mariadb/mysys/my_chsize.c
konstantin@mysql.com f207b33a7b Support for character set conversion in binary protocol: another go
after Monty's review.
- Item_param was rewritten.
- it turns out that we can't convert string data to character set of
  connection on the fly, because they first should be written to the binary
  log.
  To support efficient conversion we need to rewrite prepared statements
  binlogging code first.
2004-05-25 02:03:49 +04:00

113 lines
3.1 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; 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
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
RETURN VALUE
0 Ok
1 Error
*/
int my_chsize(File fd, my_off_t newlength, int filler, myf MyFlags)
{
my_off_t oldsize;
char buff[IO_SIZE];
DBUG_ENTER("my_chsize");
DBUG_PRINT("my",("fd: %d length: %lu MyFlags: %d",fd,(ulong) newlength,
MyFlags));
oldsize = my_seek(fd, 0L, MY_SEEK_END, MYF(MY_WME+MY_FAE));
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
*/
VOID(my_seek(fd, newlength, MY_SEEK_SET, MYF(MY_WME+MY_FAE)));
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,(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:
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 */