Bring in latest dart:io WebSocket code.

lib/src/web_socket.dart

 // Copyright (c) 2014, 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.
 
 library http_parser.web_socket;
 
 import 'dart:async';
-import 'dart:convert';
-import 'dart:math';
-import 'dart:typed_data';
 
 import 'package:crypto/crypto.dart';
 
-import 'bytes_builder.dart';
+import 'copy/web_socket_impl.dart';
 
 /// An implementation of the WebSocket protocol that's not specific to "dart:io"
 /// or to any particular HTTP API.
 ///
 /// Because this is HTTP-API-agnostic, it doesn't handle the initial [WebSocket
 /// handshake][]. This needs to be handled manually by the user of the code.
 /// Once that's been done, [new CompatibleWebSocket] can be called with the
 /// underlying socket and it will handle the remainder of the protocol.
 ///
 /// [WebSocket handshake]: https://tools.ietf.org/html/rfc6455#section-4
@@ skipping 30 matching lines @@
   /// the [initial handshake].
   ///
   /// The return value should be sent back to the client in a
   /// `Sec-WebSocket-Accept` header.
   ///
   /// [initial handshake]: https://tools.ietf.org/html/rfc6455#section-4.2.2
   static String signKey(String key) {
     var hash = new SHA1();
     // We use [codeUnits] here rather than UTF-8-decoding the string because
     // [key] is expected to be base64 encoded, and so will be pure ASCII.
-    hash.add((key + _webSocketGUID).codeUnits);
+    hash.add((key + webSocketGUID).codeUnits);
     return CryptoUtils.bytesToBase64(hash.close());
   }
 
   /// Creates a new WebSocket handling messaging across an existing socket.
   ///
   /// Because this is HTTP-API-agnostic, the initial [WebSocket handshake][]
   /// must have already been completed on the socket before this is called.
   ///
   /// If [stream] is also a [StreamSink] (for example, if it's a "dart:io"
   /// `Socket`), it will be used for both sending and receiving data. Otherwise,
   /// it will be used for receiving data and [sink] will be used for sending it.
   ///
+  /// [protocol] should be the protocol negotiated by this handshake, if any.
+  ///
   /// If this is a WebSocket server, [serverSide] should be `true` (the
   /// default); if it's a client, [serverSide] should be `false`.
   ///
   /// [WebSocket handshake]: https://tools.ietf.org/html/rfc6455#section-4
   factory CompatibleWebSocket(Stream<List<int>> stream,
-        {StreamSink<List<int>> sink, bool serverSide: true}) {
+        {StreamSink<List<int>> sink, String protocol, bool serverSide: true}) {
     if (sink == null) {
       if (stream is! StreamSink) {
         throw new ArgumentError("If stream isn't also a StreamSink, sink must "
             "be passed explicitly.");
       }
       sink = stream as StreamSink;
     }
 
-    return new _WebSocketImpl._fromSocket(stream, sink, serverSide);
+    return new WebSocketImpl.fromSocket(stream, sink, protocol, serverSide);
   }
 
   /// Closes the web socket connection.
   ///
   /// [closeCode] and [closeReason] are the [close code][] and [reason][] sent
   /// to the remote peer, respectively. If they are omitted, the peer will see
   /// a "no status received" code with no reason.
   ///
   /// [close code]: https://tools.ietf.org/html/rfc6455#section-7.1.5
   /// [reason]: https://tools.ietf.org/html/rfc6455#section-7.1.6
   Future close([int closeCode, String closeReason]);
 }
 
 /// An exception thrown by [CompatibleWebSocket].
 class CompatibleWebSocketException implements Exception {
   final String message;
 
   CompatibleWebSocketException([this.message]);
 
   String toString() => message == null
       ? "CompatibleWebSocketException" :
         "CompatibleWebSocketException: $message";
 }
-
-// The following code is copied from sdk/lib/io/websocket_impl.dart. The
-// "dart:io" implementation isn't used directly both to support non-"dart:io"
-// applications, and because it's incompatible with non-"dart:io" HTTP requests
-// (issue 18172).
