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 */ 53 uint32_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 */ 62 uint32_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 */ 69 void hash_set_raninit(uint32_t v); 70 71 #endif /* UTIL_STORAGE_LOOKUP3_H */ 72