Converted Observatory heap-profile element

runtime/observatory/lib/src/app/application.dart

 // 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.
 
 part of app;
 
 /// The observatory application. Instances of this are created and owned
 /// by the observatory_application custom element.
 class ObservatoryApplication extends Observable {
   static ObservatoryApplication app;
   final RenderingQueue queue = new RenderingQueue();
   final TargetRepository targets = new TargetRepository();
   final EventRepository events = new EventRepository();
   final NotificationRepository notifications = new NotificationRepository();
   final _pageRegistry = new List<Page>();
   LocationManager _locationManager;
   LocationManager get locationManager => _locationManager;
   @observable Page currentPage;
   VM _vm;
   VM get vm => _vm;
 
   _setVM(VM vm) {
     if (_vm == vm) {
       // Do nothing.
       return;
     }
     if (_vm != null) {
+      _gcSubscription = null;
       // Disconnect from current VM.
       notifications.deleteAll();
       _vm.disconnect();
     }
     if (vm != null) {
       Logger.root.info('Registering new VM callbacks');
 
       vm.onConnect.then((_) {
         notifications.deleteDisconnectEvents();
       });
 
       vm.onDisconnect.then((String reason) {
         if (this.vm != vm) {
           // This disconnect event occured *after* a new VM was installed.
           return;
         }
         events.add(new ConnectionClosedEvent(new DateTime.now(), reason));
       });
 
       // TODO(cbernaschina) smart connection of streams in the events object.
       vm.listenEventStream(VM.kVMStream, _onEvent);
       vm.listenEventStream(VM.kIsolateStream, _onEvent);
       vm.listenEventStream(VM.kDebugStream, _onEvent);
     }
     _vm = vm;
   }
+
+  StreamSubscription _gcSubscription;
+
+  Future startGCEventListener() async {
+    if (_gcSubscription != null || _vm == null) {
+      return;
+    }
+    _gcSubscription = await _vm.listenEventStream(VM.kGCStream, _onEvent);
+  }
+
+  Future stopGCEventListener() async {
+    if (_gcSubscription == null) {
+      return;
+    }
+    _gcSubscription.cancel();
+    _gcSubscription = null;
+  }
+
+
   @reflectable final ObservatoryApplicationElement rootElement;
 
   TraceViewElement _traceView = null;
 
   @reflectable ServiceObject lastErrorOrException;
 
   void _initOnce() {
     assert(app == null);
     app = this;
     _registerPages();
@@ skipping 67 matching lines @@
             event.topFrame, event.atAsyncSuspension);
         break;
       case ServiceEvent.kPauseException:
         e = new PauseExceptionEvent(event.timestamp, event.isolate,
             event.topFrame, event.exception);
         break;
       case ServiceEvent.kInspect:
         e = new InspectEvent(event.timestamp, event.isolate,
             event.inspectee);
         break;
+      case ServiceEvent.kGC:
+        e = new GCEvent(event.timestamp, event.isolate);
+        break;
       default:
         // Ignore unrecognized events.
         Logger.root.severe('Unrecognized event: $event');
         return;
     }
     events.add(e);
   }
 
   void _registerPages() {
     _pageRegistry.add(new VMPage(this));
@@ skipping 120 matching lines @@
     }
 
     // TODO(turnidge): Report this failure via analytics.
     Logger.root.warning('Caught exception: ${e}\n${st}');
     notifications.add(new ExceptionNotification(e, stacktrace: st));
   }
 
   // This map keeps track of which curly-blocks have been expanded by the user.
   Map<String,bool> expansions = {};
 }