-//
-// Because it's copied directly, only modifications necessary to support the
-// desired public API and to remove "dart:io" dependencies have been made.
-
-/**
- * Web socket status codes used when closing a web socket connection.
- */
-abstract class _WebSocketStatus {
-  static const int NORMAL_CLOSURE = 1000;
-  static const int GOING_AWAY = 1001;
-  static const int PROTOCOL_ERROR = 1002;
-  static const int UNSUPPORTED_DATA = 1003;
-  static const int RESERVED_1004  = 1004;
-  static const int NO_STATUS_RECEIVED = 1005;
-  static const int ABNORMAL_CLOSURE = 1006;
-  static const int INVALID_FRAME_PAYLOAD_DATA = 1007;
-  static const int POLICY_VIOLATION = 1008;
-  static const int MESSAGE_TOO_BIG = 1009;
-  static const int MISSING_MANDATORY_EXTENSION = 1010;
-  static const int INTERNAL_SERVER_ERROR = 1011;
-  static const int RESERVED_1015 = 1015;
-}
-
-abstract class _WebSocketState {
-  static const int CONNECTING = 0;
-  static const int OPEN = 1;
-  static const int CLOSING = 2;
-  static const int CLOSED = 3;
-}
-
-const String _webSocketGUID = "258EAFA5-E914-47DA-95CA-C5AB0DC85B11";
-
-final _random = new Random();
-
-// Matches _WebSocketOpcode.
-class _WebSocketMessageType {
-  static const int NONE = 0;
-  static const int TEXT = 1;
-  static const int BINARY = 2;
-}
-
-
-class _WebSocketOpcode {
-  static const int CONTINUATION = 0;
-  static const int TEXT = 1;
-  static const int BINARY = 2;
-  static const int RESERVED_3 = 3;
-  static const int RESERVED_4 = 4;
-  static const int RESERVED_5 = 5;
-  static const int RESERVED_6 = 6;
-  static const int RESERVED_7 = 7;
-  static const int CLOSE = 8;
-  static const int PING = 9;
-  static const int PONG = 10;
-  static const int RESERVED_B = 11;
-  static const int RESERVED_C = 12;
-  static const int RESERVED_D = 13;
-  static const int RESERVED_E = 14;
-  static const int RESERVED_F = 15;
-}
-
-/**
- * The web socket protocol transformer handles the protocol byte stream
- * which is supplied through the [:handleData:]. As the protocol is processed,
- * it'll output frame data as either a List<int> or String.
- *
- * Important infomation about usage: Be sure you use cancelOnError, so the
- * socket will be closed when the processer encounter an error. Not using it
- * will lead to undefined behaviour.
- */
-// TODO(ajohnsen): make this transformer reusable?
-class _WebSocketProtocolTransformer implements StreamTransformer, EventSink {
-  static const int START = 0;
-  static const int LEN_FIRST = 1;
-  static const int LEN_REST = 2;
-  static const int MASK = 3;
-  static const int PAYLOAD = 4;
-  static const int CLOSED = 5;
-  static const int FAILURE = 6;
-
-  int _state = START;
-  bool _fin = false;
-  int _opcode = -1;
-  int _len = -1;
-  bool _masked = false;
-  int _remainingLenBytes = -1;
-  int _remainingMaskingKeyBytes = 4;
-  int _remainingPayloadBytes = -1;
-  int _unmaskingIndex = 0;
-  int _currentMessageType = _WebSocketMessageType.NONE;
-  int closeCode = _WebSocketStatus.NO_STATUS_RECEIVED;
-  String closeReason = "";
-
-  EventSink _eventSink;
-
-  final bool _serverSide;
-  final List _maskingBytes = new List(4);
-  final BytesBuilder _payload = new BytesBuilder(copy: false);
-
-  _WebSocketProtocolTransformer([this._serverSide = false]);
-
-  Stream bind(Stream stream) {
-    return new Stream.eventTransformed(
-        stream,
-        (EventSink eventSink) {
-          if (_eventSink != null) {
-            throw new StateError("WebSocket transformer already used.");
-          }
-          _eventSink = eventSink;
-          return this;
-        });
-  }
-
-  void addError(Object error, [StackTrace stackTrace]) =>
-      _eventSink.addError(error, stackTrace);
-
-  void close() => _eventSink.close();
-
-  /**
-   * Process data received from the underlying communication channel.
