| /* |
| * Copyright (C) 2016 Apple 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: |
| * 1. Redistributions of source code must retain the above copyright |
| * notice, this list of conditions and the following disclaimer. |
| * 2. 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. |
| * |
| * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``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 APPLE INC. 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 List_h |
| #define List_h |
| |
| namespace bmalloc { |
| |
| template<typename T> |
| struct ListNode { |
| ListNode() |
| : prev(this) |
| , next(this) |
| { |
| } |
| |
| ListNode<T>* prev; |
| ListNode<T>* next; |
| }; |
| |
| template<typename T> |
| class List { |
| static_assert(std::is_trivially_destructible<T>::value, "List must have a trivial destructor."); |
| public: |
| bool isEmpty() { return m_root.next == &m_root; } |
| |
| T* head() { return static_cast<T*>(m_root.next); } |
| T* tail() { return static_cast<T*>(m_root.prev); } |
| |
| void push(T* node) |
| { |
| ListNode<T>* it = tail(); |
| insertAfter(it, node); |
| } |
| |
| T* pop() |
| { |
| ListNode<T>* result = tail(); |
| remove(result); |
| return static_cast<T*>(result); |
| } |
| |
| T* popFront() |
| { |
| ListNode<T>* result = head(); |
| remove(result); |
| return static_cast<T*>(result); |
| } |
| |
| void insertAfter(ListNode<T>* it, ListNode<T>* node) |
| { |
| ListNode<T>* prev = it; |
| ListNode<T>* next = it->next; |
| |
| node->next = next; |
| next->prev = node; |
| |
| node->prev = prev; |
| prev->next = node; |
| } |
| |
| void remove(ListNode<T>* node) |
| { |
| ListNode<T>* next = node->next; |
| ListNode<T>* prev = node->prev; |
| |
| next->prev = prev; |
| prev->next = next; |
| |
| node->prev = node; |
| node->next = node; |
| } |
| |
| private: |
| ListNode<T> m_root; |
| }; |
| |
| } // namespace bmalloc |
| |
| #endif // List_h |