1 /* $OpenBSD: ohash_interval.c,v 1.3 2006/01/16 15:52:25 espie Exp $ */
2 /* ex:ts=8 sw=4:
3 */
4
5 /* Copyright (c) 1999, 2004 Marc Espie <espie@openbsd.org>
6 *
7 * Permission to use, copy, modify, and distribute this software for any
8 * purpose with or without fee is hereby granted, provided that the above
9 * copyright notice and this permission notice appear in all copies.
10 *
11 * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
12 * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
13 * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
14 * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
15 * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
16 * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
17 * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18 */
19
20 #include "ohash_int.h"
21
22 uint32_t
ohash_interval(const char * s,const char ** e)23 ohash_interval(const char *s, const char **e)
24 {
25 uint32_t k;
26
27 if (!*e)
28 *e = s + strlen(s);
29 if (s == *e)
30 k = 0;
31 else
32 k = *s++;
33 while (s != *e)
34 k = ((k << 2) | (k >> 30)) ^ *s++;
35 return k;
36 }
37