| // 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. |
| |
| #include "src/v8.h" |
| |
| #include "src/objects.h" |
| #include "src/transitions-inl.h" |
| #include "src/utils.h" |
| |
| namespace v8 { |
| namespace internal { |
| |
| |
| Handle<TransitionArray> TransitionArray::Allocate(Isolate* isolate, |
| int number_of_transitions) { |
| Handle<FixedArray> array = |
| isolate->factory()->NewFixedArray(ToKeyIndex(number_of_transitions)); |
| array->set(kPrototypeTransitionsIndex, Smi::FromInt(0)); |
| return Handle<TransitionArray>::cast(array); |
| } |
| |
| |
| Handle<TransitionArray> TransitionArray::AllocateSimple(Isolate* isolate, |
| Handle<Map> target) { |
| Handle<FixedArray> array = |
| isolate->factory()->NewFixedArray(kSimpleTransitionSize); |
| array->set(kSimpleTransitionTarget, *target); |
| return Handle<TransitionArray>::cast(array); |
| } |
| |
| |
| void TransitionArray::NoIncrementalWriteBarrierCopyFrom(TransitionArray* origin, |
| int origin_transition, |
| int target_transition) { |
| NoIncrementalWriteBarrierSet(target_transition, |
| origin->GetKey(origin_transition), |
| origin->GetTarget(origin_transition)); |
| } |
| |
| |
| static bool InsertionPointFound(Name* key1, Name* key2) { |
| return key1->Hash() > key2->Hash(); |
| } |
| |
| |
| Handle<TransitionArray> TransitionArray::NewWith(Handle<Map> map, |
| Handle<Name> name, |
| Handle<Map> target, |
| SimpleTransitionFlag flag) { |
| Handle<TransitionArray> result; |
| Isolate* isolate = name->GetIsolate(); |
| |
| if (flag == SIMPLE_TRANSITION) { |
| result = AllocateSimple(isolate, target); |
| } else { |
| result = Allocate(isolate, 1); |
| result->NoIncrementalWriteBarrierSet(0, *name, *target); |
| } |
| result->set_back_pointer_storage(map->GetBackPointer()); |
| return result; |
| } |
| |
| |
| Handle<TransitionArray> TransitionArray::ExtendToFullTransitionArray( |
| Handle<Map> containing_map) { |
| ASSERT(!containing_map->transitions()->IsFullTransitionArray()); |
| int nof = containing_map->transitions()->number_of_transitions(); |
| |
| // A transition array may shrink during GC. |
| Handle<TransitionArray> result = Allocate(containing_map->GetIsolate(), nof); |
| DisallowHeapAllocation no_gc; |
| int new_nof = containing_map->transitions()->number_of_transitions(); |
| if (new_nof != nof) { |
| ASSERT(new_nof == 0); |
| result->Shrink(ToKeyIndex(0)); |
| } else if (nof == 1) { |
| result->NoIncrementalWriteBarrierCopyFrom( |
| containing_map->transitions(), kSimpleTransitionIndex, 0); |
| } |
| |
| result->set_back_pointer_storage( |
| containing_map->transitions()->back_pointer_storage()); |
| return result; |
| } |
| |
| |
| Handle<TransitionArray> TransitionArray::CopyInsert(Handle<Map> map, |
| Handle<Name> name, |
| Handle<Map> target, |
| SimpleTransitionFlag flag) { |
| if (!map->HasTransitionArray()) { |
| return TransitionArray::NewWith(map, name, target, flag); |
| } |
| |
| int number_of_transitions = map->transitions()->number_of_transitions(); |
| int new_size = number_of_transitions; |
| |
| int insertion_index = map->transitions()->Search(*name); |
| if (insertion_index == kNotFound) ++new_size; |
| |
| Handle<TransitionArray> result = Allocate(map->GetIsolate(), new_size); |
| |
| // The map's transition array may grown smaller during the allocation above as |
| // it was weakly traversed, though it is guaranteed not to disappear. Trim the |
| // result copy if needed, and recompute variables. |
| ASSERT(map->HasTransitionArray()); |
| DisallowHeapAllocation no_gc; |
| TransitionArray* array = map->transitions(); |
| if (array->number_of_transitions() != number_of_transitions) { |
| ASSERT(array->number_of_transitions() < number_of_transitions); |
| |
| number_of_transitions = array->number_of_transitions(); |
| new_size = number_of_transitions; |
| |
| insertion_index = array->Search(*name); |
| if (insertion_index == kNotFound) ++new_size; |
| |
| result->Shrink(ToKeyIndex(new_size)); |
| } |
| |
| if (array->HasPrototypeTransitions()) { |
| result->SetPrototypeTransitions(array->GetPrototypeTransitions()); |
| } |
| |
| if (insertion_index != kNotFound) { |
| for (int i = 0; i < number_of_transitions; ++i) { |
| if (i != insertion_index) { |
| result->NoIncrementalWriteBarrierCopyFrom(array, i, i); |
| } |
| } |
| result->NoIncrementalWriteBarrierSet(insertion_index, *name, *target); |
| result->set_back_pointer_storage(array->back_pointer_storage()); |
| return result; |
| } |
| |
| insertion_index = 0; |
| for (; insertion_index < number_of_transitions; ++insertion_index) { |
| if (InsertionPointFound(array->GetKey(insertion_index), *name)) break; |
| result->NoIncrementalWriteBarrierCopyFrom( |
| array, insertion_index, insertion_index); |
| } |
| |
| result->NoIncrementalWriteBarrierSet(insertion_index, *name, *target); |
| |
| for (; insertion_index < number_of_transitions; ++insertion_index) { |
| result->NoIncrementalWriteBarrierCopyFrom( |
| array, insertion_index, insertion_index + 1); |
| } |
| |
| result->set_back_pointer_storage(array->back_pointer_storage()); |
| return result; |
| } |
| |
| |
| } } // namespace v8::internal |