| /** |
| * Licensed to the Apache Software Foundation (ASF) under one |
| * or more contributor license agreements. See the NOTICE file |
| * distributed with this work for additional information |
| * regarding copyright ownership. The ASF licenses this file |
| * to you under the Apache License, Version 2.0 (the |
| * "License"); you may not use this file except in compliance |
| * with the License. You may obtain a copy of the License at |
| * |
| * http://www.apache.org/licenses/LICENSE-2.0 |
| * |
| * Unless required by applicable law or agreed to in writing, |
| * software distributed under the License is distributed on an |
| * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY |
| * KIND, either express or implied. See the License for the |
| * specific language governing permissions and limitations |
| * under the License. |
| */ |
| #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*); |
| void append(DoublyLinkedList<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; |
| } |
| |
| template<typename T> inline void DoublyLinkedList<T>::append(DoublyLinkedList<T>& other) |
| { |
| if (!other.head()) |
| return; |
| |
| if (!head()) { |
| m_head = other.head(); |
| m_tail = other.tail(); |
| other.clear(); |
| return; |
| } |
| |
| ASSERT(tail()); |
| ASSERT(other.head()); |
| T* otherHead = other.head(); |
| T* otherTail = other.tail(); |
| other.clear(); |
| |
| ASSERT(!m_tail->next()); |
| m_tail->setNext(otherHead); |
| ASSERT(!otherHead->prev()); |
| otherHead->setPrev(m_tail); |
| m_tail = otherTail; |
| } |
| |
| } // namespace WTF |
| |
| using WTF::DoublyLinkedListNode; |
| using WTF::DoublyLinkedList; |
| |
| #endif |