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[lhc/web/wiklou.git] / includes / libs / rdbms / database / Database.php
1 <?php
2 /**
3 * @defgroup Database Database
4 *
5 * This file deals with database interface functions
6 * and query specifics/optimisations.
7 *
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
12 *
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
17 *
18 * You should have received a copy of the GNU General Public License along
19 * with this program; if not, write to the Free Software Foundation, Inc.,
20 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
21 * http://www.gnu.org/copyleft/gpl.html
22 *
23 * @file
24 * @ingroup Database
25 */
26 namespace Wikimedia\Rdbms;
27
28 use Psr\Log\LoggerAwareInterface;
29 use Psr\Log\LoggerInterface;
30 use Psr\Log\NullLogger;
31 use Wikimedia\ScopedCallback;
32 use Wikimedia\Timestamp\ConvertibleTimestamp;
33 use Wikimedia;
34 use BagOStuff;
35 use HashBagOStuff;
36 use LogicException;
37 use InvalidArgumentException;
38 use UnexpectedValueException;
39 use Exception;
40 use RuntimeException;
41
42 /**
43 * Relational database abstraction object
44 *
45 * @ingroup Database
46 * @since 1.28
47 */
48 abstract class Database implements IDatabase, IMaintainableDatabase, LoggerAwareInterface {
49 /** Number of times to re-try an operation in case of deadlock */
50 const DEADLOCK_TRIES = 4;
51 /** Minimum time to wait before retry, in microseconds */
52 const DEADLOCK_DELAY_MIN = 500000;
53 /** Maximum time to wait before retry */
54 const DEADLOCK_DELAY_MAX = 1500000;
55
56 /** How long before it is worth doing a dummy query to test the connection */
57 const PING_TTL = 1.0;
58 const PING_QUERY = 'SELECT 1 AS ping';
59
60 const TINY_WRITE_SEC = 0.010;
61 const SLOW_WRITE_SEC = 0.500;
62 const SMALL_WRITE_ROWS = 100;
63
64 /** @var string Whether lock granularity is on the level of the entire database */
65 const ATTR_DB_LEVEL_LOCKING = 'db-level-locking';
66
67 /** @var int New Database instance will not be connected yet when returned */
68 const NEW_UNCONNECTED = 0;
69 /** @var int New Database instance will already be connected when returned */
70 const NEW_CONNECTED = 1;
71
72 /** @var string SQL query */
73 protected $lastQuery = '';
74 /** @var float|bool UNIX timestamp of last write query */
75 protected $lastWriteTime = false;
76 /** @var string|bool */
77 protected $phpError = false;
78 /** @var string Server that this instance is currently connected to */
79 protected $server;
80 /** @var string User that this instance is currently connected under the name of */
81 protected $user;
82 /** @var string Password used to establish the current connection */
83 protected $password;
84 /** @var string Database that this instance is currently connected to */
85 protected $dbName;
86 /** @var array[] Map of (table => (dbname, schema, prefix) map) */
87 protected $tableAliases = [];
88 /** @var string[] Map of (index alias => index) */
89 protected $indexAliases = [];
90 /** @var bool Whether this PHP instance is for a CLI script */
91 protected $cliMode;
92 /** @var string Agent name for query profiling */
93 protected $agent;
94 /** @var array Parameters used by initConnection() to establish a connection */
95 protected $connectionParams = [];
96 /** @var BagOStuff APC cache */
97 protected $srvCache;
98 /** @var LoggerInterface */
99 protected $connLogger;
100 /** @var LoggerInterface */
101 protected $queryLogger;
102 /** @var callback Error logging callback */
103 protected $errorLogger;
104 /** @var callback Deprecation logging callback */
105 protected $deprecationLogger;
106
107 /** @var resource|null Database connection */
108 protected $conn = null;
109 /** @var bool */
110 protected $opened = false;
111
112 /** @var array[] List of (callable, method name, atomic section id) */
113 protected $trxIdleCallbacks = [];
114 /** @var array[] List of (callable, method name, atomic section id) */
115 protected $trxPreCommitCallbacks = [];
116 /** @var array[] List of (callable, method name, atomic section id) */
117 protected $trxEndCallbacks = [];
118 /** @var callable[] Map of (name => callable) */
119 protected $trxRecurringCallbacks = [];
120 /** @var bool Whether to suppress triggering of transaction end callbacks */
121 protected $trxEndCallbacksSuppressed = false;
122
123 /** @var string */
124 protected $tablePrefix = '';
125 /** @var string */
126 protected $schema = '';
127 /** @var int */
128 protected $flags;
129 /** @var array */
130 protected $lbInfo = [];
131 /** @var array|bool */
132 protected $schemaVars = false;
133 /** @var array */
134 protected $sessionVars = [];
135 /** @var array|null */
136 protected $preparedArgs;
137 /** @var string|bool|null Stashed value of html_errors INI setting */
138 protected $htmlErrors;
139 /** @var string */
140 protected $delimiter = ';';
141 /** @var DatabaseDomain */
142 protected $currentDomain;
143 /** @var integer|null Rows affected by the last query to query() or its CRUD wrappers */
144 protected $affectedRowCount;
145
146 /**
147 * @var int Transaction status
148 */
149 protected $trxStatus = self::STATUS_TRX_NONE;
150 /**
151 * @var Exception|null The last error that caused the status to become STATUS_TRX_ERROR
152 */
153 protected $trxStatusCause;
154 /**
155 * @var array|null If wasKnownStatementRollbackError() prevented trxStatus from being set,
156 * the relevant details are stored here.
157 */
158 protected $trxStatusIgnoredCause;
159 /**
160 * Either 1 if a transaction is active or 0 otherwise.
161 * The other Trx fields may not be meaningfull if this is 0.
162 *
163 * @var int
164 */
165 protected $trxLevel = 0;
166 /**
167 * Either a short hexidecimal string if a transaction is active or ""
168 *
169 * @var string
170 * @see Database::trxLevel
171 */
172 protected $trxShortId = '';
173 /**
174 * The UNIX time that the transaction started. Callers can assume that if
175 * snapshot isolation is used, then the data is *at least* up to date to that
176 * point (possibly more up-to-date since the first SELECT defines the snapshot).
177 *
178 * @var float|null
179 * @see Database::trxLevel
180 */
181 private $trxTimestamp = null;
182 /** @var float Lag estimate at the time of BEGIN */
183 private $trxReplicaLag = null;
184 /**
185 * Remembers the function name given for starting the most recent transaction via begin().
186 * Used to provide additional context for error reporting.
187 *
188 * @var string
189 * @see Database::trxLevel
190 */
191 private $trxFname = null;
192 /**
193 * Record if possible write queries were done in the last transaction started
194 *
195 * @var bool
196 * @see Database::trxLevel
197 */
198 private $trxDoneWrites = false;
199 /**
200 * Record if the current transaction was started implicitly due to DBO_TRX being set.
201 *
202 * @var bool
203 * @see Database::trxLevel
204 */
205 private $trxAutomatic = false;
206 /**
207 * Counter for atomic savepoint identifiers. Reset when a new transaction begins.
208 *
209 * @var int
210 */
211 private $trxAtomicCounter = 0;
212 /**
213 * Array of levels of atomicity within transactions
214 *
215 * @var array List of (name, unique ID, savepoint ID)
216 */
217 private $trxAtomicLevels = [];
218 /**
219 * Record if the current transaction was started implicitly by Database::startAtomic
220 *
221 * @var bool
222 */
223 private $trxAutomaticAtomic = false;
224 /**
225 * Track the write query callers of the current transaction
226 *
227 * @var string[]
228 */
229 private $trxWriteCallers = [];
230 /**
231 * @var float Seconds spent in write queries for the current transaction
232 */
233 private $trxWriteDuration = 0.0;
234 /**
235 * @var int Number of write queries for the current transaction
236 */
237 private $trxWriteQueryCount = 0;
238 /**
239 * @var int Number of rows affected by write queries for the current transaction
240 */
241 private $trxWriteAffectedRows = 0;
242 /**
243 * @var float Like trxWriteQueryCount but excludes lock-bound, easy to replicate, queries
244 */
245 private $trxWriteAdjDuration = 0.0;
246 /**
247 * @var int Number of write queries counted in trxWriteAdjDuration
248 */
249 private $trxWriteAdjQueryCount = 0;
250 /**
251 * @var float RTT time estimate
252 */
253 private $rttEstimate = 0.0;
254
255 /** @var array Map of (name => 1) for locks obtained via lock() */
256 private $namedLocksHeld = [];
257 /** @var array Map of (table name => 1) for TEMPORARY tables */
258 protected $sessionTempTables = [];
259
260 /** @var IDatabase|null Lazy handle to the master DB this server replicates from */
261 private $lazyMasterHandle;
262
263 /** @var float UNIX timestamp */
264 protected $lastPing = 0.0;
265
266 /** @var int[] Prior flags member variable values */
267 private $priorFlags = [];
268
269 /** @var object|string Class name or object With profileIn/profileOut methods */
270 protected $profiler;
271 /** @var TransactionProfiler */
272 protected $trxProfiler;
273
274 /** @var int */
275 protected $nonNativeInsertSelectBatchSize = 10000;
276
277 /** @var string Idiom used when a cancelable atomic section started the transaction */
278 private static $NOT_APPLICABLE = 'n/a';
279 /** @var string Prefix to the atomic section counter used to make savepoint IDs */
280 private static $SAVEPOINT_PREFIX = 'wikimedia_rdbms_atomic';
281
282 /** @var int Transaction is in a error state requiring a full or savepoint rollback */
283 const STATUS_TRX_ERROR = 1;
284 /** @var int Transaction is active and in a normal state */
285 const STATUS_TRX_OK = 2;
286 /** @var int No transaction is active */
287 const STATUS_TRX_NONE = 3;
288
289 /**
290 * @note: exceptions for missing libraries/drivers should be thrown in initConnection()
291 * @param array $params Parameters passed from Database::factory()
292 */
293 protected function __construct( array $params ) {
294 foreach ( [ 'host', 'user', 'password', 'dbname' ] as $name ) {
295 $this->connectionParams[$name] = $params[$name];
296 }
297
298 $this->schema = $params['schema'];
299 $this->tablePrefix = $params['tablePrefix'];
300
301 $this->cliMode = $params['cliMode'];
302 // Agent name is added to SQL queries in a comment, so make sure it can't break out
303 $this->agent = str_replace( '/', '-', $params['agent'] );
304
305 $this->flags = $params['flags'];
306 if ( $this->flags & self::DBO_DEFAULT ) {
307 if ( $this->cliMode ) {
308 $this->flags &= ~self::DBO_TRX;
309 } else {
310 $this->flags |= self::DBO_TRX;
311 }
312 }
313 // Disregard deprecated DBO_IGNORE flag (T189999)
314 $this->flags &= ~self::DBO_IGNORE;
315
316 $this->sessionVars = $params['variables'];
317
318 $this->srvCache = isset( $params['srvCache'] )
319 ? $params['srvCache']
320 : new HashBagOStuff();
321
322 $this->profiler = $params['profiler'];
323 $this->trxProfiler = $params['trxProfiler'];
324 $this->connLogger = $params['connLogger'];
325 $this->queryLogger = $params['queryLogger'];
326 $this->errorLogger = $params['errorLogger'];
327 $this->deprecationLogger = $params['deprecationLogger'];
328
329 if ( isset( $params['nonNativeInsertSelectBatchSize'] ) ) {
330 $this->nonNativeInsertSelectBatchSize = $params['nonNativeInsertSelectBatchSize'];
331 }
332
333 // Set initial dummy domain until open() sets the final DB/prefix
334 $this->currentDomain = DatabaseDomain::newUnspecified();
335 }
336
337 /**
338 * Initialize the connection to the database over the wire (or to local files)
339 *
340 * @throws LogicException
341 * @throws InvalidArgumentException
342 * @throws DBConnectionError
343 * @since 1.31
344 */
345 final public function initConnection() {
346 if ( $this->isOpen() ) {
347 throw new LogicException( __METHOD__ . ': already connected.' );
348 }
349 // Establish the connection
350 $this->doInitConnection();
351 // Set the domain object after open() sets the relevant fields
352 if ( $this->dbName != '' ) {
353 // Domains with server scope but a table prefix are not used by IDatabase classes
354 $this->currentDomain = new DatabaseDomain( $this->dbName, null, $this->tablePrefix );
355 }
356 }
357
358 /**
359 * Actually connect to the database over the wire (or to local files)
360 *
361 * @throws InvalidArgumentException
362 * @throws DBConnectionError
363 * @since 1.31
364 */
365 protected function doInitConnection() {
366 if ( strlen( $this->connectionParams['user'] ) ) {
367 $this->open(
368 $this->connectionParams['host'],
369 $this->connectionParams['user'],
370 $this->connectionParams['password'],
371 $this->connectionParams['dbname']
372 );
373 } else {
374 throw new InvalidArgumentException( "No database user provided." );
375 }
376 }
377
378 /**
379 * Construct a Database subclass instance given a database type and parameters
380 *
381 * This also connects to the database immediately upon object construction
382 *
383 * @param string $dbType A possible DB type (sqlite, mysql, postgres,...)
384 * @param array $p Parameter map with keys:
385 * - host : The hostname of the DB server
386 * - user : The name of the database user the client operates under
387 * - password : The password for the database user
388 * - dbname : The name of the database to use where queries do not specify one.
389 * The database must exist or an error might be thrown. Setting this to the empty string
390 * will avoid any such errors and make the handle have no implicit database scope. This is
391 * useful for queries like SHOW STATUS, CREATE DATABASE, or DROP DATABASE. Note that a
392 * "database" in Postgres is rougly equivalent to an entire MySQL server. This the domain
393 * in which user names and such are defined, e.g. users are database-specific in Postgres.
394 * - schema : The database schema to use (if supported). A "schema" in Postgres is roughly
395 * equivalent to a "database" in MySQL. Note that MySQL and SQLite do not use schemas.
396 * - tablePrefix : Optional table prefix that is implicitly added on to all table names
397 * recognized in queries. This can be used in place of schemas for handle site farms.
398 * - flags : Optional bitfield of DBO_* constants that define connection, protocol,
399 * buffering, and transaction behavior. It is STRONGLY adviced to leave the DBO_DEFAULT
400 * flag in place UNLESS this this database simply acts as a key/value store.
401 * - driver: Optional name of a specific DB client driver. For MySQL, there is only the
402 * 'mysqli' driver; the old one 'mysql' has been removed.
403 * - variables: Optional map of session variables to set after connecting. This can be
404 * used to adjust lock timeouts or encoding modes and the like.
405 * - connLogger: Optional PSR-3 logger interface instance.
406 * - queryLogger: Optional PSR-3 logger interface instance.
407 * - profiler: Optional class name or object with profileIn()/profileOut() methods.
408 * These will be called in query(), using a simplified version of the SQL that also
409 * includes the agent as a SQL comment.
410 * - trxProfiler: Optional TransactionProfiler instance.
411 * - errorLogger: Optional callback that takes an Exception and logs it.
412 * - deprecationLogger: Optional callback that takes a string and logs it.
413 * - cliMode: Whether to consider the execution context that of a CLI script.
414 * - agent: Optional name used to identify the end-user in query profiling/logging.
415 * - srvCache: Optional BagOStuff instance to an APC-style cache.
416 * - nonNativeInsertSelectBatchSize: Optional batch size for non-native INSERT SELECT emulation.
417 * @param int $connect One of the class constants (NEW_CONNECTED, NEW_UNCONNECTED) [optional]
418 * @return Database|null If the database driver or extension cannot be found
419 * @throws InvalidArgumentException If the database driver or extension cannot be found
420 * @since 1.18
421 */
422 final public static function factory( $dbType, $p = [], $connect = self::NEW_CONNECTED ) {
423 $class = self::getClass( $dbType, isset( $p['driver'] ) ? $p['driver'] : null );
424
425 if ( class_exists( $class ) && is_subclass_of( $class, IDatabase::class ) ) {
426 // Resolve some defaults for b/c
427 $p['host'] = isset( $p['host'] ) ? $p['host'] : false;
428 $p['user'] = isset( $p['user'] ) ? $p['user'] : false;
429 $p['password'] = isset( $p['password'] ) ? $p['password'] : false;
430 $p['dbname'] = isset( $p['dbname'] ) ? $p['dbname'] : false;
431 $p['flags'] = isset( $p['flags'] ) ? $p['flags'] : 0;
432 $p['variables'] = isset( $p['variables'] ) ? $p['variables'] : [];
433 $p['tablePrefix'] = isset( $p['tablePrefix'] ) ? $p['tablePrefix'] : '';
434 $p['schema'] = isset( $p['schema'] ) ? $p['schema'] : '';
435 $p['cliMode'] = isset( $p['cliMode'] )
436 ? $p['cliMode']
437 : ( PHP_SAPI === 'cli' || PHP_SAPI === 'phpdbg' );
438 $p['agent'] = isset( $p['agent'] ) ? $p['agent'] : '';
439 if ( !isset( $p['connLogger'] ) ) {
440 $p['connLogger'] = new NullLogger();
441 }
442 if ( !isset( $p['queryLogger'] ) ) {
443 $p['queryLogger'] = new NullLogger();
444 }
445 $p['profiler'] = isset( $p['profiler'] ) ? $p['profiler'] : null;
446 if ( !isset( $p['trxProfiler'] ) ) {
447 $p['trxProfiler'] = new TransactionProfiler();
448 }
449 if ( !isset( $p['errorLogger'] ) ) {
450 $p['errorLogger'] = function ( Exception $e ) {
451 trigger_error( get_class( $e ) . ': ' . $e->getMessage(), E_USER_WARNING );
452 };
453 }
454 if ( !isset( $p['deprecationLogger'] ) ) {
455 $p['deprecationLogger'] = function ( $msg ) {
456 trigger_error( $msg, E_USER_DEPRECATED );
457 };
458 }
459
460 /** @var Database $conn */
461 $conn = new $class( $p );
462 if ( $connect == self::NEW_CONNECTED ) {
463 $conn->initConnection();
464 }
465 } else {
466 $conn = null;
467 }
468
469 return $conn;
470 }
471
472 /**
473 * @param string $dbType A possible DB type (sqlite, mysql, postgres,...)
474 * @param string|null $driver Optional name of a specific DB client driver
475 * @return array Map of (Database::ATTRIBUTE_* constant => value) for all such constants
476 * @throws InvalidArgumentException
477 * @since 1.31
478 */
479 final public static function attributesFromType( $dbType, $driver = null ) {
480 static $defaults = [ self::ATTR_DB_LEVEL_LOCKING => false ];
481
482 $class = self::getClass( $dbType, $driver );
483
484 return call_user_func( [ $class, 'getAttributes' ] ) + $defaults;
485 }
486
487 /**
488 * @param string $dbType A possible DB type (sqlite, mysql, postgres,...)
489 * @param string|null $driver Optional name of a specific DB client driver
490 * @return string Database subclass name to use
491 * @throws InvalidArgumentException
492 */
493 private static function getClass( $dbType, $driver = null ) {
494 // For database types with built-in support, the below maps type to IDatabase
495 // implementations. For types with multipe driver implementations (PHP extensions),
496 // an array can be used, keyed by extension name. In case of an array, the
497 // optional 'driver' parameter can be used to force a specific driver. Otherwise,
498 // we auto-detect the first available driver. For types without built-in support,
499 // an class named "Database<Type>" us used, eg. DatabaseFoo for type 'foo'.
500 static $builtinTypes = [
501 'mssql' => DatabaseMssql::class,
502 'mysql' => [ 'mysqli' => DatabaseMysqli::class ],
503 'sqlite' => DatabaseSqlite::class,
504 'postgres' => DatabasePostgres::class,
505 ];
506
507 $dbType = strtolower( $dbType );
508 $class = false;
509
510 if ( isset( $builtinTypes[$dbType] ) ) {
511 $possibleDrivers = $builtinTypes[$dbType];
512 if ( is_string( $possibleDrivers ) ) {
513 $class = $possibleDrivers;
514 } else {
515 if ( (string)$driver !== '' ) {
516 if ( !isset( $possibleDrivers[$driver] ) ) {
517 throw new InvalidArgumentException( __METHOD__ .
518 " type '$dbType' does not support driver '{$driver}'" );
519 } else {
520 $class = $possibleDrivers[$driver];
521 }
522 } else {
523 foreach ( $possibleDrivers as $posDriver => $possibleClass ) {
524 if ( extension_loaded( $posDriver ) ) {
525 $class = $possibleClass;
526 break;
527 }
528 }
529 }
530 }
531 } else {
532 $class = 'Database' . ucfirst( $dbType );
533 }
534
535 if ( $class === false ) {
536 throw new InvalidArgumentException( __METHOD__ .
