LzFind.h

/* LzFind.h -- Match finder for LZ algorithms
2024-01-22 : Igor Pavlov : Public domain */

#ifndef ZIP7_INC_LZ_FIND_H
#define ZIP7_INC_LZ_FIND_H

#include "7zTypes.h"

EXTERN_C_BEGIN

typedef UInt32 CLzRef;

typedef struct
{
  const Byte *buffer;
  UInt32 pos;
  UInt32 posLimit;
  UInt32 streamPos;  /* wrap over Zero is allowed (streamPos < pos). Use (UInt32)(streamPos - pos) */
  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 *bufBase;
  ISeqInStreamPtr stream;
  
  UInt32 blockSize;
  UInt32 keepSizeBefore;
  UInt32 keepSizeAfter;

  UInt32 numHashBytes;
  size_t directInputRem;
  UInt32 historySize;
  UInt32 fixedHashSize;
  Byte numHashBytes_Min;
  Byte numHashOutBits;
  Byte _pad2_[2];
  SRes result;
  UInt32 crc[256];
  size_t numRefs;

  UInt64 expectedDataSize;
} CMatchFinder;

#define Inline_MatchFinder_GetPointerToCurrentPos(p) ((const Byte *)(p)->buffer)

#define Inline_MatchFinder_GetNumAvailableBytes(p) ((UInt32)((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);

/* (directInput = 0) is default value.
   It's required to provide correct (directInput) value
   before calling MatchFinder_Create().
   You can set (directInput) by any of the following calls:
     - MatchFinder_SET_DIRECT_INPUT_BUF()
     - MatchFinder_SET_STREAM()
     - MatchFinder_SET_STREAM_MODE()
*/

#define MatchFinder_SET_DIRECT_INPUT_BUF(p, _src_, _srcLen_) { \
  (p)->stream = NULL; \
  (p)->directInput = 1; \
  (p)->buffer = (_src_); \
  (p)->directInputRem = (_srcLen_); }

/*
#define MatchFinder_SET_STREAM_MODE(p) { \
  (p)->directInput = 0; }
*/

#define MatchFinder_SET_STREAM(p, _stream_) { \
  (p)->stream = _stream_; \
  (p)->directInput = 0; }
  

int MatchFinder_Create(CMatchFinder *p, UInt32 historySize,
    UInt32 keepAddBufferBefore, UInt32 matchMaxLen, UInt32 keepAddBufferAfter,
    ISzAllocPtr alloc);
void MatchFinder_Free(CMatchFinder *p, ISzAllocPtr alloc);
void MatchFinder_Normalize3(UInt32 subValue, CLzRef *items, size_t numItems);

/*
#define MatchFinder_INIT_POS(p, val) \
    (p)->pos = (val); \
    (p)->streamPos = (val);
*/

// void MatchFinder_ReduceOffsets(CMatchFinder *p, UInt32 subValue);
#define MatchFinder_REDUCE_OFFSETS(p, subValue) \
    (p)->pos -= (subValue); \
    (p)->streamPos -= (subValue);


UInt32 * GetMatchesSpec1(UInt32 lenLimit, UInt32 curMatch, UInt32 pos, const Byte *buffer, CLzRef *son,
    size_t _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
{
  Mf_Init_Func Init;
  Mf_GetNumAvailableBytes_Func GetNumAvailableBytes;
  Mf_GetPointerToCurrentPos_Func GetPointerToCurrentPos;
  Mf_GetMatches_Func GetMatches;
  Mf_Skip_Func Skip;
} IMatchFinder2;

void MatchFinder_CreateVTable(CMatchFinder *p, IMatchFinder2 *vTable);

void MatchFinder_Init_LowHash(CMatchFinder *p);
void MatchFinder_Init_HighHash(CMatchFinder *p);
void MatchFinder_Init_4(CMatchFinder *p);
// void MatchFinder_Init(CMatchFinder *p);
void MatchFinder_Init(void *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);

void LzFindPrepare(void);

EXTERN_C_END

#endif