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Replace misplaced strlen() checks with strict `false` comparisons
[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 array[] Map of (table => (dbname, schema, prefix) map) */
85 protected $tableAliases = [];
86 /** @var string[] Map of (index alias => index) */
87 protected $indexAliases = [];
88 /** @var bool Whether this PHP instance is for a CLI script */
89 protected $cliMode;
90 /** @var string Agent name for query profiling */
91 protected $agent;
92 /** @var array Parameters used by initConnection() to establish a connection */
93 protected $connectionParams = [];
94 /** @var BagOStuff APC cache */
95 protected $srvCache;
96 /** @var LoggerInterface */
97 protected $connLogger;
98 /** @var LoggerInterface */
99 protected $queryLogger;
100 /** @var callable Error logging callback */
101 protected $errorLogger;
102 /** @var callable Deprecation logging callback */
103 protected $deprecationLogger;
104
105 /** @var resource|null Database connection */
106 protected $conn = null;
107 /** @var bool */
108 protected $opened = false;
109
110 /** @var array[] List of (callable, method name, atomic section id) */
111 protected $trxIdleCallbacks = [];
112 /** @var array[] List of (callable, method name, atomic section id) */
113 protected $trxPreCommitCallbacks = [];
114 /** @var array[] List of (callable, method name, atomic section id) */
115 protected $trxEndCallbacks = [];
116 /** @var callable[] Map of (name => callable) */
117 protected $trxRecurringCallbacks = [];
118 /** @var bool Whether to suppress triggering of transaction end callbacks */
119 protected $trxEndCallbacksSuppressed = false;
120
121 /** @var int */
122 protected $flags;
123 /** @var array */
124 protected $lbInfo = [];
125 /** @var array|bool */
126 protected $schemaVars = false;
127 /** @var array */
128 protected $sessionVars = [];
129 /** @var array|null */
130 protected $preparedArgs;
131 /** @var string|bool|null Stashed value of html_errors INI setting */
132 protected $htmlErrors;
133 /** @var string */
134 protected $delimiter = ';';
135 /** @var DatabaseDomain */
136 protected $currentDomain;
137 /** @var integer|null Rows affected by the last query to query() or its CRUD wrappers */
138 protected $affectedRowCount;
139
140 /**
141 * @var int Transaction status
142 */
143 protected $trxStatus = self::STATUS_TRX_NONE;
144 /**
145 * @var Exception|null The last error that caused the status to become STATUS_TRX_ERROR
146 */
147 protected $trxStatusCause;
148 /**
149 * @var array|null If wasKnownStatementRollbackError() prevented trxStatus from being set,
150 * the relevant details are stored here.
151 */
152 protected $trxStatusIgnoredCause;
153 /**
154 * Either 1 if a transaction is active or 0 otherwise.
155 * The other Trx fields may not be meaningfull if this is 0.
156 *
157 * @var int
158 */
159 protected $trxLevel = 0;
160 /**
161 * Either a short hexidecimal string if a transaction is active or ""
162 *
163 * @var string
164 * @see Database::trxLevel
165 */
166 protected $trxShortId = '';
167 /**
168 * The UNIX time that the transaction started. Callers can assume that if
169 * snapshot isolation is used, then the data is *at least* up to date to that
170 * point (possibly more up-to-date since the first SELECT defines the snapshot).
171 *
172 * @var float|null
173 * @see Database::trxLevel
174 */
175 private $trxTimestamp = null;
176 /** @var float Lag estimate at the time of BEGIN */
177 private $trxReplicaLag = null;
178 /**
179 * Remembers the function name given for starting the most recent transaction via begin().
180 * Used to provide additional context for error reporting.
181 *
182 * @var string
183 * @see Database::trxLevel
184 */
185 private $trxFname = null;
186 /**
187 * Record if possible write queries were done in the last transaction started
188 *
189 * @var bool
190 * @see Database::trxLevel
191 */
192 private $trxDoneWrites = false;
193 /**
194 * Record if the current transaction was started implicitly due to DBO_TRX being set.
195 *
196 * @var bool
197 * @see Database::trxLevel
198 */
199 private $trxAutomatic = false;
200 /**
201 * Counter for atomic savepoint identifiers. Reset when a new transaction begins.
202 *
203 * @var int
204 */
205 private $trxAtomicCounter = 0;
206 /**
207 * Array of levels of atomicity within transactions
208 *
209 * @var array List of (name, unique ID, savepoint ID)
210 */
211 private $trxAtomicLevels = [];
212 /**
213 * Record if the current transaction was started implicitly by Database::startAtomic
214 *
215 * @var bool
216 */
217 private $trxAutomaticAtomic = false;
218 /**
219 * Track the write query callers of the current transaction
220 *
221 * @var string[]
222 */
223 private $trxWriteCallers = [];
224 /**
225 * @var float Seconds spent in write queries for the current transaction
226 */
227 private $trxWriteDuration = 0.0;
228 /**
229 * @var int Number of write queries for the current transaction
230 */
231 private $trxWriteQueryCount = 0;
232 /**
233 * @var int Number of rows affected by write queries for the current transaction
234 */
235 private $trxWriteAffectedRows = 0;
236 /**
237 * @var float Like trxWriteQueryCount but excludes lock-bound, easy to replicate, queries
238 */
239 private $trxWriteAdjDuration = 0.0;
240 /**
241 * @var int Number of write queries counted in trxWriteAdjDuration
242 */
243 private $trxWriteAdjQueryCount = 0;
244 /**
245 * @var float RTT time estimate
246 */
247 private $rttEstimate = 0.0;
248
249 /** @var array Map of (name => 1) for locks obtained via lock() */
250 private $namedLocksHeld = [];
251 /** @var array Map of (table name => 1) for TEMPORARY tables */
252 protected $sessionTempTables = [];
253
254 /** @var IDatabase|null Lazy handle to the master DB this server replicates from */
255 private $lazyMasterHandle;
256
257 /** @var float UNIX timestamp */
258 protected $lastPing = 0.0;
259
260 /** @var int[] Prior flags member variable values */
261 private $priorFlags = [];
262
263 /** @var callable|null */
264 protected $profiler;
265 /** @var TransactionProfiler */
266 protected $trxProfiler;
267
268 /** @var int */
269 protected $nonNativeInsertSelectBatchSize = 10000;
270
271 /** @var string Idiom used when a cancelable atomic section started the transaction */
272 private static $NOT_APPLICABLE = 'n/a';
273 /** @var string Prefix to the atomic section counter used to make savepoint IDs */
274 private static $SAVEPOINT_PREFIX = 'wikimedia_rdbms_atomic';
275
276 /** @var int Transaction is in a error state requiring a full or savepoint rollback */
277 const STATUS_TRX_ERROR = 1;
278 /** @var int Transaction is active and in a normal state */
279 const STATUS_TRX_OK = 2;
280 /** @var int No transaction is active */
281 const STATUS_TRX_NONE = 3;
282
283 /** @var int Writes to this temporary table do not affect lastDoneWrites() */
284 const TEMP_NORMAL = 1;
285 /** @var int Writes to this temporary table effect lastDoneWrites() */
286 const TEMP_PSEUDO_PERMANENT = 2;
287
288 /**
289 * @note exceptions for missing libraries/drivers should be thrown in initConnection()
290 * @param array $params Parameters passed from Database::factory()
291 */
292 protected function __construct( array $params ) {
293 foreach ( [ 'host', 'user', 'password', 'dbname', 'schema', 'tablePrefix' ] as $name ) {
294 $this->connectionParams[$name] = $params[$name];
295 }
296
297 $this->cliMode = $params['cliMode'];
298 // Agent name is added to SQL queries in a comment, so make sure it can't break out
299 $this->agent = str_replace( '/', '-', $params['agent'] );
300
301 $this->flags = $params['flags'];
302 if ( $this->flags & self::DBO_DEFAULT ) {
303 if ( $this->cliMode ) {
304 $this->flags &= ~self::DBO_TRX;
305 } else {
306 $this->flags |= self::DBO_TRX;
307 }
308 }
309 // Disregard deprecated DBO_IGNORE flag (T189999)
310 $this->flags &= ~self::DBO_IGNORE;
311
312 $this->sessionVars = $params['variables'];
313
314 $this->srvCache = $params['srvCache'] ?? new HashBagOStuff();
315
316 $this->profiler = is_callable( $params['profiler'] ) ? $params['profiler'] : null;
317 $this->trxProfiler = $params['trxProfiler'];
318 $this->connLogger = $params['connLogger'];
319 $this->queryLogger = $params['queryLogger'];
320 $this->errorLogger = $params['errorLogger'];
321 $this->deprecationLogger = $params['deprecationLogger'];
322
323 if ( isset( $params['nonNativeInsertSelectBatchSize'] ) ) {
324 $this->nonNativeInsertSelectBatchSize = $params['nonNativeInsertSelectBatchSize'];
325 }
326
327 // Set initial dummy domain until open() sets the final DB/prefix
328 $this->currentDomain = new DatabaseDomain(
329 $params['dbname'] != '' ? $params['dbname'] : null,
330 $params['schema'] != '' ? $params['schema'] : null,
331 $params['tablePrefix']
332 );
333 }
334
335 /**
336 * Initialize the connection to the database over the wire (or to local files)
337 *
338 * @throws LogicException
339 * @throws InvalidArgumentException
340 * @throws DBConnectionError
341 * @since 1.31
342 */
343 final public function initConnection() {
344 if ( $this->isOpen() ) {
345 throw new LogicException( __METHOD__ . ': already connected.' );
346 }
347 // Establish the connection
348 $this->doInitConnection();
349 }
350
351 /**
352 * Actually connect to the database over the wire (or to local files)
353 *
354 * @throws InvalidArgumentException
355 * @throws DBConnectionError
356 * @since 1.31
357 */
358 protected function doInitConnection() {
359 if ( strlen( $this->connectionParams['user'] ) ) {
360 $this->open(
361 $this->connectionParams['host'],
362 $this->connectionParams['user'],
363 $this->connectionParams['password'],
364 $this->connectionParams['dbname'],
365 $this->connectionParams['schema'],
366 $this->connectionParams['tablePrefix']
367 );
368 } else {
369 throw new InvalidArgumentException( "No database user provided." );
370 }
371 }
372
373 /**
374 * Open a new connection to the database (closing any existing one)
375 *
376 * @param string $server Database server host
377 * @param string $user Database user name
378 * @param string $password Database user password
379 * @param string $dbName Database name
380 * @param string|null $schema Database schema name
381 * @param string $tablePrefix Table prefix
382 * @return bool
383 * @throws DBConnectionError
384 */
385 abstract protected function open( $server, $user, $password, $dbName, $schema, $tablePrefix );
386
387 /**
388 * Construct a Database subclass instance given a database type and parameters
389 *
390 * This also connects to the database immediately upon object construction
391 *
392 * @param string $dbType A possible DB type (sqlite, mysql, postgres,...)
393 * @param array $p Parameter map with keys:
394 * - host : The hostname of the DB server
395 * - user : The name of the database user the client operates under
396 * - password : The password for the database user
397 * - dbname : The name of the database to use where queries do not specify one.
398 * The database must exist or an error might be thrown. Setting this to the empty string
399 * will avoid any such errors and make the handle have no implicit database scope. This is
400 * useful for queries like SHOW STATUS, CREATE DATABASE, or DROP DATABASE. Note that a
401 * "database" in Postgres is rougly equivalent to an entire MySQL server. This the domain
402 * in which user names and such are defined, e.g. users are database-specific in Postgres.
403 * - schema : The database schema to use (if supported). A "schema" in Postgres is roughly
404 * equivalent to a "database" in MySQL. Note that MySQL and SQLite do not use schemas.
405 * - tablePrefix : Optional table prefix that is implicitly added on to all table names
406 * recognized in queries. This can be used in place of schemas for handle site farms.
407 * - flags : Optional bitfield of DBO_* constants that define connection, protocol,
408 * buffering, and transaction behavior. It is STRONGLY adviced to leave the DBO_DEFAULT
409 * flag in place UNLESS this this database simply acts as a key/value store.
410 * - driver: Optional name of a specific DB client driver. For MySQL, there is only the
411 * 'mysqli' driver; the old one 'mysql' has been removed.
412 * - variables: Optional map of session variables to set after connecting. This can be
413 * used to adjust lock timeouts or encoding modes and the like.
414 * - connLogger: Optional PSR-3 logger interface instance.
415 * - queryLogger: Optional PSR-3 logger interface instance.
416 * - profiler : Optional callback that takes a section name argument and returns
417 * a ScopedCallback instance that ends the profile section in its destructor.
418 * These will be called in query(), using a simplified version of the SQL that
419 * also includes the agent as a SQL comment.
420 * - trxProfiler: Optional TransactionProfiler instance.
421 * - errorLogger: Optional callback that takes an Exception and logs it.
422 * - deprecationLogger: Optional callback that takes a string and logs it.
423 * - cliMode: Whether to consider the execution context that of a CLI script.
424 * - agent: Optional name used to identify the end-user in query profiling/logging.
425 * - srvCache: Optional BagOStuff instance to an APC-style cache.
426 * - nonNativeInsertSelectBatchSize: Optional batch size for non-native INSERT SELECT emulation.
427 * @param int $connect One of the class constants (NEW_CONNECTED, NEW_UNCONNECTED) [optional]
428 * @return Database|null If the database driver or extension cannot be found
429 * @throws InvalidArgumentException If the database driver or extension cannot be found
430 * @since 1.18
431 */
432 final public static function factory( $dbType, $p = [], $connect = self::NEW_CONNECTED ) {
433 $class = self::getClass( $dbType, $p['driver'] ?? null );
434
435 if ( class_exists( $class ) && is_subclass_of( $class, IDatabase::class ) ) {
436 // Resolve some defaults for b/c
437 $p['host'] = $p['host'] ?? false;
438 $p['user'] = $p['user'] ?? false;
439 $p['password'] = $p['password'] ?? false;
440 $p['dbname'] = $p['dbname'] ?? false;
441 $p['flags'] = $p['flags'] ?? 0;
442 $p['variables'] = $p['variables'] ?? [];
443 $p['tablePrefix'] = $p['tablePrefix'] ?? '';
444 $p['schema'] = $p['schema'] ?? null;
445 $p['cliMode'] = $p['cliMode'] ?? ( PHP_SAPI === 'cli' || PHP_SAPI === 'phpdbg' );
446 $p['agent'] = $p['agent'] ?? '';
447 if ( !isset( $p['connLogger'] ) ) {
448 $p['connLogger'] = new NullLogger();
449 }
450 if ( !isset( $p['queryLogger'] ) ) {
451 $p['queryLogger'] = new NullLogger();
452 }
453 $p['profiler'] = $p['profiler'] ?? null;
454 if ( !isset( $p['trxProfiler'] ) ) {
455 $p['trxProfiler'] = new TransactionProfiler();
456 }
457 if ( !isset( $p['errorLogger'] ) ) {
458 $p['errorLogger'] = function ( Exception $e ) {
459 trigger_error( get_class( $e ) . ': ' . $e->getMessage(), E_USER_WARNING );
460 };
461 }
462 if ( !isset( $p['deprecationLogger'] ) ) {
463 $p['deprecationLogger'] = function ( $msg ) {
464 trigger_error( $msg, E_USER_DEPRECATED );
465 };
466 }
467
468 /** @var Database $conn */
469 $conn = new $class( $p );
470 if ( $connect == self::NEW_CONNECTED ) {
471 $conn->initConnection();
472 }
473 } else {
474 $conn = null;
475 }
476
477 return $conn;
478 }
479
480 /**
481 * @param string $dbType A possible DB type (sqlite, mysql, postgres,...)
