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1 /* LzFind.h -- Match finder for LZ algorithms
2 2017-06-10 : 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 
51   UInt64 expectedDataSize;
52 } CMatchFinder;
53 
54 #define Inline_MatchFinder_GetPointerToCurrentPos(p) ((p)->buffer)
55 
56 #define Inline_MatchFinder_GetNumAvailableBytes(p) ((p)->streamPos - (p)->pos)
57 
58 #define Inline_MatchFinder_IsFinishedOK(p) \
59     ((p)->streamEndWasReached \
60         && (p)->streamPos == (p)->pos \
61         && (!(p)->directInput || (p)->directInputRem == 0))
62 
63 int MatchFinder_NeedMove(CMatchFinder *p);
64 Byte *MatchFinder_GetPointerToCurrentPos(CMatchFinder *p);
65 void MatchFinder_MoveBlock(CMatchFinder *p);
66 void MatchFinder_ReadIfRequired(CMatchFinder *p);
67 
68 void MatchFinder_Construct(CMatchFinder *p);
69 
70 /* Conditions:
71      historySize <= 3 GB
72      keepAddBufferBefore + matchMaxLen + keepAddBufferAfter < 511MB
73 */
74 int MatchFinder_Create(CMatchFinder *p, UInt32 historySize,
75     UInt32 keepAddBufferBefore, UInt32 matchMaxLen, UInt32 keepAddBufferAfter,
76     ISzAllocPtr alloc);
77 void MatchFinder_Free(CMatchFinder *p, ISzAllocPtr alloc);
78 void MatchFinder_Normalize3(UInt32 subValue, CLzRef *items, size_t numItems);
79 void MatchFinder_ReduceOffsets(CMatchFinder *p, UInt32 subValue);
80 
81 UInt32 * GetMatchesSpec1(UInt32 lenLimit, UInt32 curMatch, UInt32 pos, const Byte *buffer, CLzRef *son,
82     UInt32 _cyclicBufferPos, UInt32 _cyclicBufferSize, UInt32 _cutValue,
83     UInt32 *distances, UInt32 maxLen);
84 
85 /*
86 Conditions:
87   Mf_GetNumAvailableBytes_Func must be called before each Mf_GetMatchLen_Func.
88   Mf_GetPointerToCurrentPos_Func's result must be used only before any other function
89 */
90 
91 typedef void (*Mf_Init_Func)(void *object);
92 typedef UInt32 (*Mf_GetNumAvailableBytes_Func)(void *object);
93 typedef const Byte * (*Mf_GetPointerToCurrentPos_Func)(void *object);
94 typedef UInt32 (*Mf_GetMatches_Func)(void *object, UInt32 *distances);
95 typedef void (*Mf_Skip_Func)(void *object, UInt32);
96 
97 typedef struct _IMatchFinder
98 {
99   Mf_Init_Func Init;
100   Mf_GetNumAvailableBytes_Func GetNumAvailableBytes;
101   Mf_GetPointerToCurrentPos_Func GetPointerToCurrentPos;
102   Mf_GetMatches_Func GetMatches;
103   Mf_Skip_Func Skip;
104 } IMatchFinder;
105 
106 void MatchFinder_CreateVTable(CMatchFinder *p, IMatchFinder *vTable);
107 
108 void MatchFinder_Init_LowHash(CMatchFinder *p);
109 void MatchFinder_Init_HighHash(CMatchFinder *p);
110 void MatchFinder_Init_3(CMatchFinder *p, int readData);
111 void MatchFinder_Init(CMatchFinder *p);
112 
113 UInt32 Bt3Zip_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances);
114 UInt32 Hc3Zip_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances);
115 
116 void Bt3Zip_MatchFinder_Skip(CMatchFinder *p, UInt32 num);
117 void Hc3Zip_MatchFinder_Skip(CMatchFinder *p, UInt32 num);
118 
119 EXTERN_C_END
120 
121 #endif
122