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
|
/* vim: set sw=4 sts=4 et foldmethod=syntax : */
/*
* Copyright (c) 2007, 2008 David Leverton
*
* This file is part of the Paludis package manager. Paludis is free software;
* you can redistribute it and/or modify it under the terms of the GNU General
* Public License version 2, as published by the Free Software Foundation.
*
* Paludis 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, write to the Free Software Foundation, Inc., 59 Temple
* Place, Suite 330, Boston, MA 02111-1307 USA
*/
#ifndef PALUDIS_GUARD_PALUDIS_UTIL_BYTE_SWAP_HH
#define PALUDIS_GUARD_PALUDIS_UTIL_BYTE_SWAP_HH
#include <cstddef>
namespace paludis
{
namespace byte_swap_internals
{
template <std::size_t, typename> struct ByteSwap;
template <typename T_>
struct ByteSwap<1, T_>
{
static T_ swap(T_ x)
{
return x;
}
};
template <typename T_>
struct ByteSwap<2, T_>
{
static T_ swap(T_ x)
{
return ((x << 8) & (T_(0xFF) << 8)) | ((x >> 8) & T_(0xFF));
}
};
template <typename T_>
struct ByteSwap<4, T_>
{
static T_ swap(T_ x)
{
return ((x << 24) & (T_(0xFF) << 24)) | ((x << 8) & (T_(0xFF) << 16))
| ((x >> 8) & (T_(0xFF) << 8)) | ((x >> 24) & T_(0xFF) );
}
};
template <typename T_>
struct ByteSwap<8, T_>
{
static T_ swap(T_ x)
{
return ((x << 56) & (T_(0xFF) << 56)) | ((x << 40) & (T_(0xFF) << 48))
| ((x << 24) & (T_(0xFF) << 40)) | ((x << 8) & (T_(0xFF) << 32))
| ((x >> 8) & (T_(0xFF) << 24)) | ((x >> 24) & (T_(0xFF) << 16))
| ((x >> 40) & (T_(0xFF) << 8)) | ((x >> 56) & T_(0xFF) );
}
};
}
template <typename T_>
inline T_
byte_swap(T_ x)
{
return byte_swap_internals::ByteSwap<sizeof(T_), T_>::swap(x);
}
#ifdef PALUDIS_BIG_ENDIAN
template <typename T_>
inline T_
from_bigendian(T_ x)
{
return x;
}
template <typename T_>
inline T_
to_bigendian(T_ x)
{
return x;
}
#else
template <typename T_>
inline T_
from_bigendian(T_ x)
{
return byte_swap(x);
}
template <typename T_>
inline T_
to_bigendian(T_ x)
{
return byte_swap(x);
}
#endif
}
#endif
|
