Improve WebSocket interface by making it implement StreamSink.

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;
 
 /**
  * Web socket status codes used when closing a web socket connection.
  */
 abstract class WebSocketStatus {
@@ skipping 62 matching lines @@
     return _WebSocketTransformerImpl._isUpgradeRequest(request);
   }
 }
 
 
 /**
  * A client or server web socket connection. The stream exposes the
  * messages received. A text message will be of type [:String:] and a
  * binary message will be of type [:List<int>:].
  */
-abstract class WebSocket implements Stream {
+abstract class WebSocket implements Stream, StreamSink {
   /**
    * Possible states of the connection.
    */
   static const int CONNECTING = 0;
   static const int OPEN = 1;
   static const int CLOSING = 2;
   static const int CLOSED = 3;
 
   /**
    * Create a new web socket connection. The URL supplied in [url]
@@ skipping 30 matching lines @@
    */
   int get closeCode;
 
   /**
    * The close reason set when the web socket connection is closed. If
    * there is no close reason available this property will be [:null:]
    */
   String get closeReason;
 
   /**
-   * Closes the web socket connection.
+   * Closes the web socket connection. Set the optional [code] and [reason]
+   * arguments to send close information to the remote peer. If they are
+   * omitted, the peer will see [WebSocketStatus.NO_STATUS_RECEIVED] code
+   * with no reason.
    */
-  void close([int code, String reason]);
+  Future close([int code, String reason]);
 
   /**
    * Sends data on the web socket connection. The data in [data] must
    * be either a [:String:], or a [:List<int>:] holding bytes.
    */
-  void send(data);
+  void add(data);
+
+  /**
+   * Sends data from a stream on web socket connection. Each data event from
+   * [stream] will be send as a single WebSocket frame. The data from [stream]
+   * must be either [:String:]s, or [:List<int>:]s holding bytes.
+   */
+  Future addStream(Stream stream);
 }
 
 
 class WebSocketException implements Exception {
   const WebSocketException([String this.message = ""]);
   String toString() => "WebSocketException: $message";
   final String message;
 }