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
  32 namespace JSC {
  33
  34 PassRefPtr<RegExp> RegExpCache::lookupOrCreate(const UString& patternString, const UString& flags)
  35 {
  36     if (patternString.size() < maxCacheablePatternLength) {
  37         pair<HashMap<RegExpKey, RefPtr<RegExp> >::iterator, bool> result = m_cacheMap.add(RegExpKey(flags, patternString), 0);
  38         if (!result.second)
  39             return result.first->second;
  40     }
  41     return create(patternString, flags);
  42 }
  43
  44 PassRefPtr<RegExp> RegExpCache::create(const UString& patternString, const UString& flags)
  45 {
  46     RefPtr<RegExp> regExp;
  47
  48     if (!flags.isNull())
  49         regExp = RegExp::create(m_globalData, patternString, flags);
  50     else
  51         regExp = RegExp::create(m_globalData, patternString);
  52
  53     if (patternString.size() >= maxCacheablePatternLength)
  54         return regExp;
  55
  56     ++m_nextKeyToEvict;
  57     if (m_nextKeyToEvict == maxCacheableEntries) {
  58         m_nextKeyToEvict = 0;
  59         m_isFull = true;
  60     }
  61     if (m_isFull)
  62         m_cacheMap.remove(RegExpKey(patternKeyArray[m_nextKeyToEvict].flagsValue, patternKeyArray[m_nextKeyToEvict].pattern));
  63
  64     RegExpKey key = RegExpKey(flags, patternString);
  65     m_cacheMap.set(key, regExp);
  66     patternKeyArray[m_nextKeyToEvict].flagsValue = key.flagsValue;
  67     patternKeyArray[m_nextKeyToEvict].pattern = patternString.rep();
  68     return regExp;
  69 }
  70
  71 RegExpCache::RegExpCache(JSGlobalData* globalData)
  72     : m_globalData(globalData)
  73     , m_nextKeyToEvict(-1)
  74     , m_isFull(false)
  75 {
  76 }
  77
  78 }