~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/bind.hpp>

#include <drizzled/identifier.h>

#include <drizzled/error.h>

#include <drizzled/catalog.h>

#include <drizzled/plugin/catalog.h>

#include <boost/unordered_map.hpp>

#include <boost/thread/mutex.hpp>

namespace drizzled {

namespace catalog  {

class Cache

{

public:

  static size_t size()

  {

    return cache.size();

  }

  static Instance::shared_ptr find(const identifier::Catalog&, error_t&);

  static bool exist(const identifier::Catalog&);

  static bool erase(const identifier::Catalog&, error_t&);

  static bool insert(const identifier::Catalog&, Instance::shared_ptr, error_t&);

  static bool lock(const identifier::Catalog&, error_t&);

  static bool unlock(const identifier::Catalog&, error_t&);

  static void copy(catalog::Instance::vector&);

  typedef boost::unordered_map<identifier::Catalog, catalog::Instance::shared_ptr> unordered_map;

  static unordered_map cache;

  static boost::mutex _mutex;

};

namespace lock {

class Erase

{

  bool _locked;

  const identifier::Catalog &identifier;

  error_t error;

public:

  Erase(const identifier::Catalog &identifier_arg) :

    _locked(false),

    identifier(identifier_arg)

  {

    init();

  }

  bool locked () const

  {

    return _locked;

  }

  ~Erase()

  {

    if (_locked)

    {

      if (not catalog::Cache::unlock(identifier, error))

      {

        my_error(error, identifier);

        assert(0);

      }

    }

  }

private:

  void init()

  {

    // We insert a lock into the cache, if this fails we bail.

    if (not catalog::Cache::lock(identifier, error))

    {

      assert(0);

      return;

    }

    _locked= true;

  }

};

class Create

{

  bool _locked;

  const identifier::Catalog &identifier;

  error_t error;

public:

  Create(const identifier::Catalog &identifier_arg) :

    _locked(false),

    identifier(identifier_arg)

  {

    init();

  }

  bool locked () const

  {

    return _locked;

  }

  ~Create()

  {

    if (_locked)

    {

      if (not catalog::Cache::unlock(identifier, error))

      {

        my_error(error, identifier);

        assert(0);

      }

    }

  }

private:

  void init()

  {

    // We insert a lock into the cache, if this fails we bail.

    if (not catalog::Cache::lock(identifier, error))

    {

      my_error(error, identifier);

      return;

    }

    _locked= true;

  }

};

} /* namespace lock */

} /* namespace catalog */

} /* namespace drizzled */