/*

 * Copyright (C) 2008, 2009 Apple Inc. All rights reserved.

 *

 * Redistribution and use in source and binary forms, with or without

 * modification, are permitted provided that the following conditions

 * are met:

 *

 * 1.  Redistributions of source code must retain the above copyright

 *     notice, this list of conditions and the following disclaimer.

 * 2.  Redistributions in binary form must reproduce the above copyright

 *     notice, this list of conditions and the following disclaimer in the

 *     documentation and/or other materials provided with the distribution.

 * 3.  Neither the name of Apple Computer, Inc. ("Apple") nor the names of

 *     its contributors may be used to endorse or promote products derived

 *     from this software without specific prior written permission.

 *

 * THIS SOFTWARE IS PROVIDED BY APPLE AND ITS CONTRIBUTORS "AS IS" AND ANY

 * EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED

 * WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE

 * DISCLAIMED. IN NO EVENT SHALL APPLE OR ITS CONTRIBUTORS BE LIABLE FOR ANY

 * DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES

 * (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;

 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND

 * ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT

 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF

 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.

 */

#ifndef EvalCodeCache_h

#define EvalCodeCache_h

#include "Executable.h"

#include "JSGlobalObject.h"

#include "Nodes.h"

#include "Parser.h"

#include "SourceCode.h"

#include "UString.h"

#include <wtf/HashMap.h>

#include <wtf/RefPtr.h>

namespace JSC {

    class EvalCodeCache {

    public:

        PassRefPtr<EvalExecutable> get(ExecState* exec, const UString& evalSource, ScopeChainNode* scopeChain, JSValue& exceptionValue)

        {

            RefPtr<EvalExecutable> evalExecutable;

            if (evalSource.size() < maxCacheableSourceLength && (*scopeChain->begin())->isVariableObject())

                evalExecutable = m_cacheMap.get(evalSource.rep());

            if (!evalExecutable) {

                evalExecutable = EvalExecutable::create(exec, makeSource(evalSource));

                exceptionValue = evalExecutable->compile(exec, scopeChain);

                if (exceptionValue)

                    return 0;

                if (evalSource.size() < maxCacheableSourceLength && (*scopeChain->begin())->isVariableObject() && m_cacheMap.size() < maxCacheEntries)

                    m_cacheMap.set(evalSource.rep(), evalExecutable);

            }

            return evalExecutable.release();

        }

        bool isEmpty() const { return m_cacheMap.isEmpty(); }

    private:

        static const int maxCacheableSourceLength = 256;

        static const int maxCacheEntries = 64;

        typedef HashMap<RefPtr<UString::Rep>, RefPtr<EvalExecutable> > EvalCacheMap;

        EvalCacheMap m_cacheMap;

    };

} // namespace JSC

#endif // EvalCodeCache_h