Rationalize Dart mojo and sky package structure

mojo/public/dart/src/handle_watcher.dart

Index: mojo/public/dart/src/handle_watcher.dart
diff --git a/mojo/public/dart/src/handle_watcher.dart b/mojo/public/dart/src/handle_watcher.dart
deleted file mode 100644
index 4aeeaffd0bed4bb770a458fe63b0738240c5ae85..0000000000000000000000000000000000000000
--- a/mojo/public/dart/src/handle_watcher.dart
+++ /dev/null
@@ -1,353 +0,0 @@
-// 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 internal;
-
-// The MojoHandleWatcher sends a stream of events to application isolates that
-// register Mojo handles with it. Application isolates make the following calls:
-//
-// add(handle, port, signals) - Instructs the MojoHandleWatcher isolate to add
-//     'handle' to the set of handles it watches, and to notify the calling
-//     isolate only for the events specified by 'signals' using the send port
-//     'port'
-//
-// remove(handle) - Instructs the MojoHandleWatcher isolate to remove 'handle'
-//     from the set of handles it watches. This allows the application isolate
-//     to, e.g., pause the stream of events.
-//
-// close(handle) - Notifies the HandleWatcherIsolate that a handle it is
-//     watching should be removed from its set and closed.
-class MojoHandleWatcher {
-  // Control commands.
-  static const int ADD = 0;
-  static const int REMOVE = 1;
-  static const int CLOSE = 2;
-  static const int TIMER = 3;
-  static const int SHUTDOWN = 4;
-
-  static const int kMojoHandleInvalid = 0;
-  static const int kDeadlineIndefinite = -1;
-
-  static const int kMojoResultOk = 0;
-  static const int kMojoResultDeadlineExceeded = 4;
-  static const int kMojoResultFailedPrecondition = 9;
-
-  static const int kMojoSignalsReadable = (1 << 0);
-  static const int kMojoSignalsWritable = (1 << 1);
-  static const int kMojoSignalsPeerClosed = (1 << 2);
-  static const int kMojoSignalsAll =
-      kMojoSignalsReadable | kMojoSignalsWritable | kMojoSignalsPeerClosed;
-
-  static int _encodeCommand(int cmd, [int signals = 0]) =>
-      (cmd << 3) | (signals & kMojoSignalsAll);
-  static int _decodeCommand(int cmd) {
-    assert(kMojoSignalsAll < 1 << 3);
-    return cmd >> 3;
-  }
-  static int _decodeSignals(int cmd) {
-    return cmd & kMojoSignalsAll;
-  }
-
-  // The Mojo handle over which control messages are sent.
-  int _controlHandle;
-
-  // Whether the handle watcher should shut down.
-  bool _shutdown;
-
-  // The list of handles being watched.
-  List<int> _handles;
-  int _handleCount;
-
-  // A port for each handle on which to send events back to the isolate that
-  // owns the handle.
-  List<SendPort> _ports;
-
-  // The signals that we care about for each handle.
-  List<int> _signals;
-
-  // A mapping from Mojo handles to their indices in _handles.
-  Map<int, int> _handleIndices;
-
-  // Priority queue of timers registered with the watcher.
-  TimerQueue _timerQueue;
-
-  MojoHandleWatcher(this._controlHandle)
-      : _shutdown = false,
-        _handles = new List<int>(),
-        _ports = new List<SendPort>(),
-        _signals = new List<int>(),
-        _handleIndices = new Map<int, int>(),
-        _handleCount = 1,
-        _timerQueue = new TimerQueue() {
-    // Setup control handle.
-    _handles.add(_controlHandle);
-    _ports.add(null); // There is no port for the control handle.
-    _signals.add(kMojoSignalsReadable);
-    _handleIndices[_controlHandle] = 0;
-  }
-
-  static void _handleWatcherIsolate(int consumerHandle) {
-    MojoHandleWatcher watcher = new MojoHandleWatcher(consumerHandle);
-    while (!watcher._shutdown) {
-      int deadline = watcher._processTimerDeadlines();
-      // mwmr[0]: result, mwmr[1]: index, mwmr[2]: list of signal states.
-      List mwmr = MojoHandleNatives.waitMany(
-          watcher._handles, watcher._signals, deadline);
-      if ((mwmr[0] == kMojoResultOk) && (mwmr[1] == 0)) {
-        watcher._handleControlMessage();
-      } else if ((mwmr[0] == kMojoResultOk) && (mwmr[1] > 0)) {
-        int handle = watcher._handles[mwmr[1]];
-
-        // Route event.
-        watcher._routeEvent(mwmr[2][mwmr[1]][0], mwmr[1]);
-        // Remove the handle from the list.