537 " no viable database extension found for type '$dbType'" );
538 }
539
540 return $class;
541 }
542
543 /**
544 * @return array Map of (Database::ATTRIBUTE_* constant => value
545 * @since 1.31
546 */
547 protected static function getAttributes() {
548 return [];
549 }
550
551 /**
552 * Set the PSR-3 logger interface to use for query logging. (The logger
553 * interfaces for connection logging and error logging can be set with the
554 * constructor.)
555 *
556 * @param LoggerInterface $logger
557 */
558 public function setLogger( LoggerInterface $logger ) {
559 $this->queryLogger = $logger;
560 }
561
562 public function getServerInfo() {
563 return $this->getServerVersion();
564 }
565
566 public function bufferResults( $buffer = null ) {
567 $res = !$this->getFlag( self::DBO_NOBUFFER );
568 if ( $buffer !== null ) {
569 $buffer
570 ? $this->clearFlag( self::DBO_NOBUFFER )
571 : $this->setFlag( self::DBO_NOBUFFER );
572 }
573
574 return $res;
575 }
576
577 public function trxLevel() {
578 return $this->trxLevel;
579 }
580
581 public function trxTimestamp() {
582 return $this->trxLevel ? $this->trxTimestamp : null;
583 }
584
585 /**
586 * @return int One of the STATUS_TRX_* class constants
587 * @since 1.31
588 */
589 public function trxStatus() {
590 return $this->trxStatus;
591 }
592
593 public function tablePrefix( $prefix = null ) {
594 $old = $this->tablePrefix;
595 if ( $prefix !== null ) {
596 $this->tablePrefix = $prefix;
597 $this->currentDomain = ( $this->dbName != '' )
598 ? new DatabaseDomain( $this->dbName, null, $this->tablePrefix )
599 : DatabaseDomain::newUnspecified();
600 }
601
602 return $old;
603 }
604
605 public function dbSchema( $schema = null ) {
606 $old = $this->schema;
607 if ( $schema !== null ) {
608 $this->schema = $schema;
609 }
610
611 return $old;
612 }
613
614 public function getLBInfo( $name = null ) {
615 if ( is_null( $name ) ) {
616 return $this->lbInfo;
617 } else {
618 if ( array_key_exists( $name, $this->lbInfo ) ) {
619 return $this->lbInfo[$name];
620 } else {
621 return null;
622 }
623 }
624 }
625
626 public function setLBInfo( $name, $value = null ) {
627 if ( is_null( $value ) ) {
628 $this->lbInfo = $name;
629 } else {
630 $this->lbInfo[$name] = $value;
631 }
632 }
633
634 public function setLazyMasterHandle( IDatabase $conn ) {
635 $this->lazyMasterHandle = $conn;
636 }
637
638 /**
639 * @return IDatabase|null
640 * @see setLazyMasterHandle()
641 * @since 1.27
642 */
643 protected function getLazyMasterHandle() {
644 return $this->lazyMasterHandle;
645 }
646
647 public function implicitGroupby() {
648 return true;
649 }
650
651 public function implicitOrderby() {
652 return true;
653 }
654
655 public function lastQuery() {
656 return $this->lastQuery;
657 }
658
659 public function doneWrites() {
660 return (bool)$this->lastWriteTime;
661 }
662
663 public function lastDoneWrites() {
664 return $this->lastWriteTime ?: false;
665 }
666
667 public function writesPending() {
668 return $this->trxLevel && $this->trxDoneWrites;
669 }
670
671 public function writesOrCallbacksPending() {
672 return $this->trxLevel && (
673 $this->trxDoneWrites ||
674 $this->trxIdleCallbacks ||
675 $this->trxPreCommitCallbacks ||
676 $this->trxEndCallbacks
677 );
678 }
679
680 /**
681 * @return string|null
682 */
683 final protected function getTransactionRoundId() {
684 // If transaction round participation is enabled, see if one is active
685 if ( $this->getFlag( self::DBO_TRX ) ) {
686 $id = $this->getLBInfo( 'trxRoundId' );
687
688 return is_string( $id ) ? $id : null;
689 }
690
691 return null;
692 }
693
694 public function pendingWriteQueryDuration( $type = self::ESTIMATE_TOTAL ) {
695 if ( !$this->trxLevel ) {
696 return false;
697 } elseif ( !$this->trxDoneWrites ) {
698 return 0.0;
699 }
700
701 switch ( $type ) {
702 case self::ESTIMATE_DB_APPLY:
703 $this->ping( $rtt );
704 $rttAdjTotal = $this->trxWriteAdjQueryCount * $rtt;
705 $applyTime = max( $this->trxWriteAdjDuration - $rttAdjTotal, 0 );
706 // For omitted queries, make them count as something at least
707 $omitted = $this->trxWriteQueryCount - $this->trxWriteAdjQueryCount;
708 $applyTime += self::TINY_WRITE_SEC * $omitted;
709
710 return $applyTime;
711 default: // everything
712 return $this->trxWriteDuration;
713 }
714 }
715
716 public function pendingWriteCallers() {
717 return $this->trxLevel ? $this->trxWriteCallers : [];
718 }
719
720 public function pendingWriteRowsAffected() {
721 return $this->trxWriteAffectedRows;
722 }
723
724 /**
725 * Get the list of method names that have pending write queries or callbacks
726 * for this transaction
727 *
728 * @return array
729 */
730 protected function pendingWriteAndCallbackCallers() {
731 if ( !$this->trxLevel ) {
732 return [];
733 }
734
735 $fnames = $this->trxWriteCallers;
736 foreach ( [
737 $this->trxIdleCallbacks,
738 $this->trxPreCommitCallbacks,
739 $this->trxEndCallbacks
740 ] as $callbacks ) {
741 foreach ( $callbacks as $callback ) {
742 $fnames[] = $callback[1];
743 }
744 }
745
746 return $fnames;
747 }
748
749 /**
750 * @return string
751 */
752 private function flatAtomicSectionList() {
753 return array_reduce( $this->trxAtomicLevels, function ( $accum, $v ) {
754 return $accum === null ? $v[0] : "$accum, " . $v[0];
755 } );
756 }
757
758 public function isOpen() {
759 return $this->opened;
760 }
761
762 public function setFlag( $flag, $remember = self::REMEMBER_NOTHING ) {
763 if ( ( $flag & self::DBO_IGNORE ) ) {
764 throw new UnexpectedValueException( "Modifying DBO_IGNORE is not allowed." );
765 }
766
767 if ( $remember === self::REMEMBER_PRIOR ) {
768 array_push( $this->priorFlags, $this->flags );
769 }
770 $this->flags |= $flag;
771 }
772
773 public function clearFlag( $flag, $remember = self::REMEMBER_NOTHING ) {
774 if ( ( $flag & self::DBO_IGNORE ) ) {
775 throw new UnexpectedValueException( "Modifying DBO_IGNORE is not allowed." );
776 }
777
778 if ( $remember === self::REMEMBER_PRIOR ) {
779 array_push( $this->priorFlags, $this->flags );
780 }
781 $this->flags &= ~$flag;
782 }
783
784 public function restoreFlags( $state = self::RESTORE_PRIOR ) {
785 if ( !$this->priorFlags ) {
786 return;
787 }
788
789 if ( $state === self::RESTORE_INITIAL ) {
790 $this->flags = reset( $this->priorFlags );
791 $this->priorFlags = [];
792 } else {
793 $this->flags = array_pop( $this->priorFlags );
794 }
795 }
796
797 public function getFlag( $flag ) {
798 return !!( $this->flags & $flag );
799 }
800
801 /**
802 * @param string $name Class field name
803 * @return mixed
804 * @deprecated Since 1.28
805 */
806 public function getProperty( $name ) {
807 return $this->$name;
808 }
809
810 public function getDomainID() {
811 return $this->currentDomain->getId();
812 }
813
814 final public function getWikiID() {
815 return $this->getDomainID();
816 }
817
818 /**
819 * Get information about an index into an object
820 * @param string $table Table name
821 * @param string $index Index name
822 * @param string $fname Calling function name
823 * @return mixed Database-specific index description class or false if the index does not exist
824 */
825 abstract function indexInfo( $table, $index, $fname = __METHOD__ );
826
827 /**
828 * Wrapper for addslashes()
829 *
830 * @param string $s String to be slashed.
831 * @return string Slashed string.
832 */
833 abstract function strencode( $s );
834
835 /**
836 * Set a custom error handler for logging errors during database connection
837 */
838 protected function installErrorHandler() {
839 $this->phpError = false;
840 $this->htmlErrors = ini_set( 'html_errors', '0' );
841 set_error_handler( [ $this, 'connectionErrorLogger' ] );
842 }
843
844 /**
845 * Restore the previous error handler and return the last PHP error for this DB
846 *
847 * @return bool|string
848 */
849 protected function restoreErrorHandler() {
850 restore_error_handler();
851 if ( $this->htmlErrors !== false ) {
852 ini_set( 'html_errors', $this->htmlErrors );
853 }
854
855 return $this->getLastPHPError();
856 }
857
858 /**
859 * @return string|bool Last PHP error for this DB (typically connection errors)
860 */
861 protected function getLastPHPError() {
862 if ( $this->phpError ) {
863 $error = preg_replace( '!\[<a.*</a>\]!', '', $this->phpError );
864 $error = preg_replace( '!^.*?:\s?(.*)$!', '$1', $error );
865
866 return $error;
867 }
868
869 return false;
870 }
871
872 /**
873 * Error handler for logging errors during database connection
874 * This method should not be used outside of Database classes
875 *
876 * @param int $errno
877 * @param string $errstr
878 */
879 public function connectionErrorLogger( $errno, $errstr ) {
880 $this->phpError = $errstr;
881 }
882
883 /**
884 * Create a log context to pass to PSR-3 logger functions.
885 *
886 * @param array $extras Additional data to add to context
887 * @return array
888 */
889 protected function getLogContext( array $extras = [] ) {
890 return array_merge(
891 [
892 'db_server' => $this->server,
893 'db_name' => $this->dbName,
894 'db_user' => $this->user,
895 ],
896 $extras
897 );
898 }
899
900 final public function close() {
901 $exception = null; // error to throw after disconnecting
902
903 if ( $this->conn ) {
904 // Resolve any dangling transaction first
905 if ( $this->trxLevel ) {
906 if ( $this->trxAtomicLevels ) {
907 // Cannot let incomplete atomic sections be committed
908 $levels = $this->flatAtomicSectionList();
909 $exception = new DBUnexpectedError(
910 $this,
911 __METHOD__ . ": atomic sections $levels are still open."
912 );
913 } elseif ( $this->trxAutomatic ) {
914 // Only the connection manager can commit non-empty DBO_TRX transactions
915 if ( $this->writesOrCallbacksPending() ) {
916 $exception = new DBUnexpectedError(
917 $this,
918 __METHOD__ .
919 ": mass commit/rollback of peer transaction required (DBO_TRX set)."
920 );
921 }
922 } elseif ( $this->trxLevel ) {
923 // Commit explicit transactions as if this was commit()
924 $this->queryLogger->warning(
925 __METHOD__ . ": writes or callbacks still pending.",
926 [ 'trace' => ( new RuntimeException() )->getTraceAsString() ]
927 );
928 }
929
930 if ( $this->trxEndCallbacksSuppressed ) {
931 $exception = $exception ?: new DBUnexpectedError(
932 $this,
933 __METHOD__ . ': callbacks are suppressed; cannot properly commit.'
934 );
935 }
936
937 // Commit or rollback the changes and run any callbacks as needed
938 if ( $this->trxStatus === self::STATUS_TRX_OK && !$exception ) {
939 $this->commit(
940 __METHOD__,
941 $this->trxAutomatic ? self::FLUSHING_INTERNAL : self::FLUSHING_ONE
942 );
943 } else {
944 $this->rollback( __METHOD__, self::FLUSHING_INTERNAL );
945 }
946 }
947
948 // Close the actual connection in the binding handle
949 $closed = $this->closeConnection();
950 $this->conn = false;
951 } else {
952 $closed = true; // already closed; nothing to do
953 }
954
955 $this->opened = false;
956
957 // Throw any unexpected errors after having disconnected
958 if ( $exception instanceof Exception ) {
959 throw $exception;
960 }
961
962 // Sanity check that no callbacks are dangling
963 if (
964 $this->trxIdleCallbacks || $this->trxPreCommitCallbacks || $this->trxEndCallbacks
965 ) {
966 throw new RuntimeException(
967 "Transaction callbacks are still pending:\n" .
968 implode( ', ', $this->pendingWriteAndCallbackCallers() )
969 );
970 }
971
972 return $closed;
973 }
974
975 /**
976 * Make sure isOpen() returns true as a sanity check
977 *
978 * @throws DBUnexpectedError
979 */
980 protected function assertOpen() {
981 if ( !$this->isOpen() ) {
982 throw new DBUnexpectedError( $this, "DB connection was already closed." );
983 }
984 }
985
986 /**
987 * Closes underlying database connection
988 * @since 1.20
989 * @return bool Whether connection was closed successfully
990 */
991 abstract protected function closeConnection();
992
993 /**
994 * @param string $error Fallback error message, used if none is given by DB
995 * @throws DBConnectionError
996 */
997 public function reportConnectionError( $error = 'Unknown error' ) {
998 $myError = $this->lastError();
999 if ( $myError ) {
1000 $error = $myError;
1001 }
1002
1003 # New method
1004 throw new DBConnectionError( $this, $error );
1005 }
1006
1007 /**
1008 * Run a query and return a DBMS-dependent wrapper (that has all IResultWrapper methods)
1009 *
1010 * This might return things, such as mysqli_result, that do not formally implement
1011 * IResultWrapper, but nonetheless implement all of its methods correctly
1012 *
1013 * @param string $sql SQL query.
1014 * @return IResultWrapper|bool Iterator to feed to fetchObject/fetchRow; false on failure
1015 */
1016 abstract protected function doQuery( $sql );
1017
1018 /**
1019 * Determine whether a query writes to the DB.
1020 * Should return true if unsure.
1021 *
1022 * @param string $sql
1023 * @return bool
1024 */
1025 protected function isWriteQuery( $sql ) {
1026 return !preg_match(
1027 '/^(?:SELECT|BEGIN|ROLLBACK|COMMIT|SET|SHOW|EXPLAIN|\(SELECT)\b/i', $sql );
1028 }
1029
1030 /**
1031 * @param string $sql
1032 * @return string|null
1033 */
1034 protected function getQueryVerb( $sql ) {
1035 return preg_match( '/^\s*([a-z]+)/i', $sql, $m ) ? strtoupper( $m[1] ) : null;
1036 }
1037
1038 /**
1039 * Determine whether a SQL statement is sensitive to isolation level.
1040 * A SQL statement is considered transactable if its result could vary
1041 * depending on the transaction isolation level. Operational commands
1042 * such as 'SET' and 'SHOW' are not considered to be transactable.
1043 *
1044 * @param string $sql
1045 * @return bool
1046 */
1047 protected function isTransactableQuery( $sql ) {
1048 return !in_array(
1049 $this->getQueryVerb( $sql ),
1050 [ 'BEGIN', 'COMMIT', 'ROLLBACK', 'SHOW', 'SET', 'CREATE', 'ALTER' ],
1051 true
1052 );
1053 }
1054
1055 /**
1056 * @param string $sql A SQL query
1057 * @return bool Whether $sql is SQL for TEMPORARY table operation
1058 */
1059 protected function registerTempTableOperation( $sql ) {
1060 if ( preg_match(
1061 '/^CREATE\s+TEMPORARY\s+TABLE\s+(?:IF\s+NOT\s+EXISTS\s+)?[`"\']?(\w+)[`"\']?/i',
1062 $sql,
1063 $matches
1064 ) ) {
1065 $this->sessionTempTables[$matches[1]] = 1;
1066
1067 return true;
1068 } elseif ( preg_match(
1069 '/^DROP\s+(?:TEMPORARY\s+)?TABLE\s+(?:IF\s+EXISTS\s+)?[`"\']?(\w+)[`"\']?/i',
1070 $sql,
1071 $matches
1072 ) ) {
1073 $isTemp = isset( $this->sessionTempTables[$matches[1]] );
1074 unset( $this->sessionTempTables[$matches[1]] );
1075
1076 return $isTemp;
1077 } elseif ( preg_match(
1078 '/^TRUNCATE\s+(?:TEMPORARY\s+)?TABLE\s+(?:IF\s+EXISTS\s+)?[`"\']?(\w+)[`"\']?/i',
1079 $sql,
1080 $matches
1081 ) ) {
1082 return isset( $this->sessionTempTables[$matches[1]] );
1083 } elseif ( preg_match(
1084 '/^(?:INSERT\s+(?:\w+\s+)?INTO|UPDATE|DELETE\s+FROM)\s+[`"\']?(\w+)[`"\']?/i',
1085 $sql,
1086 $matches
1087 ) ) {
1088 return isset( $this->sessionTempTables[$matches[1]] );
1089 }
1090
1091 return false;
1092 }
1093
1094 public function query( $sql, $fname = __METHOD__, $tempIgnore = false ) {
1095 $this->assertTransactionStatus( $sql, $fname );
1096
1097 # Avoid fatals if close() was called
1098 $this->assertOpen();
1099
1100 $priorWritesPending = $this->writesOrCallbacksPending();
1101 $this->lastQuery = $sql;
1102
1103 $isWrite = $this->isWriteQuery( $sql );
1104 if ( $isWrite ) {
1105 $isNonTempWrite = !$this->registerTempTableOperation( $sql );
1106 } else {
1107 $isNonTempWrite = false;
1108 }
1109
1110 if ( $isWrite ) {
1111 if ( $this->getLBInfo( 'replica' ) === true ) {
1112 throw new DBError(
1113 $this,
1114 'Write operations are not allowed on replica database connections.'
1115 );
1116 }
1117 # In theory, non-persistent writes are allowed in read-only mode, but due to things
1118 # like https://bugs.mysql.com/bug.php?id=33669 that might not work anyway...
1119 $reason = $this->getReadOnlyReason();
1120 if ( $reason !== false ) {
1121 throw new DBReadOnlyError( $this, "Database is read-only: $reason" );
1122 }
1123 # Set a flag indicating that writes have been done
1124 $this->lastWriteTime = microtime( true );
1125 }
1126
1127 # Add trace comment to the begin of the sql string, right after the operator.
1128 # Or, for one-word queries (like "BEGIN" or COMMIT") add it to the end (T44598)
1129 $commentedSql = preg_replace( '/\s|$/', " /* $fname {$this->agent} */ ", $sql, 1 );
1130
1131 # Start implicit transactions that wrap the request if DBO_TRX is enabled
1132 if ( !$this->trxLevel && $this->getFlag( self::DBO_TRX )
1133 && $this->isTransactableQuery( $sql )
1134 ) {
1135 $this->begin( __METHOD__ . " ($fname)", self::TRANSACTION_INTERNAL );
1136 $this->trxAutomatic = true;
1137 }
1138
1139 # Keep track of whether the transaction has write queries pending
1140 if ( $this->trxLevel && !$this->trxDoneWrites && $isWrite ) {
1141 $this->trxDoneWrites = true;
1142 $this->trxProfiler->transactionWritingIn(
1143 $this->server, $this->dbName, $this->trxShortId );
1144 }
1145
1146 if ( $this->getFlag( self::DBO_DEBUG ) ) {
1147 $this->queryLogger->debug( "{$this->dbName} {$commentedSql}" );
1148 }
1149
1150 # Send the query to the server and fetch any corresponding errors
1151 $ret = $this->doProfiledQuery( $sql, $commentedSql, $isNonTempWrite, $fname );
1152 $lastError = $this->lastError();
1153 $lastErrno = $this->lastErrno();
1154
1155 # Try reconnecting if the connection was lost
1156 if ( $ret === false && $this->wasConnectionLoss() ) {
1157 # Check if any meaningful session state was lost
1158 $recoverable = $this->canRecoverFromDisconnect( $sql, $priorWritesPending );
1159 # Update session state tracking and try to restore the connection
1160 $reconnected = $this->replaceLostConnection( __METHOD__ );
1161 # Silently resend the query to the server if it is safe and possible
1162 if ( $reconnected && $recoverable ) {
1163 $ret = $this->doProfiledQuery( $sql, $commentedSql, $isNonTempWrite, $fname );
1164 $lastError = $this->lastError();
1165 $lastErrno = $this->lastErrno();
1166
1167 if ( $ret === false && $this->wasConnectionLoss() ) {
1168 # Query probably causes disconnects; reconnect and do not re-run it
1169 $this->replaceLostConnection( __METHOD__ );
1170 }
1171 }
1172 }
1173
1174 if ( $ret === false ) {
1175 if ( $this->trxLevel ) {
1176 if ( !$this->wasKnownStatementRollbackError() ) {
1177 # Either the query was aborted or all queries after BEGIN where aborted.
1178 if ( $this->explicitTrxActive() || $priorWritesPending ) {
1179 # In the first case, the only options going forward are (a) ROLLBACK, or
1180 # (b) ROLLBACK TO SAVEPOINT (if one was set). If the later case, the only
1181 # option is ROLLBACK, since the snapshots would have been released.
