Recfactor core HasElement functionality into ElementsAccessors

src/elements.cc

-// Copyright 2011 the V8 project authors. All rights reserved.
+// 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
 //       with the distribution.
@@ skipping 154 matching lines @@
     }
 #endif
     BackingStoreClass* backing_store = BackingStoreClass::cast(from);
     uint32_t len1 = ElementsAccessorSubclass::GetCapacityImpl(backing_store);
 
     // Optimize if 'other' is empty.
     // We cannot optimize if 'this' is empty, as other may have holes.
     if (len1 == 0) return to;
 
     // Compute how many elements are not in other.
-    int extra = 0;
+    uint32_t extra = 0;
     for (uint32_t y = 0; y < len1; y++) {
-      if (ElementsAccessorSubclass::HasElementAtIndexImpl(
-          backing_store, y, holder, receiver)) {
-        uint32_t key =
-            ElementsAccessorSubclass::GetKeyForIndexImpl(backing_store, y);
+      uint32_t key =
+          ElementsAccessorSubclass::GetKeyForIndexImpl(backing_store, y);
+      if (ElementsAccessorSubclass::HasElementImpl(
+              backing_store, key, holder, receiver)) {
         MaybeObject* maybe_value =
             ElementsAccessorSubclass::GetImpl(backing_store, key,
                                               holder, receiver);
         Object* value;
         if (!maybe_value->ToObject(&value)) return maybe_value;
         ASSERT(!value->IsTheHole());
         if (!HasKey(to, value)) {
           extra++;
         }
       }
@@ skipping 11 matching lines @@
     {
       AssertNoAllocation no_gc;
       WriteBarrierMode mode = result->GetWriteBarrierMode(no_gc);
       for (int i = 0; i < len0; i++) {
         Object* e = to->get(i);
         ASSERT(e->IsString() || e->IsNumber());
         result->set(i, e, mode);
       }
     }
     // Fill in the extra values.
-    int index = 0;
+    uint32_t index = 0;
     for (uint32_t y = 0; y < len1; y++) {
-      if (ElementsAccessorSubclass::HasElementAtIndexImpl(
-          backing_store, y, holder, receiver)) {
-        uint32_t key =
-            ElementsAccessorSubclass::GetKeyForIndexImpl(backing_store, y);
+      uint32_t key =
+          ElementsAccessorSubclass::GetKeyForIndexImpl(backing_store, y);
+      if (ElementsAccessorSubclass::HasElementImpl(
+          backing_store, key, holder, receiver)) {
         MaybeObject* maybe_value =
             ElementsAccessorSubclass::GetImpl(backing_store, key,
                                               holder, receiver);
         Object* value;
         if (!maybe_value->ToObject(&value)) return maybe_value;
         if (!value->IsTheHole() && !HasKey(to, value)) {
           result->set(len0 + index, value);
           index++;
         }
       }
     }
     ASSERT(extra == index);
     return result;
   }
 
  protected:
   static uint32_t GetCapacityImpl(BackingStoreClass* backing_store) {
     return backing_store->length();
   }
 
   virtual uint32_t GetCapacity(FixedArrayBase* backing_store) {
     return ElementsAccessorSubclass::GetCapacityImpl(
         BackingStoreClass::cast(backing_store));
   }
 
-  static bool HasElementAtIndexImpl(BackingStoreClass* backing_store,
-                                    uint32_t index,
-                                    JSObject* holder,
-                                    Object* receiver) {
-    uint32_t key =
-        ElementsAccessorSubclass::GetKeyForIndexImpl(backing_store, index);
+  static bool HasElementImpl(BackingStoreClass* backing_store,
+                             uint32_t key,
+                             JSObject* holder,
+                             Object* receiver) {
     MaybeObject* element =
         ElementsAccessorSubclass::GetImpl(backing_store, key, holder, receiver);
     return !element->IsTheHole();
   }
 
