summaryrefslogtreecommitdiff
path: root/sql/replication.h
blob: 4731c2246ef02fad544dc4dac36aac30cd31bccb (plain)
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
383
384
385
386
387
388
389
390
391
392
393
394
395
396
397
398
399
400
401
402
403
404
405
406
407
408
409
410
411
412
413
414
415
416
417
418
419
420
421
422
423
424
425
426
427
428
429
430
431
432
433
434
435
436
437
438
439
440
441
442
443
444
445
446
447
448
449
450
451
452
453
454
455
456
457
458
459
460
461
462
463
464
465
466
467
468
469
470
471
472
473
474
475
476
477
478
479
480
481
482
483
484
485
486
487
488
489
490
491
492
493
494
495
496
497
498
499
500
501
502
503
504
505
506
507
508
509
510
511
512
513
514
515
516
517
518
519
520
521
522
523
524
525
526
527
528
529
530
531
532
533
534
535
536
537
538
539
540
541
542
543
544
545
546
547
548
549
550
551
552
553
554
555
556
557
558
559
560
561
562
563
564
565
566
567
568
569
/* Copyright (c) 2008, 2010, Oracle and/or its affiliates. All rights reserved.

   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,
   51 Franklin Street, Suite 500, Boston, MA 02110-1335 USA */

#ifndef REPLICATION_H
#define REPLICATION_H

/***************************************************************************
  NOTE: plugin locking.
  This API was created specifically for the semisync plugin and its locking
  logic is also matches semisync plugin usage pattern.  In particular, a plugin
  is locked on Binlog_transmit_observer::transmit_start and is unlocked after
  Binlog_transmit_observer::transmit_stop.  All other master observable events
  happen between these two and don't lock the plugin at all. This works well
  for the semisync_master plugin.

  Also a plugin is locked on Binlog_relay_IO_observer::thread_start
  and unlocked after Binlog_relay_IO_observer::thread_stop. This works well for
  the semisync_slave plugin.
***************************************************************************/

#include <mysql.h>

typedef struct st_mysql MYSQL;

#ifdef __cplusplus
extern "C" {
#endif

/**
   Transaction observer flags.
*/
enum Trans_flags {
  /** Transaction is a real transaction */
  TRANS_IS_REAL_TRANS = 1
};

/**
   Transaction observer parameter
*/
typedef struct Trans_param {
  uint32 server_id;
  uint32 flags;

  /*
    The latest binary log file name and position written by current
    transaction, if binary log is disabled or no log event has been
    written into binary log file by current transaction (events
    written into transaction log cache are not counted), these two
    member will be zero.
  */
  const char *log_file;
  my_off_t log_pos;
} Trans_param;

/**
   Observes and extends transaction execution
*/
typedef struct Trans_observer {
  uint32 len;

  /**
     This callback is called after transaction commit
     
     This callback is called right after commit to storage engines for
     transactional tables.

     For non-transactional tables, this is called at the end of the
     statement, before sending statement status, if the statement
     succeeded.

     @note The return value is currently ignored by the server.
     @note This hook is called wo/ any global mutex held

     @param param The parameter for transaction observers

     @retval 0 Sucess
     @retval 1 Failure
  */
  int (*after_commit)(Trans_param *param);

  /**
     This callback is called after transaction rollback

     This callback is called right after rollback to storage engines
     for transactional tables.

     For non-transactional tables, this is called at the end of the
     statement, before sending statement status, if the statement
     failed.

     @note The return value is currently ignored by the server.

     @param param The parameter for transaction observers

     @note This hook is called wo/ any global mutex held

     @retval 0 Sucess
     @retval 1 Failure
  */
  int (*after_rollback)(Trans_param *param);
} Trans_observer;

/**
   Binlog storage flags
*/
enum Binlog_storage_flags {
  /** Binary log was sync:ed */
  BINLOG_STORAGE_IS_SYNCED = 1,

  /** First(or alone) in a group commit */
  BINLOG_GROUP_COMMIT_LEADER = 2,

  /** Last(or alone) in a group commit */
  BINLOG_GROUP_COMMIT_TRAILER = 4
};

/**
   Binlog storage observer parameters
 */
typedef struct Binlog_storage_param {
  uint32 server_id;
} Binlog_storage_param;

/**
   Observe binlog logging storage
*/
typedef struct Binlog_storage_observer {
  uint32 len;

  /**
     This callback is called after binlog has been flushed

     This callback is called after cached events have been flushed to
     binary log file. Whether the binary log file is synchronized to
     disk is indicated by the bit BINLOG_STORAGE_IS_SYNCED in @a flags.

     @note: this hook is called with LOCK_log mutex held

     @param param Observer common parameter
     @param log_file Binlog file name been updated
     @param log_pos Binlog position after update
     @param flags flags for binlog storage

     @retval 0 Sucess
     @retval 1 Failure
  */
  int (*after_flush)(Binlog_storage_param *param,
                     const char *log_file, my_off_t log_pos,
                     uint32 flags);

  /**
     This callback is called after binlog has been synced

     This callback is called after events flushed to disk has been sync:ed
     ("group committed").

