1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
|
/*
* Copyright (C) 2010 Regents of the University of Michigan
*
* This program is free software: you can redistribute it and/or modify
* it under the terms of the GNU General Public License as published by
* the Free Software Foundation, either version 3 of the License, or
* (at your option) any later version.
*
* This program is distributed in the hope that it will be useful,
* but WITHOUT ANY WARRANTY; without even the implied warranty of
* MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
* GNU General Public License for more details.
*
* You should have received a copy of the GNU General Public License
* along with this program. If not, see <http://www.gnu.org/licenses/>.
*/
#include "Hash.h"
#include <ctype.h>
// ********************************************************
//
// This code is based on the original by Robert Jenkins.
//
// http://burtleburtle.net/bob/hash/doobs.html
//
// ********************************************************
#define MIX_INTEGERS(a,b,c) \
{ \
a -= b; a -= c; a ^= (c>>13); \
b -= c; b -= a; b ^= (a<<8); \
c -= a; c -= b; c ^= (b>>13); \
a -= b; a -= c; a ^= (c>>12); \
b -= c; b -= a; b ^= (a<<16); \
c -= a; c -= b; c ^= (b>>5); \
a -= b; a -= c; a ^= (c>>3); \
b -= c; b -= a; b ^= (a<<10); \
c -= a; c -= b; c ^= (b>>15); \
}
#define ui (unsigned int)
unsigned int hash(const unsigned char * key, unsigned int length, unsigned int initval)
{
unsigned int a = 0x9e3779b9;
unsigned int b = 0x9e3779b9;
unsigned int c = initval;
unsigned int len = length;
/*---------------------------------------- handle most of the key */
while (len >= 12)
{
a += (key[0] +(ui(key[1])<<8) +(ui(key[2])<<16) +(ui(key[3])<<24));
b += (key[4] +(ui(key[5])<<8) +(ui(key[6])<<16) +(ui(key[7])<<24));
c += (key[8] +(ui(key[9])<<8) +(ui(key[10])<<16)+(ui(key[11])<<24));
MIX_INTEGERS(a,b,c);
key += 12;
len -= 12;
}
/*------------------------------------- handle the last 11 bytes */
c += length;
switch (len) /* all the case statements fall through */
{
case 11:
c+=(ui(key[10])<<24);
case 10:
c+=(ui(key[9])<<16);
case 9 :
c+=(ui(key[8])<<8);
/* the first byte of c is reserved for the length */
case 8 :
b+=(ui(key[7])<<24);
case 7 :
b+=(ui(key[6])<<16);
case 6 :
b+=(ui(key[5])<<8);
case 5 :
b+=key[4];
case 4 :
a+=(ui(key[3])<<24);
case 3 :
a+=(ui(key[2])<<16);
case 2 :
a+=(ui(key[1])<<8);
case 1 :
a+=key[0];
/* case 0: nothing left to add */
}
MIX_INTEGERS(a,b,c);
/*-------------------------------------------- report the result */
return c;
}
unsigned int hash_no_case(const unsigned char * key, unsigned int length, unsigned int initval)
{
unsigned int a = 0x9e3779b9;
unsigned int b = 0x9e3779b9;
unsigned int c = initval;
unsigned int len = length;
/*---------------------------------------- handle most of the key */
while (len >= 12)
{
a += (toupper(key[0]) +(ui(toupper(key[1]))<<8) +(ui(toupper(key[2]))<<16) +(ui(toupper(key[3]))<<24));
b += (toupper(key[4]) +(ui(toupper(key[5]))<<8) +(ui(toupper(key[6]))<<16) +(ui(toupper(key[7]))<<24));
c += (toupper(key[8]) +(ui(toupper(key[9]))<<8) +(ui(toupper(key[10]))<<16)+(ui(toupper(key[11]))<<24));
MIX_INTEGERS(a,b,c);
key += 12;
len -= 12;
}
/*------------------------------------- handle the last 11 bytes */
c += length;
switch (len) /* all the case statements fall through */
{
case 11:
c+=(ui(toupper(key[10]))<<24);
case 10:
c+=(ui(toupper(key[9]))<<16);
case 9 :
c+=(ui(toupper(key[8]))<<8);
/* the first byte of c is reserved for the length */
case 8 :
b+=(ui(toupper(key[7]))<<24);
case 7 :
b+=(ui(toupper(key[6]))<<16);
case 6 :
b+=(ui(toupper(key[5]))<<8);
case 5 :
b+=toupper(key[4]);
case 4 :
a+=(ui(toupper(key[3]))<<24);
case 3 :
a+=(ui(toupper(key[2]))<<16);
case 2 :
a+=(ui(toupper(key[1]))<<8);
case 1 :
a+=toupper(key[0]);
/* case 0: nothing left to add */
}
MIX_INTEGERS(a,b,c);
/*-------------------------------------------- report the result */
return c;
}
|
