~drizzle-trunk/drizzle/development

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

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

 *

 *  Copyright (C) 2008 Sun Microsystems, Inc.

 *

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

 */

#pragma once

#include <boost/foreach.hpp>

#include <drizzled/plugin/plugin.h>

#include <drizzled/atomics.h>

#include <vector>

#include <drizzled/visibility.h>

namespace drizzled {

namespace plugin {

typedef std::vector<Listen *> ListenVector;

typedef std::pair<std::string*, drizzled::atomic<uint64_t>*> ListenCounter;

/**

 * This class is used by client plugins to provide and manage the listening

 * interface for new client instances.

 */

class DRIZZLED_API Listen : public Plugin

{

protected:

  std::vector<ListenCounter*> counters;

public:

  explicit Listen(std::string name_arg)

    : Plugin(name_arg, "Listen")

  {}

  virtual ~Listen()

  {

    BOOST_FOREACH(ListenCounter* counter, counters)

    {

      delete counter->first;

      delete counter;

    }

  }

  static ListenVector &getListenProtocols();

  std::vector<ListenCounter*>& getListenCounters()

  {

    return counters;

  }

  /**

   * This provides a list of file descriptors to watch that will trigger new

   * Client instances. When activity is detected on one of the returned file

   * descriptors, getClient will be called with the file descriptor.

   * @fds[out] Vector of file descriptors to watch for activity.

   * @retval true on failure, false on success.

   */

  virtual bool getFileDescriptors(std::vector<int> &fds)= 0;

  /**

   * This provides a new Client object that can be used by a Session.

   * @param[in] fd File descriptor that had activity.

   */

  virtual plugin::Client *getClient(int fd)= 0;

  /**

   * Add a new Listen object to the list of listeners we manage.

   */

  static bool addPlugin(Listen*);

  /**

   * Remove a Listen object from the list of listeners we manage.

   */

  static void removePlugin(Listen*);

  /**

   * Setup all configured listen plugins.

   */

  static bool setup(void);

  /**

   * Accept a new connection (Client object) on one of the configured

   * listener interfaces.

   */

  static plugin::Client *getClient();

  /**

   * Some internal functions drizzled require a temporary Client object to

   * create a valid session object, this just returns a dummy client object.

   */

  static plugin::Client *getNullClient();

  /**

   * Shutdown and cleanup listen loop for server shutdown.

   */

  static void shutdown();

};

} /* namespace plugin */

} /* namespace drizzled */