1/*
2 * util/storage/lookup3.h - header file for hashing functions.
3 *
4 * Copyright (c) 2007, NLnet Labs. All rights reserved.
5 *
6 * This software is open source.
7 *
8 * Redistribution and use in source and binary forms, with or without
9 * modification, are permitted provided that the following conditions
10 * are met:
11 *
12 * Redistributions of source code must retain the above copyright notice,
13 * this list of conditions and the following disclaimer.
14 *
15 * Redistributions in binary form must reproduce the above copyright notice,
16 * this list of conditions and the following disclaimer in the documentation
17 * and/or other materials provided with the distribution.
18 *
19 * Neither the name of the NLNET LABS nor the names of its contributors may
20 * be used to endorse or promote products derived from this software without
21 * specific prior written permission.
22 *
23 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
24 * "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
25 * LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
26 * A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
27 * HOLDER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
28 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT LIMITED
29 * TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE, DATA, OR
30 * PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY THEORY OF
31 * LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT (INCLUDING
32 * NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
33 * SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
34 */
35
36/**
37 * \file
38 *
39 * This file contains header definitions for the hash functions we use.
40 * The hash functions are public domain (see lookup3.c).
41 */
42
43#ifndef UTIL_STORAGE_LOOKUP3_H
44#define UTIL_STORAGE_LOOKUP3_H
45
46/**
47 * Hash key made of 4byte chunks.
48 * @param k: the key, an array of uint32_t values
49 * @param length: the length of the key, in uint32_ts
50 * @param initval: the previous hash, or an arbitrary value
51 * @return: hash value.
52 */
53uint32_t hashword(const uint32_t *k, size_t length, uint32_t initval);
54
55/**
56 * Hash key data.
57 * @param k: the key, array of uint8_t
58 * @param length: the length of the key, in uint8_ts
59 * @param initval: the previous hash, or an arbitrary value
60 * @return: hash value.
61 */
62uint32_t hashlittle(const void *k, size_t length, uint32_t initval);
63
64/**
65 * Set the randomisation initial value, set this before threads start,
66 * and before hashing stuff (because it changes subsequent results).
67 * @param v: value
68 */
69void hash_set_raninit(uint32_t v);
70
71#endif /* UTIL_STORAGE_LOOKUP3_H */
72