Dart: Better handle leak checks. close() is async.

mojo/public/dart/src/message.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 bindings;
 
 class MessageHeader {
   static const int kSimpleMessageSize = 16;
   // TODO(yzshen): In order to work with other bindings which still interprets
   // the |version| field as |num_fields|, set it to version 2 for now.
   static const int kSimpleMessageVersion = 2;
   static const int kMessageWithRequestIdSize = 24;
   // TODO(yzshen): In order to work with other bindings which still interprets
   // the |version| field as |num_fields|, set it to version 3 for now.
   static const int kMessageWithRequestIdVersion = 3;
   static const int kMessageTypeOffset = StructDataHeader.kHeaderSize;
   static const int kMessageFlagsOffset = kMessageTypeOffset + 4;
   static const int kMessageRequestIdOffset = kMessageFlagsOffset + 4;
   static const int kMessageExpectsResponse = 1 << 0;
   static const int kMessageIsResponse = 1 << 1;
 
   StructDataHeader _header;
   int type;
   int flags;
   int requestId;
 
   static bool mustHaveRequestId(int flags) =>
       (flags & (kMessageExpectsResponse | kMessageIsResponse)) != 0;
 
-  MessageHeader(this.type) :
-    _header = new StructDataHeader(kSimpleMessageSize, kSimpleMessageVersion),
-    flags = 0,
-    requestId = 0;
+  MessageHeader(this.type)
+      : _header = new StructDataHeader(
+          kSimpleMessageSize, kSimpleMessageVersion),
+        flags = 0,
+        requestId = 0;
 
-  MessageHeader.withRequestId(this.type, this.flags, this.requestId) :
-    _header = new StructDataHeader(
-        kMessageWithRequestIdSize, kMessageWithRequestIdVersion);
+  MessageHeader.withRequestId(this.type, this.flags, this.requestId)
+      : _header = new StructDataHeader(
+          kMessageWithRequestIdSize, kMessageWithRequestIdVersion);
 
   MessageHeader.fromMessage(Message message) {
     var decoder = new Decoder(message);
     _header = decoder.decodeStructDataHeader();
     if (_header.size < kSimpleMessageSize) {
-      throw new MojoCodecError(
-          'Incorrect message size. Got: ${_header.size} '
+      throw new MojoCodecError('Incorrect message size. Got: ${_header.size} '
           'wanted $kSimpleMessageSize');
     }
     type = decoder.decodeUint32(kMessageTypeOffset);
     flags = decoder.decodeUint32(kMessageFlagsOffset);
     if (mustHaveRequestId(flags)) {
       if (_header.size < kMessageWithRequestIdSize) {
-        throw new MojoCodecError(
-            'Incorrect message size. Got: ${_header.size} '
+        throw new MojoCodecError('Incorrect message size. Got: ${_header.size} '
             'wanted $kMessageWithRequestIdSize');
       }
       requestId = decoder.decodeUint64(kMessageRequestIdOffset);
     } else {
       requestId = 0;
     }
   }
 
   int get size => _header.size;
   bool get hasRequestId => mustHaveRequestId(flags);
 
   void encode(Encoder encoder) {
     encoder.encodeStructDataHeader(_header);
     encoder.encodeUint32(type, kMessageTypeOffset);
     encoder.encodeUint32(flags, kMessageFlagsOffset);
     if (hasRequestId) {
       encoder.encodeUint64(requestId, kMessageRequestIdOffset);
     }
   }
 
-  ServiceMessage get serviceMessage => new ServiceMessage(this);
-
   String toString() => "MessageHeader($_header, $type, $flags, $requestId)";
 
   bool validateHeaderFlags(expectedFlags) =>
       (flags & (kMessageExpectsResponse | kMessageIsResponse)) == expectedFlags;
 
   bool validateHeader(int expectedType, int expectedFlags) =>
       (type == expectedType) && validateHeaderFlags(expectedFlags);
 
   static void _validateDataHeader(StructDataHeader dataHeader) {
     if (dataHeader.version < kSimpleMessageVersion) {
       throw 'Incorrect version, expecting at least '
-            '$kSimpleMessageVersion, but got: ${dataHeader.version}.';
+          '$kSimpleMessageVersion, but got: ${dataHeader.version}.';
     }
     if (dataHeader.size < kSimpleMessageSize) {
       throw 'Incorrect message size, expecting at least $kSimpleMessageSize, '
-            'but got: ${dataHeader.size}';
+          'but got: ${dataHeader.size}';
     }
     if ((dataHeader.version == kSimpleMessageVersion) &&
         (dataHeader.size != kSimpleMessageSize)) {
       throw 'Incorrect message size for a message of version '
-            '$kSimpleMessageVersion, expecting $kSimpleMessageSize, '
-            'but got ${dataHeader.size}';
+          '$kSimpleMessageVersion, expecting $kSimpleMessageSize, '
+          'but got ${dataHeader.size}';
     }
     if ((dataHeader.version == kMessageWithRequestIdVersion) &&
         (dataHeader.size != kMessageWithRequestIdSize)) {
       throw 'Incorrect message size for a message of version '
-            '$kMessageWithRequestIdVersion, expecting '
-            '$kMessageWithRequestIdSize, but got ${dataHeader.size}';
+          '$kMessageWithRequestIdVersion, expecting '
+          '$kMessageWithRequestIdSize, but got ${dataHeader.size}';
     }
   }
 }
 
-
 class Message {
   final ByteData buffer;
   final List<core.MojoHandle> handles;
   Message(this.buffer, this.handles);
   String toString() =>
       "Message(numBytes=${buffer.lengthInBytes}, numHandles=${handles.length})";
 }
 
-
 class ServiceMessage extends Message {
   final MessageHeader header;
   Message _payload;
 
   ServiceMessage(Message message, this.header)
       : super(message.buffer, message.handles);
 
   ServiceMessage.fromMessage(Message message)
       : this(message, new MessageHeader.fromMessage(message));
 
   Message get payload {
     if (_payload == null) {
       var truncatedBuffer = new ByteData.view(buffer.buffer, header.size);
       _payload = new Message(truncatedBuffer, handles);
     }
     return _payload;
   }
 
   String toString() => "ServiceMessage($header, $_payload)";
 }