~drizzle-trunk/drizzle/development

/* -*- mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; -*-

 *  vim:expandtab:shiftwidth=2:tabstop=2:smarttab:

 *

 *  Copyright (C) 2010 Brian Aker

 *

 *  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., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA

 */

#include <config.h>

#include <sys/types.h>

#include <sys/stat.h>

#include <fcntl.h>

#include <drizzled/identifier.h>

#include <drizzled/sql_base.h>

#include <drizzled/set_var.h>

#include <drizzled/table/unused.h>

namespace drizzled

{

extern uint64_t table_cache_size;

namespace table

{

UnusedTables &getUnused(void)

{

  static UnusedTables unused_tables;

  return unused_tables;

}

void UnusedTables::cull()

{

  /* Free cache if too big */

  while (cached_open_tables() > table_cache_size && getTable())

    remove_table(getTable());

}

void UnusedTables::cullByVersion()

{

  while (getTable() && not getTable()->getShare()->getVersion())

    remove_table(getTable());

}

void UnusedTables::link(Concurrent *table)

{

  if (getTable())

  {

    table->setNext(getTable());		/* Link in last */

    table->setPrev(getTable()->getPrev());

    getTable()->setPrev(table);

    table->getPrev()->setNext(table);

  }

  else

  {

    table->setPrev(setTable(table));

    table->setNext(table->getPrev());

    assert(table->getNext() == table && table->getPrev() == table);

  }

}

void UnusedTables::unlink(Concurrent *table)

{

  table->unlink();

  /* Unlink the table from "unused_tables" list. */

  if (table == getTable())

  {  // First unused

    setTable(getTable()->getNext()); // Remove from link

    if (table == getTable())

      setTable(NULL);

  }

}

/* move table first in unused links */

void UnusedTables::relink(Concurrent *table)

{

  if (table != getTable())

  {

    table->unlink();

    table->setNext(getTable());			/* Link in unused tables */

    table->setPrev(getTable()->getPrev());

    getTable()->getPrev()->setNext(table);

    getTable()->setPrev(table);

    setTable(table);

  }

}

void UnusedTables::clear()

{

  while (getTable())

    remove_table(getTable());

}

} /* namespace table */

} /* namespace drizzled */