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