lib/libcurses/cur_hash.c

   1 /*      $NetBSD: cur_hash.c,v 1.12 2005/02/18 22:16:27 dsl 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 1.12 2005/02/18 22:16:27 dsl 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 u_int
  50 __hash_more(const void  *v_s, size_t len, u_int h)
  51 {
  52         u_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 }