-  virtual bool HasElementAtIndex(FixedArrayBase* backing_store,
-                                 uint32_t index,
-                                 JSObject* holder,
-                                 Object* receiver) {
-    return ElementsAccessorSubclass::HasElementAtIndexImpl(
-        BackingStoreClass::cast(backing_store), index, holder, receiver);
+  virtual bool HasElement(FixedArrayBase* backing_store,
+                          uint32_t key,
+                          JSObject* holder,
+                          Object* receiver) {
+    return ElementsAccessorSubclass::HasElementImpl(
+        BackingStoreClass::cast(backing_store), key, holder, receiver);
   }
 
   static uint32_t GetKeyForIndexImpl(BackingStoreClass* backing_store,
                                      uint32_t index) {
     return index;
   }
 
   virtual uint32_t GetKeyForIndex(FixedArrayBase* backing_store,
-                                              uint32_t index) {
+                                  uint32_t index) {
     return ElementsAccessorSubclass::GetKeyForIndexImpl(
         BackingStoreClass::cast(backing_store), index);
   }
 
  private:
   DISALLOW_COPY_AND_ASSIGN(ElementsAccessorBase);
 };
 
 
 // Super class for all fast element arrays.
@@ skipping 154 matching lines @@
                               JSReceiver::DeleteMode mode) {
     int length = obj->IsJSArray()
         ? Smi::cast(JSArray::cast(obj)->length())->value()
         : FixedDoubleArray::cast(obj->elements())->length();
     if (key < static_cast<uint32_t>(length)) {
       FixedDoubleArray::cast(obj->elements())->set_the_hole(key);
     }
     return obj->GetHeap()->true_value();
   }
 
-  static bool HasElementAtIndexImpl(FixedDoubleArray* backing_store,
-                                    uint32_t index,
-                                    JSObject* holder,
-                                    Object* receiver) {
-    return !backing_store->is_the_hole(index);
+  static bool HasElementImpl(FixedDoubleArray* backing_store,
+                             uint32_t key,
+                             JSObject* holder,
+                             Object* receiver) {
+    return !backing_store->is_the_hole(key);
   }
 };
 
 
 // Super class for all external element arrays.
 template<typename ExternalElementsAccessorSubclass,
          typename ExternalArray>
 class ExternalElementsAccessor
     : public ElementsAccessorBase<ExternalElementsAccessorSubclass,
                                   ExternalArray> {
@@ skipping 18 matching lines @@
     UNREACHABLE();
     return obj;
   }
 
   virtual MaybeObject* Delete(JSObject* obj,
                               uint32_t key,
                               JSReceiver::DeleteMode mode) {
     // External arrays always ignore deletes.
     return obj->GetHeap()->true_value();
   }
+
+  static bool HasElementImpl(ExternalArray* backing_store,
+                             uint32_t key,
+                             JSObject* holder,
+                             Object* receiver) {
+    uint32_t capacity =
+        ExternalElementsAccessorSubclass::GetCapacityImpl(backing_store);
+    return key < capacity;
+  }
 };
 
 
 class ExternalByteElementsAccessor
     : public ExternalElementsAccessor<ExternalByteElementsAccessor,
                                       ExternalByteArray> {
 };
 
 
 class ExternalUnsignedByteElementsAccessor
@@ skipping 173 matching lines @@
                                            element,
                                            key,
                                            obj);
       } else {
         return element;
       }
     }
     return obj->GetHeap()->the_hole_value();
   }
 
+  static bool HasElementImpl(SeededNumberDictionary* backing_store,
+                             uint32_t key,
+                             JSObject* holder,
+                             Object* receiver) {
+    return backing_store->FindEntry(key) !=
+        SeededNumberDictionary::kNotFound;
+  }
+
   static uint32_t GetKeyForIndexImpl(SeededNumberDictionary* dict,
                                      uint32_t index) {
     Object* key = dict->KeyAt(index);
     return Smi::cast(key)->value();
   }
 };
 
 
 class NonStrictArgumentsElementsAccessor
     : public ElementsAccessorBase<NonStrictArgumentsElementsAccessor,
                                   FixedArray> {
  protected:
   friend class ElementsAccessorBase<NonStrictArgumentsElementsAccessor,
                                     FixedArray>;
 