-        watcher._removeHandle(handle);
-      } else if (mwmr[0] != kMojoResultDeadlineExceeded) {
-        // Some handle was closed, but not by us.
-        // Find it and close it on our side.
-        watcher._pruneClosedHandles(mwmr[2]);
-      }
-    }
-  }
-
-  void _routeEvent(int satisfiedSignals, int idx) {
-    _ports[idx].send([_signals[idx], satisfiedSignals & _signals[idx]]);
-  }
-
-  void _handleControlMessage() {
-    List result = MojoHandleWatcherNatives.recvControlData(_controlHandle);
-    // result[0] = mojo handle if any, or a timer deadline in milliseconds.
-    // result[1] = SendPort if any.
-    // result[2] = command << 2 | WRITABLE | READABLE
-
-    var signals = _decodeSignals(result[2]);
-    int command = _decodeCommand(result[2]);
-    switch (command) {
-      case ADD:
-        _addHandle(result[0], result[1], signals);
-        break;
-      case REMOVE:
-        _removeHandle(result[0]);
-        break;
-      case CLOSE:
-        _close(result[0], result[1]);
-        break;
-      case TIMER:
-        _timer(result[1], result[0]);
-        break;
-      case SHUTDOWN:
-        _shutdownHandleWatcher(result[1]);
-        break;
-      default:
-        throw "Invalid Command: $command";
-        break;
-    }
-  }
-
-  void _addHandle(int mojoHandle, SendPort port, int signals) {
-    int idx = _handleIndices[mojoHandle];
-    if (idx == null) {
-      _handles.add(mojoHandle);
-      _ports.add(port);
-      _signals.add(signals);
-      _handleIndices[mojoHandle] = _handleCount;
-      _handleCount++;
-    } else {
-      assert(_ports[idx] == port);
-      assert(_handles[idx] == mojoHandle);
-      _signals[idx] |= signals;
-    }
-  }
-
-  void _removeHandle(int mojoHandle) {
-    int idx = _handleIndices[mojoHandle];
-    if (idx == null) {
-      throw "Remove on a non-existent handle: idx = $idx.";
-    }
-    if (idx == 0) {
-      throw "The control handle (idx = 0) cannot be removed.";
-    }
-    // We don't use List.removeAt so that we know how to fix-up _handleIndices.
-    if (idx == _handleCount - 1) {
-      int handle = _handles[idx];
-      _handleIndices[handle] = null;
-      _handles.removeLast();
-      _signals.removeLast();
-      _ports.removeLast();
-      _handleCount--;
-    } else {
-      int last = _handleCount - 1;
-      _handleIndices[_handles[idx]] = null;
-      _handles[idx] = _handles[last];
-      _signals[idx] = _signals[last];
-      _ports[idx] = _ports[last];
-      _handles.removeLast();
-      _signals.removeLast();
-      _ports.removeLast();
-      _handleIndices[_handles[idx]] = idx;
-      _handleCount--;
-    }
-  }
-
-  void _close(int mojoHandle, SendPort port, {bool pruning: false}) {
-    assert(!pruning || (port == null));
-    int idx = _handleIndices[mojoHandle];
-    if (idx == null) {
-      // An app isolate may request that the handle watcher close a handle that
-      // has already been pruned. This happens when the app isolate has not yet
-      // received the PEER_CLOSED event. The app isolate will not close the
-      // handle, so we must do so here.
-      MojoHandleNatives.close(mojoHandle);
-      if (port != null) port.send(null); // Notify that close is done.
-      return;
-    }
-    if (idx == 0) {
-      throw "The control handle (idx = 0) cannot be closed.";
-    }
-    MojoHandleNatives.close(_handles[idx]);
-    if (port != null) port.send(null); // Notify that close is done.
-    if (pruning) {
-      // If this handle is being pruned, notify the application isolate
-      // by sending MojoHandleSignals.PEER_CLOSED.
-      _ports[idx].send([_signals[idx], kMojoSignalsPeerClosed]);
-    }
-    _removeHandle(mojoHandle);
-  }
-
-  // Returns the next timer deadline in units of microseconds from 'now'.
