/*

* 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 the License "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

  #include <iomanip>

 #else //!__MSVCDOTNET__

  #include <strstrea.h>

  #include <iomanip.h>

 #endif //__MSVCDOTNET__

#else // !__VC32__

#ifdef __TOOLS2__ 

#include <sstream>

#include <iomanip>

#include <iostream>

using namespace std;

#else

 #include <strstream.h>

 #include <iomanip.h>

 #endif

#endif // __VC32__

//#include <myassert.h>

//#define DEBUG_ASSERT

#ifdef DEBUG_ASSERT

void myassert(int c);

#else

#define myassert(c) 

#endif

#include <e32cmn.h> 

typedef struct {

    TUint16 Count;

    TUint16 Index; 

} TPairCountIndex;

typedef struct {

    TUint16 Pair;

    TUint16 Next;

    TUint16 Prev;

    TUint16 Pos;

} TPair;

typedef struct {

    TUint16 Pos;

    TUint16 Next;

} TPos;

const TInt MaxBlockSize = 0x1000;

const TUint16 PosEnd = 0xffff;

const TUint16 PosHead = 0xfffe;

const TUint8 ByteRemoved = 'R';

const TUint8 ByteMarked = 'M';

const TUint8 ByteHead = 'H';

const TUint8 ByteTail = 'T';

const TUint8 ByteNew = 'N';

class CBytePair {

    private:

        TInt    marker;

        TInt    markerCount;

        TUint8  Mask[MaxBlockSize];

        TUint16 ByteCount[0x100];

        TUint16 ByteIndex[0x100];

        TUint16 BytePos[MaxBlockSize];

        TPairCountIndex PairCount[0x10000];

        TPair   PairBuffer[MaxBlockSize*2];

        TInt    PairBufferNext;

        TPos    PairPos[MaxBlockSize*3];

        TUint16 PairPosNext;

        TUint16 PairLists[MaxBlockSize/2+2];

        TInt    PairListHigh;

        void CountBytes(TUint8* data, TInt size) {

	    memset(reinterpret_cast<char*>(ByteCount),0,sizeof(ByteCount));

            memset(reinterpret_cast<char*>(ByteIndex),0xff,sizeof(ByteIndex));

            memset(reinterpret_cast<char*>(BytePos),0xff, sizeof(BytePos));

            TUint8* dataEnd = data + size;

            int pos = 0;

            while(data < dataEnd) {

                BytePos[pos] = ByteIndex[*data];

                ByteIndex[*data] = (TUint16)pos;

                pos ++;

                ++ByteCount[*data++];

            }

        }

        inline void ByteUsed(TInt b) {

            ByteCount[b] = 0xffff;

        }

        int TieBreak(int b1,int b2) {

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

        }

        void SortN(TUint16 *a, TInt n);

        void InsertN(TUint16 *a, TInt n, TUint16 v);

        TInt PosN(TUint16 index, TInt minFrequency);

        void Initialize(TUint8* data, TInt size);

        TInt MostCommonPair(TInt& pair, TInt minFrequency);

        TInt LeastCommonByte(TInt& byte);

        inline void InsertPair(const TUint16 pair, const TUint16 pos) {

            //ClockInsert1 = clock();

            //cout << "Pair:" << hex << setw(4) << setfill ('0') << pair << endl;

            TUint16 count = PairCount[pair].Count;

            if (0==count) {

                PairCount[pair].Index = (TUint16)PairBufferNext;

                if (PairLists[1] != PosEnd) {

                    PairBuffer[PairLists[1]].Prev = (TUint16)PairBufferNext;

                }

                PairBuffer[PairBufferNext].Next = PairLists[1];

                PairBuffer[PairBufferNext].Prev = PosHead;

                PairLists[1] = (TUint16)PairBufferNext;

                PairBuffer[PairBufferNext].Pair = pair;

                PairBuffer[PairBufferNext].Pos = PairPosNext;

