TransitionArray now uses <is_data_property, name, attributes> tuple as a key, which allows to have …

src/objects-inl.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.
 //
 // Review notes:
 //
 // - The use of macros in these inline functions may seem superfluous
 // but it is absolutely needed to make sure gcc generates optimal
 // code. gcc is not happy when attempting to inline too deep.
 //
@@ skipping 1866 matching lines @@
   DCHECK(!ExpectedTransitionKey(map).is_null());
   return Handle<Map>(map->transitions()->GetTarget(
       TransitionArray::kSimpleTransitionIndex));
 }
 
 
 Handle<Map> Map::FindTransitionToField(Handle<Map> map, Handle<Name> key) {
   DisallowHeapAllocation no_allocation;
   if (!map->HasTransitionArray()) return Handle<Map>::null();
   TransitionArray* transitions = map->transitions();
-  int transition = transitions->Search(*key);
+  int transition = transitions->Search(FIELD, *key, NONE);
   if (transition == TransitionArray::kNotFound) return Handle<Map>::null();
-  PropertyDetails target_details = transitions->GetTargetDetails(transition);
-  if (target_details.type() != FIELD) return Handle<Map>::null();
-  if (target_details.attributes() != NONE) return Handle<Map>::null();
+  DCHECK_EQ(FIELD, transitions->GetTargetDetails(transition).type());
+  DCHECK_EQ(NONE, transitions->GetTargetDetails(transition).attributes());
   return Handle<Map>(transitions->GetTarget(transition));
 }
 
 
 ACCESSORS(Oddball, to_string, String, kToStringOffset)
 ACCESSORS(Oddball, to_number, Object, kToNumberOffset)
 
 
 byte Oddball::kind() const {
   return Smi::cast(READ_FIELD(this, kKindOffset))->value();
@@ skipping 1034 matching lines @@
 void Map::LookupDescriptor(JSObject* holder,
                            Name* name,
                            LookupResult* result) {
   DescriptorArray* descriptors = this->instance_descriptors();
   int number = descriptors->SearchWithCache(name, this);
   if (number == DescriptorArray::kNotFound) return result->NotFound();
   result->DescriptorResult(holder, descriptors->GetDetails(number), number);
 }
 
 
-void Map::LookupTransition(JSObject* holder,
-                           Name* name,
+void Map::LookupTransition(JSObject* holder, Name* name,
+                           PropertyAttributes attributes,
                            LookupResult* result) {
-  int transition_index = this->SearchTransition(name);
+  int transition_index = this->SearchTransition(FIELD, name, attributes);
   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()) {
     DCHECK(!GetHeap()->InNewSpace(GetHeap()->empty_fixed_array()));
     return GetHeap()->empty_fixed_array();
@@ skipping 2250 matching lines @@
 }
 
 
 bool Map::HasTransitionArray() const {
   Object* object = READ_FIELD(this, kTransitionsOrBackPointerOffset);
   return object->IsTransitionArray();
 }
 
 
 Map* Map::elements_transition_map() {
-  int index = transitions()->Search(GetHeap()->elements_transition_symbol());
+  int index =
+      transitions()->SearchSpecial(GetHeap()->elements_transition_symbol());
   return transitions()->GetTarget(index);
 }
 
 
 bool Map::CanHaveMoreTransitions() {
   if (!HasTransitionArray()) return true;
   return transitions()->number_of_transitions() <
          TransitionArray::kMaxNumberOfTransitions;
 }
 
 
 Map* Map::GetTransition(int transition_index) {
   return transitions()->GetTarget(transition_index);
 }
 
 
-int Map::SearchTransition(Name* name) {
-  if (HasTransitionArray()) return transitions()->Search(name);
+int Map::SearchSpecialTransition(Symbol* name) {
+  if (HasTransitionArray()) {
+    return transitions()->SearchSpecial(name);
+  }
   return TransitionArray::kNotFound;
 }
 
+
+int Map::SearchTransition(PropertyType type, Name* name,
+                          PropertyAttributes attributes) {
+  if (HasTransitionArray()) {
+    return transitions()->Search(type, name, attributes);
+  }
+  return TransitionArray::kNotFound;
+}
+
 
 FixedArray* Map::GetPrototypeTransitions() {
   if (!HasTransitionArray()) return GetHeap()->empty_fixed_array();
   if (!transitions()->HasPrototypeTransitions()) {
     return GetHeap()->empty_fixed_array();
   }
   return transitions()->GetPrototypeTransitions();
 }
 
 
@@ skipping 29 matching lines @@
   // Transition arrays are not shared. When one is replaced, it should not
   // keep referenced objects alive, so we zap it.
   // When there is another reference to the array somewhere (e.g. a handle),
   // not zapping turns from a waste of memory into a source of crashes.
   if (HasTransitionArray()) {
 #ifdef DEBUG
     for (int i = 0; i < transitions()->number_of_transitions(); i++) {
       Map* target = transitions()->GetTarget(i);
       if (target->instance_descriptors() == instance_descriptors()) {
         Name* key = transitions()->GetKey(i);
-        int new_target_index = transition_array->Search(key);
-        DCHECK(new_target_index != TransitionArray::kNotFound);
-        DCHECK(transition_array->GetTarget(new_target_index) == target);
+        int new_target_index;
+        if (TransitionArray::IsSpecialTransition(key)) {
+          new_target_index = transition_array->SearchSpecial(Symbol::cast(key));
+        } else {
+          PropertyDetails details =
+              TransitionArray::GetTargetDetails(key, target);
+          new_target_index = transition_array->Search(details.type(), key,
+                                                      details.attributes());
+        }
+        DCHECK_NE(TransitionArray::kNotFound, new_target_index);
+        DCHECK_EQ(target, transition_array->GetTarget(new_target_index));
       }
     }
 #endif
     DCHECK(transitions() != transition_array);
     ZapTransitions();
   }
 
   WRITE_FIELD(this, kTransitionsOrBackPointerOffset, transition_array);
   CONDITIONAL_WRITE_BARRIER(
       GetHeap(), this, kTransitionsOrBackPointerOffset, transition_array, mode);
@@ skipping 2012 matching lines @@
 #undef READ_SHORT_FIELD
 #undef WRITE_SHORT_FIELD
 #undef READ_BYTE_FIELD
 #undef WRITE_BYTE_FIELD
 #undef NOBARRIER_READ_BYTE_FIELD
 #undef NOBARRIER_WRITE_BYTE_FIELD
 
 } }  // namespace v8::internal
 
 #endif  // V8_OBJECTS_INL_H_