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/*
Copyright (c) 2013 Monty Program Ab
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
*/
/*
a really minimal engine to test table discovery via sql statements.
See the archive engine if you're interested in real-life usable engine that
uses discovery via frm shipping.
*/
#include <mysql_version.h>
#include <handler.h>
#include <table.h>
static MYSQL_THDVAR_STR(statement, PLUGIN_VAR_MEMALLOC,
"The table name and the SQL statement to discover the next table",
NULL, NULL, 0);
static MYSQL_THDVAR_BOOL(write_frm, 0,
"Whether to cache discovered table metadata in frm files",
NULL, NULL, TRUE);
static struct st_mysql_sys_var *sysvars[] = {
MYSQL_SYSVAR(statement),
MYSQL_SYSVAR(write_frm),
NULL
};
class TSD_share : public Handler_share {
public:
THR_LOCK lock;
TSD_share()
{
thr_lock_init(&lock);
}
~TSD_share()
{
thr_lock_delete(&lock);
}
};
class ha_tsd: public handler
{
private:
THR_LOCK_DATA lock;
TSD_share *share;
TSD_share *get_share();
public:
ha_tsd(handlerton *hton, TABLE_SHARE *table_arg)
: handler(hton, table_arg) { }
ulonglong table_flags() const
{ // NO_TRANSACTIONS and everything that affects CREATE TABLE
return HA_NO_TRANSACTIONS | HA_CAN_GEOMETRY | HA_NULL_IN_KEY |
HA_CAN_INDEX_BLOBS | HA_AUTO_PART_KEY | HA_CAN_RTREEKEYS |
HA_CAN_FULLTEXT;
}
ulong index_flags(uint inx, uint part, bool all_parts) const { return 0; }
THR_LOCK_DATA **store_lock(THD *thd, THR_LOCK_DATA **to,
enum thr_lock_type lock_type)
{
if (lock_type != TL_IGNORE && lock.type == TL_UNLOCK)
lock.type = lock_type;
*to ++= &lock;
return to;
}
int rnd_init(bool scan) { return 0; }
int rnd_next(unsigned char *buf) { return HA_ERR_END_OF_FILE; }
void position(const uchar *record) { }
int rnd_pos(uchar *buf, uchar *pos) { return HA_ERR_END_OF_FILE; }
int info(uint flag) { return 0; }
uint max_supported_keys() const { return 16; }
int create(const char *name, TABLE *table_arg,
HA_CREATE_INFO *create_info) { return HA_ERR_WRONG_COMMAND; }
int open(const char *name, int mode, uint test_if_locked);
int close(void);
};
TSD_share *ha_tsd::get_share()
{
TSD_share *tmp_share;
lock_shared_ha_data();
if (!(tmp_share= static_cast<TSD_share*>(get_ha_share_ptr())))
{
tmp_share= new TSD_share;
if (!tmp_share)
goto err;
set_ha_share_ptr(static_cast<Handler_share*>(tmp_share));
}
err:
unlock_shared_ha_data();
return tmp_share;
}
int ha_tsd::open(const char *name, int mode, uint test_if_locked)
{
if (!(share= get_share()))
return HA_ERR_OUT_OF_MEM;
thr_lock_data_init(&share->lock,&lock,NULL);
return 0;
}
int ha_tsd::close(void)
{
return 0;
}
static handler *create_handler(handlerton *hton, TABLE_SHARE *table,
MEM_ROOT *mem_root)
{
return new (mem_root) ha_tsd(hton, table);
}
static int discover_table(handlerton *hton, THD* thd, TABLE_SHARE *share)
{
const char *sql= THDVAR(thd, statement);
// the table is discovered if sql starts from "table_name:"
if (!sql ||
strncmp(sql, share->table_name.str, share->table_name.length) ||
sql[share->table_name.length] != ':')
return HA_ERR_NO_SUCH_TABLE;
sql+= share->table_name.length + 1;
return share->init_from_sql_statement_string(thd, THDVAR(thd, write_frm),
sql, strlen(sql));
}
static int init(void *p)
{
handlerton *hton = (handlerton *)p;
hton->create = create_handler;
hton->discover_table = discover_table;
return 0;
}
struct st_mysql_storage_engine descriptor =
{ MYSQL_HANDLERTON_INTERFACE_VERSION };
maria_declare_plugin(test_sql_discovery)
{
MYSQL_STORAGE_ENGINE_PLUGIN,
&descriptor,
"TEST_SQL_DISCOVERY",
"Sergei Golubchik",
"Minimal engine to test table discovery via sql statements",
PLUGIN_LICENSE_GPL,
init,
NULL,
0x0001,
NULL,
sysvars,
"0.1",
MariaDB_PLUGIN_MATURITY_EXPERIMENTAL
}
maria_declare_plugin_end;
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