/*

 * Copyright (C) 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.

 *

 * THIS SOFTWARE IS PROVIDED BY APPLE INC. ``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 INC. OR

 * 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 NumericStrings_h

#define NumericStrings_h

#include "UString.h"

#include <wtf/FixedArray.h>

#include <wtf/HashFunctions.h>

namespace JSC {

    class NumericStrings {

    public:

        UString add(double d)

        {

            CacheEntry<double>& entry = lookup(d);

            if (d == entry.key && !entry.value.isNull())

                return entry.value;

            entry.key = d;

            entry.value = UString::from(d);

            return entry.value;

        }

        UString add(int i)

        {

            if (static_cast<unsigned>(i) < cacheSize)

                return lookupSmallString(static_cast<unsigned>(i));

            CacheEntry<int>& entry = lookup(i);

            if (i == entry.key && !entry.value.isNull())

                return entry.value;

            entry.key = i;

            entry.value = UString::from(i);

            return entry.value;

        }

        UString add(unsigned i)

        {

            if (i < cacheSize)

                return lookupSmallString(static_cast<unsigned>(i));

            CacheEntry<unsigned>& entry = lookup(i);

            if (i == entry.key && !entry.value.isNull())

                return entry.value;

            entry.key = i;

            entry.value = UString::from(i);

            return entry.value;

        }

    private:

        static const size_t cacheSize = 64;

        template<typename T>

        struct CacheEntry {

            T key;

            UString value;

        };

        CacheEntry<double>& lookup(double d) { return doubleCache[WTF::FloatHash<double>::hash(d) & (cacheSize - 1)]; }

        CacheEntry<int>& lookup(int i) { return intCache[WTF::IntHash<int>::hash(i) & (cacheSize - 1)]; }

        CacheEntry<unsigned>& lookup(unsigned i) { return unsignedCache[WTF::IntHash<unsigned>::hash(i) & (cacheSize - 1)]; }

        const UString& lookupSmallString(unsigned i)

        {

            ASSERT(i < cacheSize);

            if (smallIntCache[i].isNull())

                smallIntCache[i] = UString::from(i);

            return smallIntCache[i];

        }

        FixedArray<CacheEntry<double>, cacheSize> doubleCache;

        FixedArray<CacheEntry<int>, cacheSize> intCache;

        FixedArray<CacheEntry<unsigned>, cacheSize> unsignedCache;

        FixedArray<UString, cacheSize> smallIntCache;

    };

} // namespace JSC

#endif // NumericStrings_h