Implement a hash based look-up to speed up containing address check in large

src/spaces.h

 // Copyright 2011 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 11 matching lines @@
 // LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
 // DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
 // THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
 // (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
 // OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
 
 #ifndef V8_SPACES_H_
 #define V8_SPACES_H_
 
 #include "allocation.h"
+#include "hashmap.h"
 #include "list.h"
 #include "log.h"
 
 namespace v8 {
 namespace internal {
 
 class Isolate;
 
 // -----------------------------------------------------------------------------
 // Heap structures:
@@ skipping 2450 matching lines @@
 
   int PageCount() {
     return page_count_;
   }
 
   // Finds an object for a given address, returns Failure::Exception()
   // if it is not found. The function iterates through all objects in this
   // space, may be slow.
   MaybeObject* FindObject(Address a);
 
-  // Finds a large object page containing the given pc, returns NULL
+  // Finds a large object page containing the given address, returns NULL
   // if such a page doesn't exist.
-  LargePage* FindPageContainingPc(Address pc);
+  LargePage* FindPage(Address a);
 
   // Frees unmarked objects.
   void FreeUnmarkedObjects();
 
   // Checks whether a heap object is in this space; O(1).
   bool Contains(HeapObject* obj);
 
   // Checks whether the space is empty.
   bool IsEmpty() { return first_page_ == NULL; }
 
@@ skipping 14 matching lines @@
   // iterates all objects in the space. May be slow.
   bool SlowContains(Address addr) { return !FindObject(addr)->IsFailure(); }
 
  private:
   intptr_t max_capacity_;
   // The head of the linked list of large object chunks.
   LargePage* first_page_;
   intptr_t size_;  // allocated bytes
   int page_count_;  // number of chunks
   intptr_t objects_size_;  // size of objects
+  // Map MemoryChunk::kAlignment-aligned chunks to large pages covering them
+  HashMap chunk_map_;
 
   friend class LargeObjectIterator;
 
  public:
   TRACK_MEMORY("LargeObjectSpace")
 };
 
 
 class LargeObjectIterator: public ObjectIterator {
  public:
@@ skipping 84 matching lines @@
   }
   // Must be small, since an iteration is used for lookup.
   static const int kMaxComments = 64;
 };
 #endif
 
 
 } }  // namespace v8::internal
 
 #endif  // V8_SPACES_H_