util.cpp
3.76 KB
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
#include "util.h"
namespace utils {
void Util::stringUpper(string& string) {
transform(string.begin(), string.end(), string.begin(), toupper);
}
string Util::int2str(int n) {
std::stringstream ss;
ss << n;
return ss.str();
}
int Util::stringtoint(const char* string) {
return atoi(string);
}
/*
-- get bits out of buffer (max 32 bit!!!)
-- return: value
*/
unsigned long long Util::getBits(unsigned char* buf, int byte_offset, int startbit, int bitlen) {
unsigned char *b;
unsigned long v;
unsigned long mask;
unsigned long tmp_long;
int bitHigh;
b = &buf[byte_offset + (startbit >> 3)];
startbit %= 8;
switch ((bitlen - 1) >> 3) {
case -1 : // -- <=0 bits: always 0
return 0L;
break;
case 0: // -- 1..8 bit
tmp_long = (unsigned long) (
(*(b) << 8) + *(b + 1));
bitHigh = 16;
break;
case 1: // -- 9..16 bit
tmp_long = (unsigned long) (
(*(b) << 16) + (*(b + 1) << 8) + *(b + 2));
bitHigh = 24;
break;
case 2: // -- 17..24 bit
tmp_long = (unsigned long) (
(*(b) << 24) + (*(b + 1) << 16) +
(*(b + 2) << 8) + *(b + 3));
bitHigh = 32;
break;
case 3: // -- 25..32 bit
// -- to be safe, we need 32+8 bit as shift range
return (unsigned long) Util::getBits48(b, 0, startbit, bitlen);
break;
default: // -- 33.. bits: fail, deliver constant fail value
//printf("\nGET BITS: OUT OF BOUNDS\n");
return getBits48(buf, byte_offset, startbit, bitlen);
break;
}
startbit = bitHigh - startbit - bitlen;
tmp_long = tmp_long >> startbit;
mask = (1ULL << bitlen) - 1; // 1ULL !!!
v = tmp_long & mask;
return v;
}
/*
-- get bits out of buffer (max 48 bit)
-- extended bitrange, so it's slower
-- return: value
*/
long long Util::getBits48(unsigned char *buf, int byte_offset, int startbit, int bitlen) {
unsigned char *b;
unsigned long long v;
unsigned long long mask;
unsigned long long tmp;
if (bitlen > 48) {
printf("\ngetBits48() OUT OF BOUNDS\n");
return getBits64(buf, byte_offset, startbit, bitlen);
}
b = &buf[byte_offset + (startbit / 8)];
startbit %= 8;
// -- safe is 48 bitlen
tmp = (unsigned long long) (
((unsigned long long) *(b) << 48) + ((unsigned long long) *(b + 1) << 40) +
((unsigned long long) *(b + 2) << 32) + ((unsigned long long) *(b + 3) << 24) +
(*(b + 4) << 16) + (*(b + 5) << 8) + *(b + 6));
startbit = 56 - startbit - bitlen;
tmp = tmp >> startbit;
mask = (1ULL << bitlen) - 1; // 1ULL !!!
v = tmp & mask;
return v;
}
/*
-- get bits out of buffer (max 64 bit)
-- extended bitrange, so it's slower
-- return: value
*/
unsigned long long Util::getBits64(unsigned char *buf, int byte_offset, int startbit, int bitlen) {
unsigned long long x1, x2, x3;
if (bitlen <= 32) {
x3 = Util::getBits(buf, byte_offset, startbit, bitlen);
} else {
x1 = Util::getBits(buf, byte_offset, startbit, 32);
x2 = Util::getBits(buf, byte_offset, startbit + 32, bitlen - 32);
x3 = (x1 << (bitlen - 32)) + x2;
}
return x3;
}
}