[observatory] Add an "ownership" analysis for the heap snapshot.

runtime/observatory/lib/src/elements/heap_snapshot.dart

 // Copyright (c) 2015, 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.
 
 // 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.
 
 import 'dart:async';
 import 'dart:html';
 import 'dart:math' as Math;
 import 'package:observatory/models.dart' as M;
 import 'package:observatory/src/elements/class_ref.dart';
 import 'package:observatory/src/elements/containers/virtual_tree.dart';
 import 'package:observatory/src/elements/helpers/any_ref.dart';
 import 'package:observatory/src/elements/helpers/nav_bar.dart';
 import 'package:observatory/src/elements/helpers/nav_menu.dart';
 import 'package:observatory/src/elements/helpers/rendering_scheduler.dart';
 import 'package:observatory/src/elements/helpers/tag.dart';
 import 'package:observatory/src/elements/helpers/uris.dart';
 import 'package:observatory/src/elements/nav/isolate_menu.dart';
 import 'package:observatory/src/elements/nav/notify.dart';
 import 'package:observatory/src/elements/nav/refresh.dart';
 import 'package:observatory/src/elements/nav/top_menu.dart';
 import 'package:observatory/src/elements/nav/vm_menu.dart';
 import 'package:observatory/utils.dart';
 
-enum HeapSnapshotTreeMode { dominatorTree, mergedDominatorTree, groupByClass }
+enum HeapSnapshotTreeMode {
+  dominatorTree,
+  mergedDominatorTree,
+  ownershipTable,
+  groupByClass
+}
 
 class HeapSnapshotElement extends HtmlElement implements Renderable {
   static const tag =
       const Tag<HeapSnapshotElement>('heap-snapshot', dependencies: const [
     ClassRefElement.tag,
     NavTopMenuElement.tag,
     NavVMMenuElement.tag,
     NavIsolateMenuElement.tag,
     NavRefreshElement.tag,
     NavNotifyElement.tag,
@@ skipping 248 matching lines @@
         final text = 'A heap dominator tree, where siblings with the same class'
             ' have been merged into a single node.';
         report.addAll([
           new DivElement()
             ..classes = ['content-centered-big', 'explanation']
             ..text = text
             ..title = text,
           _tree
         ]);
         break;
+      case HeapSnapshotTreeMode.ownershipTable:
+        final items = _snapshot.ownershipClasses.toList();
+        items.sort((a, b) => b.size - a.size);
+        _tree = new VirtualTreeElement(_createOwnershipClass,
+            _updateOwnershipClass, _getChildrenOwnershipClass,
+            items: items, queue: _r.queue);
+        _tree.expand(_snapshot.dominatorTree);
+        report.add(_tree);
+        break;
       case HeapSnapshotTreeMode.groupByClass:
         final items = _snapshot.classReferences.toList();
         items.sort((a, b) => b.shallowSize - a.shallowSize);
         _tree = new VirtualTreeElement(
             _createGroup, _updateGroup, _getChildrenGroup,
             items: items, queue: _r.queue);
         _tree.expand(_snapshot.dominatorTree);
         report.add(_tree);
         break;
       default:
@@ skipping 49 matching lines @@
         new ButtonElement()
           ..classes = ['expander']
           ..onClick.listen((_) => toggle(autoToggleSingleChildNodes: true)),
         new SpanElement()
           ..classes = ['count']
           ..title = 'shallow size',
         new SpanElement()..classes = ['name']
       ];
   }
 
+  static Element _createOwnershipClass(toggle) {
+    return new DivElement()
+      ..classes = ['tree-item']
+      ..children = [
+        new SpanElement()
+          ..classes = ['size']
+          ..title = 'size',
+        new SpanElement()..classes = ['name']
+      ];
+  }
+
   static const int kMaxChildren = 100;
   static const int kMinRetainedSize = 4096;
 
   static _getChildrenDominator(M.HeapSnapshotDominatorNode node) {
     final list = node.children.toList();
     list.sort((a, b) => b.retainedSize - a.retainedSize);
     return list
         .where((child) => child.retainedSize >= kMinRetainedSize)
         .take(kMaxChildren);
   }
@@ skipping 10 matching lines @@
     if (item is M.HeapSnapshotClassReferences) {
       if (item.inbounds.isNotEmpty || item.outbounds.isNotEmpty) {
         return [item.inbounds, item.outbounds];
       }
     } else if (item is Iterable) {
       return item.toList()..sort((a, b) => b.shallowSize - a.shallowSize);
     }
     return const [];
   }
 
+  static _getChildrenOwnershipClass(item) {
+    return const [];
+  }
+
   void _updateDominator(
       HtmlElement element, M.HeapSnapshotDominatorNode node, int depth) {
     element.children[0].text = Utils.formatSize(node.retainedSize);
     _updateLines(element.children[1].children, depth);
     if (_getChildrenDominator(node).isNotEmpty) {
       element.children[2].text = _tree.isExpanded(node) ? '▼' : '►';
     } else {
       element.children[2].text = '';
     }
     element.children[3].text =
@@ skipping 97 matching lines @@
         ];
       } else if (item is M.HeapSnapshotClassOutbound) {
         element.children[3]..text = '${item.count} references to instances of ';
         element.children[4].children = [
           new ClassRefElement(_isolate, item.target, queue: _r.queue)
         ];
       }
     }
   }
 
+  void _updateOwnershipClass(HtmlElement element, item, int depth) {
+    _updateLines(element.children[1].children, depth);
+    element.children[0].text = Utils.formatSize(item.size);
+    element.children[1] =
+        new ClassRefElement(_isolate, item.clazz, queue: _r.queue)
+          ..classes = ['name'];
+  }
+
   static _updateLines(List<Element> lines, int n) {
     n = Math.max(0, n);
     while (lines.length > n) {
       lines.removeLast();
     }
     while (lines.length < n) {
       lines.add(new SpanElement());
     }
   }
 
@@ skipping 24 matching lines @@
         })
     ];
   }
 
   static String modeToString(HeapSnapshotTreeMode mode) {
     switch (mode) {
       case HeapSnapshotTreeMode.dominatorTree:
         return 'Dominator tree';
       case HeapSnapshotTreeMode.mergedDominatorTree:
         return 'Dominator tree (merged siblings by class)';
+      case HeapSnapshotTreeMode.ownershipTable:
+        return 'Ownership table';
       case HeapSnapshotTreeMode.groupByClass:
         return 'Group by class';
     }
     throw new Exception('Unknown HeapSnapshotTreeMode');
   }
 
   List<Element> _createModeSelect() {
     var s;
     return [
       s = new SelectElement()
         ..classes = ['analysis-select']
         ..value = modeToString(_mode)
         ..children = HeapSnapshotTreeMode.values.map((mode) {
           return new OptionElement(
               value: modeToString(mode), selected: _mode == mode)
             ..text = modeToString(mode);
         }).toList(growable: false)
         ..onChange.listen((_) {
           _mode = HeapSnapshotTreeMode.values[s.selectedIndex];
           _r.dirty();
         })
     ];
   }
 }