parser/ParserArena.h

   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
  32 namespace JSC {
  33
  34     class ParserArenaDeletable;
  35     class ParserArenaRefCounted;
  36
  37     class IdentifierArena : public FastAllocBase {
  38     public:
  39         ALWAYS_INLINE const Identifier& makeIdentifier(JSGlobalData*, const UChar* characters, size_t length);
  40         const Identifier& makeNumericIdentifier(JSGlobalData*, double number);
  41
  42         void clear() { m_identifiers.clear(); }
  43         bool isEmpty() const { return m_identifiers.isEmpty(); }
  44
  45     private:
  46         typedef SegmentedVector<Identifier, 64> IdentifierVector;
  47         IdentifierVector m_identifiers;
  48     };
  49
  50     ALWAYS_INLINE const Identifier& IdentifierArena::makeIdentifier(JSGlobalData* globalData, const UChar* characters, size_t length)
  51     {
  52         m_identifiers.append(Identifier(globalData, characters, length));
  53         return m_identifiers.last();
  54     }
  55
  56     inline const Identifier& IdentifierArena::makeNumericIdentifier(JSGlobalData* globalData, double number)
  57     {
  58         m_identifiers.append(Identifier(globalData, UString::from(number)));
  59         return m_identifiers.last();
  60     }
  61
  62     class ParserArena : Noncopyable {
  63     public:
  64         ParserArena();
  65         ~ParserArena();
  66
  67         void swap(ParserArena& otherArena)
  68         {
  69             std::swap(m_freeableMemory, otherArena.m_freeableMemory);
  70             std::swap(m_freeablePoolEnd, otherArena.m_freeablePoolEnd);
  71             m_identifierArena.swap(otherArena.m_identifierArena);
  72             m_freeablePools.swap(otherArena.m_freeablePools);
  73             m_deletableObjects.swap(otherArena.m_deletableObjects);
  74             m_refCountedObjects.swap(otherArena.m_refCountedObjects);
  75         }
  76
  77         void* allocateFreeable(size_t size)
  78         {
  79             ASSERT(size);
  80             ASSERT(size <= freeablePoolSize);
  81             size_t alignedSize = alignSize(size);
  82             ASSERT(alignedSize <= freeablePoolSize);
  83             if (UNLIKELY(static_cast<size_t>(m_freeablePoolEnd - m_freeableMemory) < alignedSize))
  84                 allocateFreeablePool();
  85             void* block = m_freeableMemory;
  86             m_freeableMemory += alignedSize;
  87             return block;
  88         }
  89
  90         void* allocateDeletable(size_t size)
  91         {
  92             ParserArenaDeletable* deletable = static_cast<ParserArenaDeletable*>(fastMalloc(size));
  93             m_deletableObjects.append(deletable);
  94             return deletable;
  95         }
  96
  97         void derefWithArena(PassRefPtr<ParserArenaRefCounted>);
  98         bool contains(ParserArenaRefCounted*) const;
  99         ParserArenaRefCounted* last() const;
 100         void removeLast();
 101
 102         bool isEmpty() const;
 103         void reset();
 104
 105         IdentifierArena& identifierArena() { return *m_identifierArena; }
 106
 107     private:
 108         static const size_t freeablePoolSize = 8000;
 109
 110         static size_t alignSize(size_t size)
 111         {
 112             return (size + sizeof(WTF::AllocAlignmentInteger) - 1) & ~(sizeof(WTF::AllocAlignmentInteger) - 1);
 113         }
 114
 115         void* freeablePool();
 116         void allocateFreeablePool();
 117         void deallocateObjects();
 118
 119         char* m_freeableMemory;
 120         char* m_freeablePoolEnd;
 121
 122         OwnPtr<IdentifierArena> m_identifierArena;
 123         Vector<void*> m_freeablePools;
 124         Vector<ParserArenaDeletable*> m_deletableObjects;
 125         Vector<RefPtr<ParserArenaRefCounted> > m_refCountedObjects;
 126     };
 127
 128 }
 129
 130 #endif