Removed fixed dependencies

packages/isolate/lib/ports.dart

+// Copyright (c) 2015, 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.
+
+/// Utility functions for setting up ports and sending data.
+///
+/// This library contains a number of functions that handle the
+/// boiler-plate of setting up a receive port and receiving a
+/// single message on the port.
+///
+/// There are different functions that offer different ways to
+/// handle the incoming message.
+///
+/// The simplest function, [singleCallbackPort], takes a callback
+/// and returns a port, and then calls the callback for the first
+/// message sent on the port.
+///
+/// Other functions intercept the returned value and either
+/// does something with it, or puts it into a [Future] or [Completer].
+library isolate.ports;
+
+import "dart:async";
+import "dart:isolate";
+
+import "src/lists.dart";
+
+/// Create a [SendPort] that accepts only one message.
+///
+/// The [callback] function is called once, with the first message
+/// received by the receive port.
+/// All further messages are ignored.
+///
+/// If [timeout] is supplied, it is used as a limit on how
+/// long it can take before the message is received. If a
+/// message isn't received in time, the `callback` function
+/// is called once with the [timeoutValue] instead.
+///
+/// Returns the `SendPort` expecting the single message.
+///
+/// Equivalent to:
+///
+///     (new ReceivePort()
+///         ..first.timeout(duration, () => timeoutValue).then(callback))
+///         .sendPort
+SendPort singleCallbackPort(void callback(response),
+                            {Duration timeout,
+                             var timeoutValue}) {
+  RawReceivePort responsePort = new RawReceivePort();
+  Zone zone = Zone.current;
+  callback = zone.registerUnaryCallback(callback);
+  var timer;
+  responsePort.handler = (response) {
+    responsePort.close();
+    if (timer != null) timer.cancel();
+    zone.runUnary(callback, response);
+  };
+  if (timeout != null) {
+    timer = new Timer(timeout, () {
+      responsePort.close();
+      callback(timeoutValue);
+    });
+  }
+  return responsePort.sendPort;
+}
+
+/// Create a [SendPort] that accepts only one message.
+///
+/// When the first message is received, the [callback] function is
+/// called with the message as argument,
+/// and the [completer] is completed with the result of that call.
+/// All further messages are ignored.
+///
+/// If `callback` is omitted, it defaults to an identity function.
+/// The `callback` call may return a future, and the completer will
+/// wait for that future to complete.
+///
+/// If [timeout] is supplied, it is used as a limit on how
+/// long it can take before the message is received. If a
+/// message isn't received in time, the [onTimeout] is called,
+/// and `completer` is completed with the result of that call
+/// instead.
+/// The [callback] function will not be interrupted by the time-out,
+/// as long as the initial message is received in time.
+/// If `onTimeout` is omitted, it defaults to completing the `completer` with
+/// a [TimeoutException].
+///
+/// The [completer] may be a synchronous completer. It is only
+/// completed in response to another event, either a port message or a timer.
+///
+/// Returns the `SendPort` expecting the single message.
+SendPort singleCompletePort(Completer completer,
+                            {callback(message),
+                             Duration timeout,
+                             onTimeout()}) {
+  if (callback == null && timeout == null) {
+    return singleCallbackPort(completer.complete);
+  }
+  RawReceivePort responsePort = new RawReceivePort();
+  var timer;
+  if (callback == null) {
+    responsePort.handler = (response) {
+      responsePort.close();
+      if (timer != null) timer.cancel();
+      completer.complete(response);
+    };
+  } else {
+    Zone zone = Zone.current;
+    Function action = zone.registerUnaryCallback((response) {
+      completer.complete(new Future.sync(() => callback(response)));
+    });
+    responsePort.handler = (response) {
+      responsePort.close();
+      if (timer != null) timer.cancel();
+      zone.runUnary(action, response);
+    };
+  }
+  if (timeout != null) {
+    timer = new Timer(timeout, () {
+      responsePort.close();
+      if (onTimeout != null) {
+        completer.complete(new Future.sync(onTimeout));
+      } else {
+        completer.completeError(
+              new TimeoutException("Future not completed", timeout));
+      }
+    });
+  }
+  return responsePort.sendPort;
+}
+
+/// Creates a [Future], and a [SendPort] that can be used to complete that
+/// future.
