/*
 * 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 <wtf/FixedArray.h>
#include <wtf/HashFunctions.h>
#include <wtf/text/WTFString.h>

namespace JSC {

class NumericStrings {
public:
	ALWAYS_INLINE const String& add(double d)
	{
		CacheEntry<double>& entry = lookup(d);
		if (d == entry.key && !entry.value.isNull())
			return entry.value;
		entry.key = d;
		entry.value = String::numberToStringECMAScript(d);
		return entry.value;
	}

	ALWAYS_INLINE const String& 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 = String::number(i);
		return entry.value;
	}

	ALWAYS_INLINE const String& 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 = String::number(i);
		return entry.value;
	}

	void reset(){
		for(unsigned i = 0; i < cacheSize; ++i){
			doubleCache[i].value = String();
			intCache[i].value = String();
			unsignedCache[i].value = String();
			smallIntCache[i] = String();
		}
	}

private:
	static const size_t cacheSize = 64;

	template<typename T>
	struct CacheEntry {
		T key;
		String 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)]; }
	ALWAYS_INLINE const String& lookupSmallString(unsigned i)
	{
		ASSERT(i < cacheSize);
		if (smallIntCache[i].isNull())
			smallIntCache[i] = String::number(i);
		return smallIntCache[i];
	}

	FixedArray<CacheEntry<double>, cacheSize> doubleCache;
	FixedArray<CacheEntry<int>, cacheSize> intCache;
	FixedArray<CacheEntry<unsigned>, cacheSize> unsignedCache;
	FixedArray<String, cacheSize> smallIntCache;
};

} // namespace JSC

#endif // NumericStrings_h
