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
|
/*-
* See the file LICENSE for redistribution information.
*
* Copyright (c) 1996-2002
* Sleepycat Software. All rights reserved.
*/
#include "db_config.h"
#ifndef lint
static const char revid[] = "$Id: db_byteorder.c,v 1.1.1.1 2003/11/20 22:13:10 toshok Exp $";
#endif /* not lint */
#ifndef NO_SYSTEM_INCLUDES
#include <sys/types.h>
#endif
#include "db_int.h"
/*
* __db_isbigendian --
* Return 1 if big-endian (Motorola and Sparc), not little-endian
* (Intel and Vax). We do this work at run-time, rather than at
* configuration time so cross-compilation and general embedded
* system support is simpler.
*
* PUBLIC: int __db_isbigendian __P((void));
*/
int
__db_isbigendian()
{
union { /* From Harbison & Steele. */
long l;
char c[sizeof(long)];
} u;
u.l = 1;
return (u.c[sizeof(long) - 1] == 1);
}
/*
* __db_byteorder --
* Return if we need to do byte swapping, checking for illegal
* values.
*
* PUBLIC: int __db_byteorder __P((DB_ENV *, int));
*/
int
__db_byteorder(dbenv, lorder)
DB_ENV *dbenv;
int lorder;
{
int is_bigendian;
is_bigendian = __db_isbigendian();
switch (lorder) {
case 0:
break;
case 1234:
if (is_bigendian)
return (DB_SWAPBYTES);
break;
case 4321:
if (!is_bigendian)
return (DB_SWAPBYTES);
break;
default:
__db_err(dbenv,
"unsupported byte order, only big and little-endian supported");
return (EINVAL);
}
return (0);
}
|
