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