-   */
-  void add(Uint8List buffer) {
-    int count = buffer.length;
-    int index = 0;
-    int lastIndex = count;
-    if (_state == CLOSED) {
-      throw new CompatibleWebSocketException("Data on closed connection");
-    }
-    if (_state == FAILURE) {
-      throw new CompatibleWebSocketException("Data on failed connection");
-    }
-    while ((index < lastIndex) && _state != CLOSED && _state != FAILURE) {
-      int byte = buffer[index];
-      if (_state <= LEN_REST) {
-        if (_state == START) {
-          _fin = (byte & 0x80) != 0;
-          if ((byte & 0x70) != 0) {
-            // The RSV1, RSV2 bits RSV3 must be all zero.
-            throw new CompatibleWebSocketException("Protocol error");
-          }
-          _opcode = (byte & 0xF);
-          if (_opcode <= _WebSocketOpcode.BINARY) {
-            if (_opcode == _WebSocketOpcode.CONTINUATION) {
-              if (_currentMessageType == _WebSocketMessageType.NONE) {
-                throw new CompatibleWebSocketException("Protocol error");
-              }
-            } else {
-              assert(_opcode == _WebSocketOpcode.TEXT ||
-                     _opcode == _WebSocketOpcode.BINARY);
-              if (_currentMessageType != _WebSocketMessageType.NONE) {
-                throw new CompatibleWebSocketException("Protocol error");
-              }
-              _currentMessageType = _opcode;
-            }
-          } else if (_opcode >= _WebSocketOpcode.CLOSE &&
-                     _opcode <= _WebSocketOpcode.PONG) {
-            // Control frames cannot be fragmented.
-            if (!_fin) throw new CompatibleWebSocketException("Protocol error");
-          } else {
-            throw new CompatibleWebSocketException("Protocol error");
-          }
-          _state = LEN_FIRST;
-        } else if (_state == LEN_FIRST) {
-          _masked = (byte & 0x80) != 0;
-          _len = byte & 0x7F;
-          if (_isControlFrame() && _len > 125) {
-            throw new CompatibleWebSocketException("Protocol error");
-          }
-          if (_len == 126) {
-            _len = 0;
-            _remainingLenBytes = 2;
-            _state = LEN_REST;
-          } else if (_len == 127) {
-            _len = 0;
-            _remainingLenBytes = 8;
-            _state = LEN_REST;
-          } else {
-            assert(_len < 126);
-            _lengthDone();
-          }
-        } else {
-          assert(_state == LEN_REST);
-          _len = _len << 8 | byte;
-          _remainingLenBytes--;
-          if (_remainingLenBytes == 0) {
-            _lengthDone();
-          }
-        }
-      } else {
-        if (_state == MASK) {
-          _maskingBytes[4 - _remainingMaskingKeyBytes--] = byte;
-          if (_remainingMaskingKeyBytes == 0) {
-            _maskDone();
-          }
-        } else {
-          assert(_state == PAYLOAD);
-          // The payload is not handled one byte at a time but in blocks.
-          int payloadLength = min(lastIndex - index, _remainingPayloadBytes);
-          _remainingPayloadBytes -= payloadLength;
-          // Unmask payload if masked.
-          if (_masked) {
-            _unmask(index, payloadLength, buffer);
-          }
-          // Control frame and data frame share _payloads.
