1 /* 2 * libdpkg - Debian packaging suite library routines 3 * strhash.c - FNV string hashing support 4 * 5 * Copyright © 2003 Daniel Silverstone <dsilvers@digital-scurf.org> 6 * 7 * This is free software; you can redistribute it and/or modify 8 * it under the terms of the GNU General Public License as published by 9 * the Free Software Foundation; either version 2 of the License, or 10 * (at your option) any later version. 11 * 12 * This is distributed in the hope that it will be useful, 13 * but WITHOUT ANY WARRANTY; without even the implied warranty of 14 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the 15 * GNU General Public License for more details. 16 * 17 * You should have received a copy of the GNU General Public License 18 * along with this program. If not, see <https://www.gnu.org/licenses/>. 19 */ 20 21 #include <config.h> 22 #include <compat.h> 23 24 #include <dpkg/string.h> 25 26 #define FNV_OFFSET_BASIS 2166136261UL 27 #define FNV_MIXING_PRIME 16777619UL 28 29 /** 30 * Fowler/Noll/Vo -- FNV-1a simple string hash. 31 * 32 * For more info, @see <http://www.isthe.com/chongo/tech/comp/fnv/index.html>. 33 * 34 * @param str The string to hash. 35 * 36 * @return The hashed value. 37 */ 38 unsigned int str_fnv_hash(const char * str)39str_fnv_hash(const char *str) 40 { 41 register unsigned int h = FNV_OFFSET_BASIS; 42 register unsigned int p = FNV_MIXING_PRIME; 43 44 while (*str) { 45 h ^= *str++; 46 h *= p; 47 } 48 49 return h; 50 } 51