-  int _processTimerDeadlines() {
-    int now = (new DateTime.now()).millisecondsSinceEpoch;
-    while (_timerQueue.hasTimer && (now >= _timerQueue.currentTimeout)) {
-      _timerQueue.currentPort.send(null);
-      _timerQueue.removeCurrent();
-      now = (new DateTime.now()).millisecondsSinceEpoch;
-    }
-    return _timerQueue.hasTimer
-        ? (_timerQueue.currentTimeout - now) * 1000
-        : kDeadlineIndefinite;
-  }
-
-  void _timer(SendPort port, int deadline) {
-    _timerQueue.updateTimer(port, deadline);
-  }
-
-  void _pruneClosedHandles(List<List<int>> states) {
-    List<int> closed = new List();
-    for (var i = 0; i < _handles.length; i++) {
-      if (states != null) {
-        int signals = states[i][0];
-        if ((signals & kMojoSignalsPeerClosed) != 0) {
-          closed.add(_handles[i]);
-        }
-      } else {
-        List mwr = MojoHandleNatives.wait(_handles[i], kMojoSignalsAll, 0);
-        if ((mwr[0] != kMojoResultOk) &&
-            (mwr[0] != kMojoResultDeadlineExceeded)) {
-          closed.add(_handles[i]);
-        }
-      }
-    }
-    for (var h in closed) {
-      _close(h, null, pruning: true);
-    }
-    // '_close' updated the '_handles' array, so at this point the '_handles'
-    // array and the caller's 'states' array are mismatched.
-  }
-
-  void _shutdownHandleWatcher(SendPort shutdownSendPort) {
-    _shutdown = true;
-    MojoHandleNatives.close(_controlHandle);
-    shutdownSendPort.send(null);
-  }
-
-  static int _sendControlData(int rawHandle, SendPort port, int data) {
-    int controlHandle = MojoHandleWatcherNatives.getControlHandle();
-    if (controlHandle == kMojoHandleInvalid) {
-      return kMojoResultFailedPrecondition;
-    }
-
-    var result = MojoHandleWatcherNatives.sendControlData(
-        controlHandle, rawHandle, port, data);
-    return result;
-  }
-
-  // Starts up the MojoHandleWatcher isolate. Should be called only once
-  // per VM process.
-  static Future<Isolate> _start() {
-    // Make a control message pipe,
-    List pipeEndpoints = MojoMessagePipeNatives.MojoCreateMessagePipe(0);
-    assert(pipeEndpoints != null);
-    assert((pipeEndpoints is List) && (pipeEndpoints.length == 3));
-    assert(pipeEndpoints[0] == kMojoResultOk);
-
-    int consumerHandle = pipeEndpoints[1];
-    int producerHandle = pipeEndpoints[2];
-
-    // Call setControlHandle with the other end.
-    assert(producerHandle != kMojoHandleInvalid);
-    MojoHandleWatcherNatives.setControlHandle(producerHandle);
-
-    // Spawn the handle watcher isolate with the MojoHandleWatcher,
-    return Isolate.spawn(_handleWatcherIsolate, consumerHandle);
-  }
-
-  // Causes the MojoHandleWatcher isolate to exit. Should be called only
-  // once per VM process.
-  static void _stop() {
-    // Create a port for notification that the handle watcher has shutdown.
-    var shutdownReceivePort = new ReceivePort();
-    var shutdownSendPort = shutdownReceivePort.sendPort;
-
-    // Send the shutdown command.
-    _sendControlData(
-        kMojoHandleInvalid, shutdownSendPort, _encodeCommand(SHUTDOWN));
-
-    // Close the control handle.
-    int controlHandle = MojoHandleWatcherNatives.getControlHandle();
-    MojoHandleNatives.close(controlHandle);
-
-    // Invalidate the control handle.
-    MojoHandleWatcherNatives.setControlHandle(kMojoHandleInvalid);
-
-    // Wait for the handle watcher isolate to exit.
-    shutdownReceivePort.first.then((_) {
-      shutdownReceivePort.close();
-    });
-  }
-
-  // If wait is true, returns a future that resolves only after the handle
-  // has actually been closed by the handle watcher. Otherwise, returns a
-  // future that resolves immediately.
-  static Future<int> close(int mojoHandle, {bool wait: false}) {
-    //assert(MojoHandle._removeUnclosedHandle(mojoHandle));
-    if (!wait) {
-      return new Future.value(
-          _sendControlData(mojoHandle, null, _encodeCommand(CLOSE)));
-    }
-    int result;
-    var completer = new Completer();
-    var rawPort = new RawReceivePort((_) {
-      completer.complete(result);
-    });
-    result =
-        _sendControlData(mojoHandle, rawPort.sendPort, _encodeCommand(CLOSE));
-    return completer.future.then((r) {
-      rawPort.close();
-      return r;
-    });
-  }
-
-  static int add(int mojoHandle, SendPort port, int signals) {
-    return _sendControlData(mojoHandle, port, _encodeCommand(ADD, signals));
-  }
-
-  static int remove(int mojoHandle) {
-    return _sendControlData(mojoHandle, null, _encodeCommand(REMOVE));
-  }
-
-  static int timer(Object ignored, SendPort port, int deadline) {
-    // The deadline will be unwrapped before sending to the handle watcher.
-    return _sendControlData(deadline, port, _encodeCommand(TIMER));
-  }
-}