#ifndef _READCONNECTION_H
#define _READCONNECTION_H
/*
 * This file is distributed as part of the SkySQL Gateway.  It 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.
 *
 * 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 Street, Fifth Floor, Boston, MA 02110-1301 USA.
 *
 * Copyright SkySQL Ab 2013
 */

/**
 * @file readconnection.h - The read connection balancing query module heder file
 *
 * @verbatim
 * Revision History
 *
 * Date		Who		Description
 * 14/06/13	Mark Riddoch	Initial implementation
 *
 * @endverbatim
 */
#include <dcb.h>

/**
 * Internal structure used to define the set of backend servers we are routing
 * connections to. This provides the storage for routing module specific data
 * that is required for each of the backend servers.
 */
typedef struct backend {
	SERVER		*server;	           /**< The server itself */
	int		current_connection_count;  /**< Number of connections to the server */
} BACKEND;

/**
 * The client session structure used within this router.
 */
typedef struct client_session {
	BACKEND		*backend;	/**< Backend used by the client session */
	DCB		*dcb;		/**< DCB Connection to the backend */
	struct client_session
			*next;
} CLIENT_SESSION;

/**
 * The statistics for this router instance
 */
typedef struct {
	int		n_sessions;	/**< Number sessions created */
	int		n_queries;	/**< Number of queries forwarded */
} ROUTER_STATS;


/**
 * The per instance data for the router.
 */
typedef struct instance {
	SERVICE		*service;	/**< Pointer to the service using this router */
	CLIENT_SESSION	*connections;	/**< Link list of all the client connections */
	SPINLOCK	lock;		/**< Spinlock for the instance data */
	BACKEND		**servers;	/**< The set of backend servers for this instance */
	unsigned int	bitmask;	/**< Bitmask to apply to server->status */
	unsigned int	bitvalue;	/**< Required value of server->status */
	ROUTER_STATS	stats;		/**< Statistics for this router */
	struct instance	*next;
} INSTANCE;
#endif