1/* 2 * Copyright (C) 2008, 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 * 8 * 1. Redistributions of source code must retain the above copyright 9 * notice, this list of conditions and the following disclaimer. 10 * 2. Redistributions in binary form must reproduce the above copyright 11 * notice, this list of conditions and the following disclaimer in the 12 * documentation and/or other materials provided with the distribution. 13 * 3. Neither the name of Apple Inc. ("Apple") nor the names of 14 * its contributors may be used to endorse or promote products derived 15 * from this software without specific prior written permission. 16 * 17 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY 18 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED 19 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE 20 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY 21 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES 22 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; 23 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND 24 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT 25 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF 26 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. 27 */ 28 29#ifndef EvalCodeCache_h 30#define EvalCodeCache_h 31 32#include "Executable.h" 33#include "JSGlobalObject.h" 34#include "SourceCode.h" 35#include <wtf/HashMap.h> 36#include <wtf/RefPtr.h> 37#include <wtf/text/StringHash.h> 38 39namespace JSC { 40 41 class SlotVisitor; 42 43 class EvalCodeCache { 44 public: 45 EvalExecutable* tryGet(bool inStrictContext, const String& evalSource, JSScope* scope) 46 { 47 if (!inStrictContext && evalSource.length() < maxCacheableSourceLength && scope->begin()->isVariableObject()) 48 return m_cacheMap.get(evalSource.impl()).get(); 49 return 0; 50 } 51 52 EvalExecutable* getSlow(ExecState* exec, ScriptExecutable* owner, bool inStrictContext, const String& evalSource, JSScope* scope) 53 { 54 EvalExecutable* evalExecutable = EvalExecutable::create(exec, makeSource(evalSource), inStrictContext); 55 if (!evalExecutable) 56 return 0; 57 58 if (!inStrictContext && evalSource.length() < maxCacheableSourceLength && scope->begin()->isVariableObject() && m_cacheMap.size() < maxCacheEntries) 59 m_cacheMap.set(evalSource.impl(), WriteBarrier<EvalExecutable>(exec->vm(), owner, evalExecutable)); 60 61 return evalExecutable; 62 } 63 64 bool isEmpty() const { return m_cacheMap.isEmpty(); } 65 66 void visitAggregate(SlotVisitor&); 67 68 void clear() 69 { 70 m_cacheMap.clear(); 71 } 72 73 private: 74 static const unsigned maxCacheableSourceLength = 256; 75 static const int maxCacheEntries = 64; 76 77 typedef HashMap<RefPtr<StringImpl>, WriteBarrier<EvalExecutable>> EvalCacheMap; 78 EvalCacheMap m_cacheMap; 79 }; 80 81} // namespace JSC 82 83#endif // EvalCodeCache_h 84