1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
84
85
86
87
88
89
90
91
92
93
94
95
96
97
98
99
100
101
102
103
104
105
106
107
108
109
110
111
112
113
114
115
116
117
118
119
120
121
122
123
124
125
126
127
128
129
130
131
132
133
134
135
136
137
138
139
140
141
142
143
144
145
146
147
148
149
150
151
152
153
154
155
156
157
158
159
160
161
162
163
164
165
166
167
168
169
170
171
172
173
174
175
176
177
178
179
180
181
182
183
184
185
186
187
|
/*
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 02110-1335 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 <my_global.h>
#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 drop_table(handlerton *hton, const char *path)
{
const char *name= strrchr(path, FN_LIBCHAR)+1;
const char *sql= THDVAR(current_thd, statement);
return !sql || strncmp(sql, name, strlen(name)) || sql[strlen(name)] != ':'
? ENOENT : 0;
}
static int init(void *p)
{
handlerton *hton = (handlerton *)p;
hton->create = create_handler;
hton->discover_table = discover_table;
hton->drop_table= drop_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;
|