1182 $this->trxStatus = self::STATUS_TRX_ERROR;
1183 $this->trxStatusCause =
1184 $this->makeQueryException( $lastError, $lastErrno, $sql, $fname );
1185 $tempIgnore = false; // cannot recover
1186 } else {
1187 # Nothing prior was there to lose from the transaction,
1188 # so just roll it back.
1189 $this->rollback( __METHOD__ . " ($fname)", self::FLUSHING_INTERNAL );
1190 }
1191 $this->trxStatusIgnoredCause = null;
1192 } else {
1193 # We're ignoring an error that caused just the current query to be aborted.
1194 # But log the cause so we can log a deprecation notice if a
1195 # caller actually does ignore it.
1196 $this->trxStatusIgnoredCause = [ $lastError, $lastErrno, $fname ];
1197 }
1198 }
1199
1200 $this->reportQueryError( $lastError, $lastErrno, $sql, $fname, $tempIgnore );
1201 }
1202
1203 return $this->resultObject( $ret );
1204 }
1205
1206 /**
1207 * Wrapper for query() that also handles profiling, logging, and affected row count updates
1208 *
1209 * @param string $sql Original SQL query
1210 * @param string $commentedSql SQL query with debugging/trace comment
1211 * @param bool $isWrite Whether the query is a (non-temporary) write operation
1212 * @param string $fname Name of the calling function
1213 * @return bool|ResultWrapper True for a successful write query, ResultWrapper
1214 * object for a successful read query, or false on failure
1215 */
1216 private function doProfiledQuery( $sql, $commentedSql, $isWrite, $fname ) {
1217 $isMaster = !is_null( $this->getLBInfo( 'master' ) );
1218 # generalizeSQL() will probably cut down the query to reasonable
1219 # logging size most of the time. The substr is really just a sanity check.
1220 if ( $isMaster ) {
1221 $queryProf = 'query-m: ' . substr( self::generalizeSQL( $sql ), 0, 255 );
1222 } else {
1223 $queryProf = 'query: ' . substr( self::generalizeSQL( $sql ), 0, 255 );
1224 }
1225
1226 # Include query transaction state
1227 $queryProf .= $this->trxShortId ? " [TRX#{$this->trxShortId}]" : "";
1228
1229 $startTime = microtime( true );
1230 if ( $this->profiler ) {
1231 call_user_func( [ $this->profiler, 'profileIn' ], $queryProf );
1232 }
1233 $this->affectedRowCount = null;
1234 $ret = $this->doQuery( $commentedSql );
1235 $this->affectedRowCount = $this->affectedRows();
1236 if ( $this->profiler ) {
1237 call_user_func( [ $this->profiler, 'profileOut' ], $queryProf );
1238 }
1239 $queryRuntime = max( microtime( true ) - $startTime, 0.0 );
1240
1241 unset( $queryProfSection ); // profile out (if set)
1242
1243 if ( $ret !== false ) {
1244 $this->lastPing = $startTime;
1245 if ( $isWrite && $this->trxLevel ) {
1246 $this->updateTrxWriteQueryTime( $sql, $queryRuntime, $this->affectedRows() );
1247 $this->trxWriteCallers[] = $fname;
1248 }
1249 }
1250
1251 if ( $sql === self::PING_QUERY ) {
1252 $this->rttEstimate = $queryRuntime;
1253 }
1254
1255 $this->trxProfiler->recordQueryCompletion(
1256 $queryProf, $startTime, $isWrite, $this->affectedRows()
1257 );
1258 $this->queryLogger->debug( $sql, [
1259 'method' => $fname,
1260 'master' => $isMaster,
1261 'runtime' => $queryRuntime,
1262 ] );
1263
1264 return $ret;
1265 }
1266
1267 /**
1268 * Update the estimated run-time of a query, not counting large row lock times
1269 *
1270 * LoadBalancer can be set to rollback transactions that will create huge replication
1271 * lag. It bases this estimate off of pendingWriteQueryDuration(). Certain simple
1272 * queries, like inserting a row can take a long time due to row locking. This method
1273 * uses some simple heuristics to discount those cases.
1274 *
1275 * @param string $sql A SQL write query
1276 * @param float $runtime Total runtime, including RTT
1277 * @param int $affected Affected row count
1278 */
1279 private function updateTrxWriteQueryTime( $sql, $runtime, $affected ) {
1280 // Whether this is indicative of replica DB runtime (except for RBR or ws_repl)
1281 $indicativeOfReplicaRuntime = true;
1282 if ( $runtime > self::SLOW_WRITE_SEC ) {
1283 $verb = $this->getQueryVerb( $sql );
1284 // insert(), upsert(), replace() are fast unless bulky in size or blocked on locks
1285 if ( $verb === 'INSERT' ) {
1286 $indicativeOfReplicaRuntime = $this->affectedRows() > self::SMALL_WRITE_ROWS;
1287 } elseif ( $verb === 'REPLACE' ) {
1288 $indicativeOfReplicaRuntime = $this->affectedRows() > self::SMALL_WRITE_ROWS / 2;
1289 }
1290 }
1291
1292 $this->trxWriteDuration += $runtime;
1293 $this->trxWriteQueryCount += 1;
1294 $this->trxWriteAffectedRows += $affected;
1295 if ( $indicativeOfReplicaRuntime ) {
1296 $this->trxWriteAdjDuration += $runtime;
1297 $this->trxWriteAdjQueryCount += 1;
1298 }
1299 }
1300
1301 /**
1302 * @param string $sql
1303 * @param string $fname
1304 * @throws DBTransactionStateError
1305 */
1306 private function assertTransactionStatus( $sql, $fname ) {
1307 if ( $this->getQueryVerb( $sql ) === 'ROLLBACK' ) { // transaction/savepoint
1308 return;
1309 }
1310
1311 if ( $this->trxStatus < self::STATUS_TRX_OK ) {
1312 throw new DBTransactionStateError(
1313 $this,
1314 "Cannot execute query from $fname while transaction status is ERROR.",
1315 [],
1316 $this->trxStatusCause
1317 );
1318 } elseif ( $this->trxStatus === self::STATUS_TRX_OK && $this->trxStatusIgnoredCause ) {
1319 list( $iLastError, $iLastErrno, $iFname ) = $this->trxStatusIgnoredCause;
1320 call_user_func( $this->deprecationLogger,
1321 "Caller from $fname ignored an error originally raised from $iFname: " .
1322 "[$iLastErrno] $iLastError"
1323 );
1324 $this->trxStatusIgnoredCause = null;
1325 }
1326 }
1327
1328 /**
1329 * Determine whether or not it is safe to retry queries after a database
1330 * connection is lost
1331 *
1332 * @param string $sql SQL query
1333 * @param bool $priorWritesPending Whether there is a transaction open with
1334 * possible write queries or transaction pre-commit/idle callbacks
1335 * waiting on it to finish.
1336 * @return bool True if it is safe to retry the query, false otherwise
1337 */
1338 private function canRecoverFromDisconnect( $sql, $priorWritesPending ) {
1339 # Transaction dropped; this can mean lost writes, or REPEATABLE-READ snapshots.
1340 # Dropped connections also mean that named locks are automatically released.
1341 # Only allow error suppression in autocommit mode or when the lost transaction
1342 # didn't matter anyway (aside from DBO_TRX snapshot loss).
1343 if ( $this->namedLocksHeld ) {
1344 return false; // possible critical section violation
1345 } elseif ( $this->sessionTempTables ) {
1346 return false; // tables might be queried latter
1347 } elseif ( $sql === 'COMMIT' ) {
1348 return !$priorWritesPending; // nothing written anyway? (T127428)
1349 } elseif ( $sql === 'ROLLBACK' ) {
1350 return true; // transaction lost...which is also what was requested :)
1351 } elseif ( $this->explicitTrxActive() ) {
1352 return false; // don't drop atomocity and explicit snapshots
1353 } elseif ( $priorWritesPending ) {
1354 return false; // prior writes lost from implicit transaction
1355 }
1356
1357 return true;
1358 }
1359
1360 /**
1361 * Clean things up after session (and thus transaction) loss
1362 */
1363 private function handleSessionLoss() {
1364 // Clean up tracking of session-level things...
1365 // https://dev.mysql.com/doc/refman/5.7/en/implicit-commit.html
1366 // https://www.postgresql.org/docs/9.2/static/sql-createtable.html (ignoring ON COMMIT)
1367 $this->sessionTempTables = [];
1368 // https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_get-lock
1369 // https://www.postgresql.org/docs/9.4/static/functions-admin.html#FUNCTIONS-ADVISORY-LOCKS
1370 $this->namedLocksHeld = [];
1371 // Session loss implies transaction loss
1372 $this->handleTransactionLoss();
1373 }
1374
1375 /**
1376 * Clean things up after transaction loss
1377 */
1378 private function handleTransactionLoss() {
1379 $this->trxLevel = 0;
1380 $this->trxAtomicCounter = 0;
1381 $this->trxIdleCallbacks = []; // T67263; transaction already lost
1382 $this->trxPreCommitCallbacks = []; // T67263; transaction already lost
1383 try {
1384 // Handle callbacks in trxEndCallbacks, e.g. onTransactionResolution().
1385 // If callback suppression is set then the array will remain unhandled.
1386 $this->runOnTransactionIdleCallbacks( self::TRIGGER_ROLLBACK );
1387 } catch ( Exception $ex ) {
1388 // Already logged; move on...
1389 }
1390 try {
1391 // Handle callbacks in trxRecurringCallbacks, e.g. setTransactionListener()
1392 $this->runTransactionListenerCallbacks( self::TRIGGER_ROLLBACK );
1393 } catch ( Exception $ex ) {
1394 // Already logged; move on...
1395 }
1396 }
1397
1398 /**
1399 * Checks whether the cause of the error is detected to be a timeout.
1400 *
1401 * It returns false by default, and not all engines support detecting this yet.
1402 * If this returns false, it will be treated as a generic query error.
1403 *
1404 * @param string $error Error text
1405 * @param int $errno Error number
1406 * @return bool
1407 */
1408 protected function wasQueryTimeout( $error, $errno ) {
1409 return false;
1410 }
1411
1412 /**
1413 * Report a query error. Log the error, and if neither the object ignore
1414 * flag nor the $tempIgnore flag is set, throw a DBQueryError.
1415 *
1416 * @param string $error
1417 * @param int $errno
1418 * @param string $sql
1419 * @param string $fname
1420 * @param bool $tempIgnore
1421 * @throws DBQueryError
1422 */
1423 public function reportQueryError( $error, $errno, $sql, $fname, $tempIgnore = false ) {
1424 if ( $tempIgnore ) {
1425 $this->queryLogger->debug( "SQL ERROR (ignored): $error\n" );
1426 } else {
1427 $exception = $this->makeQueryException( $error, $errno, $sql, $fname );
1428
1429 throw $exception;
1430 }
1431 }
1432
1433 /**
1434 * @param string $error
1435 * @param string|int $errno
1436 * @param string $sql
1437 * @param string $fname
1438 * @return DBError
1439 */
1440 private function makeQueryException( $error, $errno, $sql, $fname ) {
1441 $sql1line = mb_substr( str_replace( "\n", "\\n", $sql ), 0, 5 * 1024 );
1442 $this->queryLogger->error(
1443 "{fname}\t{db_server}\t{errno}\t{error}\t{sql1line}",
1444 $this->getLogContext( [
1445 'method' => __METHOD__,
1446 'errno' => $errno,
1447 'error' => $error,
1448 'sql1line' => $sql1line,
1449 'fname' => $fname,
1450 ] )
1451 );
1452 $this->queryLogger->debug( "SQL ERROR: " . $error . "\n" );
1453 $wasQueryTimeout = $this->wasQueryTimeout( $error, $errno );
1454 if ( $wasQueryTimeout ) {
1455 $e = new DBQueryTimeoutError( $this, $error, $errno, $sql, $fname );
1456 } else {
1457 $e = new DBQueryError( $this, $error, $errno, $sql, $fname );
1458 }
1459
1460 return $e;
1461 }
1462
1463 public function freeResult( $res ) {
1464 }
1465
1466 public function selectField(
1467 $table, $var, $cond = '', $fname = __METHOD__, $options = [], $join_conds = []
1468 ) {
1469 if ( $var === '*' ) { // sanity
1470 throw new DBUnexpectedError( $this, "Cannot use a * field: got '$var'" );
1471 }
1472
1473 if ( !is_array( $options ) ) {
1474 $options = [ $options ];
1475 }
1476
1477 $options['LIMIT'] = 1;
1478
1479 $res = $this->select( $table, $var, $cond, $fname, $options, $join_conds );
1480 if ( $res === false || !$this->numRows( $res ) ) {
1481 return false;
1482 }
1483
1484 $row = $this->fetchRow( $res );
1485
1486 if ( $row !== false ) {
1487 return reset( $row );
1488 } else {
1489 return false;
1490 }
1491 }
1492
1493 public function selectFieldValues(
1494 $table, $var, $cond = '', $fname = __METHOD__, $options = [], $join_conds = []
1495 ) {
1496 if ( $var === '*' ) { // sanity
1497 throw new DBUnexpectedError( $this, "Cannot use a * field" );
1498 } elseif ( !is_string( $var ) ) { // sanity
1499 throw new DBUnexpectedError( $this, "Cannot use an array of fields" );
1500 }
1501
1502 if ( !is_array( $options ) ) {
1503 $options = [ $options ];
1504 }
1505
1506 $res = $this->select( $table, [ 'value' => $var ], $cond, $fname, $options, $join_conds );
1507 if ( $res === false ) {
1508 return false;
1509 }
1510
1511 $values = [];
1512 foreach ( $res as $row ) {
1513 $values[] = $row->value;
1514 }
1515
1516 return $values;
1517 }
1518
1519 /**
1520 * Returns an optional USE INDEX clause to go after the table, and a
1521 * string to go at the end of the query.
1522 *
1523 * @param array $options Associative array of options to be turned into
1524 * an SQL query, valid keys are listed in the function.
1525 * @return array
1526 * @see Database::select()
1527 */
1528 protected function makeSelectOptions( $options ) {
1529 $preLimitTail = $postLimitTail = '';
1530 $startOpts = '';
1531
1532 $noKeyOptions = [];
1533
1534 foreach ( $options as $key => $option ) {
1535 if ( is_numeric( $key ) ) {
1536 $noKeyOptions[$option] = true;
1537 }
1538 }
1539
1540 $preLimitTail .= $this->makeGroupByWithHaving( $options );
1541
1542 $preLimitTail .= $this->makeOrderBy( $options );
1543
1544 if ( isset( $noKeyOptions['FOR UPDATE'] ) ) {
1545 $postLimitTail .= ' FOR UPDATE';
1546 }
1547
1548 if ( isset( $noKeyOptions['LOCK IN SHARE MODE'] ) ) {
1549 $postLimitTail .= ' LOCK IN SHARE MODE';
1550 }
1551
1552 if ( isset( $noKeyOptions['DISTINCT'] ) || isset( $noKeyOptions['DISTINCTROW'] ) ) {
1553 $startOpts .= 'DISTINCT';
1554 }
1555
1556 # Various MySQL extensions
1557 if ( isset( $noKeyOptions['STRAIGHT_JOIN'] ) ) {
1558 $startOpts .= ' /*! STRAIGHT_JOIN */';
1559 }
1560
1561 if ( isset( $noKeyOptions['HIGH_PRIORITY'] ) ) {
1562 $startOpts .= ' HIGH_PRIORITY';
1563 }
1564
1565 if ( isset( $noKeyOptions['SQL_BIG_RESULT'] ) ) {
1566 $startOpts .= ' SQL_BIG_RESULT';
1567 }
1568
1569 if ( isset( $noKeyOptions['SQL_BUFFER_RESULT'] ) ) {
1570 $startOpts .= ' SQL_BUFFER_RESULT';
1571 }
1572
1573 if ( isset( $noKeyOptions['SQL_SMALL_RESULT'] ) ) {
1574 $startOpts .= ' SQL_SMALL_RESULT';
1575 }
1576
1577 if ( isset( $noKeyOptions['SQL_CALC_FOUND_ROWS'] ) ) {
1578 $startOpts .= ' SQL_CALC_FOUND_ROWS';
1579 }
1580
1581 if ( isset( $noKeyOptions['SQL_CACHE'] ) ) {
1582 $startOpts .= ' SQL_CACHE';
1583 }
1584
1585 if ( isset( $noKeyOptions['SQL_NO_CACHE'] ) ) {
1586 $startOpts .= ' SQL_NO_CACHE';
1587 }
1588
1589 if ( isset( $options['USE INDEX'] ) && is_string( $options['USE INDEX'] ) ) {
1590 $useIndex = $this->useIndexClause( $options['USE INDEX'] );
1591 } else {
1592 $useIndex = '';
1593 }
1594 if ( isset( $options['IGNORE INDEX'] ) && is_string( $options['IGNORE INDEX'] ) ) {
1595 $ignoreIndex = $this->ignoreIndexClause( $options['IGNORE INDEX'] );
1596 } else {
1597 $ignoreIndex = '';
1598 }
1599
1600 return [ $startOpts, $useIndex, $preLimitTail, $postLimitTail, $ignoreIndex ];
1601 }
1602
1603 /**
1604 * Returns an optional GROUP BY with an optional HAVING
1605 *
1606 * @param array $options Associative array of options
1607 * @return string
1608 * @see Database::select()
1609 * @since 1.21
1610 */
1611 protected function makeGroupByWithHaving( $options ) {
1612 $sql = '';
1613 if ( isset( $options['GROUP BY'] ) ) {
1614 $gb = is_array( $options['GROUP BY'] )
1615 ? implode( ',', $options['GROUP BY'] )
1616 : $options['GROUP BY'];
1617 $sql .= ' GROUP BY ' . $gb;
1618 }
1619 if ( isset( $options['HAVING'] ) ) {
1620 $having = is_array( $options['HAVING'] )
1621 ? $this->makeList( $options['HAVING'], self::LIST_AND )
1622 : $options['HAVING'];
1623 $sql .= ' HAVING ' . $having;
1624 }
1625
1626 return $sql;
1627 }
1628
1629 /**
1630 * Returns an optional ORDER BY
1631 *
1632 * @param array $options Associative array of options
1633 * @return string
1634 * @see Database::select()
1635 * @since 1.21
1636 */
1637 protected function makeOrderBy( $options ) {
1638 if ( isset( $options['ORDER BY'] ) ) {
1639 $ob = is_array( $options['ORDER BY'] )
1640 ? implode( ',', $options['ORDER BY'] )
1641 : $options['ORDER BY'];
1642
1643 return ' ORDER BY ' . $ob;
1644 }
1645
1646 return '';
1647 }
1648
1649 public function select( $table, $vars, $conds = '', $fname = __METHOD__,
1650 $options = [], $join_conds = [] ) {
1651 $sql = $this->selectSQLText( $table, $vars, $conds, $fname, $options, $join_conds );
1652
1653 return $this->query( $sql, $fname );
1654 }
1655
1656 public function selectSQLText( $table, $vars, $conds = '', $fname = __METHOD__,
1657 $options = [], $join_conds = []
1658 ) {
1659 if ( is_array( $vars ) ) {
1660 $vars = implode( ',', $this->fieldNamesWithAlias( $vars ) );
1661 }
1662
1663 $options = (array)$options;
1664 $useIndexes = ( isset( $options['USE INDEX'] ) && is_array( $options['USE INDEX'] ) )
1665 ? $options['USE INDEX']
1666 : [];
1667 $ignoreIndexes = (
1668 isset( $options['IGNORE INDEX'] ) &&
1669 is_array( $options['IGNORE INDEX'] )
1670 )
1671 ? $options['IGNORE INDEX']
1672 : [];
1673
1674 if ( is_array( $table ) ) {
1675 $from = ' FROM ' .
1676 $this->tableNamesWithIndexClauseOrJOIN(
1677 $table, $useIndexes, $ignoreIndexes, $join_conds );
1678 } elseif ( $table != '' ) {
1679 $from = ' FROM ' .
1680 $this->tableNamesWithIndexClauseOrJOIN(
1681 [ $table ], $useIndexes, $ignoreIndexes, [] );
1682 } else {
1683 $from = '';
1684 }
1685
1686 list( $startOpts, $useIndex, $preLimitTail, $postLimitTail, $ignoreIndex ) =
1687 $this->makeSelectOptions( $options );
1688
1689 if ( is_array( $conds ) ) {
1690 $conds = $this->makeList( $conds, self::LIST_AND );
1691 }
1692
1693 if ( $conds === null || $conds === false ) {
1694 $this->queryLogger->warning(
1695 __METHOD__
1696 . ' called from '
1697 . $fname
1698 . ' with incorrect parameters: $conds must be a string or an array'
1699 );
1700 $conds = '';
1701 }
1702
1703 if ( $conds === '' ) {
1704 $sql = "SELECT $startOpts $vars $from $useIndex $ignoreIndex $preLimitTail";
1705 } elseif ( is_string( $conds ) ) {
1706 $sql = "SELECT $startOpts $vars $from $useIndex $ignoreIndex " .
