VilhoRaatikka 6d2b38d4b6 Complementary fix to #694,http://bugs.mariadb.com/show_bug.cgi?id=694
RWSplit router handles query processing errors that happened in router by sending parse error reply to client. routeQuery fails only when backend has failed.
2015-01-17 22:40:52 +02:00

111 lines
3.7 KiB
C

#ifndef _ROUTER_H
#define _ROUTER_H
/*
* This file is distributed as part of the MariaDB Corporation MaxScale. 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 MariaDB Corporation Ab 2013-2014
*/
/**
* @file router.h - The query router interface mechanisms
*
* Revision History
*
* Date Who Description
* 14/06/2013 Mark Riddoch Initial implementation
* 26/06/2013 Mark Riddoch Addition of router options
* and the diagnostic entry point
* 15/07/2013 Massimiliano Pinto Added clientReply entry point
* 16/07/2013 Massimiliano Pinto Added router commands values
* 22/10/2013 Massimiliano Pinto Added router errorReply entry point
*
*/
#include <service.h>
#include <session.h>
#include <buffer.h>
#include <stdint.h>
/**
* The ROUTER handle points to module specific data, so the best we can do
* is to make it a void * externally.
*/
typedef void *ROUTER;
typedef enum error_action {
ERRACT_NEW_CONNECTION = 0x001,
ERRACT_REPLY_CLIENT = 0x002,
ERRACT_RESET = 0x004
} error_action_t;
/**
* @verbatim
* The "module object" structure for a query router module
*
* The entry points are:
* createInstance Called by the service to create a new
* instance of the query router
* newSession Called to create a new user session
* within the query router
* closeSession Called when a session is closed
* routeQuery Called on each query that requires
* routing
* diagnostics Called to force the router to print
* diagnostic output
* clientReply Called to reply to client the data from one or all backends
* errorReply Called to reply to client errors with optional closeSession or
* make a request for a new backend connection
*
* @endverbatim
*
* @see load_module
*/
typedef struct router_object {
ROUTER *(*createInstance)(SERVICE *service, char **options);
void *(*newSession)(ROUTER *instance, SESSION *session);
void (*closeSession)(ROUTER *instance, void *router_session);
void (*freeSession)(ROUTER *instance, void *router_session);
int (*routeQuery)(ROUTER *instance, void *router_session, GWBUF *queue);
void (*diagnostics)(ROUTER *instance, DCB *dcb);
void (*clientReply)(ROUTER* instance, void* router_session, GWBUF* queue, DCB *backend_dcb);
void (*handleError)(
ROUTER* instance,
void* router_session,
GWBUF* errmsgbuf,
DCB* backend_dcb,
error_action_t action,
bool* succp);
uint8_t (*getCapabilities)(ROUTER *instance, void* router_session);
} ROUTER_OBJECT;
/**
* The router module API version. Any change that changes the router API
* must update these versions numbers in accordance with the rules in
* modinfo.h.
*/
#define ROUTER_VERSION { 1, 0, 0 }
/**
* Router capability type. Indicates what kind of input router accepts.
*/
typedef enum router_capability_t {
RCAP_TYPE_UNDEFINED = 0x00,
RCAP_TYPE_STMT_INPUT = 0x01, /*< statement per buffer */
RCAP_TYPE_PACKET_INPUT = 0x02 /*< data as it was read from DCB */
} router_capability_t;
#endif