LCOM1920-T02G10

/*        $NetBSD: hash.h,v 1.8 2014/09/05 05:46:15 matt 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 = (const uint8_t *)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 = (const uint8_t *)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 = (const uint8_t *)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 */

__BEGIN_DECLS

uint32_t        murmurhash2(const void *, size_t, uint32_t);

__END_DECLS

#endif        /* !_SYS_HASH_H_ */