/* Copyright (C) 2005 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 */


#ifdef __GNUC__
#pragma implementation        // gcc: Class implementation
#endif

#include <mysql_priv.h>

#ifdef HAVE_BLACKHOLE_DB
#include "ha_blackhole.h"


const char **ha_blackhole::bas_ext() const
{ 
  static const char *ext[]= { NullS }; 
  return ext; 
}

int ha_blackhole::open(const char *name, int mode, uint test_if_locked)
{
  DBUG_ENTER("ha_blackhole::open");
  thr_lock_init(&thr_lock);
  thr_lock_data_init(&thr_lock,&lock,NULL);
  DBUG_RETURN(0);
}

int ha_blackhole::close(void)
{
  DBUG_ENTER("ha_blackhole::close");
  thr_lock_delete(&thr_lock);
  DBUG_RETURN(0);
}

int ha_blackhole::create(const char *name, TABLE *table_arg,
                       HA_CREATE_INFO *create_info)
{
  DBUG_ENTER("ha_blackhole::create");
  DBUG_RETURN(0);
}

const char *ha_blackhole::index_type(uint key_number)
{
  DBUG_ENTER("ha_blackhole::index_type");
  DBUG_RETURN((table->key_info[key_number].flags & HA_FULLTEXT) ? 
	  "FULLTEXT" :
	  (table->key_info[key_number].flags & HA_SPATIAL) ?
	  "SPATIAL" :
	  (table->key_info[key_number].algorithm == HA_KEY_ALG_RTREE) ?
	  "RTREE" :
	  "BTREE");
}

int ha_blackhole::write_row(byte * buf)
{
  DBUG_ENTER("ha_blackhole::write_row");
  DBUG_RETURN(0);
}

int ha_blackhole::rnd_init(bool scan)
{
  DBUG_ENTER("ha_blackhole::rnd_init");
  DBUG_RETURN(0);
}


int ha_blackhole::rnd_next(byte *buf)
{
  DBUG_ENTER("ha_blackhole::rnd_next");
  DBUG_RETURN(HA_ERR_END_OF_FILE);
}


int ha_blackhole::rnd_pos(byte * buf, byte *pos)
{
  DBUG_ENTER("ha_blackhole::rnd_pos");
  DBUG_RETURN(0);
}


void ha_blackhole::position(const byte *record)
{
  DBUG_ENTER("ha_blackhole::position");
  DBUG_VOID_RETURN;
}


void ha_blackhole::info(uint flag)
{
  DBUG_ENTER("ha_blackhole::info");

  records= 0;
  deleted= 0;
  errkey= 0;
  mean_rec_length= 0;
  data_file_length= 0;
  index_file_length= 0;
  max_data_file_length= 0;
  delete_length= 0;
  if (flag & HA_STATUS_AUTO)
    auto_increment_value= 1;
  DBUG_VOID_RETURN;
}

int ha_blackhole::external_lock(THD *thd, int lock_type)
{
  DBUG_ENTER("ha_blackhole::external_lock");
  DBUG_RETURN(0);
}


THR_LOCK_DATA **ha_blackhole::store_lock(THD *thd,
                                       THR_LOCK_DATA **to,
                                       enum thr_lock_type lock_type)
{
  if (lock_type != TL_IGNORE && lock.type == TL_UNLOCK) 
  {
    /* 
      Here is where we get into the guts of a row level lock.
      If TL_UNLOCK is set 
      If we are not doing a LOCK TABLE or DISCARD/IMPORT
      TABLESPACE, then allow multiple writers 
    */

    if ((lock_type >= TL_WRITE_CONCURRENT_INSERT &&
         lock_type <= TL_WRITE) && !thd->in_lock_tables
        && !thd->tablespace_op)
      lock_type = TL_WRITE_ALLOW_WRITE;

    /* 
      In queries of type INSERT INTO t1 SELECT ... FROM t2 ...
      MySQL would use the lock TL_READ_NO_INSERT on t2, and that
      would conflict with TL_WRITE_ALLOW_WRITE, blocking all inserts
      to t2. Convert the lock to a normal read lock to allow
      concurrent inserts to t2. 
    */

    if (lock_type == TL_READ_NO_INSERT && !thd->in_lock_tables) 
      lock_type = TL_READ;

    lock.type=lock_type;
  }

  *to++= &lock;

  return to;
}


#endif /* HAVE_BLACKHOLE_DB */