Fix HeapSnapshotsDiff test, diff implementation, and a bug introduced

src/profile-generator.cc

 // Copyright 2010 the V8 project authors. All rights reserved.
 // Redistribution and use in source and binary forms, with or without
 // modification, are permitted provided that the following conditions are
 // met:
 //
 //     * Redistributions of source code must retain the above copyright
 //       notice, this list of conditions and the following disclaimer.
 //     * Redistributions in binary form must reproduce the above
 //       copyright notice, this list of conditions and the following
 //       disclaimer in the documentation and/or other materials provided
@@ skipping 934 matching lines @@
   void Apply(HeapEntry* entry) { }
 };
 
 void HeapEntry::PaintAllReachable() {
   NullClass null;
   ApplyAndPaintAllReachable(&null);
 }
 
 
 void HeapEntry::Print(int max_depth, int indent) {
-  OS::Print("%6d %6d %6d [%ld] ",
+  OS::Print("%6d %6d %6d [%llu] ",
             self_size(), ReachableSize(), RetainedSize(), id_);
   if (type() != kString) {
     OS::Print("%s %.40s\n", TypeAsString(), name_);
   } else {
     OS::Print("\"");
     const char* c = name_;
     while (*c && (c - name_) <= 40) {
       if (*c != '\n')
         OS::Print("%c", *c);
       else
@@ skipping 264 matching lines @@
 }  // namespace
 
 HeapSnapshot::HeapSnapshot(HeapSnapshotsCollection* collection,
                            HeapSnapshot::Type type,
                            const char* title,
                            unsigned uid)
     : collection_(collection),
       type_(type),
       title_(title),
       uid_(uid),
-      root_entry_index_(-1),
+      root_entry_(NULL),
       raw_entries_(NULL),
       entries_sorted_(false) {
   STATIC_ASSERT(
       sizeof(HeapGraphEdge) ==
       SnapshotSizeConstants<sizeof(void*)>::kExpectedHeapGraphEdgeSize);  // NOLINT
   STATIC_ASSERT(
       sizeof(HeapEntry) ==
       SnapshotSizeConstants<sizeof(void*)>::kExpectedHeapEntrySize);  // NOLINT
 }
 
@@ skipping 18 matching lines @@
   raw_entries_size_ =
       HeapEntry::EntriesSize(entries_count, children_count, retainers_count);
 #endif
 }
 
 
 HeapEntry* HeapSnapshot::AddEntry(HeapObject* object,
                                   int children_count,
                                   int retainers_count) {
   if (object == kInternalRootObject) {
-    ASSERT(root_entry_index_ == -1);
-    root_entry_index_ = entries_.length();
+    ASSERT(root_entry_ == NULL);
     ASSERT(retainers_count == 0);
-    return AddEntry(
+    root_entry_ = AddEntry(
         HeapEntry::kInternal, "", 0, 0, children_count, retainers_count);
+    return root_entry_;
   } else if (object->IsJSFunction()) {
     JSFunction* func = JSFunction::cast(object);
     SharedFunctionInfo* shared = func->shared();
     String* name = String::cast(shared->name())->length() > 0 ?
         String::cast(shared->name()) : shared->inferred_name();
     return AddEntry(object,
                     HeapEntry::kClosure,
                     collection_->GetFunctionName(name),
                     children_count,
                     retainers_count);
@@ skipping 794 matching lines @@
   delete *diff_ptr;
 }
 
 HeapSnapshotsComparator::~HeapSnapshotsComparator() {
   diffs_.Iterate(DeleteHeapSnapshotsDiff);
 }
 
 
 HeapSnapshotsDiff* HeapSnapshotsComparator::Compare(HeapSnapshot* snapshot1,
                                                     HeapSnapshot* snapshot2) {
+  snapshot1->ClearPaint();
+  snapshot1->root()->PaintAllReachable();
+  snapshot2->ClearPaint();
+  snapshot2->root()->PaintAllReachable();
+  
   List<HeapEntry*>* entries1 = snapshot1->GetSortedEntriesList();
   List<HeapEntry*>* entries2 = snapshot2->GetSortedEntriesList();
   int i = 0, j = 0;
   List<HeapEntry*> added_entries, deleted_entries;
   while (i < entries1->length() && j < entries2->length()) {
     uint64_t id1 = entries1->at(i)->id();
     uint64_t id2 = entries2->at(j)->id();
     if (id1 == id2) {
-      i++;
-      j++;
+      HeapEntry* entry1 = entries1->at(i++);
+      HeapEntry* entry2 = entries2->at(j++);
+      if (entry1->painted_reachable() != entry2->painted_reachable()) {
+        if (entry1->painted_reachable())
+          deleted_entries.Add(entry1);
+        else
+          added_entries.Add(entry2);
+      }
     } else if (id1 < id2) {
       HeapEntry* entry = entries1->at(i++);
       deleted_entries.Add(entry);
     } else {
       HeapEntry* entry = entries2->at(j++);
       added_entries.Add(entry);
     }
   }
   while (i < entries1->length()) {
     HeapEntry* entry = entries1->at(i++);
     deleted_entries.Add(entry);
   }
   while (j < entries2->length()) {
     HeapEntry* entry = entries2->at(j++);
     added_entries.Add(entry);
   }
 
-  snapshot1->ClearPaint();
-  snapshot1->root()->PaintAllReachable();
-  snapshot2->ClearPaint();
-  snapshot2->root()->PaintAllReachable();
-  int reachable_deleted_entries = 0, reachable_added_entries = 0;
-  for (int i = 0; i < deleted_entries.length(); ++i) {
-    HeapEntry* entry = deleted_entries[i];
-    if (entry->painted_reachable()) ++reachable_deleted_entries;
-  }
-  for (int i = 0; i < added_entries.length(); ++i) {
-    HeapEntry* entry = added_entries[i];
-    if (entry->painted_reachable()) ++reachable_added_entries;
-  }
-
   HeapSnapshotsDiff* diff = new HeapSnapshotsDiff(snapshot1, snapshot2);
   diffs_.Add(diff);
-  diff->CreateRoots(reachable_added_entries, reachable_deleted_entries);
+  diff->CreateRoots(added_entries.length(), deleted_entries.length());
 
-  int del_child_index = 0, deleted_entry_index = 1;
   for (int i = 0; i < deleted_entries.length(); ++i) {
     HeapEntry* entry = deleted_entries[i];
-    if (entry->painted_reachable())
-      diff->AddDeletedEntry(del_child_index++, deleted_entry_index++, entry);
+    diff->AddDeletedEntry(i, i + 1, entry);
   }
-  int add_child_index = 0, added_entry_index = 1;
   for (int i = 0; i < added_entries.length(); ++i) {
     HeapEntry* entry = added_entries[i];
-    if (entry->painted_reachable())
-      diff->AddAddedEntry(add_child_index++, added_entry_index++, entry);
+    diff->AddAddedEntry(i, i + 1, entry);
   }
   return diff;
 }
 
 
 class OutputStreamWriter {
  public:
   explicit OutputStreamWriter(v8::OutputStream* stream)
       : stream_(stream),
         chunk_size_(stream->GetChunkSize()),
@@ skipping 338 matching lines @@
 void HeapSnapshotJSONSerializer::SortHashMap(
     HashMap* map, List<HashMap::Entry*>* sorted_entries) {
   for (HashMap::Entry* p = map->Start(); p != NULL; p = map->Next(p))
     sorted_entries->Add(p);
   sorted_entries->Sort(SortUsingEntryValue);
 }
 
 } }  // namespace v8::internal
 
 #endif  // ENABLE_LOGGING_AND_PROFILING