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