                PairBufferNext ++;

                myassert(PairBufferNext < MaxBlockSize*2);

                PairPos[PairPosNext].Pos = pos; 

                PairPos[PairPosNext].Next = PosEnd;

            } else {

                TUint16 index = PairCount[pair].Index;

                if (PairBuffer[index].Next == PosEnd){

                    if (PairBuffer[index].Prev == PosHead){

                        PairLists[count] = PosEnd;

                    } else {

                        PairBuffer[PairBuffer[index].Prev].Next = PosEnd;

                    }

                } else {

                    if (PairBuffer[index].Prev == PosHead){

                        PairLists[count] = PairBuffer[index].Next;

                        PairBuffer[PairBuffer[index].Next].Prev = PosHead;

                    } else {

                        PairBuffer[PairBuffer[index].Prev].Next = PairBuffer[index].Next;

                        PairBuffer[PairBuffer[index].Next].Prev = PairBuffer[index].Prev;

                    }

                }

                if (PairLists[count+1] != PosEnd){

                    PairBuffer[PairLists[count+1]].Prev = index;

                    PairBuffer[index].Next = PairLists[count+1];

                    PairBuffer[index].Prev = PosHead;

                    PairLists[count+1] = index;

                }else{

                    PairLists[count+1] = index;

                    PairBuffer[index].Next = PosEnd;

                    PairBuffer[index].Prev = PosHead;

                }

                PairPos[PairPosNext].Pos = pos;

                PairPos[PairPosNext].Next = PairBuffer[index].Pos;

                PairBuffer[index].Pos = PairPosNext;

            }

            PairPosNext ++;

            myassert(PairPosNext < MaxBlockSize*3);

            PairCount[pair].Count ++;

            if (PairCount[pair].Count > PairListHigh) 

                PairListHigh = PairCount[pair].Count; 

        }

        inline void RemovePair(const TUint16 pair, const TUint16 pos){

            //ClockRemove1 = clock();

            TUint16 count = PairCount[pair].Count;

            TUint16 index = PairCount[pair].Index;

            if (count == 1 ) {

                PairCount[pair].Count = 0;

                PairCount[pair].Index = PosEnd;

                return;

            }

            myassert(index != PosEnd);

            TUint16 *posnextp = &PairBuffer[index].Pos;

            while (*posnextp != PosEnd){

                if (PairPos[*posnextp].Pos == pos)

                    break;

                posnextp = &PairPos[*posnextp].Next;

            }

            myassert(*posnextp != PosEnd);

            *posnextp = PairPos[*posnextp].Next;

            if (PairBuffer[index].Next == PosEnd){

                if (PairBuffer[index].Prev == PosHead){

                    PairLists[count] = PosEnd;

                } else {

                    PairBuffer[PairBuffer[index].Prev].Next = PosEnd;

                }

            } else {

                if (PairBuffer[index].Prev == PosHead){

                    PairLists[count] = PairBuffer[index].Next;

                    PairBuffer[PairBuffer[index].Next].Prev = PosHead;

                } else {

                    PairBuffer[PairBuffer[index].Prev].Next = PairBuffer[index].Next;

                    PairBuffer[PairBuffer[index].Next].Prev = PairBuffer[index].Prev;

                }

            }

            myassert(PairCount[pair].Count > 0);

            PairCount[pair].Count --;

            if (PairCount[pair].Count == 0)

                PairCount[pair].Index = PosEnd;

            count = PairCount[pair].Count;

            if (count > 0) {

                if (PairLists[count] != PosEnd){

                    PairBuffer[PairLists[count]].Prev = index;

                    PairBuffer[index].Next = PairLists[count];

                    PairBuffer[index].Prev = PosHead;

                    PairLists[count] = index;

                }else{

                    PairLists[count] = index;

                    PairBuffer[index].Next = PosEnd;

                    PairBuffer[index].Prev = PosHead;

                }

            }            

            while (PairLists[PairListHigh] == PosEnd) {

                PairListHigh --;

