| Geant4 Cross Reference |
1 //
2 // ********************************************************************
3 // * License and Disclaimer *
4 // * *
5 // * The Geant4 software is copyright of the Copyright Holders of *
6 // * the Geant4 Collaboration. It is provided under the terms and *
7 // * conditions of the Geant4 Software License, included in the file *
8 // * LICENSE and available at http://cern.ch/geant4/license . These *
9 // * include a list of copyright holders. *
10 // * *
11 // * Neither the authors of this software system, nor their employing *
12 // * institutes,nor the agencies providing financial support for this *
13 // * work make any representation or warranty, express or implied, *
14 // * regarding this software system or assume any liability for its *
15 // * use. Please see the license in the file LICENSE and URL above *
16 // * for the full disclaimer and the limitation of liability. *
17 // * *
18 // * This code implementation is the result of the scientific and *
19 // * technical work of the GEANT4 collaboration. *
20 // * By using, copying, modifying or distributing the software (or *
21 // * any work based on the software) you agree to acknowledge its *
22 // * use in resulting scientific publications, and indicate your *
23 // * acceptance of all terms of the Geant4 Software license. *
24 // ********************************************************************
25 //
26 //
27 // G4Hashing.cc
28 // Geant4
29 //
30 // Created by Mathieu Karamitros
31 //
32 //
33
34 #include "DNAHashing.hh"
35
36 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
37
38 namespace G4::hashing
39 {
40 namespace crc32
41 {
42 uint32_t Hash(const char* str, size_t len)
43 {
44 uint32_t remainder = 0xFFFFFFFF;
45 for (size_t idx = 0; idx < len; ++idx) {
46 remainder = (remainder >> 8) ^ fCrc_table[(remainder ^ str[idx]) & 0x000000FF];
47 }
48 return remainder ^ 0xFFFFFFFF;
49 }
50
51 uint32_t Hash(const std::string& str)
52 {
53 return Hash(str.c_str(), str.size());
54 }
55 } // namespace crc32
56
57 namespace fnv
58 {
59 size_t Hash(const std::string& str)
60 {
61 size_t hash = fnv_offset_basis;
62 for (size_t i = 0; i < str.length(); i++) {
63 hash = hash ^ (str[i]); // xor the low 8 bits
64 hash = hash * fnv_prime; // multiply by the magic number
65 }
66 return hash;
67 }
68 } // namespace fnv
69
70 namespace larson
71 {
72 size_t Hash(const char* str, unsigned int seed)
73 {
74 size_t hash = seed;
75 while (*str != 0) {
76 hash = hash * 101 + *str++;
77 }
78 return hash;
79 }
80
81 size_t Hash(std::string str, unsigned int seed)
82 {
83 return Hash(str.c_str(), seed);
84 }
85 } // namespace larson
86 } // namespace G4::hashing
87
88 //....oooOO0OOooo........oooOO0OOooo........oooOO0OOooo........oooOO0OOooo......
89