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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 <errno.h>
/*
Read a chunk of bytes from a file with retry's if needed
The parameters are:
File descriptor
Buffer to hold at least Count bytes
Bytes to read
Flags on what to do on error
Return:
-1 on error
0 if flag has bits MY_NABP or MY_FNABP set
N number of bytes read.
*/
uint my_read(File Filedes, byte *Buffer, uint Count, myf MyFlags)
{
uint readbytes, save_count;
DBUG_ENTER("my_read");
DBUG_PRINT("my",("Fd: %d Buffer: 0x%lx Count: %u MyFlags: %d",
Filedes, (long) Buffer, Count, MyFlags));
save_count= Count;
for (;;)
{
errno= 0; /* Linux doesn't reset this */
if ((readbytes= (uint) read(Filedes, Buffer, Count)) != Count)
{
my_errno= errno ? errno : -1;
DBUG_PRINT("warning",("Read only %d bytes off %u from %d, errno: %d",
(int) readbytes, Count, Filedes, my_errno));
#ifdef THREAD
if ((readbytes == 0 || (int) readbytes == -1) && errno == EINTR)
{
DBUG_PRINT("debug", ("my_read() was interrupted and returned %d",
(int) readbytes));
continue; /* Interrupted */
}
#endif
if (MyFlags & (MY_WME | MY_FAE | MY_FNABP))
{
if ((int) readbytes == -1)
my_error(EE_READ, MYF(ME_BELL+ME_WAITTANG),
my_filename(Filedes),my_errno);
else if (MyFlags & (MY_NABP | MY_FNABP))
my_error(EE_EOFERR, MYF(ME_BELL+ME_WAITTANG),
my_filename(Filedes),my_errno);
}
if ((int) readbytes == -1 ||
((MyFlags & (MY_FNABP | MY_NABP)) && !(MyFlags & MY_FULL_IO)))
DBUG_RETURN(MY_FILE_ERROR); /* Return with error */
if (readbytes > 0 && (MyFlags & MY_FULL_IO))
{
Buffer+= readbytes;
Count-= readbytes;
continue;
}
}
if (MyFlags & (MY_NABP | MY_FNABP))
readbytes= 0; /* Ok on read */
else if (MyFlags & MY_FULL_IO)
readbytes= save_count;
break;
}
DBUG_RETURN(readbytes);
} /* my_read */
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