   static MaybeObject* GetImpl(FixedArray* parameter_map,
                               uint32_t key,
                               JSObject* obj,
                               Object* receiver) {
-    Object* probe = GetParameterMapArg(parameter_map, key);
+    Object* probe = GetParameterMapArg(obj, parameter_map, key);
     if (!probe->IsTheHole()) {
       Context* context = Context::cast(parameter_map->get(0));
       int context_index = Smi::cast(probe)->value();
       ASSERT(!context->get(context_index)->IsTheHole());
       return context->get(context_index);
     } else {
       // Object is not mapped, defer to the arguments.
       FixedArray* arguments = FixedArray::cast(parameter_map->get(1));
       MaybeObject* maybe_result = ElementsAccessor::ForArray(arguments)->Get(
           arguments, key, obj, receiver);
@@ skipping 18 matching lines @@
     // TODO(mstarzinger): This was never implemented but will be used once we
     // correctly implement [[DefineOwnProperty]] on arrays.
     UNIMPLEMENTED();
     return obj;
   }
 
   virtual MaybeObject* Delete(JSObject* obj,
                               uint32_t key,
                               JSReceiver::DeleteMode mode) {
     FixedArray* parameter_map = FixedArray::cast(obj->elements());
-    Object* probe = GetParameterMapArg(parameter_map, key);
+    Object* probe = GetParameterMapArg(obj, parameter_map, key);
     if (!probe->IsTheHole()) {
       // TODO(kmillikin): We could check if this was the last aliased
       // parameter, and revert to normal elements in that case.  That
       // would enable GC of the context.
       parameter_map->set_the_hole(key + 2);
     } else {
       FixedArray* arguments = FixedArray::cast(parameter_map->get(1));
       if (arguments->IsDictionary()) {
         return DictionaryElementsAccessor::DeleteCommon(obj, key, mode);
       } else {
         return FastObjectElementsAccessor::DeleteCommon(obj, key);
       }
     }
     return obj->GetHeap()->true_value();
   }
 
   static uint32_t GetCapacityImpl(FixedArray* parameter_map) {
     FixedArrayBase* arguments = FixedArrayBase::cast(parameter_map->get(1));
     return Max(static_cast<uint32_t>(parameter_map->length() - 2),
                ForArray(arguments)->GetCapacity(arguments));
   }
 
   static uint32_t GetKeyForIndexImpl(FixedArray* dict,
                                      uint32_t index) {
     return index;
   }
 
-  static bool HasElementAtIndexImpl(FixedArray* parameter_map,
-                                    uint32_t index,
-                                    JSObject* holder,
-                                    Object* receiver) {
-    Object* probe = GetParameterMapArg(parameter_map, index);
+  static bool HasElementImpl(FixedArray* parameter_map,
+                             uint32_t key,
+                             JSObject* holder,
+                             Object* receiver) {
+    Object* probe = GetParameterMapArg(holder, parameter_map, key);
     if (!probe->IsTheHole()) {
       return true;
     } else {
       FixedArrayBase* arguments = FixedArrayBase::cast(parameter_map->get(1));
       ElementsAccessor* accessor = ElementsAccessor::ForArray(arguments);
-      return !accessor->Get(arguments, index, holder, receiver)->IsTheHole();
+      return !accessor->Get(arguments, key, holder, receiver)->IsTheHole();
     }
   }
 
  private:
-  static Object* GetParameterMapArg(FixedArray* parameter_map,
+  static Object* GetParameterMapArg(JSObject* holder,
+                                    FixedArray* parameter_map,
                                     uint32_t key) {
-    uint32_t length = parameter_map->length();
+    uint32_t length = holder->IsJSArray()
+        ? Smi::cast(JSArray::cast(holder)->length())->value()
+        : parameter_map->length();
     return key < (length - 2 )
         ? parameter_map->get(key + 2)
         : parameter_map->GetHeap()->the_hole_value();
   }
 };
 
 
 ElementsAccessor* ElementsAccessor::ForArray(FixedArrayBase* array) {
   switch (array->map()->instance_type()) {
     case FIXED_ARRAY_TYPE:
@@ skipping 128 matching lines @@
   if (!maybe_obj->To(&new_backing_store)) return maybe_obj;
   new_backing_store->set(0, length);
   { MaybeObject* result = array->SetContent(new_backing_store);
     if (result->IsFailure()) return result;
   }
   return array;
 }
 
 
 } }  // namespace v8::internal