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

src/profile-generator.cc

Index: src/profile-generator.cc
diff --git a/src/profile-generator.cc b/src/profile-generator.cc
index 640f13cd62ceb33c227ca2e5d7101ca68ca7c2eb..1bb22be03de0409bcfb4e2c44c8cef989e5a7ae8 100644
--- a/src/profile-generator.cc
+++ b/src/profile-generator.cc
@@ -1544,6 +1544,28 @@ HeapSnapshotsDiff* HeapSnapshot::CompareWith(HeapSnapshot* 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);