            }             

        }

        inline void GetPairBackward (TUint8 *data, TUint16 pos, TUint16 &pairpos, TUint16 &pair) {

            myassert(pos <MaxBlockSize);

            myassert(Mask[pos] != ByteMarked);

            myassert(Mask[pos] != ByteRemoved);

            TUint8 b = data[pos];

            if (pos == 0) {

                pair = 0;

                pairpos = PosEnd;

                return;

            }

            pos --;

            while ((pos>0) && (Mask[pos] == ByteRemoved)){

                pos --;

            }

            if ((Mask[pos] == ByteRemoved) || (Mask[pos] == ByteMarked)) {

                pair = 0;

                pairpos = PosEnd;

            } else {

                pair = (TUint16)((b << 8) | data[pos]);

                pairpos = pos;

            }

        }

        inline void GetPairForward (TUint8 *data, TUint16 pos, TInt size, TUint16 &pairpos, TUint16 &pair) {

            myassert(Mask[pos] != ByteMarked);

            myassert(Mask[pos] != ByteRemoved);

            myassert(pos < size);

            TUint8 b = data[pos];

            pairpos = pos;

            pos ++;

            while ((pos < size) && (Mask[pos] == ByteRemoved))

                pos++;

            if ((pos == size) || (Mask[pos] == ByteMarked)) {

                pair = 0;

                pairpos = PosEnd;

            } else {

                pair = (TUint16)(b | (data[pos] << 8));

            }

        }

#ifdef  __TOOLS2__        

        void DumpList(TUint8 *data, TInt size) {

            int i, j;

            cout << "src: " << dec << size << " bytes"<< endl;

            for (i=0;i<size;i+=16){

                cout << endl;

                cout << hex;

                cout << setfill('0') << setw(4) << right << i << " ";

                for (j=0;j<16;j++) {

                    cout << setfill ('0') << setw(2) << right << (unsigned int)data[i+j] << " ";

                }

                cout << "    ";

                for (j=0;j<16;j++) {

                    char c = isgraph(data[i+j]) ? data[i+j]:'.';

                    cout << c;

                }

            }

            cout << endl;

            for (i=0;i<256;i+=16){

                cout << endl << hex << setfill('0') << setw(2) <<right <<i << " ";

                for (j=0;j<16;j++) {

                    cout << setfill ('0') << setw(4) << right << (unsigned int)ByteIndex[i+j] << " ";

                }

            }

            cout << endl;

            for (i=0;i<256;i++){

                cout << "Byte: <" << i << "> Count: " << ByteCount[i];

                TUint16 pos = ByteIndex[i];

                int j = 0;

                while (pos != PosEnd){

                    if (j++ % 16 == 0)

                        cout << endl << "    ";

                    cout << hex << setw(4) << setfill('0') << pos << " ";

                    pos = BytePos[pos];

                }

                cout << endl;

            }

            cout << "buffer lists" << endl;

            for (i=PairListHigh; i>=0; i--){

                TUint16 index = PairLists[i];

                if (index == PosEnd)

                    continue;

                cout << dec;

                cout << "List " << i << endl;

                while (index != PosEnd){ 

                    char b0 = (char)PairBuffer[index].Pair;

                    char b1 = (char)(PairBuffer[index].Pair >> 8);

                    cout << "    " << setw(4) << setfill('0') << hex << PairBuffer[index].Pair << " " << "<" << (isgraph(b1)? b1:'.') << (isgraph(b0) ? b0 : '.') << ">";  

                    TUint16 pos;

                    pos = PairBuffer[index].Pos;

                    int k = 0;

                    while (pos != PosEnd){

                        if (k%16 ==0) {

                            cout << endl << "        ";

                        };

                        cout << setw(4) << setfill('0') << PairPos[pos].Pos << " ";

                        k ++;

                        pos = PairPos[pos].Next;

                    }

                    cout << endl;

                    index = PairBuffer[index].Next;

                }

            }

        }

#endif

	public:

        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