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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; 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 02110-1301 USA */
#include <config.h>
#include <drizzled/internal/my_sys.h>
#include <drizzled/error.h>
#include <errno.h>
namespace drizzled
{
namespace internal
{
/*
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.
*/
size_t my_read(int Filedes, unsigned char *Buffer, size_t Count, myf MyFlags)
{
size_t readbytes, save_count;
save_count= Count;
for (;;)
{
errno= 0; /* Linux doesn't reset this */
if ((readbytes= read(Filedes, Buffer, Count)) != Count)
{
errno= errno ? errno : -1;
if ((readbytes == 0 || (int) readbytes == -1) && errno == EINTR)
{
continue; /* Interrupted */
}
if (MyFlags & (MY_WME | MY_FAE | MY_FNABP))
{
if (readbytes == (size_t) -1)
my_error(EE_READ, MYF(ME_BELL+ME_WAITTANG),
"unknown", errno);
else if (MyFlags & (MY_NABP | MY_FNABP))
my_error(EE_EOFERR, MYF(ME_BELL+ME_WAITTANG),
"unknown", errno);
}
if (readbytes == (size_t) -1 ||
((MyFlags & (MY_FNABP | MY_NABP)) && !(MyFlags & MY_FULL_IO)))
return(MY_FILE_ERROR); /* Return with error */
if (readbytes != (size_t) -1 && (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;
}
return(readbytes);
} /* my_read */
} /* namespace internal */
} /* namespace drizzled */
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