115 lines
3.3 KiB
C
115 lines
3.3 KiB
C
/* Copyright (C) 2000 MySQL AB
|
|
|
|
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; version 2 of the License.
|
|
|
|
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, write to the Free Software
|
|
Foundation, Inc., 59 Temple Place, Suite 330, Boston, MA 02111-1307 USA */
|
|
|
|
#include "mysys_priv.h"
|
|
#include "mysys_err.h"
|
|
#include "m_string.h"
|
|
|
|
/*
|
|
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)
|
|
{
|
|
#if defined(HAVE_SETFILEPOINTER)
|
|
/* This is for the moment only true on windows */
|
|
long is_success;
|
|
HANDLE win_file= (HANDLE) _get_osfhandle(fd);
|
|
long length_low, length_high;
|
|
length_low= (long) (ulong) newlength;
|
|
length_high= (long) ((ulonglong) newlength >> 32);
|
|
is_success= SetFilePointer(win_file, length_low, &length_high, FILE_BEGIN);
|
|
if (is_success == -1 && (my_errno= GetLastError()) != NO_ERROR)
|
|
goto err;
|
|
if (SetEndOfFile(win_file))
|
|
DBUG_RETURN(0);
|
|
my_errno= GetLastError();
|
|
goto err;
|
|
#elif defined(HAVE_FTRUNCATE)
|
|
if (ftruncate(fd, (off_t) newlength))
|
|
{
|
|
my_errno= errno;
|
|
goto err;
|
|
}
|
|
DBUG_RETURN(0);
|
|
#elif defined(HAVE_CHSIZE)
|
|
if (chsize(fd, (off_t) newlength))
|
|
{
|
|
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;
|
|
}
|
|
swap_variables(my_off_t, newlength, oldsize);
|
|
#endif
|
|
}
|
|
|
|
/* Full file with 'filler' until it's as big as requested */
|
|
bfill(buff, IO_SIZE, filler);
|
|
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)
|
|
my_error(EE_CANT_CHSIZE, MYF(ME_BELL+ME_WAITTANG), my_errno);
|
|
DBUG_RETURN(1);
|
|
} /* my_chsize */
|