Save heap object tracking data in heap snapshot

src/heap-snapshot-generator.h

 // Copyright 2013 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_HEAP_SNAPSHOT_GENERATOR_H_
 #define V8_HEAP_SNAPSHOT_GENERATOR_H_
 
 #include "src/strings-storage.h"
 
 namespace v8 {
@@ skipping 176 matching lines @@
   SnapshotObjectId max_snapshot_js_object_id_;
 
   friend class HeapSnapshotTester;
 
   DISALLOW_COPY_AND_ASSIGN(HeapSnapshot);
 };
 
 
 class HeapObjectsMap {
  public:
+  struct TimeInterval {
+    explicit TimeInterval(SnapshotObjectId id)
+        : id(id), size(0), count(0), timestamp(base::TimeTicks::Now()) {}
+    SnapshotObjectId last_assigned_id() const { return id - kObjectIdStep; }
+    SnapshotObjectId id;
+    uint32_t size;
+    uint32_t count;
+    base::TimeTicks timestamp;
+  };
+
   explicit HeapObjectsMap(Heap* heap);
 
   Heap* heap() const { return heap_; }
 
   SnapshotObjectId FindEntry(Address addr);
   SnapshotObjectId FindOrAddEntry(Address addr,
                                   unsigned int size,
                                   bool accessed = true);
   bool MoveObject(Address from, Address to, int size);
   void UpdateObjectSize(Address addr, int size);
   SnapshotObjectId last_assigned_id() const {
     return next_id_ - kObjectIdStep;
   }
 
   void StopHeapObjectsTracking();
   SnapshotObjectId PushHeapObjectsStats(OutputStream* stream);
+  const List<TimeInterval>& samples() const { return time_intervals_; }
   size_t GetUsedMemorySize() const;
 
   SnapshotObjectId GenerateId(v8::RetainedObjectInfo* info);
 
   static const int kObjectIdStep = 2;
   static const SnapshotObjectId kInternalRootObjectId;
   static const SnapshotObjectId kGcRootsObjectId;
   static const SnapshotObjectId kGcRootsFirstSubrootId;
   static const SnapshotObjectId kFirstAvailableObjectId;
 
   int FindUntrackedObjects();
 
   void UpdateHeapObjectsMap();
   void RemoveDeadEntries();
 
  private:
   struct EntryInfo {
   EntryInfo(SnapshotObjectId id, Address addr, unsigned int size)
       : id(id), addr(addr), size(size), accessed(true) { }
   EntryInfo(SnapshotObjectId id, Address addr, unsigned int size, bool accessed)
       : id(id), addr(addr), size(size), accessed(accessed) { }
     SnapshotObjectId id;
     Address addr;
     unsigned int size;
     bool accessed;
   };
-  struct TimeInterval {
-    explicit TimeInterval(SnapshotObjectId id) : id(id), size(0), count(0) { }
-    SnapshotObjectId id;
-    uint32_t size;
-    uint32_t count;
-  };
 
   SnapshotObjectId next_id_;
   HashMap entries_map_;
   List<EntryInfo> entries_;
   List<TimeInterval> time_intervals_;
   Heap* heap_;
 
   DISALLOW_COPY_AND_ASSIGN(HeapObjectsMap);
 };
 
@@ skipping 322 matching lines @@
   int entry_index(HeapEntry* e) { return e->index() * kNodeFieldsCount; }
   void SerializeEdge(HeapGraphEdge* edge, bool first_edge);
   void SerializeEdges();
   void SerializeImpl();
   void SerializeNode(HeapEntry* entry);
   void SerializeNodes();
   void SerializeSnapshot();
   void SerializeTraceTree();
   void SerializeTraceNode(AllocationTraceNode* node);
   void SerializeTraceNodeInfos();
+  void SerializeSamples();
   void SerializeString(const unsigned char* s);
   void SerializeStrings();
 
   static const int kEdgeFieldsCount;
   static const int kNodeFieldsCount;
 
   HeapSnapshot* snapshot_;
   HashMap strings_;
   int next_node_id_;
   int next_string_id_;
   OutputStreamWriter* writer_;
 
   friend class HeapSnapshotJSONSerializerEnumerator;
   friend class HeapSnapshotJSONSerializerIterator;
 
   DISALLOW_COPY_AND_ASSIGN(HeapSnapshotJSONSerializer);
 };
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_HEAP_SNAPSHOT_GENERATOR_H_