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 * $FreeBSD: src/usr.bin/m4/lib/ohash_interval.c,v 1.2 2012/11/17 01:54:24 svnexp Exp $ 20 */ 21 22 #include "ohash_int.h" 23 24 uint32_t 25 ohash_interval(const char *s, const char **e) 26 { 27 uint32_t k; 28 29 if (!*e) 30 *e = s + strlen(s); 31 if (s == *e) 32 k = 0; 33 else 34 k = *s++; 35 while (s != *e) 36 k = ((k << 2) | (k >> 30)) ^ *s++; 37 return k; 38 } 39