482 * @param string|null $driver Optional name of a specific DB client driver
483 * @return array Map of (Database::ATTRIBUTE_* constant => value) for all such constants
484 * @throws InvalidArgumentException
485 * @since 1.31
486 */
487 final public static function attributesFromType( $dbType, $driver = null ) {
488 static $defaults = [ self::ATTR_DB_LEVEL_LOCKING => false ];
489
490 $class = self::getClass( $dbType, $driver );
491
492 return call_user_func( [ $class, 'getAttributes' ] ) + $defaults;
493 }
494
495 /**
496 * @param string $dbType A possible DB type (sqlite, mysql, postgres,...)
497 * @param string|null $driver Optional name of a specific DB client driver
498 * @return string Database subclass name to use
499 * @throws InvalidArgumentException
500 */
501 private static function getClass( $dbType, $driver = null ) {
502 // For database types with built-in support, the below maps type to IDatabase
503 // implementations. For types with multipe driver implementations (PHP extensions),
504 // an array can be used, keyed by extension name. In case of an array, the
505 // optional 'driver' parameter can be used to force a specific driver. Otherwise,
506 // we auto-detect the first available driver. For types without built-in support,
507 // an class named "Database<Type>" us used, eg. DatabaseFoo for type 'foo'.
508 static $builtinTypes = [
509 'mssql' => DatabaseMssql::class,
510 'mysql' => [ 'mysqli' => DatabaseMysqli::class ],
511 'sqlite' => DatabaseSqlite::class,
512 'postgres' => DatabasePostgres::class,
513 ];
514
515 $dbType = strtolower( $dbType );
516 $class = false;
517
518 if ( isset( $builtinTypes[$dbType] ) ) {
519 $possibleDrivers = $builtinTypes[$dbType];
520 if ( is_string( $possibleDrivers ) ) {
521 $class = $possibleDrivers;
522 } else {
523 if ( (string)$driver !== '' ) {
524 if ( !isset( $possibleDrivers[$driver] ) ) {
525 throw new InvalidArgumentException( __METHOD__ .
526 " type '$dbType' does not support driver '{$driver}'" );
527 } else {
528 $class = $possibleDrivers[$driver];
529 }
530 } else {
531 foreach ( $possibleDrivers as $posDriver => $possibleClass ) {
532 if ( extension_loaded( $posDriver ) ) {
533 $class = $possibleClass;
534 break;
535 }
536 }
537 }
538 }
539 } else {
540 $class = 'Database' . ucfirst( $dbType );
541 }
542
543 if ( $class === false ) {
544 throw new InvalidArgumentException( __METHOD__ .
545 " no viable database extension found for type '$dbType'" );
546 }
547
548 return $class;
549 }
550
551 /**
552 * @return array Map of (Database::ATTRIBUTE_* constant => value
553 * @since 1.31
554 */
555 protected static function getAttributes() {
556 return [];
557 }
558
559 /**
560 * Set the PSR-3 logger interface to use for query logging. (The logger
561 * interfaces for connection logging and error logging can be set with the
562 * constructor.)
563 *
564 * @param LoggerInterface $logger
565 */
566 public function setLogger( LoggerInterface $logger ) {
567 $this->queryLogger = $logger;
568 }
569
570 public function getServerInfo() {
571 return $this->getServerVersion();
572 }
573
574 public function bufferResults( $buffer = null ) {
575 $res = !$this->getFlag( self::DBO_NOBUFFER );
576 if ( $buffer !== null ) {
577 $buffer
578 ? $this->clearFlag( self::DBO_NOBUFFER )
579 : $this->setFlag( self::DBO_NOBUFFER );
580 }
581
582 return $res;
583 }
584
585 public function trxLevel() {
586 return $this->trxLevel;
587 }
588
589 public function trxTimestamp() {
590 return $this->trxLevel ? $this->trxTimestamp : null;
591 }
592
593 /**
594 * @return int One of the STATUS_TRX_* class constants
595 * @since 1.31
596 */
597 public function trxStatus() {
598 return $this->trxStatus;
599 }
600
601 public function tablePrefix( $prefix = null ) {
602 $old = $this->currentDomain->getTablePrefix();
603 if ( $prefix !== null ) {
604 $this->currentDomain = new DatabaseDomain(
605 $this->currentDomain->getDatabase(),
606 $this->currentDomain->getSchema(),
607 $prefix
608 );
609 }
610
611 return $old;
612 }
613
614 public function dbSchema( $schema = null ) {
615 $old = $this->currentDomain->getSchema();
616 if ( $schema !== null ) {
617 $this->currentDomain = new DatabaseDomain(
618 $this->currentDomain->getDatabase(),
619 // DatabaseDomain uses null for unspecified schemas
620 strlen( $schema ) ? $schema : null,
621 $this->currentDomain->getTablePrefix()
622 );
623 }
624
625 return (string)$old;
626 }
627
628 /**
629 * @return string Schema to use to qualify relations in queries
630 */
631 protected function relationSchemaQualifier() {
632 return $this->dbSchema();
633 }
634
635 public function getLBInfo( $name = null ) {
636 if ( is_null( $name ) ) {
637 return $this->lbInfo;
638 } else {
639 if ( array_key_exists( $name, $this->lbInfo ) ) {
640 return $this->lbInfo[$name];
641 } else {
642 return null;
643 }
644 }
645 }
646
647 public function setLBInfo( $name, $value = null ) {
648 if ( is_null( $value ) ) {
649 $this->lbInfo = $name;
650 } else {
651 $this->lbInfo[$name] = $value;
652 }
653 }
654
655 public function setLazyMasterHandle( IDatabase $conn ) {
656 $this->lazyMasterHandle = $conn;
657 }
658
659 /**
660 * @return IDatabase|null
661 * @see setLazyMasterHandle()
662 * @since 1.27
663 */
664 protected function getLazyMasterHandle() {
665 return $this->lazyMasterHandle;
666 }
667
668 public function implicitGroupby() {
669 return true;
670 }
671
672 public function implicitOrderby() {
673 return true;
674 }
675
676 public function lastQuery() {
677 return $this->lastQuery;
678 }
679
680 public function doneWrites() {
681 return (bool)$this->lastWriteTime;
682 }
683
684 public function lastDoneWrites() {
685 return $this->lastWriteTime ?: false;
686 }
687
688 public function writesPending() {
689 return $this->trxLevel && $this->trxDoneWrites;
690 }
691
692 public function writesOrCallbacksPending() {
693 return $this->trxLevel && (
694 $this->trxDoneWrites ||
695 $this->trxIdleCallbacks ||
696 $this->trxPreCommitCallbacks ||
697 $this->trxEndCallbacks
698 );
699 }
700
701 public function preCommitCallbacksPending() {
702 return $this->trxLevel && $this->trxPreCommitCallbacks;
703 }
704
705 /**
706 * @return string|null
707 */
708 final protected function getTransactionRoundId() {
709 // If transaction round participation is enabled, see if one is active
710 if ( $this->getFlag( self::DBO_TRX ) ) {
711 $id = $this->getLBInfo( 'trxRoundId' );
712
713 return is_string( $id ) ? $id : null;
714 }
715
716 return null;
717 }
718
719 public function pendingWriteQueryDuration( $type = self::ESTIMATE_TOTAL ) {
720 if ( !$this->trxLevel ) {
721 return false;
722 } elseif ( !$this->trxDoneWrites ) {
723 return 0.0;
724 }
725
726 switch ( $type ) {
727 case self::ESTIMATE_DB_APPLY:
728 return $this->pingAndCalculateLastTrxApplyTime();
729 default: // everything
730 return $this->trxWriteDuration;
731 }
732 }
733
734 /**
735 * @return float Time to apply writes to replicas based on trxWrite* fields
736 */
737 private function pingAndCalculateLastTrxApplyTime() {
738 $this->ping( $rtt );
739
740 $rttAdjTotal = $this->trxWriteAdjQueryCount * $rtt;
741 $applyTime = max( $this->trxWriteAdjDuration - $rttAdjTotal, 0 );
742 // For omitted queries, make them count as something at least
743 $omitted = $this->trxWriteQueryCount - $this->trxWriteAdjQueryCount;
744 $applyTime += self::TINY_WRITE_SEC * $omitted;
745
746 return $applyTime;
747 }
748
749 public function pendingWriteCallers() {
750 return $this->trxLevel ? $this->trxWriteCallers : [];
751 }
752
753 public function pendingWriteRowsAffected() {
754 return $this->trxWriteAffectedRows;
755 }
756
757 /**
758 * List the methods that have write queries or callbacks for the current transaction
759 *
760 * This method should not be used outside of Database/LoadBalancer
761 *
762 * @return string[]
763 * @since 1.32
764 */
765 public function pendingWriteAndCallbackCallers() {
766 $fnames = $this->pendingWriteCallers();
767 foreach ( [
768 $this->trxIdleCallbacks,
769 $this->trxPreCommitCallbacks,
770 $this->trxEndCallbacks
771 ] as $callbacks ) {
772 foreach ( $callbacks as $callback ) {
773 $fnames[] = $callback[1];
774 }
775 }
776
777 return $fnames;
778 }
779
780 /**
781 * @return string
782 */
783 private function flatAtomicSectionList() {
784 return array_reduce( $this->trxAtomicLevels, function ( $accum, $v ) {
785 return $accum === null ? $v[0] : "$accum, " . $v[0];
786 } );
787 }
788
789 public function isOpen() {
790 return $this->opened;
791 }
792
793 public function setFlag( $flag, $remember = self::REMEMBER_NOTHING ) {
794 if ( ( $flag & self::DBO_IGNORE ) ) {
795 throw new UnexpectedValueException( "Modifying DBO_IGNORE is not allowed." );
796 }
797
798 if ( $remember === self::REMEMBER_PRIOR ) {
799 array_push( $this->priorFlags, $this->flags );
800 }
801 $this->flags |= $flag;
802 }
803
804 public function clearFlag( $flag, $remember = self::REMEMBER_NOTHING ) {
805 if ( ( $flag & self::DBO_IGNORE ) ) {
806 throw new UnexpectedValueException( "Modifying DBO_IGNORE is not allowed." );
807 }
808
809 if ( $remember === self::REMEMBER_PRIOR ) {
810 array_push( $this->priorFlags, $this->flags );
811 }
812 $this->flags &= ~$flag;
813 }
814
815 public function restoreFlags( $state = self::RESTORE_PRIOR ) {
816 if ( !$this->priorFlags ) {
817 return;
818 }
819
820 if ( $state === self::RESTORE_INITIAL ) {
821 $this->flags = reset( $this->priorFlags );
822 $this->priorFlags = [];
823 } else {
824 $this->flags = array_pop( $this->priorFlags );
825 }
826 }
827
828 public function getFlag( $flag ) {
829 return (bool)( $this->flags & $flag );
830 }
831
832 /**
833 * @param string $name Class field name
834 * @return mixed
835 * @deprecated Since 1.28
836 */
837 public function getProperty( $name ) {
838 return $this->$name;
839 }
840
841 public function getDomainID() {
842 return $this->currentDomain->getId();
843 }
844
845 final public function getWikiID() {
846 return $this->getDomainID();
847 }
848
849 /**
850 * Get information about an index into an object
851 * @param string $table Table name
852 * @param string $index Index name
853 * @param string $fname Calling function name
854 * @return mixed Database-specific index description class or false if the index does not exist
855 */
856 abstract function indexInfo( $table, $index, $fname = __METHOD__ );
857
858 /**
859 * Wrapper for addslashes()
860 *
861 * @param string $s String to be slashed.
862 * @return string Slashed string.
863 */
864 abstract function strencode( $s );
865
866 /**
867 * Set a custom error handler for logging errors during database connection
868 */
869 protected function installErrorHandler() {
870 $this->phpError = false;
871 $this->htmlErrors = ini_set( 'html_errors', '0' );
872 set_error_handler( [ $this, 'connectionErrorLogger' ] );
873 }
874
875 /**
876 * Restore the previous error handler and return the last PHP error for this DB
877 *
878 * @return bool|string
879 */
880 protected function restoreErrorHandler() {
881 restore_error_handler();
882 if ( $this->htmlErrors !== false ) {
883 ini_set( 'html_errors', $this->htmlErrors );
884 }
885
886 return $this->getLastPHPError();
887 }
888
889 /**
890 * @return string|bool Last PHP error for this DB (typically connection errors)
891 */
892 protected function getLastPHPError() {
893 if ( $this->phpError ) {
894 $error = preg_replace( '!\[<a.*</a>\]!', '', $this->phpError );
895 $error = preg_replace( '!^.*?:\s?(.*)$!', '$1', $error );
896
897 return $error;
898 }
899
900 return false;
901 }
902
903 /**
904 * Error handler for logging errors during database connection
905 * This method should not be used outside of Database classes
906 *
907 * @param int $errno
908 * @param string $errstr
909 */
910 public function connectionErrorLogger( $errno, $errstr ) {
911 $this->phpError = $errstr;
912 }
913
914 /**
915 * Create a log context to pass to PSR-3 logger functions.
916 *
917 * @param array $extras Additional data to add to context
918 * @return array
919 */
920 protected function getLogContext( array $extras = [] ) {
921 return array_merge(
922 [
923 'db_server' => $this->server,
924 'db_name' => $this->getDBname(),
925 'db_user' => $this->user,
926 ],
927 $extras
928 );
929 }
930
931 final public function close() {
932 $exception = null; // error to throw after disconnecting
933
934 $wasOpen = $this->opened;
935 // This should mostly do nothing if the connection is already closed
936 if ( $this->conn ) {
937 // Roll back any dangling transaction first
938 if ( $this->trxLevel ) {
939 if ( $this->trxAtomicLevels ) {
940 // Cannot let incomplete atomic sections be committed
941 $levels = $this->flatAtomicSectionList();
942 $exception = new DBUnexpectedError(
943 $this,
944 __METHOD__ . ": atomic sections $levels are still open."
945 );
946 } elseif ( $this->trxAutomatic ) {
947 // Only the connection manager can commit non-empty DBO_TRX transactions
948 // (empty ones we can silently roll back)
949 if ( $this->writesOrCallbacksPending() ) {
950 $exception = new DBUnexpectedError(
951 $this,
952 __METHOD__ .
