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1 /* LzFind.h -- Match finder for LZ algorithms
2 2023-03-04 : Igor Pavlov : Public domain */
3 
4 #ifndef ZIP7_INC_LZ_FIND_H
5 #define ZIP7_INC_LZ_FIND_H
6 
7 #include "7zTypes.h"
8 
9 EXTERN_C_BEGIN
10 
11 typedef UInt32 CLzRef;
12 
13 typedef struct
14 {
15   const 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 *bufBase;
36   ISeqInStreamPtr 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   Byte numHashBytes_Min;
47   Byte numHashOutBits;
48   Byte _pad2_[2];
49   SRes result;
50   UInt32 crc[256];
51   size_t numRefs;
52 
53   UInt64 expectedDataSize;
54 } CMatchFinder;
55 
56 #define Inline_MatchFinder_GetPointerToCurrentPos(p) ((const Byte *)(p)->buffer)
57 
58 #define Inline_MatchFinder_GetNumAvailableBytes(p) ((UInt32)((p)->streamPos - (p)->pos))
59 
60 /*
61 #define Inline_MatchFinder_IsFinishedOK(p) \
62     ((p)->streamEndWasReached \
63         && (p)->streamPos == (p)->pos \
64         && (!(p)->directInput || (p)->directInputRem == 0))
65 */
66 
67 int MatchFinder_NeedMove(CMatchFinder *p);
68 /* Byte *MatchFinder_GetPointerToCurrentPos(CMatchFinder *p); */
69 void MatchFinder_MoveBlock(CMatchFinder *p);
70 void MatchFinder_ReadIfRequired(CMatchFinder *p);
71 
72 void MatchFinder_Construct(CMatchFinder *p);
73 
74 /* (directInput = 0) is default value.
75    It's required to provide correct (directInput) value
76    before calling MatchFinder_Create().
77    You can set (directInput) by any of the following calls:
78      - MatchFinder_SET_DIRECT_INPUT_BUF()
79      - MatchFinder_SET_STREAM()
80      - MatchFinder_SET_STREAM_MODE()
81 */
82 
83 #define MatchFinder_SET_DIRECT_INPUT_BUF(p, _src_, _srcLen_) { \
84   (p)->stream = NULL; \
85   (p)->directInput = 1; \
86   (p)->buffer = (_src_); \
87   (p)->directInputRem = (_srcLen_); }
88 
89 /*
90 #define MatchFinder_SET_STREAM_MODE(p) { \
91   (p)->directInput = 0; }
92 */
93 
94 #define MatchFinder_SET_STREAM(p, _stream_) { \
95   (p)->stream = _stream_; \
96   (p)->directInput = 0; }
97 
98 
99 int MatchFinder_Create(CMatchFinder *p, UInt32 historySize,
100     UInt32 keepAddBufferBefore, UInt32 matchMaxLen, UInt32 keepAddBufferAfter,
101     ISzAllocPtr alloc);
102 void MatchFinder_Free(CMatchFinder *p, ISzAllocPtr alloc);
103 void MatchFinder_Normalize3(UInt32 subValue, CLzRef *items, size_t numItems);
104 
105 /*
106 #define MatchFinder_INIT_POS(p, val) \
107     (p)->pos = (val); \
108     (p)->streamPos = (val);
109 */
110 
111 // void MatchFinder_ReduceOffsets(CMatchFinder *p, UInt32 subValue);
112 #define MatchFinder_REDUCE_OFFSETS(p, subValue) \
113     (p)->pos -= (subValue); \
114     (p)->streamPos -= (subValue);
115 
116 
117 UInt32 * GetMatchesSpec1(UInt32 lenLimit, UInt32 curMatch, UInt32 pos, const Byte *buffer, CLzRef *son,
118     size_t _cyclicBufferPos, UInt32 _cyclicBufferSize, UInt32 _cutValue,
119     UInt32 *distances, UInt32 maxLen);
120 
121 /*
122 Conditions:
123   Mf_GetNumAvailableBytes_Func must be called before each Mf_GetMatchLen_Func.
124   Mf_GetPointerToCurrentPos_Func's result must be used only before any other function
125 */
126 
127 typedef void (*Mf_Init_Func)(void *object);
128 typedef UInt32 (*Mf_GetNumAvailableBytes_Func)(void *object);
129 typedef const Byte * (*Mf_GetPointerToCurrentPos_Func)(void *object);
130 typedef UInt32 * (*Mf_GetMatches_Func)(void *object, UInt32 *distances);
131 typedef void (*Mf_Skip_Func)(void *object, UInt32);
132 
133 typedef struct
134 {
135   Mf_Init_Func Init;
136   Mf_GetNumAvailableBytes_Func GetNumAvailableBytes;
137   Mf_GetPointerToCurrentPos_Func GetPointerToCurrentPos;
138   Mf_GetMatches_Func GetMatches;
139   Mf_Skip_Func Skip;
140 } IMatchFinder2;
141 
142 void MatchFinder_CreateVTable(CMatchFinder *p, IMatchFinder2 *vTable);
143 
144 void MatchFinder_Init_LowHash(CMatchFinder *p);
145 void MatchFinder_Init_HighHash(CMatchFinder *p);
146 void MatchFinder_Init_4(CMatchFinder *p);
147 void MatchFinder_Init(CMatchFinder *p);
148 
149 UInt32* Bt3Zip_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances);
150 UInt32* Hc3Zip_MatchFinder_GetMatches(CMatchFinder *p, UInt32 *distances);
151 
152 void Bt3Zip_MatchFinder_Skip(CMatchFinder *p, UInt32 num);
153 void Hc3Zip_MatchFinder_Skip(CMatchFinder *p, UInt32 num);
154 
155 void LzFindPrepare(void);
156 
157 EXTERN_C_END
158 
159 #endif
160