Implement the client-side framework for extensions.

lib/websocket/driver/client.js

@@ -59,10 +59,18 @@ var instance = {
     if (!this._http.isComplete()) return;
 
     this._validateHandshake();
+    if (this.readyState === 3) return;
+
+    this._extensions.activate(this.headers['sec-websocket-extensions']);
+    this._open();
     this.parse(this._http.body);
   },
 
   _handshakeRequest: function() {
+    var extensions = this._extensions.generateOffer();
+    if (extensions)
+      this._headers.set('Sec-WebSocket-Extensions', extensions);
+
     var start   = 'GET ' + this._pathname + ' HTTP/1.1',
         headers = [start, this._headers.toString(), ''];
 
@@ -110,8 +118,6 @@ var instance = {
       else
         this.protocol = protocol;
     }
-
-    this._open();
   }
 };
 

lib/websocket/driver/hybi.js

@@ -227,11 +227,11 @@ var instance = {
     }
 
     var length = frame.length,
-        masked = frame.masked,
         header = (length <= 125) ? 2 : (length <= 65535 ? 4 : 10),
-        offset = header + (masked ? 4 : 0),
+        offset = header + (frame.masked ? 4 : 0),
         buffer = new Buffer(offset + length),
-        BYTE   = this.BYTE;
+        BYTE   = this.BYTE,
+        masked = frame.masked ? this.MASK : 0;
 
     buffer[0] = (frame.final ? this.FIN : 0) |
                 (frame.rsv1 ? this.RSV1 : 0) |
@@ -268,7 +268,7 @@ var instance = {
   },
 
   _handshakeResponse: function() {
-    var extensions = this._extensions.activate(this._request.headers['sec-websocket-extensions']);
+    var extensions = this._extensions.generateResponse(this._request.headers['sec-websocket-extensions']);
     if (extensions) this._headers.set('Sec-WebSocket-Extensions', extensions);
 
     var start   = 'HTTP/1.1 101 Switching Protocols',

lib/websocket/driver/hybi/extensions.js

@@ -13,6 +13,8 @@ var Extensions = function(driver) {
   this._byName   = {};
   this._inOrder  = [];
   this._sessions = [];
+
+  this._rsv1 = this._rsv2 = this._rsv3 = false;
 };
 
 var instance = {
@@ -30,28 +32,68 @@ var instance = {
     this._inOrder.push(extension);
   },
 
-  activate: function(header) {
-    if (header === undefined) return;
+  generateOffer: function() {
+    var sessions = [],
+        offer    = [],
+        index    = {};
 
+    this._inOrder.forEach(function(ext) {
+      var session = ext.createClientSession(this);
+      if (!session) return;
+
+      sessions.push(session);
+      index[ext.name] = {ext: ext, session: session};
+
+      var offers = session.generateOffers();
+      offers = offers ? [].concat(offers) : [];
+
+      offers.forEach(function(off) {
+        offer.push(this._serializeParams(ext.name, off));
+      }, this);
+    }, this);
+
+    this._sessions = sessions;
+    this._index    = index;
+
+    return offer.length > 0 ? offer.join(', ') : null;
+  },
+
+  activate: function(header) {
+    var responses = this._parseHeader(header),
+        active    = [];
+
+    responses.forEach(function(response) {
+      var record  = this._index[response.name],
+          ext     = record.ext,
+          session = record.session;
+
+      if (this._reserved(ext)) return;
+      this._reserve(ext);
+
+      session.activate(response.params);
+      active.push(session);
+    }, this);
+
+    this._sessions = this._sessions.filter(function(session) {
+      return active.indexOf(session) >= 0;
+    });
+  },
+
+  generateResponse: function(header) {
     var offers   = this._parseHeader(header),
         sessions = [],
         response = [];
 
-    this._rsv1 = this._rsv2 = this._rsv3 = false;
-
     offers.forEach(function(offer) {
       var ext = this._byName[offer.name];
-      if (!ext || (this._rsv1 && ext.rsv1) || (this._rsv2 && ext.rsv2) || (this._rsv3 && ext.rsv3)) return;
+      if (!ext || this._reserved(ext)) return;
 
       var session = ext && ext.createServerSession(this, offer.params);
       if (!session) return;
 
-      this._rsv1 = this._rsv1 || ext.rsv1;
-      this._rsv2 = this._rsv2 || ext.rsv2;
-      this._rsv3 = this._rsv3 || ext.rsv3;
-
+      this._reserve(ext);
       sessions.push(session);
-      response.push(this._serializeParams(offer.name, session.getResponseParams()));
+      response.push(this._serializeParams(offer.name, session.generateResponse()));
     }, this);
 
     this._sessions = sessions;
@@ -62,7 +104,7 @@ var instance = {
     var sessions = this._sessions.slice();
 
     var pipe = function(msg) {
-      var session = sessions.shift();
+      var session = sessions.pop();
       if (!session) return callback.call(context, msg);
       session.processIncomingMessage(msg, pipe);
     };
@@ -73,7 +115,7 @@ var instance = {
     var sessions = this._sessions.slice();
 
     var pipe = function(msg) {
-      var session = sessions.pop();
+      var session = sessions.shift();
       if (!session) return callback.call(context, msg);
       session.processOutgoingMessage(msg, pipe);
     };
@@ -88,7 +130,19 @@ var instance = {
     this._driver._fail(type, message);
   },
 
+  _reserve: function(ext) {
+    this._rsv1 = this._rsv1 || ext.rsv1;
+    this._rsv2 = this._rsv2 || ext.rsv2;
+    this._rsv3 = this._rsv3 || ext.rsv3;
+  },
+
+  _reserved: function(ext) {
+    return (this._rsv1 && ext.rsv1) || (this._rsv2 && ext.rsv2) || (this._rsv3 && ext.rsv3);
+  },
+
   _parseHeader: function(header) {
+    if (header === undefined) return [];
+
     if (!EXT_LIST.test(header))
       throw new Error('Not a valid Sec-WebSocket-Extensions header: ' + header);