Home | History | Annotate | Download | only in C 
      1 /* LzFind.h -- Match finder for LZ algorithms
      2 2015-10-15 : 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   Byte streamEndWasReached;
     25   Byte btMode;
     26   Byte bigHash;
     27   Byte directInput;
     28 
     29   UInt32 matchMaxLen;
     30   CLzRef *hash;
     31   CLzRef *son;
     32   UInt32 hashMask;
     33   UInt32 cutValue;
     34 
     35   Byte *bufferBase;
     36   ISeqInStream *stream;
     37 
     38   UInt32 blockSize;
     39   UInt32 keepSizeBefore;
     40   UInt32 keepSizeAfter;
     41 
     42   UInt32 numHashBytes;
     43   size_t directInputRem;
     44   UInt32 historySize;
     45   UInt32 fixedHashSize;
     46   UInt32 hashSizeSum;
     47   SRes result;
     48   UInt32 crc[256];
     49   size_t numRefs;
     50 } CMatchFinder;
     51 
     52 #define Inline_MatchFinder_GetPointerToCurrentPos(p) ((p)->buffer)
     53 
     54 #define Inline_MatchFinder_GetNumAvailableBytes(p) ((p)->streamPos - (p)->pos)
     55 
     56 #define Inline_MatchFinder_IsFinishedOK(p) \
     57     ((p)->streamEndWasReached \
     58         && (p)->streamPos == (p)->pos \
     59         && (!(p)->directInput || (p)->directInputRem == 0))
     60 
     61 int MatchFinder_NeedMove(CMatchFinder *p);
     62 Byte *MatchFinder_GetPointerToCurrentPos(CMatchFinder *p);
     63 void MatchFinder_MoveBlock(CMatchFinder *p);
     64 void MatchFinder_ReadIfRequired(CMatchFinder *p);
     65 
     66 void MatchFinder_Construct(CMatchFinder *p);
     67 
     68 /* Conditions:
     69      historySize <= 3 GB
     70      keepAddBufferBefore + matchMaxLen + keepAddBufferAfter < 511MB
     71 */
     72 int MatchFinder_Create(CMatchFinder *p, UInt32 historySize,
     73     UInt32 keepAddBufferBefore, UInt32 matchMaxLen, UInt32 keepAddBufferAfter,
     74     ISzAlloc *alloc);
     75 void MatchFinder_Free(CMatchFinder *p, ISzAlloc *alloc);
     76 void MatchFinder_Normalize3(UInt32 subValue, CLzRef *items, size_t numItems);
     77 void MatchFinder_ReduceOffsets(CMatchFinder *p, UInt32 subValue);
     78 
     79 UInt32 * GetMatchesSpec1(UInt32 lenLimit, UInt32 curMatch, UInt32 pos, const Byte *buffer, CLzRef *son,
     80     UInt32 _cyclicBufferPos, UInt32 _cyclicBufferSize, UInt32 _cutValue,
     81     UInt32 *distances, UInt32 maxLen);
     82 
     83 /*
     84 Conditions:
     85   Mf_GetNumAvailableBytes_Func must be called before each Mf_GetMatchLen_Func.
     86   Mf_GetPointerToCurrentPos_Func's result must be used only before any other function
     87 */
     88 
     89 typedef void (*Mf_Init_Func)(void *object);
     90 typedef UInt32 (*Mf_GetNumAvailableBytes_Func)(void *object);
     91 typedef const Byte * (*Mf_GetPointerToCurrentPos_Func)(void *object);
     92 typedef UInt32 (*Mf_GetMatches_Func)(void *object, UInt32 *distances);
     93 typedef void (*Mf_Skip_Func)(void *object, UInt32);
     94 
     95 typedef struct _IMatchFinder
     96 {
     97   Mf_Init_Func Init;
     98   Mf_GetNumAvailableBytes_Func GetNumAvailableBytes;
     99   Mf_GetPointerToCurrentPos_Func GetPointerToCurrentPos;
    100   Mf_GetMatches_Func GetMatches;
    101   Mf_Skip_Func Skip;
    102 } IMatchFinder;
    103 
    104 void MatchFinder_CreateVTable(CMatchFinder *p, IMatchFinder *vTable);
    105 
    106 void MatchFinder_Init_2(CMatchFinder *p, int readData);
    107 void MatchFinder_Init(CMatchFinder *p);
    108 
    109 UInt32 Bt3Zip_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances);
    110 UInt32 Hc3Zip_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances);
    111 
    112 void Bt3Zip_MatchFinder_Skip(CMatchFinder *p, UInt32 num);
    113 void Hc3Zip_MatchFinder_Skip(CMatchFinder *p, UInt32 num);
    114 
    115 EXTERN_C_END
    116 
    117 #endif
    118