1707 "WHERE $conds $preLimitTail";
1708 } else {
1709 throw new DBUnexpectedError( $this, __METHOD__ . ' called with incorrect parameters' );
1710 }
1711
1712 if ( isset( $options['LIMIT'] ) ) {
1713 $sql = $this->limitResult( $sql, $options['LIMIT'],
1714 isset( $options['OFFSET'] ) ? $options['OFFSET'] : false );
1715 }
1716 $sql = "$sql $postLimitTail";
1717
1718 if ( isset( $options['EXPLAIN'] ) ) {
1719 $sql = 'EXPLAIN ' . $sql;
1720 }
1721
1722 return $sql;
1723 }
1724
1725 public function selectRow( $table, $vars, $conds, $fname = __METHOD__,
1726 $options = [], $join_conds = []
1727 ) {
1728 $options = (array)$options;
1729 $options['LIMIT'] = 1;
1730 $res = $this->select( $table, $vars, $conds, $fname, $options, $join_conds );
1731
1732 if ( $res === false ) {
1733 return false;
1734 }
1735
1736 if ( !$this->numRows( $res ) ) {
1737 return false;
1738 }
1739
1740 $obj = $this->fetchObject( $res );
1741
1742 return $obj;
1743 }
1744
1745 public function estimateRowCount(
1746 $table, $var = '*', $conds = '', $fname = __METHOD__, $options = [], $join_conds = []
1747 ) {
1748 $conds = $this->normalizeConditions( $conds, $fname );
1749 $column = $this->extractSingleFieldFromList( $var );
1750 if ( is_string( $column ) && !in_array( $column, [ '*', '1' ] ) ) {
1751 $conds[] = "$column IS NOT NULL";
1752 }
1753
1754 $res = $this->select(
1755 $table, [ 'rowcount' => 'COUNT(*)' ], $conds, $fname, $options, $join_conds
1756 );
1757 $row = $res ? $this->fetchRow( $res ) : [];
1758
1759 return isset( $row['rowcount'] ) ? (int)$row['rowcount'] : 0;
1760 }
1761
1762 public function selectRowCount(
1763 $tables, $var = '*', $conds = '', $fname = __METHOD__, $options = [], $join_conds = []
1764 ) {
1765 $conds = $this->normalizeConditions( $conds, $fname );
1766 $column = $this->extractSingleFieldFromList( $var );
1767 if ( is_string( $column ) && !in_array( $column, [ '*', '1' ] ) ) {
1768 $conds[] = "$column IS NOT NULL";
1769 }
1770
1771 $res = $this->select(
1772 [
1773 'tmp_count' => $this->buildSelectSubquery(
1774 $tables,
1775 '1',
1776 $conds,
1777 $fname,
1778 $options,
1779 $join_conds
1780 )
1781 ],
1782 [ 'rowcount' => 'COUNT(*)' ],
1783 [],
1784 $fname
1785 );
1786 $row = $res ? $this->fetchRow( $res ) : [];
1787
1788 return isset( $row['rowcount'] ) ? (int)$row['rowcount'] : 0;
1789 }
1790
1791 /**
1792 * @param array|string $conds
1793 * @param string $fname
1794 * @return array
1795 */
1796 final protected function normalizeConditions( $conds, $fname ) {
1797 if ( $conds === null || $conds === false ) {
1798 $this->queryLogger->warning(
1799 __METHOD__
1800 . ' called from '
1801 . $fname
1802 . ' with incorrect parameters: $conds must be a string or an array'
1803 );
1804 $conds = '';
1805 }
1806
1807 if ( !is_array( $conds ) ) {
1808 $conds = ( $conds === '' ) ? [] : [ $conds ];
1809 }
1810
1811 return $conds;
1812 }
1813
1814 /**
1815 * @param array|string $var Field parameter in the style of select()
1816 * @return string|null Column name or null; ignores aliases
1817 * @throws DBUnexpectedError Errors out if multiple columns are given
1818 */
1819 final protected function extractSingleFieldFromList( $var ) {
1820 if ( is_array( $var ) ) {
1821 if ( !$var ) {
1822 $column = null;
1823 } elseif ( count( $var ) == 1 ) {
1824 $column = isset( $var[0] ) ? $var[0] : reset( $var );
1825 } else {
1826 throw new DBUnexpectedError( $this, __METHOD__ . ': got multiple columns.' );
1827 }
1828 } else {
1829 $column = $var;
1830 }
1831
1832 return $column;
1833 }
1834
1835 /**
1836 * Removes most variables from an SQL query and replaces them with X or N for numbers.
1837 * It's only slightly flawed. Don't use for anything important.
1838 *
1839 * @param string $sql A SQL Query
1840 *
1841 * @return string
1842 */
1843 protected static function generalizeSQL( $sql ) {
1844 # This does the same as the regexp below would do, but in such a way
1845 # as to avoid crashing php on some large strings.
1846 # $sql = preg_replace( "/'([^\\\\']|\\\\.)*'|\"([^\\\\\"]|\\\\.)*\"/", "'X'", $sql );
1847
1848 $sql = str_replace( "\\\\", '', $sql );
1849 $sql = str_replace( "\\'", '', $sql );
1850 $sql = str_replace( "\\\"", '', $sql );
1851 $sql = preg_replace( "/'.*'/s", "'X'", $sql );
1852 $sql = preg_replace( '/".*"/s', "'X'", $sql );
1853
1854 # All newlines, tabs, etc replaced by single space
1855 $sql = preg_replace( '/\s+/', ' ', $sql );
1856
1857 # All numbers => N,
1858 # except the ones surrounded by characters, e.g. l10n
1859 $sql = preg_replace( '/-?\d+(,-?\d+)+/s', 'N,...,N', $sql );
1860 $sql = preg_replace( '/(?<![a-zA-Z])-?\d+(?![a-zA-Z])/s', 'N', $sql );
1861
1862 return $sql;
1863 }
1864
1865 public function fieldExists( $table, $field, $fname = __METHOD__ ) {
1866 $info = $this->fieldInfo( $table, $field );
1867
1868 return (bool)$info;
1869 }
1870
1871 public function indexExists( $table, $index, $fname = __METHOD__ ) {
1872 if ( !$this->tableExists( $table ) ) {
1873 return null;
1874 }
1875
1876 $info = $this->indexInfo( $table, $index, $fname );
1877 if ( is_null( $info ) ) {
1878 return null;
1879 } else {
1880 return $info !== false;
1881 }
1882 }
1883
1884 public function tableExists( $table, $fname = __METHOD__ ) {
1885 $tableRaw = $this->tableName( $table, 'raw' );
1886 if ( isset( $this->sessionTempTables[$tableRaw] ) ) {
1887 return true; // already known to exist
1888 }
1889
1890 $table = $this->tableName( $table );
1891 $ignoreErrors = true;
1892 $res = $this->query( "SELECT 1 FROM $table LIMIT 1", $fname, $ignoreErrors );
1893
1894 return (bool)$res;
1895 }
1896
1897 public function indexUnique( $table, $index ) {
1898 $indexInfo = $this->indexInfo( $table, $index );
1899
1900 if ( !$indexInfo ) {
1901 return null;
1902 }
1903
1904 return !$indexInfo[0]->Non_unique;
1905 }
1906
1907 /**
1908 * Helper for Database::insert().
1909 *
1910 * @param array $options
1911 * @return string
1912 */
1913 protected function makeInsertOptions( $options ) {
1914 return implode( ' ', $options );
1915 }
1916
1917 public function insert( $table, $a, $fname = __METHOD__, $options = [] ) {
1918 # No rows to insert, easy just return now
1919 if ( !count( $a ) ) {
1920 return true;
1921 }
1922
1923 $table = $this->tableName( $table );
1924
1925 if ( !is_array( $options ) ) {
1926 $options = [ $options ];
1927 }
1928
1929 $fh = null;
1930 if ( isset( $options['fileHandle'] ) ) {
1931 $fh = $options['fileHandle'];
1932 }
1933 $options = $this->makeInsertOptions( $options );
1934
1935 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
1936 $multi = true;
1937 $keys = array_keys( $a[0] );
1938 } else {
1939 $multi = false;
1940 $keys = array_keys( $a );
1941 }
1942
1943 $sql = 'INSERT ' . $options .
1944 " INTO $table (" . implode( ',', $keys ) . ') VALUES ';
1945
1946 if ( $multi ) {
1947 $first = true;
1948 foreach ( $a as $row ) {
1949 if ( $first ) {
1950 $first = false;
1951 } else {
1952 $sql .= ',';
1953 }
1954 $sql .= '(' . $this->makeList( $row ) . ')';
1955 }
1956 } else {
1957 $sql .= '(' . $this->makeList( $a ) . ')';
1958 }
1959
1960 if ( $fh !== null && false === fwrite( $fh, $sql ) ) {
1961 return false;
1962 } elseif ( $fh !== null ) {
1963 return true;
1964 }
1965
1966 return (bool)$this->query( $sql, $fname );
1967 }
1968
1969 /**
1970 * Make UPDATE options array for Database::makeUpdateOptions
1971 *
1972 * @param array $options
1973 * @return array
1974 */
1975 protected function makeUpdateOptionsArray( $options ) {
1976 if ( !is_array( $options ) ) {
1977 $options = [ $options ];
1978 }
1979
1980 $opts = [];
1981
1982 if ( in_array( 'IGNORE', $options ) ) {
1983 $opts[] = 'IGNORE';
1984 }
1985
1986 return $opts;
1987 }
1988
1989 /**
1990 * Make UPDATE options for the Database::update function
1991 *
1992 * @param array $options The options passed to Database::update
1993 * @return string
1994 */
1995 protected function makeUpdateOptions( $options ) {
1996 $opts = $this->makeUpdateOptionsArray( $options );
1997
1998 return implode( ' ', $opts );
1999 }
2000
2001 public function update( $table, $values, $conds, $fname = __METHOD__, $options = [] ) {
2002 $table = $this->tableName( $table );
2003 $opts = $this->makeUpdateOptions( $options );
2004 $sql = "UPDATE $opts $table SET " . $this->makeList( $values, self::LIST_SET );
2005
2006 if ( $conds !== [] && $conds !== '*' ) {
2007 $sql .= " WHERE " . $this->makeList( $conds, self::LIST_AND );
2008 }
2009
2010 return (bool)$this->query( $sql, $fname );
2011 }
2012
2013 public function makeList( $a, $mode = self::LIST_COMMA ) {
2014 if ( !is_array( $a ) ) {
2015 throw new DBUnexpectedError( $this, __METHOD__ . ' called with incorrect parameters' );
2016 }
2017
2018 $first = true;
2019 $list = '';
2020
2021 foreach ( $a as $field => $value ) {
2022 if ( !$first ) {
2023 if ( $mode == self::LIST_AND ) {
2024 $list .= ' AND ';
2025 } elseif ( $mode == self::LIST_OR ) {
2026 $list .= ' OR ';
2027 } else {
2028 $list .= ',';
2029 }
2030 } else {
2031 $first = false;
2032 }
2033
2034 if ( ( $mode == self::LIST_AND || $mode == self::LIST_OR ) && is_numeric( $field ) ) {
2035 $list .= "($value)";
2036 } elseif ( $mode == self::LIST_SET && is_numeric( $field ) ) {
2037 $list .= "$value";
2038 } elseif (
2039 ( $mode == self::LIST_AND || $mode == self::LIST_OR ) && is_array( $value )
2040 ) {
2041 // Remove null from array to be handled separately if found
2042 $includeNull = false;
2043 foreach ( array_keys( $value, null, true ) as $nullKey ) {
2044 $includeNull = true;
2045 unset( $value[$nullKey] );
2046 }
2047 if ( count( $value ) == 0 && !$includeNull ) {
2048 throw new InvalidArgumentException(
2049 __METHOD__ . ": empty input for field $field" );
2050 } elseif ( count( $value ) == 0 ) {
2051 // only check if $field is null
2052 $list .= "$field IS NULL";
2053 } else {
2054 // IN clause contains at least one valid element
2055 if ( $includeNull ) {
2056 // Group subconditions to ensure correct precedence
2057 $list .= '(';
2058 }
2059 if ( count( $value ) == 1 ) {
2060 // Special-case single values, as IN isn't terribly efficient
2061 // Don't necessarily assume the single key is 0; we don't
2062 // enforce linear numeric ordering on other arrays here.
2063 $value = array_values( $value )[0];
2064 $list .= $field . " = " . $this->addQuotes( $value );
2065 } else {
2066 $list .= $field . " IN (" . $this->makeList( $value ) . ") ";
2067 }
2068 // if null present in array, append IS NULL
2069 if ( $includeNull ) {
2070 $list .= " OR $field IS NULL)";
2071 }
2072 }
2073 } elseif ( $value === null ) {
2074 if ( $mode == self::LIST_AND || $mode == self::LIST_OR ) {
2075 $list .= "$field IS ";
2076 } elseif ( $mode == self::LIST_SET ) {
2077 $list .= "$field = ";
2078 }
2079 $list .= 'NULL';
2080 } else {
2081 if (
2082 $mode == self::LIST_AND || $mode == self::LIST_OR || $mode == self::LIST_SET
2083 ) {
2084 $list .= "$field = ";
2085 }
2086 $list .= $mode == self::LIST_NAMES ? $value : $this->addQuotes( $value );
2087 }
2088 }
2089
2090 return $list;
2091 }
2092
2093 public function makeWhereFrom2d( $data, $baseKey, $subKey ) {
2094 $conds = [];
2095
2096 foreach ( $data as $base => $sub ) {
2097 if ( count( $sub ) ) {
2098 $conds[] = $this->makeList(
2099 [ $baseKey => $base, $subKey => array_keys( $sub ) ],
2100 self::LIST_AND );
2101 }
2102 }
2103
2104 if ( $conds ) {
2105 return $this->makeList( $conds, self::LIST_OR );
2106 } else {
2107 // Nothing to search for...
2108 return false;
2109 }
2110 }
2111
2112 public function aggregateValue( $valuedata, $valuename = 'value' ) {
2113 return $valuename;
2114 }
2115
2116 public function bitNot( $field ) {
2117 return "(~$field)";
2118 }
2119
2120 public function bitAnd( $fieldLeft, $fieldRight ) {
2121 return "($fieldLeft & $fieldRight)";
2122 }
2123
2124 public function bitOr( $fieldLeft, $fieldRight ) {
2125 return "($fieldLeft | $fieldRight)";
2126 }
2127
2128 public function buildConcat( $stringList ) {
2129 return 'CONCAT(' . implode( ',', $stringList ) . ')';
2130 }
2131
2132 public function buildGroupConcatField(
2133 $delim, $table, $field, $conds = '', $join_conds = []
2134 ) {
2135 $fld = "GROUP_CONCAT($field SEPARATOR " . $this->addQuotes( $delim ) . ')';
2136
2137 return '(' . $this->selectSQLText( $table, $fld, $conds, null, [], $join_conds ) . ')';
2138 }
2139
2140 public function buildSubstring( $input, $startPosition, $length = null ) {
2141 $this->assertBuildSubstringParams( $startPosition, $length );
2142 $functionBody = "$input FROM $startPosition";
2143 if ( $length !== null ) {
2144 $functionBody .= " FOR $length";
2145 }
2146 return 'SUBSTRING(' . $functionBody . ')';
2147 }
2148
2149 /**
2150 * Check type and bounds for parameters to self::buildSubstring()
2151 *
2152 * All supported databases have substring functions that behave the same for
2153 * positive $startPosition and non-negative $length, but behaviors differ when
2154 * given 0 or negative $startPosition or negative $length. The simplest
2155 * solution to that is to just forbid those values.
2156 *
2157 * @param int $startPosition
2158 * @param int|null $length
2159 * @since 1.31
2160 */
2161 protected function assertBuildSubstringParams( $startPosition, $length ) {
2162 if ( !is_int( $startPosition ) || $startPosition <= 0 ) {
2163 throw new InvalidArgumentException(
2164 '$startPosition must be a positive integer'
2165 );
2166 }
2167 if ( !( is_int( $length ) && $length >= 0 || $length === null ) ) {
2168 throw new InvalidArgumentException(
2169 '$length must be null or an integer greater than or equal to 0'
2170 );
2171 }
2172 }
2173
2174 public function buildStringCast( $field ) {
2175 return $field;
2176 }
2177
2178 public function buildIntegerCast( $field ) {
2179 return 'CAST( ' . $field . ' AS INTEGER )';
2180 }
2181
2182 public function buildSelectSubquery(
2183 $table, $vars, $conds = '', $fname = __METHOD__,
2184 $options = [], $join_conds = []
2185 ) {
2186 return new Subquery(
2187 $this->selectSQLText( $table, $vars, $conds, $fname, $options, $join_conds )
2188 );
2189 }
2190
2191 public function databasesAreIndependent() {
2192 return false;
2193 }
2194
2195 public function selectDB( $db ) {
2196 # Stub. Shouldn't cause serious problems if it's not overridden, but
2197 # if your database engine supports a concept similar to MySQL's
2198 # databases you may as well.
2199 $this->dbName = $db;
2200
2201 return true;
2202 }
2203
2204 public function getDBname() {
2205 return $this->dbName;
2206 }
2207
2208 public function getServer() {
2209 return $this->server;
2210 }
2211
2212 public function tableName( $name, $format = 'quoted' ) {
2213 if ( $name instanceof Subquery ) {
2214 throw new DBUnexpectedError(
2215 $this,
2216 __METHOD__ . ': got Subquery instance when expecting a string.'
2217 );
2218 }
2219
2220 # Skip the entire process when we have a string quoted on both ends.
2221 # Note that we check the end so that we will still quote any use of
2222 # use of `database`.table. But won't break things if someone wants
2223 # to query a database table with a dot in the name.
2224 if ( $this->isQuotedIdentifier( $name ) ) {
2225 return $name;
2226 }
2227
2228 # Lets test for any bits of text that should never show up in a table
2229 # name. Basically anything like JOIN or ON which are actually part of
2230 # SQL queries, but may end up inside of the table value to combine
2231 # sql. Such as how the API is doing.
2232 # Note that we use a whitespace test rather than a \b test to avoid
2233 # any remote case where a word like on may be inside of a table name
2234 # surrounded by symbols which may be considered word breaks.
2235 if ( preg_match( '/(^|\s)(DISTINCT|JOIN|ON|AS)(\s|$)/i', $name ) !== 0 ) {
2236 $this->queryLogger->warning(
2237 __METHOD__ . ": use of subqueries is not supported this way.",
2238 [ 'trace' => ( new RuntimeException() )->getTraceAsString() ]
2239 );
2240
2241 return $name;
2242 }
2243
2244 # Split database and table into proper variables.
2245 list( $database, $schema, $prefix, $table ) = $this->qualifiedTableComponents( $name );
2246
2247 # Quote $table and apply the prefix if not quoted.
2248 # $tableName might be empty if this is called from Database::replaceVars()
2249 $tableName = "{$prefix}{$table}";
2250 if ( $format === 'quoted'
2251 && !$this->isQuotedIdentifier( $tableName )
2252 && $tableName !== ''
2253 ) {
2254 $tableName = $this->addIdentifierQuotes( $tableName );
2255 }
2256
2257 # Quote $schema and $database and merge them with the table name if needed
2258 $tableName = $this->prependDatabaseOrSchema( $schema, $tableName, $format );
2259 $tableName = $this->prependDatabaseOrSchema( $database, $tableName, $format );
2260
2261 return $tableName;
2262 }
2263
2264 /**
2265 * Get the table components needed for a query given the currently selected database
2266 *
2267 * @param string $name Table name in the form of db.schema.table, db.table, or table
2268 * @return array (DB name or "" for default, schema name, table prefix, table name)
2269 */
2270 protected function qualifiedTableComponents( $name ) {
2271 # We reverse the explode so that database.table and table both output the correct table.
2272 $dbDetails = explode( '.', $name, 3 );
2273 if ( count( $dbDetails ) == 3 ) {
2274 list( $database, $schema, $table ) = $dbDetails;
2275 # We don't want any prefix added in this case
2276 $prefix = '';
2277 } elseif ( count( $dbDetails ) == 2 ) {
2278 list( $database, $table ) = $dbDetails;
2279 # We don't want any prefix added in this case
2280 $prefix = '';
2281 # In dbs that support it, $database may actually be the schema
2282 # but that doesn't affect any of the functionality here
2283 $schema = '';
2284 } else {
2285 list( $table ) = $dbDetails;
2286 if ( isset( $this->tableAliases[$table] ) ) {
2287 $database = $this->tableAliases[$table]['dbname'];
2288 $schema = is_string( $this->tableAliases[$table]['schema'] )
2289 ? $this->tableAliases[$table]['schema']
2290 : $this->schema;
2291 $prefix = is_string( $this->tableAliases[$table]['prefix'] )
2292 ? $this->tableAliases[$table]['prefix']
2293 : $this->tablePrefix;
2294 } else {
2295 $database = '';
2296 $schema = $this->schema; # Default schema
2297 $prefix = $this->tablePrefix; # Default prefix
2298 }
2299 }
2300
2301 return [ $database, $schema, $prefix, $table ];
2302 }
2303
2304 /**
2305 * @param string|null $namespace Database or schema
2306 * @param string $relation Name of table, view, sequence, etc...
