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1 /* LzFind.h -- Match finder for LZ algorithms
2 2021-07-13 : 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;  /* wrap over Zero is allowed (streamPos < pos). Use (UInt32)(streamPos - pos) */
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) ((const Byte *)(p)->buffer)
55 
56 #define Inline_MatchFinder_GetNumAvailableBytes(p) ((UInt32)((p)->streamPos - (p)->pos))
57 
58 /*
59 #define Inline_MatchFinder_IsFinishedOK(p) \
60     ((p)->streamEndWasReached \
61         && (p)->streamPos == (p)->pos \
62         && (!(p)->directInput || (p)->directInputRem == 0))
63 */
64 
65 int MatchFinder_NeedMove(CMatchFinder *p);
66 /* Byte *MatchFinder_GetPointerToCurrentPos(CMatchFinder *p); */
67 void MatchFinder_MoveBlock(CMatchFinder *p);
68 void MatchFinder_ReadIfRequired(CMatchFinder *p);
69 
70 void MatchFinder_Construct(CMatchFinder *p);
71 
72 /* Conditions:
73      historySize <= 3 GB
74      keepAddBufferBefore + matchMaxLen + keepAddBufferAfter < 511MB
75 */
76 int MatchFinder_Create(CMatchFinder *p, UInt32 historySize,
77     UInt32 keepAddBufferBefore, UInt32 matchMaxLen, UInt32 keepAddBufferAfter,
78     ISzAllocPtr alloc);
79 void MatchFinder_Free(CMatchFinder *p, ISzAllocPtr alloc);
80 void MatchFinder_Normalize3(UInt32 subValue, CLzRef *items, size_t numItems);
81 // void MatchFinder_ReduceOffsets(CMatchFinder *p, UInt32 subValue);
82 
83 /*
84 #define Inline_MatchFinder_InitPos(p, val) \
85     (p)->pos = (val); \
86     (p)->streamPos = (val);
87 */
88 
89 #define Inline_MatchFinder_ReduceOffsets(p, subValue) \
90     (p)->pos -= (subValue); \
91     (p)->streamPos -= (subValue);
92 
93 
94 UInt32 * GetMatchesSpec1(UInt32 lenLimit, UInt32 curMatch, UInt32 pos, const Byte *buffer, CLzRef *son,
95     size_t _cyclicBufferPos, UInt32 _cyclicBufferSize, UInt32 _cutValue,
96     UInt32 *distances, UInt32 maxLen);
97 
98 /*
99 Conditions:
100   Mf_GetNumAvailableBytes_Func must be called before each Mf_GetMatchLen_Func.
101   Mf_GetPointerToCurrentPos_Func's result must be used only before any other function
102 */
103 
104 typedef void (*Mf_Init_Func)(void *object);
105 typedef UInt32 (*Mf_GetNumAvailableBytes_Func)(void *object);
106 typedef const Byte * (*Mf_GetPointerToCurrentPos_Func)(void *object);
107 typedef UInt32 * (*Mf_GetMatches_Func)(void *object, UInt32 *distances);
108 typedef void (*Mf_Skip_Func)(void *object, UInt32);
109 
110 typedef struct _IMatchFinder
111 {
112   Mf_Init_Func Init;
113   Mf_GetNumAvailableBytes_Func GetNumAvailableBytes;
114   Mf_GetPointerToCurrentPos_Func GetPointerToCurrentPos;
115   Mf_GetMatches_Func GetMatches;
116   Mf_Skip_Func Skip;
117 } IMatchFinder2;
118 
119 void MatchFinder_CreateVTable(CMatchFinder *p, IMatchFinder2 *vTable);
120 
121 void MatchFinder_Init_LowHash(CMatchFinder *p);
122 void MatchFinder_Init_HighHash(CMatchFinder *p);
123 void MatchFinder_Init_4(CMatchFinder *p);
124 void MatchFinder_Init(CMatchFinder *p);
125 
126 UInt32* Bt3Zip_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances);
127 UInt32* Hc3Zip_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances);
128 
129 void Bt3Zip_MatchFinder_Skip(CMatchFinder *p, UInt32 num);
130 void Hc3Zip_MatchFinder_Skip(CMatchFinder *p, UInt32 num);
131 
132 void LzFindPrepare(void);
133 
134 EXTERN_C_END
135 
136 #endif
137