Move //mojo/{public, edk} underneath //third_party

mojo/public/dart/src/event_stream.dart

-// Copyright 2014 The Chromium Authors. 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 core;
-
-class MojoEventStream extends Stream<int> {
-  // The underlying Mojo handle.
-  MojoHandle _handle;
-
-  // Providing our own stream controller allows us to take custom actions when
-  // listeners pause/resume/etc. their StreamSubscription.
-  StreamController _controller;
-
-  // The send port that we give to the handle watcher to notify us of handle
-  // events.
-  SendPort _sendPort;
-
-  // The receive port on which we listen and receive events from the handle 
-  // watcher.
-  ReceivePort _receivePort;
-
-  // The signals on this handle that we're interested in.
-  MojoHandleSignals _signals;
-
-  // Whether listen has been called.
-  bool _isListening;
-
-  MojoEventStream(MojoHandle handle,
-                  [MojoHandleSignals signals = MojoHandleSignals.READABLE]) :
-      _handle = handle,
-      _signals = signals,
-      _isListening = false {
-    MojoResult result = MojoHandle.register(this);
-    if (!result.isOk) {
-      throw "Failed to register the MojoHandle: $result.";
-    }
-  }
-
-  void close() {
-    if (_handle != null) {
-      MojoHandleWatcher.close(_handle);
-      _handle = null;
-    }
-    if (_receivePort != null) {
-      _receivePort.close();
-      _receivePort = null;
-    }
-  }
-
-  StreamSubscription<List<int>> listen(
-      void onData(List event),
-      {Function onError, void onDone(), bool cancelOnError}) {
-    if (_isListening) {
-      throw "Listen has already been called: $_handle.";
-    }
-    _receivePort = new ReceivePort();
-    _sendPort = _receivePort.sendPort;
-    _controller = new StreamController(sync: true,
-        onListen: _onSubscriptionStateChange,
-        onCancel: _onSubscriptionStateChange,
-        onPause: _onPauseStateChange,
-        onResume: _onPauseStateChange);
-    _controller.addStream(_receivePort);
-
-    if (_signals != MojoHandleSignals.NONE) {
-      var res = MojoHandleWatcher.add(_handle, _sendPort, _signals.value);
-      if (!res.isOk) {
-        throw "MojoHandleWatcher add failed: $res";
-      }
-    }
-
-    _isListening = true;
-    return _controller.stream.listen(
-        onData,
-        onError: onError,
-        onDone: onDone,
-        cancelOnError: cancelOnError);
-  }
-
-  void enableSignals(MojoHandleSignals signals) {
-    _signals = signals;
-    if (_isListening) {
-      var res = MojoHandleWatcher.add(_handle, _sendPort, signals.value);
-      if (!res.isOk) {
-        throw "MojoHandleWatcher add failed: $res";
-      }
-    }
-  }
-
-  void enableReadEvents() => enableSignals(MojoHandleSignals.READABLE);
-  void enableWriteEvents() => enableSignals(MojoHandleSignals.WRITABLE);
-  void enableAllEvents() => enableSignals(MojoHandleSignals.READWRITE);
-
-  void _onSubscriptionStateChange() {
-    if (!_controller.hasListener) {
-      close();
-    }
-  }
-
-  void _onPauseStateChange() {
-    if (_controller.isPaused) {
-      var res = MojoHandleWatcher.remove(_handle);
-      if (!res.isOk) {
-        throw "MojoHandleWatcher add failed: $res";
-      }
-    } else {
-      var res = MojoHandleWatcher.add(_handle, _sendPort, _signals.value);
-      if (!res.isOk) {
-        throw "MojoHandleWatcher add failed: $res";
-      }
-    }
-  }
-
-  bool get readyRead => _handle.readyRead;
-  bool get readyWrite => _handle.readyWrite;
-
-  String toString() => "$_handle";
-}
-
-
-class MojoEventStreamListener {
-  MojoMessagePipeEndpoint _endpoint;
-  MojoEventStream _eventStream;
-  bool _isOpen = false;
-  bool _isInHandler = false;
-
-  MojoEventStreamListener(MojoMessagePipeEndpoint endpoint) :
-      _endpoint = endpoint,
-      _eventStream = new MojoEventStream(endpoint.handle),
-      _isOpen = false;
-
-  MojoEventStreamListener.fromHandle(MojoHandle handle) {
-    _endpoint = new MojoMessagePipeEndpoint(handle);
-    _eventStream = new MojoEventStream(handle);
-    _isOpen = false;
-  }
-
-  MojoEventStreamListener.unbound() :
-      _endpoint = null,
-      _eventStream = null,
-      _isOpen = false;
-
-  void bind(MojoMessagePipeEndpoint endpoint) {
-    assert(!isBound);
-    _endpoint = endpoint;
-    _eventStream = new MojoEventStream(endpoint.handle);
-    _isOpen = false;
-  }
-
-  void bindFromHandle(MojoHandle handle) {
-    assert(!isBound);
-    _endpoint = new MojoMessagePipeEndpoint(handle);
-    _eventStream = new MojoEventStream(handle);
-    _isOpen = false;
-  }
-
-  StreamSubscription<int> listen() {
-    _isOpen = true;
-    return _eventStream.listen((List<int> event) {
-      var signalsWatched = new MojoHandleSignals(event[0]);
-      var signalsReceived = new MojoHandleSignals(event[1]);
-      if (signalsReceived.isPeerClosed) {
-        handlePeerClosed();
-        // The peer being closed obviates any other signal we might
-        // have received since we won't be able to read or write the handle.
-        // Thus, we just return before invoking other handlers.
-        return;
-      }
-      _isInHandler = true;
-      if (signalsReceived.isReadable) {
-        assert(_eventStream.readyRead);
-        handleRead();
-      }
-      if (signalsReceived.isWritable) {
-        assert(_eventStream.readyWrite);
-        handleWrite();
-      }
-      _eventStream.enableSignals(enableSignals(
-          signalsWatched, signalsReceived));
-      _isInHandler = false;
-    });
-  }
-
-  void close() {
-    if (_isOpen) {
-      _eventStream.close();
-      _isOpen = false;
-      _eventStream = null;
-      _endpoint = null;
-    }
-  }
-
-  void handleRead() {}
-  void handleWrite() {}
-  void handlePeerClosed() {
-    close();
-  }
-
-  MojoHandleSignals enableSignals(MojoHandleSignals watched,
-                                  MojoHandleSignals received) => watched;
-
-  MojoMessagePipeEndpoint get endpoint => _endpoint;
-  bool get isOpen => _isOpen;
-  bool get isInHandler => _isInHandler;
-  bool get isBound => _endpoint != null;
-}