Limit initial size of hidden properties and store identity hashes inline.

src/objects.h

 // Copyright 2012 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 1713 matching lines @@
   // otherwise returns the value set for the key.
   Object* GetHiddenProperty(String* key);
   // Deletes a hidden property. Deleting a non-existing property is
   // considered successful.
   void DeleteHiddenProperty(String* key);
   // Returns true if the object has a property with the hidden symbol as name.
   bool HasHiddenProperties();
 
   static int GetIdentityHash(Handle<JSObject> obj);
   MUST_USE_RESULT MaybeObject* GetIdentityHash(CreationFlag flag);
-  MUST_USE_RESULT MaybeObject* SetIdentityHash(Object* hash, CreationFlag flag);
+  MUST_USE_RESULT MaybeObject* SetIdentityHash(Smi* hash, CreationFlag flag);
 
   static Handle<Object> DeleteProperty(Handle<JSObject> obj,
                                        Handle<String> name);
   MUST_USE_RESULT MaybeObject* DeleteProperty(String* name, DeleteMode mode);
 
   static Handle<Object> DeleteElement(Handle<JSObject> obj, uint32_t index);
   MUST_USE_RESULT MaybeObject* DeleteElement(uint32_t index, DeleteMode mode);
 
   inline void ValidateElements();
 
@@ skipping 483 matching lines @@
       Object* getter,
       Object* setter,
       PropertyAttributes attributes);
   MUST_USE_RESULT MaybeObject* CreateAccessorPairFor(String* name);
   MUST_USE_RESULT MaybeObject* DefinePropertyAccessor(
       String* name,
       Object* getter,
       Object* setter,
       PropertyAttributes attributes);
 
-  // Returns the hidden properties backing store object, currently
-  // a StringDictionary, stored on this object.
-  // If no hidden properties object has been put on this object,
-  // return undefined, unless create_if_absent is true, in which case
-  // a new dictionary is created, added to this object, and returned.
-  MUST_USE_RESULT MaybeObject* GetHiddenPropertiesDictionary(
+  // If create_if_absent is true, return the hash table backing store
+  // for hidden properties.  If there is no backing store, allocate one.
+  // If create_if_absent is false, return the hash table backing store
+  // or the inline stored identity hash, whatever is found.
+  MUST_USE_RESULT MaybeObject* GetHiddenPropertiesHashTable(
       bool create_if_absent);
-  // Updates the existing hidden properties dictionary.
-  MUST_USE_RESULT MaybeObject* SetHiddenPropertiesDictionary(
-      StringDictionary* dictionary);
+  // Set the hidden property backing store to either a hash table or
+  // the inline-stored identity hash.
+  MUST_USE_RESULT MaybeObject* SetHiddenPropertiesHashTable(
+      Object* hidden);
 
   DISALLOW_IMPLICIT_CONSTRUCTORS(JSObject);
 };
 
 
 // Common superclass for FixedArrays that allow implementations to share
 // common accessors and some code paths.
 class FixedArrayBase: public HeapObject {
  public:
   // [length]: length of the array.
@@ skipping 534 matching lines @@
     SetNumberOfDeletedElements(NumberOfDeletedElements() + 1);
   }
   void ElementsRemoved(int n) {
     SetNumberOfElements(NumberOfElements() - n);
     SetNumberOfDeletedElements(NumberOfDeletedElements() + n);
   }
 
   // Returns a new HashTable object. Might return Failure.
   MUST_USE_RESULT static MaybeObject* Allocate(
       int at_least_space_for,
+      bool force_capacity = false,

[Toon Verwaest, 2012/07/30 09:13:24]

Can this be an enum?

       PretenureFlag pretenure = NOT_TENURED);
 
   // Computes the required capacity for a table holding the given
   // number of elements. May be more than HashTable::kMaxCapacity.
   static int ComputeCapacity(int at_least_space_for);
 
   // Returns the key at entry.
   Object* KeyAt(int entry) { return get(EntryToIndex(entry)); }
 
   // Tells whether k is a real key.  The hole and undefined are not allowed
@@ skipping 6098 matching lines @@
     } else {
       value &= ~(1 << bit_position);
     }
     return value;
   }
 };
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_H_