2307 * @param string $format One of (raw, quoted)
2308 * @return string Relation name with quoted and merged $namespace as needed
2309 */
2310 private function prependDatabaseOrSchema( $namespace, $relation, $format ) {
2311 if ( strlen( $namespace ) ) {
2312 if ( $format === 'quoted' && !$this->isQuotedIdentifier( $namespace ) ) {
2313 $namespace = $this->addIdentifierQuotes( $namespace );
2314 }
2315 $relation = $namespace . '.' . $relation;
2316 }
2317
2318 return $relation;
2319 }
2320
2321 public function tableNames() {
2322 $inArray = func_get_args();
2323 $retVal = [];
2324
2325 foreach ( $inArray as $name ) {
2326 $retVal[$name] = $this->tableName( $name );
2327 }
2328
2329 return $retVal;
2330 }
2331
2332 public function tableNamesN() {
2333 $inArray = func_get_args();
2334 $retVal = [];
2335
2336 foreach ( $inArray as $name ) {
2337 $retVal[] = $this->tableName( $name );
2338 }
2339
2340 return $retVal;
2341 }
2342
2343 /**
2344 * Get an aliased table name
2345 *
2346 * This returns strings like "tableName AS newTableName" for aliased tables
2347 * and "(SELECT * from tableA) newTablename" for subqueries (e.g. derived tables)
2348 *
2349 * @see Database::tableName()
2350 * @param string|Subquery $table Table name or object with a 'sql' field
2351 * @param string|bool $alias Table alias (optional)
2352 * @return string SQL name for aliased table. Will not alias a table to its own name
2353 */
2354 protected function tableNameWithAlias( $table, $alias = false ) {
2355 if ( is_string( $table ) ) {
2356 $quotedTable = $this->tableName( $table );
2357 } elseif ( $table instanceof Subquery ) {
2358 $quotedTable = (string)$table;
2359 } else {
2360 throw new InvalidArgumentException( "Table must be a string or Subquery." );
2361 }
2362
2363 if ( !strlen( $alias ) || $alias === $table ) {
2364 if ( $table instanceof Subquery ) {
2365 throw new InvalidArgumentException( "Subquery table missing alias." );
2366 }
2367
2368 return $quotedTable;
2369 } else {
2370 return $quotedTable . ' ' . $this->addIdentifierQuotes( $alias );
2371 }
2372 }
2373
2374 /**
2375 * Gets an array of aliased table names
2376 *
2377 * @param array $tables [ [alias] => table ]
2378 * @return string[] See tableNameWithAlias()
2379 */
2380 protected function tableNamesWithAlias( $tables ) {
2381 $retval = [];
2382 foreach ( $tables as $alias => $table ) {
2383 if ( is_numeric( $alias ) ) {
2384 $alias = $table;
2385 }
2386 $retval[] = $this->tableNameWithAlias( $table, $alias );
2387 }
2388
2389 return $retval;
2390 }
2391
2392 /**
2393 * Get an aliased field name
2394 * e.g. fieldName AS newFieldName
2395 *
2396 * @param string $name Field name
2397 * @param string|bool $alias Alias (optional)
2398 * @return string SQL name for aliased field. Will not alias a field to its own name
2399 */
2400 protected function fieldNameWithAlias( $name, $alias = false ) {
2401 if ( !$alias || (string)$alias === (string)$name ) {
2402 return $name;
2403 } else {
2404 return $name . ' AS ' . $this->addIdentifierQuotes( $alias ); // PostgreSQL needs AS
2405 }
2406 }
2407
2408 /**
2409 * Gets an array of aliased field names
2410 *
2411 * @param array $fields [ [alias] => field ]
2412 * @return string[] See fieldNameWithAlias()
2413 */
2414 protected function fieldNamesWithAlias( $fields ) {
2415 $retval = [];
2416 foreach ( $fields as $alias => $field ) {
2417 if ( is_numeric( $alias ) ) {
2418 $alias = $field;
2419 }
2420 $retval[] = $this->fieldNameWithAlias( $field, $alias );
2421 }
2422
2423 return $retval;
2424 }
2425
2426 /**
2427 * Get the aliased table name clause for a FROM clause
2428 * which might have a JOIN and/or USE INDEX or IGNORE INDEX clause
2429 *
2430 * @param array $tables ( [alias] => table )
2431 * @param array $use_index Same as for select()
2432 * @param array $ignore_index Same as for select()
2433 * @param array $join_conds Same as for select()
2434 * @return string
2435 */
2436 protected function tableNamesWithIndexClauseOrJOIN(
2437 $tables, $use_index = [], $ignore_index = [], $join_conds = []
2438 ) {
2439 $ret = [];
2440 $retJOIN = [];
2441 $use_index = (array)$use_index;
2442 $ignore_index = (array)$ignore_index;
2443 $join_conds = (array)$join_conds;
2444
2445 foreach ( $tables as $alias => $table ) {
2446 if ( !is_string( $alias ) ) {
2447 // No alias? Set it equal to the table name
2448 $alias = $table;
2449 }
2450
2451 if ( is_array( $table ) ) {
2452 // A parenthesized group
2453 if ( count( $table ) > 1 ) {
2454 $joinedTable = '(' .
2455 $this->tableNamesWithIndexClauseOrJOIN(
2456 $table, $use_index, $ignore_index, $join_conds ) . ')';
2457 } else {
2458 // Degenerate case
2459 $innerTable = reset( $table );
2460 $innerAlias = key( $table );
2461 $joinedTable = $this->tableNameWithAlias(
2462 $innerTable,
2463 is_string( $innerAlias ) ? $innerAlias : $innerTable
2464 );
2465 }
2466 } else {
2467 $joinedTable = $this->tableNameWithAlias( $table, $alias );
2468 }
2469
2470 // Is there a JOIN clause for this table?
2471 if ( isset( $join_conds[$alias] ) ) {
2472 list( $joinType, $conds ) = $join_conds[$alias];
2473 $tableClause = $joinType;
2474 $tableClause .= ' ' . $joinedTable;
2475 if ( isset( $use_index[$alias] ) ) { // has USE INDEX?
2476 $use = $this->useIndexClause( implode( ',', (array)$use_index[$alias] ) );
2477 if ( $use != '' ) {
2478 $tableClause .= ' ' . $use;
2479 }
2480 }
2481 if ( isset( $ignore_index[$alias] ) ) { // has IGNORE INDEX?
2482 $ignore = $this->ignoreIndexClause(
2483 implode( ',', (array)$ignore_index[$alias] ) );
2484 if ( $ignore != '' ) {
2485 $tableClause .= ' ' . $ignore;
2486 }
2487 }
2488 $on = $this->makeList( (array)$conds, self::LIST_AND );
2489 if ( $on != '' ) {
2490 $tableClause .= ' ON (' . $on . ')';
2491 }
2492
2493 $retJOIN[] = $tableClause;
2494 } elseif ( isset( $use_index[$alias] ) ) {
2495 // Is there an INDEX clause for this table?
2496 $tableClause = $joinedTable;
2497 $tableClause .= ' ' . $this->useIndexClause(
2498 implode( ',', (array)$use_index[$alias] )
2499 );
2500
2501 $ret[] = $tableClause;
2502 } elseif ( isset( $ignore_index[$alias] ) ) {
2503 // Is there an INDEX clause for this table?
2504 $tableClause = $joinedTable;
2505 $tableClause .= ' ' . $this->ignoreIndexClause(
2506 implode( ',', (array)$ignore_index[$alias] )
2507 );
2508
2509 $ret[] = $tableClause;
2510 } else {
2511 $tableClause = $joinedTable;
2512
2513 $ret[] = $tableClause;
2514 }
2515 }
2516
2517 // We can't separate explicit JOIN clauses with ',', use ' ' for those
2518 $implicitJoins = $ret ? implode( ',', $ret ) : "";
2519 $explicitJoins = $retJOIN ? implode( ' ', $retJOIN ) : "";
2520
2521 // Compile our final table clause
2522 return implode( ' ', [ $implicitJoins, $explicitJoins ] );
2523 }
2524
2525 /**
2526 * Allows for index remapping in queries where this is not consistent across DBMS
2527 *
2528 * @param string $index
2529 * @return string
2530 */
2531 protected function indexName( $index ) {
2532 return isset( $this->indexAliases[$index] )
2533 ? $this->indexAliases[$index]
2534 : $index;
2535 }
2536
2537 public function addQuotes( $s ) {
2538 if ( $s instanceof Blob ) {
2539 $s = $s->fetch();
2540 }
2541 if ( $s === null ) {
2542 return 'NULL';
2543 } elseif ( is_bool( $s ) ) {
2544 return (int)$s;
2545 } else {
2546 # This will also quote numeric values. This should be harmless,
2547 # and protects against weird problems that occur when they really
2548 # _are_ strings such as article titles and string->number->string
2549 # conversion is not 1:1.
2550 return "'" . $this->strencode( $s ) . "'";
2551 }
2552 }
2553
2554 /**
2555 * Quotes an identifier using `backticks` or "double quotes" depending on the database type.
2556 * MySQL uses `backticks` while basically everything else uses double quotes.
2557 * Since MySQL is the odd one out here the double quotes are our generic
2558 * and we implement backticks in DatabaseMysqlBase.
2559 *
2560 * @param string $s
2561 * @return string
2562 */
2563 public function addIdentifierQuotes( $s ) {
2564 return '"' . str_replace( '"', '""', $s ) . '"';
2565 }
2566
2567 /**
2568 * Returns if the given identifier looks quoted or not according to
2569 * the database convention for quoting identifiers .
2570 *
2571 * @note Do not use this to determine if untrusted input is safe.
2572 * A malicious user can trick this function.
2573 * @param string $name
2574 * @return bool
2575 */
2576 public function isQuotedIdentifier( $name ) {
2577 return $name[0] == '"' && substr( $name, -1, 1 ) == '"';
2578 }
2579
2580 /**
2581 * @param string $s
2582 * @param string $escapeChar
2583 * @return string
2584 */
2585 protected function escapeLikeInternal( $s, $escapeChar = '`' ) {
2586 return str_replace( [ $escapeChar, '%', '_' ],
2587 [ "{$escapeChar}{$escapeChar}", "{$escapeChar}%", "{$escapeChar}_" ],
2588 $s );
2589 }
2590
2591 public function buildLike() {
2592 $params = func_get_args();
2593
2594 if ( count( $params ) > 0 && is_array( $params[0] ) ) {
2595 $params = $params[0];
2596 }
2597
2598 $s = '';
2599
2600 // We use ` instead of \ as the default LIKE escape character, since addQuotes()
2601 // may escape backslashes, creating problems of double escaping. The `
2602 // character has good cross-DBMS compatibility, avoiding special operators
2603 // in MS SQL like ^ and %
2604 $escapeChar = '`';
2605
2606 foreach ( $params as $value ) {
2607 if ( $value instanceof LikeMatch ) {
2608 $s .= $value->toString();
2609 } else {
2610 $s .= $this->escapeLikeInternal( $value, $escapeChar );
2611 }
2612 }
2613
2614 return ' LIKE ' .
2615 $this->addQuotes( $s ) . ' ESCAPE ' . $this->addQuotes( $escapeChar ) . ' ';
2616 }
2617
2618 public function anyChar() {
2619 return new LikeMatch( '_' );
2620 }
2621
2622 public function anyString() {
2623 return new LikeMatch( '%' );
2624 }
2625
2626 public function nextSequenceValue( $seqName ) {
2627 return null;
2628 }
2629
2630 /**
2631 * USE INDEX clause. Unlikely to be useful for anything but MySQL. This
2632 * is only needed because a) MySQL must be as efficient as possible due to
2633 * its use on Wikipedia, and b) MySQL 4.0 is kind of dumb sometimes about
2634 * which index to pick. Anyway, other databases might have different
2635 * indexes on a given table. So don't bother overriding this unless you're
2636 * MySQL.
2637 * @param string $index
2638 * @return string
2639 */
2640 public function useIndexClause( $index ) {
2641 return '';
2642 }
2643
2644 /**
2645 * IGNORE INDEX clause. Unlikely to be useful for anything but MySQL. This
2646 * is only needed because a) MySQL must be as efficient as possible due to
2647 * its use on Wikipedia, and b) MySQL 4.0 is kind of dumb sometimes about
2648 * which index to pick. Anyway, other databases might have different
2649 * indexes on a given table. So don't bother overriding this unless you're
2650 * MySQL.
2651 * @param string $index
2652 * @return string
2653 */
2654 public function ignoreIndexClause( $index ) {
2655 return '';
2656 }
2657
2658 public function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__ ) {
2659 if ( count( $rows ) == 0 ) {
2660 return;
2661 }
2662
2663 // Single row case
2664 if ( !is_array( reset( $rows ) ) ) {
2665 $rows = [ $rows ];
2666 }
2667
2668 try {
2669 $this->startAtomic( $fname, self::ATOMIC_CANCELABLE );
2670 $affectedRowCount = 0;
2671 foreach ( $rows as $row ) {
2672 // Delete rows which collide with this one
2673 $indexWhereClauses = [];
2674 foreach ( $uniqueIndexes as $index ) {
2675 $indexColumns = (array)$index;
2676 $indexRowValues = array_intersect_key( $row, array_flip( $indexColumns ) );
2677 if ( count( $indexRowValues ) != count( $indexColumns ) ) {
2678 throw new DBUnexpectedError(
2679 $this,
2680 'New record does not provide all values for unique key (' .
2681 implode( ', ', $indexColumns ) . ')'
2682 );
2683 } elseif ( in_array( null, $indexRowValues, true ) ) {
2684 throw new DBUnexpectedError(
2685 $this,
2686 'New record has a null value for unique key (' .
2687 implode( ', ', $indexColumns ) . ')'
2688 );
2689 }
2690 $indexWhereClauses[] = $this->makeList( $indexRowValues, LIST_AND );
2691 }
2692
2693 if ( $indexWhereClauses ) {
2694 $this->delete( $table, $this->makeList( $indexWhereClauses, LIST_OR ), $fname );
2695 $affectedRowCount += $this->affectedRows();
2696 }
2697
2698 // Now insert the row
2699 $this->insert( $table, $row, $fname );
2700 $affectedRowCount += $this->affectedRows();
2701 }
2702 $this->endAtomic( $fname );
2703 $this->affectedRowCount = $affectedRowCount;
2704 } catch ( Exception $e ) {
2705 $this->cancelAtomic( $fname );
2706 throw $e;
2707 }
2708 }
2709
2710 /**
2711 * REPLACE query wrapper for MySQL and SQLite, which have a native REPLACE
2712 * statement.
2713 *
2714 * @param string $table Table name
2715 * @param array|string $rows Row(s) to insert
2716 * @param string $fname Caller function name
2717 *
2718 * @return ResultWrapper
2719 */
2720 protected function nativeReplace( $table, $rows, $fname ) {
2721 $table = $this->tableName( $table );
2722
2723 # Single row case
2724 if ( !is_array( reset( $rows ) ) ) {
2725 $rows = [ $rows ];
2726 }
2727
2728 $sql = "REPLACE INTO $table (" . implode( ',', array_keys( $rows[0] ) ) . ') VALUES ';
2729 $first = true;
2730
2731 foreach ( $rows as $row ) {
2732 if ( $first ) {
2733 $first = false;
2734 } else {
2735 $sql .= ',';
2736 }
2737
2738 $sql .= '(' . $this->makeList( $row ) . ')';
2739 }
2740
2741 return $this->query( $sql, $fname );
2742 }
2743
2744 public function upsert( $table, array $rows, array $uniqueIndexes, array $set,
2745 $fname = __METHOD__
2746 ) {
2747 if ( !count( $rows ) ) {
2748 return true; // nothing to do
2749 }
2750
2751 if ( !is_array( reset( $rows ) ) ) {
2752 $rows = [ $rows ];
2753 }
2754
2755 if ( count( $uniqueIndexes ) ) {
2756 $clauses = []; // list WHERE clauses that each identify a single row
2757 foreach ( $rows as $row ) {
2758 foreach ( $uniqueIndexes as $index ) {
2759 $index = is_array( $index ) ? $index : [ $index ]; // columns
2760 $rowKey = []; // unique key to this row
2761 foreach ( $index as $column ) {
2762 $rowKey[$column] = $row[$column];
2763 }
2764 $clauses[] = $this->makeList( $rowKey, self::LIST_AND );
2765 }
2766 }
2767 $where = [ $this->makeList( $clauses, self::LIST_OR ) ];
2768 } else {
2769 $where = false;
2770 }
2771
2772 $affectedRowCount = 0;
2773 try {
2774 $this->startAtomic( $fname, self::ATOMIC_CANCELABLE );
2775 # Update any existing conflicting row(s)
2776 if ( $where !== false ) {
2777 $ok = $this->update( $table, $set, $where, $fname );
2778 $affectedRowCount += $this->affectedRows();
2779 } else {
2780 $ok = true;
2781 }
2782 # Now insert any non-conflicting row(s)
2783 $ok = $this->insert( $table, $rows, $fname, [ 'IGNORE' ] ) && $ok;
2784 $affectedRowCount += $this->affectedRows();
2785 $this->endAtomic( $fname );
2786 $this->affectedRowCount = $affectedRowCount;
2787 } catch ( Exception $e ) {
2788 $this->cancelAtomic( $fname );
2789 throw $e;
2790 }
2791
2792 return $ok;
2793 }
2794
2795 public function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds,
2796 $fname = __METHOD__
2797 ) {
2798 if ( !$conds ) {
2799 throw new DBUnexpectedError( $this, __METHOD__ . ' called with empty $conds' );
2800 }
2801
2802 $delTable = $this->tableName( $delTable );
2803 $joinTable = $this->tableName( $joinTable );
2804 $sql = "DELETE FROM $delTable WHERE $delVar IN (SELECT $joinVar FROM $joinTable ";
2805 if ( $conds != '*' ) {
2806 $sql .= 'WHERE ' . $this->makeList( $conds, self::LIST_AND );
2807 }
2808 $sql .= ')';
2809
2810 $this->query( $sql, $fname );
2811 }
2812
2813 public function textFieldSize( $table, $field ) {
2814 $table = $this->tableName( $table );
2815 $sql = "SHOW COLUMNS FROM $table LIKE \"$field\";";
2816 $res = $this->query( $sql, __METHOD__ );
2817 $row = $this->fetchObject( $res );
2818
2819 $m = [];
2820
2821 if ( preg_match( '/\((.*)\)/', $row->Type, $m ) ) {
2822 $size = $m[1];
2823 } else {
2824 $size = -1;
2825 }
2826
2827 return $size;
2828 }
2829
2830 public function delete( $table, $conds, $fname = __METHOD__ ) {
2831 if ( !$conds ) {
2832 throw new DBUnexpectedError( $this, __METHOD__ . ' called with no conditions' );
2833 }
2834
2835 $table = $this->tableName( $table );
2836 $sql = "DELETE FROM $table";
2837
2838 if ( $conds != '*' ) {
2839 if ( is_array( $conds ) ) {
2840 $conds = $this->makeList( $conds, self::LIST_AND );
2841 }
2842 $sql .= ' WHERE ' . $conds;
2843 }
2844
2845 return $this->query( $sql, $fname );
2846 }
2847
2848 final public function insertSelect(
2849 $destTable, $srcTable, $varMap, $conds,
2850 $fname = __METHOD__, $insertOptions = [], $selectOptions = [], $selectJoinConds = []
2851 ) {
2852 static $hints = [ 'NO_AUTO_COLUMNS' ];
2853
2854 $insertOptions = (array)$insertOptions;
2855 $selectOptions = (array)$selectOptions;
2856
2857 if ( $this->cliMode && $this->isInsertSelectSafe( $insertOptions, $selectOptions ) ) {
2858 // For massive migrations with downtime, we don't want to select everything
2859 // into memory and OOM, so do all this native on the server side if possible.
