| /* |
| * Copyright (C) 2011 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. AND ITS 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 APPLE INC. OR ITS 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 DoublyLinkedList_h |
| #define DoublyLinkedList_h |
| |
| namespace WTF { |
| |
| // This class allows nodes to share code without dictating data member layout. |
| template<typename T> class DoublyLinkedListNode { |
| public: |
| DoublyLinkedListNode(); |
| |
| void setPrev(T*); |
| void setNext(T*); |
| |
| T* prev() const; |
| T* next() const; |
| }; |
| |
| template<typename T> inline DoublyLinkedListNode<T>::DoublyLinkedListNode() |
| { |
| setPrev(0); |
| setNext(0); |
| } |
| |
| template<typename T> inline void DoublyLinkedListNode<T>::setPrev(T* prev) |
| { |
| static_cast<T*>(this)->m_prev = prev; |
| } |
| |
| template<typename T> inline void DoublyLinkedListNode<T>::setNext(T* next) |
| { |
| static_cast<T*>(this)->m_next = next; |
| } |
| |
| template<typename T> inline T* DoublyLinkedListNode<T>::prev() const |
| { |
| return static_cast<const T*>(this)->m_prev; |
| } |
| |
| template<typename T> inline T* DoublyLinkedListNode<T>::next() const |
| { |
| return static_cast<const T*>(this)->m_next; |
| } |
| |
| template<typename T> class DoublyLinkedList { |
| public: |
| DoublyLinkedList(); |
| |
| bool isEmpty() const; |
| size_t size() const; // This is O(n). |
| void clear(); |
| |
| T* head() const; |
| T* removeHead(); |
| |
| T* tail() const; |
| |
| void push(T*); |
| void append(T*); |
| void remove(T*); |
| |
| private: |
| T* m_head; |
| T* m_tail; |
| }; |
| |
| template<typename T> inline DoublyLinkedList<T>::DoublyLinkedList() |
| : m_head(0) |
| , m_tail(0) |
| { |
| } |
| |
| template<typename T> inline bool DoublyLinkedList<T>::isEmpty() const |
| { |
| return !m_head; |
| } |
| |
| template<typename T> inline size_t DoublyLinkedList<T>::size() const |
| { |
| size_t size = 0; |
| for (T* node = m_head; node; node = node->next()) |
| ++size; |
| return size; |
| } |
| |
| template<typename T> inline void DoublyLinkedList<T>::clear() |
| { |
| m_head = 0; |
| m_tail = 0; |
| } |
| |
| template<typename T> inline T* DoublyLinkedList<T>::head() const |
| { |
| return m_head; |
| } |
| |
| template<typename T> inline T* DoublyLinkedList<T>::tail() const |
| { |
| return m_tail; |
| } |
| |
| template<typename T> inline void DoublyLinkedList<T>::push(T* node) |
| { |
| if (!m_head) { |
| ASSERT(!m_tail); |
| m_head = node; |
| m_tail = node; |
| node->setPrev(0); |
| node->setNext(0); |
| return; |
| } |
| |
| ASSERT(m_tail); |
| m_head->setPrev(node); |
| node->setNext(m_head); |
| node->setPrev(0); |
| m_head = node; |
| } |
| |
| template<typename T> inline void DoublyLinkedList<T>::append(T* node) |
| { |
| if (!m_tail) { |
| ASSERT(!m_head); |
| m_head = node; |
| m_tail = node; |
| node->setPrev(0); |
| node->setNext(0); |
| return; |
| } |
| |
| ASSERT(m_head); |
| m_tail->setNext(node); |
| node->setPrev(m_tail); |
| node->setNext(0); |
| m_tail = node; |
| } |
| |
| template<typename T> inline void DoublyLinkedList<T>::remove(T* node) |
| { |
| if (node->prev()) { |
| ASSERT(node != m_head); |
| node->prev()->setNext(node->next()); |
| } else { |
| ASSERT(node == m_head); |
| m_head = node->next(); |
| } |
| |
| if (node->next()) { |
| ASSERT(node != m_tail); |
| node->next()->setPrev(node->prev()); |
| } else { |
| ASSERT(node == m_tail); |
| m_tail = node->prev(); |
| } |
| } |
| |
| template<typename T> inline T* DoublyLinkedList<T>::removeHead() |
| { |
| T* node = head(); |
| if (node) |
| remove(node); |
| return node; |
| } |
| |
| } // namespace WTF |
| |
| using WTF::DoublyLinkedListNode; |
| using WTF::DoublyLinkedList; |
| |
| #endif |