Index: mojo/public/dart/third_party/barback/lib/src/serialize.dart |
diff --git a/mojo/public/dart/third_party/barback/lib/src/serialize.dart b/mojo/public/dart/third_party/barback/lib/src/serialize.dart |
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index 0000000000000000000000000000000000000000..10cc6fe06e30c431f0f310cf7ed6b01ae3115e06 |
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+// 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. |
+ |
+library barback.serialize; |
+ |
+import 'dart:async'; |
+import 'dart:isolate'; |
+ |
+import 'package:stack_trace/stack_trace.dart'; |
+ |
+import 'asset/asset_id.dart'; |
+import 'utils.dart'; |
+ |
+/// Converts [id] into a serializable map. |
+Map serializeId(AssetId id) => {'package': id.package, 'path': id.path}; |
+ |
+/// Converts [stream] into a [SendPort] with which another isolate can request |
+/// the data from [stream]. |
+SendPort serializeStream(Stream stream) { |
+ var receivePort = new ReceivePort(); |
+ receivePort.first.then((sendPort) { |
+ stream.listen((data) => sendPort.send({'type': 'data', 'data': data}), |
+ onDone: () => sendPort.send({'type': 'done'}), |
+ onError: (error, stackTrace) { |
+ sendPort.send({ |
+ 'type': 'error', |
+ 'error': CrossIsolateException.serialize(error, stackTrace) |
+ }); |
+ }); |
+ }); |
+ |
+ return receivePort.sendPort; |
+} |
+ |
+/// Converts a serializable map into an [AssetId]. |
+AssetId deserializeId(Map id) => new AssetId(id['package'], id['path']); |
+ |
+/// Convert a [SendPort] whose opposite is waiting to send us a stream into a |
+/// [Stream]. |
+/// |
+/// No stream data will actually be sent across the isolate boundary until |
+/// someone subscribes to the returned stream. |
+Stream deserializeStream(SendPort sendPort) { |
+ return callbackStream(() { |
+ var receivePort = new ReceivePort(); |
+ sendPort.send(receivePort.sendPort); |
+ return receivePort.transform( |
+ const StreamTransformer(_deserializeTransformer)); |
+ }); |
+} |
+ |
+/// The body of a [StreamTransformer] that deserializes the values in a stream |
+/// sent by [serializeStream]. |
+StreamSubscription _deserializeTransformer(Stream input, bool cancelOnError) { |
+ var subscription; |
+ var transformed = input.transform(new StreamTransformer.fromHandlers( |
+ handleData: (data, sink) { |
+ if (data['type'] == 'data') { |
+ sink.add(data['data']); |
+ } else if (data['type'] == 'error') { |
+ var exception = new CrossIsolateException.deserialize(data['error']); |
+ sink.addError(exception, exception.stackTrace); |
+ } else { |
+ assert(data['type'] == 'done'); |
+ sink.close(); |
+ subscription.cancel(); |
+ } |
+ })); |
+ subscription = transformed.listen(null, cancelOnError: cancelOnError); |
+ return subscription; |
+} |
+ |
+/// An exception that was originally raised in another isolate. |
+/// |
+/// Exception objects can't cross isolate boundaries in general, so this class |
+/// wraps as much information as can be consistently serialized. |
+class CrossIsolateException implements Exception { |
+ /// The name of the type of exception thrown. |
+ /// |
+ /// This is the return value of [error.runtimeType.toString()]. Keep in mind |
+ /// that objects in different libraries may have the same type name. |
+ final String type; |
+ |
+ /// The exception's message, or its [toString] if it didn't expose a `message` |
+ /// property. |
+ final String message; |
+ |
+ /// The exception's stack chain, or `null` if no stack chain was available. |
+ final Chain stackTrace; |
+ |
+ /// Loads a [CrossIsolateException] from a serialized representation. |
+ /// |
+ /// [error] should be the result of [CrossIsolateException.serialize]. |
+ CrossIsolateException.deserialize(Map error) |
+ : type = error['type'], |
+ message = error['message'], |
+ stackTrace = error['stack'] == null ? null : |
+ new Chain.parse(error['stack']); |
+ |
+ /// Serializes [error] to an object that can safely be passed across isolate |
+ /// boundaries. |
+ static Map serialize(error, [StackTrace stack]) { |
+ if (stack == null && error is Error) stack = error.stackTrace; |
+ return { |
+ 'type': error.runtimeType.toString(), |
+ 'message': getErrorMessage(error), |
+ 'stack': stack == null ? null : new Chain.forTrace(stack).toString() |
+ }; |
+ } |
+ |
+ String toString() => "$message\n$stackTrace"; |
+} |