1*4afad3d8SPeter Avalos /* $OpenBSD: ohash_interval.c,v 1.3 2006/01/16 15:52:25 espie Exp $ */
2*4afad3d8SPeter Avalos /* ex:ts=8 sw=4:
3*4afad3d8SPeter Avalos */
4*4afad3d8SPeter Avalos
5*4afad3d8SPeter Avalos /* Copyright (c) 1999, 2004 Marc Espie <espie@openbsd.org>
6*4afad3d8SPeter Avalos *
7*4afad3d8SPeter Avalos * Permission to use, copy, modify, and distribute this software for any
8*4afad3d8SPeter Avalos * purpose with or without fee is hereby granted, provided that the above
9*4afad3d8SPeter Avalos * copyright notice and this permission notice appear in all copies.
10*4afad3d8SPeter Avalos *
11*4afad3d8SPeter Avalos * THE SOFTWARE IS PROVIDED "AS IS" AND THE AUTHOR DISCLAIMS ALL WARRANTIES
12*4afad3d8SPeter Avalos * WITH REGARD TO THIS SOFTWARE INCLUDING ALL IMPLIED WARRANTIES OF
13*4afad3d8SPeter Avalos * MERCHANTABILITY AND FITNESS. IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR
14*4afad3d8SPeter Avalos * ANY SPECIAL, DIRECT, INDIRECT, OR CONSEQUENTIAL DAMAGES OR ANY DAMAGES
15*4afad3d8SPeter Avalos * WHATSOEVER RESULTING FROM LOSS OF USE, DATA OR PROFITS, WHETHER IN AN
16*4afad3d8SPeter Avalos * ACTION OF CONTRACT, NEGLIGENCE OR OTHER TORTIOUS ACTION, ARISING OUT OF
17*4afad3d8SPeter Avalos * OR IN CONNECTION WITH THE USE OR PERFORMANCE OF THIS SOFTWARE.
18*4afad3d8SPeter Avalos *
19*4afad3d8SPeter Avalos * $FreeBSD: src/usr.bin/m4/lib/ohash_interval.c,v 1.2 2012/11/17 01:54:24 svnexp Exp $
20*4afad3d8SPeter Avalos */
21*4afad3d8SPeter Avalos
22*4afad3d8SPeter Avalos #include "ohash_int.h"
23*4afad3d8SPeter Avalos
24*4afad3d8SPeter Avalos uint32_t
ohash_interval(const char * s,const char ** e)25*4afad3d8SPeter Avalos ohash_interval(const char *s, const char **e)
26*4afad3d8SPeter Avalos {
27*4afad3d8SPeter Avalos uint32_t k;
28*4afad3d8SPeter Avalos
29*4afad3d8SPeter Avalos if (!*e)
30*4afad3d8SPeter Avalos *e = s + strlen(s);
31*4afad3d8SPeter Avalos if (s == *e)
32*4afad3d8SPeter Avalos k = 0;
33*4afad3d8SPeter Avalos else
34*4afad3d8SPeter Avalos k = *s++;
35*4afad3d8SPeter Avalos while (s != *e)
36*4afad3d8SPeter Avalos k = ((k << 2) | (k >> 30)) ^ *s++;
37*4afad3d8SPeter Avalos return k;
38*4afad3d8SPeter Avalos }
39