MaxScale/server/modules/include/readconnection.h

77 lines
2.4 KiB
C

#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