Handlefy Descriptor and other code in objects.cc

src/objects-inl.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 1710 matching lines @@
       if (double_array->is_the_hole(i)) {
         TransitionElementsKind(object, FAST_HOLEY_DOUBLE_ELEMENTS);
         return;
       }
     }
     TransitionElementsKind(object, FAST_DOUBLE_ELEMENTS);
   }
 }
 
 
-MaybeObject* JSObject::GetElementsTransitionMap(Isolate* isolate,
-                                                ElementsKind to_kind) {
-  Map* current_map = map();
-  ElementsKind from_kind = current_map->elements_kind();
-  if (from_kind == to_kind) return current_map;
-
-  Context* native_context = isolate->context()->native_context();
-  Object* maybe_array_maps = native_context->js_array_maps();
-  if (maybe_array_maps->IsFixedArray()) {
-    FixedArray* array_maps = FixedArray::cast(maybe_array_maps);
-    if (array_maps->get(from_kind) == current_map) {
-      Object* maybe_transitioned_map = array_maps->get(to_kind);
-      if (maybe_transitioned_map->IsMap()) {
-        return Map::cast(maybe_transitioned_map);
-      }
-    }
-  }
-
-  return GetElementsTransitionMapSlow(to_kind);
-}
-
-
 void JSObject::SetMapAndElements(Handle<JSObject> object,
                                  Handle<Map> new_map,
                                  Handle<FixedArrayBase> value) {
   JSObject::MigrateToMap(object, new_map);
   ASSERT((object->map()->has_fast_smi_or_object_elements() ||
           (*value == object->GetHeap()->empty_fixed_array())) ==
          (value->map() == object->GetHeap()->fixed_array_map() ||
           value->map() == object->GetHeap()->fixed_cow_array_map()));
   ASSERT((*value == object->GetHeap()->empty_fixed_array()) ||
          (object->map()->has_fast_double_elements() ==
           value->IsFixedDoubleArray()));
   object->set_elements(*value);
 }
 
 
 void JSObject::set_elements(FixedArrayBase* value, WriteBarrierMode mode) {
   WRITE_FIELD(this, kElementsOffset, value);
   CONDITIONAL_WRITE_BARRIER(GetHeap(), this, kElementsOffset, value, mode);
 }
 
 
 void JSObject::initialize_properties() {
   ASSERT(!GetHeap()->InNewSpace(GetHeap()->empty_fixed_array()));
   WRITE_FIELD(this, kPropertiesOffset, GetHeap()->empty_fixed_array());
 }
 
 
 void JSObject::initialize_elements() {
-  if (map()->has_fast_smi_or_object_elements() ||
-      map()->has_fast_double_elements()) {
-    ASSERT(!GetHeap()->InNewSpace(GetHeap()->empty_fixed_array()));
-    WRITE_FIELD(this, kElementsOffset, GetHeap()->empty_fixed_array());
-  } else if (map()->has_external_array_elements()) {
-    ExternalArray* empty_array = GetHeap()->EmptyExternalArrayForMap(map());
-    ASSERT(!GetHeap()->InNewSpace(empty_array));
-    WRITE_FIELD(this, kElementsOffset, empty_array);
-  } else if (map()->has_fixed_typed_array_elements()) {
-    FixedTypedArrayBase* empty_array =
-      GetHeap()->EmptyFixedTypedArrayForMap(map());
-    ASSERT(!GetHeap()->InNewSpace(empty_array));
-    WRITE_FIELD(this, kElementsOffset, empty_array);
-  } else {
-    UNREACHABLE();
-  }
+  FixedArrayBase* elements = map()->GetInitialElements();
+  WRITE_FIELD(this, kElementsOffset, elements);
 }
 
