Optional binary payloads in VM service events.

runtime/bin/vmservice/observatory/lib/service_common.dart

 // Copyright (c) 2014, 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 service_common;
 
 import 'dart:async';
 import 'dart:convert';
+import 'dart:typed_data';
 
 import 'package:logging/logging.dart';
 import 'package:observatory/service.dart';
 
 // Export the service library.
 export 'package:observatory/service.dart';
 
 /// Description of a VM target.
 class WebSocketVMTarget {
   // Last time this VM has been connected to.
@@ skipping 43 matching lines @@
 /// Minimal common interface for 'WebSocket' in [dart:io] and [dart:html].
 abstract class CommonWebSocket {
   void connect(String address,
                void onOpen(),
                void onMessage(dynamic data),
                void onError(),
                void onClose());
   bool get isOpen;
   void send(dynamic data);
   void close();
+  Future<ByteData> nonStringToByteData(dynamic data);
 }
 
 /// A [CommonWebSocketVM] communicates with a Dart VM over a CommonWebSocket.
 /// The Dart VM can be embedded in Chromium or standalone. In the case of
 /// Chromium, we make the service requests via the Chrome Remote Debugging
 /// Protocol.
 abstract class CommonWebSocketVM extends VM {
   final Completer _connected = new Completer();
   final Completer _disconnected = new Completer();
   final WebSocketVMTarget target;
   final Map<String, _WebSocketRequest> _delayedRequests =
         new Map<String, _WebSocketRequest>();
   final Map<String, _WebSocketRequest> _pendingRequests =
       new Map<String, _WebSocketRequest>();
   int _requestSerial = 0;
   bool _hasInitiatedConnect = false;
+  Utf8Decoder _utf8Decoder = new Utf8Decoder();
 
   CommonWebSocket _webSocket;
 
   CommonWebSocketVM(this.target, this._webSocket) {
     assert(target != null);
   }
 
   void _notifyConnect() {
     if (!_connected.isCompleted) {
       Logger.root.info('WebSocketVM connection opened: ${target.networkAddress}');
@@ skipping 55 matching lines @@
 
   // WebSocket open event handler.
   void _onOpen() {
     target.lastConnectionTime = new DateTime.now().millisecondsSinceEpoch;
     _sendAllDelayedRequests();
     _notifyConnect();
   }
 
   // WebSocket message event handler.
   void _onMessage(dynamic data) {
-    assert(data is String);  // We don't handle binary data, yet.
+    if (data is! String) {
+      _webSocket.nonStringToByteData(data).then((ByteData bytes) {
+        // See format spec. in VMs Service::SendEvent.
+        int offset = 0;
+        int metaSize = bytes.getUint64(offset, Endianness.BIG_ENDIAN);
+        offset += 8;
+        var meta = _utf8Decoder.convert(new Uint8List.view(
+            bytes.buffer, bytes.offsetInBytes + offset, metaSize));
+        offset += metaSize;
+        var data = new ByteData.view(
+            bytes.buffer,
+            bytes.offsetInBytes + offset,
+            bytes.lengthInBytes - offset);
+        postEventMessage(meta, data);
+      });
+      return;
+    }
     var map = JSON.decode(data);
     if (map == null) {
       Logger.root.severe('WebSocketVM got empty message');
       return;
     }
     // Extract serial and response.
     var serial;
     var response;
     if (target.chrome) {
       if (map['method'] != 'Dart.observatoryData') {
@@ skipping 83 matching lines @@
           'query': request.id
         }
       });
     } else {
       message = JSON.encode({'seq': serial, 'request': request.id});
     }
     // Send message.
     _webSocket.send(message);
   }
 }