LzHash.h

/* LzHash.h -- HASH functions for LZ algorithms
2015-04-12 : Igor Pavlov : Public domain */
 
#ifndef __LZ_HASH_H
#define __LZ_HASH_H
 
#define kHash2Size  (1 << 10)
#define kHash3Size  (1 << 16)
#define kHash4Size  (1 << 20)
 
#define kFix3HashSize  (kHash2Size)
#define kFix4HashSize  (kHash2Size + kHash3Size)
#define kFix5HashSize  (kHash2Size + kHash3Size + kHash4Size)
 
#define HASH2_CALC  hv = cur[0] | ((UInt32)cur[1] << 8);
 
#define HASH3_CALC  {\
  UInt32 temp = p->crc[cur[0]] ^ cur[1]; \
  h2 = temp & (kHash2Size - 1); \
  hv = (temp ^ ((UInt32)cur[2] << 8)) & p->hashMask; }
 
#define HASH4_CALC  {\
  UInt32 temp = p->crc[cur[0]] ^ cur[1]; \
  h2 = temp & (kHash2Size - 1); \
  temp ^= ((UInt32)cur[2] << 8); \
  h3 = temp & (kHash3Size - 1); \
  hv = (temp ^ (p->crc[cur[3]] << 5)) & p->hashMask; }
 
#define HASH5_CALC  {\
  UInt32 temp = p->crc[cur[0]] ^ cur[1]; \
  h2 = temp & (kHash2Size - 1); \
  temp ^= ((UInt32)cur[2] << 8); \
  h3 = temp & (kHash3Size - 1); \
  temp ^= (p->crc[cur[3]] << 5); \
  h4 = temp & (kHash4Size - 1); \
  hv = (temp ^ (p->crc[cur[4]] << 3)) & p->hashMask; }
 
/* #define HASH_ZIP_CALC hv = ((cur[0] | ((UInt32)cur[1] << 8)) ^ p->crc[cur[2]]) & 0xFFFF; */
#define HASH_ZIP_CALC  hv = ((cur[2] | ((UInt32)cur[0] << 8)) ^ p->crc[cur[1]]) & 0xFFFF;
 
#define MT_HASH2_CALC \
  h2 = (p->crc[cur[0]] ^ cur[1]) & (kHash2Size - 1);
 
#define MT_HASH3_CALC  {\
  UInt32 temp = p->crc[cur[0]] ^ cur[1]; \
  h2 = temp & (kHash2Size - 1); \
  h3 = (temp ^ ((UInt32)cur[2] << 8)) & (kHash3Size - 1); }
 
#define MT_HASH4_CALC  {\
  UInt32 temp = p->crc[cur[0]] ^ cur[1]; \
  h2 = temp & (kHash2Size - 1); \
  temp ^= ((UInt32)cur[2] << 8); \
  h3 = temp & (kHash3Size - 1); \
  h4 = (temp ^ (p->crc[cur[3]] << 5)) & (kHash4Size - 1); }
 
#endif