2860 return $this->nativeInsertSelect(
2861 $destTable,
2862 $srcTable,
2863 $varMap,
2864 $conds,
2865 $fname,
2866 array_diff( $insertOptions, $hints ),
2867 $selectOptions,
2868 $selectJoinConds
2869 );
2870 }
2871
2872 return $this->nonNativeInsertSelect(
2873 $destTable,
2874 $srcTable,
2875 $varMap,
2876 $conds,
2877 $fname,
2878 array_diff( $insertOptions, $hints ),
2879 $selectOptions,
2880 $selectJoinConds
2881 );
2882 }
2883
2884 /**
2885 * @param array $insertOptions INSERT options
2886 * @param array $selectOptions SELECT options
2887 * @return bool Whether an INSERT SELECT with these options will be replication safe
2888 * @since 1.31
2889 */
2890 protected function isInsertSelectSafe( array $insertOptions, array $selectOptions ) {
2891 return true;
2892 }
2893
2894 /**
2895 * Implementation of insertSelect() based on select() and insert()
2896 *
2897 * @see IDatabase::insertSelect()
2898 * @since 1.30
2899 * @param string $destTable
2900 * @param string|array $srcTable
2901 * @param array $varMap
2902 * @param array $conds
2903 * @param string $fname
2904 * @param array $insertOptions
2905 * @param array $selectOptions
2906 * @param array $selectJoinConds
2907 * @return bool
2908 */
2909 protected function nonNativeInsertSelect( $destTable, $srcTable, $varMap, $conds,
2910 $fname = __METHOD__,
2911 $insertOptions = [], $selectOptions = [], $selectJoinConds = []
2912 ) {
2913 // For web requests, do a locking SELECT and then INSERT. This puts the SELECT burden
2914 // on only the master (without needing row-based-replication). It also makes it easy to
2915 // know how big the INSERT is going to be.
2916 $fields = [];
2917 foreach ( $varMap as $dstColumn => $sourceColumnOrSql ) {
2918 $fields[] = $this->fieldNameWithAlias( $sourceColumnOrSql, $dstColumn );
2919 }
2920 $selectOptions[] = 'FOR UPDATE';
2921 $res = $this->select(
2922 $srcTable, implode( ',', $fields ), $conds, $fname, $selectOptions, $selectJoinConds
2923 );
2924 if ( !$res ) {
2925 return false;
2926 }
2927
2928 try {
2929 $affectedRowCount = 0;
2930 $this->startAtomic( $fname, self::ATOMIC_CANCELABLE );
2931 $rows = [];
2932 $ok = true;
2933 foreach ( $res as $row ) {
2934 $rows[] = (array)$row;
2935
2936 // Avoid inserts that are too huge
2937 if ( count( $rows ) >= $this->nonNativeInsertSelectBatchSize ) {
2938 $ok = $this->insert( $destTable, $rows, $fname, $insertOptions );
2939 if ( !$ok ) {
2940 break;
2941 }
2942 $affectedRowCount += $this->affectedRows();
2943 $rows = [];
2944 }
2945 }
2946 if ( $rows && $ok ) {
2947 $ok = $this->insert( $destTable, $rows, $fname, $insertOptions );
2948 if ( $ok ) {
2949 $affectedRowCount += $this->affectedRows();
2950 }
2951 }
2952 if ( $ok ) {
2953 $this->endAtomic( $fname );
2954 $this->affectedRowCount = $affectedRowCount;
2955 } else {
2956 $this->cancelAtomic( $fname );
2957 }
2958 return $ok;
2959 } catch ( Exception $e ) {
2960 $this->cancelAtomic( $fname );
2961 throw $e;
2962 }
2963 }
2964
2965 /**
2966 * Native server-side implementation of insertSelect() for situations where
2967 * we don't want to select everything into memory
2968 *
2969 * @see IDatabase::insertSelect()
2970 * @param string $destTable
2971 * @param string|array $srcTable
2972 * @param array $varMap
2973 * @param array $conds
2974 * @param string $fname
2975 * @param array $insertOptions
2976 * @param array $selectOptions
2977 * @param array $selectJoinConds
2978 * @return bool
2979 */
2980 protected function nativeInsertSelect( $destTable, $srcTable, $varMap, $conds,
2981 $fname = __METHOD__,
2982 $insertOptions = [], $selectOptions = [], $selectJoinConds = []
2983 ) {
2984 $destTable = $this->tableName( $destTable );
2985
2986 if ( !is_array( $insertOptions ) ) {
2987 $insertOptions = [ $insertOptions ];
2988 }
2989
2990 $insertOptions = $this->makeInsertOptions( $insertOptions );
2991
2992 $selectSql = $this->selectSQLText(
2993 $srcTable,
2994 array_values( $varMap ),
2995 $conds,
2996 $fname,
2997 $selectOptions,
2998 $selectJoinConds
2999 );
3000
3001 $sql = "INSERT $insertOptions" .
3002 " INTO $destTable (" . implode( ',', array_keys( $varMap ) ) . ') ' .
3003 $selectSql;
3004
3005 return $this->query( $sql, $fname );
3006 }
3007
3008 /**
3009 * Construct a LIMIT query with optional offset. This is used for query
3010 * pages. The SQL should be adjusted so that only the first $limit rows
3011 * are returned. If $offset is provided as well, then the first $offset
3012 * rows should be discarded, and the next $limit rows should be returned.
3013 * If the result of the query is not ordered, then the rows to be returned
3014 * are theoretically arbitrary.
3015 *
3016 * $sql is expected to be a SELECT, if that makes a difference.
3017 *
3018 * The version provided by default works in MySQL and SQLite. It will very
3019 * likely need to be overridden for most other DBMSes.
3020 *
3021 * @param string $sql SQL query we will append the limit too
3022 * @param int $limit The SQL limit
3023 * @param int|bool $offset The SQL offset (default false)
3024 * @throws DBUnexpectedError
3025 * @return string
3026 */
3027 public function limitResult( $sql, $limit, $offset = false ) {
3028 if ( !is_numeric( $limit ) ) {
3029 throw new DBUnexpectedError( $this,
3030 "Invalid non-numeric limit passed to limitResult()\n" );
3031 }
3032
3033 return "$sql LIMIT "
3034 . ( ( is_numeric( $offset ) && $offset != 0 ) ? "{$offset}," : "" )
3035 . "{$limit} ";
3036 }
3037
3038 public function unionSupportsOrderAndLimit() {
3039 return true; // True for almost every DB supported
3040 }
3041
3042 public function unionQueries( $sqls, $all ) {
3043 $glue = $all ? ') UNION ALL (' : ') UNION (';
3044
3045 return '(' . implode( $glue, $sqls ) . ')';
3046 }
3047
3048 public function unionConditionPermutations(
3049 $table, $vars, array $permute_conds, $extra_conds = '', $fname = __METHOD__,
3050 $options = [], $join_conds = []
3051 ) {
3052 // First, build the Cartesian product of $permute_conds
3053 $conds = [ [] ];
3054 foreach ( $permute_conds as $field => $values ) {
3055 if ( !$values ) {
3056 // Skip empty $values
3057 continue;
3058 }
3059 $values = array_unique( $values ); // For sanity
3060 $newConds = [];
3061 foreach ( $conds as $cond ) {
3062 foreach ( $values as $value ) {
3063 $cond[$field] = $value;
3064 $newConds[] = $cond; // Arrays are by-value, not by-reference, so this works
3065 }
3066 }
3067 $conds = $newConds;
3068 }
3069
3070 $extra_conds = $extra_conds === '' ? [] : (array)$extra_conds;
3071
3072 // If there's just one condition and no subordering, hand off to
3073 // selectSQLText directly.
3074 if ( count( $conds ) === 1 &&
3075 ( !isset( $options['INNER ORDER BY'] ) || !$this->unionSupportsOrderAndLimit() )
3076 ) {
3077 return $this->selectSQLText(
3078 $table, $vars, $conds[0] + $extra_conds, $fname, $options, $join_conds
3079 );
3080 }
3081
3082 // Otherwise, we need to pull out the order and limit to apply after
3083 // the union. Then build the SQL queries for each set of conditions in
3084 // $conds. Then union them together (using UNION ALL, because the
3085 // product *should* already be distinct).
3086 $orderBy = $this->makeOrderBy( $options );
3087 $limit = isset( $options['LIMIT'] ) ? $options['LIMIT'] : null;
3088 $offset = isset( $options['OFFSET'] ) ? $options['OFFSET'] : false;
3089 $all = empty( $options['NOTALL'] ) && !in_array( 'NOTALL', $options );
3090 if ( !$this->unionSupportsOrderAndLimit() ) {
3091 unset( $options['ORDER BY'], $options['LIMIT'], $options['OFFSET'] );
3092 } else {
3093 if ( array_key_exists( 'INNER ORDER BY', $options ) ) {
3094 $options['ORDER BY'] = $options['INNER ORDER BY'];
3095 }
3096 if ( $limit !== null && is_numeric( $offset ) && $offset != 0 ) {
3097 // We need to increase the limit by the offset rather than
3098 // using the offset directly, otherwise it'll skip incorrectly
3099 // in the subqueries.
3100 $options['LIMIT'] = $limit + $offset;
3101 unset( $options['OFFSET'] );
3102 }
3103 }
3104
3105 $sqls = [];
3106 foreach ( $conds as $cond ) {
3107 $sqls[] = $this->selectSQLText(
3108 $table, $vars, $cond + $extra_conds, $fname, $options, $join_conds
3109 );
3110 }
3111 $sql = $this->unionQueries( $sqls, $all ) . $orderBy;
3112 if ( $limit !== null ) {
3113 $sql = $this->limitResult( $sql, $limit, $offset );
3114 }
3115
3116 return $sql;
3117 }
3118
3119 public function conditional( $cond, $trueVal, $falseVal ) {
3120 if ( is_array( $cond ) ) {
3121 $cond = $this->makeList( $cond, self::LIST_AND );
3122 }
3123
3124 return " (CASE WHEN $cond THEN $trueVal ELSE $falseVal END) ";
3125 }
3126
3127 public function strreplace( $orig, $old, $new ) {
3128 return "REPLACE({$orig}, {$old}, {$new})";
3129 }
3130
3131 public function getServerUptime() {
3132 return 0;
3133 }
3134
3135 public function wasDeadlock() {
3136 return false;
3137 }
3138
3139 public function wasLockTimeout() {
3140 return false;
3141 }
3142
3143 public function wasConnectionLoss() {
3144 return $this->wasConnectionError( $this->lastErrno() );
3145 }
3146
3147 public function wasReadOnlyError() {
3148 return false;
3149 }
3150
3151 public function wasErrorReissuable() {
3152 return (
3153 $this->wasDeadlock() ||
3154 $this->wasLockTimeout() ||
3155 $this->wasConnectionLoss()
3156 );
3157 }
3158
3159 /**
3160 * Do not use this method outside of Database/DBError classes
3161 *
3162 * @param int|string $errno
3163 * @return bool Whether the given query error was a connection drop
3164 */
3165 public function wasConnectionError( $errno ) {
3166 return false;
3167 }
3168
3169 /**
3170 * @return bool Whether it is safe to assume the given error only caused statement rollback
3171 * @note This is for backwards compatibility for callers catching DBError exceptions in
3172 * order to ignore problems like duplicate key errors or foriegn key violations
3173 * @since 1.31
3174 */
3175 protected function wasKnownStatementRollbackError() {
3176 return false; // don't know; it could have caused a transaction rollback
3177 }
3178
3179 public function deadlockLoop() {
3180 $args = func_get_args();
3181 $function = array_shift( $args );
3182 $tries = self::DEADLOCK_TRIES;
3183
3184 $this->begin( __METHOD__ );
3185
3186 $retVal = null;
3187 /** @var Exception $e */
3188 $e = null;
3189 do {
3190 try {
3191 $retVal = call_user_func_array( $function, $args );
3192 break;
3193 } catch ( DBQueryError $e ) {
3194 if ( $this->wasDeadlock() ) {
3195 // Retry after a randomized delay
3196 usleep( mt_rand( self::DEADLOCK_DELAY_MIN, self::DEADLOCK_DELAY_MAX ) );
3197 } else {
3198 // Throw the error back up
3199 throw $e;
3200 }
3201 }
3202 } while ( --$tries > 0 );
3203
3204 if ( $tries <= 0 ) {
3205 // Too many deadlocks; give up
3206 $this->rollback( __METHOD__ );
3207 throw $e;
3208 } else {
3209 $this->commit( __METHOD__ );
3210
3211 return $retVal;
3212 }
3213 }
3214
3215 public function masterPosWait( DBMasterPos $pos, $timeout ) {
3216 # Real waits are implemented in the subclass.
3217 return 0;
3218 }
3219
3220 public function getReplicaPos() {
3221 # Stub
3222 return false;
3223 }
3224
3225 public function getMasterPos() {
3226 # Stub
3227 return false;
3228 }
3229
3230 public function serverIsReadOnly() {
3231 return false;
3232 }
3233
3234 final public function onTransactionResolution( callable $callback, $fname = __METHOD__ ) {
3235 if ( !$this->trxLevel ) {
3236 throw new DBUnexpectedError( $this, "No transaction is active." );
3237 }
3238 $this->trxEndCallbacks[] = [ $callback, $fname, $this->currentAtomicSectionId() ];
3239 }
3240
3241 final public function onTransactionIdle( callable $callback, $fname = __METHOD__ ) {
3242 if ( !$this->trxLevel && $this->getTransactionRoundId() ) {
3243 // Start an implicit transaction similar to how query() does
3244 $this->begin( __METHOD__, self::TRANSACTION_INTERNAL );
3245 $this->trxAutomatic = true;
3246 }
3247
3248 $this->trxIdleCallbacks[] = [ $callback, $fname, $this->currentAtomicSectionId() ];
3249 if ( !$this->trxLevel ) {
3250 $this->runOnTransactionIdleCallbacks( self::TRIGGER_IDLE );
3251 }
3252 }
3253
3254 final public function onTransactionPreCommitOrIdle( callable $callback, $fname = __METHOD__ ) {
3255 if ( !$this->trxLevel && $this->getTransactionRoundId() ) {
3256 // Start an implicit transaction similar to how query() does
3257 $this->begin( __METHOD__, self::TRANSACTION_INTERNAL );
3258 $this->trxAutomatic = true;
3259 }
3260
3261 if ( $this->trxLevel ) {
3262 $this->trxPreCommitCallbacks[] = [ $callback, $fname, $this->currentAtomicSectionId() ];
3263 } else {
3264 // No transaction is active nor will start implicitly, so make one for this callback
3265 $this->startAtomic( __METHOD__, self::ATOMIC_CANCELABLE );
3266 try {
3267 call_user_func( $callback );
3268 $this->endAtomic( __METHOD__ );
3269 } catch ( Exception $e ) {
3270 $this->cancelAtomic( __METHOD__ );
3271 throw $e;
3272 }
3273 }
3274 }
3275
3276 /**
3277 * @return AtomicSectionIdentifier|null ID of the topmost atomic section level
3278 */
3279 private function currentAtomicSectionId() {
3280 if ( $this->trxLevel && $this->trxAtomicLevels ) {
3281 $levelInfo = end( $this->trxAtomicLevels );
3282
3283 return $levelInfo[1];
3284 }
3285
3286 return null;
3287 }
3288
3289 /**
3290 * @param AtomicSectionIdentifier $old
3291 * @param AtomicSectionIdentifier $new
3292 */
3293 private function reassignCallbacksForSection(
3294 AtomicSectionIdentifier $old, AtomicSectionIdentifier $new
3295 ) {
3296 foreach ( $this->trxPreCommitCallbacks as $key => $info ) {
3297 if ( $info[2] === $old ) {
3298 $this->trxPreCommitCallbacks[$key][2] = $new;
3299 }
3300 }
3301 foreach ( $this->trxIdleCallbacks as $key => $info ) {
3302 if ( $info[2] === $old ) {
3303 $this->trxIdleCallbacks[$key][2] = $new;
3304 }
3305 }
3306 foreach ( $this->trxEndCallbacks as $key => $info ) {
3307 if ( $info[2] === $old ) {
3308 $this->trxEndCallbacks[$key][2] = $new;
3309 }
3310 }
3311 }
3312
3313 /**
3314 * @param AtomicSectionIdentifier[] $sectionIds ID of an actual savepoint
3315 * @throws UnexpectedValueException
3316 */
3317 private function modifyCallbacksForCancel( array $sectionIds ) {
3318 // Cancel the "on commit" callbacks owned by this savepoint
3319 $this->trxIdleCallbacks = array_filter(
3320 $this->trxIdleCallbacks,
3321 function ( $entry ) use ( $sectionIds ) {
3322 return !in_array( $entry[2], $sectionIds, true );
3323 }
3324 );
3325 $this->trxPreCommitCallbacks = array_filter(
3326 $this->trxPreCommitCallbacks,
3327 function ( $entry ) use ( $sectionIds ) {
3328 return !in_array( $entry[2], $sectionIds, true );
3329 }
3330 );
3331 // Make "on resolution" callbacks owned by this savepoint to perceive a rollback
3332 foreach ( $this->trxEndCallbacks as $key => $entry ) {
3333 if ( in_array( $entry[2], $sectionIds, true ) ) {
3334 $callback = $entry[0];
3335 $this->trxEndCallbacks[$key][0] = function () use ( $callback ) {
3336 return $callback( self::TRIGGER_ROLLBACK );
3337 };
3338 }
3339 }
3340 }
3341
3342 final public function setTransactionListener( $name, callable $callback = null ) {
3343 if ( $callback ) {
3344 $this->trxRecurringCallbacks[$name] = $callback;
3345 } else {
3346 unset( $this->trxRecurringCallbacks[$name] );
3347 }
3348 }
3349
3350 /**
3351 * Whether to disable running of post-COMMIT/ROLLBACK callbacks
3352 *
3353 * This method should not be used outside of Database/LoadBalancer
3354 *
3355 * @param bool $suppress
3356 * @since 1.28
3357 */
3358 final public function setTrxEndCallbackSuppression( $suppress ) {
3359 $this->trxEndCallbacksSuppressed = $suppress;
3360 }
3361
3362 /**
3363 * Actually run and consume any "on transaction idle/resolution" callbacks.
3364 *
3365 * This method should not be used outside of Database/LoadBalancer
3366 *
3367 * @param int $trigger IDatabase::TRIGGER_* constant
3368 * @since 1.20
3369 * @throws Exception
3370 */
3371 public function runOnTransactionIdleCallbacks( $trigger ) {
3372 if ( $this->trxEndCallbacksSuppressed ) {
3373 return;
3374 }
3375
3376 $autoTrx = $this->getFlag( self::DBO_TRX ); // automatic begin() enabled?
3377 /** @var Exception $e */
3378 $e = null; // first exception
3379 do { // callbacks may add callbacks :)
3380 $callbacks = array_merge(
3381 $this->trxIdleCallbacks,
3382 $this->trxEndCallbacks // include "transaction resolution" callbacks
3383 );
3384 $this->trxIdleCallbacks = []; // consumed (and recursion guard)
3385 $this->trxEndCallbacks = []; // consumed (recursion guard)
3386 foreach ( $callbacks as $callback ) {
3387 try {
3388 list( $phpCallback ) = $callback;
3389 $this->clearFlag( self::DBO_TRX ); // make each query its own transaction
3390 call_user_func_array( $phpCallback, [ $trigger ] );
3391 if ( $autoTrx ) {
3392 $this->setFlag( self::DBO_TRX ); // restore automatic begin()
3393 } else {
3394 $this->clearFlag( self::DBO_TRX ); // restore auto-commit
3395 }
3396 } catch ( Exception $ex ) {
3397 call_user_func( $this->errorLogger, $ex );
3398 $e = $e ?: $ex;
3399 // Some callbacks may use startAtomic/endAtomic, so make sure
3400 // their transactions are ended so other callbacks don't fail
3401 if ( $this->trxLevel() ) {
3402 $this->rollback( __METHOD__, self::FLUSHING_INTERNAL );
3403 }
3404 }
3405 }
3406 } while ( count( $this->trxIdleCallbacks ) );
3407
3408 if ( $e instanceof Exception ) {
3409 throw $e; // re-throw any first exception
3410 }
3411 }
3412
3413 /**
3414 * Actually run and consume any "on transaction pre-commit" callbacks.
3415 *
3416 * This method should not be used outside of Database/LoadBalancer
3417 *
3418 * @since 1.22
3419 * @throws Exception
3420 */
3421 public function runOnTransactionPreCommitCallbacks() {
3422 $e = null; // first exception
3423 do { // callbacks may add callbacks :)
3424 $callbacks = $this->trxPreCommitCallbacks;
3425 $this->trxPreCommitCallbacks = []; // consumed (and recursion guard)
3426 foreach ( $callbacks as $callback ) {
3427 try {
3428 list( $phpCallback ) = $callback;
3429 call_user_func( $phpCallback );
3430 } catch ( Exception $ex ) {
3431 call_user_func( $this->errorLogger, $ex );
3432 $e = $e ?: $ex;
3433 }
3434 }
3435 } while ( count( $this->trxPreCommitCallbacks ) );
3436
3437 if ( $e instanceof Exception ) {
3438 throw $e; // re-throw any first exception
3439 }
3440 }
3441
3442 /**
3443 * Actually run any "transaction listener" callbacks.
