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