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
188
189
190
191
192
193
194
195
196
197
198
199
200
201
202
203
204
205
206
207
208
209
210
211
212
213
214
215
216
217
218
219
220
221
222
223
224
225
226
227
228
229
230
231
232
233
234
235
236
237
238
239
240
241
242
243
244
245
246
247
248
249
250
251
252
253
254
255
256
257
258
259
260
261
262
263
264
265
266
267
268
269
270
271
272
273
274
275
276
277
278
279
280
281
282
283
284
285
286
287
288
289
290
291
292
293
294
295
296
297
298
299
300
301
302
303
304
305
306
307
308
309
310
311
312
313
314
315
316
317
318
319
320
321
322
323
324
325
326
327
328
329
330
331
332
333
334
335
336
337
338
339
340
341
342
343
344
345
346
347
348
349
350
351
352
353
354
355
356
357
358
359
360
361
362
363
364
365
366
367
368
369
370
371
372
373
374
375
376
377
378
379
380
381
382
|
/* Copyright (C) 2000-2003 MySQL 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 */
/* create and drop of databases */
#include <config.h>
#include <fcntl.h>
#include <sys/stat.h>
#include <sys/types.h>
#include <set>
#include <string>
#include <fstream>
#include <drizzled/error.h>
#include <drizzled/gettext.h>
#include <drizzled/internal/m_string.h>
#include <drizzled/session.h>
#include <drizzled/schema.h>
#include <drizzled/sql_base.h>
#include <drizzled/lock.h>
#include <drizzled/errmsg_print.h>
#include <drizzled/transaction_services.h>
#include <drizzled/message/schema.pb.h>
#include <drizzled/sql_table.h>
#include <drizzled/plugin/storage_engine.h>
#include <drizzled/plugin/authorization.h>
#include <drizzled/pthread_globals.h>
#include <drizzled/charset.h>
#include <drizzled/internal/my_sys.h>
#include <drizzled/catalog/instance.h>
#include <boost/thread/mutex.hpp>
using namespace std;
namespace drizzled {
namespace schema {
/*
Create a database
SYNOPSIS
create_db()
session Thread handler
db Name of database to create
Function assumes that this is already validated.
create_info Database create options (like character set)
SIDE-EFFECTS
1. Report back to client that command succeeded (my_ok)
2. Report errors to client
3. Log event to binary log
RETURN VALUES
false ok
true Error
*/
bool create(Session &session, const message::Schema &schema_message, const bool is_if_not_exists)
{
bool error= false;
/*
Do not create database if another thread is holding read lock.
Wait for global read lock before acquiring session->catalog()->schemaLock().
After wait_if_global_read_lock() we have protection against another
global read lock. If we would acquire session->catalog()->schemaLock() first,
another thread could step in and get the global read lock before we
reach wait_if_global_read_lock(). If this thread tries the same as we
(admin a db), it would then go and wait on session->catalog()->schemaLock()...
Furthermore wait_if_global_read_lock() checks if the current thread
has the global read lock and refuses the operation with
ER_CANT_UPDATE_WITH_READLOCK if applicable.
*/
if (session.wait_if_global_read_lock(false, true))
{
return false;
}
assert(schema_message.has_name());
assert(schema_message.has_collation());
// @todo push this lock down into the engine
{
boost::mutex::scoped_lock scopedLock(session.catalog().schemaLock());
// Check to see if it exists already.
identifier::Schema schema_identifier(session.catalog().identifier(),
schema_message.name());
if (plugin::StorageEngine::doesSchemaExist(schema_identifier))
{
if (not is_if_not_exists)
{
my_error(ER_DB_CREATE_EXISTS, schema_identifier);
error= true;
}
else
{
push_warning_printf(&session, DRIZZLE_ERROR::WARN_LEVEL_NOTE,
ER_DB_CREATE_EXISTS, ER(ER_DB_CREATE_EXISTS),
schema_message.name().c_str());
session.my_ok();
}
}
else if (not plugin::StorageEngine::createSchema(schema_message)) // Try to create it
{
my_error(ER_CANT_CREATE_DB, MYF(0), schema_message.name().c_str(), errno);
error= true;
}
else // Created !
{
TransactionServices::createSchema(session, schema_message);
session.my_ok(1);
}
}
session.startWaitingGlobalReadLock();
return error;
}
/* db-name is already validated when we come here */
bool alter(Session &session,
const message::Schema &schema_message,
const message::Schema &original_schema)
{
/*
Do not alter database if another thread is holding read lock.
Wait for global read lock before acquiring session->catalog()->schemaLock().
After wait_if_global_read_lock() we have protection against another
global read lock. If we would acquire session->catalog()->schemaLock() first,
another thread could step in and get the global read lock before we
reach wait_if_global_read_lock(). If this thread tries the same as we
(admin a db), it would then go and wait on session->catalog()->schemaLock()...
Furthermore wait_if_global_read_lock() checks if the current thread
has the global read lock and refuses the operation with
ER_CANT_UPDATE_WITH_READLOCK if applicable.