-          _payload.add(
-              new Uint8List.view(buffer.buffer, index, payloadLength));
-          index += payloadLength;
-          if (_isControlFrame()) {
-            if (_remainingPayloadBytes == 0) _controlFrameEnd();
-          } else {
-            if (_currentMessageType != _WebSocketMessageType.TEXT &&
-                _currentMessageType != _WebSocketMessageType.BINARY) {
-                throw new CompatibleWebSocketException("Protocol error");
-            }
-            if (_remainingPayloadBytes == 0) _messageFrameEnd();
-          }
-
-          // Hack - as we always do index++ below.
-          index--;
-        }
-      }
-
-      // Move to the next byte.
-      index++;
-    }
-  }
-
-  void _unmask(int index, int length, Uint8List buffer) {
-    const int BLOCK_SIZE = 16;
-    // Skip Int32x4-version if message is small.
-    if (length >= BLOCK_SIZE) {
-      // Start by aligning to 16 bytes.
-      final int startOffset = BLOCK_SIZE - (index & 15);
-      final int end = index + startOffset;
-      for (int i = index; i < end; i++) {
-        buffer[i] ^= _maskingBytes[_unmaskingIndex++ & 3];
-      }
-      index += startOffset;
-      length -= startOffset;
-      final int blockCount = length ~/ BLOCK_SIZE;
-      if (blockCount > 0) {
-        // Create mask block.
-        int mask = 0;
-        for (int i = 3; i >= 0; i--) {
-          mask = (mask << 8) | _maskingBytes[(_unmaskingIndex + i) & 3];
-        }
-        Int32x4 blockMask = new Int32x4(mask, mask, mask, mask);
-        Int32x4List blockBuffer = new Int32x4List.view(
-            buffer.buffer, index, blockCount);
-        for (int i = 0; i < blockBuffer.length; i++) {
-          blockBuffer[i] ^= blockMask;
-        }
-        final int bytes = blockCount * BLOCK_SIZE;
-        index += bytes;
-        length -= bytes;
-      }
-    }
-    // Handle end.
-    final int end = index + length;
-    for (int i = index; i < end; i++) {
-      buffer[i] ^= _maskingBytes[_unmaskingIndex++ & 3];
-    }
-  }
-
-  void _lengthDone() {
-    if (_masked) {
-      if (!_serverSide) {
-        throw new CompatibleWebSocketException(
-            "Received masked frame from server");
-      }
-      _state = MASK;
-    } else {
-      if (_serverSide) {
-        throw new CompatibleWebSocketException(
-            "Received unmasked frame from client");
-      }
-      _remainingPayloadBytes = _len;
-      _startPayload();
-    }
-  }
-
-  void _maskDone() {
-    _remainingPayloadBytes = _len;
-    _startPayload();
-  }
-
-  void _startPayload() {
-    // If there is no actual payload perform perform callbacks without
-    // going through the PAYLOAD state.
