| bashi@chromium.org | c2a9375 | 2012-05-02 00:18:22 +0000 | [diff] [blame] | 1 | /* LzHash.h -- HASH functions for LZ algorithms |
| agl@chromium.org | 92ae161 | 2012-06-26 19:58:38 +0000 | [diff] [blame] | 2 | 2009-02-07 : Igor Pavlov : Public domain |
| 3 | in the public domain */ |
| bashi@chromium.org | c2a9375 | 2012-05-02 00:18:22 +0000 | [diff] [blame] | 4 | |
| 5 | #ifndef __LZ_HASH_H |
| 6 | #define __LZ_HASH_H |
| 7 | |
| 8 | #define kHash2Size (1 << 10) |
| 9 | #define kHash3Size (1 << 16) |
| 10 | #define kHash4Size (1 << 20) |
| 11 | |
| 12 | #define kFix3HashSize (kHash2Size) |
| 13 | #define kFix4HashSize (kHash2Size + kHash3Size) |
| 14 | #define kFix5HashSize (kHash2Size + kHash3Size + kHash4Size) |
| 15 | |
| 16 | #define HASH2_CALC hashValue = cur[0] | ((UInt32)cur[1] << 8); |
| 17 | |
| 18 | #define HASH3_CALC { \ |
| 19 | UInt32 temp = p->crc[cur[0]] ^ cur[1]; \ |
| 20 | hash2Value = temp & (kHash2Size - 1); \ |
| 21 | hashValue = (temp ^ ((UInt32)cur[2] << 8)) & p->hashMask; } |
| 22 | |
| 23 | #define HASH4_CALC { \ |
| 24 | UInt32 temp = p->crc[cur[0]] ^ cur[1]; \ |
| 25 | hash2Value = temp & (kHash2Size - 1); \ |
| 26 | hash3Value = (temp ^ ((UInt32)cur[2] << 8)) & (kHash3Size - 1); \ |
| 27 | hashValue = (temp ^ ((UInt32)cur[2] << 8) ^ (p->crc[cur[3]] << 5)) & p->hashMask; } |
| 28 | |
| 29 | #define HASH5_CALC { \ |
| 30 | UInt32 temp = p->crc[cur[0]] ^ cur[1]; \ |
| 31 | hash2Value = temp & (kHash2Size - 1); \ |
| 32 | hash3Value = (temp ^ ((UInt32)cur[2] << 8)) & (kHash3Size - 1); \ |
| 33 | hash4Value = (temp ^ ((UInt32)cur[2] << 8) ^ (p->crc[cur[3]] << 5)); \ |
| 34 | hashValue = (hash4Value ^ (p->crc[cur[4]] << 3)) & p->hashMask; \ |
| 35 | hash4Value &= (kHash4Size - 1); } |
| 36 | |
| 37 | /* #define HASH_ZIP_CALC hashValue = ((cur[0] | ((UInt32)cur[1] << 8)) ^ p->crc[cur[2]]) & 0xFFFF; */ |
| 38 | #define HASH_ZIP_CALC hashValue = ((cur[2] | ((UInt32)cur[0] << 8)) ^ p->crc[cur[1]]) & 0xFFFF; |
| 39 | |
| 40 | |
| 41 | #define MT_HASH2_CALC \ |
| 42 | hash2Value = (p->crc[cur[0]] ^ cur[1]) & (kHash2Size - 1); |
| 43 | |
| 44 | #define MT_HASH3_CALC { \ |
| 45 | UInt32 temp = p->crc[cur[0]] ^ cur[1]; \ |
| 46 | hash2Value = temp & (kHash2Size - 1); \ |
| 47 | hash3Value = (temp ^ ((UInt32)cur[2] << 8)) & (kHash3Size - 1); } |
| 48 | |
| 49 | #define MT_HASH4_CALC { \ |
| 50 | UInt32 temp = p->crc[cur[0]] ^ cur[1]; \ |
| 51 | hash2Value = temp & (kHash2Size - 1); \ |
| 52 | hash3Value = (temp ^ ((UInt32)cur[2] << 8)) & (kHash3Size - 1); \ |
| 53 | hash4Value = (temp ^ ((UInt32)cur[2] << 8) ^ (p->crc[cur[3]] << 5)) & (kHash4Size - 1); } |
| 54 | |
| 55 | #endif |