mariadb/mysys/my_write.c
2019-05-19 20:55:37 +02:00

120 lines
3.6 KiB
C

/* Copyright (c) 2000, 2016, Oracle and/or its affiliates.
Copyright (c) 2011, 2016, MariaDB
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., 51 Franklin St, Fifth Floor, Boston, MA 02110-1335 USA */
#include "mysys_priv.h"
#include "mysys_err.h"
#include <errno.h>
/* Write a chunk of bytes to a file */
size_t my_write(File Filedes, const uchar *Buffer, size_t Count, myf MyFlags)
{
size_t writtenbytes, written;
uint errors;
DBUG_ENTER("my_write");
DBUG_PRINT("my",("fd: %d Buffer: %p Count: %lu MyFlags: %lu",
Filedes, Buffer, (ulong) Count, MyFlags));
errors= 0; written= 0;
if (!(MyFlags & (MY_WME | MY_FAE | MY_FNABP)))
MyFlags|= my_global_flags;
/* The behavior of write(fd, buf, 0) is not portable */
if (unlikely(!Count))
DBUG_RETURN(0);
for (;;)
{
#ifdef _WIN32
if(Filedes < 0)
{
my_errno= errno= EBADF;
DBUG_RETURN((size_t)-1);
}
writtenbytes= my_win_write(Filedes, Buffer, Count);
#else
writtenbytes= write(Filedes, Buffer, Count);
#endif
/**
To simulate the write error set the errno = error code
and the number pf written bytes to -1.
*/
DBUG_EXECUTE_IF ("simulate_file_write_error",
if (!errors) {
errno= ENOSPC;
writtenbytes= (size_t) -1;
});
if (writtenbytes == Count)
break;
if (writtenbytes != (size_t) -1)
{ /* Safeguard */
written+= writtenbytes;
Buffer+= writtenbytes;
Count-= writtenbytes;
}
my_errno= errno;
DBUG_PRINT("error",("Write only %ld bytes, error: %d",
(long) writtenbytes, my_errno));
#ifndef NO_BACKGROUND
if (my_thread_var->abort)
MyFlags&= ~ MY_WAIT_IF_FULL; /* End if aborted by user */
if ((my_errno == ENOSPC || my_errno == EDQUOT) &&
(MyFlags & MY_WAIT_IF_FULL))
{
wait_for_free_space(my_filename(Filedes), errors);
errors++;
continue;
}
if ((writtenbytes == 0 || writtenbytes == (size_t) -1))
{
if (my_errno == EINTR)
{
DBUG_PRINT("debug", ("my_write() was interrupted and returned %ld",
(long) writtenbytes));
continue; /* Interrupted */
}
if (!writtenbytes && !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
/* Don't give a warning if it's ok that we only write part of the data */
if (MyFlags & (MY_NABP | MY_FNABP))
{
if (MyFlags & (MY_WME | MY_FAE | MY_FNABP))
{
my_error(EE_WRITE, MYF(ME_BELL | (MyFlags & (ME_NOTE | ME_ERROR_LOG))),
my_filename(Filedes),my_errno);
}
DBUG_RETURN(MY_FILE_ERROR); /* Error on read */
}
break; /* Return bytes written */
}
if (MyFlags & (MY_NABP | MY_FNABP))
DBUG_RETURN(0); /* Want only errors */
DBUG_RETURN(writtenbytes+written);
} /* my_write */