~drizzle-trunk/drizzle/development

/* 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 <drizzled/server_includes.h>

#include <drizzled/session.h>

/**

  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, unsigned char *Buffer, size_t)

{

  ulong read_length;

  NET *net= &(current_session)->net;

  if (!info->end_of_file)

    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;

    return(1);

  }

  if (read_length == 0)

  {

    info->end_of_file= 0;			/* End of file from client */

    return(1);

  }

  /* to set up stuff for my_b_get (no _) */

  info->read_end = (info->read_pos = (unsigned char*) 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++;

  return(0);

}