104 lines
3.2 KiB
C
104 lines
3.2 KiB
C
|
/* $NetBSD: hash.h,v 1.6 2008/04/28 20:24:10 martin Exp $ */
|
||
|
|
|
||
|
|
/*-
|
||
|
|
* Copyright (c) 2001 The NetBSD Foundation, Inc.
|
||
|
|
* All rights reserved.
|
||
|
|
*
|
||
|
|
* This code is derived from software contributed to The NetBSD Foundation
|
||
|
|
* by Luke Mewburn.
|
||
|
|
*
|
||
|
|
* Redistribution and use in source and binary forms, with or without
|
||
|
|
* modification, are permitted provided that the following conditions
|
||
|
|
* are met:
|
||
|
|
* 1. Redistributions of source code must retain the above copyright
|
||
|
|
* notice, this list of conditions and the following disclaimer.
|
||
|
|
* 2. Redistributions in binary form must reproduce the above copyright
|
||
|
|
* notice, this list of conditions and the following disclaimer in the
|
||
|
|
* documentation and/or other materials provided with the distribution.
|
||
|
|
*
|
||
|
|
* THIS SOFTWARE IS PROVIDED BY THE NETBSD FOUNDATION, INC. AND CONTRIBUTORS
|
||
|
|
* ``AS IS'' AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED
|
||
|
|
* TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR
|
||
|
|
* PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE FOUNDATION OR CONTRIBUTORS
|
||
|
|
* BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR
|
||
|
|
* CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF
|
||
|
|
* SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR PROFITS; OR BUSINESS
|
||
|
|
* INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN
|
||
|
|
* CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
|
||
|
|
* ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF ADVISED OF THE
|
||
|
|
* POSSIBILITY OF SUCH DAMAGE.
|
||
|
|
*/
|
||
|
|
|
||
|
|
#ifndef _SYS_HASH_H_
|
||
|
|
#define _SYS_HASH_H_
|
||
|
|
|
||
|
|
#include <sys/types.h>
|
||
|
|
#ifdef __HAVE_MACHINE_HASH_H
|
||
|
|
#include <machine/hash.h>
|
||
|
|
#endif
|
||
|
|
|
||
|
|
|
||
|
|
#ifndef __HAVE_HASH32_BUF /* not overridden by MD hash */
|
||
|
|
|
||
|
|
#define HASH32_BUF_INIT 5381
|
||
|
|
|
||
|
|
/*
|
||
|
|
* uint32_t
|
||
|
|
* hash32_buf(const void *bf, size_t len, uint32_t hash)
|
||
|
|
* return a 32 bit hash of the binary buffer buf (size len),
|
||
|
|
* seeded with an initial hash value of hash (usually HASH32_BUF_INIT).
|
||
|
|
*/
|
||
|
|
static __inline uint32_t
|
||
|
|
hash32_buf(const void *bf, size_t len, uint32_t hash)
|
||
|
|
{
|
||
|
|
const uint8_t *s = bf;
|
||
|
|
|
||
|
|
while (len-- != 0) /* "nemesi": k=257, r=r*257 */
|
||
|
|
hash = hash * 257 + *s++;
|
||
|
|
return (hash * 257);
|
||
|
|
}
|
||
|
|
#endif /* __HAVE_HASH32_BUF */
|
||
|
|
|
||
|
|
|
||
|
|
#ifndef __HAVE_HASH32_STR /* not overridden by MD hash */
|
||
|
|
|
||
|
|
#define HASH32_STR_INIT 5381
|
||
|
|
/*
|
||
|
|
* uint32_t
|
||
|
|
* hash32_str(const void *bf, uint32_t hash)
|
||
|
|
* return a 32 bit hash of NUL terminated ASCII string buf,
|
||
|
|
* seeded with an initial hash value of hash (usually HASH32_STR_INIT).
|
||
|
|
*/
|
||
|
|
static __inline uint32_t
|
||
|
|
hash32_str(const void *bf, uint32_t hash)
|
||
|
|
{
|
||
|
|
const uint8_t *s = bf;
|
||
|
|
uint8_t c;
|
||
|
|
|
||
|
|
while ((c = *s++) != 0)
|
||
|
|
hash = hash * 33 + c; /* "perl": k=33, r=r+r/32 */
|
||
|
|
return (hash + (hash >> 5));
|
||
|
|
}
|
||
|
|
|
||
|
|
/*
|
||
|
|
* uint32_t
|
||
|
|
* hash32_strn(const void *bf, size_t len, uint32_t hash)
|
||
|
|
* return a 32 bit hash of NUL terminated ASCII string buf up to
|
||
|
|
* a maximum of len bytes,
|
||
|
|
* seeded with an initial hash value of hash (usually HASH32_STR_INIT).
|
||
|
|
*/
|
||
|
|
static __inline uint32_t
|
||
|
|
hash32_strn(const void *bf, size_t len, uint32_t hash)
|
||
|
|
{
|
||
|
|
const uint8_t *s = bf;
|
||
|
|
uint8_t c;
|
||
|
|
|
||
|
|
while ((c = *s++) != 0 && len-- != 0)
|
||
|
|
hash = hash * 33 + c; /* "perl": k=33, r=r+r/32 */
|
||
|
|
return (hash + (hash >> 5));
|
||
|
|
}
|
||
|
|
#endif /* __HAVE_HASH32_STR */
|
||
|
|
|
||
|
|
|
||
|
|
#endif /* !_SYS_HASH_H_ */
|