953 ": mass commit/rollback of peer transaction required (DBO_TRX set)."
954 );
955 }
956 } else {
957 // Manual transactions should have been committed or rolled
958 // back, even if empty.
959 $exception = new DBUnexpectedError(
960 $this,
961 __METHOD__ . ": transaction is still open (from {$this->trxFname})."
962 );
963 }
964
965 if ( $this->trxEndCallbacksSuppressed ) {
966 $exception = $exception ?: new DBUnexpectedError(
967 $this,
968 __METHOD__ . ': callbacks are suppressed; cannot properly commit.'
969 );
970 }
971
972 // Rollback the changes and run any callbacks as needed
973 $this->rollback( __METHOD__, self::FLUSHING_INTERNAL );
974 }
975
976 // Close the actual connection in the binding handle
977 $closed = $this->closeConnection();
978 } else {
979 $closed = true; // already closed; nothing to do
980 }
981
982 $this->conn = false;
983 $this->opened = false;
984
985 // Throw any unexpected errors after having disconnected
986 if ( $exception instanceof Exception ) {
987 throw $exception;
988 }
989
990 // Note that various subclasses call close() at the start of open(), which itself is
991 // called by replaceLostConnection(). In that case, just because onTransactionResolution()
992 // callbacks are pending does not mean that an exception should be thrown. Rather, they
993 // will be executed after the reconnection step.
994 if ( $wasOpen ) {
995 // Sanity check that no callbacks are dangling
996 $fnames = $this->pendingWriteAndCallbackCallers();
997 if ( $fnames ) {
998 throw new RuntimeException(
999 "Transaction callbacks are still pending:\n" . implode( ', ', $fnames )
1000 );
1001 }
1002 }
1003
1004 return $closed;
1005 }
1006
1007 /**
1008 * Make sure there is an open connection handle (alive or not) as a sanity check
1009 *
1010 * This guards against fatal errors to the binding handle not being defined
1011 * in cases where open() was never called or close() was already called
1012 *
1013 * @throws DBUnexpectedError
1014 */
1015 protected function assertHasConnectionHandle() {
1016 if ( !$this->isOpen() ) {
1017 throw new DBUnexpectedError( $this, "DB connection was already closed." );
1018 }
1019 }
1020
1021 /**
1022 * Make sure that this server is not marked as a replica nor read-only as a sanity check
1023 *
1024 * @throws DBUnexpectedError
1025 */
1026 protected function assertIsWritableMaster() {
1027 if ( $this->getLBInfo( 'replica' ) === true ) {
1028 throw new DBUnexpectedError(
1029 $this,
1030 'Write operations are not allowed on replica database connections.'
1031 );
1032 }
1033 $reason = $this->getReadOnlyReason();
1034 if ( $reason !== false ) {
1035 throw new DBReadOnlyError( $this, "Database is read-only: $reason" );
1036 }
1037 }
1038
1039 /**
1040 * Closes underlying database connection
1041 * @since 1.20
1042 * @return bool Whether connection was closed successfully
1043 */
1044 abstract protected function closeConnection();
1045
1046 /**
1047 * @deprecated since 1.32
1048 * @param string $error Fallback message, if none is given by DB
1049 * @throws DBConnectionError
1050 */
1051 public function reportConnectionError( $error = 'Unknown error' ) {
1052 call_user_func( $this->deprecationLogger, 'Use of ' . __METHOD__ . ' is deprecated.' );
1053 throw new DBConnectionError( $this, $this->lastError() ?: $error );
1054 }
1055
1056 /**
1057 * Run a query and return a DBMS-dependent wrapper or boolean
1058 *
1059 * For SELECT queries, this returns either:
1060 * - a) A driver-specific value/resource, only on success. This can be iterated
1061 * over by calling fetchObject()/fetchRow() until there are no more rows.
1062 * Alternatively, the result can be passed to resultObject() to obtain a
1063 * ResultWrapper instance which can then be iterated over via "foreach".
1064 * - b) False, on any query failure
1065 *
1066 * For non-SELECT queries, this returns either:
1067 * - a) A driver-specific value/resource, only on success
1068 * - b) True, only on success (e.g. no meaningful result other than "OK")
1069 * - c) False, on any query failure
1070 *
1071 * @param string $sql SQL query
1072 * @return mixed|bool An object, resource, or true on success; false on failure
1073 */
1074 abstract protected function doQuery( $sql );
1075
1076 /**
1077 * Determine whether a query writes to the DB. When in doubt, this returns true.
1078 *
1079 * Main use cases:
1080 *
1081 * - Subsequent web requests should not need to wait for replication from
1082 * the master position seen by this web request, unless this request made
1083 * changes to the master. This is handled by ChronologyProtector by checking
1084 * doneWrites() at the end of the request. doneWrites() returns true if any
1085 * query set lastWriteTime; which query() does based on isWriteQuery().
1086 *
1087 * - Reject write queries to replica DBs, in query().
1088 *
1089 * @param string $sql
1090 * @return bool
1091 */
1092 protected function isWriteQuery( $sql ) {
1093 // BEGIN and COMMIT queries are considered read queries here.
1094 // Database backends and drivers (MySQL, MariaDB, php-mysqli) generally
1095 // treat these as write queries, in that their results have "affected rows"
1096 // as meta data as from writes, instead of "num rows" as from reads.
1097 // But, we treat them as read queries because when reading data (from
1098 // either replica or master) we use transactions to enable repeatable-read
1099 // snapshots, which ensures we get consistent results from the same snapshot
1100 // for all queries within a request. Use cases:
1101 // - Treating these as writes would trigger ChronologyProtector (see method doc).
1102 // - We use this method to reject writes to replicas, but we need to allow
1103 // use of transactions on replicas for read snapshots. This fine given
1104 // that transactions by themselves don't make changes, only actual writes
1105 // within the transaction matter, which we still detect.
1106 return !preg_match(
1107 '/^(?:SELECT|BEGIN|ROLLBACK|COMMIT|SAVEPOINT|RELEASE|SET|SHOW|EXPLAIN|\(SELECT)\b/i',
1108 $sql
1109 );
1110 }
1111
1112 /**
1113 * @param string $sql
1114 * @return string|null
1115 */
1116 protected function getQueryVerb( $sql ) {
1117 return preg_match( '/^\s*([a-z]+)/i', $sql, $m ) ? strtoupper( $m[1] ) : null;
1118 }
1119
1120 /**
1121 * Determine whether a SQL statement is sensitive to isolation level.
1122 *
1123 * A SQL statement is considered transactable if its result could vary
1124 * depending on the transaction isolation level. Operational commands
1125 * such as 'SET' and 'SHOW' are not considered to be transactable.
1126 *
1127 * Main purpose: Used by query() to decide whether to begin a transaction
1128 * before the current query (in DBO_TRX mode, on by default).
1129 *
1130 * @param string $sql
1131 * @return bool
1132 */
1133 protected function isTransactableQuery( $sql ) {
1134 return !in_array(
1135 $this->getQueryVerb( $sql ),
1136 [ 'BEGIN', 'ROLLBACK', 'COMMIT', 'SET', 'SHOW', 'CREATE', 'ALTER' ],
1137 true
1138 );
1139 }
1140
1141 /**
1142 * @param string $sql A SQL query
1143 * @param bool $pseudoPermanent Treat any table from CREATE TEMPORARY as pseudo-permanent
1144 * @return int|null A self::TEMP_* constant for temp table operations or null otherwise
1145 */
1146 protected function registerTempTableWrite( $sql, $pseudoPermanent ) {
1147 static $qt = '[`"\']?(\w+)[`"\']?'; // quoted table
1148
1149 if ( preg_match(
1150 '/^CREATE\s+TEMPORARY\s+TABLE\s+(?:IF\s+NOT\s+EXISTS\s+)?' . $qt . '/i',
1151 $sql,
1152 $matches
1153 ) ) {
1154 $type = $pseudoPermanent ? self::TEMP_PSEUDO_PERMANENT : self::TEMP_NORMAL;
1155 $this->sessionTempTables[$matches[1]] = $type;
1156
1157 return $type;
1158 } elseif ( preg_match(
1159 '/^DROP\s+(?:TEMPORARY\s+)?TABLE\s+(?:IF\s+EXISTS\s+)?' . $qt . '/i',
1160 $sql,
1161 $matches
1162 ) ) {
1163 $type = $this->sessionTempTables[$matches[1]] ?? null;
1164 unset( $this->sessionTempTables[$matches[1]] );
1165
1166 return $type;
1167 } elseif ( preg_match(
1168 '/^TRUNCATE\s+(?:TEMPORARY\s+)?TABLE\s+(?:IF\s+EXISTS\s+)?' . $qt . '/i',
1169 $sql,
1170 $matches
1171 ) ) {
1172 return $this->sessionTempTables[$matches[1]] ?? null;
1173 } elseif ( preg_match(
1174 '/^(?:(?:INSERT|REPLACE)\s+(?:\w+\s+)?INTO|UPDATE|DELETE\s+FROM)\s+' . $qt . '/i',
1175 $sql,
1176 $matches
1177 ) ) {
1178 return $this->sessionTempTables[$matches[1]] ?? null;
1179 }
1180
1181 return null;
1182 }
1183
1184 public function query( $sql, $fname = __METHOD__, $flags = 0 ) {
1185 $this->assertTransactionStatus( $sql, $fname );
1186 $this->assertHasConnectionHandle();
1187
1188 $flags = (int)$flags; // b/c; this field used to be a bool
1189 $ignoreErrors = $this->hasFlags( $flags, self::QUERY_SILENCE_ERRORS );
1190 $pseudoPermanent = $this->hasFlags( $flags, self::QUERY_PSEUDO_PERMANENT );
1191
1192 $priorTransaction = $this->trxLevel;
1193 $priorWritesPending = $this->writesOrCallbacksPending();
1194 $this->lastQuery = $sql;
1195
1196 if ( $this->isWriteQuery( $sql ) ) {
1197 # In theory, non-persistent writes are allowed in read-only mode, but due to things
1198 # like https://bugs.mysql.com/bug.php?id=33669 that might not work anyway...
1199 $this->assertIsWritableMaster();
1200 # Do not treat temporary table writes as "meaningful writes" that need committing.
1201 # Profile them as reads. Integration tests can override this behavior via $flags.
1202 $tableType = $this->registerTempTableWrite( $sql, $pseudoPermanent );
1203 $isEffectiveWrite = ( $tableType !== self::TEMP_NORMAL );
1204 } else {
1205 $isEffectiveWrite = false;
1206 }
1207
1208 # Add trace comment to the begin of the sql string, right after the operator.
1209 # Or, for one-word queries (like "BEGIN" or COMMIT") add it to the end (T44598)
1210 $commentedSql = preg_replace( '/\s|$/', " /* $fname {$this->agent} */ ", $sql, 1 );
1211
1212 # Send the query to the server and fetch any corresponding errors
1213 $ret = $this->attemptQuery( $sql, $commentedSql, $isEffectiveWrite, $fname );
1214 $lastError = $this->lastError();
1215 $lastErrno = $this->lastErrno();
1216
1217 $recoverableSR = false; // recoverable statement rollback?
1218 $recoverableCL = false; // recoverable connection loss?
1219
1220 if ( $ret === false && $this->wasConnectionLoss() ) {
1221 # Check if no meaningful session state was lost
1222 $recoverableCL = $this->canRecoverFromDisconnect( $sql, $priorWritesPending );
1223 # Update session state tracking and try to restore the connection
1224 $reconnected = $this->replaceLostConnection( __METHOD__ );
1225 # Silently resend the query to the server if it is safe and possible
1226 if ( $recoverableCL && $reconnected ) {
1227 $ret = $this->attemptQuery( $sql, $commentedSql, $isEffectiveWrite, $fname );
1228 $lastError = $this->lastError();
1229 $lastErrno = $this->lastErrno();
1230
1231 if ( $ret === false && $this->wasConnectionLoss() ) {
1232 # Query probably causes disconnects; reconnect and do not re-run it
1233 $this->replaceLostConnection( __METHOD__ );
1234 } else {
1235 $recoverableCL = false; // connection does not need recovering
1236 $recoverableSR = $this->wasKnownStatementRollbackError();
1237 }
1238 }
1239 } else {
1240 $recoverableSR = $this->wasKnownStatementRollbackError();
1241 }
1242
1243 if ( $ret === false ) {
1244 if ( $priorTransaction ) {
1245 if ( $recoverableSR ) {
1246 # We're ignoring an error that caused just the current query to be aborted.
1247 # But log the cause so we can log a deprecation notice if a caller actually
1248 # does ignore it.
1249 $this->trxStatusIgnoredCause = [ $lastError, $lastErrno, $fname ];
1250 } elseif ( !$recoverableCL ) {
1251 # Either the query was aborted or all queries after BEGIN where aborted.
1252 # In the first case, the only options going forward are (a) ROLLBACK, or
1253 # (b) ROLLBACK TO SAVEPOINT (if one was set). If the later case, the only
1254 # option is ROLLBACK, since the snapshots would have been released.
1255 $this->trxStatus = self::STATUS_TRX_ERROR;
1256 $this->trxStatusCause =
1257 $this->getQueryExceptionAndLog( $lastError, $lastErrno, $sql, $fname );
1258 $ignoreErrors = false; // cannot recover
1259 $this->trxStatusIgnoredCause = null;
1260 }
1261 }
1262
1263 $this->reportQueryError( $lastError, $lastErrno, $sql, $fname, $ignoreErrors );
1264 }
1265
1266 return $this->resultObject( $ret );
1267 }
1268
1269 /**
1270 * Wrapper for query() that also handles profiling, logging, and affected row count updates
1271 *
1272 * @param string $sql Original SQL query
1273 * @param string $commentedSql SQL query with debugging/trace comment
1274 * @param bool $isEffectiveWrite Whether the query is a (non-temporary table) write
1275 * @param string $fname Name of the calling function
1276 * @return bool|ResultWrapper True for a successful write query, ResultWrapper
1277 * object for a successful read query, or false on failure
1278 */
1279 private function attemptQuery( $sql, $commentedSql, $isEffectiveWrite, $fname ) {
1280 $this->beginIfImplied( $sql, $fname );
1281
1282 # Keep track of whether the transaction has write queries pending
1283 if ( $isEffectiveWrite ) {
1284 $this->lastWriteTime = microtime( true );
1285 if ( $this->trxLevel && !$this->trxDoneWrites ) {
1286 $this->trxDoneWrites = true;
1287 $this->trxProfiler->transactionWritingIn(
1288 $this->server, $this->getDomainID(), $this->trxShortId );
1289 }
1290 }
1291
1292 if ( $this->getFlag( self::DBO_DEBUG ) ) {
1293 $this->queryLogger->debug( "{$this->getDomainID()} {$commentedSql}" );
1294 }
1295
1296 $isMaster = !is_null( $this->getLBInfo( 'master' ) );
1297 # generalizeSQL() will probably cut down the query to reasonable
1298 # logging size most of the time. The substr is really just a sanity check.