3444 *
3445 * This method should not be used outside of Database/LoadBalancer
3446 *
3447 * @param int $trigger IDatabase::TRIGGER_* constant
3448 * @throws Exception
3449 * @since 1.20
3450 */
3451 public function runTransactionListenerCallbacks( $trigger ) {
3452 if ( $this->trxEndCallbacksSuppressed ) {
3453 return;
3454 }
3455
3456 /** @var Exception $e */
3457 $e = null; // first exception
3458
3459 foreach ( $this->trxRecurringCallbacks as $phpCallback ) {
3460 try {
3461 $phpCallback( $trigger, $this );
3462 } catch ( Exception $ex ) {
3463 call_user_func( $this->errorLogger, $ex );
3464 $e = $e ?: $ex;
3465 }
3466 }
3467
3468 if ( $e instanceof Exception ) {
3469 throw $e; // re-throw any first exception
3470 }
3471 }
3472
3473 /**
3474 * Create a savepoint
3475 *
3476 * This is used internally to implement atomic sections. It should not be
3477 * used otherwise.
3478 *
3479 * @since 1.31
3480 * @param string $identifier Identifier for the savepoint
3481 * @param string $fname Calling function name
3482 */
3483 protected function doSavepoint( $identifier, $fname ) {
3484 $this->query( 'SAVEPOINT ' . $this->addIdentifierQuotes( $identifier ), $fname );
3485 }
3486
3487 /**
3488 * Release a savepoint
3489 *
3490 * This is used internally to implement atomic sections. It should not be
3491 * used otherwise.
3492 *
3493 * @since 1.31
3494 * @param string $identifier Identifier for the savepoint
3495 * @param string $fname Calling function name
3496 */
3497 protected function doReleaseSavepoint( $identifier, $fname ) {
3498 $this->query( 'RELEASE SAVEPOINT ' . $this->addIdentifierQuotes( $identifier ), $fname );
3499 }
3500
3501 /**
3502 * Rollback to a savepoint
3503 *
3504 * This is used internally to implement atomic sections. It should not be
3505 * used otherwise.
3506 *
3507 * @since 1.31
3508 * @param string $identifier Identifier for the savepoint
3509 * @param string $fname Calling function name
3510 */
3511 protected function doRollbackToSavepoint( $identifier, $fname ) {
3512 $this->query( 'ROLLBACK TO SAVEPOINT ' . $this->addIdentifierQuotes( $identifier ), $fname );
3513 }
3514
3515 /**
3516 * @param string $fname
3517 * @return string
3518 */
3519 private function nextSavepointId( $fname ) {
3520 $savepointId = self::$SAVEPOINT_PREFIX . ++$this->trxAtomicCounter;
3521 if ( strlen( $savepointId ) > 30 ) {
3522 // 30 == Oracle's identifier length limit (pre 12c)
3523 // With a 22 character prefix, that puts the highest number at 99999999.
3524 throw new DBUnexpectedError(
3525 $this,
3526 'There have been an excessively large number of atomic sections in a transaction'
3527 . " started by $this->trxFname (at $fname)"
3528 );
3529 }
3530
3531 return $savepointId;
3532 }
3533
3534 final public function startAtomic(
3535 $fname = __METHOD__, $cancelable = self::ATOMIC_NOT_CANCELABLE
3536 ) {
3537 $savepointId = $cancelable === self::ATOMIC_CANCELABLE ? self::$NOT_APPLICABLE : null;
3538
3539 if ( !$this->trxLevel ) {
3540 $this->begin( $fname, self::TRANSACTION_INTERNAL );
3541 // If DBO_TRX is set, a series of startAtomic/endAtomic pairs will result
3542 // in all changes being in one transaction to keep requests transactional.
3543 if ( $this->getFlag( self::DBO_TRX ) ) {
3544 // Since writes could happen in between the topmost atomic sections as part
3545 // of the transaction, those sections will need savepoints.
3546 $savepointId = $this->nextSavepointId( $fname );
3547 $this->doSavepoint( $savepointId, $fname );
3548 } else {
3549 $this->trxAutomaticAtomic = true;
3550 }
3551 } elseif ( $cancelable === self::ATOMIC_CANCELABLE ) {
3552 $savepointId = $this->nextSavepointId( $fname );
3553 $this->doSavepoint( $savepointId, $fname );
3554 }
3555
3556 $sectionId = new AtomicSectionIdentifier;
3557 $this->trxAtomicLevels[] = [ $fname, $sectionId, $savepointId ];
3558
3559 return $sectionId;
3560 }
3561
3562 final public function endAtomic( $fname = __METHOD__ ) {
3563 if ( !$this->trxLevel || !$this->trxAtomicLevels ) {
3564 throw new DBUnexpectedError( $this, "No atomic section is open (got $fname)." );
3565 }
3566
3567 // Check if the current section matches $fname
3568 $pos = count( $this->trxAtomicLevels ) - 1;
3569 list( $savedFname, $sectionId, $savepointId ) = $this->trxAtomicLevels[$pos];
3570
3571 if ( $savedFname !== $fname ) {
3572 throw new DBUnexpectedError(
3573 $this,
3574 "Invalid atomic section ended (got $fname but expected $savedFname)."
3575 );
3576 }
3577
3578 // Remove the last section (no need to re-index the array)
3579 array_pop( $this->trxAtomicLevels );
3580
3581 if ( !$this->trxAtomicLevels && $this->trxAutomaticAtomic ) {
3582 $this->commit( $fname, self::FLUSHING_INTERNAL );
3583 } elseif ( $savepointId !== null && $savepointId !== self::$NOT_APPLICABLE ) {
3584 $this->doReleaseSavepoint( $savepointId, $fname );
3585 }
3586
3587 // Hoist callback ownership for callbacks in the section that just ended;
3588 // all callbacks should have an owner that is present in trxAtomicLevels.
3589 $currentSectionId = $this->currentAtomicSectionId();
3590 if ( $currentSectionId ) {
3591 $this->reassignCallbacksForSection( $sectionId, $currentSectionId );
3592 }
3593 }
3594
3595 final public function cancelAtomic(
3596 $fname = __METHOD__, AtomicSectionIdentifier $sectionId = null
3597 ) {
3598 if ( !$this->trxLevel || !$this->trxAtomicLevels ) {
3599 throw new DBUnexpectedError( $this, "No atomic section is open (got $fname)." );
3600 }
3601
3602 if ( $sectionId !== null ) {
3603 // Find the (last) section with the given $sectionId
3604 $pos = -1;
3605 foreach ( $this->trxAtomicLevels as $i => list( $asFname, $asId, $spId ) ) {
3606 if ( $asId === $sectionId ) {
3607 $pos = $i;
3608 }
3609 }
3610 if ( $pos < 0 ) {
3611 throw new DBUnexpectedError( "Atomic section not found (for $fname)" );
3612 }
3613 // Remove all descendant sections and re-index the array
3614 $excisedIds = [];
3615 $len = count( $this->trxAtomicLevels );
3616 for ( $i = $pos + 1; $i < $len; ++$i ) {
3617 $excisedIds[] = $this->trxAtomicLevels[$i][1];
3618 }
3619 $this->trxAtomicLevels = array_slice( $this->trxAtomicLevels, 0, $pos + 1 );
3620 $this->modifyCallbacksForCancel( $excisedIds );
3621 }
3622
3623 // Check if the current section matches $fname
3624 $pos = count( $this->trxAtomicLevels ) - 1;
3625 list( $savedFname, $savedSectionId, $savepointId ) = $this->trxAtomicLevels[$pos];
3626
3627 if ( $savedFname !== $fname ) {
3628 throw new DBUnexpectedError(
3629 $this,
3630 "Invalid atomic section ended (got $fname but expected $savedFname)."
3631 );
3632 }
3633
3634 // Remove the last section (no need to re-index the array)
3635 array_pop( $this->trxAtomicLevels );
3636 $this->modifyCallbacksForCancel( [ $savedSectionId ] );
3637
3638 if ( $savepointId !== null ) {
3639 // Rollback the transaction to the state just before this atomic section
3640 if ( $savepointId === self::$NOT_APPLICABLE ) {
3641 $this->rollback( $fname, self::FLUSHING_INTERNAL );
3642 } else {
3643 $this->doRollbackToSavepoint( $savepointId, $fname );
3644 $this->trxStatus = self::STATUS_TRX_OK; // no exception; recovered
3645 $this->trxStatusIgnoredCause = null;
3646 }
3647 } elseif ( $this->trxStatus > self::STATUS_TRX_ERROR ) {
3648 // Put the transaction into an error state if it's not already in one
3649 $this->trxStatus = self::STATUS_TRX_ERROR;
3650 $this->trxStatusCause = new DBUnexpectedError(
3651 $this,
3652 "Uncancelable atomic section canceled (got $fname)."
3653 );
3654 }
3655
3656 $this->affectedRowCount = 0; // for the sake of consistency
3657 }
3658
3659 final public function doAtomicSection(
3660 $fname, callable $callback, $cancelable = self::ATOMIC_NOT_CANCELABLE
3661 ) {
3662 $sectionId = $this->startAtomic( $fname, $cancelable );
3663 try {
3664 $res = call_user_func_array( $callback, [ $this, $fname ] );
3665 } catch ( Exception $e ) {
3666 $this->cancelAtomic( $fname, $sectionId );
3667
3668 throw $e;
3669 }
3670 $this->endAtomic( $fname );
3671
3672 return $res;
3673 }
3674
3675 final public function begin( $fname = __METHOD__, $mode = self::TRANSACTION_EXPLICIT ) {
3676 static $modes = [ self::TRANSACTION_EXPLICIT, self::TRANSACTION_INTERNAL ];
3677 if ( !in_array( $mode, $modes, true ) ) {
3678 throw new DBUnexpectedError( $this, "$fname: invalid mode parameter '$mode'." );
3679 }
3680
3681 // Protect against mismatched atomic section, transaction nesting, and snapshot loss
3682 if ( $this->trxLevel ) {
3683 if ( $this->trxAtomicLevels ) {
3684 $levels = $this->flatAtomicSectionList();
3685 $msg = "$fname: Got explicit BEGIN while atomic section(s) $levels are open.";
3686 throw new DBUnexpectedError( $this, $msg );
3687 } elseif ( !$this->trxAutomatic ) {
3688 $msg = "$fname: Explicit transaction already active (from {$this->trxFname}).";
3689 throw new DBUnexpectedError( $this, $msg );
3690 } else {
3691 $msg = "$fname: Implicit transaction already active (from {$this->trxFname}).";
3692 throw new DBUnexpectedError( $this, $msg );
3693 }
3694 } elseif ( $this->getFlag( self::DBO_TRX ) && $mode !== self::TRANSACTION_INTERNAL ) {
3695 $msg = "$fname: Implicit transaction expected (DBO_TRX set).";
3696 throw new DBUnexpectedError( $this, $msg );
3697 }
3698
3699 // Avoid fatals if close() was called
3700 $this->assertOpen();
3701
3702 $this->doBegin( $fname );
3703 $this->trxStatus = self::STATUS_TRX_OK;
3704 $this->trxStatusIgnoredCause = null;
3705 $this->trxAtomicCounter = 0;
3706 $this->trxTimestamp = microtime( true );
3707 $this->trxFname = $fname;
3708 $this->trxDoneWrites = false;
3709 $this->trxAutomaticAtomic = false;
3710 $this->trxAtomicLevels = [];
3711 $this->trxShortId = sprintf( '%06x', mt_rand( 0, 0xffffff ) );
3712 $this->trxWriteDuration = 0.0;
3713 $this->trxWriteQueryCount = 0;
3714 $this->trxWriteAffectedRows = 0;
3715 $this->trxWriteAdjDuration = 0.0;
3716 $this->trxWriteAdjQueryCount = 0;
3717 $this->trxWriteCallers = [];
3718 // First SELECT after BEGIN will establish the snapshot in REPEATABLE-READ.
3719 // Get an estimate of the replication lag before any such queries.
3720 $this->trxReplicaLag = null; // clear cached value first
3721 $this->trxReplicaLag = $this->getApproximateLagStatus()['lag'];
3722 // T147697: make explicitTrxActive() return true until begin() finishes. This way, no
3723 // caller will think its OK to muck around with the transaction just because startAtomic()
3724 // has not yet completed (e.g. setting trxAtomicLevels).
3725 $this->trxAutomatic = ( $mode === self::TRANSACTION_INTERNAL );
3726 }
3727
3728 /**
3729 * Issues the BEGIN command to the database server.
3730 *
3731 * @see Database::begin()
3732 * @param string $fname
3733 */
3734 protected function doBegin( $fname ) {
3735 $this->query( 'BEGIN', $fname );
3736 $this->trxLevel = 1;
3737 }
3738
3739 final public function commit( $fname = __METHOD__, $flush = self::FLUSHING_ONE ) {
3740 static $modes = [ self::FLUSHING_ONE, self::FLUSHING_ALL_PEERS, self::FLUSHING_INTERNAL ];
3741 if ( !in_array( $flush, $modes, true ) ) {
3742 throw new DBUnexpectedError( $this, "$fname: invalid flush parameter '$flush'." );
3743 }
3744
3745 if ( $this->trxLevel && $this->trxAtomicLevels ) {
3746 // There are still atomic sections open; this cannot be ignored
3747 $levels = $this->flatAtomicSectionList();
3748 throw new DBUnexpectedError(
3749 $this,
3750 "$fname: Got COMMIT while atomic sections $levels are still open."
3751 );
3752 }
3753
3754 if ( $flush === self::FLUSHING_INTERNAL || $flush === self::FLUSHING_ALL_PEERS ) {
3755 if ( !$this->trxLevel ) {
3756 return; // nothing to do
3757 } elseif ( !$this->trxAutomatic ) {
3758 throw new DBUnexpectedError(
3759 $this,
3760 "$fname: Flushing an explicit transaction, getting out of sync."
3761 );
3762 }
3763 } else {
3764 if ( !$this->trxLevel ) {
3765 $this->queryLogger->error(
3766 "$fname: No transaction to commit, something got out of sync." );
3767 return; // nothing to do
3768 } elseif ( $this->trxAutomatic ) {
3769 throw new DBUnexpectedError(
3770 $this,
3771 "$fname: Expected mass commit of all peer transactions (DBO_TRX set)."
3772 );
3773 }
3774 }
3775
3776 // Avoid fatals if close() was called
3777 $this->assertOpen();
3778
3779 $this->runOnTransactionPreCommitCallbacks();
3780 $writeTime = $this->pendingWriteQueryDuration( self::ESTIMATE_DB_APPLY );
3781 $this->doCommit( $fname );
3782 $this->trxStatus = self::STATUS_TRX_NONE;
3783 if ( $this->trxDoneWrites ) {
3784 $this->lastWriteTime = microtime( true );
3785 $this->trxProfiler->transactionWritingOut(
3786 $this->server,
3787 $this->dbName,
3788 $this->trxShortId,
3789 $writeTime,
3790 $this->trxWriteAffectedRows
3791 );
3792 }
3793
3794 $this->runOnTransactionIdleCallbacks( self::TRIGGER_COMMIT );
3795 $this->runTransactionListenerCallbacks( self::TRIGGER_COMMIT );
3796 }
3797
3798 /**
3799 * Issues the COMMIT command to the database server.
3800 *
3801 * @see Database::commit()
3802 * @param string $fname
3803 */
3804 protected function doCommit( $fname ) {
3805 if ( $this->trxLevel ) {
3806 $this->query( 'COMMIT', $fname );
3807 $this->trxLevel = 0;
3808 }
3809 }
3810
3811 final public function rollback( $fname = __METHOD__, $flush = '' ) {
3812 $trxActive = $this->trxLevel;
3813
3814 if ( $flush !== self::FLUSHING_INTERNAL && $flush !== self::FLUSHING_ALL_PEERS ) {
3815 if ( $this->getFlag( self::DBO_TRX ) ) {
3816 throw new DBUnexpectedError(
3817 $this,
3818 "$fname: Expected mass rollback of all peer transactions (DBO_TRX set)."
3819 );
3820 }
3821 }
3822
3823 if ( $trxActive ) {
3824 // Avoid fatals if close() was called
3825 $this->assertOpen();
3826
3827 $this->doRollback( $fname );
3828 $this->trxStatus = self::STATUS_TRX_NONE;
3829 $this->trxAtomicLevels = [];
3830 if ( $this->trxDoneWrites ) {
3831 $this->trxProfiler->transactionWritingOut(
3832 $this->server,
3833 $this->dbName,
3834 $this->trxShortId
3835 );
3836 }
3837 }
3838
3839 // Clear any commit-dependant callbacks. They might even be present
3840 // only due to transaction rounds, with no SQL transaction being active
3841 $this->trxIdleCallbacks = [];
3842 $this->trxPreCommitCallbacks = [];
3843
3844 if ( $trxActive ) {
3845 try {
3846 $this->runOnTransactionIdleCallbacks( self::TRIGGER_ROLLBACK );
3847 } catch ( Exception $e ) {
3848 // already logged; finish and let LoadBalancer move on during mass-rollback
3849 }
3850 try {
3851 $this->runTransactionListenerCallbacks( self::TRIGGER_ROLLBACK );
3852 } catch ( Exception $e ) {
3853 // already logged; let LoadBalancer move on during mass-rollback
3854 }
3855
3856 $this->affectedRowCount = 0; // for the sake of consistency
3857 }
3858 }
3859
3860 /**
3861 * Issues the ROLLBACK command to the database server.
3862 *
3863 * @see Database::rollback()
3864 * @param string $fname
3865 */
3866 protected function doRollback( $fname ) {
3867 if ( $this->trxLevel ) {
3868 # Disconnects cause rollback anyway, so ignore those errors
3869 $ignoreErrors = true;
3870 $this->query( 'ROLLBACK', $fname, $ignoreErrors );
3871 $this->trxLevel = 0;
3872 }
3873 }
3874
3875 public function flushSnapshot( $fname = __METHOD__ ) {
3876 if ( $this->writesOrCallbacksPending() || $this->explicitTrxActive() ) {
3877 // This only flushes transactions to clear snapshots, not to write data
3878 $fnames = implode( ', ', $this->pendingWriteAndCallbackCallers() );
3879 throw new DBUnexpectedError(
3880 $this,
3881 "$fname: Cannot flush snapshot because writes are pending ($fnames)."
3882 );
3883 }
3884
3885 $this->commit( $fname, self::FLUSHING_INTERNAL );
3886 }
3887
3888 public function explicitTrxActive() {
3889 return $this->trxLevel && ( $this->trxAtomicLevels || !$this->trxAutomatic );
3890 }
3891
3892 public function duplicateTableStructure(
3893 $oldName, $newName, $temporary = false, $fname = __METHOD__
3894 ) {
3895 throw new RuntimeException( __METHOD__ . ' is not implemented in descendant class' );
3896 }
3897
3898 public function listTables( $prefix = null, $fname = __METHOD__ ) {
3899 throw new RuntimeException( __METHOD__ . ' is not implemented in descendant class' );
3900 }
3901
3902 public function listViews( $prefix = null, $fname = __METHOD__ ) {
3903 throw new RuntimeException( __METHOD__ . ' is not implemented in descendant class' );
3904 }
3905
3906 public function timestamp( $ts = 0 ) {
3907 $t = new ConvertibleTimestamp( $ts );
3908 // Let errors bubble up to avoid putting garbage in the DB
3909 return $t->getTimestamp( TS_MW );
3910 }
3911
3912 public function timestampOrNull( $ts = null ) {
3913 if ( is_null( $ts ) ) {
3914 return null;
3915 } else {
3916 return $this->timestamp( $ts );
3917 }
3918 }
3919
3920 public function affectedRows() {
3921 return ( $this->affectedRowCount === null )
3922 ? $this->fetchAffectedRowCount() // default to driver value
3923 : $this->affectedRowCount;
3924 }
3925
3926 /**
3927 * @return int Number of retrieved rows according to the driver
3928 */
3929 abstract protected function fetchAffectedRowCount();
3930
3931 /**
3932 * Take the result from a query, and wrap it in a ResultWrapper if
3933 * necessary. Boolean values are passed through as is, to indicate success
3934 * of write queries or failure.
3935 *
3936 * Once upon a time, Database::query() returned a bare MySQL result
3937 * resource, and it was necessary to call this function to convert it to
3938 * a wrapper. Nowadays, raw database objects are never exposed to external
3939 * callers, so this is unnecessary in external code.
