Optimize Websocket compression for no context takeover requests

sdk/lib/io/websocket.dart

 // Copyright (c) 2013, the Dart project authors.  Please see the AUTHORS file
 // for details. All rights reserved. Use of this source code is governed by a
 // BSD-style license that can be found in the LICENSE file.
 
 part of dart.io;
 
 /**
  * WebSocket status codes used when closing a WebSocket connection.
  */
 abstract class WebSocketStatus {
@@ skipping 98 matching lines @@
 
   /// Returns default values for client compression request headers.
   String _createClientRequestHeader(HeaderValue requested, int size) {
     var info = "";
 
     // If responding to a valid request, specify size
     if (requested != null) {
       info = "; client_max_window_bits=$size";
     } else {
       // Client request. Specify default
-      info = "; client_max_window_bits";
+      if (clientMaxWindowBits == null) {
+        info = "; client_max_window_bits";
+      } else {
+        info = "; client_max_window_bits=$clientMaxWindowBits";
+      }
+      if (serverMaxWindowBits != null) {
+        info += "; server_max_window_bits=$serverMaxWindowBits";
+      }
     }
 
     return info;
   }
 
   /// Create a Compression Header. If [requested] is null or contains
   /// client request headers, returns Client compression request headers with
   /// default settings for `client_max_window_bits` header value.
   /// If [requested] contains server response headers this method returns
   /// a Server compression response header negotiating the max window bits
   /// for both client and server as requested server_max_window_bits value.
   /// This method returns a [_CompressionMaxWindowBits] object with the
   /// response headers and negotiated maxWindowBits value.
   _CompressionMaxWindowBits _createHeader([HeaderValue requested]) {
     var info = new _CompressionMaxWindowBits("", 0);
     if (!enabled) {
       return info;
     }
 
     info.headerValue = _WebSocketImpl.PER_MESSAGE_DEFLATE;
 
     if (clientNoContextTakeover &&
-        (requested != null &&
-            requested.parameters.containsKey(_clientNoContextTakeover))) {
+        (requested == null || (requested != null &&
+            requested.parameters.containsKey(_clientNoContextTakeover)))) {
       info.headerValue += "; client_no_context_takeover";
     }
 
     if (serverNoContextTakeover &&
-        (requested != null &&
-            requested.parameters.containsKey(_serverNoContextTakeover))) {
+        (requested == null || (requested != null &&
+            requested.parameters.containsKey(_serverNoContextTakeover)))) {
       info.headerValue += "; server_no_context_takeover";
     }
 
     var headerList = _createServerResponseHeader(requested);
     info.headerValue += headerList.headerValue;
     info.maxWindowBits = headerList.maxWindowBits;
 
     info.headerValue +=
         _createClientRequestHeader(requested, info.maxWindowBits);
 
@@ skipping 234 matching lines @@
   Future addStream(Stream stream);
 }
 
 class WebSocketException implements IOException {
   final String message;
 
   const WebSocketException([this.message = ""]);
 
   String toString() => "WebSocketException: $message";
 }