| /* |
| * Copyright (C) 2014 Google Inc. 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. |
| */ |
| |
| #ifndef THIRD_PARTY_BLINK_RENDERER_PLATFORM_HEAP_HEAP_LINKED_STACK_H_ |
| #define THIRD_PARTY_BLINK_RENDERER_PLATFORM_HEAP_HEAP_LINKED_STACK_H_ |
| |
| #include "third_party/blink/renderer/platform/heap/heap.h" |
| #include "third_party/blink/renderer/platform/heap/visitor.h" |
| #include "third_party/blink/renderer/platform/wtf/allocator.h" |
| |
| namespace blink { |
| |
| // HeapLinkedStack<> is an Oilpan-managed stack that avoids pre-allocation |
| // of memory and heap fragmentation. |
| // |
| // The API was originally implemented on the call stack by LinkedStack<> |
| // (now removed: https://codereview.chromium.org/2761853003/). |
| // See https://codereview.chromium.org/17314010 for the original use-case. |
| template <typename T> |
| class HeapLinkedStack : public GarbageCollected<HeapLinkedStack<T>> { |
| public: |
| HeapLinkedStack() : size_(0) {} |
| |
| bool IsEmpty(); |
| |
| void Push(const T&); |
| const T& Peek(); |
| void Pop(); |
| |
| size_t size(); |
| |
| void Trace(blink::Visitor* visitor) { |
| for (Node* current = head_; current; current = current->next_) |
| visitor->Trace(current); |
| } |
| |
| private: |
| class Node : public GarbageCollected<Node> { |
| public: |
| Node(const T&, Node* next); |
| |
| void Trace(blink::Visitor* visitor) { visitor->Trace(data_); } |
| |
| T data_; |
| Member<Node> next_; |
| }; |
| |
| Member<Node> head_; |
| size_t size_; |
| }; |
| |
| template <typename T> |
| HeapLinkedStack<T>::Node::Node(const T& data, Node* next) |
| : data_(data), next_(next) {} |
| |
| template <typename T> |
| inline bool HeapLinkedStack<T>::IsEmpty() { |
| return !head_; |
| } |
| |
| template <typename T> |
| inline void HeapLinkedStack<T>::Push(const T& data) { |
| head_ = MakeGarbageCollected<Node>(data, head_); |
| ++size_; |
| } |
| |
| template <typename T> |
| inline const T& HeapLinkedStack<T>::Peek() { |
| return head_->data_; |
| } |
| |
| template <typename T> |
| inline void HeapLinkedStack<T>::Pop() { |
| DCHECK(head_); |
| DCHECK(size_); |
| head_ = head_->next_; |
| --size_; |
| } |
| |
| template <typename T> |
| inline size_t HeapLinkedStack<T>::size() { |
| return size_; |
| } |
| |
| } // namespace blink |
| |
| #endif // THIRD_PARTY_BLINK_RENDERER_PLATFORM_HEAP_HEAP_LINKED_STACK_H_ |