1/*
2 * Copyright (C) 2010 University of Szeged
3 * Copyright (C) 2010 Renata Hodovan (hodovan@inf.u-szeged.hu)
4 * All rights reserved.
5 *
6 * Redistribution and use in source and binary forms, with or without
7 * modification, are permitted provided that the following conditions
8 * are met:
9 * 1. Redistributions of source code must retain the above copyright
10 * notice, this list of conditions and the following disclaimer.
11 * 2. Redistributions in binary form must reproduce the above copyright
12 * notice, this list of conditions and the following disclaimer in the
13 * documentation and/or other materials provided with the distribution.
14 *
15 * THIS SOFTWARE IS PROVIDED BY UNIVERSITY OF SZEGED ``AS IS'' AND ANY
16 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
17 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
18 * PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL UNIVERSITY OF SZEGED OR
19 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
20 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
21 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
22 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
23 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
25 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
26 */
27
28#pragma once
29
30#include "RegExp.h"
31#include "RegExpKey.h"
32#include "Strong.h"
33#include "Weak.h"
34#include <array>
35#include <wtf/HashMap.h>
36
37namespace JSC {
38
39namespace Yarr {
40enum class Flags : uint8_t;
41}
42
43class RegExpCache : private WeakHandleOwner {
44 WTF_MAKE_FAST_ALLOCATED;
45
46 friend class RegExp;
47 typedef HashMap<RegExpKey, Weak<RegExp>> RegExpCacheMap;
48
49public:
50 RegExpCache(VM* vm);
51 void deleteAllCode();
52
53 RegExp* ensureEmptyRegExp(VM& vm)
54 {
55 if (LIKELY(m_emptyRegExp))
56 return m_emptyRegExp.get();
57 return ensureEmptyRegExpSlow(vm);
58 }
59
60private:
61
62 static const unsigned maxStrongCacheablePatternLength = 256;
63
64 static const int maxStrongCacheableEntries = 32;
65
66 void finalize(Handle<Unknown>, void* context) override;
67
68 RegExp* ensureEmptyRegExpSlow(VM&);
69
70 RegExp* lookupOrCreate(const WTF::String& patternString, OptionSet<Yarr::Flags>);
71 void addToStrongCache(RegExp*);
72 RegExpCacheMap m_weakCache; // Holds all regular expressions currently live.
73 int m_nextEntryInStrongCache;
74 std::array<Strong<RegExp>, maxStrongCacheableEntries> m_strongCache; // Holds a select few regular expressions that have compiled and executed
75 Strong<RegExp> m_emptyRegExp;
76 VM* m_vm;
77};
78
79} // namespace JSC
80