3940 *
3941 * @param bool|ResultWrapper|resource|object $result
3942 * @return bool|ResultWrapper
3943 */
3944 protected function resultObject( $result ) {
3945 if ( !$result ) {
3946 return false;
3947 } elseif ( $result instanceof ResultWrapper ) {
3948 return $result;
3949 } elseif ( $result === true ) {
3950 // Successful write query
3951 return $result;
3952 } else {
3953 return new ResultWrapper( $this, $result );
3954 }
3955 }
3956
3957 public function ping( &$rtt = null ) {
3958 // Avoid hitting the server if it was hit recently
3959 if ( $this->isOpen() && ( microtime( true ) - $this->lastPing ) < self::PING_TTL ) {
3960 if ( !func_num_args() || $this->rttEstimate > 0 ) {
3961 $rtt = $this->rttEstimate;
3962 return true; // don't care about $rtt
3963 }
3964 }
3965
3966 // This will reconnect if possible or return false if not
3967 $this->clearFlag( self::DBO_TRX, self::REMEMBER_PRIOR );
3968 $ok = ( $this->query( self::PING_QUERY, __METHOD__, true ) !== false );
3969 $this->restoreFlags( self::RESTORE_PRIOR );
3970
3971 if ( $ok ) {
3972 $rtt = $this->rttEstimate;
3973 }
3974
3975 return $ok;
3976 }
3977
3978 /**
3979 * Close any existing (dead) database connection and open a new connection
3980 *
3981 * @param string $fname
3982 * @return bool True if new connection is opened successfully, false if error
3983 */
3984 protected function replaceLostConnection( $fname ) {
3985 $this->closeConnection();
3986 $this->opened = false;
3987 $this->conn = false;
3988 try {
3989 $this->open( $this->server, $this->user, $this->password, $this->dbName );
3990 $this->lastPing = microtime( true );
3991 $ok = true;
3992
3993 $this->connLogger->warning(
3994 $fname . ': lost connection to {dbserver}; reconnected',
3995 [
3996 'dbserver' => $this->getServer(),
3997 'trace' => ( new RuntimeException() )->getTraceAsString()
3998 ]
3999 );
4000 } catch ( DBConnectionError $e ) {
4001 $ok = false;
4002
4003 $this->connLogger->error(
4004 $fname . ': lost connection to {dbserver} permanently',
4005 [ 'dbserver' => $this->getServer() ]
4006 );
4007 }
4008
4009 $this->handleSessionLoss();
4010
4011 return $ok;
4012 }
4013
4014 public function getSessionLagStatus() {
4015 return $this->getRecordedTransactionLagStatus() ?: $this->getApproximateLagStatus();
4016 }
4017
4018 /**
4019 * Get the replica DB lag when the current transaction started
4020 *
4021 * This is useful when transactions might use snapshot isolation
4022 * (e.g. REPEATABLE-READ in innodb), so the "real" lag of that data
4023 * is this lag plus transaction duration. If they don't, it is still
4024 * safe to be pessimistic. This returns null if there is no transaction.
4025 *
4026 * This returns null if the lag status for this transaction was not yet recorded.
4027 *
4028 * @return array|null ('lag': seconds or false on error, 'since': UNIX timestamp of BEGIN)
4029 * @since 1.27
4030 */
4031 final protected function getRecordedTransactionLagStatus() {
4032 return ( $this->trxLevel && $this->trxReplicaLag !== null )
4033 ? [ 'lag' => $this->trxReplicaLag, 'since' => $this->trxTimestamp() ]
4034 : null;
4035 }
4036
4037 /**
4038 * Get a replica DB lag estimate for this server
4039 *
4040 * @return array ('lag': seconds or false on error, 'since': UNIX timestamp of estimate)
4041 * @since 1.27
4042 */
4043 protected function getApproximateLagStatus() {
4044 return [
4045 'lag' => $this->getLBInfo( 'replica' ) ? $this->getLag() : 0,
4046 'since' => microtime( true )
4047 ];
4048 }
4049
4050 /**
4051 * Merge the result of getSessionLagStatus() for several DBs
4052 * using the most pessimistic values to estimate the lag of
4053 * any data derived from them in combination
4054 *
4055 * This is information is useful for caching modules
4056 *
4057 * @see WANObjectCache::set()
4058 * @see WANObjectCache::getWithSetCallback()
4059 *
4060 * @param IDatabase $db1
4061 * @param IDatabase $db2 [optional]
4062 * @return array Map of values:
4063 * - lag: highest lag of any of the DBs or false on error (e.g. replication stopped)
4064 * - since: oldest UNIX timestamp of any of the DB lag estimates
4065 * - pending: whether any of the DBs have uncommitted changes
4066 * @throws DBError
4067 * @since 1.27
4068 */
4069 public static function getCacheSetOptions( IDatabase $db1, IDatabase $db2 = null ) {
4070 $res = [ 'lag' => 0, 'since' => INF, 'pending' => false ];
4071 foreach ( func_get_args() as $db ) {
4072 /** @var IDatabase $db */
4073 $status = $db->getSessionLagStatus();
4074 if ( $status['lag'] === false ) {
4075 $res['lag'] = false;
4076 } elseif ( $res['lag'] !== false ) {
4077 $res['lag'] = max( $res['lag'], $status['lag'] );
4078 }
4079 $res['since'] = min( $res['since'], $status['since'] );
4080 $res['pending'] = $res['pending'] ?: $db->writesPending();
4081 }
4082
4083 return $res;
4084 }
4085
4086 public function getLag() {
4087 return 0;
4088 }
4089
4090 public function maxListLen() {
4091 return 0;
4092 }
4093
4094 public function encodeBlob( $b ) {
4095 return $b;
4096 }
4097
4098 public function decodeBlob( $b ) {
4099 if ( $b instanceof Blob ) {
4100 $b = $b->fetch();
4101 }
4102 return $b;
4103 }
4104
4105 public function setSessionOptions( array $options ) {
4106 }
4107
4108 public function sourceFile(
4109 $filename,
4110 callable $lineCallback = null,
4111 callable $resultCallback = null,
4112 $fname = false,
4113 callable $inputCallback = null
4114 ) {
4115 Wikimedia\suppressWarnings();
4116 $fp = fopen( $filename, 'r' );
4117 Wikimedia\restoreWarnings();
4118
4119 if ( false === $fp ) {
4120 throw new RuntimeException( "Could not open \"{$filename}\".\n" );
4121 }
4122
4123 if ( !$fname ) {
4124 $fname = __METHOD__ . "( $filename )";
4125 }
4126
4127 try {
4128 $error = $this->sourceStream(
4129 $fp, $lineCallback, $resultCallback, $fname, $inputCallback );
4130 } catch ( Exception $e ) {
4131 fclose( $fp );
4132 throw $e;
4133 }
4134
4135 fclose( $fp );
4136
4137 return $error;
4138 }
4139
4140 public function setSchemaVars( $vars ) {
4141 $this->schemaVars = $vars;
4142 }
4143
4144 public function sourceStream(
4145 $fp,
4146 callable $lineCallback = null,
4147 callable $resultCallback = null,
4148 $fname = __METHOD__,
4149 callable $inputCallback = null
4150 ) {
4151 $delimiterReset = new ScopedCallback(
4152 function ( $delimiter ) {
4153 $this->delimiter = $delimiter;
4154 },
4155 [ $this->delimiter ]
4156 );
4157 $cmd = '';
4158
4159 while ( !feof( $fp ) ) {
4160 if ( $lineCallback ) {
4161 call_user_func( $lineCallback );
4162 }
4163
4164 $line = trim( fgets( $fp ) );
4165
4166 if ( $line == '' ) {
4167 continue;
4168 }
4169
4170 if ( '-' == $line[0] && '-' == $line[1] ) {
4171 continue;
4172 }
4173
4174 if ( $cmd != '' ) {
4175 $cmd .= ' ';
4176 }
4177
4178 $done = $this->streamStatementEnd( $cmd, $line );
4179
4180 $cmd .= "$line\n";
4181
4182 if ( $done || feof( $fp ) ) {
4183 $cmd = $this->replaceVars( $cmd );
4184
4185 if ( $inputCallback ) {
4186 $callbackResult = call_user_func( $inputCallback, $cmd );
4187
4188 if ( is_string( $callbackResult ) || !$callbackResult ) {
4189 $cmd = $callbackResult;
4190 }
4191 }
4192
4193 if ( $cmd ) {
4194 $res = $this->query( $cmd, $fname );
4195
4196 if ( $resultCallback ) {
4197 call_user_func( $resultCallback, $res, $this );
4198 }
4199
4200 if ( false === $res ) {
4201 $err = $this->lastError();
4202
4203 return "Query \"{$cmd}\" failed with error code \"$err\".\n";
4204 }
4205 }
4206 $cmd = '';
4207 }
4208 }
4209
4210 ScopedCallback::consume( $delimiterReset );
4211 return true;
4212 }
4213
4214 /**
4215 * Called by sourceStream() to check if we've reached a statement end
4216 *
4217 * @param string &$sql SQL assembled so far
4218 * @param string &$newLine New line about to be added to $sql
4219 * @return bool Whether $newLine contains end of the statement
4220 */
4221 public function streamStatementEnd( &$sql, &$newLine ) {
4222 if ( $this->delimiter ) {
4223 $prev = $newLine;
4224 $newLine = preg_replace(
4225 '/' . preg_quote( $this->delimiter, '/' ) . '$/', '', $newLine );
4226 if ( $newLine != $prev ) {
4227 return true;
4228 }
4229 }
4230
4231 return false;
4232 }
4233
4234 /**
4235 * Database independent variable replacement. Replaces a set of variables
4236 * in an SQL statement with their contents as given by $this->getSchemaVars().
4237 *
4238 * Supports '{$var}' `{$var}` and / *$var* / (without the spaces) style variables.
4239 *
4240 * - '{$var}' should be used for text and is passed through the database's
4241 * addQuotes method.
4242 * - `{$var}` should be used for identifiers (e.g. table and database names).
4243 * It is passed through the database's addIdentifierQuotes method which
4244 * can be overridden if the database uses something other than backticks.
4245 * - / *_* / or / *$wgDBprefix* / passes the name that follows through the
4246 * database's tableName method.
4247 * - / *i* / passes the name that follows through the database's indexName method.
4248 * - In all other cases, / *$var* / is left unencoded. Except for table options,
4249 * its use should be avoided. In 1.24 and older, string encoding was applied.
4250 *
4251 * @param string $ins SQL statement to replace variables in
4252 * @return string The new SQL statement with variables replaced
4253 */
4254 protected function replaceVars( $ins ) {
4255 $vars = $this->getSchemaVars();
4256 return preg_replace_callback(
4257 '!
4258 /\* (\$wgDBprefix|[_i]) \*/ (\w*) | # 1-2. tableName, indexName
4259 \'\{\$ (\w+) }\' | # 3. addQuotes
4260 `\{\$ (\w+) }` | # 4. addIdentifierQuotes
4261 /\*\$ (\w+) \*/ # 5. leave unencoded
4262 !x',
4263 function ( $m ) use ( $vars ) {
4264 // Note: Because of <https://bugs.php.net/bug.php?id=51881>,
4265 // check for both nonexistent keys *and* the empty string.
4266 if ( isset( $m[1] ) && $m[1] !== '' ) {
4267 if ( $m[1] === 'i' ) {
4268 return $this->indexName( $m[2] );
4269 } else {
4270 return $this->tableName( $m[2] );
4271 }
4272 } elseif ( isset( $m[3] ) && $m[3] !== '' && array_key_exists( $m[3], $vars ) ) {
4273 return $this->addQuotes( $vars[$m[3]] );
4274 } elseif ( isset( $m[4] ) && $m[4] !== '' && array_key_exists( $m[4], $vars ) ) {
4275 return $this->addIdentifierQuotes( $vars[$m[4]] );
4276 } elseif ( isset( $m[5] ) && $m[5] !== '' && array_key_exists( $m[5], $vars ) ) {
4277 return $vars[$m[5]];
4278 } else {
4279 return $m[0];
4280 }
4281 },
4282 $ins
4283 );
4284 }
4285
4286 /**
4287 * Get schema variables. If none have been set via setSchemaVars(), then
4288 * use some defaults from the current object.
4289 *
4290 * @return array
4291 */
4292 protected function getSchemaVars() {
4293 if ( $this->schemaVars ) {
4294 return $this->schemaVars;
4295 } else {
4296 return $this->getDefaultSchemaVars();
4297 }
4298 }
4299
4300 /**
4301 * Get schema variables to use if none have been set via setSchemaVars().
4302 *
4303 * Override this in derived classes to provide variables for tables.sql
4304 * and SQL patch files.
4305 *
4306 * @return array
4307 */
4308 protected function getDefaultSchemaVars() {
4309 return [];
4310 }
4311
4312 public function lockIsFree( $lockName, $method ) {
4313 // RDBMs methods for checking named locks may or may not count this thread itself.
4314 // In MySQL, IS_FREE_LOCK() returns 0 if the thread already has the lock. This is
4315 // the behavior choosen by the interface for this method.
4316 return !isset( $this->namedLocksHeld[$lockName] );
4317 }
4318
4319 public function lock( $lockName, $method, $timeout = 5 ) {
4320 $this->namedLocksHeld[$lockName] = 1;
4321
4322 return true;
4323 }
4324
4325 public function unlock( $lockName, $method ) {
4326 unset( $this->namedLocksHeld[$lockName] );
4327
4328 return true;
4329 }
4330
4331 public function getScopedLockAndFlush( $lockKey, $fname, $timeout ) {
4332 if ( $this->writesOrCallbacksPending() ) {
4333 // This only flushes transactions to clear snapshots, not to write data
4334 $fnames = implode( ', ', $this->pendingWriteAndCallbackCallers() );
4335 throw new DBUnexpectedError(
4336 $this,
4337 "$fname: Cannot flush pre-lock snapshot because writes are pending ($fnames)."
4338 );
4339 }
4340
4341 if ( !$this->lock( $lockKey, $fname, $timeout ) ) {
4342 return null;
4343 }
4344
4345 $unlocker = new ScopedCallback( function () use ( $lockKey, $fname ) {
4346 if ( $this->trxLevel() ) {
4347 // There is a good chance an exception was thrown, causing any early return
4348 // from the caller. Let any error handler get a chance to issue rollback().
4349 // If there isn't one, let the error bubble up and trigger server-side rollback.
4350 $this->onTransactionResolution(
4351 function () use ( $lockKey, $fname ) {
4352 $this->unlock( $lockKey, $fname );
4353 },
4354 $fname
4355 );
4356 } else {
4357 $this->unlock( $lockKey, $fname );
4358 }
4359 } );
4360
4361 $this->commit( $fname, self::FLUSHING_INTERNAL );
4362
4363 return $unlocker;
4364 }
4365
4366 public function namedLocksEnqueue() {
4367 return false;
4368 }
4369
4370 public function tableLocksHaveTransactionScope() {
4371 return true;
4372 }
4373
4374 final public function lockTables( array $read, array $write, $method ) {
4375 if ( $this->writesOrCallbacksPending() ) {
4376 throw new DBUnexpectedError( $this, "Transaction writes or callbacks still pending." );
4377 }
4378
4379 if ( $this->tableLocksHaveTransactionScope() ) {
4380 $this->startAtomic( $method );
4381 }
4382
4383 return $this->doLockTables( $read, $write, $method );
4384 }
4385
4386 /**
4387 * Helper function for lockTables() that handles the actual table locking
4388 *
4389 * @param array $read Array of tables to lock for read access
4390 * @param array $write Array of tables to lock for write access
4391 * @param string $method Name of caller
4392 * @return true
4393 */
4394 protected function doLockTables( array $read, array $write, $method ) {
4395 return true;
4396 }
4397
4398 final public function unlockTables( $method ) {
4399 if ( $this->tableLocksHaveTransactionScope() ) {
4400 $this->endAtomic( $method );
4401
4402 return true; // locks released on COMMIT/ROLLBACK
4403 }
4404
4405 return $this->doUnlockTables( $method );
4406 }
4407
4408 /**
4409 * Helper function for unlockTables() that handles the actual table unlocking
4410 *
4411 * @param string $method Name of caller
4412 * @return true
4413 */
4414 protected function doUnlockTables( $method ) {
4415 return true;
4416 }
4417
4418 /**
4419 * Delete a table
4420 * @param string $tableName
4421 * @param string $fName
4422 * @return bool|ResultWrapper
4423 * @since 1.18
4424 */
4425 public function dropTable( $tableName, $fName = __METHOD__ ) {
4426 if ( !$this->tableExists( $tableName, $fName ) ) {
4427 return false;
4428 }
4429 $sql = "DROP TABLE " . $this->tableName( $tableName ) . " CASCADE";
4430
4431 return $this->query( $sql, $fName );
4432 }
4433
4434 public function getInfinity() {
4435 return 'infinity';
4436 }
4437
4438 public function encodeExpiry( $expiry ) {
4439 return ( $expiry == '' || $expiry == 'infinity' || $expiry == $this->getInfinity() )
4440 ? $this->getInfinity()
4441 : $this->timestamp( $expiry );
4442 }
4443
4444 public function decodeExpiry( $expiry, $format = TS_MW ) {
4445 if ( $expiry == '' || $expiry == 'infinity' || $expiry == $this->getInfinity() ) {
4446 return 'infinity';
4447 }
4448
4449 return ConvertibleTimestamp::convert( $format, $expiry );
4450 }
4451
4452 public function setBigSelects( $value = true ) {
4453 // no-op
4454 }
4455
4456 public function isReadOnly() {
4457 return ( $this->getReadOnlyReason() !== false );
4458 }
4459
4460 /**
4461 * @return string|bool Reason this DB is read-only or false if it is not
4462 */
4463 protected function getReadOnlyReason() {
4464 $reason = $this->getLBInfo( 'readOnlyReason' );
4465
4466 return is_string( $reason ) ? $reason : false;
4467 }
4468
4469 public function setTableAliases( array $aliases ) {
4470 $this->tableAliases = $aliases;
4471 }
4472
4473 public function setIndexAliases( array $aliases ) {
4474 $this->indexAliases = $aliases;
4475 }
4476
4477 /**
4478 * Get the underlying binding connection handle
4479 *
4480 * Makes sure the connection resource is set (disconnects and ping() failure can unset it).
4481 * This catches broken callers than catch and ignore disconnection exceptions.
4482 * Unlike checking isOpen(), this is safe to call inside of open().
4483 *
4484 * @return mixed
4485 * @throws DBUnexpectedError
4486 * @since 1.26
4487 */
4488 protected function getBindingHandle() {
4489 if ( !$this->conn ) {
4490 throw new DBUnexpectedError(
4491 $this,
4492 'DB connection was already closed or the connection dropped.'
4493 );
4494 }
4495
4496 return $this->conn;
4497 }
4498
4499 /**
4500 * @since 1.19
4501 * @return string
4502 */
4503 public function __toString() {
4504 return (string)$this->conn;
4505 }
4506
4507 /**
4508 * Make sure that copies do not share the same client binding handle
4509 * @throws DBConnectionError
4510 */
4511 public function __clone() {
4512 $this->connLogger->warning(
4513 "Cloning " . static::class . " is not recomended; forking connection:\n" .
4514 ( new RuntimeException() )->getTraceAsString()
4515 );
4516
4517 if ( $this->isOpen() ) {
4518 // Open a new connection resource without messing with the old one
4519 $this->opened = false;
4520 $this->conn = false;
4521 $this->trxEndCallbacks = []; // don't copy
4522 $this->handleSessionLoss(); // no trx or locks anymore
4523 $this->open( $this->server, $this->user, $this->password, $this->dbName );
4524 $this->lastPing = microtime( true );
4525 }
4526 }
4527
4528 /**
4529 * Called by serialize. Throw an exception when DB connection is serialized.
4530 * This causes problems on some database engines because the connection is
4531 * not restored on unserialize.
4532 */
4533 public function __sleep() {
4534 throw new RuntimeException( 'Database serialization may cause problems, since ' .
4535 'the connection is not restored on wakeup.' );
4536 }
4537
4538 /**
4539 * Run a few simple sanity checks and close dangling connections
4540 */
4541 public function __destruct() {
4542 if ( $this->trxLevel && $this->trxDoneWrites ) {
4543 trigger_error( "Uncommitted DB writes (transaction from {$this->trxFname})." );
4544 }
4545
4546 $danglingWriters = $this->pendingWriteAndCallbackCallers();
4547 if ( $danglingWriters ) {
4548 $fnames = implode( ', ', $danglingWriters );
4549 trigger_error( "DB transaction writes or callbacks still pending ($fnames)." );
4550 }
4551
4552 if ( $this->conn ) {
4553 // Avoid connection leaks for sanity. Normally, resources close at script completion.
4554 // The connection might already be closed in zend/hhvm by now, so suppress warnings.
4555 Wikimedia\suppressWarnings();
4556 $this->closeConnection();
4557 Wikimedia\restoreWarnings();
4558 $this->conn = false;
4559 $this->opened = false;
4560 }
4561 }
4562 }
4563
4564 class_alias( Database::class, 'DatabaseBase' ); // b/c for old name
4565 class_alias( Database::class, 'Database' ); // b/c global alias
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