1 | /**************************************************************************
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2 | *
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3 | * hash.h -- Hash function
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4 | * Copyright (C) 1994 Neil Sharman
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5 | *
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6 | * This program is free software; you can redistribute it and/or modify
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7 | * it under the terms of the GNU General Public License as published by
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8 | * the Free Software Foundation; either version 2 of the License, or
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9 | * (at your option) any later version.
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10 | *
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11 | * This program is distributed in the hope that it will be useful,
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12 | * but WITHOUT ANY WARRANTY; without even the implied warranty of
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13 | * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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14 | * GNU General Public License for more details.
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15 | *
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16 | * You should have received a copy of the GNU General Public License
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17 | * along with this program; if not, write to the Free Software
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18 | * Foundation, Inc., 675 Mass Ave, Cambridge, MA 02139, USA.
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19 | *
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20 | **************************************************************************/
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21 |
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22 | #ifndef H_HASH
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23 | #define H_HASH
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24 |
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25 | #define HASH(h, step, wd, tablesize) \
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26 | do { \
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27 | register u_char *p=wd; \
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28 | register long len = *p++; \
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29 | register unsigned long hval; \
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30 | if (len>25) len = 25; \
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31 | for (hval=0; len; --len) \
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32 | hval = (hval << 5) - hval + *p++; \
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33 | step = hval % (tablesize - 2) + 1; \
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34 | h = hval % tablesize; \
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35 | } while (0)
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36 |
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37 |
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38 |
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39 | #endif
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