*/
if ((session.wait_if_global_read_lock(false, true)))
return false;
bool success;
{
boost::mutex::scoped_lock scopedLock(session.catalog().schemaLock());
identifier::Schema schema_idenifier(session.catalog().identifier(),
schema_message.name());
if (not plugin::StorageEngine::doesSchemaExist(schema_idenifier))
{
my_error(ER_SCHEMA_DOES_NOT_EXIST, schema_idenifier);
return false;
}
/* Change options if current database is being altered. */
success= plugin::StorageEngine::alterSchema(schema_message);
if (success)
{
TransactionServices::alterSchema(session, original_schema, schema_message);
session.my_ok(1);
}
else
{
my_error(ER_ALTER_SCHEMA, schema_idenifier);
}
}
session.startWaitingGlobalReadLock();
return success;
}
/*
Drop all tables in a database and the database itself
SYNOPSIS
rm_db()
session Thread handle
db Database name in the case given by user
It's already validated and set to lower case
(if needed) when we come here
if_exists Don't give error if database doesn't exists
silent Don't generate errors
RETURN
false ok (Database dropped)
ERROR Error
*/
bool drop(Session &session, const identifier::Schema &schema_identifier, bool if_exists)
{
/*
Do not drop database if another thread is holding read lock.
Wait for global read lock before acquiring session->catalog()->schemaLock().
After wait_if_global_read_lock() we have protection against another
global read lock. If we would acquire session->catalog()->schemaLock() first,
another thread could step in and get the global read lock before we
reach wait_if_global_read_lock(). If this thread tries the same as we
(admin a db), it would then go and wait on session->catalog()->schemaLock()...
Furthermore wait_if_global_read_lock() checks if the current thread
has the global read lock and refuses the operation with
ER_CANT_UPDATE_WITH_READLOCK if applicable.
*/
if (session.wait_if_global_read_lock(false, true))
{
return true;
}
bool error= false;
{
boost::mutex::scoped_lock scopedLock(session.catalog().schemaLock());
if (message::schema::shared_ptr message= plugin::StorageEngine::getSchemaDefinition(schema_identifier))
{
error= plugin::StorageEngine::dropSchema(session, schema_identifier, *message);
}
else if (if_exists)
{
push_warning_printf(&session, DRIZZLE_ERROR::WARN_LEVEL_NOTE, ER_DB_DROP_EXISTS, ER(ER_DB_DROP_EXISTS),
schema_identifier.getSQLPath().c_str());
}
else
{
error= true;
my_error(ER_DB_DROP_EXISTS, schema_identifier);
}
};
/*
If this database was the client's selected database, we silently
change the client's selected database to nothing (to have an empty
SELECT DATABASE() in the future). For this we free() session->db and set
it to 0.
*/
if (not error and schema_identifier.compare(*session.schema()))
session.set_schema("");
session.startWaitingGlobalReadLock();
return error;
}
/**
@brief Change the current database and its attributes unconditionally.
@param session thread handle
@param new_db_name database name
@param force_switch if force_switch is false, then the operation will fail if
- new_db_name is NULL or empty;
- OR new database name is invalid
(check_db_name() failed);
- OR user has no privilege on the new database;
- OR new database does not exist;
if force_switch is true, then
- if new_db_name is NULL or empty, the current
database will be NULL, @@collation_database will
be set to @@collation_server, the operation will
succeed.
- if new database name is invalid
(check_db_name() failed), the current database
will be NULL, @@collation_database will be set to
@@collation_server, but the operation will fail;
- user privileges will not be checked
(Session::db_access however is updated);
TODO: is this really the intention?
(see sp-security.test).
- if new database does not exist,the current database
will be NULL, @@collation_database will be set to
@@collation_server, a warning will be thrown, the
operation will succeed.
@details The function checks that the database name corresponds to a
valid and existent database, checks access rights and changes the current
database with database attributes (@@collation_database session variable,
Session::db_access).
This function is not the only way to switch the database that is
currently employed. When the replication slave thread switches the
database before executing a query, it calls session->set_db directly.
However, if the query, in turn, uses a stored routine, the stored routine
will use this function, even if it's run on the slave.
This function allocates the name of the database on the system heap: this
is necessary to be able to uniformly change the database from any module
of the server. Up to 5.0 different modules were using different memory to
store the name of the database, and this led to memory corruption:
a stack pointer set by Stored Procedures was used by replication after
the stack address was long gone.
@return Operation status
@retval false Success
@retval true Error
*/
bool change(Session &session, const identifier::Schema &schema_identifier)
{
if (not plugin::Authorization::isAuthorized(*session.user(), schema_identifier))
{
/* Error message is set in isAuthorized */
return true;
}
if (not check(session, schema_identifier))
{
my_error(ER_WRONG_DB_NAME, schema_identifier);
return true;
}
if (not plugin::StorageEngine::doesSchemaExist(schema_identifier))
{
my_error(ER_BAD_DB_ERROR, schema_identifier);
/* The operation failed. */
return true;
}
session.set_schema(schema_identifier.getSchemaName());
return false;
}
/**
@brief Internal implementation: switch current database to a valid one.
@param session Thread context.
@param new_db_name Name of the database to switch to. The function will
take ownership of the name (the caller must not free
the allocated memory). If the name is NULL, we're
going to switch to NULL db.
@param new_db_charset Character set of the new database.
*/
/*
Check if database name is valid
SYNPOSIS
check()
org_name Name of database and length
RETURN
false error
true ok
*/
bool check(Session &session, const identifier::Schema &schema_identifier)
{
if (not plugin::Authorization::isAuthorized(*session.user(), schema_identifier))
return false;
return schema_identifier.isValid();
}
} /* namespace schema */
} /* namespace drizzled */
|