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43 lines
1.3 KiB
C
43 lines
1.3 KiB
C
/* hash-pjw.c -- compute a hash value from a NUL-terminated string.
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Copyright 2001 Free Software Foundation, Inc.
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This program is free software; you can redistribute it and/or modify
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it under the terms of the GNU General Public License as published by
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the Free Software Foundation; either version 2, or (at your option)
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any later version.
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This program is distributed in the hope that it will be useful,
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but WITHOUT ANY WARRANTY; without even the implied warranty of
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MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
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GNU General Public License for more details.
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You should have received a copy of the GNU General Public License
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along with this program; if not, write to the Free Software Foundation,
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Inc., 59 Temple Place - Suite 330, Boston, MA 02111-1307, USA. */
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#if HAVE_CONFIG_H
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# include <config.h>
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#endif
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#include "hash-pjw.h"
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/* A hash function for NUL-terminated char* strings using
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the method described in Aho, Sethi, & Ullman, p 436. */
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unsigned int
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hash_pjw (const void *x, unsigned int tablesize)
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{
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const char *s = x;
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unsigned int h = 0;
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unsigned int g;
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while (*s != 0)
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{
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h = (h << 4) + *s++;
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if ((g = h & (unsigned int) 0xf0000000) != 0)
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h = (h ^ (g >> 24)) ^ g;
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}
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return (h % tablesize);
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}
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