(stream));
+    return Promise.resolve(getOrCreateChannel(remoteId, true).publish(stream));
   };
 
   /**
@@ -208,7 +208,7 @@ const P2PClient = function(configuration, signalingChannel) {
       return Promise.reject(new ErrorModule.P2PError(
           ErrorModule.errors.P2P_CLIENT_NOT_ALLOWED));
     }
-    return Promise.resolve(getOrCreateChannel(remoteId).send(message));
+    return Promise.resolve(getOrCreateChannel(remoteId, true).send(message));
   };
 
   /**
@@ -263,13 +263,13 @@ const P2PClient = function(configuration, signalingChannel) {
     });
   };
 
-  const getOrCreateChannel = function(remoteId) {
+  const getOrCreateChannel = function(remoteId, isInitializer) {
     if (!channels.has(remoteId)) {
       // Construct an signaling sender/receiver for P2PPeerConnection.
       const signalingForChannel = Object.create(EventDispatcher);
       signalingForChannel.sendSignalingMessage = sendSignalingMessage;
       const pcc = new P2PPeerConnectionChannel(config, myId, remoteId,
-          signalingForChannel);
+          signalingForChannel, isInitializer);
       pcc.addEventListener('streamadded', (streamEvent)=>{
         self.dispatchEvent(streamEvent);
       });

src/sdk/p2p/peerconnection-channel.js

@@ -60,7 +60,7 @@ const sysInfo = Utils.sysInfo();
 class P2PPeerConnectionChannel extends EventDispatcher {
   // |signaling| is an object has a method |sendSignalingMessage|.
   /* eslint-disable-next-line require-jsdoc */
-  constructor(config, localId, remoteId, signaling) {
+  constructor(config, localId, remoteId, signaling, isInitializer) {
     super();
     this._config = config;
     this._localId = localId;
@@ -93,6 +93,10 @@ class P2PPeerConnectionChannel extends EventDispatcher {
     this._infoSent = false;
     this._disposed = false;
     this._createPeerConnection();
+    if (isInitializer) {
+      this._sendSignalingMessage(SignalingType.CLOSED);
+    }
+    this._sendSignalingMessage(SignalingType.UA, sysInfo);
   }
 
   /**
@@ -114,9 +118,7 @@ class P2PPeerConnectionChannel extends EventDispatcher {
           ErrorModule.errors.P2P_CLIENT_INVALID_STATE,
           'All tracks are ended.'));
     }
-    return Promise.all([this._sendClosedMsgIfNecessary(),
-      this._sendSysInfoIfNecessary(),
-      this._sendStreamInfo(stream)]).then(() => {
+    return this._sendStreamInfo(stream).then(() => {
       return new Promise((resolve, reject) => {
         // Replace |addStream| with PeerConnection.addTrack when all browsers are ready.
         for (const track of stream.mediaStream.getTracks()) {
@@ -159,14 +161,6 @@ class P2PPeerConnectionChannel extends EventDispatcher {
       this._createDataChannel(DataChannelLabel.MESSAGE);
     }
 
-    this._sendClosedMsgIfNecessary().catch((err) => {
-      Logger.debug('Failed to send closed message.' + err.message);
-    });
-
-    this._sendSysInfoIfNecessary().catch((err) => {
-      Logger.debug('Failed to send sysInfo.' + err.message);
-    });
-
     const dc = this._dataChannels.get(DataChannelLabel.MESSAGE);
     if (dc.readyState === 'open') {
       this._dataChannels.get(DataChannelLabel.MESSAGE).send(
@@ -242,7 +236,6 @@ class P2PPeerConnectionChannel extends EventDispatcher {
     switch (message.type) {
       case SignalingType.UA:
         this._handleRemoteCapability(message.data);
-        this._sendSysInfoIfNecessary();
         break;
       case SignalingType.TRACK_SOURCES:
         this._trackSourcesHandler(message.data);
@@ -803,23 +796,6 @@ class P2PPeerConnectionChannel extends EventDispatcher {
     ]);
   }
 
-
-  _sendSysInfoIfNecessary() {
-    if (this._infoSent) {
-      return Promise.resolve();
-    }
-    this._infoSent = true;
-    return this._sendSignalingMessage(SignalingType.UA, sysInfo);
-  }
-
-  _sendClosedMsgIfNecessary() {
-    if (this._pc.remoteDescription === null ||
-        this._pc.remoteDescription.sdp === '') {
-      return this._sendSignalingMessage(SignalingType.CLOSED);
-    }
-    return Promise.resolve();
-  }
-
   _handleRemoteCapability(ua) {
     if (ua.sdk && ua.sdk && ua.sdk.type === 'JavaScript' && ua.runtime &&
         ua.runtime.name === 'Firefox') {