parser/ParserArena.cpp

   1 /*
   2  * Copyright (C) 2009, 2010 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 #include "config.h"
  27 #include "ParserArena.h"
  28
  29 #include "Nodes.h"
  30 #include <wtf/PassOwnPtr.h>
  31
  32 namespace JSC {
  33
  34 ParserArena::ParserArena()
  35     : m_freeableMemory(0)
  36     , m_freeablePoolEnd(0)
  37     , m_identifierArena(adoptPtr(new IdentifierArena))
  38 {
  39 }
  40
  41 inline void* ParserArena::freeablePool()
  42 {
  43     ASSERT(m_freeablePoolEnd);
  44     return m_freeablePoolEnd - freeablePoolSize;
  45 }
  46
  47 inline void ParserArena::deallocateObjects()
  48 {
  49     if (m_freeablePoolEnd)
  50         fastFree(freeablePool());
  51
  52     size_t size = m_freeablePools.size();
  53     for (size_t i = 0; i < size; ++i)
  54         fastFree(m_freeablePools[i]);
  55
  56     size = m_deletableObjects.size();
  57     for (size_t i = 0; i < size; ++i) {
  58         ParserArenaDeletable* object = m_deletableObjects[i];
  59         object->~ParserArenaDeletable();
  60         fastFree(object);
  61     }
  62 }
  63
  64 ParserArena::~ParserArena()
  65 {
  66     deallocateObjects();
  67 }
  68
  69 bool ParserArena::contains(ParserArenaRefCounted* object) const
  70 {
  71     return m_refCountedObjects.find(object) != notFound;
  72 }
  73
  74 ParserArenaRefCounted* ParserArena::last() const
  75 {
  76     return m_refCountedObjects.last().get();
  77 }
  78
  79 void ParserArena::removeLast()
  80 {
  81     m_refCountedObjects.removeLast();
  82 }
  83
  84 void ParserArena::reset()
  85 {
  86     // Since this code path is used only when parsing fails, it's not bothering to reuse
  87     // any of the memory the arena allocated. We could improve that later if we want to
  88     // efficiently reuse the same arena.
  89
  90     deallocateObjects();
  91
  92     m_freeableMemory = 0;
  93     m_freeablePoolEnd = 0;
  94     m_identifierArena->clear();
  95     m_freeablePools.clear();
  96     m_deletableObjects.clear();
  97     m_refCountedObjects.clear();
  98 }
  99
 100 void ParserArena::allocateFreeablePool()
 101 {
 102     if (m_freeablePoolEnd)
 103         m_freeablePools.append(freeablePool());
 104
 105     char* pool = static_cast<char*>(fastMalloc(freeablePoolSize));
 106     m_freeableMemory = pool;
 107     m_freeablePoolEnd = pool + freeablePoolSize;
 108     ASSERT(freeablePool() == pool);
 109 }
 110
 111 bool ParserArena::isEmpty() const
 112 {
 113     return !m_freeablePoolEnd
 114         && m_identifierArena->isEmpty()
 115         && m_freeablePools.isEmpty()
 116         && m_deletableObjects.isEmpty()
 117         && m_refCountedObjects.isEmpty();
 118 }
 119
 120 void ParserArena::derefWithArena(PassRefPtr<ParserArenaRefCounted> object)
 121 {
 122     m_refCountedObjects.append(object);
 123 }
 124
 125 }