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      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 (at) 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
     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