JavaScriptCore-903.tar.gz

[apple/javascriptcore.git] / wtf / DoublyLinkedList.h

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+/*
+ * 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 {
+
+template <typename Node> class DoublyLinkedList {
+public:
+    DoublyLinkedList();
+    
+    bool isEmpty();
+
+    Node* head();
+
+    void append(Node*);
+    void remove(Node*);
+
+private:
+    Node* m_head;
+    Node* m_tail;
+};
+
+template <typename Node> inline DoublyLinkedList<Node>::DoublyLinkedList()
+    : m_head(0)
+    , m_tail(0)
+{
+}
+
+template <typename Node> inline bool DoublyLinkedList<Node>::isEmpty()
+{
+    return !m_head;
+}
+
+template <typename Node> inline Node* DoublyLinkedList<Node>::head()
+{
+    return m_head;
+}
+
+template <typename Node> inline void DoublyLinkedList<Node>::append(Node* 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 Node> inline void DoublyLinkedList<Node>::remove(Node* 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();
+    }
+}
+
+} // namespace WTF
+
+using WTF::DoublyLinkedList;
+
+#endif