1299 if ( $isMaster ) {
1300 $queryProf = 'query-m: ' . substr( self::generalizeSQL( $sql ), 0, 255 );
1301 } else {
1302 $queryProf = 'query: ' . substr( self::generalizeSQL( $sql ), 0, 255 );
1303 }
1304
1305 # Include query transaction state
1306 $queryProf .= $this->trxShortId ? " [TRX#{$this->trxShortId}]" : "";
1307
1308 $startTime = microtime( true );
1309 $ps = $this->profiler ? ( $this->profiler )( $queryProf ) : null;
1310 $this->affectedRowCount = null;
1311 $ret = $this->doQuery( $commentedSql );
1312 $this->affectedRowCount = $this->affectedRows();
1313 unset( $ps ); // profile out (if set)
1314 $queryRuntime = max( microtime( true ) - $startTime, 0.0 );
1315
1316 if ( $ret !== false ) {
1317 $this->lastPing = $startTime;
1318 if ( $isEffectiveWrite && $this->trxLevel ) {
1319 $this->updateTrxWriteQueryTime( $sql, $queryRuntime, $this->affectedRows() );
1320 $this->trxWriteCallers[] = $fname;
1321 }
1322 }
1323
1324 if ( $sql === self::PING_QUERY ) {
1325 $this->rttEstimate = $queryRuntime;
1326 }
1327
1328 $this->trxProfiler->recordQueryCompletion(
1329 $queryProf,
1330 $startTime,
1331 $isEffectiveWrite,
1332 $isEffectiveWrite ? $this->affectedRows() : $this->numRows( $ret )
1333 );
1334 $this->queryLogger->debug( $sql, [
1335 'method' => $fname,
1336 'master' => $isMaster,
1337 'runtime' => $queryRuntime,
1338 ] );
1339
1340 return $ret;
1341 }
1342
1343 /**
1344 * Start an implicit transaction if DBO_TRX is enabled and no transaction is active
1345 *
1346 * @param string $sql
1347 * @param string $fname
1348 */
1349 private function beginIfImplied( $sql, $fname ) {
1350 if (
1351 !$this->trxLevel &&
1352 $this->getFlag( self::DBO_TRX ) &&
1353 $this->isTransactableQuery( $sql )
1354 ) {
1355 $this->begin( __METHOD__ . " ($fname)", self::TRANSACTION_INTERNAL );
1356 $this->trxAutomatic = true;
1357 }
1358 }
1359
1360 /**
1361 * Update the estimated run-time of a query, not counting large row lock times
1362 *
1363 * LoadBalancer can be set to rollback transactions that will create huge replication
1364 * lag. It bases this estimate off of pendingWriteQueryDuration(). Certain simple
1365 * queries, like inserting a row can take a long time due to row locking. This method
1366 * uses some simple heuristics to discount those cases.
1367 *
1368 * @param string $sql A SQL write query
1369 * @param float $runtime Total runtime, including RTT
1370 * @param int $affected Affected row count
1371 */
1372 private function updateTrxWriteQueryTime( $sql, $runtime, $affected ) {
1373 // Whether this is indicative of replica DB runtime (except for RBR or ws_repl)
1374 $indicativeOfReplicaRuntime = true;
1375 if ( $runtime > self::SLOW_WRITE_SEC ) {
1376 $verb = $this->getQueryVerb( $sql );
1377 // insert(), upsert(), replace() are fast unless bulky in size or blocked on locks
1378 if ( $verb === 'INSERT' ) {
1379 $indicativeOfReplicaRuntime = $this->affectedRows() > self::SMALL_WRITE_ROWS;
1380 } elseif ( $verb === 'REPLACE' ) {
1381 $indicativeOfReplicaRuntime = $this->affectedRows() > self::SMALL_WRITE_ROWS / 2;
1382 }
1383 }
1384
1385 $this->trxWriteDuration += $runtime;
1386 $this->trxWriteQueryCount += 1;
1387 $this->trxWriteAffectedRows += $affected;
1388 if ( $indicativeOfReplicaRuntime ) {
1389 $this->trxWriteAdjDuration += $runtime;
1390 $this->trxWriteAdjQueryCount += 1;
1391 }
1392 }
1393
1394 /**
1395 * Error out if the DB is not in a valid state for a query via query()
1396 *
1397 * @param string $sql
1398 * @param string $fname
1399 * @throws DBTransactionStateError
1400 */
1401 private function assertTransactionStatus( $sql, $fname ) {
1402 $verb = $this->getQueryVerb( $sql );
1403 if ( $verb === 'USE' ) {
1404 throw new DBUnexpectedError( $this, "Got USE query; use selectDomain() instead." );
1405 }
1406
1407 if ( $verb === 'ROLLBACK' ) { // transaction/savepoint
1408 return;
1409 }
1410
1411 if ( $this->trxStatus < self::STATUS_TRX_OK ) {
1412 throw new DBTransactionStateError(
1413 $this,
1414 "Cannot execute query from $fname while transaction status is ERROR.",
1415 [],
1416 $this->trxStatusCause
1417 );
1418 } elseif ( $this->trxStatus === self::STATUS_TRX_OK && $this->trxStatusIgnoredCause ) {
1419 list( $iLastError, $iLastErrno, $iFname ) = $this->trxStatusIgnoredCause;
1420 call_user_func( $this->deprecationLogger,
1421 "Caller from $fname ignored an error originally raised from $iFname: " .
1422 "[$iLastErrno] $iLastError"
1423 );
1424 $this->trxStatusIgnoredCause = null;
1425 }
1426 }
1427
1428 public function assertNoOpenTransactions() {
1429 if ( $this->explicitTrxActive() ) {
1430 throw new DBTransactionError(
1431 $this,
1432 "Explicit transaction still active. A caller may have caught an error. "
1433 . "Open transactions: " . $this->flatAtomicSectionList()
1434 );
1435 }
1436 }
1437
1438 /**
1439 * Determine whether it is safe to retry queries after a database connection is lost
1440 *
1441 * @param string $sql SQL query
1442 * @param bool $priorWritesPending Whether there is a transaction open with
1443 * possible write queries or transaction pre-commit/idle callbacks
1444 * waiting on it to finish.
1445 * @return bool True if it is safe to retry the query, false otherwise
1446 */
1447 private function canRecoverFromDisconnect( $sql, $priorWritesPending ) {
1448 # Transaction dropped; this can mean lost writes, or REPEATABLE-READ snapshots.
1449 # Dropped connections also mean that named locks are automatically released.
1450 # Only allow error suppression in autocommit mode or when the lost transaction
1451 # didn't matter anyway (aside from DBO_TRX snapshot loss).
1452 if ( $this->namedLocksHeld ) {
1453 return false; // possible critical section violation
1454 } elseif ( $this->sessionTempTables ) {
1455 return false; // tables might be queried latter
1456 } elseif ( $sql === 'COMMIT' ) {
1457 return !$priorWritesPending; // nothing written anyway? (T127428)
1458 } elseif ( $sql === 'ROLLBACK' ) {
1459 return true; // transaction lost...which is also what was requested :)
1460 } elseif ( $this->explicitTrxActive() ) {
1461 return false; // don't drop atomocity and explicit snapshots
1462 } elseif ( $priorWritesPending ) {
1463 return false; // prior writes lost from implicit transaction
1464 }
1465
1466 return true;
1467 }
1468
1469 /**
1470 * Clean things up after session (and thus transaction) loss before reconnect
1471 */
1472 private function handleSessionLossPreconnect() {
1473 // Clean up tracking of session-level things...
1474 // https://dev.mysql.com/doc/refman/5.7/en/implicit-commit.html
1475 // https://www.postgresql.org/docs/9.2/static/sql-createtable.html (ignoring ON COMMIT)
1476 $this->sessionTempTables = [];
1477 // https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_get-lock
1478 // https://www.postgresql.org/docs/9.4/static/functions-admin.html#FUNCTIONS-ADVISORY-LOCKS
1479 $this->namedLocksHeld = [];
1480 // Session loss implies transaction loss
1481 $this->trxLevel = 0;
1482 $this->trxAtomicCounter = 0;
1483 $this->trxIdleCallbacks = []; // T67263; transaction already lost
1484 $this->trxPreCommitCallbacks = []; // T67263; transaction already lost
1485 // @note: leave trxRecurringCallbacks in place
1486 if ( $this->trxDoneWrites ) {
1487 $this->trxProfiler->transactionWritingOut(
1488 $this->server,
1489 $this->getDomainID(),
1490 $this->trxShortId,
1491 $this->pendingWriteQueryDuration( self::ESTIMATE_TOTAL ),
1492 $this->trxWriteAffectedRows
1493 );
1494 }
1495 }
1496
1497 /**
1498 * Clean things up after session (and thus transaction) loss after reconnect
1499 */
1500 private function handleSessionLossPostconnect() {
1501 try {
1502 // Handle callbacks in trxEndCallbacks, e.g. onTransactionResolution().
1503 // If callback suppression is set then the array will remain unhandled.
1504 $this->runOnTransactionIdleCallbacks( self::TRIGGER_ROLLBACK );
1505 } catch ( Exception $ex ) {
1506 // Already logged; move on...
1507 }
1508 try {
1509 // Handle callbacks in trxRecurringCallbacks, e.g. setTransactionListener()
1510 $this->runTransactionListenerCallbacks( self::TRIGGER_ROLLBACK );
1511 } catch ( Exception $ex ) {
1512 // Already logged; move on...
1513 }
1514 }
1515
1516 /**
1517 * Checks whether the cause of the error is detected to be a timeout.
1518 *
1519 * It returns false by default, and not all engines support detecting this yet.
1520 * If this returns false, it will be treated as a generic query error.
1521 *
1522 * @param string $error Error text
1523 * @param int $errno Error number
1524 * @return bool
1525 */
1526 protected function wasQueryTimeout( $error, $errno ) {
1527 return false;
1528 }
1529
1530 /**
1531 * Report a query error. Log the error, and if neither the object ignore
1532 * flag nor the $ignoreErrors flag is set, throw a DBQueryError.
1533 *
1534 * @param string $error
1535 * @param int $errno
1536 * @param string $sql
1537 * @param string $fname
1538 * @param bool $ignoreErrors
1539 * @throws DBQueryError
1540 */
1541 public function reportQueryError( $error, $errno, $sql, $fname, $ignoreErrors = false ) {
1542 if ( $ignoreErrors ) {
1543 $this->queryLogger->debug( "SQL ERROR (ignored): $error\n" );
1544 } else {
1545 $exception = $this->getQueryExceptionAndLog( $error, $errno, $sql, $fname );
1546
1547 throw $exception;
1548 }
1549 }
1550
1551 /**
1552 * @param string $error
1553 * @param string|int $errno
1554 * @param string $sql
1555 * @param string $fname
1556 * @return DBError
1557 */
1558 private function getQueryExceptionAndLog( $error, $errno, $sql, $fname ) {
1559 $sql1line = mb_substr( str_replace( "\n", "\\n", $sql ), 0, 5 * 1024 );
1560 $this->queryLogger->error(
1561 "{fname}\t{db_server}\t{errno}\t{error}\t{sql1line}",
1562 $this->getLogContext( [
1563 'method' => __METHOD__,
1564 'errno' => $errno,
1565 'error' => $error,
1566 'sql1line' => $sql1line,
1567 'fname' => $fname,
1568 'trace' => ( new RuntimeException() )->getTraceAsString()
1569 ] )
1570 );
1571 $this->queryLogger->debug( "SQL ERROR: " . $error . "\n" );
1572 $wasQueryTimeout = $this->wasQueryTimeout( $error, $errno );
1573 if ( $wasQueryTimeout ) {
1574 $e = new DBQueryTimeoutError( $this, $error, $errno, $sql, $fname );
1575 } else {
1576 $e = new DBQueryError( $this, $error, $errno, $sql, $fname );
1577 }
1578
1579 return $e;
1580 }
1581
1582 public function freeResult( $res ) {
1583 }
1584
1585 public function selectField(
1586 $table, $var, $cond = '', $fname = __METHOD__, $options = [], $join_conds = []
1587 ) {
1588 if ( $var === '*' ) { // sanity
1589 throw new DBUnexpectedError( $this, "Cannot use a * field: got '$var'" );
1590 }
1591
1592 if ( !is_array( $options ) ) {
1593 $options = [ $options ];
1594 }
1595
1596 $options['LIMIT'] = 1;
1597
1598 $res = $this->select( $table, $var, $cond, $fname, $options, $join_conds );
1599 if ( $res === false || !$this->numRows( $res ) ) {
1600 return false;
1601 }
1602
1603 $row = $this->fetchRow( $res );
1604
1605 if ( $row !== false ) {
1606 return reset( $row );
1607 } else {
1608 return false;
1609 }
1610 }
1611
1612 public function selectFieldValues(
1613 $table, $var, $cond = '', $fname = __METHOD__, $options = [], $join_conds = []
1614 ) {
1615 if ( $var === '*' ) { // sanity
1616 throw new DBUnexpectedError( $this, "Cannot use a * field" );
1617 } elseif ( !is_string( $var ) ) { // sanity
1618 throw new DBUnexpectedError( $this, "Cannot use an array of fields" );
1619 }
1620
1621 if ( !is_array( $options ) ) {
1622 $options = [ $options ];
1623 }
1624
1625 $res = $this->select( $table, [ 'value' => $var ], $cond, $fname, $options, $join_conds );
1626 if ( $res === false ) {
1627 return false;
1628 }
1629
1630 $values = [];
1631 foreach ( $res as $row ) {
1632 $values[] = $row->value;
1633 }
1634
1635 return $values;
1636 }
1637
1638 /**
1639 * Returns an optional USE INDEX clause to go after the table, and a
1640 * string to go at the end of the query.
1641 *
1642 * @param array $options Associative array of options to be turned into
1643 * an SQL query, valid keys are listed in the function.
