1/*
2 * Copyright (C) 2016-2019 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#pragma once
27
28#include <wtf/HashTable.h>
29#include <wtf/PrintStream.h>
30
31namespace JSC {
32
33class JSCell;
34
35class VisitRaceKey {
36public:
37 VisitRaceKey() { }
38
39 VisitRaceKey(JSCell* cell, const char* raceName)
40 : m_cell(cell)
41 , m_raceName(raceName)
42 {
43 }
44
45 VisitRaceKey(WTF::HashTableDeletedValueType)
46 : m_raceName(m_deletedValueRaceName)
47 {
48 }
49
50 bool operator==(const VisitRaceKey& other) const
51 {
52 return m_cell == other.m_cell
53 && m_raceName == other.m_raceName;
54 }
55
56 bool operator!=(const VisitRaceKey& other) const
57 {
58 return !(*this == other);
59 }
60
61 explicit operator bool() const
62 {
63 return *this != VisitRaceKey();
64 }
65
66 void dump(PrintStream& out) const;
67
68 JSCell* cell() const { return m_cell; }
69 const char* raceName() const { return m_raceName; }
70
71 bool isHashTableDeletedValue() const
72 {
73 return *this == VisitRaceKey(WTF::HashTableDeletedValue);
74 }
75
76 unsigned hash() const
77 {
78 return WTF::PtrHash<JSCell*>::hash(m_cell) ^ WTF::PtrHash<const char*>::hash(m_raceName);
79 }
80
81private:
82 static const char* m_deletedValueRaceName;
83
84 JSCell* m_cell { nullptr };
85 const char* m_raceName { nullptr };
86};
87
88struct VisitRaceKeyHash {
89 static unsigned hash(const VisitRaceKey& key) { return key.hash(); }
90 static bool equal(const VisitRaceKey& a, const VisitRaceKey& b) { return a == b; }
91 static constexpr bool safeToCompareToEmptyOrDeleted = true;
92};
93
94} // namespace JSC
95
96namespace WTF {
97
98template<typename T> struct DefaultHash;
99template<> struct DefaultHash<JSC::VisitRaceKey> {
100 typedef JSC::VisitRaceKeyHash Hash;
101};
102
103template<typename T> struct HashTraits;
104template<> struct HashTraits<JSC::VisitRaceKey> : SimpleClassHashTraits<JSC::VisitRaceKey> { };
105
106} // namespace WTF
107
108