// Copyright (c) 2005-2009 Nokia Corporation and/or its subsidiary(-ies).

// All rights reserved.

// This component and the accompanying materials are made available

// under the terms of "Eclipse Public License v1.0"

// which accompanies this distribution, and is available

// at the URL "http://www.eclipse.org/legal/epl-v10.html".

//

// Initial Contributors:

// Nokia Corporation - initial contribution.

//

// Contributors:

//

// Description:

//

#ifndef BYTE_PAIR_H

#define BYTE_PAIR_H

#ifdef __VC32__

#ifdef __MSVCDOTNET__

#include <strstream>

#include <iomanip>

#else //!__MSVCDOTNET__

#include <strstrea.h>

#include <iomanip.h>

#endif //__MSVCDOTNET__

#else // !__VC32__

#ifdef __TOOLS2__ 

#include <sstream>

#include <iomanip>

using namespace std;

#else

#include <strstream.h>

#include <iomanip.h>

#endif

#endif // __VC32__

#include <e32cmn.h>

const TInt MaxBlockSize = 0x1000;

class CBytePair {

    private:

        TBool iFastCompress;

        TUint16 PairCount[0x10000];

        TUint16 PairBuffer[MaxBlockSize*2];

        TInt PairsFound;

        TUint16 GlobalPairs[0x10000];

        TUint16 GlobalTokenCounts[0x100];

        TUint16 ByteCount[0x100+4];

        void CountBytes(TUint8* data, TInt size) {

            memset(ByteCount,0,sizeof(ByteCount));

            TUint8* dataEnd = data+size;

            while(data<dataEnd)

                ++ByteCount[*data++];

        }

        inline void ByteUsed(TInt b) {

            ByteCount[b] = 0xffff;

        }

        int TieBreak(int b1,int b2) {

            return -ByteCount[b1]-ByteCount[b2];

        }

        void InitPairCount(TUint8* data, TInt size, TInt minFrequency, TInt marker);

        TInt MostCommonPair(TInt& pair);

        TInt LeastCommonByte(TInt& byte);

    public:

        CBytePair(TBool fastCompress) {

            iFastCompress = fastCompress;

            memset(GlobalPairs,0,sizeof(GlobalPairs));

            memset(GlobalTokenCounts,0,sizeof(GlobalTokenCounts));

        }

        TInt Compress(TUint8* dst, TUint8* src, TInt size);

        TInt Decompress(TUint8* dst, TInt dstSize, TUint8* src, TInt srcSize, TUint8*& srcNext);

};

TInt BytePairCompress(TUint8* dst, TUint8* src, TInt size, CBytePair *aBPE);

#endif