Add class and address information to heap map; display on hover.

runtime/vm/pages.cc

 // Copyright (c) 2012, 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.
 
 #include "vm/pages.h"
 
 #include "platform/assert.h"
 #include "vm/compiler_stats.h"
 #include "vm/gc_marker.h"
 #include "vm/gc_sweeper.h"
@@ skipping 423 matching lines @@
       : ObjectVisitor(NULL), array_(array) {}
   virtual void VisitObject(RawObject* obj) {
     array_->AddValue(obj->Size() / kObjectAlignment);
     array_->AddValue(obj->GetClassId());
   }
  private:
   JSONArray* array_;
 };
 
 
-void PageSpace::PrintHeapMapToJSONStream(JSONStream* stream) {
+void PageSpace::PrintHeapMapToJSONStream(Isolate* isolate, JSONStream* stream) {
   JSONObject heap_map(stream);
   heap_map.AddProperty("type", "HeapMap");
   heap_map.AddProperty("id", "heapmap");
   heap_map.AddProperty("free_class_id",
                        static_cast<intptr_t>(kFreeListElement));
   heap_map.AddProperty("unit_size_bytes",
                        static_cast<intptr_t>(kObjectAlignment));
+  heap_map.AddProperty("page_size_bytes", kPageSizeInWords * kWordSize);
   {
-    // "pages" is an array [page0, page1, ..., pageN], each page an array
-    // [size, class id, size, class id, ...] (size unit is kObjectAlignment).
+    JSONObject class_list(&heap_map, "class_list");
+    isolate->class_table()->PrintToJSONObject(&class_list);
+  }
+  {
+    // "pages" is an array [page0, page1, ..., pageN], each page of the form
+    // {"object_start": "0x...", "objects": [size, class id, size, ...]}
     JSONArray all_pages(&heap_map, "pages");
     for (HeapPage* page = pages_; page != NULL; page = page->next()) {
-      JSONArray page_map(&all_pages);
+      JSONObject page_container(&all_pages);
+      page_container.AddPropertyF("object_start",
+                                  "0x%" Px "", page->object_start());
+      JSONArray page_map(&page_container, "objects");
       HeapMapAsJSONVisitor printer(&page_map);
       page->VisitObjects(&printer);
     }
   }
 }
 
 
 bool PageSpace::ShouldCollectCode() {
   // Try to collect code if enough time has passed since the last attempt.
   const int64_t start = OS::GetCurrentTimeMicros();
@@ skipping 269 matching lines @@
     return 0;
   } else {
     ASSERT(total_time >= gc_time);
     int result= static_cast<int>((static_cast<double>(gc_time) /
                              static_cast<double>(total_time)) * 100);
     return result;
   }
 }
 
 }  // namespace dart