1/*
2 * Copyright (C) 2009 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. ``AS IS'' AND ANY
14 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
15 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
16 * PURPOSE ARE DISCLAIMED.  IN NO EVENT SHALL APPLE INC. OR
17 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL,
18 * EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO,
19 * PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
20 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY
21 * OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
22 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
23 * OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
24 */
25
26#ifndef ParserArena_h
27#define ParserArena_h
28
29#include "Identifier.h"
30#include <wtf/SegmentedVector.h>
31
32namespace JSC {
33
34    class ParserArenaDeletable;
35    class ParserArenaRefCounted;
36
37    class IdentifierArena {
38        WTF_MAKE_FAST_ALLOCATED;
39    public:
40        ALWAYS_INLINE const Identifier& makeIdentifier(JSGlobalData*, const UChar* characters, size_t length);
41        const Identifier& makeNumericIdentifier(JSGlobalData*, double number);
42
43        void clear() { m_identifiers.clear(); }
44        bool isEmpty() const { return m_identifiers.isEmpty(); }
45
46    private:
47        typedef SegmentedVector<Identifier, 64> IdentifierVector;
48        IdentifierVector m_identifiers;
49    };
50
51    ALWAYS_INLINE const Identifier& IdentifierArena::makeIdentifier(JSGlobalData* globalData, const UChar* characters, size_t length)
52    {
53        m_identifiers.append(Identifier(globalData, characters, length));
54        return m_identifiers.last();
55    }
56
57    inline const Identifier& IdentifierArena::makeNumericIdentifier(JSGlobalData* globalData, double number)
58    {
59        m_identifiers.append(Identifier(globalData, UString::number(number)));
60        return m_identifiers.last();
61    }
62
63    class ParserArena {
64        WTF_MAKE_NONCOPYABLE(ParserArena);
65    public:
66        ParserArena();
67        ~ParserArena();
68
69        void swap(ParserArena& otherArena)
70        {
71            std::swap(m_freeableMemory, otherArena.m_freeableMemory);
72            std::swap(m_freeablePoolEnd, otherArena.m_freeablePoolEnd);
73            m_identifierArena.swap(otherArena.m_identifierArena);
74            m_freeablePools.swap(otherArena.m_freeablePools);
75            m_deletableObjects.swap(otherArena.m_deletableObjects);
76            m_refCountedObjects.swap(otherArena.m_refCountedObjects);
77        }
78
79        void* allocateFreeable(size_t size)
80        {
81            ASSERT(size);
82            ASSERT(size <= freeablePoolSize);
83            size_t alignedSize = alignSize(size);
84            ASSERT(alignedSize <= freeablePoolSize);
85            if (UNLIKELY(static_cast<size_t>(m_freeablePoolEnd - m_freeableMemory) < alignedSize))
86                allocateFreeablePool();
87            void* block = m_freeableMemory;
88            m_freeableMemory += alignedSize;
89            return block;
90        }
91
92        void* allocateDeletable(size_t size)
93        {
94            ParserArenaDeletable* deletable = static_cast<ParserArenaDeletable*>(fastMalloc(size));
95            m_deletableObjects.append(deletable);
96            return deletable;
97        }
98
99        void derefWithArena(PassRefPtr<ParserArenaRefCounted>);
100        bool contains(ParserArenaRefCounted*) const;
101        ParserArenaRefCounted* last() const;
102        void removeLast();
103
104        bool isEmpty() const;
105        void reset();
106
107        IdentifierArena& identifierArena() { return *m_identifierArena; }
108
109    private:
110        static const size_t freeablePoolSize = 8000;
111
112        static size_t alignSize(size_t size)
113        {
114            return (size + sizeof(WTF::AllocAlignmentInteger) - 1) & ~(sizeof(WTF::AllocAlignmentInteger) - 1);
115        }
116
117        void* freeablePool();
118        void allocateFreeablePool();
119        void deallocateObjects();
120
121        char* m_freeableMemory;
122        char* m_freeablePoolEnd;
123
124        OwnPtr<IdentifierArena> m_identifierArena;
125        Vector<void*> m_freeablePools;
126        Vector<ParserArenaDeletable*> m_deletableObjects;
127        Vector<RefPtr<ParserArenaRefCounted> > m_refCountedObjects;
128    };
129
130}
131
132#endif
133