/* LzFind.h -- Match finder for LZ algorithms
2015-10-15 : Igor Pavlov : Public domain */

#ifndef __LZ_FIND_H
#define __LZ_FIND_H

#include "7zTypes.h"

EXTERN_C_BEGIN

typedef UInt32 CLzRef;

typedef struct _CMatchFinder
{
    Byte* buffer;
    UInt32 pos;
    UInt32 posLimit;
    UInt32 streamPos;
    UInt32 lenLimit;

    UInt32 cyclicBufferPos;
    UInt32 cyclicBufferSize; /* it must be = (historySize + 1) */

    Byte streamEndWasReached;
    Byte btMode;
    Byte bigHash;
    Byte directInput;

    UInt32 matchMaxLen;
    CLzRef* hash;
    CLzRef* son;
    UInt32 hashMask;
    UInt32 cutValue;

    Byte* bufferBase;
    ISeqInStream* stream;

    UInt32 blockSize;
    UInt32 keepSizeBefore;
    UInt32 keepSizeAfter;

    UInt32 numHashBytes;
    size_t directInputRem;
    UInt32 historySize;
    UInt32 fixedHashSize;
    UInt32 hashSizeSum;
    SRes result;
    UInt32 crc[256];
    size_t numRefs;
} CMatchFinder;

#define Inline_MatchFinder_GetPointerToCurrentPos(p) ((p)->buffer)

#define Inline_MatchFinder_GetNumAvailableBytes(p) ((p)->streamPos - (p)->pos)

#define Inline_MatchFinder_IsFinishedOK(p) \
    ((p)->streamEndWasReached \
        && (p)->streamPos == (p)->pos \
        && (!(p)->directInput || (p)->directInputRem == 0))

int MatchFinder_NeedMove(CMatchFinder* p);
Byte* MatchFinder_GetPointerToCurrentPos(CMatchFinder* p);
void MatchFinder_MoveBlock(CMatchFinder* p);
void MatchFinder_ReadIfRequired(CMatchFinder* p);

void MatchFinder_Construct(CMatchFinder* p);

/* Conditions:
     historySize <= 3 GB
     keepAddBufferBefore + matchMaxLen + keepAddBufferAfter < 511MB
*/
int MatchFinder_Create(CMatchFinder* p, UInt32 historySize,
    UInt32 keepAddBufferBefore, UInt32 matchMaxLen, UInt32 keepAddBufferAfter,
    ISzAlloc* alloc);
void MatchFinder_Free(CMatchFinder* p, ISzAlloc* alloc);
void MatchFinder_Normalize3(UInt32 subValue, CLzRef* items, size_t numItems);
void MatchFinder_ReduceOffsets(CMatchFinder* p, UInt32 subValue);

UInt32* GetMatchesSpec1(UInt32 lenLimit, UInt32 curMatch, UInt32 pos, const Byte* buffer, CLzRef* son,
    UInt32 _cyclicBufferPos, UInt32 _cyclicBufferSize, UInt32 _cutValue,
    UInt32* distances, UInt32 maxLen);

/*
Conditions:
  Mf_GetNumAvailableBytes_Func must be called before each Mf_GetMatchLen_Func.
  Mf_GetPointerToCurrentPos_Func's result must be used only before any other function
*/

typedef void (*Mf_Init_Func)(void* object);
typedef UInt32(*Mf_GetNumAvailableBytes_Func)(void* object);
typedef const Byte* (*Mf_GetPointerToCurrentPos_Func)(void* object);
typedef UInt32(*Mf_GetMatches_Func)(void* object, UInt32* distances);
typedef void (*Mf_Skip_Func)(void* object, UInt32);

typedef struct _IMatchFinder
{
    Mf_Init_Func Init;
    Mf_GetNumAvailableBytes_Func GetNumAvailableBytes;
    Mf_GetPointerToCurrentPos_Func GetPointerToCurrentPos;
    Mf_GetMatches_Func GetMatches;
    Mf_Skip_Func Skip;
} IMatchFinder;

void MatchFinder_CreateVTable(CMatchFinder* p, IMatchFinder* vTable);

void MatchFinder_Init_2(CMatchFinder* p, int readData);
void MatchFinder_Init(CMatchFinder* p);

UInt32 Bt3Zip_MatchFinder_GetMatches(CMatchFinder* p, UInt32* distances);
UInt32 Hc3Zip_MatchFinder_GetMatches(CMatchFinder* p, UInt32* distances);

void Bt3Zip_MatchFinder_Skip(CMatchFinder* p, UInt32 num);
void Hc3Zip_MatchFinder_Skip(CMatchFinder* p, UInt32 num);

EXTERN_C_END

#endif
