2 * SPDX-License-Identifier: BSD-2-Clause-FreeBSD
4 * Copyright (c) 2001 Tobias Weingartner
7 * Redistribution and use in source and binary forms, with or without
8 * modification, are permitted provided that the following conditions
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.
16 * THIS SOFTWARE IS PROVIDED BY THE AUTHOR ``AS IS'' AND ANY EXPRESS OR
17 * IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
18 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE DISCLAIMED.
19 * IN NO EVENT SHALL THE AUTHOR BE LIABLE FOR ANY DIRECT, INDIRECT,
20 * INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
21 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
22 * DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
23 * THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
24 * (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF
25 * THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
27 * $OpenBSD: hash.h,v 1.4 2004/05/25 18:37:23 jmc Exp $
33 #include <sys/types.h>
38 #define HASHSTEP(x,c) (((x << 5) + x) + (c))
42 * Return a 32-bit hash of the given buffer. The init
43 * value should be 0, or the previous hash value to extend
46 static __inline uint32_t
47 hash32_buf(const void *buf, size_t len, uint32_t hash)
49 const unsigned char *p = buf;
52 hash = HASHSTEP(hash, *p++);
58 * Return a 32-bit hash of the given string.
60 static __inline uint32_t
61 hash32_str(const void *buf, uint32_t hash)
63 const unsigned char *p = buf;
66 hash = HASHSTEP(hash, *p++);
72 * Return a 32-bit hash of the given string, limited by N.
74 static __inline uint32_t
75 hash32_strn(const void *buf, size_t len, uint32_t hash)
77 const unsigned char *p = buf;
80 hash = HASHSTEP(hash, *p++);
86 * Return a 32-bit hash of the given string terminated by C,
87 * (as well as 0). This is mainly here as a helper for the
88 * namei() hashing of path name parts.
90 static __inline uint32_t
91 hash32_stre(const void *buf, int end, const char **ep, uint32_t hash)
93 const unsigned char *p = buf;
95 while (*p && (*p != end))
96 hash = HASHSTEP(hash, *p++);
105 * Return a 32-bit hash of the given string, limited by N,
106 * and terminated by C (as well as 0). This is mainly here
107 * as a helper for the namei() hashing of path name parts.
109 static __inline uint32_t
110 hash32_strne(const void *buf, size_t len, int end, const char **ep,
113 const unsigned char *p = buf;
115 while (*p && (*p != end) && len--)
116 hash = HASHSTEP(hash, *p++);
126 * Hashing function from Bob Jenkins. Implementation in libkern/jenkins_hash.c.
128 uint32_t jenkins_hash(const void *, size_t, uint32_t);
129 uint32_t jenkins_hash32(const uint32_t *, size_t, uint32_t);
131 uint32_t murmur3_32_hash(const void *, size_t, uint32_t);
132 uint32_t murmur3_32_hash32(const uint32_t *, size_t, uint32_t);
136 #endif /* !_SYS_HASH_H_ */