1/* 2 * Copyright (C) 2014 Apple Inc. All rights reserved. 3 * 4 * Redistribution and use in source and binary forms, with or without 5 * modification, are permitted provided that the following conditions 6 * are met: 7 * 1. Redistributions of source code must retain the above copyright 8 * notice, this list of conditions and the following disclaimer. 9 * 2. Redistributions in binary form must reproduce the above copyright 10 * notice, this list of conditions and the following disclaimer in the 11 * documentation and/or other materials provided with the distribution. 12 * 13 * THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS'' 14 * AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, 15 * THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR 16 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS 17 * BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR 18 * CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF 19 * SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS 20 * INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN 21 * CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) 22 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF 23 * THE POSSIBILITY OF SUCH DAMAGE. 24 */ 25 26#ifndef OpaqueRootSet_h 27#define OpaqueRootSet_h 28 29#include <wtf/HashSet.h> 30 31namespace JSC { 32 33class OpaqueRootSet { 34 WTF_MAKE_NONCOPYABLE(OpaqueRootSet); 35public: 36 OpaqueRootSet() 37 : m_lastQueriedRoot(nullptr) 38 , m_containsLastQueriedRoot(false) 39 { 40 } 41 42 bool contains(void* root) const 43 { 44 if (root != m_lastQueriedRoot) { 45 m_lastQueriedRoot = root; 46 m_containsLastQueriedRoot = m_roots.contains(root); 47 } 48 return m_containsLastQueriedRoot; 49 } 50 51 bool isEmpty() const 52 { 53 return m_roots.isEmpty(); 54 } 55 56 void clear() 57 { 58 m_roots.clear(); 59 m_lastQueriedRoot = nullptr; 60 m_containsLastQueriedRoot = false; 61 } 62 63 void add(void* root) 64 { 65 if (root == m_lastQueriedRoot) 66 m_containsLastQueriedRoot = true; 67 m_roots.add(root); 68 } 69 70 int size() const 71 { 72 return m_roots.size(); 73 } 74 75 HashSet<void*>::const_iterator begin() const 76 { 77 return m_roots.begin(); 78 } 79 80 HashSet<void*>::const_iterator end() const 81 { 82 return m_roots.end(); 83 } 84 85 86private: 87 HashSet<void*> m_roots; 88 mutable void* m_lastQueriedRoot; 89 mutable bool m_containsLastQueriedRoot; 90}; 91 92} // namespace JSC 93 94#endif // OpaqueRootSet_h 95