00001 /*---------------------------------------------------------------------------*\ 00002 ========= | 00003 \\ / F ield | OpenFOAM: The Open Source CFD Toolbox 00004 \\ / O peration | 00005 \\ / A nd | Copyright (C) 1991-2010 OpenCFD Ltd. 00006 \\/ M anipulation | 00007 ------------------------------------------------------------------------------- 00008 License 00009 This file is part of OpenFOAM. 00010 00011 OpenFOAM is free software: you can redistribute it and/or modify it 00012 under the terms of the GNU General Public License as published by 00013 the Free Software Foundation, either version 3 of the License, or 00014 (at your option) any later version. 00015 00016 OpenFOAM is distributed in the hope that it will be useful, but WITHOUT 00017 ANY WARRANTY; without even the implied warranty of MERCHANTABILITY or 00018 FITNESS FOR A PARTICULAR PURPOSE. See the GNU General Public License 00019 for more details. 00020 00021 You should have received a copy of the GNU General Public License 00022 along with OpenFOAM. If not, see <http://www.gnu.org/licenses/>. 00023 00024 InNamespace 00025 Foam 00026 00027 Description 00028 Misc. hashing functions, mostly from Bob Jenkins. 00029 00030 The Jenkins hashing function(s) is similar in speed to Paul Hsieh's 00031 SuperFast hash, but is public domain, supports incremental hashing 00032 and has been reported to have better characteristics. 00033 It is also what postgresql seems to be using. 00034 00035 SeeAlso 00036 http://burtleburtle.net/bob/c/lookup3.c 00037 and HasherInt.H for a specialized version 00038 00039 SourceFiles 00040 Hasher.C 00041 00042 \*---------------------------------------------------------------------------*/ 00043 00044 #ifndef Hasher_H 00045 #define Hasher_H 00046 00047 #include <cstddef> 00048 00049 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // 00050 00051 namespace Foam 00052 { 00053 00054 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // 00055 00056 //- Bob Jenkins's 96-bit mixer hashing function (lookup3) 00057 // @param[in] data - a character stream 00058 // @param[in] len - the number of bytes 00059 // @param[in] seed - the previous hash, or an arbitrary value 00060 unsigned Hasher(const void* data, size_t len, unsigned seed = 0); 00061 00062 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // 00063 00064 } // End namespace Foam 00065 00066 // * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * * // 00067 00068 #endif 00069 00070 // ************************ vim: set sw=4 sts=4 et: ************************ //