1644 * @return array
1645 * @see Database::select()
1646 */
1647 protected function makeSelectOptions( $options ) {
1648 $preLimitTail = $postLimitTail = '';
1649 $startOpts = '';
1650
1651 $noKeyOptions = [];
1652
1653 foreach ( $options as $key => $option ) {
1654 if ( is_numeric( $key ) ) {
1655 $noKeyOptions[$option] = true;
1656 }
1657 }
1658
1659 $preLimitTail .= $this->makeGroupByWithHaving( $options );
1660
1661 $preLimitTail .= $this->makeOrderBy( $options );
1662
1663 if ( isset( $noKeyOptions['FOR UPDATE'] ) ) {
1664 $postLimitTail .= ' FOR UPDATE';
1665 }
1666
1667 if ( isset( $noKeyOptions['LOCK IN SHARE MODE'] ) ) {
1668 $postLimitTail .= ' LOCK IN SHARE MODE';
1669 }
1670
1671 if ( isset( $noKeyOptions['DISTINCT'] ) || isset( $noKeyOptions['DISTINCTROW'] ) ) {
1672 $startOpts .= 'DISTINCT';
1673 }
1674
1675 # Various MySQL extensions
1676 if ( isset( $noKeyOptions['STRAIGHT_JOIN'] ) ) {
1677 $startOpts .= ' /*! STRAIGHT_JOIN */';
1678 }
1679
1680 if ( isset( $noKeyOptions['HIGH_PRIORITY'] ) ) {
1681 $startOpts .= ' HIGH_PRIORITY';
1682 }
1683
1684 if ( isset( $noKeyOptions['SQL_BIG_RESULT'] ) ) {
1685 $startOpts .= ' SQL_BIG_RESULT';
1686 }
1687
1688 if ( isset( $noKeyOptions['SQL_BUFFER_RESULT'] ) ) {
1689 $startOpts .= ' SQL_BUFFER_RESULT';
1690 }
1691
1692 if ( isset( $noKeyOptions['SQL_SMALL_RESULT'] ) ) {
1693 $startOpts .= ' SQL_SMALL_RESULT';
1694 }
1695
1696 if ( isset( $noKeyOptions['SQL_CALC_FOUND_ROWS'] ) ) {
1697 $startOpts .= ' SQL_CALC_FOUND_ROWS';
1698 }
1699
1700 if ( isset( $noKeyOptions['SQL_CACHE'] ) ) {
1701 $startOpts .= ' SQL_CACHE';
1702 }
1703
1704 if ( isset( $noKeyOptions['SQL_NO_CACHE'] ) ) {
1705 $startOpts .= ' SQL_NO_CACHE';
1706 }
1707
1708 if ( isset( $options['USE INDEX'] ) && is_string( $options['USE INDEX'] ) ) {
1709 $useIndex = $this->useIndexClause( $options['USE INDEX'] );
1710 } else {
1711 $useIndex = '';
1712 }
1713 if ( isset( $options['IGNORE INDEX'] ) && is_string( $options['IGNORE INDEX'] ) ) {
1714 $ignoreIndex = $this->ignoreIndexClause( $options['IGNORE INDEX'] );
1715 } else {
1716 $ignoreIndex = '';
1717 }
1718
1719 return [ $startOpts, $useIndex, $preLimitTail, $postLimitTail, $ignoreIndex ];
1720 }
1721
1722 /**
1723 * Returns an optional GROUP BY with an optional HAVING
1724 *
1725 * @param array $options Associative array of options
1726 * @return string
1727 * @see Database::select()
1728 * @since 1.21
1729 */
1730 protected function makeGroupByWithHaving( $options ) {
1731 $sql = '';
1732 if ( isset( $options['GROUP BY'] ) ) {
1733 $gb = is_array( $options['GROUP BY'] )
1734 ? implode( ',', $options['GROUP BY'] )
1735 : $options['GROUP BY'];
1736 $sql .= ' GROUP BY ' . $gb;
1737 }
1738 if ( isset( $options['HAVING'] ) ) {
1739 $having = is_array( $options['HAVING'] )
1740 ? $this->makeList( $options['HAVING'], self::LIST_AND )
1741 : $options['HAVING'];
1742 $sql .= ' HAVING ' . $having;
1743 }
1744
1745 return $sql;
1746 }
1747
1748 /**
1749 * Returns an optional ORDER BY
1750 *
1751 * @param array $options Associative array of options
1752 * @return string
1753 * @see Database::select()
1754 * @since 1.21
1755 */
1756 protected function makeOrderBy( $options ) {
1757 if ( isset( $options['ORDER BY'] ) ) {
1758 $ob = is_array( $options['ORDER BY'] )
1759 ? implode( ',', $options['ORDER BY'] )
1760 : $options['ORDER BY'];
1761
1762 return ' ORDER BY ' . $ob;
1763 }
1764
1765 return '';
1766 }
1767
1768 public function select(
1769 $table, $vars, $conds = '', $fname = __METHOD__, $options = [], $join_conds = []
1770 ) {
1771 $sql = $this->selectSQLText( $table, $vars, $conds, $fname, $options, $join_conds );
1772
1773 return $this->query( $sql, $fname );
1774 }
1775
1776 public function selectSQLText( $table, $vars, $conds = '', $fname = __METHOD__,
1777 $options = [], $join_conds = []
1778 ) {
1779 if ( is_array( $vars ) ) {
1780 $fields = implode( ',', $this->fieldNamesWithAlias( $vars ) );
1781 } else {
1782 $fields = $vars;
1783 }
1784
1785 $options = (array)$options;
1786 $useIndexes = ( isset( $options['USE INDEX'] ) && is_array( $options['USE INDEX'] ) )
1787 ? $options['USE INDEX']
1788 : [];
1789 $ignoreIndexes = (
1790 isset( $options['IGNORE INDEX'] ) &&
1791 is_array( $options['IGNORE INDEX'] )
1792 )
1793 ? $options['IGNORE INDEX']
1794 : [];
1795
1796 if (
1797 $this->selectOptionsIncludeLocking( $options ) &&
1798 $this->selectFieldsOrOptionsAggregate( $vars, $options )
1799 ) {
1800 // Some DB types (postgres/oracle) disallow FOR UPDATE with aggregate
1801 // functions. Discourage use of such queries to encourage compatibility.
1802 call_user_func(
1803 $this->deprecationLogger,
1804 __METHOD__ . ": aggregation used with a locking SELECT ($fname)."
1805 );
1806 }
1807
1808 if ( is_array( $table ) ) {
1809 $from = ' FROM ' .
1810 $this->tableNamesWithIndexClauseOrJOIN(
1811 $table, $useIndexes, $ignoreIndexes, $join_conds );
1812 } elseif ( $table != '' ) {
1813 $from = ' FROM ' .
1814 $this->tableNamesWithIndexClauseOrJOIN(
1815 [ $table ], $useIndexes, $ignoreIndexes, [] );
1816 } else {
1817 $from = '';
1818 }
1819
1820 list( $startOpts, $useIndex, $preLimitTail, $postLimitTail, $ignoreIndex ) =
1821 $this->makeSelectOptions( $options );
1822
1823 if ( is_array( $conds ) ) {
1824 $conds = $this->makeList( $conds, self::LIST_AND );
1825 }
1826
1827 if ( $conds === null || $conds === false ) {
1828 $this->queryLogger->warning(
1829 __METHOD__
1830 . ' called from '
1831 . $fname
1832 . ' with incorrect parameters: $conds must be a string or an array'
1833 );
1834 $conds = '';
1835 }
1836
1837 if ( $conds === '' || $conds === '*' ) {
1838 $sql = "SELECT $startOpts $fields $from $useIndex $ignoreIndex $preLimitTail";
1839 } elseif ( is_string( $conds ) ) {
1840 $sql = "SELECT $startOpts $fields $from $useIndex $ignoreIndex " .
1841 "WHERE $conds $preLimitTail";
1842 } else {
1843 throw new DBUnexpectedError( $this, __METHOD__ . ' called with incorrect parameters' );
1844 }
1845
1846 if ( isset( $options['LIMIT'] ) ) {
1847 $sql = $this->limitResult( $sql, $options['LIMIT'],
1848 $options['OFFSET'] ?? false );
1849 }
1850 $sql = "$sql $postLimitTail";
1851
1852 if ( isset( $options['EXPLAIN'] ) ) {
1853 $sql = 'EXPLAIN ' . $sql;
1854 }
1855
1856 return $sql;
1857 }
1858
1859 public function selectRow( $table, $vars, $conds, $fname = __METHOD__,
1860 $options = [], $join_conds = []
1861 ) {
1862 $options = (array)$options;
1863 $options['LIMIT'] = 1;
1864 $res = $this->select( $table, $vars, $conds, $fname, $options, $join_conds );
1865
1866 if ( $res === false ) {
1867 return false;
1868 }
1869
1870 if ( !$this->numRows( $res ) ) {
1871 return false;
1872 }
1873
1874 $obj = $this->fetchObject( $res );
1875
1876 return $obj;
1877 }
1878
1879 public function estimateRowCount(
1880 $table, $var = '*', $conds = '', $fname = __METHOD__, $options = [], $join_conds = []
1881 ) {
1882 $conds = $this->normalizeConditions( $conds, $fname );
1883 $column = $this->extractSingleFieldFromList( $var );
1884 if ( is_string( $column ) && !in_array( $column, [ '*', '1' ] ) ) {
1885 $conds[] = "$column IS NOT NULL";
1886 }
1887
1888 $res = $this->select(
1889 $table, [ 'rowcount' => 'COUNT(*)' ], $conds, $fname, $options, $join_conds
1890 );
1891 $row = $res ? $this->fetchRow( $res ) : [];
1892
1893 return isset( $row['rowcount'] ) ? (int)$row['rowcount'] : 0;
1894 }
1895
1896 public function selectRowCount(
1897 $tables, $var = '*', $conds = '', $fname = __METHOD__, $options = [], $join_conds = []
1898 ) {
1899 $conds = $this->normalizeConditions( $conds, $fname );
1900 $column = $this->extractSingleFieldFromList( $var );
1901 if ( is_string( $column ) && !in_array( $column, [ '*', '1' ] ) ) {
1902 $conds[] = "$column IS NOT NULL";
1903 }
1904
1905 $res = $this->select(
1906 [
1907 'tmp_count' => $this->buildSelectSubquery(
1908 $tables,
1909 '1',
1910 $conds,
1911 $fname,
1912 $options,
1913 $join_conds
1914 )
1915 ],
1916 [ 'rowcount' => 'COUNT(*)' ],
1917 [],
1918 $fname
1919 );
1920 $row = $res ? $this->fetchRow( $res ) : [];
1921
1922 return isset( $row['rowcount'] ) ? (int)$row['rowcount'] : 0;
1923 }
1924
1925 /**
1926 * @param string|array $options
1927 * @return bool
1928 */
1929 private function selectOptionsIncludeLocking( $options ) {
1930 $options = (array)$options;
1931 foreach ( [ 'FOR UPDATE', 'LOCK IN SHARE MODE' ] as $lock ) {
1932 if ( in_array( $lock, $options, true ) ) {
1933 return true;
1934 }
1935 }
1936
1937 return false;
1938 }
1939
1940 /**
1941 * @param array|string $fields
1942 * @param array|string $options
1943 * @return bool
1944 */
1945 private function selectFieldsOrOptionsAggregate( $fields, $options ) {
1946 foreach ( (array)$options as $key => $value ) {
1947 if ( is_string( $key ) ) {
1948 if ( preg_match( '/^(?:GROUP BY|HAVING)$/i', $key ) ) {
1949 return true;
1950 }
1951 } elseif ( is_string( $value ) ) {
1952 if ( preg_match( '/^(?:DISTINCT|DISTINCTROW)$/i', $value ) ) {
1953 return true;
1954 }
1955 }
1956 }
1957
1958 $regex = '/^(?:COUNT|MIN|MAX|SUM|GROUP_CONCAT|LISTAGG|ARRAY_AGG)\s*\\(/i';
1959 foreach ( (array)$fields as $field ) {
1960 if ( is_string( $field ) && preg_match( $regex, $field ) ) {
1961 return true;
1962 }
1963 }
1964
1965 return false;
1966 }
1967
1968 /**
1969 * @param array|string $conds
1970 * @param string $fname
1971 * @return array
1972 */
1973 final protected function normalizeConditions( $conds, $fname ) {
1974 if ( $conds === null || $conds === false ) {
1975 $this->queryLogger->warning(
1976 __METHOD__
1977 . ' called from '
1978 . $fname
1979 . ' with incorrect parameters: $conds must be a string or an array'
1980 );
1981 $conds = '';
1982 }
1983
1984 if ( !is_array( $conds ) ) {
1985 $conds = ( $conds === '' ) ? [] : [ $conds ];
1986 }
1987
1988 return $conds;
1989 }
1990
1991 /**
1992 * @param array|string $var Field parameter in the style of select()
1993 * @return string|null Column name or null; ignores aliases
1994 * @throws DBUnexpectedError Errors out if multiple columns are given
1995 */
1996 final protected function extractSingleFieldFromList( $var ) {
1997 if ( is_array( $var ) ) {
1998 if ( !$var ) {
1999 $column = null;
2000 } elseif ( count( $var ) == 1 ) {
2001 $column = $var[0] ?? reset( $var );
2002 } else {
2003 throw new DBUnexpectedError( $this, __METHOD__ . ': got multiple columns.' );
2004 }
2005 } else {
2006 $column = $var;
2007 }
2008
2009 return $column;
2010 }
2011
2012 public function lockForUpdate(
2013 $table, $conds = '', $fname = __METHOD__, $options = [], $join_conds = []
2014 ) {
2015 if ( !$this->trxLevel && !$this->getFlag( self::DBO_TRX ) ) {
2016 throw new DBUnexpectedError(
2017 $this,
2018 __METHOD__ . ': no transaction is active nor is DBO_TRX set'
2019 );
2020 }
2021
2022 $options = (array)$options;
2023 $options[] = 'FOR UPDATE';
2024
2025 return $this->selectRowCount( $table, '*', $conds, $fname, $options, $join_conds );
2026 }
2027
2028 /**
2029 * Removes most variables from an SQL query and replaces them with X or N for numbers.
2030 * It's only slightly flawed. Don't use for anything important.
2031 *
2032 * @param string $sql A SQL Query
2033 *
2034 * @return string
2035 */
2036 protected static function generalizeSQL( $sql ) {
2037 # This does the same as the regexp below would do, but in such a way
2038 # as to avoid crashing php on some large strings.
2039 # $sql = preg_replace( "/'([^\\\\']|\\\\.)*'|\"([^\\\\\"]|\\\\.)*\"/", "'X'", $sql );
2040
2041 $sql = str_replace( "\\\\", '', $sql );
2042 $sql = str_replace( "\\'", '', $sql );
2043 $sql = str_replace( "\\\"", '', $sql );
2044 $sql = preg_replace( "/'.*'/s", "'X'", $sql );
2045 $sql = preg_replace( '/".*"/s', "'X'", $sql );
2046
2047 # All newlines, tabs, etc replaced by single space
2048 $sql = preg_replace( '/\s+/', ' ', $sql );
2049
2050 # All numbers => N,
2051 # except the ones surrounded by characters, e.g. l10n
2052 $sql = preg_replace( '/-?\d+(,-?\d+)+/s', 'N,...,N', $sql );
2053 $sql = preg_replace( '/(?<![a-zA-Z])-?\d+(?![a-zA-Z])/s', 'N', $sql );
2054
2055 return $sql;
2056 }
2057
2058 public function fieldExists( $table, $field, $fname = __METHOD__ ) {
2059 $info = $this->fieldInfo( $table, $field );
2060
2061 return (bool)$info;
2062 }
2063
2064 public function indexExists( $table, $index, $fname = __METHOD__ ) {
2065 if ( !$this->tableExists( $table ) ) {
2066 return null;
2067 }
2068
2069 $info = $this->indexInfo( $table, $index, $fname );
2070 if ( is_null( $info ) ) {
2071 return null;
2072 } else {
2073 return $info !== false;
2074 }
2075 }
2076
2077 abstract public function tableExists( $table, $fname = __METHOD__ );
2078
2079 public function indexUnique( $table, $index ) {
2080 $indexInfo = $this->indexInfo( $table, $index );
2081
2082 if ( !$indexInfo ) {
2083 return null;
2084 }
2085
2086 return !$indexInfo[0]->Non_unique;
2087 }
2088
2089 /**
2090 * Helper for Database::insert().
