Introduce {FAST,SLOW}_STRING_WRAPPER_ELEMENTS

src/elements.h

 // Copyright 2012 the V8 project authors. All rights reserved.
 // Use of this source code is governed by a BSD-style license that can be
 // found in the LICENSE file.
 
 #ifndef V8_ELEMENTS_H_
 #define V8_ELEMENTS_H_
 
 #include "src/elements-kind.h"
 #include "src/heap/heap.h"
 #include "src/isolate.h"
@@ skipping 11 matching lines @@
   virtual ~ElementsAccessor() { }
 
   const char* name() const { return name_; }
 
   // Returns a shared ElementsAccessor for the specified ElementsKind.
   static ElementsAccessor* ForKind(ElementsKind elements_kind) {
     DCHECK(static_cast<int>(elements_kind) < kElementsKindCount);
     return elements_accessors_[elements_kind];
   }
 
-  static ElementsAccessor* ForArray(Handle<FixedArrayBase> array);
-
   // Checks the elements of an object for consistency, asserting when a problem
   // is found.
   virtual void Validate(Handle<JSObject> obj) = 0;
 
   // Returns true if a holder contains an element with the specified index
   // without iterating up the prototype chain.  The caller can optionally pass
   // in the backing store to use for the check, which must be compatible with
   // the ElementsKind of the ElementsAccessor. If backing_store is NULL, the
   // holder->elements() is used as the backing store. If a |filter| is
   // specified the PropertyAttributes of the element at the given index
   // are compared to the given |filter|. If they match/overlap the given
   // index is ignored. Note that only Dictionary elements have custom
   // PropertyAttributes associated, hence the |filter| argument is ignored for
   // all but DICTIONARY_ELEMENTS and SLOW_SLOPPY_ARGUMENTS_ELEMENTS.
   virtual bool HasElement(Handle<JSObject> holder, uint32_t index,
                           Handle<FixedArrayBase> backing_store,
                           PropertyFilter filter = ALL_PROPERTIES) = 0;
 
   inline bool HasElement(Handle<JSObject> holder, uint32_t index,
                          PropertyFilter filter = ALL_PROPERTIES) {
     return HasElement(holder, index, handle(holder->elements()), filter);
   }
 
   // Returns true if the backing store is compact in the given range
   virtual bool IsPacked(Handle<JSObject> holder,
                         Handle<FixedArrayBase> backing_store, uint32_t start,
                         uint32_t end) = 0;
 
-  virtual Handle<Object> Get(Handle<FixedArrayBase> backing_store,
-                             uint32_t entry) = 0;
+  virtual Handle<Object> Get(Handle<JSObject> holder, uint32_t entry) = 0;
+
+  virtual PropertyDetails GetDetails(JSObject* holder, uint32_t entry) = 0;
 
   // Modifies the length data property as specified for JSArrays and resizes the
   // underlying backing store accordingly. The method honors the semantics of
   // changing array sizes as defined in EcmaScript 5.1 15.4.5.2, i.e. array that
   // have non-deletable elements can only be shrunk to the size of highest
   // element that is non-deletable.
   virtual void SetLength(Handle<JSArray> holder, uint32_t new_length) = 0;
 
   // Deletes an element in an object.
   virtual void Delete(Handle<JSObject> holder, uint32_t entry) = 0;
 
   // If kCopyToEnd is specified as the copy_size to CopyElements, it copies all
   // of elements from source after source_start to the destination array.
   static const int kCopyToEnd = -1;
   // If kCopyToEndAndInitializeToHole is specified as the copy_size to
   // CopyElements, it copies all of elements from source after source_start to
   // destination array, padding any remaining uninitialized elements in the
   // destination array with the hole.
   static const int kCopyToEndAndInitializeToHole = -2;
 