     @note: this hook is called with LOCK_after_binlog_sync mutex held

     @param param Observer common parameter
     @param log_file Binlog file name been updated
     @param log_pos Binlog position after update
     @param flags flags for binlog storage

     @retval 0 Sucess
     @retval 1 Failure
  */
  int (*after_sync)(Binlog_storage_param *param,
                    const char *log_file, my_off_t log_pos,
                    uint32 flags);
} Binlog_storage_observer;

/**
   Replication binlog transmitter (binlog dump) observer parameter.
*/
typedef struct Binlog_transmit_param {
  uint32 server_id;
  uint32 flags;
} Binlog_transmit_param;

/**
   Observe and extends the binlog dumping thread.
*/
typedef struct Binlog_transmit_observer {
  uint32 len;
  
  /**
     This callback is called when binlog dumping starts


     @param param Observer common parameter
     @param log_file Binlog file name to transmit from
     @param log_pos Binlog position to transmit from

     @retval 0 Sucess
     @retval 1 Failure
  */
  int (*transmit_start)(Binlog_transmit_param *param,
                        const char *log_file, my_off_t log_pos);

  /**
     This callback is called when binlog dumping stops

     @param param Observer common parameter
     
     @retval 0 Sucess
     @retval 1 Failure
  */
  int (*transmit_stop)(Binlog_transmit_param *param);

  /**
     This callback is called to reserve bytes in packet header for event transmission

     This callback is called when resetting transmit packet header to
     reserve bytes for this observer in packet header.

     The @a header buffer is allocated by the server code, and @a size
     is the size of the header buffer. Each observer can only reserve
     a maximum size of @a size in the header.

     @param param Observer common parameter
     @param header Pointer of the header buffer
     @param size Size of the header buffer
     @param len Header length reserved by this observer

     @retval 0 Sucess
     @retval 1 Failure
  */
  int (*reserve_header)(Binlog_transmit_param *param,
                        unsigned char *header,
                        unsigned long size,
                        unsigned long *len);

  /**
     This callback is called before sending an event packet to slave

     @param param Observer common parameter
     @param packet Binlog event packet to send
     @param len Length of the event packet
     @param log_file Binlog file name of the event packet to send
     @param log_pos Binlog position of the event packet to send

     @retval 0 Sucess
     @retval 1 Failure
  */
  int (*before_send_event)(Binlog_transmit_param *param,
                           unsigned char *packet, unsigned long len,
                           const char *log_file, my_off_t log_pos );

  /**
     This callback is called after sending an event packet to slave

     @param param Observer common parameter
     @param event_buf Binlog event packet buffer sent
     @param len length of the event packet buffer

     @retval 0 Sucess
     @retval 1 Failure
   */
  int (*after_send_event)(Binlog_transmit_param *param,
                          const char *event_buf, unsigned long len);

  /**
     This callback is called after resetting master status

     This is called when executing the command RESET MASTER, and is
     used to reset status variables added by observers.

     @param param Observer common parameter

     @retval 0 Sucess
     @retval 1 Failure
  */
  int (*after_reset_master)(Binlog_transmit_param *param);
} Binlog_transmit_observer;

/**
   Binlog relay IO flags
*/
enum Binlog_relay_IO_flags {
  /** Binary relay log was sync:ed */
  BINLOG_RELAY_IS_SYNCED = 1
};


/**
  Replication binlog relay IO observer parameter
*/
typedef struct Binlog_relay_IO_param {
  uint32 server_id;

  /* Master host, user and port */
  char *host;
  char *user;
  unsigned int port;

  char *master_log_name;
  my_off_t master_log_pos;

  MYSQL *mysql;                        /* the connection to master */
} Binlog_relay_IO_param;

/**
   Observes and extends the service of slave IO thread.
*/
typedef struct Binlog_relay_IO_observer {
  uint32 len;

  /**
     This callback is called when slave IO thread starts

     @param param Observer common parameter

     @retval 0 Sucess
     @retval 1 Failure
  */
  int (*thread_start)(Binlog_relay_IO_param *param);

  /**
     This callback is called when slave IO thread stops

     @param param Observer common parameter

     @retval 0 Sucess
     @retval 1 Failure
  */
  int (*thread_stop)(Binlog_relay_IO_param *param);

  /**
     This callback is called before slave requesting binlog transmission from master

     This is called before slave issuing BINLOG_DUMP command to master
     to request binlog.