2091 *
2092 * @param array $options
2093 * @return string
2094 */
2095 protected function makeInsertOptions( $options ) {
2096 return implode( ' ', $options );
2097 }
2098
2099 public function insert( $table, $a, $fname = __METHOD__, $options = [] ) {
2100 # No rows to insert, easy just return now
2101 if ( !count( $a ) ) {
2102 return true;
2103 }
2104
2105 $table = $this->tableName( $table );
2106
2107 if ( !is_array( $options ) ) {
2108 $options = [ $options ];
2109 }
2110
2111 $options = $this->makeInsertOptions( $options );
2112
2113 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
2114 $multi = true;
2115 $keys = array_keys( $a[0] );
2116 } else {
2117 $multi = false;
2118 $keys = array_keys( $a );
2119 }
2120
2121 $sql = 'INSERT ' . $options .
2122 " INTO $table (" . implode( ',', $keys ) . ') VALUES ';
2123
2124 if ( $multi ) {
2125 $first = true;
2126 foreach ( $a as $row ) {
2127 if ( $first ) {
2128 $first = false;
2129 } else {
2130 $sql .= ',';
2131 }
2132 $sql .= '(' . $this->makeList( $row ) . ')';
2133 }
2134 } else {
2135 $sql .= '(' . $this->makeList( $a ) . ')';
2136 }
2137
2138 $this->query( $sql, $fname );
2139
2140 return true;
2141 }
2142
2143 /**
2144 * Make UPDATE options array for Database::makeUpdateOptions
2145 *
2146 * @param array $options
2147 * @return array
2148 */
2149 protected function makeUpdateOptionsArray( $options ) {
2150 if ( !is_array( $options ) ) {
2151 $options = [ $options ];
2152 }
2153
2154 $opts = [];
2155
2156 if ( in_array( 'IGNORE', $options ) ) {
2157 $opts[] = 'IGNORE';
2158 }
2159
2160 return $opts;
2161 }
2162
2163 /**
2164 * Make UPDATE options for the Database::update function
2165 *
2166 * @param array $options The options passed to Database::update
2167 * @return string
2168 */
2169 protected function makeUpdateOptions( $options ) {
2170 $opts = $this->makeUpdateOptionsArray( $options );
2171
2172 return implode( ' ', $opts );
2173 }
2174
2175 public function update( $table, $values, $conds, $fname = __METHOD__, $options = [] ) {
2176 $table = $this->tableName( $table );
2177 $opts = $this->makeUpdateOptions( $options );
2178 $sql = "UPDATE $opts $table SET " . $this->makeList( $values, self::LIST_SET );
2179
2180 if ( $conds !== [] && $conds !== '*' ) {
2181 $sql .= " WHERE " . $this->makeList( $conds, self::LIST_AND );
2182 }
2183
2184 $this->query( $sql, $fname );
2185
2186 return true;
2187 }
2188
2189 public function makeList( $a, $mode = self::LIST_COMMA ) {
2190 if ( !is_array( $a ) ) {
2191 throw new DBUnexpectedError( $this, __METHOD__ . ' called with incorrect parameters' );
2192 }
2193
2194 $first = true;
2195 $list = '';
2196
2197 foreach ( $a as $field => $value ) {
2198 if ( !$first ) {
2199 if ( $mode == self::LIST_AND ) {
2200 $list .= ' AND ';
2201 } elseif ( $mode == self::LIST_OR ) {
2202 $list .= ' OR ';
2203 } else {
2204 $list .= ',';
2205 }
2206 } else {
2207 $first = false;
2208 }
2209
2210 if ( ( $mode == self::LIST_AND || $mode == self::LIST_OR ) && is_numeric( $field ) ) {
2211 $list .= "($value)";
2212 } elseif ( $mode == self::LIST_SET && is_numeric( $field ) ) {
2213 $list .= "$value";
2214 } elseif (
2215 ( $mode == self::LIST_AND || $mode == self::LIST_OR ) && is_array( $value )
2216 ) {
2217 // Remove null from array to be handled separately if found
2218 $includeNull = false;
2219 foreach ( array_keys( $value, null, true ) as $nullKey ) {
2220 $includeNull = true;
2221 unset( $value[$nullKey] );
2222 }
2223 if ( count( $value ) == 0 && !$includeNull ) {
2224 throw new InvalidArgumentException(
2225 __METHOD__ . ": empty input for field $field" );
2226 } elseif ( count( $value ) == 0 ) {
2227 // only check if $field is null
2228 $list .= "$field IS NULL";
2229 } else {
2230 // IN clause contains at least one valid element
2231 if ( $includeNull ) {
2232 // Group subconditions to ensure correct precedence
2233 $list .= '(';
2234 }
2235 if ( count( $value ) == 1 ) {
2236 // Special-case single values, as IN isn't terribly efficient
2237 // Don't necessarily assume the single key is 0; we don't
2238 // enforce linear numeric ordering on other arrays here.
2239 $value = array_values( $value )[0];
2240 $list .= $field . " = " . $this->addQuotes( $value );
2241 } else {
2242 $list .= $field . " IN (" . $this->makeList( $value ) . ") ";
2243 }
2244 // if null present in array, append IS NULL
2245 if ( $includeNull ) {
2246 $list .= " OR $field IS NULL)";
2247 }
2248 }
2249 } elseif ( $value === null ) {
2250 if ( $mode == self::LIST_AND || $mode == self::LIST_OR ) {
2251 $list .= "$field IS ";
2252 } elseif ( $mode == self::LIST_SET ) {
2253 $list .= "$field = ";
2254 }
2255 $list .= 'NULL';
2256 } else {
2257 if (
2258 $mode == self::LIST_AND || $mode == self::LIST_OR || $mode == self::LIST_SET
2259 ) {
2260 $list .= "$field = ";
2261 }
2262 $list .= $mode == self::LIST_NAMES ? $value : $this->addQuotes( $value );
2263 }
2264 }
2265
2266 return $list;
2267 }
2268
2269 public function makeWhereFrom2d( $data, $baseKey, $subKey ) {
2270 $conds = [];
2271
2272 foreach ( $data as $base => $sub ) {
2273 if ( count( $sub ) ) {
2274 $conds[] = $this->makeList(
2275 [ $baseKey => $base, $subKey => array_keys( $sub ) ],
2276 self::LIST_AND );
2277 }
2278 }
2279
2280 if ( $conds ) {
2281 return $this->makeList( $conds, self::LIST_OR );
2282 } else {
2283 // Nothing to search for...
2284 return false;
2285 }
2286 }
2287
2288 public function aggregateValue( $valuedata, $valuename = 'value' ) {
2289 return $valuename;
2290 }
2291
2292 public function bitNot( $field ) {
2293 return "(~$field)";
2294 }
2295
2296 public function bitAnd( $fieldLeft, $fieldRight ) {
2297 return "($fieldLeft & $fieldRight)";
2298 }
2299
2300 public function bitOr( $fieldLeft, $fieldRight ) {
2301 return "($fieldLeft | $fieldRight)";
2302 }
2303
2304 public function buildConcat( $stringList ) {
2305 return 'CONCAT(' . implode( ',', $stringList ) . ')';
2306 }
2307
2308 public function buildGroupConcatField(
2309 $delim, $table, $field, $conds = '', $join_conds = []
2310 ) {
2311 $fld = "GROUP_CONCAT($field SEPARATOR " . $this->addQuotes( $delim ) . ')';
2312
2313 return '(' . $this->selectSQLText( $table, $fld, $conds, null, [], $join_conds ) . ')';
2314 }
2315
2316 public function buildSubstring( $input, $startPosition, $length = null ) {
2317 $this->assertBuildSubstringParams( $startPosition, $length );
2318 $functionBody = "$input FROM $startPosition";
2319 if ( $length !== null ) {
2320 $functionBody .= " FOR $length";
2321 }
2322 return 'SUBSTRING(' . $functionBody . ')';
2323 }
2324
2325 /**
2326 * Check type and bounds for parameters to self::buildSubstring()
2327 *
2328 * All supported databases have substring functions that behave the same for
2329 * positive $startPosition and non-negative $length, but behaviors differ when
2330 * given 0 or negative $startPosition or negative $length. The simplest
2331 * solution to that is to just forbid those values.
2332 *
2333 * @param int $startPosition
2334 * @param int|null $length
2335 * @since 1.31
2336 */
2337 protected function assertBuildSubstringParams( $startPosition, $length ) {
2338 if ( !is_int( $startPosition ) || $startPosition <= 0 ) {
2339 throw new InvalidArgumentException(
2340 '$startPosition must be a positive integer'
2341 );
2342 }
2343 if ( !( is_int( $length ) && $length >= 0 || $length === null ) ) {
2344 throw new InvalidArgumentException(
2345 '$length must be null or an integer greater than or equal to 0'
2346 );
2347 }
2348 }
2349
2350 public function buildStringCast( $field ) {
2351 // In theory this should work for any standards-compliant
2352 // SQL implementation, although it may not be the best way to do it.
2353 return "CAST( $field AS CHARACTER )";
2354 }
2355
2356 public function buildIntegerCast( $field ) {
2357 return 'CAST( ' . $field . ' AS INTEGER )';
2358 }
2359
2360 public function buildSelectSubquery(
2361 $table, $vars, $conds = '', $fname = __METHOD__,
2362 $options = [], $join_conds = []
2363 ) {
2364 return new Subquery(
2365 $this->selectSQLText( $table, $vars, $conds, $fname, $options, $join_conds )
2366 );
2367 }
2368
2369 public function databasesAreIndependent() {
2370 return false;
2371 }
2372
2373 final public function selectDB( $db ) {
2374 $this->selectDomain( new DatabaseDomain(
2375 $db,
2376 $this->currentDomain->getSchema(),
2377 $this->currentDomain->getTablePrefix()
2378 ) );
2379
2380 return true;
2381 }
2382
2383 final public function selectDomain( $domain ) {
2384 $this->doSelectDomain( DatabaseDomain::newFromId( $domain ) );
2385 }
2386
2387 protected function doSelectDomain( DatabaseDomain $domain ) {
2388 $this->currentDomain = $domain;
2389 }
2390
2391 public function getDBname() {
2392 return $this->currentDomain->getDatabase();
2393 }
2394
2395 public function getServer() {
2396 return $this->server;
2397 }
2398
2399 public function tableName( $name, $format = 'quoted' ) {
2400 if ( $name instanceof Subquery ) {
2401 throw new DBUnexpectedError(
2402 $this,
2403 __METHOD__ . ': got Subquery instance when expecting a string.'
2404 );
2405 }
2406
2407 # Skip the entire process when we have a string quoted on both ends.
2408 # Note that we check the end so that we will still quote any use of
2409 # use of `database`.table. But won't break things if someone wants
2410 # to query a database table with a dot in the name.
2411 if ( $this->isQuotedIdentifier( $name ) ) {
2412 return $name;
2413 }
2414
2415 # Lets test for any bits of text that should never show up in a table
2416 # name. Basically anything like JOIN or ON which are actually part of
2417 # SQL queries, but may end up inside of the table value to combine
2418 # sql. Such as how the API is doing.
2419 # Note that we use a whitespace test rather than a \b test to avoid
2420 # any remote case where a word like on may be inside of a table name
2421 # surrounded by symbols which may be considered word breaks.
2422 if ( preg_match( '/(^|\s)(DISTINCT|JOIN|ON|AS)(\s|$)/i', $name ) !== 0 ) {
2423 $this->queryLogger->warning(
2424 __METHOD__ . ": use of subqueries is not supported this way.",
2425 [ 'trace' => ( new RuntimeException() )->getTraceAsString() ]
2426 );
2427
2428 return $name;
2429 }
2430
2431 # Split database and table into proper variables.
2432 list( $database, $schema, $prefix, $table ) = $this->qualifiedTableComponents( $name );
2433
2434 # Quote $table and apply the prefix if not quoted.
2435 # $tableName might be empty if this is called from Database::replaceVars()
2436 $tableName = "{$prefix}{$table}";
2437 if ( $format === 'quoted'
2438 && !$this->isQuotedIdentifier( $tableName )
2439 && $tableName !== ''
2440 ) {
2441 $tableName = $this->addIdentifierQuotes( $tableName );
2442 }
2443
2444 # Quote $schema and $database and merge them with the table name if needed
2445 $tableName = $this->prependDatabaseOrSchema( $schema, $tableName, $format );
2446 $tableName = $this->prependDatabaseOrSchema( $database, $tableName, $format );
2447
2448 return $tableName;
2449 }
2450
2451 /**
2452 * Get the table components needed for a query given the currently selected database
2453 *
2454 * @param string $name Table name in the form of db.schema.table, db.table, or table
2455 * @return array (DB name or "" for default, schema name, table prefix, table name)
2456 */
2457 protected function qualifiedTableComponents( $name ) {
2458 # We reverse the explode so that database.table and table both output the correct table.
2459 $dbDetails = explode( '.', $name, 3 );
2460 if ( count( $dbDetails ) == 3 ) {
2461 list( $database, $schema, $table ) = $dbDetails;
2462 # We don't want any prefix added in this case
2463 $prefix = '';
2464 } elseif ( count( $dbDetails ) == 2 ) {
2465 list( $database, $table ) = $dbDetails;
2466 # We don't want any prefix added in this case
2467 $prefix = '';
2468 # In dbs that support it, $database may actually be the schema
2469 # but that doesn't affect any of the functionality here
2470 $schema = '';
2471 } else {
2472 list( $table ) = $dbDetails;
2473 if ( isset( $this->tableAliases[$table] ) ) {
2474 $database = $this->tableAliases[$table]['dbname'];
2475 $schema = is_string( $this->tableAliases[$table]['schema'] )
2476 ? $this->tableAliases[$table]['schema']
2477 : $this->relationSchemaQualifier();
2478 $prefix = is_string( $this->tableAliases[$table]['prefix'] )
2479 ? $this->tableAliases[$table]['prefix']
2480 : $this->tablePrefix();
2481 } else {
2482 $database = '';
2483 $schema = $this->relationSchemaQualifier(); # Default schema
2484 $prefix = $this->tablePrefix(); # Default prefix
2485 }
2486 }
2487
2488 return [ $database, $schema, $prefix, $table ];
2489 }
2490
2491 /**
2492 * @param string|null $namespace Database or schema
2493 * @param string $relation Name of table, view, sequence, etc...
