1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
|
/*
* Copyright (C) 2025 Apple Inc. All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions
* are met:
* 1. Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* 2. Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
*
* THIS SOFTWARE IS PROVIDED BY APPLE INC. AND ITS CONTRIBUTORS ``AS IS''
* AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO,
* THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL APPLE INC. OR ITS CONTRIBUTORS
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF
* THE POSSIBILITY OF SUCH DAMAGE.
*/
#pragma once
#include "JSString.h"
#include <wtf/TZoneMalloc.h>
#include <wtf/text/AtomStringImpl.h>
namespace JSC {
class VM;
class ConcatKeyAtomStringCache {
WTF_MAKE_TZONE_ALLOCATED(ConcatKeyAtomStringCache);
WTF_MAKE_NONCOPYABLE(ConcatKeyAtomStringCache);
public:
enum class Mode : uint8_t {
Variable0,
Variable1,
Variable2,
Megamorphic,
};
static constexpr auto maxCapacity = 64;
static constexpr auto maxStringLengthForCache = 64;
ConcatKeyAtomStringCache(CodeBlock* owner, Mode mode)
: m_owner(owner)
, m_mode(mode)
{ }
template<typename Func>
JSString* getOrInsert(VM&, JSString*, JSString*, JSString*, const Func&);
struct CacheEntry {
static constexpr ptrdiff_t offsetOfKey()
{
return OBJECT_OFFSETOF(CacheEntry, m_key);
}
static constexpr ptrdiff_t offsetOfValue()
{
return OBJECT_OFFSETOF(CacheEntry, m_value);
}
WriteBarrier<JSString> m_key { };
WriteBarrier<JSString> m_value { };
};
static constexpr ptrdiff_t offsetOfQuickCache0()
{
return OBJECT_OFFSETOF(ConcatKeyAtomStringCache, m_quickCache);
}
static constexpr ptrdiff_t offsetOfQuickCache1()
{
return OBJECT_OFFSETOF(ConcatKeyAtomStringCache, m_quickCache) + sizeof(CacheEntry);
}
DECLARE_VISIT_AGGREGATE;
size_t size() const { return m_cache.size(); }
private:
CodeBlock* m_owner { nullptr };
std::array<CacheEntry, 2> m_quickCache { };
UncheckedKeyHashMap<Ref<AtomStringImpl>, JSString*> m_cache;
Mode m_mode { Mode::Megamorphic };
Lock m_lock;
};
} // namespace JSC
|
