Use the number of in-object properties when deciding how many fast...

src/objects.h

 // Copyright 2006-2009 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 1349 matching lines @@
 
   Object* SetFastElement(uint32_t index, Object* value);
 
   // Set the index'th array element.
   // A Failure object is returned if GC is needed.
   Object* SetElement(uint32_t index, Object* value);
 
   // Returns the index'th element.
   // The undefined object if index is out of bounds.
   Object* GetElementWithReceiver(JSObject* receiver, uint32_t index);
+  Object* GetElementWithInterceptor(JSObject* receiver, uint32_t index);
 
   Object* SetFastElementsCapacityAndLength(int capacity, int length);
   Object* SetSlowElements(Object* length);
 
   // Lookup interceptors are used for handling properties controlled by host
   // objects.
   inline bool HasNamedInterceptor();
   inline bool HasIndexedInterceptor();
 
   // Support functions for v8 api (needed for correct interceptor behavior).
@@ skipping 160 matching lines @@
     int number_of_fast_used_elements_;
     int number_of_fast_unused_elements_;
     int number_of_slow_used_elements_;
     int number_of_slow_unused_elements_;
   };
 
   void IncrementSpillStatistics(SpillInformation* info);
 #endif
   Object* SlowReverseLookup(Object* value);
 
+  // Maximal number of fast properties for the JSObject. Used to
+  // restrict the number of map transitions to avoid an explosion in
+  // the number of maps for objects used as dictionaries.
+  inline int MaxFastProperties();
+
   // Maximal number of elements (numbered 0 .. kMaxElementCount - 1).
   // Also maximal value of JSArray's length property.
   static const uint32_t kMaxElementCount = 0xffffffffu;
 
   static const uint32_t kMaxGap = 1024;
   static const int kMaxFastElementsLength = 5000;
   static const int kInitialMaxFastElementArray = 100000;
   static const int kMaxFastProperties = 8;
   static const int kMaxInstanceSize = 255 * kPointerSize;
   // When extending the backing storage for property values, we increase
   // its size by more than the 1 entry necessary, so sequentially adding fields
   // to the same object requires fewer allocations and copies.
   static const int kFieldsAdded = 3;
 
   // Layout description.
   static const int kPropertiesOffset = HeapObject::kHeaderSize;
   static const int kElementsOffset = kPropertiesOffset + kPointerSize;
   static const int kHeaderSize = kElementsOffset + kPointerSize;
 
   STATIC_CHECK(kHeaderSize == Internals::kJSObjectHeaderSize);
 
-  Object* GetElementWithInterceptor(JSObject* receiver, uint32_t index);
-
  private:
   Object* GetElementWithCallback(Object* receiver,
                                  Object* structure,
                                  uint32_t index,
                                  Object* holder);
   Object* SetElementWithCallback(Object* structure,
                                  uint32_t index,
                                  Object* value,
                                  JSObject* holder);
   Object* SetElementWithInterceptor(uint32_t index, Object* value);
@@ skipping 3751 matching lines @@
     } else {
       value &= ~(1 << bit_position);
     }
     return value;
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_H_