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
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
188
|
/* ftruncate emulations for native Windows.
Copyright (C) 1992-2013 Free Software Foundation, Inc.
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, 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 <config.h>
/* Specification. */
#include <unistd.h>
#if HAVE_CHSIZE
/* A native Windows platform. */
# include <errno.h>
# if _GL_WINDOWS_64_BIT_OFF_T
/* Large File Support: off_t is 64-bit, but chsize() takes only a 32-bit
argument. So, define a 64-bit safe SetFileSize function ourselves. */
/* Ensure that <windows.h> declares GetFileSizeEx. */
# undef _WIN32_WINNT
# define _WIN32_WINNT 0x500
/* Get declarations of the native Windows API functions. */
# define WIN32_LEAN_AND_MEAN
# include <windows.h>
/* Get _get_osfhandle. */
# include "msvc-nothrow.h"
static BOOL
SetFileSize (HANDLE h, LONGLONG size)
{
LARGE_INTEGER old_size;
if (!GetFileSizeEx (h, &old_size))
return FALSE;
if (size != old_size.QuadPart)
{
/* Duplicate the handle, so we are free to modify its file position. */
HANDLE curr_process = GetCurrentProcess ();
HANDLE tmph;
if (!DuplicateHandle (curr_process, /* SourceProcessHandle */
h, /* SourceHandle */
curr_process, /* TargetProcessHandle */
(PHANDLE) &tmph, /* TargetHandle */
(DWORD) 0, /* DesiredAccess */
FALSE, /* InheritHandle */
DUPLICATE_SAME_ACCESS)) /* Options */
return FALSE;
if (size < old_size.QuadPart)
{
/* Reduce the size. */
LONG size_hi = (LONG) (size >> 32);
if (SetFilePointer (tmph, (LONG) size, &size_hi, FILE_BEGIN)
== INVALID_SET_FILE_POINTER
&& GetLastError() != NO_ERROR)
{
CloseHandle (tmph);
return FALSE;
}
if (!SetEndOfFile (tmph))
{
CloseHandle (tmph);
return FALSE;
}
}
else
{
/* Increase the size by adding zero bytes at the end. */
static char zero_bytes[1024];
LONG pos_hi = 0;
LONG pos_lo = SetFilePointer (tmph, (LONG) 0, &pos_hi, FILE_END);
LONGLONG pos;
if (pos_lo == INVALID_SET_FILE_POINTER
&& GetLastError() != NO_ERROR)
{
CloseHandle (tmph);
return FALSE;
}
pos = ((LONGLONG) pos_hi << 32) | (ULONGLONG) (ULONG) pos_lo;
while (pos < size)
{
DWORD written;
LONGLONG count = size - pos;
if (count > sizeof (zero_bytes))
count = sizeof (zero_bytes);
if (!WriteFile (tmph, zero_bytes, (DWORD) count, &written, NULL)
|| written == 0)
{
CloseHandle (tmph);
return FALSE;
}
pos += (ULONGLONG) (ULONG) written;
}
}
/* Close the handle. */
CloseHandle (tmph);
}
return TRUE;
}
int
ftruncate (int fd, off_t length)
{
HANDLE handle = (HANDLE) _get_osfhandle (fd);
if (handle == INVALID_HANDLE_VALUE)
{
errno = EBADF;
return -1;
}
if (length < 0)
{
errno = EINVAL;
return -1;
}
if (!SetFileSize (handle, length))
{
switch (GetLastError ())
{
case ERROR_ACCESS_DENIED:
errno = EACCES;
break;
case ERROR_HANDLE_DISK_FULL:
case ERROR_DISK_FULL:
case ERROR_DISK_TOO_FRAGMENTED:
errno = ENOSPC;
break;
default:
errno = EIO;
break;
}
return -1;
}
return 0;
}
# else
# include <io.h>
# if HAVE_MSVC_INVALID_PARAMETER_HANDLER
# include "msvc-inval.h"
static int
chsize_nothrow (int fd, long length)
{
int result;
TRY_MSVC_INVAL
{
result = chsize (fd, length);
}
CATCH_MSVC_INVAL
{
result = -1;
errno = EBADF;
}
DONE_MSVC_INVAL;
return result;
}
# define chsize chsize_nothrow
# endif
int
ftruncate (int fd, off_t length)
{
return chsize (fd, length);
}
# endif
#endif
|