-    if (_remainingPayloadBytes == 0) {
-      if (_isControlFrame()) {
-        switch (_opcode) {
-          case _WebSocketOpcode.CLOSE:
-            _state = CLOSED;
-            _eventSink.close();
-            break;
-          case _WebSocketOpcode.PING:
-            _eventSink.add(new _WebSocketPing());
-            break;
-          case _WebSocketOpcode.PONG:
-            _eventSink.add(new _WebSocketPong());
-            break;
-        }
-        _prepareForNextFrame();
-      } else {
-        _messageFrameEnd();
-      }
-    } else {
-      _state = PAYLOAD;
-    }
-  }
-
-  void _messageFrameEnd() {
-    if (_fin) {
-      switch (_currentMessageType) {
-        case _WebSocketMessageType.TEXT:
-          _eventSink.add(UTF8.decode(_payload.takeBytes()));
-          break;
-        case _WebSocketMessageType.BINARY:
-          _eventSink.add(_payload.takeBytes());
-          break;
-      }
-      _currentMessageType = _WebSocketMessageType.NONE;
-    }
-    _prepareForNextFrame();
-  }
-
-  void _controlFrameEnd() {
-    switch (_opcode) {
-      case _WebSocketOpcode.CLOSE:
-        closeCode = _WebSocketStatus.NO_STATUS_RECEIVED;
-        var payload = _payload.takeBytes();
-        if (payload.length > 0) {
-          if (payload.length == 1) {
-            throw new CompatibleWebSocketException("Protocol error");
-          }
-          closeCode = payload[0] << 8 | payload[1];
-          if (closeCode == _WebSocketStatus.NO_STATUS_RECEIVED) {
-            throw new CompatibleWebSocketException("Protocol error");
-          }
-          if (payload.length > 2) {
-            closeReason = UTF8.decode(payload.sublist(2));
-          }
-        }
-        _state = CLOSED;
-        _eventSink.close();
-        break;
-
-      case _WebSocketOpcode.PING:
-        _eventSink.add(new _WebSocketPing(_payload.takeBytes()));
-        break;
-
-      case _WebSocketOpcode.PONG:
-        _eventSink.add(new _WebSocketPong(_payload.takeBytes()));
-        break;
-    }
-    _prepareForNextFrame();
-  }
-
-  bool _isControlFrame() {
-    return _opcode == _WebSocketOpcode.CLOSE ||
-           _opcode == _WebSocketOpcode.PING ||
-           _opcode == _WebSocketOpcode.PONG;
-  }
-
-  void _prepareForNextFrame() {
-    if (_state != CLOSED && _state != FAILURE) _state = START;
-    _fin = false;
-    _opcode = -1;
-    _len = -1;
-    _remainingLenBytes = -1;
-    _remainingMaskingKeyBytes = 4;
-    _remainingPayloadBytes = -1;
-    _unmaskingIndex = 0;
-  }
-}
-
-
-class _WebSocketPing {
-  final List<int> payload;
-  _WebSocketPing([this.payload = null]);
-}
-
-
-class _WebSocketPong {
-  final List<int> payload;
-  _WebSocketPong([this.payload = null]);
-}
-
-// TODO(ajohnsen): Make this transformer reusable.
-class _WebSocketOutgoingTransformer implements StreamTransformer, EventSink {
-  final _WebSocketImpl webSocket;
-  EventSink _eventSink;
-
-  _WebSocketOutgoingTransformer(this.webSocket);
-
-  Stream bind(Stream stream) {
-    return new Stream.eventTransformed(
-        stream,
-        (EventSink eventSink) {
-          if (_eventSink != null) {
-            throw new StateError("WebSocket transformer already used");
-          }
-          _eventSink = eventSink;
-          return this;
-        });
-  }
-
-  void add(message) {
-    if (message is _WebSocketPong) {
-      addFrame(_WebSocketOpcode.PONG, message.payload);
-      return;
-    }
-    if (message is _WebSocketPing) {
-      addFrame(_WebSocketOpcode.PING, message.payload);
-      return;
-    }
-    List<int> data;
-    int opcode;
-    if (message != null) {
-      if (message is String) {
-        opcode = _WebSocketOpcode.TEXT;
-        data = UTF8.encode(message);
-      } else {
-        if (message is !List<int>) {
-          throw new ArgumentError(message);
-        }
-        opcode = _WebSocketOpcode.BINARY;
-        data = message;
-      }
-    } else {
-      opcode = _WebSocketOpcode.TEXT;
-    }
-    addFrame(opcode, data);
-  }
-
-  void addError(Object error, [StackTrace stackTrace]) =>
-      _eventSink.addError(error, stackTrace);
-
-  void close() {
-    int code = webSocket._outCloseCode;
-    String reason = webSocket._outCloseReason;
-    List<int> data;
-    if (code != null) {
-      data = new List<int>();
-      data.add((code >> 8) & 0xFF);
-      data.add(code & 0xFF);
-      if (reason != null) {
-        data.addAll(UTF8.encode(reason));
-      }
-    }
-    addFrame(_WebSocketOpcode.CLOSE, data);
-    _eventSink.close();
-  }
-
-  void addFrame(int opcode, List<int> data) =>
-      createFrame(opcode, data, webSocket._serverSide).forEach(_eventSink.add);
-
-  static Iterable createFrame(int opcode, List<int> data, bool serverSide) {
-    bool mask = !serverSide;  // Masking not implemented for server.
