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+// 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.
+// * Neither the name of Google Inc. nor the names of its
+// contributors may be used to endorse or promote products derived
+// from this software without specific prior written permission.
+//
+// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
+// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
+// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
+// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
+// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
+// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
+// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
+// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
+// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
+// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
+// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
+
+#include "v8.h"
+
+#include "objects.h"
+#include "transitions-inl.h"
+#include "utils.h"
+
+namespace v8 {
+namespace internal {
+
+
+MaybeObject* TransitionArray::Allocate(int number_of_transitions) {
+ Heap* heap = Isolate::Current()->heap();
+ // Use FixedArray to not use DescriptorArray::cast on incomplete object.
+ FixedArray* array;
+ MaybeObject* maybe_array =
+ heap->AllocateFixedArray(ToKeyIndex(number_of_transitions));
+ if (!maybe_array->To(&array)) return maybe_array;
+
+ array->set(kElementsTransitionIndex, Smi::FromInt(0));
+ array->set(kPrototypeTransitionsIndex, Smi::FromInt(0));
+ return array;
+}
+
+
+void TransitionArray::CopyFrom(TransitionArray* origin,
+ int origin_transition,
+ int target_transition,
+ const WhitenessWitness& witness) {
+ Set(target_transition,
+ origin->GetKey(origin_transition),
+ origin->GetTarget(origin_transition),
+ witness);
+}
+
+
+static bool InsertionPointFound(String* key1, String* key2) {
+ return key1->Hash() > key2->Hash();
+}
+
+
+MaybeObject* TransitionArray::NewWith(String* name, Map* target) {
+ TransitionArray* result;
+
+ MaybeObject* maybe_array = TransitionArray::Allocate(1);
+ if (!maybe_array->To(&result)) return maybe_array;
+
+ FixedArray::WhitenessWitness witness(result);
+
+ result->Set(0, name, target, witness);
+ return result;
+}
+
+
+MaybeObject* TransitionArray::CopyInsert(String* name, Map* target) {
+ TransitionArray* result;
+
+ int number_of_transitions = this->number_of_transitions();
+ int new_size = number_of_transitions;
+
+ int insertion_index = this->Search(name);
+ if (insertion_index == kNotFound) ++new_size;
+
+ MaybeObject* maybe_array;
+ maybe_array = TransitionArray::Allocate(new_size);
+ if (!maybe_array->To(&result)) return maybe_array;
+
+ if (HasElementsTransition()) {
+ result->set_elements_transition(elements_transition());
+ }
+
+ if (HasPrototypeTransitions()) {
+ result->SetPrototypeTransitions(GetPrototypeTransitions());
+ }
+
+ FixedArray::WhitenessWitness witness(result);
+
+ if (insertion_index != kNotFound) {
+ for (int i = 0; i < number_of_transitions; ++i) {
+ if (i != insertion_index) result->CopyFrom(this, i, i, witness);
+ }
+ result->Set(insertion_index, name, target, witness);
+ return result;
+ }
+
+ insertion_index = 0;
+ for (; insertion_index < number_of_transitions; ++insertion_index) {
+ if (InsertionPointFound(GetKey(insertion_index), name)) break;
+ result->CopyFrom(this, insertion_index, insertion_index, witness);
+ }
+
+ result->Set(insertion_index, name, target, witness);
+
+ for (; insertion_index < number_of_transitions; ++insertion_index) {
+ result->CopyFrom(this, insertion_index, insertion_index + 1, witness);
+ }
+
+ return result;
+}
+
+
+} } // namespace v8::internal