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
|
/***********************************************************************/
/* */
/* OCaml */
/* */
/* Xavier Leroy, projet Cristal, INRIA Rocquencourt */
/* */
/* Copyright 1996 Institut National de Recherche en Informatique et */
/* en Automatique. All rights reserved. This file is distributed */
/* under the terms of the GNU Library General Public License, with */
/* the special exception on linking described in file ../../LICENSE. */
/* */
/***********************************************************************/
#include <errno.h>
#include <sys/types.h>
#include <caml/mlvalues.h>
#include <caml/alloc.h>
#include <caml/io.h>
#include <caml/signals.h>
#include "unixsupport.h"
#ifdef HAS_UNISTD
#include <unistd.h>
#else
#define SEEK_SET 0
#define SEEK_CUR 1
#define SEEK_END 2
#endif
#ifndef EOVERFLOW
#define EOVERFLOW ERANGE
#endif
static int seek_command_table[] = {
SEEK_SET, SEEK_CUR, SEEK_END
};
CAMLprim value unix_lseek(value fd, value ofs, value cmd)
{
file_offset ret;
caml_enter_blocking_section();
ret = lseek(Int_val(fd), Long_val(ofs),
seek_command_table[Int_val(cmd)]);
caml_leave_blocking_section();
if (ret == -1) uerror("lseek", Nothing);
if (ret > Max_long) unix_error(EOVERFLOW, "lseek", Nothing);
return Val_long(ret);
}
CAMLprim value unix_lseek_64(value fd, value ofs, value cmd)
{
file_offset ret;
/* [ofs] is an Int64, which is stored as a custom block; we must therefore
extract its contents before dropping the runtime lock, or it might be
moved. */
file_offset ofs_c = File_offset_val(ofs);
caml_enter_blocking_section();
ret = lseek(Int_val(fd), ofs_c, seek_command_table[Int_val(cmd)]);
caml_leave_blocking_section();
if (ret == -1) uerror("lseek", Nothing);
return Val_file_offset(ret);
}
|
