~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

 */

#pragma once

#include <boost/thread/mutex.hpp>

#include <boost/make_shared.hpp>

#include <drizzled/message/catalog.h>

namespace drizzled {

namespace catalog {

class Instance

{

  Instance() :

    _locked(false),

    _lock_id(0)

  { };

  bool _locked;

  drizzled::session_id_t _lock_id;

  message::catalog::shared_ptr _message;

  mutable boost::mutex _schema_lock;

  mutable boost::mutex _system_variable_lock;

public:

  typedef boost::shared_ptr<Instance> shared_ptr;

  typedef std::vector<shared_ptr> vector;

  typedef const Instance* const_pointer;

  typedef const Instance& const_reference;

  typedef Instance& reference;

  Instance(message::catalog::shared_ptr &message_arg)

  {

    _message= message_arg;

  };

  Instance(const message::catalog::shared_ptr &message_arg)

  {

    _message= message_arg;

  };

  static shared_ptr make_shared(message::catalog::shared_ptr &message_arg)

  {

    assert(not message_arg->name().empty());

    return boost::make_shared<Instance>(message_arg);

  };

  static shared_ptr make_shared(const identifier::Catalog &identifier)

  {

    drizzled::message::catalog::shared_ptr new_message= drizzled::message::catalog::make_shared(identifier);

    assert(not new_message->name().empty());

    return boost::make_shared<Instance>(new_message);

  }

  const std::string &getName() const

  {

    assert(_message);

    return _message->name();

  }

  const std::string &name() const

  {

    assert(_message);

    return _message->name();

  }

  message::catalog::shared_ptr message() const

  {

    return _message;

  }

  bool locked() const

  {

    return _locked;

  }

  bool lock(drizzled::session_id_t id)

  {

    if (_locked and _lock_id == id)

    {

      assert(0); // We shouldn't support recursion

      return true;

    }

    else if (_locked)

    {

      return false;

    }

    _locked= true;

    _lock_id= id;

    return true;

  }

  bool unlock(drizzled::session_id_t id)

  {

    if (_locked and _lock_id == id)

    {

      _locked= false;

      _lock_id= 0;

      return true;

    }

    return false;

  }

  boost::mutex &schemaLock()

  {

    return _schema_lock;

  }

  boost::mutex &systemVariableLock()

  {

    return _system_variable_lock;

  }

};

} /* namespace catalog */

} /* namespace drizzled */