 
-MaybeObject* JSObject::ResetElements() {
-  if (map()->is_observed()) {
-    // Maintain invariant that observed elements are always in dictionary mode.
-    SeededNumberDictionary* dictionary;
-    MaybeObject* maybe = SeededNumberDictionary::Allocate(GetHeap(), 0);
-    if (!maybe->To(&dictionary)) return maybe;
-    if (map() == GetHeap()->sloppy_arguments_elements_map()) {
-      FixedArray::cast(elements())->set(1, dictionary);
-    } else {
-      set_elements(dictionary);
-    }
-    return this;
-  }
-
-  ElementsKind elements_kind = GetInitialFastElementsKind();
-  if (!FLAG_smi_only_arrays) {
-    elements_kind = FastSmiToObjectElementsKind(elements_kind);
-  }
-  MaybeObject* maybe = GetElementsTransitionMap(GetIsolate(), elements_kind);
-  Map* map;
-  if (!maybe->To(&map)) return maybe;
-  set_map(map);
-  initialize_elements();
-
-  return this;
-}
-
-
 Handle<String> JSObject::ExpectedTransitionKey(Handle<Map> map) {
   DisallowHeapAllocation no_gc;
   if (!map->HasTransitionArray()) return Handle<String>::null();
   TransitionArray* transitions = map->transitions();
   if (!transitions->IsSimpleTransition()) return Handle<String>::null();
   int transition = TransitionArray::kSimpleTransitionIndex;
   PropertyDetails details = transitions->GetTargetDetails(transition);
   Name* name = transitions->GetKey(transition);
   if (details.type() != FIELD) return Handle<String>::null();
   if (details.attributes() != NONE) return Handle<String>::null();
@@ skipping 819 matching lines @@
 
 void Map::LookupTransition(JSObject* holder,
                            Name* name,
                            LookupResult* result) {
   int transition_index = this->SearchTransition(name);
   if (transition_index == TransitionArray::kNotFound) return result->NotFound();
   result->TransitionResult(holder, this->GetTransition(transition_index));
 }
 
 
+FixedArrayBase* Map::GetInitialElements() {
+  if (has_fast_smi_or_object_elements() ||
+      has_fast_double_elements()) {
+    ASSERT(!GetHeap()->InNewSpace(GetHeap()->empty_fixed_array()));
+    return GetHeap()->empty_fixed_array();
+  } else if (has_external_array_elements()) {
+    ExternalArray* empty_array = GetHeap()->EmptyExternalArrayForMap(this);
+    ASSERT(!GetHeap()->InNewSpace(empty_array));
+    return empty_array;
+  } else if (has_fixed_typed_array_elements()) {
+    FixedTypedArrayBase* empty_array =
+      GetHeap()->EmptyFixedTypedArrayForMap(this);
+    ASSERT(!GetHeap()->InNewSpace(empty_array));
+    return empty_array;
+  } else {
+    UNREACHABLE();
+  }
+  return NULL;
+}
+
+
 Object** DescriptorArray::GetKeySlot(int descriptor_number) {
   ASSERT(descriptor_number < number_of_descriptors());
   return RawFieldOfElementAt(ToKeyIndex(descriptor_number));
 }
 
 
 Object** DescriptorArray::GetDescriptorStartSlot(int descriptor_number) {
   return GetKeySlot(descriptor_number);
 }
 
@@ skipping 84 matching lines @@
 
 
 AccessorDescriptor* DescriptorArray::GetCallbacks(int descriptor_number) {
   ASSERT(GetType(descriptor_number) == CALLBACKS);
   Foreign* p = Foreign::cast(GetCallbacksObject(descriptor_number));
   return reinterpret_cast<AccessorDescriptor*>(p->foreign_address());
 }
 
 
 void DescriptorArray::Get(int descriptor_number, Descriptor* desc) {
-  desc->Init(GetKey(descriptor_number),
-             GetValue(descriptor_number),
+  desc->Init(handle(GetKey(descriptor_number), GetIsolate()),
+             handle(GetValue(descriptor_number), GetIsolate()),
              GetDetails(descriptor_number));
 }
 
 
 void DescriptorArray::Set(int descriptor_number,
                           Descriptor* desc,
                           const WhitenessWitness&) {
   // Range check.
   ASSERT(descriptor_number < number_of_descriptors());
 
