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/* Copyright (C) 2000-2004 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 */
/**
@file
@details
Caching of files with only does (sequential) read or writes of fixed-
length records. A read isn't allowed to go over file-length. A read is ok
if it ends at file-length and next read can try to read after file-length
(and get a EOF-error).
Possibly use of asyncronic io.
macros for read and writes for faster io.
Used instead of FILE when reading or writing whole files.
This will make mf_rec_cache obsolete.
One can change info->pos_in_file to a higher value to skip bytes in file if
also info->rc_pos is set to info->rc_end.
If called through open_cached_file(), then the temporary file will
only be created if a write exeeds the file buffer or if one calls
flush_io_cache().
*/
#include "sql_priv.h"
#include "sql_class.h" // THD
#ifdef HAVE_REPLICATION
extern "C" {
/**
Read buffered from the net.
@retval
1 if can't read requested characters
@retval
0 if record read
*/
int _my_b_net_read(register IO_CACHE *info, uchar *Buffer,
size_t Count __attribute__((unused)))
{
ulong read_length;
NET *net= &(current_thd)->net;
DBUG_ENTER("_my_b_net_read");
if (!info->end_of_file)
DBUG_RETURN(1); /* because my_b_get (no _) takes 1 byte at a time */
read_length=my_net_read(net);
if (read_length == packet_error)
{
info->error= -1;
DBUG_RETURN(1);
}
if (read_length == 0)
{
info->end_of_file= 0; /* End of file from client */
DBUG_RETURN(1);
}
/* to set up stuff for my_b_get (no _) */
info->read_end = (info->read_pos = (uchar*) net->read_pos) + read_length;
Buffer[0] = info->read_pos[0]; /* length is always 1 */
/*
info->request_pos is used by log_loaded_block() to know the size
of the current block.
info->pos_in_file is used by log_loaded_block() too.
*/
info->pos_in_file+= read_length;
info->request_pos=info->read_pos;
info->read_pos++;
DBUG_RETURN(0);
}
} /* extern "C" */
#endif /* HAVE_REPLICATION */
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