MGMDB/MySQL/my_write.c

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2011-10-02 20:48:43 -05:00
/* 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 <errno.h>
/* Write a chunk of bytes to a file */
size_t my_write(int Filedes, const uchar *Buffer, size_t Count, myf MyFlags)
{
size_t writenbytes, written;
uint errors;
DBUG_ENTER("my_write");
DBUG_PRINT("my",("Fd: %d Buffer: 0x%lx Count: %lu MyFlags: %d",
Filedes, (long) Buffer, (ulong) Count, MyFlags));
errors=0; written=0;
/* The behavior of write(fd, buf, 0) is not portable */
if (unlikely(!Count))
DBUG_RETURN(0);
for (;;)
{
if ((writenbytes= write(Filedes, Buffer, Count)) == Count)
break;
if (writenbytes != (size_t) -1)
{ /* Safeguard */
written+=writenbytes;
Buffer+=writenbytes;
Count-=writenbytes;
}
my_errno=errno;
DBUG_PRINT("error",("Write only %ld bytes, error: %d",
(long) writenbytes, my_errno));
#ifndef NO_BACKGROUND
#ifdef THREAD
if (my_thread_var->abort)
MyFlags&= ~ MY_WAIT_IF_FULL; /* End if aborted by user */
#endif
if ((my_errno == ENOSPC || my_errno == EDQUOT) &&
(MyFlags & MY_WAIT_IF_FULL))
{
wait_for_free_space(my_filename(Filedes), errors);
errors++;
continue;
}
if ((writenbytes == 0 || writenbytes == (size_t) -1))
{
if (my_errno == EINTR)
{
DBUG_PRINT("debug", ("my_write() was interrupted and returned %ld",
(long) writenbytes));
continue; /* Interrupted */
}
if (!writenbytes && !errors++) /* Retry once */
{
/* We may come here if the file quota is exeeded */
errno=EFBIG; /* Assume this is the error */
continue;
}
}
else
continue; /* Retry */
#endif
if (MyFlags & (MY_NABP | MY_FNABP))
{
if (MyFlags & (MY_WME | MY_FAE | MY_FNABP))
{
my_error(EE_WRITE, MYF(ME_BELL+ME_WAITTANG),
my_filename(Filedes),my_errno);
}
DBUG_RETURN(MY_FILE_ERROR); /* Error on read */
}
else
break; /* Return bytes written */
}
if (MyFlags & (MY_NABP | MY_FNABP))
DBUG_RETURN(0); /* Want only errors */
DBUG_RETURN(writenbytes+written);
} /* my_write */