     @param param Observer common parameter
     @param flags binlog dump flags

     @retval 0 Sucess
     @retval 1 Failure
  */
  int (*before_request_transmit)(Binlog_relay_IO_param *param, uint32 flags);

  /**
     This callback is called after read an event packet from master

     @param param Observer common parameter
     @param packet The event packet read from master
     @param len Length of the event packet read from master
     @param event_buf The event packet return after process
     @param event_len The length of event packet return after process

     @retval 0 Sucess
     @retval 1 Failure
  */
  int (*after_read_event)(Binlog_relay_IO_param *param,
                          const char *packet, unsigned long len,
                          const char **event_buf, unsigned long *event_len);

  /**
     This callback is called after written an event packet to relay log

     @param param Observer common parameter
     @param event_buf Event packet written to relay log
     @param event_len Length of the event packet written to relay log
     @param flags flags for relay log

     @retval 0 Sucess
     @retval 1 Failure
  */
  int (*after_queue_event)(Binlog_relay_IO_param *param,
                           const char *event_buf, unsigned long event_len,
                           uint32 flags);

  /**
     This callback is called after reset slave relay log IO status
     
     @param param Observer common parameter

     @retval 0 Sucess
     @retval 1 Failure
  */
  int (*after_reset_slave)(Binlog_relay_IO_param *param);
} Binlog_relay_IO_observer;


/**
   Register a transaction observer

   @param observer The transaction observer to register
   @param p pointer to the internal plugin structure

   @retval 0 Sucess
   @retval 1 Observer already exists
*/
int register_trans_observer(Trans_observer *observer, void *p);

/**
   Unregister a transaction observer

   @param observer The transaction observer to unregister
   @param p pointer to the internal plugin structure

   @retval 0 Sucess
   @retval 1 Observer not exists
*/
int unregister_trans_observer(Trans_observer *observer, void *p);

/**
   Register a binlog storage observer

   @param observer The binlog storage observer to register
   @param p pointer to the internal plugin structure

   @retval 0 Sucess
   @retval 1 Observer already exists
*/
int register_binlog_storage_observer(Binlog_storage_observer *observer, void *p);

/**
   Unregister a binlog storage observer

   @param observer The binlog storage observer to unregister
   @param p pointer to the internal plugin structure

   @retval 0 Sucess
   @retval 1 Observer not exists
*/
int unregister_binlog_storage_observer(Binlog_storage_observer *observer, void *p);

/**
   Register a binlog transmit observer

   @param observer The binlog transmit observer to register
   @param p pointer to the internal plugin structure

   @retval 0 Sucess
   @retval 1 Observer already exists
*/
int register_binlog_transmit_observer(Binlog_transmit_observer *observer, void *p);

/**
   Unregister a binlog transmit observer

   @param observer The binlog transmit observer to unregister
   @param p pointer to the internal plugin structure

   @retval 0 Sucess
   @retval 1 Observer not exists
*/
int unregister_binlog_transmit_observer(Binlog_transmit_observer *observer, void *p);

/**
   Register a binlog relay IO (slave IO thread) observer

   @param observer The binlog relay IO observer to register
   @param p pointer to the internal plugin structure

   @retval 0 Sucess
   @retval 1 Observer already exists
*/
int register_binlog_relay_io_observer(Binlog_relay_IO_observer *observer, void *p);

/**
   Unregister a binlog relay IO (slave IO thread) observer

   @param observer The binlog relay IO observer to unregister
   @param p pointer to the internal plugin structure

   @retval 0 Sucess
   @retval 1 Observer not exists
*/
int unregister_binlog_relay_io_observer(Binlog_relay_IO_observer *observer, void *p);

/**
   Connect to master

   This function can only used in the slave I/O thread context, and
   will use the same master information to do the connection.

   @code
   MYSQL *mysql = mysql_init(NULL);
   if (rpl_connect_master(mysql))
   {
     // do stuff with the connection
   }
   mysql_close(mysql); // close the connection
   @endcode
   
   @param mysql address of MYSQL structure to use, pass NULL will
   create a new one

   @return address of MYSQL structure on success, NULL on failure
*/
MYSQL *rpl_connect_master(MYSQL *mysql);

/**
   Get the value of user variable as an integer.

   This function will return the value of variable @a name as an
   integer. If the original value of the variable is not an integer,
   the value will be converted into an integer.

   @param name     user variable name
   @param value    pointer to return the value
   @param null_value if not NULL, the function will set it to true if
   the value of variable is null, set to false if not

   @retval 0 Success
   @retval 1 Variable not found
*/
int get_user_var_int(const char *name,
                     long long int *value, int *null_value);

/**
   Get the value of user variable as a double precision float number.

   This function will return the value of variable @a name as real
   number. If the original value of the variable is not a real number,
   the value will be converted into a real number.

   @param name     user variable name
   @param value    pointer to return the value
   @param null_value if not NULL, the function will set it to true if
   the value of variable is null, set to false if not

   @retval 0 Success
   @retval 1 Variable not found
*/
int get_user_var_real(const char *name,
                      double *value, int *null_value);

/**
   Get the value of user variable as a string.

   This function will return the value of variable @a name as
   string. If the original value of the variable is not a string,
   the value will be converted into a string.

   @param name     user variable name
   @param value    pointer to the value buffer
   @param len      length of the value buffer
   @param precision precision of the value if it is a float number
   @param null_value if not NULL, the function will set it to true if
   the value of variable is null, set to false if not

   @retval 0 Success
   @retval 1 Variable not found
*/
int get_user_var_str(const char *name,
                     char *value, unsigned long len,
                     unsigned int precision, int *null_value);

  

#ifdef __cplusplus
}
#endif
#endif /* REPLICATION_H */