VilhoRaatikka 4f3d746f4e MAX-157. Added support for hints in rwsplit router.
buffer.c: added memory release for hint of a GWBUF
hint.c: added bool hint_exists()
hint.h: added placeholder for hint type HINT_ROUTE_TO_ALL which doesn't have implementation yet.
filter/Makefile: fixed dependency issue
hintparser.c: added const char* token_get_keyword(), hint_parser:added NULL check, hint_next_token: fixed off-by-one bug
readwritesplit.h: added bitfield for hints' use, which includes route targets and flag for case where user hinted to route to named backend server.
readwritesplit.c: added function route_target_t get_route_target() for resolving route target based on 1) query type (from query_classifier) 2) transaction state (active/not) and 3) hints. Modified get_dcb, which is called in routeQuery to provide pointer to correct backend DCB. Now get_dcb also takes server unique name as a parameter if such a hint was found. for hints' use, which includes  enter the commit message for your changes.
2014-07-31 23:40:02 +03:00

70 lines
2.0 KiB
C

#ifndef _HINT_H
#define _HINT_H
/*
* This file is distributed as part of 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 SkySQL Ab 2014
*/
/**
* @file hint.h The generic hint data that may be attached to buffers
*
* @verbatim
* Revision History
*
* Date Who Description
* 10/07/14 Mark Riddoch Initial implementation
*
* @endverbatim
*/
#include <skygw_debug.h>
/**
* The types of hint that are supported by the generic hinting mechanism.
*/
typedef enum {
HINT_ROUTE_TO_MASTER = 1,
HINT_ROUTE_TO_SLAVE,
HINT_ROUTE_TO_NAMED_SERVER,
HINT_ROUTE_TO_UPTODATE_SERVER,
HINT_ROUTE_TO_ALL, /*< not implemented yet */
HINT_PARAMETER
} HINT_TYPE;
/**
* A generic hint.
*
* A hint has a type associated with it and may optionally have hint
* specific data.
* Multiple hints may be attached to a single buffer.
*/
typedef struct hint {
HINT_TYPE type; /*< The Type of hint */
void *data; /*< Type specific data */
void *value; /*< Parameter value for hint */
unsigned int dsize; /*< Size of the hint data */
struct hint *next; /*< Another hint for this buffer */
} HINT;
extern HINT *hint_alloc(HINT_TYPE, void *, unsigned int);
extern HINT *hint_create_parameter(HINT *, char *, char *);
extern HINT *hint_create_route(HINT *, HINT_TYPE, char *);
extern void hint_free(HINT *);
extern HINT *hint_dup(HINT *);
bool hint_exists(HINT **, HINT_TYPE);
#endif