1 /* $NetBSD: cur_hash.c,v 1.14 2021/09/07 01:23:09 rin Exp $ */
2
3 /*
4 * Copyright (c) 1992, 1993
5 * The Regents of the University of California. All rights reserved.
6 *
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
9 * are met:
10 * 1. Redistributions of source code must retain the above copyright
11 * notice, this list of conditions and the following disclaimer.
12 * 2. Redistributions in binary form must reproduce the above copyright
13 * notice, this list of conditions and the following disclaimer in the
14 * documentation and/or other materials provided with the distribution.
15 * 3. Neither the name of the University nor the names of its contributors
16 * may be used to endorse or promote products derived from this software
17 * without specific prior written permission.
18 *
19 * THIS SOFTWARE IS PROVIDED BY THE REGENTS AND CONTRIBUTORS ``AS IS'' AND
20 * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
21 * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
22 * ARE DISCLAIMED. IN NO EVENT SHALL THE REGENTS OR CONTRIBUTORS BE LIABLE
23 * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
24 * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
25 * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
26 * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
27 * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
28 * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
29 * SUCH DAMAGE.
30 */
31
32 #include <sys/cdefs.h>
33 #ifndef lint
34 #if 0
35 static char sccsid[] = "@(#)cur_hash.c 8.1 (Berkeley) 6/4/93";
36 #else
37 __RCSID("$NetBSD: cur_hash.c,v 1.14 2021/09/07 01:23:09 rin Exp $");
38 #endif
39 #endif /* not lint */
40
41 #include <sys/types.h>
42
43 #include "curses.h"
44 #include "curses_private.h"
45
46 /*
47 * __hash_more() is "hashpjw" from the Dragon Book, Aho, Sethi & Ullman, p.436.
48 */
49 unsigned int
__hash_more(const void * v_s,size_t len,unsigned int h)50 __hash_more(const void *v_s, size_t len, unsigned int h)
51 {
52 unsigned int g;
53 size_t i = 0;
54 const char *s = v_s;
55
56 while (i < len) {
57 h = (h << 4) + s[i];
58 if ((g = h & 0xf0000000) != 0) {
59 h = h ^ (g >> 24);
60 h = h ^ g;
61 }
62 i++;
63 }
64 return h;
65 }
66
67 unsigned int
__hash_line(const __LDATA * cp,int ncols)68 __hash_line(const __LDATA *cp, int ncols)
69 {
70 #ifdef HAVE_WCHAR
71 unsigned int h;
72 const nschar_t *np;
73 int x;
74
75 h = 0;
76 for (x = 0; x < ncols; x++) {
77 h = __hash_more(&cp->ch, sizeof(cp->ch), h);
78 h = __hash_more(&cp->attr, sizeof(cp->attr), h);
79 for (np = cp->nsp; np != NULL; np = np->next)
80 h = __hash_more(&np->ch, sizeof(np->ch), h);
81 cp++;
82 }
83 return h;
84 #else
85 return __hash(cp, (size_t)(ncols * __LDATASIZE));
86 #endif
87 }
88