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/* 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; either version 2 of the License, 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, 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
MyFlags Flags
DESCRIPTION
my_chsize() truncates file if shorter, else expand with zero.
RETURN VALUE
0 Ok
1 Error
*/
int my_chsize(File fd, my_off_t newlength, myf MyFlags)
{
DBUG_ENTER("my_chsize");
DBUG_PRINT("my",("fd: %d length: %lu MyFlags: %d",fd,(ulong) newlength,
MyFlags));
#ifdef HAVE_CHSIZE
if (chsize(fd,(off_t) newlength))
{
DBUG_PRINT("error",("errno: %d",errno));
my_errno=errno;
if (MyFlags & MY_WME)
my_error(EE_CANT_CHSIZE,MYF(ME_BELL+ME_WAITTANG),errno);
DBUG_RETURN(1);
}
DBUG_RETURN(0);
#else
/* if file is shorter, expand with null, else fill unused part with null */
{
my_off_t oldsize;
char buff[IO_SIZE];
oldsize = my_seek(fd, 0L, MY_SEEK_END, MYF(MY_WME+MY_FAE));
DBUG_PRINT("info",("old_size: %ld", (ulong) oldsize));
#ifdef HAVE_FTRUNCATE
if (oldsize > newlength)
{
if (ftruncate(fd, (off_t) newlength))
{
my_errno=errno;
DBUG_PRINT("error",("errno: %d",errno));
if (MyFlags & MY_WME)
my_error(EE_CANT_CHSIZE, MYF(ME_BELL+ME_WAITTANG), errno);
DBUG_RETURN(1);
}
DBUG_RETURN(0);
}
#else
if (oldsize > newlength)
{ /* Fill diff with null */
VOID(my_seek(fd, newlength, MY_SEEK_SET, MYF(MY_WME+MY_FAE)));
swap(my_off_t, newlength, oldsize);
}
#endif
/* Full file with 0 until it's as big as requested */
bzero(buff,IO_SIZE);
while (newlength-oldsize > IO_SIZE)
{
if (my_write(fd,(byte*) buff,IO_SIZE,MYF(MY_NABP)))
goto err;
oldsize+= IO_SIZE;
}
if (my_write(fd,(byte*) buff,(uint) (newlength-oldsize),MYF(MY_NABP)))
goto err;
DBUG_RETURN(0);
err:
if (MyFlags & MY_WME)
my_error(EE_CANT_CHSIZE,MYF(ME_BELL+ME_WAITTANG),my_errno);
DBUG_PRINT("error",("errno: %d",my_errno));
DBUG_RETURN(1);
}
#endif
} /* my_chsize */
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