-    int dataLength = data == null ? 0 : data.length;
-    // Determine the header size.
-    int headerSize = (mask) ? 6 : 2;
-    if (dataLength > 65535) {
-      headerSize += 8;
-    } else if (dataLength > 125) {
-      headerSize += 2;
-    }
-    Uint8List header = new Uint8List(headerSize);
-    int index = 0;
-    // Set FIN and opcode.
-    header[index++] = 0x80 | opcode;
-    // Determine size and position of length field.
-    int lengthBytes = 1;
-    if (dataLength > 65535) {
-      header[index++] = 127;
-      lengthBytes = 8;
-    } else if (dataLength > 125) {
-      header[index++] = 126;
-      lengthBytes = 2;
-    }
-    // Write the length in network byte order into the header.
-    for (int i = 0; i < lengthBytes; i++) {
-      header[index++] = dataLength >> (((lengthBytes - 1) - i) * 8) & 0xFF;
-    }
-    if (mask) {
-      header[1] |= 1 << 7;
-      var maskBytes = [_random.nextInt(256), _random.nextInt(256),
-          _random.nextInt(256), _random.nextInt(256)];
-      header.setRange(index, index + 4, maskBytes);
-      index += 4;
-      if (data != null) {
-        Uint8List list;
-        // If this is a text message just do the masking inside the
-        // encoded data.
-        if (opcode == _WebSocketOpcode.TEXT && data is Uint8List) {
-          list = data;
-        } else {
-          if (data is Uint8List) {
-            list = new Uint8List.fromList(data);
-          } else {
-            list = new Uint8List(data.length);
-            for (int i = 0; i < data.length; i++) {
-              if (data[i] < 0 || 255 < data[i]) {
-                throw new ArgumentError(
-                    "List element is not a byte value "
-                    "(value ${data[i]} at index $i)");
-              }
-              list[i] = data[i];
-            }
-          }
-        }
-        const int BLOCK_SIZE = 16;
-        int blockCount = list.length ~/ BLOCK_SIZE;
-        if (blockCount > 0) {
-          // Create mask block.
-          int mask = 0;
-          for (int i = 3; i >= 0; i--) {
-            mask = (mask << 8) | maskBytes[i];
-          }
-          Int32x4 blockMask = new Int32x4(mask, mask, mask, mask);
-          Int32x4List blockBuffer = new Int32x4List.view(
-              list.buffer, 0, blockCount);
-          for (int i = 0; i < blockBuffer.length; i++) {
-            blockBuffer[i] ^= blockMask;
-          }
-        }
-        // Handle end.
