Home | History | Annotate | Line # | Download | only in libintl 
      1 /*	$NetBSD: strhash.c,v 1.3 2007/09/25 08:19:09 junyoung Exp $	*/
      2 
      3 /*-
      4  * Copyright (c)2003, 2004 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 #include <sys/cdefs.h>
     30 #if defined(LIBC_SCCS) && !defined(lint)
     31 __RCSID("$NetBSD: strhash.c,v 1.3 2007/09/25 08:19:09 junyoung Exp $");
     32 #endif /* LIBC_SCCS and not lint */
     33 
     34 #include <sys/param.h>
     35 #include <sys/types.h>
     36 
     37 #include "libintl_local.h"
     38 
     39 /*
     40  * string hash function by P.J.Weinberger.
     41  * this implementation is derived from src/lib/libc/citrus/citrus_db_hash.c.
     42  */
     43 uint32_t
     44 /*ARGSUSED*/
     45 __intl_string_hash(const char *str)
     46 {
     47 	const uint8_t *p;
     48 	uint32_t hash = 0, tmp;
     49 
     50 	for (p = (const uint8_t *)str; *p; p++) {
     51 		hash <<= 4;
     52 		hash += *p;
     53 		tmp = hash & 0xF0000000;
     54 		if (tmp != 0) {
     55 			hash ^= tmp;
     56 			hash ^= tmp >> 24;
     57 		}
     58 	}
     59 	return hash;
     60 }
     61