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author | 2023-05-04 02:41:16 +1000 | |
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committer | 2023-05-04 02:41:16 +1000 | |
commit | a504bde3a7462b54fafd5cfc2f52e58d0f3218e1 (patch) | |
tree | 8b3108d572b1a0873a6cdbb4e8af1f17179545c3 /3rdparty/lzma/C/LzHash.h | |
parent | befb9bf4a8cfdb2b693a32e32535b5eac522c5d8 (diff) |
3rdparty/lzma: Updated to LZMA SDK version 22.01
Diffstat (limited to '3rdparty/lzma/C/LzHash.h')
-rw-r--r-- | 3rdparty/lzma/C/LzHash.h | 67 |
1 files changed, 22 insertions, 45 deletions
diff --git a/3rdparty/lzma/C/LzHash.h b/3rdparty/lzma/C/LzHash.h index e7c942303dd..77b898cfab5 100644 --- a/3rdparty/lzma/C/LzHash.h +++ b/3rdparty/lzma/C/LzHash.h @@ -1,57 +1,34 @@ /* LzHash.h -- HASH functions for LZ algorithms -2015-04-12 : Igor Pavlov : Public domain */ +2019-10-30 : Igor Pavlov : Public domain */ #ifndef __LZ_HASH_H #define __LZ_HASH_H +/* + (kHash2Size >= (1 << 8)) : Required + (kHash3Size >= (1 << 16)) : Required +*/ + #define kHash2Size (1 << 10) #define kHash3Size (1 << 16) -#define kHash4Size (1 << 20) +// #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); } +// #define kFix5HashSize (kHash2Size + kHash3Size + kHash4Size) + +/* + We use up to 3 crc values for hash: + crc0 + crc1 << Shift_1 + crc2 << Shift_2 + (Shift_1 = 5) and (Shift_2 = 10) is good tradeoff. + Small values for Shift are not good for collision rate. + Big value for Shift_2 increases the minimum size + of hash table, that will be slow for small files. +*/ + +#define kLzHash_CrcShift_1 5 +#define kLzHash_CrcShift_2 10 #endif |