1/*
2 * Copyright (C) 2018 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 "ProcessIdentifier.h"
29#include <wtf/DebugUtilities.h>
30#include <wtf/Hasher.h>
31#include <wtf/text/StringConcatenateNumbers.h>
32
33namespace WebCore {
34
35struct BackForwardItemIdentifier {
36 ProcessIdentifier processIdentifier;
37 enum ItemIdentifierType { };
38 ObjectIdentifier<ItemIdentifierType> itemIdentifier;
39
40 unsigned hash() const;
41
42 template<class Encoder> void encode(Encoder&) const;
43 template<class Decoder> static Optional<BackForwardItemIdentifier> decode(Decoder&);
44
45#if !LOG_DISABLED
46 const char* logString() const;
47#endif
48};
49
50#if !LOG_DISABLED
51
52inline const char* BackForwardItemIdentifier::logString() const
53{
54 return debugString(makeString(processIdentifier.toUInt64(), '-', itemIdentifier.toUInt64()));
55}
56
57#endif
58
59inline bool operator==(const BackForwardItemIdentifier& a, const BackForwardItemIdentifier& b)
60{
61 return a.processIdentifier == b.processIdentifier && a.itemIdentifier == b.itemIdentifier;
62}
63
64template<class Encoder>
65void BackForwardItemIdentifier::encode(Encoder& encoder) const
66{
67 encoder << processIdentifier << itemIdentifier;
68}
69
70template<class Decoder>
71Optional<BackForwardItemIdentifier> BackForwardItemIdentifier::decode(Decoder& decoder)
72{
73 Optional<ProcessIdentifier> processIdentifier;
74 decoder >> processIdentifier;
75 if (!processIdentifier)
76 return WTF::nullopt;
77
78 Optional<ObjectIdentifier<ItemIdentifierType>> itemIdentifier;
79 decoder >> itemIdentifier;
80 if (!itemIdentifier)
81 return WTF::nullopt;
82
83 return { { WTFMove(*processIdentifier), WTFMove(*itemIdentifier) } };
84}
85
86inline unsigned BackForwardItemIdentifier::hash() const
87{
88 return computeHash(processIdentifier.toUInt64(), itemIdentifier.toUInt64());
89}
90
91} // namespace WebCore
92
93namespace WTF {
94
95struct BackForwardItemIdentifierHash {
96 static unsigned hash(const WebCore::BackForwardItemIdentifier& key) { return key.hash(); }
97 static bool equal(const WebCore::BackForwardItemIdentifier& a, const WebCore::BackForwardItemIdentifier& b) { return a == b; }
98 static const bool safeToCompareToEmptyOrDeleted = true;
99};
100
101template<> struct HashTraits<WebCore::BackForwardItemIdentifier> : GenericHashTraits<WebCore::BackForwardItemIdentifier> {
102 static WebCore::BackForwardItemIdentifier emptyValue() { return { }; }
103
104 static void constructDeletedValue(WebCore::BackForwardItemIdentifier& slot) { slot.processIdentifier = ObjectIdentifier<WebCore::ProcessIdentifierType>(HashTableDeletedValue); }
105
106 static bool isDeletedValue(const WebCore::BackForwardItemIdentifier& slot) { return slot.processIdentifier.toUInt64() == std::numeric_limits<uint64_t>::max(); }
107};
108
109template<> struct DefaultHash<WebCore::BackForwardItemIdentifier> {
110 typedef BackForwardItemIdentifierHash Hash;
111};
112
113} // namespace WTF
114