lib/libc/citrus/citrus_db_hash.c

   1 /*      $NetBSD: citrus_db_hash.c,v 1.4 2004/01/02 21:49:35 itojun Exp $        */
   2
   3 /*-
   4  * Copyright (c)2003 Citrus Project,
   5  * 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  *
  16  * THIS SOFTWARE IS PROVIDED BY THE AUTHOR AND CONTRIBUTORS ``AS IS'' AND
  17  * ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE
  18  * IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
  19  * ARE DISCLAIMED.  IN NO EVENT SHALL THE AUTHOR OR CONTRIBUTORS BE LIABLE
  20  * FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL
  21  * DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS
  22  * OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION)
  23  * HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT
  24  * LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY
  25  * OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF
  26  * SUCH DAMAGE.
  27  */
  28
  29 #if HAVE_NBTOOL_CONFIG_H
  30 #include "nbtool_config.h"
  31 #endif
  32
  33 #include <sys/cdefs.h>
  34 #if defined(LIBC_SCCS) && !defined(lint)
  35 __RCSID("$NetBSD: citrus_db_hash.c,v 1.4 2004/01/02 21:49:35 itojun Exp $");
  36 #endif /* LIBC_SCCS and not lint */
  37
  38 #ifndef HOSTPROG
  39 #include "namespace.h"
  40 #endif
  41 #include <assert.h>
  42 #include <stdio.h>
  43 #include <string.h>
  44 #include <sys/types.h>
  45
  46 #include "citrus_namespace.h"
  47 #include "citrus_types.h"
  48 #include "citrus_bcs.h"
  49 #include "citrus_region.h"
  50 #include "citrus_db_hash.h"
  51
  52 uint32_t
  53 /*ARGSUSED*/
  54 _citrus_db_hash_std(void *closure, struct _region *r)
  55 {
  56         const uint8_t *p = _region_head(r);
  57         uint32_t hash = 0, tmp;
  58         size_t i;
  59
  60         for (i = _region_size(r); i > 0; i--) {
  61                 hash <<= 4;
  62                 hash += _bcs_tolower(*p);
  63                 tmp = hash & 0xF0000000;
  64                 if (tmp != 0) {
  65                         hash ^= tmp;
  66                         hash ^= tmp >> 24;
  67                 }
  68                 p++;
  69         }
  70         return hash;
  71 }