2494 * @param string $format One of (raw, quoted)
2495 * @return string Relation name with quoted and merged $namespace as needed
2496 */
2497 private function prependDatabaseOrSchema( $namespace, $relation, $format ) {
2498 if ( strlen( $namespace ) ) {
2499 if ( $format === 'quoted' && !$this->isQuotedIdentifier( $namespace ) ) {
2500 $namespace = $this->addIdentifierQuotes( $namespace );
2501 }
2502 $relation = $namespace . '.' . $relation;
2503 }
2504
2505 return $relation;
2506 }
2507
2508 public function tableNames() {
2509 $inArray = func_get_args();
2510 $retVal = [];
2511
2512 foreach ( $inArray as $name ) {
2513 $retVal[$name] = $this->tableName( $name );
2514 }
2515
2516 return $retVal;
2517 }
2518
2519 public function tableNamesN() {
2520 $inArray = func_get_args();
2521 $retVal = [];
2522
2523 foreach ( $inArray as $name ) {
2524 $retVal[] = $this->tableName( $name );
2525 }
2526
2527 return $retVal;
2528 }
2529
2530 /**
2531 * Get an aliased table name
2532 *
2533 * This returns strings like "tableName AS newTableName" for aliased tables
2534 * and "(SELECT * from tableA) newTablename" for subqueries (e.g. derived tables)
2535 *
2536 * @see Database::tableName()
2537 * @param string|Subquery $table Table name or object with a 'sql' field
2538 * @param string|bool $alias Table alias (optional)
2539 * @return string SQL name for aliased table. Will not alias a table to its own name
2540 */
2541 protected function tableNameWithAlias( $table, $alias = false ) {
2542 if ( is_string( $table ) ) {
2543 $quotedTable = $this->tableName( $table );
2544 } elseif ( $table instanceof Subquery ) {
2545 $quotedTable = (string)$table;
2546 } else {
2547 throw new InvalidArgumentException( "Table must be a string or Subquery." );
2548 }
2549
2550 if ( $alias === false || $alias === $table ) {
2551 if ( $table instanceof Subquery ) {
2552 throw new InvalidArgumentException( "Subquery table missing alias." );
2553 }
2554
2555 return $quotedTable;
2556 } else {
2557 return $quotedTable . ' ' . $this->addIdentifierQuotes( $alias );
2558 }
2559 }
2560
2561 /**
2562 * Gets an array of aliased table names
2563 *
2564 * @param array $tables [ [alias] => table ]
2565 * @return string[] See tableNameWithAlias()
2566 */
2567 protected function tableNamesWithAlias( $tables ) {
2568 $retval = [];
2569 foreach ( $tables as $alias => $table ) {
2570 if ( is_numeric( $alias ) ) {
2571 $alias = $table;
2572 }
2573 $retval[] = $this->tableNameWithAlias( $table, $alias );
2574 }
2575
2576 return $retval;
2577 }
2578
2579 /**
2580 * Get an aliased field name
2581 * e.g. fieldName AS newFieldName
2582 *
2583 * @param string $name Field name
2584 * @param string|bool $alias Alias (optional)
2585 * @return string SQL name for aliased field. Will not alias a field to its own name
2586 */
2587 protected function fieldNameWithAlias( $name, $alias = false ) {
2588 if ( !$alias || (string)$alias === (string)$name ) {
2589 return $name;
2590 } else {
2591 return $name . ' AS ' . $this->addIdentifierQuotes( $alias ); // PostgreSQL needs AS
2592 }
2593 }
2594
2595 /**
2596 * Gets an array of aliased field names
2597 *
2598 * @param array $fields [ [alias] => field ]
2599 * @return string[] See fieldNameWithAlias()
2600 */
2601 protected function fieldNamesWithAlias( $fields ) {
2602 $retval = [];
2603 foreach ( $fields as $alias => $field ) {
2604 if ( is_numeric( $alias ) ) {
2605 $alias = $field;
2606 }
2607 $retval[] = $this->fieldNameWithAlias( $field, $alias );
2608 }
2609
2610 return $retval;
2611 }
2612
2613 /**
2614 * Get the aliased table name clause for a FROM clause
2615 * which might have a JOIN and/or USE INDEX or IGNORE INDEX clause
2616 *
2617 * @param array $tables ( [alias] => table )
2618 * @param array $use_index Same as for select()
2619 * @param array $ignore_index Same as for select()
2620 * @param array $join_conds Same as for select()
2621 * @return string
2622 */
2623 protected function tableNamesWithIndexClauseOrJOIN(
2624 $tables, $use_index = [], $ignore_index = [], $join_conds = []
2625 ) {
2626 $ret = [];
2627 $retJOIN = [];
2628 $use_index = (array)$use_index;
2629 $ignore_index = (array)$ignore_index;
2630 $join_conds = (array)$join_conds;
2631
2632 foreach ( $tables as $alias => $table ) {
2633 if ( !is_string( $alias ) ) {
2634 // No alias? Set it equal to the table name
2635 $alias = $table;
2636 }
2637
2638 if ( is_array( $table ) ) {
2639 // A parenthesized group
2640 if ( count( $table ) > 1 ) {
2641 $joinedTable = '(' .
2642 $this->tableNamesWithIndexClauseOrJOIN(
2643 $table, $use_index, $ignore_index, $join_conds ) . ')';
2644 } else {
2645 // Degenerate case
2646 $innerTable = reset( $table );
2647 $innerAlias = key( $table );
2648 $joinedTable = $this->tableNameWithAlias(
2649 $innerTable,
2650 is_string( $innerAlias ) ? $innerAlias : $innerTable
2651 );
2652 }
2653 } else {
2654 $joinedTable = $this->tableNameWithAlias( $table, $alias );
2655 }
2656
2657 // Is there a JOIN clause for this table?
2658 if ( isset( $join_conds[$alias] ) ) {
2659 list( $joinType, $conds ) = $join_conds[$alias];
2660 $tableClause = $joinType;
2661 $tableClause .= ' ' . $joinedTable;
2662 if ( isset( $use_index[$alias] ) ) { // has USE INDEX?
2663 $use = $this->useIndexClause( implode( ',', (array)$use_index[$alias] ) );
2664 if ( $use != '' ) {
2665 $tableClause .= ' ' . $use;
2666 }
2667 }
2668 if ( isset( $ignore_index[$alias] ) ) { // has IGNORE INDEX?
2669 $ignore = $this->ignoreIndexClause(
2670 implode( ',', (array)$ignore_index[$alias] ) );
2671 if ( $ignore != '' ) {
2672 $tableClause .= ' ' . $ignore;
2673 }
2674 }
2675 $on = $this->makeList( (array)$conds, self::LIST_AND );
2676 if ( $on != '' ) {
2677 $tableClause .= ' ON (' . $on . ')';
2678 }
2679
2680 $retJOIN[] = $tableClause;
2681 } elseif ( isset( $use_index[$alias] ) ) {
2682 // Is there an INDEX clause for this table?
2683 $tableClause = $joinedTable;
2684 $tableClause .= ' ' . $this->useIndexClause(
2685 implode( ',', (array)$use_index[$alias] )
2686 );
2687
2688 $ret[] = $tableClause;
2689 } elseif ( isset( $ignore_index[$alias] ) ) {
2690 // Is there an INDEX clause for this table?
2691 $tableClause = $joinedTable;
2692 $tableClause .= ' ' . $this->ignoreIndexClause(
2693 implode( ',', (array)$ignore_index[$alias] )
2694 );
2695
2696 $ret[] = $tableClause;
2697 } else {
2698 $tableClause = $joinedTable;
2699
2700 $ret[] = $tableClause;
2701 }
2702 }
2703
2704 // We can't separate explicit JOIN clauses with ',', use ' ' for those
2705 $implicitJoins = $ret ? implode( ',', $ret ) : "";
2706 $explicitJoins = $retJOIN ? implode( ' ', $retJOIN ) : "";
2707
2708 // Compile our final table clause
2709 return implode( ' ', [ $implicitJoins, $explicitJoins ] );
2710 }
2711
2712 /**
2713 * Allows for index remapping in queries where this is not consistent across DBMS
2714 *
2715 * @param string $index
2716 * @return string
2717 */
2718 protected function indexName( $index ) {
2719 return $this->indexAliases[$index] ?? $index;
2720 }
2721
2722 public function addQuotes( $s ) {
2723 if ( $s instanceof Blob ) {
2724 $s = $s->fetch();
2725 }
2726 if ( $s === null ) {
2727 return 'NULL';
2728 } elseif ( is_bool( $s ) ) {
2729 return (int)$s;
2730 } else {
2731 # This will also quote numeric values. This should be harmless,
2732 # and protects against weird problems that occur when they really
2733 # _are_ strings such as article titles and string->number->string
2734 # conversion is not 1:1.
2735 return "'" . $this->strencode( $s ) . "'";
2736 }
2737 }
2738
2739 public function addIdentifierQuotes( $s ) {
2740 return '"' . str_replace( '"', '""', $s ) . '"';
2741 }
2742
2743 /**
2744 * Returns if the given identifier looks quoted or not according to
2745 * the database convention for quoting identifiers .
2746 *
2747 * @note Do not use this to determine if untrusted input is safe.
2748 * A malicious user can trick this function.
2749 * @param string $name
2750 * @return bool
2751 */
2752 public function isQuotedIdentifier( $name ) {
2753 return $name[0] == '"' && substr( $name, -1, 1 ) == '"';
2754 }
2755
2756 /**
2757 * @param string $s
2758 * @param string $escapeChar
2759 * @return string
2760 */
2761 protected function escapeLikeInternal( $s, $escapeChar = '`' ) {
2762 return str_replace( [ $escapeChar, '%', '_' ],
2763 [ "{$escapeChar}{$escapeChar}", "{$escapeChar}%", "{$escapeChar}_" ],
2764 $s );
2765 }
2766
2767 public function buildLike() {
2768 $params = func_get_args();
2769
2770 if ( count( $params ) > 0 && is_array( $params[0] ) ) {
2771 $params = $params[0];
2772 }
2773
2774 $s = '';
2775
2776 // We use ` instead of \ as the default LIKE escape character, since addQuotes()
2777 // may escape backslashes, creating problems of double escaping. The `
2778 // character has good cross-DBMS compatibility, avoiding special operators
2779 // in MS SQL like ^ and %
2780 $escapeChar = '`';
2781
2782 foreach ( $params as $value ) {
2783 if ( $value instanceof LikeMatch ) {
2784 $s .= $value->toString();
2785 } else {
2786 $s .= $this->escapeLikeInternal( $value, $escapeChar );
2787 }
2788 }
2789
2790 return ' LIKE ' .
2791 $this->addQuotes( $s ) . ' ESCAPE ' . $this->addQuotes( $escapeChar ) . ' ';
2792 }
2793
2794 public function anyChar() {
2795 return new LikeMatch( '_' );
2796 }
2797
2798 public function anyString() {
2799 return new LikeMatch( '%' );
2800 }
2801
2802 public function nextSequenceValue( $seqName ) {
2803 return null;
2804 }
2805
2806 /**
2807 * USE INDEX clause. Unlikely to be useful for anything but MySQL. This
2808 * is only needed because a) MySQL must be as efficient as possible due to
2809 * its use on Wikipedia, and b) MySQL 4.0 is kind of dumb sometimes about
2810 * which index to pick. Anyway, other databases might have different
2811 * indexes on a given table. So don't bother overriding this unless you're
2812 * MySQL.
2813 * @param string $index
2814 * @return string
2815 */
2816 public function useIndexClause( $index ) {
2817 return '';
2818 }
2819
2820 /**
2821 * IGNORE INDEX clause. Unlikely to be useful for anything but MySQL. This
2822 * is only needed because a) MySQL must be as efficient as possible due to
2823 * its use on Wikipedia, and b) MySQL 4.0 is kind of dumb sometimes about
2824 * which index to pick. Anyway, other databases might have different
2825 * indexes on a given table. So don't bother overriding this unless you're
2826 * MySQL.
2827 * @param string $index
2828 * @return string
2829 */
2830 public function ignoreIndexClause( $index ) {
2831 return '';
2832 }
2833
2834 public function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__ ) {
2835 if ( count( $rows ) == 0 ) {
2836 return;
2837 }
2838
2839 $uniqueIndexes = (array)$uniqueIndexes;
2840 // Single row case
2841 if ( !is_array( reset( $rows ) ) ) {
2842 $rows = [ $rows ];
2843 }
2844
2845 try {
2846 $this->startAtomic( $fname, self::ATOMIC_CANCELABLE );
2847 $affectedRowCount = 0;
2848 foreach ( $rows as $row ) {
2849 // Delete rows which collide with this one
2850 $indexWhereClauses = [];
2851 foreach ( $uniqueIndexes as $index ) {
2852 $indexColumns = (array)$index;
2853 $indexRowValues = array_intersect_key( $row, array_flip( $indexColumns ) );
2854 if ( count( $indexRowValues ) != count( $indexColumns ) ) {
2855 throw new DBUnexpectedError(
2856 $this,
2857 'New record does not provide all values for unique key (' .
2858 implode( ', ', $indexColumns ) . ')'
2859 );
2860 } elseif ( in_array( null, $indexRowValues, true ) ) {
2861 throw new DBUnexpectedError(
2862 $this,
2863 'New record has a null value for unique key (' .
2864 implode( ', ', $indexColumns ) . ')'
2865 );
2866 }
2867 $indexWhereClauses[] = $this->makeList( $indexRowValues, LIST_AND );
2868 }
2869
2870 if ( $indexWhereClauses ) {
2871 $this->delete( $table, $this->makeList( $indexWhereClauses, LIST_OR ), $fname );
2872 $affectedRowCount += $this->affectedRows();
2873 }
2874
2875 // Now insert the row
2876 $this->insert( $table, $row, $fname );
2877 $affectedRowCount += $this->affectedRows();
2878 }
2879 $this->endAtomic( $fname );
2880 $this->affectedRowCount = $affectedRowCount;
2881 } catch ( Exception $e ) {
2882 $this->cancelAtomic( $fname );
2883 throw $e;
2884 }
2885 }
2886
2887 /**
2888 * REPLACE query wrapper for MySQL and SQLite, which have a native REPLACE
2889 * statement.
