2015-11-30 13:40:11 +02:00

123 lines
4.5 KiB
C

#ifndef _FILTER_H
#define _FILTER_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 2014
*/
/**
* @file filter.h - The filter interface mechanisms
*
* Revision History
*
* Date Who Description
* 27/05/2014 Mark Riddoch Initial implementation
*
*/
#include <dcb.h>
#include <session.h>
#include <buffer.h>
#include <stdint.h>
/**
* The FILTER handle points to module specific data, so the best we can do
* is to make it a void * externally.
*/
typedef void *FILTER;
/**
* The structure used to pass name, value pairs to the filter instances
*/
typedef struct
{
char *name; /**< Name of the parameter */
char *value; /**< Value of the parameter */
} FILTER_PARAMETER;
/**
* @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 filter
* newSession Called to create a new user session
* within the filter
* closeSession Called when a session is closed
* freeSession Called when a session is freed
* setDownstream Sets the downstream component of the
* filter pipline
* routeQuery Called on each query that requires
* routing
* clientReply Called for each reply packet
* diagnostics Called to force the filter to print
* diagnostic output
*
* @endverbatim
*
* @see load_module
*/
typedef struct filter_object
{
FILTER *(*createInstance)(char **options, FILTER_PARAMETER **);
void *(*newSession)(FILTER *instance, SESSION *session);
void (*closeSession)(FILTER *instance, void *fsession);
void (*freeSession)(FILTER *instance, void *fsession);
void (*setDownstream)(FILTER *instance, void *fsession, DOWNSTREAM *downstream);
void (*setUpstream)(FILTER *instance, void *fsession, UPSTREAM *downstream);
int (*routeQuery)(FILTER *instance, void *fsession, GWBUF *queue);
int (*clientReply)(FILTER *instance, void *fsession, GWBUF *queue);
void (*diagnostics)(FILTER *instance, void *fsession, DCB *dcb);
} FILTER_OBJECT;
/**
* The filter API version. If the FILTER_OBJECT structure or the filter API
* is changed these values must be updated in line with the rules in the
* file modinfo.h.
*/
#define FILTER_VERSION {1, 1, 0}
/**
* The definition of a filter from the configuration file.
* This is basically the link between a plugin to load and the
* optons to pass to that plugin.
*/
typedef struct filter_def
{
char *name; /**< The Filter name */
char *module; /**< The module to load */
char **options; /**< The options set for this filter */
FILTER_PARAMETER **parameters; /**< The filter parameters */
FILTER filter; /**< The runtime filter */
FILTER_OBJECT *obj; /**< The "MODULE_OBJECT" for the filter */
SPINLOCK spin; /**< Spinlock to protect the filter definition */
struct filter_def *next; /**< Next filter in the chain of all filters */
} FILTER_DEF;
FILTER_DEF *filter_alloc(char *, char *);
void filter_free(FILTER_DEF *);
bool filter_load(FILTER_DEF* filter);
FILTER_DEF *filter_find(char *);
void filterAddOption(FILTER_DEF *, char *);
void filterAddParameter(FILTER_DEF *, char *, char *);
DOWNSTREAM *filterApply(FILTER_DEF *, SESSION *, DOWNSTREAM *);
UPSTREAM *filterUpstream(FILTER_DEF *, void *, UPSTREAM *);
int filter_standard_parameter(char *);
void dprintAllFilters(DCB *);
void dprintFilter(DCB *, FILTER_DEF *);
void dListFilters(DCB *);
#endif