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1 /* LzHash.h -- HASH functions for LZ algorithms
2 2015-04-12 : Igor Pavlov : Public domain */
3 
4 #ifndef __LZ_HASH_H
5 #define __LZ_HASH_H
6 
7 #define kHash2Size (1 << 10)
8 #define kHash3Size (1 << 16)
9 #define kHash4Size (1 << 20)
10 
11 #define kFix3HashSize (kHash2Size)
12 #define kFix4HashSize (kHash2Size + kHash3Size)
13 #define kFix5HashSize (kHash2Size + kHash3Size + kHash4Size)
14 
15 #define HASH2_CALC hv = cur[0] | ((UInt32)cur[1] << 8);
16 
17 #define HASH3_CALC { \
18   UInt32 temp = p->crc[cur[0]] ^ cur[1]; \
19   h2 = temp & (kHash2Size - 1); \
20   hv = (temp ^ ((UInt32)cur[2] << 8)) & p->hashMask; }
21 
22 #define HASH4_CALC { \
23   UInt32 temp = p->crc[cur[0]] ^ cur[1]; \
24   h2 = temp & (kHash2Size - 1); \
25   temp ^= ((UInt32)cur[2] << 8); \
26   h3 = temp & (kHash3Size - 1); \
27   hv = (temp ^ (p->crc[cur[3]] << 5)) & p->hashMask; }
28 
29 #define HASH5_CALC { \
30   UInt32 temp = p->crc[cur[0]] ^ cur[1]; \
31   h2 = temp & (kHash2Size - 1); \
32   temp ^= ((UInt32)cur[2] << 8); \
33   h3 = temp & (kHash3Size - 1); \
34   temp ^= (p->crc[cur[3]] << 5); \
35   h4 = temp & (kHash4Size - 1); \
36   hv = (temp ^ (p->crc[cur[4]] << 3)) & p->hashMask; }
37 
38 /* #define HASH_ZIP_CALC hv = ((cur[0] | ((UInt32)cur[1] << 8)) ^ p->crc[cur[2]]) & 0xFFFF; */
39 #define HASH_ZIP_CALC hv = ((cur[2] | ((UInt32)cur[0] << 8)) ^ p->crc[cur[1]]) & 0xFFFF;
40 
41 
42 #define MT_HASH2_CALC \
43   h2 = (p->crc[cur[0]] ^ cur[1]) & (kHash2Size - 1);
44 
45 #define MT_HASH3_CALC { \
46   UInt32 temp = p->crc[cur[0]] ^ cur[1]; \
47   h2 = temp & (kHash2Size - 1); \
48   h3 = (temp ^ ((UInt32)cur[2] << 8)) & (kHash3Size - 1); }
49 
50 #define MT_HASH4_CALC { \
51   UInt32 temp = p->crc[cur[0]] ^ cur[1]; \
52   h2 = temp & (kHash2Size - 1); \
53   temp ^= ((UInt32)cur[2] << 8); \
54   h3 = temp & (kHash3Size - 1); \
55   h4 = (temp ^ (p->crc[cur[3]] << 5)) & (kHash4Size - 1); }
56 
57 #endif
58