xref: /illumos-gate/usr/src/common/lzma/LzHash.h (revision b1efbcd6)
1 /* LzHash.h -- HASH functions for LZ algorithms
2 2008-10-04 : Igor Pavlov : Public domain */
3 
4 #ifndef __LZHASH_H
5 #define __LZHASH_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 hashValue = cur[0] | ((UInt32)cur[1] << 8);
16 
17 #define HASH3_CALC { \
18   UInt32 temp = p->crc[cur[0]] ^ cur[1]; \
19   hash2Value = temp & (kHash2Size - 1); \
20   hashValue = (temp ^ ((UInt32)cur[2] << 8)) & p->hashMask; }
21 
22 #define HASH4_CALC { \
23   UInt32 temp = p->crc[cur[0]] ^ cur[1]; \
24   hash2Value = temp & (kHash2Size - 1); \
25   hash3Value = (temp ^ ((UInt32)cur[2] << 8)) & (kHash3Size - 1); \
26   hashValue = (temp ^ ((UInt32)cur[2] << 8) ^ (p->crc[cur[3]] << 5)) & p->hashMask; }
27 
28 #define HASH5_CALC { \
29   UInt32 temp = p->crc[cur[0]] ^ cur[1]; \
30   hash2Value = temp & (kHash2Size - 1); \
31   hash3Value = (temp ^ ((UInt32)cur[2] << 8)) & (kHash3Size - 1); \
32   hash4Value = (temp ^ ((UInt32)cur[2] << 8) ^ (p->crc[cur[3]] << 5)); \
33   hashValue = (hash4Value ^ (p->crc[cur[4]] << 3)) & p->hashMask; \
34   hash4Value &= (kHash4Size - 1); }
35 
36 /* #define HASH_ZIP_CALC hashValue = ((cur[0] | ((UInt32)cur[1] << 8)) ^ p->crc[cur[2]]) & 0xFFFF; */
37 #define HASH_ZIP_CALC hashValue = ((cur[2] | ((UInt32)cur[0] << 8)) ^ p->crc[cur[1]]) & 0xFFFF;
38 
39 
40 #define MT_HASH2_CALC \
41   hash2Value = (p->crc[cur[0]] ^ cur[1]) & (kHash2Size - 1);
42 
43 #define MT_HASH3_CALC { \
44   UInt32 temp = p->crc[cur[0]] ^ cur[1]; \
45   hash2Value = temp & (kHash2Size - 1); \
46   hash3Value = (temp ^ ((UInt32)cur[2] << 8)) & (kHash3Size - 1); }
47 
48 #define MT_HASH4_CALC { \
49   UInt32 temp = p->crc[cur[0]] ^ cur[1]; \
50   hash2Value = temp & (kHash2Size - 1); \
51   hash3Value = (temp ^ ((UInt32)cur[2] << 8)) & (kHash3Size - 1); \
52   hash4Value = (temp ^ ((UInt32)cur[2] << 8) ^ (p->crc[cur[3]] << 5)) & (kHash4Size - 1); }
53 
54 #endif
55