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 #include "StrongInlines.h"
  33
  34 namespace JSC {
  35
  36 RegExp* RegExpCache::lookupOrCreate(const UString& patternString, RegExpFlags flags)
  37 {
  38     RegExpKey key(flags, patternString);
  39     RegExpCacheMap::iterator result = m_weakCache.find(key);
  40     if (result != m_weakCache.end())
  41         return result->second.get();
  42     RegExp* regExp = RegExp::createWithoutCaching(*m_globalData, patternString, flags);
  43 #if ENABLE(REGEXP_TRACING)
  44     m_globalData->addRegExpToTrace(regExp);
  45 #endif
  46     // We need to do a second lookup to add the RegExp as
  47     // allocating it may have caused a gc cycle, which in
  48     // turn may have removed items from the cache.
  49     m_weakCache.add(key, PassWeak<RegExp>(regExp, this));
  50     return regExp;
  51 }
  52
  53 RegExpCache::RegExpCache(JSGlobalData* globalData)
  54     : m_nextEntryInStrongCache(0)
  55     , m_globalData(globalData)
  56 {
  57 }
  58
  59 void RegExpCache::finalize(Handle<Unknown> handle, void*)
  60 {
  61     RegExp* regExp = static_cast<RegExp*>(handle.get().asCell());
  62     m_weakCache.remove(regExp->key());
  63     regExp->invalidateCode();
  64 }
  65
  66 void RegExpCache::addToStrongCache(RegExp* regExp)
  67 {
  68     UString pattern = regExp->pattern();
  69     if (pattern.length() > maxStrongCacheablePatternLength)
  70         return;
  71     m_strongCache[m_nextEntryInStrongCache].set(*m_globalData, regExp);
  72     m_nextEntryInStrongCache++;
  73     if (m_nextEntryInStrongCache == maxStrongCacheableEntries)
  74         m_nextEntryInStrongCache = 0;
  75 }
  76
  77 void RegExpCache::invalidateCode()
  78 {
  79     for (int i = 0; i < maxStrongCacheableEntries; i++)
  80         m_strongCache[i].clear();
  81     m_nextEntryInStrongCache = 0;
  82     RegExpCacheMap::iterator end = m_weakCache.end();
  83     for (RegExpCacheMap::iterator ptr = m_weakCache.begin(); ptr != end; ++ptr)
  84         ptr->second->invalidateCode();
  85 }
  86
  87 }