xref: /minix3/lib/libcurses/cur_hash.c (revision 51ffecc181005cb45a40108612ee28d1daaeeb86)
1*51ffecc1SBen Gras /*	$NetBSD: cur_hash.c,v 1.12 2005/02/18 22:16:27 dsl Exp $	*/
2*51ffecc1SBen Gras 
3*51ffecc1SBen Gras /*
4*51ffecc1SBen Gras  * Copyright (c) 1992, 1993
5*51ffecc1SBen Gras  *	The Regents of the University of California.  All rights reserved.
6*51ffecc1SBen Gras  *
7*51ffecc1SBen Gras  * Redistribution and use in source and binary forms, with or without
8*51ffecc1SBen Gras  * modification, are permitted provided that the following conditions
9*51ffecc1SBen Gras  * are met:
10*51ffecc1SBen Gras  * 1. Redistributions of source code must retain the above copyright
11*51ffecc1SBen Gras  *    notice, this list of conditions and the following disclaimer.
12*51ffecc1SBen Gras  * 2. Redistributions in binary form must reproduce the above copyright
13*51ffecc1SBen Gras  *    notice, this list of conditions and the following disclaimer in the
14*51ffecc1SBen Gras  *    documentation and/or other materials provided with the distribution.
15*51ffecc1SBen Gras  * 3. Neither the name of the University nor the names of its contributors
16*51ffecc1SBen Gras  *    may be used to endorse or promote products derived from this software
17*51ffecc1SBen Gras  *    without specific prior written permission.
18*51ffecc1SBen Gras  *
19*51ffecc1SBen Gras  * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20*51ffecc1SBen Gras  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21*51ffecc1SBen Gras  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22*51ffecc1SBen Gras  * ARE DISCLAIMED.  IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23*51ffecc1SBen Gras  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24*51ffecc1SBen Gras  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25*51ffecc1SBen Gras  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26*51ffecc1SBen Gras  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27*51ffecc1SBen Gras  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28*51ffecc1SBen Gras  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29*51ffecc1SBen Gras  * SUCH DAMAGE.
30*51ffecc1SBen Gras  */
31*51ffecc1SBen Gras 
32*51ffecc1SBen Gras #include <sys/cdefs.h>
33*51ffecc1SBen Gras #ifndef lint
34*51ffecc1SBen Gras #if 0
35*51ffecc1SBen Gras static char sccsid[] = "@(#)cur_hash.c	8.1 (Berkeley) 6/4/93";
36*51ffecc1SBen Gras #else
37*51ffecc1SBen Gras __RCSID("$NetBSD: cur_hash.c,v 1.12 2005/02/18 22:16:27 dsl Exp $");
38*51ffecc1SBen Gras #endif
39*51ffecc1SBen Gras #endif				/* not lint */
40*51ffecc1SBen Gras 
41*51ffecc1SBen Gras #include <sys/types.h>
42*51ffecc1SBen Gras 
43*51ffecc1SBen Gras #include "curses.h"
44*51ffecc1SBen Gras #include "curses_private.h"
45*51ffecc1SBen Gras 
46*51ffecc1SBen Gras /*
47*51ffecc1SBen Gras  * __hash_more() is "hashpjw" from the Dragon Book, Aho, Sethi & Ullman, p.436.
48*51ffecc1SBen Gras  */
49*51ffecc1SBen Gras u_int
__hash_more(const void * v_s,size_t len,u_int h)50*51ffecc1SBen Gras __hash_more(const void  *v_s, size_t len, u_int h)
51*51ffecc1SBen Gras {
52*51ffecc1SBen Gras 	u_int g;
53*51ffecc1SBen Gras 	size_t i = 0;
54*51ffecc1SBen Gras 	const char *s = v_s;
55*51ffecc1SBen Gras 
56*51ffecc1SBen Gras 	while (i < len) {
57*51ffecc1SBen Gras 		h = (h << 4) + s[i];
58*51ffecc1SBen Gras 		if ((g = h & 0xf0000000) != 0) {
59*51ffecc1SBen Gras 			h = h ^ (g >> 24);
60*51ffecc1SBen Gras 			h = h ^ g;
61*51ffecc1SBen Gras 		}
62*51ffecc1SBen Gras 		i++;
63*51ffecc1SBen Gras 	}
64*51ffecc1SBen Gras 	return h;
65*51ffecc1SBen Gras }
66