observatory: optionally auto-refresh allocation profile page at each GC.

runtime/bin/vmservice/observatory/lib/src/elements/heap_profile.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 heap_profile_element;
 
 import 'dart:html';
 import 'observatory_element.dart';
 import 'package:observatory/app.dart';
 import 'package:observatory/service.dart';
@@ skipping 25 matching lines @@
   var _newPieChart;
 
   // Pie chart of old space usage.
   var _oldPieDataTable;
   var _oldPieChart;
 
   @observable ClassSortedTable classTable;
   var _classTableBody;
 
   @published ServiceMap profile;
+  @published bool autoRefresh = false;
+  var _subscription;
 
   @observable Isolate isolate;
 
   HeapProfileElement.created() : super.created() {
     // Create pie chart models.
     _newPieDataTable = new DataTable();
     _newPieDataTable.addColumn('string', 'Type');
     _newPieDataTable.addColumn('number', 'Size');
     _oldPieDataTable = new DataTable();
     _oldPieDataTable.addColumn('string', 'Type');
@@ skipping 28 matching lines @@
 
   @override
   void attached() {
     super.attached();
     // Grab the pie chart divs.
     _newPieChart = new Chart('PieChart',
         shadowRoot.querySelector('#newPieChart'));
     _oldPieChart = new Chart('PieChart',
         shadowRoot.querySelector('#oldPieChart'));
     _classTableBody = shadowRoot.querySelector('#classTableBody');
+    _subscription = app.vm.events.stream.where(
+        (event) => event.isolate == isolate).listen(_onEvent);
   }
 
+  @override
+  void detached() {
+    _subscription.cancel((){});
+    super.detached();
+  }
+  
+  void _onEvent(ServiceEvent event) {
+    if (autoRefresh && event.eventType == 'GC') {
+      refresh((){});
+    }
+  }
+  
   void _updatePieCharts() {
     assert(profile != null);
     _newPieDataTable.clearRows();
     var isolate = profile.isolate;
     _newPieDataTable.addRow(['Used', isolate.newSpace.used]);
     _newPieDataTable.addRow(['Free',
         isolate.newSpace.capacity - isolate.newSpace.used]);
     _newPieDataTable.addRow(['External', isolate.newSpace.external]);
     _oldPieDataTable.clearRows();
     _oldPieDataTable.addRow(['Used', isolate.oldSpace.used]);
@@ skipping 210 matching lines @@
   }
 
   @observable String formattedTotalCollectionTime(bool newSpace) {
     if (profile == null) {
       return '';
     }
     var heap = newSpace ? profile.isolate.newSpace : profile.isolate.oldSpace;
     return '${Utils.formatSeconds(heap.totalCollectionTimeInSeconds)} secs';
   }
 }