-        for (int i = blockCount * BLOCK_SIZE; i < list.length; i++) {
-          list[i] ^= maskBytes[i & 3];
-        }
-        data = list;
-      }
-    }
-    assert(index == headerSize);
-    if (data == null) {
-      return [header];
-    } else {
-      return [header, data];
-    }
-  }
-}
-
-
-class _WebSocketConsumer implements StreamConsumer {
-  final _WebSocketImpl webSocket;
-  final StreamSink<List<int>> sink;
-  StreamController _controller;
-  StreamSubscription _subscription;
-  bool _issuedPause = false;
-  bool _closed = false;
-  Completer _closeCompleter = new Completer();
-  Completer _completer;
-
-  _WebSocketConsumer(this.webSocket, this.sink);
-
-  void _onListen() {
-    if (_subscription != null) {
-      _subscription.cancel();
-    }
-  }
-
-  void _onPause() {
-    if (_subscription != null) {
-      _subscription.pause();
-    } else {
-      _issuedPause = true;
-    }
-  }
-
-  void _onResume() {
-    if (_subscription != null) {
-      _subscription.resume();
-    } else {
-      _issuedPause = false;
-    }
-  }
-
-  void _cancel() {
-    if (_subscription != null) {
-      var subscription = _subscription;
-      _subscription = null;
-      subscription.cancel();
-    }
-  }
-
-  _ensureController() {
-    if (_controller != null) return;
-    _controller = new StreamController(sync: true,
-                                       onPause: _onPause,
-                                       onResume: _onResume,
-                                       onCancel: _onListen);
-    var stream = _controller.stream.transform(
-        new _WebSocketOutgoingTransformer(webSocket));
-    sink.addStream(stream)
-        .then((_) {
-          _done();
-          _closeCompleter.complete(webSocket);
-        }, onError: (error, StackTrace stackTrace) {
-          _closed = true;
-          _cancel();
-          if (error is ArgumentError) {
-            if (!_done(error, stackTrace)) {
-              _closeCompleter.completeError(error, stackTrace);
-            }
-          } else {
-            _done();
-            _closeCompleter.complete(webSocket);
-          }
-        });
-  }
-
-  bool _done([error, StackTrace stackTrace]) {
-    if (_completer == null) return false;
-    if (error != null) {
-      _completer.completeError(error, stackTrace);
-    } else {
-      _completer.complete(webSocket);
-    }
-    _completer = null;
-    return true;
-  }
-
-  Future addStream(var stream) {
-    if (_closed) {
-      stream.listen(null).cancel();
-      return new Future.value(webSocket);
-    }
-    _ensureController();
-    _completer = new Completer();
-    _subscription = stream.listen(
-        (data) {
-          _controller.add(data);
-        },
-        onDone: _done,
-        onError: _done,
-        cancelOnError: true);
-    if (_issuedPause) {
-      _subscription.pause();
-      _issuedPause = false;
-    }
-    return _completer.future;
-  }
-
-  Future close() {
-    _ensureController();
-    Future closeSocket() {
-      return sink.close().catchError((_) {}).then((_) => webSocket);
-    }
-    _controller.close();
-    return _closeCompleter.future.then((_) => closeSocket());
-  }
-
-  void add(data) {
-    if (_closed) return;
-    _ensureController();
-    _controller.add(data);
-  }
-
-  void closeSocket() {
-    _closed = true;
-    _cancel();
-    close();
-  }
-}
-
-
-class _WebSocketImpl extends Stream implements CompatibleWebSocket {
-  StreamController _controller;
-  StreamSubscription _subscription;
-  StreamController _sink;
-
-  final bool _serverSide;
-  int _readyState = _WebSocketState.CONNECTING;
-  bool _writeClosed = false;
-  int _closeCode;
-  String _closeReason;
-  Duration _pingInterval;
-  Timer _pingTimer;
-  _WebSocketConsumer _consumer;
-
-  int _outCloseCode;
-  String _outCloseReason;
-  Timer _closeTimer;
-
-  _WebSocketImpl._fromSocket(Stream<List<int>> stream,
-      StreamSink<List<int>> sink, [this._serverSide = false]) {
-    _consumer = new _WebSocketConsumer(this, sink);
-    _sink = new StreamController();
-    _sink.stream.pipe(_consumer);
-    _readyState = _WebSocketState.OPEN;
-
-    var transformer = new _WebSocketProtocolTransformer(_serverSide);
-    _subscription = stream.transform(transformer).listen(
-        (data) {
-          if (data is _WebSocketPing) {
-            if (!_writeClosed) _consumer.add(new _WebSocketPong(data.payload));
-          } else if (data is _WebSocketPong) {
-            // Simply set pingInterval, as it'll cancel any timers.
