nel/3rdparty/seven_zip/LzHash.h

   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