+///
+/// Calls [action] with the response `SendPort`, then waits for someone
+/// to send a value on that port
+/// The returned `Future` is completed with the value sent on the port.
+///
+/// If [action] throws, which it shouldn't,
+/// the returned future is completed with that error.
+/// Any return value of `action` is ignored, and if it is asynchronous,
+/// it should handle its own errors.
+///
+/// If [timeout] is supplied, it is used as a limit on how
+/// long it can take before the message is received. If a
+/// message isn't received in time, the [timeoutValue] used
+/// as the returned future's value instead.
+///
+/// If you want a timeout on the returned future, it's recommended to
+/// use the [timeout] parameter, and not [Future.timeout] on the result.
+/// The `Future` method won't be able to close the underlying [ReceivePort].
+Future singleResponseFuture(void action(SendPort responsePort),
+                            {Duration timeout,
+                             var timeoutValue}) {
+  Completer completer = new Completer.sync();
+  RawReceivePort responsePort = new RawReceivePort();
+  Timer timer;
+  Zone zone = Zone.current;
+  responsePort.handler = (v) {
+    responsePort.close();
+    if (timer != null) timer.cancel();
+    zone.run(() {
+      completer.complete(v);
+    });
+  };
+  if (timeout != null) {
+    timer = new Timer(timeout, () {
+      responsePort.close();
+      completer.complete(timeoutValue);
+    });
+  }
+  try {
+    action(responsePort.sendPort);
+  } catch (e, s) {
+    responsePort.close();
+    if (timer != null) timer.cancel();
+    // Delay completion because completer is sync.
+    scheduleMicrotask(() {
+      completer.completeError(e, s);
+    });
+  }
+  return completer.future;
+}
+
+
+/// Send the result of a future, either value or error, as a message.
+///
+/// The result of [future] is sent on [resultPort] in a form expected by
+/// either [receiveFutureResult], [completeFutureResult], or
+/// by the port of [singleResultFuture].
+void sendFutureResult(Future future, SendPort resultPort) {
+  future.then(
+    (v) { resultPort.send(list1(v));
+  }, onError: (e, s) {
+    resultPort.send(list2("$e", "$s"));
+  });
+}
+
+
+/// Creates a [Future], and a [SendPort] that can be used to complete that
+/// future.
+///
+/// Calls [action] with the response `SendPort`, then waits for someone
+/// to send a future result on that port using [sendFutureResult].
+/// The returned `Future` is completed with the future result sent on the port.
+///
+/// If [action] throws, which it shouldn't,
+/// the returned future is completed with that error,
+/// unless someone manages to send a message on the port before `action` throws.
+///
+/// If [timeout] is supplied, it is used as a limit on how
+/// long it can take before the message is received. If a
+/// message isn't received in time, the [onTimeout] is called,
+/// and the future is completed with the result of that call
+/// instead.
+/// If `onTimeout` is omitted, it defaults to throwing
+/// a [TimeoutException].
+Future singleResultFuture(void action(SendPort responsePort),
+                          {Duration timeout,
+                           onTimeout()}) {
+  Completer completer = new Completer.sync();
+  SendPort port = singleCompletePort(completer,
+                                     callback: receiveFutureResult,
+                                     timeout: timeout,
+                                     onTimeout: onTimeout);
+  try {
+    action(port);
+  } catch (e, s) {
+    // This should not happen.
+    sendFutureResult(new Future.error(e, s), port);
+  }
+  return completer.future;
+}
+
+/// Completes a completer with a message created by [sendFutureResult]
+///
+/// The [response] must be a message on the format sent by [sendFutureResult].
