1/*
2 Copyright (c) 2013 Monty Program Ab
3
4 This program is free software; you can redistribute it and/or
5 modify it under the terms of the GNU General Public License
6 as published by the Free Software Foundation; version 2 of
7 the License.
8
9 This program is distributed in the hope that it will be useful,
10 but WITHOUT ANY WARRANTY; without even the implied warranty of
11 MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
12 GNU General Public License for more details.
13
14 You should have received a copy of the GNU General Public License
15 along with this program; if not, write to the Free Software
16 Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA 02110-1301 USA
17*/
18
19/*
20 a really minimal engine to test table discovery via sql statements.
21 See the archive engine if you're interested in real-life usable engine that
22 uses discovery via frm shipping.
23*/
24
25#include <my_global.h>
26#include <mysql_version.h>
27#include <handler.h>
28#include <table.h>
29
30static MYSQL_THDVAR_STR(statement, PLUGIN_VAR_MEMALLOC,
31 "The table name and the SQL statement to discover the next table",
32 NULL, NULL, 0);
33
34static MYSQL_THDVAR_BOOL(write_frm, 0,
35 "Whether to cache discovered table metadata in frm files",
36 NULL, NULL, TRUE);
37
38static struct st_mysql_sys_var *sysvars[] = {
39 MYSQL_SYSVAR(statement),
40 MYSQL_SYSVAR(write_frm),
41 NULL
42};
43
44class TSD_share : public Handler_share {
45public:
46 THR_LOCK lock;
47 TSD_share()
48 {
49 thr_lock_init(&lock);
50 }
51 ~TSD_share()
52 {
53 thr_lock_delete(&lock);
54 }
55};
56
57class ha_tsd: public handler
58{
59private:
60 THR_LOCK_DATA lock;
61 TSD_share *share;
62 TSD_share *get_share();
63
64public:
65 ha_tsd(handlerton *hton, TABLE_SHARE *table_arg)
66 : handler(hton, table_arg) { }
67 ulonglong table_flags() const
68 { // NO_TRANSACTIONS and everything that affects CREATE TABLE
69 return HA_NO_TRANSACTIONS | HA_CAN_GEOMETRY | HA_NULL_IN_KEY |
70 HA_CAN_INDEX_BLOBS | HA_AUTO_PART_KEY | HA_CAN_RTREEKEYS |
71 HA_CAN_FULLTEXT;
72 }
73
74 ulong index_flags(uint inx, uint part, bool all_parts) const { return 0; }
75
76 THR_LOCK_DATA **store_lock(THD *thd, THR_LOCK_DATA **to,
77 enum thr_lock_type lock_type)
78 {
79 if (lock_type != TL_IGNORE && lock.type == TL_UNLOCK)
80 lock.type = lock_type;
81 *to ++= &lock;
82 return to;
83 }
84
85 int rnd_init(bool scan) { return 0; }
86 int rnd_next(unsigned char *buf) { return HA_ERR_END_OF_FILE; }
87 void position(const uchar *record) { }
88 int rnd_pos(uchar *buf, uchar *pos) { return HA_ERR_END_OF_FILE; }
89 int info(uint flag) { return 0; }
90 uint max_supported_keys() const { return 16; }
91 int create(const char *name, TABLE *table_arg,
92 HA_CREATE_INFO *create_info) { return HA_ERR_WRONG_COMMAND; }
93
94 int open(const char *name, int mode, uint test_if_locked);
95 int close(void);
96};
97
98TSD_share *ha_tsd::get_share()
99{
100 TSD_share *tmp_share;
101 lock_shared_ha_data();
102 if (!(tmp_share= static_cast<TSD_share*>(get_ha_share_ptr())))
103 {
104 tmp_share= new TSD_share;
105 if (!tmp_share)
106 goto err;
107
108 set_ha_share_ptr(static_cast<Handler_share*>(tmp_share));
109 }
110err:
111 unlock_shared_ha_data();
112 return tmp_share;
113}
114
115int ha_tsd::open(const char *name, int mode, uint test_if_locked)
116{
117 if (!(share= get_share()))
118 return HA_ERR_OUT_OF_MEM;
119
120 thr_lock_data_init(&share->lock,&lock,NULL);
121 return 0;
122}
123
124int ha_tsd::close(void)
125{
126 return 0;
127}
128
129static handler *create_handler(handlerton *hton, TABLE_SHARE *table,
130 MEM_ROOT *mem_root)
131{
132 return new (mem_root) ha_tsd(hton, table);
133}
134
135static int discover_table(handlerton *hton, THD* thd, TABLE_SHARE *share)
136{
137 const char *sql= THDVAR(thd, statement);
138
139 // the table is discovered if sql starts from "table_name:"
140 if (!sql ||
141 strncmp(sql, share->table_name.str, share->table_name.length) ||
142 sql[share->table_name.length] != ':')
143 return HA_ERR_NO_SUCH_TABLE;
144
145 sql+= share->table_name.length + 1;
146 return share->init_from_sql_statement_string(thd, THDVAR(thd, write_frm),
147 sql, strlen(sql));
148}
149
150static int init(void *p)
151{
152 handlerton *hton = (handlerton *)p;
153 hton->create = create_handler;
154 hton->discover_table = discover_table;
155 return 0;
156}
157
158struct st_mysql_storage_engine descriptor =
159{ MYSQL_HANDLERTON_INTERFACE_VERSION };
160
161maria_declare_plugin(test_sql_discovery)
162{
163 MYSQL_STORAGE_ENGINE_PLUGIN,
164 &descriptor,
165 "TEST_SQL_DISCOVERY",
166 "Sergei Golubchik",
167 "Minimal engine to test table discovery via sql statements",
168 PLUGIN_LICENSE_GPL,
169 init,
170 NULL,
171 0x0001,
172 NULL,
173 sysvars,
174 "0.1",
175 MariaDB_PLUGIN_MATURITY_EXPERIMENTAL
176}
177maria_declare_plugin_end;
178
179