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
|
/* Copyright (c) 2000, 2017, Oracle and/or its affiliates. All rights reserved.
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License, version 2.0,
as published by the Free Software Foundation.
This program is also distributed with certain software (including
but not limited to OpenSSL) that is licensed under separate terms,
as designated in a particular file or component or in included license
documentation. The authors of MySQL hereby grant you an additional
permission to link the program and your derivative works with the
separately licensed software that they have included with MySQL.
Without limiting anything contained in the foregoing, this file,
which is part of C Driver for MySQL (Connector/C), is also subject to the
Universal FOSS Exception, version 1.0, a copy of which can be found at
http://oss.oracle.com/licenses/universal-foss-exception.
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, version 2.0, 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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA */
/**
@file mysys/my_chsize.cc
*/
#include "my_config.h"
#include <errno.h>
#include <string.h>
#include <sys/types.h>
#ifdef HAVE_UNISTD_H
#include <unistd.h>
#endif
#include "my_dbug.h"
#include "my_inttypes.h"
#include "my_io.h"
#include "my_sys.h"
#include "my_thread_local.h"
#include "mysys_err.h"
#ifdef _WIN32
#include "mysys/mysys_priv.h"
#endif
/*
Change size of file.
SYNOPSIS
my_chsize()
fd File descriptor
new_length New file size
filler If we don't have truncate, fill up all bytes after
new_length with this character
MyFlags Flags
DESCRIPTION
my_chsize() truncates file if shorter else fill with the filler character.
The function also changes the file pointer. Usually it points to the end
of the file after execution.
RETURN VALUE
0 Ok
1 Error
*/
int my_chsize(File fd, my_off_t newlength, int filler, myf MyFlags) {
my_off_t oldsize;
uchar buff[IO_SIZE];
DBUG_ENTER("my_chsize");
DBUG_PRINT("my", ("fd: %d length: %lu MyFlags: %d", fd, (ulong)newlength,
MyFlags));
if ((oldsize = my_seek(fd, 0L, MY_SEEK_END, MYF(MY_WME + MY_FAE))) ==
newlength)
DBUG_RETURN(0);
DBUG_PRINT("info", ("old_size: %ld", (ulong)oldsize));
if (oldsize > newlength) {
#ifdef _WIN32
if (my_win_chsize(fd, newlength)) {
set_my_errno(errno);
goto err;
}
DBUG_RETURN(0);
#elif defined(HAVE_FTRUNCATE)
if (ftruncate(fd, (off_t)newlength)) {
set_my_errno(errno);
goto err;
}
DBUG_RETURN(0);
#else
/*
Fill space between requested length and true length with 'filler'
We should never come here on any modern machine
*/
if (my_seek(fd, newlength, MY_SEEK_SET, MYF(MY_WME + MY_FAE)) ==
MY_FILEPOS_ERROR) {
goto err;
}
std::swap(newlength, oldsize);
#endif
}
/* Full file with 'filler' until it's as big as requested */
memset(buff, filler, IO_SIZE);
while (newlength - oldsize > IO_SIZE) {
if (my_write(fd, buff, IO_SIZE, MYF(MY_NABP))) goto err;
oldsize += IO_SIZE;
}
if (my_write(fd, buff, (size_t)(newlength - oldsize), MYF(MY_NABP))) goto err;
DBUG_RETURN(0);
err:
DBUG_PRINT("error", ("errno: %d", errno));
if (MyFlags & MY_WME) {
char errbuf[MYSYS_STRERROR_SIZE];
my_error(EE_CANT_CHSIZE, MYF(0), my_errno(),
my_strerror(errbuf, sizeof(errbuf), my_errno()));
}
DBUG_RETURN(1);
} /* my_chsize */
|