-  // Copy elements from one backing store to another. Typically, callers specify
-  // the source JSObject or JSArray in source_holder. If the holder's backing
-  // store is available, it can be passed in source and source_holder is
-  // ignored.
-  virtual void CopyElements(
-      Handle<FixedArrayBase> source,
-      uint32_t source_start,
-      ElementsKind source_kind,
-      Handle<FixedArrayBase> destination,
-      uint32_t destination_start,
-      int copy_size) = 0;
-
-  // NOTE: this method violates the handlified function signature convention:
-  // raw pointer parameter |source_holder| in the function that allocates.
-  // This is done intentionally to avoid ArrayConcat() builtin performance
-  // degradation.
-  virtual void CopyElements(
-      JSObject* source_holder,
-      uint32_t source_start,
-      ElementsKind source_kind,
-      Handle<FixedArrayBase> destination,
-      uint32_t destination_start,
-      int copy_size) = 0;
-
-  inline void CopyElements(
-      Handle<JSObject> from_holder,
-      Handle<FixedArrayBase> to,
-      ElementsKind from_kind) {
-    CopyElements(
-      *from_holder, 0, from_kind, to, 0, kCopyToEndAndInitializeToHole);
-  }
-
   // Copy all indices that have elements from |object| into the given
   // KeyAccumulator. For Dictionary-based element-kinds we filter out elements
   // whose PropertyAttribute match |filter|.
   virtual void CollectElementIndices(Handle<JSObject> object,
                                      Handle<FixedArrayBase> backing_store,
                                      KeyAccumulator* keys,
                                      uint32_t range = kMaxUInt32,
                                      PropertyFilter filter = ALL_PROPERTIES,
                                      uint32_t offset = 0) = 0;
 
   inline void CollectElementIndices(Handle<JSObject> object,
                                     KeyAccumulator* keys,
                                     uint32_t range = kMaxUInt32,
                                     PropertyFilter filter = ALL_PROPERTIES,
                                     uint32_t offset = 0) {
     CollectElementIndices(object, handle(object->elements()), keys, range,
                           filter, offset);
   }
 
   virtual void AddElementsToKeyAccumulator(Handle<JSObject> receiver,
                                            KeyAccumulator* accumulator,
                                            AddKeyConversion convert) = 0;
 
   virtual void GrowCapacityAndConvert(Handle<JSObject> object,
                                       uint32_t capacity) = 0;
 
   static void InitializeOncePerProcess();
   static void TearDown();
 
-  virtual void Set(FixedArrayBase* backing_store, uint32_t entry,
-                   Object* value) = 0;
+  virtual void Set(Handle<JSObject> holder, uint32_t entry, Object* value) = 0;
 
   virtual void Reconfigure(Handle<JSObject> object,
                            Handle<FixedArrayBase> backing_store, uint32_t entry,
                            Handle<Object> value,
                            PropertyAttributes attributes) = 0;
 
   virtual void Add(Handle<JSObject> object, uint32_t index,
                    Handle<Object> value, PropertyAttributes attributes,
                    uint32_t new_capacity) = 0;
 
@@ skipping 19 matching lines @@
 
   virtual Handle<Object> Pop(Handle<JSArray> receiver,
                              Handle<FixedArrayBase> backing_store) = 0;
 
   virtual Handle<Object> Shift(Handle<JSArray> receiver,
                                Handle<FixedArrayBase> backing_store) = 0;
 
  protected:
   friend class LookupIterator;
 
-  static ElementsAccessor* ForArray(FixedArrayBase* array);
-
-
   // Element handlers distinguish between entries and indices when they
   // manipulate elements. Entries refer to elements in terms of their location
   // in the underlying storage's backing store representation, and are between 0
   // and GetCapacity. Indices refer to elements in terms of the value that would
   // be specified in JavaScript to access the element. In most implementations,
   // indices are equivalent to entries. In the NumberDictionary
   // ElementsAccessor, entries are mapped to an index using the KeyAt method on
   // the NumberDictionary.
   virtual uint32_t GetEntryForIndex(JSObject* holder,
                                     FixedArrayBase* backing_store,
                                     uint32_t index) = 0;
-  virtual PropertyDetails GetDetails(FixedArrayBase* backing_store,
-                                     uint32_t entry) = 0;
+
+  // NOTE: this method violates the handlified function signature convention:
+  // raw pointer parameter |source_holder| in the function that allocates.
+  // This is done intentionally to avoid ArrayConcat() builtin performance
+  // degradation.
+  virtual void CopyElements(JSObject* source_holder, uint32_t source_start,
+                            ElementsKind source_kind,
+                            Handle<FixedArrayBase> destination,
+                            uint32_t destination_start, int copy_size) = 0;
 
  private:
   virtual uint32_t GetCapacity(JSObject* holder,
                                FixedArrayBase* backing_store) = 0;
   static ElementsAccessor** elements_accessors_;
   const char* name_;
 
   DISALLOW_COPY_AND_ASSIGN(ElementsAccessor);
 };
 
 void CheckArrayAbuse(Handle<JSObject> obj, const char* op, uint32_t index,
                      bool allow_appending = false);
 
 MUST_USE_RESULT MaybeHandle<Object> ArrayConstructInitializeElements(
     Handle<JSArray> array,
     Arguments* args);
 
 }  // namespace internal
 }  // namespace v8
 
 #endif  // V8_ELEMENTS_H_