runtime/RegExpCache.cpp

   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 #include "config.h"
  29
  30 #include "RegExpCache.h"
  31 #include "RegExpObject.h"
  32
  33 namespace JSC {
  34
  35 RegExp* RegExpCache::lookupOrCreate(const UString& patternString, RegExpFlags flags)
  36 {
  37     RegExpKey key(flags, patternString);
  38     RegExpCacheMap::iterator result = m_weakCache.find(key);
  39     if (result != m_weakCache.end())
  40         return result->second.get();
  41     RegExp* regExp = new (m_globalData) RegExp(m_globalData, patternString, flags);
  42 #if ENABLE(REGEXP_TRACING)
  43     m_globalData->addRegExpToTrace(regExp);
  44 #endif
  45     // We need to do a second lookup to add the RegExp as
  46     // allocating it may have caused a gc cycle, which in
  47     // turn may have removed items from the cache.
  48     m_weakCache.add(key, Weak<RegExp>(*m_globalData, regExp, this));
  49     return regExp;
  50 }
  51
  52 RegExpCache::RegExpCache(JSGlobalData* globalData)
  53     : m_nextEntryInStrongCache(0)
  54     , m_globalData(globalData)
  55 {
  56 }
  57
  58 void RegExpCache::finalize(Handle<Unknown> handle, void*)
  59 {
  60     RegExp* regExp = static_cast<RegExp*>(handle.get().asCell());
  61     m_weakCache.remove(regExp->key());
  62     regExp->invalidateCode();
  63 }
  64
  65 void RegExpCache::addToStrongCache(RegExp* regExp)
  66 {
  67     UString pattern = regExp->pattern();
  68     if (pattern.length() > maxStrongCacheablePatternLength)
  69         return;
  70     m_strongCache[m_nextEntryInStrongCache].set(*m_globalData, regExp);
  71     m_nextEntryInStrongCache++;
  72     if (m_nextEntryInStrongCache == maxStrongCacheableEntries)
  73         m_nextEntryInStrongCache = 0;
  74 }
  75
  76 void RegExpCache::invalidateCode()
  77 {
  78     for (int i = 0; i < maxStrongCacheableEntries; i++)
  79         m_strongCache[i].clear();
  80     m_nextEntryInStrongCache = 0;
  81     RegExpCacheMap::iterator end = m_weakCache.end();
  82     for (RegExpCacheMap::iterator ptr = m_weakCache.begin(); ptr != end; ++ptr)
  83         ptr->second->invalidateCode();
  84 }
  85
  86 }