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/* -*- mode: c++; c-basic-offset: 2; indent-tabs-mode: nil; -*-
* vim:expandtab:shiftwidth=2:tabstop=2:smarttab:
*
* Copyright (C) 2008 Sun Microsystems
*
* This program 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 of the License.
*
* 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 St, Fifth Floor, Boston, MA 02110-1301 USA
*/
#ifndef DRIZZLED_HANDLERTON_H
#define DRIZZLED_HANDLERTON_H
#include <stdint.h>
#include <drizzled/definitions.h>
#include <drizzled/sql_plugin.h>
class TableList;
class Session;
class XID;
class handler;
typedef struct st_mysql_lex_string LEX_STRING;
typedef struct st_table_share TABLE_SHARE;
typedef bool (stat_print_fn)(Session *session, const char *type, uint32_t type_len,
const char *file, uint32_t file_len,
const char *status, uint32_t status_len);
enum ha_stat_type { HA_ENGINE_STATUS, HA_ENGINE_LOGS, HA_ENGINE_MUTEX };
/*
handlerton is a singleton structure - one instance per storage engine -
to provide access to storage engine functionality that works on the
"global" level (unlike handler class that works on a per-table basis)
usually handlerton instance is defined statically in ha_xxx.cc as
static handlerton { ... } xxx_hton;
savepoint_*, prepare, recover, and *_by_xid pointers can be 0.
*/
struct handlerton
{
/*
Historical marker for if the engine is available of not
*/
SHOW_COMP_OPTION state;
/*
Historical number used for frm file to determine the correct storage engine.
This is going away and new engines will just use "name" for this.
*/
enum legacy_db_type db_type;
/*
each storage engine has it's own memory area (actually a pointer)
in the session, for storing per-connection information.
It is accessed as
session->ha_data[xxx_hton.slot]
slot number is initialized by MySQL after xxx_init() is called.
*/
uint32_t slot;
/*
to store per-savepoint data storage engine is provided with an area
of a requested size (0 is ok here).
savepoint_offset must be initialized statically to the size of
the needed memory to store per-savepoint information.
After xxx_init it is changed to be an offset to savepoint storage
area and need not be used by storage engine.
see binlog_hton and binlog_savepoint_set/rollback for an example.
*/
uint32_t savepoint_offset;
/*
handlerton methods:
close_connection is only called if
session->ha_data[xxx_hton.slot] is non-zero, so even if you don't need
this storage area - set it to something, so that MySQL would know
this storage engine was accessed in this connection
*/
int (*close_connection)(handlerton *hton, Session *session);
/*
sv points to an uninitialized storage area of requested size
(see savepoint_offset description)
*/
int (*savepoint_set)(handlerton *hton, Session *session, void *sv);
/*
sv points to a storage area, that was earlier passed
to the savepoint_set call
*/
int (*savepoint_rollback)(handlerton *hton, Session *session, void *sv);
int (*savepoint_release)(handlerton *hton, Session *session, void *sv);
/*
'all' is true if it's a real commit, that makes persistent changes
'all' is false if it's not in fact a commit but an end of the
statement that is part of the transaction.
NOTE 'all' is also false in auto-commit mode where 'end of statement'
and 'real commit' mean the same event.
*/
int (*commit)(handlerton *hton, Session *session, bool all);
int (*rollback)(handlerton *hton, Session *session, bool all);
int (*prepare)(handlerton *hton, Session *session, bool all);
int (*recover)(handlerton *hton, XID *xid_list, uint32_t len);
int (*commit_by_xid)(handlerton *hton, XID *xid);
int (*rollback_by_xid)(handlerton *hton, XID *xid);
void *(*create_cursor_read_view)(handlerton *hton, Session *session);
void (*set_cursor_read_view)(handlerton *hton, Session *session, void *read_view);
void (*close_cursor_read_view)(handlerton *hton, Session *session, void *read_view);
handler *(*create)(handlerton *hton, TABLE_SHARE *table, MEM_ROOT *mem_root);
void (*drop_database)(handlerton *hton, char* path);
int (*start_consistent_snapshot)(handlerton *hton, Session *session);
bool (*flush_logs)(handlerton *hton);
bool (*show_status)(handlerton *hton, Session *session, stat_print_fn *print, enum ha_stat_type stat);
int (*fill_files_table)(handlerton *hton, Session *session,
TableList *tables,
class Item *cond);
uint32_t flags; /* global handler flags */
int (*release_temporary_latches)(handlerton *hton, Session *session);
int (*discover)(handlerton *hton, Session* session, const char *db,
const char *name,
unsigned char **frmblob,
size_t *frmlen);
int (*table_exists_in_engine)(handlerton *hton, Session* session, const char *db,
const char *name);
uint32_t license; /* Flag for Engine License */
void *data; /* Location for engines to keep personal structures */
};
/* lookups */
handlerton *ha_default_handlerton(Session *session);
plugin_ref ha_resolve_by_name(Session *session, const LEX_STRING *name);
plugin_ref ha_lock_engine(Session *session, handlerton *hton);
handlerton *ha_resolve_by_legacy_type(Session *session,
enum legacy_db_type db_type);
handler *get_new_handler(TABLE_SHARE *share, MEM_ROOT *alloc,
handlerton *db_type);
handlerton *ha_checktype(Session *session, enum legacy_db_type database_type,
bool no_substitute, bool report_error);
enum legacy_db_type ha_legacy_type(const handlerton *db_type);
const char *ha_resolve_storage_engine_name(const handlerton *db_type);
bool ha_check_storage_engine_flag(const handlerton *db_type, uint32_t flag);
bool ha_storage_engine_is_enabled(const handlerton *db_type);
LEX_STRING *ha_storage_engine_name(const handlerton *hton);
#endif /* DRIZZLED_HANDLERTON_H */
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