35 lines
847 B
C
35 lines
847 B
C
/* LzHash.h -- HASH constants for LZ algorithms
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2023-03-05 : Igor Pavlov : Public domain */
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#ifndef ZIP7_INC_LZ_HASH_H
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#define ZIP7_INC_LZ_HASH_H
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/*
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(kHash2Size >= (1 << 8)) : Required
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(kHash3Size >= (1 << 16)) : Required
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*/
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#define kHash2Size (1 << 10)
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#define kHash3Size (1 << 16)
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// #define kHash4Size (1 << 20)
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#define kFix3HashSize (kHash2Size)
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#define kFix4HashSize (kHash2Size + kHash3Size)
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// #define kFix5HashSize (kHash2Size + kHash3Size + kHash4Size)
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/*
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We use up to 3 crc values for hash:
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crc0
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crc1 << Shift_1
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crc2 << Shift_2
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(Shift_1 = 5) and (Shift_2 = 10) is good tradeoff.
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Small values for Shift are not good for collision rate.
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Big value for Shift_2 increases the minimum size
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of hash table, that will be slow for small files.
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*/
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#define kLzHash_CrcShift_1 5
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#define kLzHash_CrcShift_2 10
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#endif
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