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      1 /* LzFind.h -- Match finder for LZ algorithms
      2 2013-01-18 : Igor Pavlov : Public domain */
      3 
      4 #ifndef __LZ_FIND_H
      5 #define __LZ_FIND_H
      6 
      7 #include "7zTypes.h"
      8 
      9 EXTERN_C_BEGIN
     10 
     11 typedef UInt32 CLzRef;
     12 
     13 typedef struct _CMatchFinder
     14 {
     15   Byte *buffer;
     16   UInt32 pos;
     17   UInt32 posLimit;
     18   UInt32 streamPos;
     19   UInt32 lenLimit;
     20 
     21   UInt32 cyclicBufferPos;
     22   UInt32 cyclicBufferSize; /* it must be = (historySize + 1) */
     23 
     24   UInt32 matchMaxLen;
     25   CLzRef *hash;
     26   CLzRef *son;
     27   UInt32 hashMask;
     28   UInt32 cutValue;
     29 
     30   Byte *bufferBase;
     31   ISeqInStream *stream;
     32   int streamEndWasReached;
     33 
     34   UInt32 blockSize;
     35   UInt32 keepSizeBefore;
     36   UInt32 keepSizeAfter;
     37 
     38   UInt32 numHashBytes;
     39   int directInput;
     40   size_t directInputRem;
     41   int btMode;
     42   int bigHash;
     43   UInt32 historySize;
     44   UInt32 fixedHashSize;
     45   UInt32 hashSizeSum;
     46   UInt32 numSons;
     47   SRes result;
     48   UInt32 crc[256];
     49 } CMatchFinder;
     50 
     51 #define Inline_MatchFinder_GetPointerToCurrentPos(p) ((p)->buffer)
     52 #define Inline_MatchFinder_GetIndexByte(p, index) ((p)->buffer[(Int32)(index)])
     53 
     54 #define Inline_MatchFinder_GetNumAvailableBytes(p) ((p)->streamPos - (p)->pos)
     55 
     56 int MatchFinder_NeedMove(CMatchFinder *p);
     57 Byte *MatchFinder_GetPointerToCurrentPos(CMatchFinder *p);
     58 void MatchFinder_MoveBlock(CMatchFinder *p);
     59 void MatchFinder_ReadIfRequired(CMatchFinder *p);
     60 
     61 void MatchFinder_Construct(CMatchFinder *p);
     62 
     63 /* Conditions:
     64      historySize <= 3 GB
     65      keepAddBufferBefore + matchMaxLen + keepAddBufferAfter < 511MB
     66 */
     67 int MatchFinder_Create(CMatchFinder *p, UInt32 historySize,
     68     UInt32 keepAddBufferBefore, UInt32 matchMaxLen, UInt32 keepAddBufferAfter,
     69     ISzAlloc *alloc);
     70 void MatchFinder_Free(CMatchFinder *p, ISzAlloc *alloc);
     71 void MatchFinder_Normalize3(UInt32 subValue, CLzRef *items, UInt32 numItems);
     72 void MatchFinder_ReduceOffsets(CMatchFinder *p, UInt32 subValue);
     73 
     74 UInt32 * GetMatchesSpec1(UInt32 lenLimit, UInt32 curMatch, UInt32 pos, const Byte *buffer, CLzRef *son,
     75     UInt32 _cyclicBufferPos, UInt32 _cyclicBufferSize, UInt32 _cutValue,
     76     UInt32 *distances, UInt32 maxLen);
     77 
     78 /*
     79 Conditions:
     80   Mf_GetNumAvailableBytes_Func must be called before each Mf_GetMatchLen_Func.
     81   Mf_GetPointerToCurrentPos_Func's result must be used only before any other function
     82 */
     83 
     84 typedef void (*Mf_Init_Func)(void *object);
     85 typedef Byte (*Mf_GetIndexByte_Func)(void *object, Int32 index);
     86 typedef UInt32 (*Mf_GetNumAvailableBytes_Func)(void *object);
     87 typedef const Byte * (*Mf_GetPointerToCurrentPos_Func)(void *object);
     88 typedef UInt32 (*Mf_GetMatches_Func)(void *object, UInt32 *distances);
     89 typedef void (*Mf_Skip_Func)(void *object, UInt32);
     90 
     91 typedef struct _IMatchFinder
     92 {
     93   Mf_Init_Func Init;
     94   Mf_GetIndexByte_Func GetIndexByte;
     95   Mf_GetNumAvailableBytes_Func GetNumAvailableBytes;
     96   Mf_GetPointerToCurrentPos_Func GetPointerToCurrentPos;
     97   Mf_GetMatches_Func GetMatches;
     98   Mf_Skip_Func Skip;
     99 } IMatchFinder;
    100 
    101 void MatchFinder_CreateVTable(CMatchFinder *p, IMatchFinder *vTable);
    102 
    103 void MatchFinder_Init(CMatchFinder *p);
    104 UInt32 Bt3Zip_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances);
    105 UInt32 Hc3Zip_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances);
    106 void Bt3Zip_MatchFinder_Skip(CMatchFinder *p, UInt32 num);
    107 void Hc3Zip_MatchFinder_Skip(CMatchFinder *p, UInt32 num);
    108 
    109 EXTERN_C_END
    110 
    111 #endif
    112