New Heap Profiler: add API method for finding a graph node by id.

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 1526 matching lines @@
          (raw_entries_ + raw_entries_size_));
   return entries_.last();
 }
 
 
 HeapSnapshotsDiff* HeapSnapshot::CompareWith(HeapSnapshot* snapshot) {
   return collection_->CompareSnapshots(this, snapshot);
 }
 
 
+HeapEntry* HeapSnapshot::GetEntryById(uint64_t id) {
+  // GetSortedEntriesList is used in diff algorithm and sorts
+  // entries by their id.
+  List<HeapEntry*>* entries_by_id = GetSortedEntriesList();
+
+  // Perform a binary search by id.
+  int low = 0;
+  int high = entries_by_id->length() - 1;
+  while (low <= high) {
+    int mid = ((unsigned int)low + (unsigned int)high) >> 1;

[Søren Thygesen Gjesse, 2010/12/02 07:37:15]

No C-style casts please.

[mnaganov (inactive), 2010/12/02 15:38:25]

Done.

+    uint64_t mid_id = entries_by_id->at(mid)->id();
+    if (mid_id > id)
+      high = mid - 1;
+    else if (mid_id < id)
+      low = mid + 1;
+    else
+      return entries_by_id->at(mid);
+  }
+  return NULL;
+}
+
+
 List<HeapGraphPath*>* HeapSnapshot::GetRetainingPaths(HeapEntry* entry) {
   HashMap::Entry* p =
       retaining_paths_.Lookup(entry, HeapEntry::Hash(entry), true);
   if (p->value == NULL) {
     p->value = entry->CalculateRetainingPaths();
   }
   return reinterpret_cast<List<HeapGraphPath*>*>(p->value);
 }
 
 
@@ skipping 1214 matching lines @@
 
 
 String* GetConstructorNameForHeapProfile(JSObject* object) {
   if (object->IsJSFunction()) return Heap::closure_symbol();
   return object->constructor_name();
 }
 
 } }  // namespace v8::internal
 
 #endif  // ENABLE_LOGGING_AND_PROFILING