-            pingInterval = _pingInterval;
-          } else {
-            _controller.add(data);
-          }
-        },
-        onError: (error) {
-          if (_closeTimer != null) _closeTimer.cancel();
-          if (error is FormatException) {
-            _close(_WebSocketStatus.INVALID_FRAME_PAYLOAD_DATA);
-          } else {
-            _close(_WebSocketStatus.PROTOCOL_ERROR);
-          }
-          _controller.close();
-        },
-        onDone: () {
-          if (_closeTimer != null) _closeTimer.cancel();
-          if (_readyState == _WebSocketState.OPEN) {
-            _readyState = _WebSocketState.CLOSING;
-            if (!_isReservedStatusCode(transformer.closeCode)) {
-              _close(transformer.closeCode);
-            } else {
-              _close();
-            }
-            _readyState = _WebSocketState.CLOSED;
-          }
-          _closeCode = transformer.closeCode;
-          _closeReason = transformer.closeReason;
-          _controller.close();
-        },
-        cancelOnError: true);
-    _subscription.pause();
-    _controller = new StreamController(sync: true,
-                                       onListen: _subscription.resume,
-                                       onPause: _subscription.pause,
-                                       onResume: _subscription.resume);
-  }
-
-  StreamSubscription listen(void onData(message),
-                            {Function onError,
-                             void onDone(),
-                             bool cancelOnError}) {
-    return _controller.stream.listen(onData,
-                                     onError: onError,
-                                     onDone: onDone,
-                                     cancelOnError: cancelOnError);
-  }
-
-  Duration get pingInterval => _pingInterval;
-
-  void set pingInterval(Duration interval) {
-    if (_writeClosed) return;
-    if (_pingTimer != null) _pingTimer.cancel();
-    _pingInterval = interval;
-
-    if (_pingInterval == null) return;
-
-    _pingTimer = new Timer(_pingInterval, () {
-      if (_writeClosed) return;
-      _consumer.add(new _WebSocketPing());
-      _pingTimer = new Timer(_pingInterval, () {
-        // No pong received.
-        _close(_WebSocketStatus.GOING_AWAY);
-      });
-    });
-  }
-
-  int get closeCode => _closeCode;
-  String get closeReason => _closeReason;
-
-  void add(data) => _sink.add(data);
-  void addError(error, [StackTrace stackTrace]) =>
-      _sink.addError(error, stackTrace);
-  Future addStream(Stream stream) => _sink.addStream(stream);
-  Future get done => _sink.done;
-
-  Future close([int code, String reason]) {
-    if (_isReservedStatusCode(code)) {
-      throw new CompatibleWebSocketException("Reserved status code $code");
-    }
-    if (_outCloseCode == null) {
-      _outCloseCode = code;
-      _outCloseReason = reason;
-    }
-    if (_closeTimer == null && !_controller.isClosed) {
-      // When closing the web-socket, we no longer accept data.
-      _closeTimer = new Timer(const Duration(seconds: 5), () {
-        _subscription.cancel();
-        _controller.close();
-      });
-    }
-    return _sink.close();
-  }
-
-  void _close([int code, String reason]) {
-    if (_writeClosed) return;
-    if (_outCloseCode == null) {
-      _outCloseCode = code;
-      _outCloseReason = reason;
-    }
-    _writeClosed = true;
-    _consumer.closeSocket();
-  }
-
-  static bool _isReservedStatusCode(int code) {
-    return code != null &&
-           (code < _WebSocketStatus.NORMAL_CLOSURE ||
-            code == _WebSocketStatus.RESERVED_1004 ||
-            code == _WebSocketStatus.NO_STATUS_RECEIVED ||
-            code == _WebSocketStatus.ABNORMAL_CLOSURE ||
-            (code > _WebSocketStatus.INTERNAL_SERVER_ERROR &&
-             code < _WebSocketStatus.RESERVED_1015) ||
-            (code >= _WebSocketStatus.RESERVED_1015 &&
-             code < 3000));
-  }
-}
-