+void completeFutureResult(var response, Completer completer) {
+  if (response.length == 2) {
+    var error = new RemoteError(response[0], response[1]);
+    completer.completeError(error, error.stackTrace);
+  } else {
+    var result = response[0];
+    completer.complete(result);
+  }
+}
+
+
+/// Converts a received message created by [sendFutureResult] to a future
+/// result.
+///
+/// The [response] must be a message on the format sent by [sendFutureResult].
+Future receiveFutureResult(var response) {
+  if (response.length == 2) {
+    var error = new RemoteError(response[0], response[1]);
+    return new Future.error(error, error.stackTrace);
+  }
+  var result = response[0];
+  return new Future.value(result);
+}
+
+/// A [Future] and a [SendPort] that can be used to complete the future.
+///
+/// The first value sent to [port] is used to complete the [result].
+/// All following values sent to `port` are ignored.
+class SingleResponseChannel {
+  Zone _zone;
+  final RawReceivePort _receivePort;
+  final Completer _completer;
+  final Function _callback;
+  Timer _timer;
+
+  /// Creates a response channel.
+  ///
+  /// The [result] is completed with the first value sent to [port].
+  ///
+  /// If [callback] is provided, the value sent to [port] is first passed
+  /// to `callback`, and the result of that is used to complete `result`.
+  ///
+  /// If [timeout] is provided, the future is completed after that
+  /// duration if it hasn't received a value from the port earlier.
+  /// If [throwOnTimeout] is true, the the future is completed with a
+  /// [TimeoutException] as an error if it times out.
+  /// Otherwise, if [onTimeout] is provided,
+  /// the future is completed with the result of running `onTimeout()`.
+  /// If `onTimeout` is not provided either,
+  /// the future is completed with `timeoutValue`, which defaults to `null`.
+  SingleResponseChannel({callback(value),
+                         Duration timeout,
+                         bool throwOnTimeout: false,
+                         onTimeout(),
+                         var timeoutValue})
+      : _receivePort = new RawReceivePort(),
+        _completer = new Completer.sync(),
+        _callback = callback,
+        _zone = Zone.current {
+    _receivePort.handler = _handleResponse;
+    if (timeout != null) {
+      _timer = new Timer(timeout, () {
+        // Executed as a timer event.
+        _receivePort.close();
+        if (!_completer.isCompleted) {
+          if (throwOnTimeout) {
+            _completer.completeError(
+                new TimeoutException('Timeout waiting for response', timeout));
+          } else if (onTimeout != null) {
+            _completer.complete(new Future.sync(onTimeout));
+          } else {
+            _completer.complete(timeoutValue);
+          }
+        }
+      });
+    }
+  }
+
+  /// The port expecting a value that will complete [result].
+  SendPort get port => _receivePort.sendPort;
+
+  /// Future completed by the first value sent to [port].
+  Future get result => _completer.future;
+
+  /// If the channel hasn't completed yet, interrupt it and complete the result.
+  ///
+  /// If the channel hasn't received a value yet, or timed out, it is stopped
+  /// (like by a timeout) and the [SingleResponseChannel.result]
+  /// is completed with [result].
+  void interrupt([result]) {
+    _receivePort.close();
+    _cancelTimer();
+    if (!_completer.isCompleted) {
+      // Not in event tail position, so complete the sync completer later.
+      _completer.complete(new Future.microtask(() => result));
+    }
+  }
+
+  void _cancelTimer() {
+    if (_timer != null) {
+      _timer.cancel();
+      _timer = null;
+    }
+  }
+
+  void _handleResponse(v) {
+    // Executed as a port event.
+    _receivePort.close();
+    _cancelTimer();
+    if (_callback == null) {
+      _completer.complete(v);
+    } else {
+      // The _handleResponse function is the handler of a RawReceivePort.
+      // As such, it runs in the root zone.
+      // The _callback should be run in the original zone, both because it's
+      // what the user expects, and because it may create an error that needs
+      // to be propagated to the original completer. If that completer was
+      // created in a different error zone, an error from the root zone
+      // would become uncaught.
+      _zone.run(() {
+        _completer.complete(new Future.sync(() => _callback(v)));
+      });
+    }
+  }
+}