   NoIncrementalWriteBarrierSet(this,
                                ToKeyIndex(descriptor_number),
-                               desc->GetKey());
+                               *desc->GetKey());
   NoIncrementalWriteBarrierSet(this,
                                ToValueIndex(descriptor_number),
-                               desc->GetValue());
+                               *desc->GetValue());
   NoIncrementalWriteBarrierSet(this,
                                ToDetailsIndex(descriptor_number),
                                desc->GetDetails().AsSmi());
 }
 
 
 void DescriptorArray::Set(int descriptor_number, Descriptor* desc) {
   // Range check.
   ASSERT(descriptor_number < number_of_descriptors());
 
-  set(ToKeyIndex(descriptor_number), desc->GetKey());
-  set(ToValueIndex(descriptor_number), desc->GetValue());
+  set(ToKeyIndex(descriptor_number), *desc->GetKey());
+  set(ToValueIndex(descriptor_number), *desc->GetValue());
   set(ToDetailsIndex(descriptor_number), desc->GetDetails().AsSmi());
 }
 
 
 void DescriptorArray::Append(Descriptor* desc,
                              const WhitenessWitness& witness) {
+  DisallowHeapAllocation no_gc;
   int descriptor_number = number_of_descriptors();
   SetNumberOfDescriptors(descriptor_number + 1);
   Set(descriptor_number, desc, witness);
 
   uint32_t hash = desc->GetKey()->Hash();
 
   int insertion;
 
   for (insertion = descriptor_number; insertion > 0; --insertion) {
     Name* key = GetSortedKey(insertion - 1);
     if (key->Hash() <= hash) break;
     SetSortedKey(insertion, GetSortedKeyIndex(insertion - 1));
   }
 
   SetSortedKey(insertion, descriptor_number);
 }
 
 
 void DescriptorArray::Append(Descriptor* desc) {
+  DisallowHeapAllocation no_gc;
   int descriptor_number = number_of_descriptors();
   SetNumberOfDescriptors(descriptor_number + 1);
   Set(descriptor_number, desc);
 
   uint32_t hash = desc->GetKey()->Hash();
 
   int insertion;
 
   for (insertion = descriptor_number; insertion > 0; --insertion) {
     Name* key = GetSortedKey(insertion - 1);
@@ skipping 2073 matching lines @@
 
 
 bool Map::CanHaveMoreTransitions() {
   if (!HasTransitionArray()) return true;
   return FixedArray::SizeFor(transitions()->length() +
                              TransitionArray::kTransitionSize)
       <= Page::kMaxRegularHeapObjectSize;
 }
 
 
-MaybeObject* Map::AddTransition(Name* key,
-                                Map* target,
-                                SimpleTransitionFlag flag) {
-  if (HasTransitionArray()) return transitions()->CopyInsert(key, target);
-  return TransitionArray::NewWith(flag, key, target, GetBackPointer());
-}
-
-
 void Map::SetTransition(int transition_index, Map* target) {
   transitions()->SetTarget(transition_index, target);
 }
 
 
 Map* Map::GetTransition(int transition_index) {
   return transitions()->GetTarget(transition_index);
 }
 
 
 int Map::SearchTransition(Name* name) {
   if (HasTransitionArray()) return transitions()->Search(name);
   return TransitionArray::kNotFound;
 }
 
 
-MaybeObject* Map::set_elements_transition_map(Map* transitioned_map) {
-  TransitionArray* transitions;
-  MaybeObject* maybe_transitions = AddTransition(
-      GetHeap()->elements_transition_symbol(),
-      transitioned_map,
-      FULL_TRANSITION);
-  if (!maybe_transitions->To(&transitions)) return maybe_transitions;
-  set_transitions(transitions);
-  return transitions;
-}
-
-
 FixedArray* Map::GetPrototypeTransitions() {
   if (!HasTransitionArray()) return GetHeap()->empty_fixed_array();
   if (!transitions()->HasPrototypeTransitions()) {
     return GetHeap()->empty_fixed_array();
   }
   return transitions()->GetPrototypeTransitions();
 }
 
 
 MaybeObject* Map::SetPrototypeTransitions(FixedArray* proto_transitions) {
@@ skipping 1995 matching lines @@
 #undef READ_UINT32_FIELD
 #undef WRITE_UINT32_FIELD
 #undef READ_SHORT_FIELD
 #undef WRITE_SHORT_FIELD
 #undef READ_BYTE_FIELD
 #undef WRITE_BYTE_FIELD
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_INL_H_