1/*
2 * Copyright (C) 2017 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/HashTraits.h>
29#include <wtf/RunLoop.h>
30
31namespace WTF {
32
33struct CallbackIDHash;
34
35}
36
37namespace WebKit {
38
39class CallbackID {
40public:
41 ALWAYS_INLINE explicit CallbackID()
42 { }
43
44 ALWAYS_INLINE CallbackID(const CallbackID& otherID)
45 : m_id(otherID.m_id)
46 {
47 ASSERT(HashTraits<uint64_t>::emptyValue() != m_id && !HashTraits<uint64_t>::isDeletedValue(m_id));
48 }
49
50 ALWAYS_INLINE CallbackID& operator=(const CallbackID& otherID)
51 {
52 m_id = otherID.m_id;
53 return *this;
54 }
55
56 bool operator==(const CallbackID& other) const { return m_id == other.m_id; }
57
58 uint64_t toInteger() const { return m_id; }
59 ALWAYS_INLINE bool isValid() const { return isValidCallbackID(m_id); }
60 static ALWAYS_INLINE bool isValidCallbackID(uint64_t rawId)
61 {
62 return HashTraits<uint64_t>::emptyValue() != rawId && !HashTraits<uint64_t>::isDeletedValue(rawId);
63 }
64
65 static ALWAYS_INLINE CallbackID fromInteger(uint64_t rawId)
66 {
67 RELEASE_ASSERT(isValidCallbackID(rawId));
68 return CallbackID(rawId);
69 }
70
71 static CallbackID generateID()
72 {
73 ASSERT(RunLoop::isMain());
74 static uint64_t uniqueCallbackID = 1;
75 return CallbackID(uniqueCallbackID++);
76 }
77
78 template<class Encoder> void encode(Encoder& encoder) const
79 {
80 RELEASE_ASSERT(isValid());
81 encoder << m_id;
82 }
83
84 template<class Decoder> static Optional<CallbackID> decode(Decoder& decoder)
85 {
86 Optional<uint64_t> identifier;
87 decoder >> identifier;
88 if (!identifier)
89 return WTF::nullopt;
90 RELEASE_ASSERT(isValidCallbackID(*identifier));
91 return fromInteger(*identifier);
92 }
93
94private:
95 ALWAYS_INLINE explicit CallbackID(uint64_t newID)
96 : m_id(newID)
97 {
98 ASSERT(newID != HashTraits<uint64_t>::emptyValue());
99 }
100
101 friend class CallbackMap;
102 template <typename CallbackType> friend class SpecificCallbackMap;
103 friend class OptionalCallbackID;
104 friend struct WTF::CallbackIDHash;
105 friend HashTraits<WebKit::CallbackID>;
106
107 uint64_t m_id { HashTraits<uint64_t>::emptyValue() };
108};
109
110}
111
112namespace WTF {
113
114struct CallbackIDHash {
115 static unsigned hash(const WebKit::CallbackID& callbackID) { return intHash(callbackID.m_id); }
116 static bool equal(const WebKit::CallbackID& a, const WebKit::CallbackID& b) { return a.m_id == b.m_id; }
117 static const bool safeToCompareToEmptyOrDeleted = true;
118};
119template<> struct HashTraits<WebKit::CallbackID> : GenericHashTraits<WebKit::CallbackID> {
120 static WebKit::CallbackID emptyValue() { return WebKit::CallbackID(); }
121 static void constructDeletedValue(WebKit::CallbackID& slot) { slot = WebKit::CallbackID(std::numeric_limits<uint64_t>::max()); }
122 static bool isDeletedValue(const WebKit::CallbackID& slot) { return slot.m_id == std::numeric_limits<uint64_t>::max(); }
123};
124template<> struct DefaultHash<WebKit::CallbackID> {
125 typedef CallbackIDHash Hash;
126};
127
128}
129