2890 *
2891 * @param string $table Table name
2892 * @param array|string $rows Row(s) to insert
2893 * @param string $fname Caller function name
2894 */
2895 protected function nativeReplace( $table, $rows, $fname ) {
2896 $table = $this->tableName( $table );
2897
2898 # Single row case
2899 if ( !is_array( reset( $rows ) ) ) {
2900 $rows = [ $rows ];
2901 }
2902
2903 $sql = "REPLACE INTO $table (" . implode( ',', array_keys( $rows[0] ) ) . ') VALUES ';
2904 $first = true;
2905
2906 foreach ( $rows as $row ) {
2907 if ( $first ) {
2908 $first = false;
2909 } else {
2910 $sql .= ',';
2911 }
2912
2913 $sql .= '(' . $this->makeList( $row ) . ')';
2914 }
2915
2916 $this->query( $sql, $fname );
2917 }
2918
2919 public function upsert( $table, array $rows, $uniqueIndexes, array $set,
2920 $fname = __METHOD__
2921 ) {
2922 if ( $rows === [] ) {
2923 return true; // nothing to do
2924 }
2925
2926 $uniqueIndexes = (array)$uniqueIndexes;
2927 if ( !is_array( reset( $rows ) ) ) {
2928 $rows = [ $rows ];
2929 }
2930
2931 if ( count( $uniqueIndexes ) ) {
2932 $clauses = []; // list WHERE clauses that each identify a single row
2933 foreach ( $rows as $row ) {
2934 foreach ( $uniqueIndexes as $index ) {
2935 $index = is_array( $index ) ? $index : [ $index ]; // columns
2936 $rowKey = []; // unique key to this row
2937 foreach ( $index as $column ) {
2938 $rowKey[$column] = $row[$column];
2939 }
2940 $clauses[] = $this->makeList( $rowKey, self::LIST_AND );
2941 }
2942 }
2943 $where = [ $this->makeList( $clauses, self::LIST_OR ) ];
2944 } else {
2945 $where = false;
2946 }
2947
2948 $affectedRowCount = 0;
2949 try {
2950 $this->startAtomic( $fname, self::ATOMIC_CANCELABLE );
2951 # Update any existing conflicting row(s)
2952 if ( $where !== false ) {
2953 $this->update( $table, $set, $where, $fname );
2954 $affectedRowCount += $this->affectedRows();
2955 }
2956 # Now insert any non-conflicting row(s)
2957 $this->insert( $table, $rows, $fname, [ 'IGNORE' ] );
2958 $affectedRowCount += $this->affectedRows();
2959 $this->endAtomic( $fname );
2960 $this->affectedRowCount = $affectedRowCount;
2961 } catch ( Exception $e ) {
2962 $this->cancelAtomic( $fname );
2963 throw $e;
2964 }
2965
2966 return true;
2967 }
2968
2969 public function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds,
2970 $fname = __METHOD__
2971 ) {
2972 if ( !$conds ) {
2973 throw new DBUnexpectedError( $this, __METHOD__ . ' called with empty $conds' );
2974 }
2975
2976 $delTable = $this->tableName( $delTable );
2977 $joinTable = $this->tableName( $joinTable );
2978 $sql = "DELETE FROM $delTable WHERE $delVar IN (SELECT $joinVar FROM $joinTable ";
2979 if ( $conds != '*' ) {
2980 $sql .= 'WHERE ' . $this->makeList( $conds, self::LIST_AND );
2981 }
2982 $sql .= ')';
2983
2984 $this->query( $sql, $fname );
2985 }
2986
2987 public function textFieldSize( $table, $field ) {
2988 $table = $this->tableName( $table );
2989 $sql = "SHOW COLUMNS FROM $table LIKE \"$field\";";
2990 $res = $this->query( $sql, __METHOD__ );
2991 $row = $this->fetchObject( $res );
2992
2993 $m = [];
2994
2995 if ( preg_match( '/\((.*)\)/', $row->Type, $m ) ) {
2996 $size = $m[1];
2997 } else {
2998 $size = -1;
2999 }
3000
3001 return $size;
3002 }
3003
3004 public function delete( $table, $conds, $fname = __METHOD__ ) {
3005 if ( !$conds ) {
3006 throw new DBUnexpectedError( $this, __METHOD__ . ' called with no conditions' );
3007 }
3008
3009 $table = $this->tableName( $table );
3010 $sql = "DELETE FROM $table";
3011
3012 if ( $conds != '*' ) {
3013 if ( is_array( $conds ) ) {
3014 $conds = $this->makeList( $conds, self::LIST_AND );
3015 }
3016 $sql .= ' WHERE ' . $conds;
3017 }
3018
3019 $this->query( $sql, $fname );
3020
3021 return true;
3022 }
3023
3024 final public function insertSelect(
3025 $destTable, $srcTable, $varMap, $conds,
3026 $fname = __METHOD__, $insertOptions = [], $selectOptions = [], $selectJoinConds = []
3027 ) {
3028 static $hints = [ 'NO_AUTO_COLUMNS' ];
3029
3030 $insertOptions = (array)$insertOptions;
3031 $selectOptions = (array)$selectOptions;
3032
3033 if ( $this->cliMode && $this->isInsertSelectSafe( $insertOptions, $selectOptions ) ) {
3034 // For massive migrations with downtime, we don't want to select everything
3035 // into memory and OOM, so do all this native on the server side if possible.
3036 $this->nativeInsertSelect(
3037 $destTable,
3038 $srcTable,
3039 $varMap,
3040 $conds,
3041 $fname,
3042 array_diff( $insertOptions, $hints ),
3043 $selectOptions,
3044 $selectJoinConds
3045 );
3046 } else {
3047 $this->nonNativeInsertSelect(
3048 $destTable,
3049 $srcTable,
3050 $varMap,
3051 $conds,
3052 $fname,
3053 array_diff( $insertOptions, $hints ),
3054 $selectOptions,
3055 $selectJoinConds
3056 );
3057 }
3058
3059 return true;
3060 }
3061
3062 /**
3063 * @param array $insertOptions INSERT options
3064 * @param array $selectOptions SELECT options
3065 * @return bool Whether an INSERT SELECT with these options will be replication safe
3066 * @since 1.31
3067 */
3068 protected function isInsertSelectSafe( array $insertOptions, array $selectOptions ) {
3069 return true;
3070 }
3071
3072 /**
3073 * Implementation of insertSelect() based on select() and insert()
3074 *
3075 * @see IDatabase::insertSelect()
3076 * @since 1.30
3077 * @param string $destTable
3078 * @param string|array $srcTable
3079 * @param array $varMap
3080 * @param array $conds
3081 * @param string $fname
3082 * @param array $insertOptions
3083 * @param array $selectOptions
3084 * @param array $selectJoinConds
3085 */
3086 protected function nonNativeInsertSelect( $destTable, $srcTable, $varMap, $conds,
3087 $fname = __METHOD__,
3088 $insertOptions = [], $selectOptions = [], $selectJoinConds = []
3089 ) {
3090 // For web requests, do a locking SELECT and then INSERT. This puts the SELECT burden
3091 // on only the master (without needing row-based-replication). It also makes it easy to
3092 // know how big the INSERT is going to be.
3093 $fields = [];
3094 foreach ( $varMap as $dstColumn => $sourceColumnOrSql ) {
3095 $fields[] = $this->fieldNameWithAlias( $sourceColumnOrSql, $dstColumn );
3096 }
3097 $selectOptions[] = 'FOR UPDATE';
3098 $res = $this->select(
3099 $srcTable, implode( ',', $fields ), $conds, $fname, $selectOptions, $selectJoinConds
3100 );
3101 if ( !$res ) {
3102 return;
3103 }
3104
3105 try {
3106 $affectedRowCount = 0;
3107 $this->startAtomic( $fname, self::ATOMIC_CANCELABLE );
3108 $rows = [];
3109 $ok = true;
3110 foreach ( $res as $row ) {
3111 $rows[] = (array)$row;
3112
3113 // Avoid inserts that are too huge
3114 if ( count( $rows ) >= $this->nonNativeInsertSelectBatchSize ) {
3115 $ok = $this->insert( $destTable, $rows, $fname, $insertOptions );
3116 if ( !$ok ) {
3117 break;
3118 }
3119 $affectedRowCount += $this->affectedRows();
3120 $rows = [];
3121 }
3122 }
3123 if ( $rows && $ok ) {
3124 $ok = $this->insert( $destTable, $rows, $fname, $insertOptions );
3125 if ( $ok ) {
3126 $affectedRowCount += $this->affectedRows();
3127 }
3128 }
3129 if ( $ok ) {
3130 $this->endAtomic( $fname );
3131 $this->affectedRowCount = $affectedRowCount;
3132 } else {
3133 $this->cancelAtomic( $fname );
3134 }
3135 } catch ( Exception $e ) {
3136 $this->cancelAtomic( $fname );
3137 throw $e;
3138 }
3139 }
3140
3141 /**
3142 * Native server-side implementation of insertSelect() for situations where
3143 * we don't want to select everything into memory
3144 *
3145 * @see IDatabase::insertSelect()
3146 * @param string $destTable
3147 * @param string|array $srcTable
3148 * @param array $varMap
3149 * @param array $conds
3150 * @param string $fname
3151 * @param array $insertOptions
3152 * @param array $selectOptions
3153 * @param array $selectJoinConds
3154 */
3155 protected function nativeInsertSelect( $destTable, $srcTable, $varMap, $conds,
3156 $fname = __METHOD__,
3157 $insertOptions = [], $selectOptions = [], $selectJoinConds = []
3158 ) {
3159 $destTable = $this->tableName( $destTable );
3160
3161 if ( !is_array( $insertOptions ) ) {
3162 $insertOptions = [ $insertOptions ];
3163 }
3164
3165 $insertOptions = $this->makeInsertOptions( $insertOptions );
3166
3167 $selectSql = $this->selectSQLText(
3168 $srcTable,
3169 array_values( $varMap ),
3170 $conds,
3171 $fname,
3172 $selectOptions,
3173 $selectJoinConds
3174 );
3175
3176 $sql = "INSERT $insertOptions" .
3177 " INTO $destTable (" . implode( ',', array_keys( $varMap ) ) . ') ' .
3178 $selectSql;
3179
3180 $this->query( $sql, $fname );
3181 }
3182
3183 /**
3184 * Construct a LIMIT query with optional offset. This is used for query
3185 * pages. The SQL should be adjusted so that only the first $limit rows
3186 * are returned. If $offset is provided as well, then the first $offset
3187 * rows should be discarded, and the next $limit rows should be returned.
3188 * If the result of the query is not ordered, then the rows to be returned
3189 * are theoretically arbitrary.
3190 *
3191 * $sql is expected to be a SELECT, if that makes a difference.
3192 *
3193 * The version provided by default works in MySQL and SQLite. It will very
3194 * likely need to be overridden for most other DBMSes.
3195 *
3196 * @param string $sql SQL query we will append the limit too
3197 * @param int $limit The SQL limit
3198 * @param int|bool $offset The SQL offset (default false)
3199 * @throws DBUnexpectedError
3200 * @return string
3201 */
3202 public function limitResult( $sql, $limit, $offset = false ) {
3203 if ( !is_numeric( $limit ) ) {
3204 throw new DBUnexpectedError( $this,
3205 "Invalid non-numeric limit passed to limitResult()\n" );
3206 }
3207
3208 return "$sql LIMIT "
3209 . ( ( is_numeric( $offset ) && $offset != 0 ) ? "{$offset}," : "" )
3210 . "{$limit} ";
3211 }
3212
3213 public function unionSupportsOrderAndLimit() {
3214 return true; // True for almost every DB supported
3215 }
3216
3217 public function unionQueries( $sqls, $all ) {
3218 $glue = $all ? ') UNION ALL (' : ') UNION (';
3219
3220 return '(' . implode( $glue, $sqls ) . ')';
3221 }
3222
3223 public function unionConditionPermutations(
3224 $table, $vars, array $permute_conds, $extra_conds = '', $fname = __METHOD__,
3225 $options = [], $join_conds = []
3226 ) {
3227 // First, build the Cartesian product of $permute_conds
3228 $conds = [ [] ];
3229 foreach ( $permute_conds as $field => $values ) {
3230 if ( !$values ) {
3231 // Skip empty $values
3232 continue;
3233 }
3234 $values = array_unique( $values ); // For sanity
3235 $newConds = [];
3236 foreach ( $conds as $cond ) {
3237 foreach ( $values as $value ) {
3238 $cond[$field] = $value;
3239 $newConds[] = $cond; // Arrays are by-value, not by-reference, so this works
3240 }
3241 }
3242 $conds = $newConds;
3243 }
3244
3245 $extra_conds = $extra_conds === '' ? [] : (array)$extra_conds;
3246
3247 // If there's just one condition and no subordering, hand off to
3248 // selectSQLText directly.
3249 if ( count( $conds ) === 1 &&
3250 ( !isset( $options['INNER ORDER BY'] ) || !$this->unionSupportsOrderAndLimit() )
3251 ) {
3252 return $this->selectSQLText(
3253 $table, $vars, $conds[0] + $extra_conds, $fname, $options, $join_conds
3254 );
3255 }
3256
3257 // Otherwise, we need to pull out the order and limit to apply after
3258 // the union. Then build the SQL queries for each set of conditions in
3259 // $conds. Then union them together (using UNION ALL, because the
3260 // product *should* already be distinct).
3261 $orderBy = $this->makeOrderBy( $options );
3262 $limit = $options['LIMIT'] ?? null;
3263 $offset = $options['OFFSET'] ?? false;
3264 $all = empty( $options['NOTALL'] ) && !in_array( 'NOTALL', $options );
3265 if ( !$this->unionSupportsOrderAndLimit() ) {
3266 unset( $options['ORDER BY'], $options['LIMIT'], $options['OFFSET'] );
3267 } else {
3268 if ( array_key_exists( 'INNER ORDER BY', $options ) ) {
3269 $options['ORDER BY'] = $options['INNER ORDER BY'];
3270 }
3271 if ( $limit !== null && is_numeric( $offset ) && $offset != 0 ) {
3272 // We need to increase the limit by the offset rather than
3273 // using the offset directly, otherwise it'll skip incorrectly
3274 // in the subqueries.
3275 $options['LIMIT'] = $limit + $offset;
3276 unset( $options['OFFSET'] );
3277 }
3278 }
3279
3280 $sqls = [];
3281 foreach ( $conds as $cond ) {
3282 $sqls[] = $this->selectSQLText(
3283 $table, $vars, $cond + $extra_conds, $fname, $options, $join_conds
3284 );
3285 }
3286 $sql = $this->unionQueries( $sqls, $all ) . $orderBy;
3287 if ( $limit !== null ) {
3288 $sql = $this->limitResult( $sql, $limit, $offset );
3289 }
3290
3291 return $sql;
3292 }
3293
3294 public function conditional( $cond, $trueVal, $falseVal ) {
3295 if ( is_array( $cond ) ) {
3296 $cond = $this->makeList( $cond, self::LIST_AND );
3297 }
3298
3299 return " (CASE WHEN $cond THEN $trueVal ELSE $falseVal END) ";
3300 }
3301
3302 public function strreplace( $orig, $old, $new ) {
3303 return "REPLACE({$orig}, {$old}, {$new})";
3304 }
3305
3306 public function getServerUptime() {
3307 return 0;
3308 }
3309
3310 public function wasDeadlock() {
3311 return false;
3312 }
3313
3314 public function wasLockTimeout() {
3315 return false;
3316 }
3317
3318 public function wasConnectionLoss() {
3319 return $this->wasConnectionError( $this->lastErrno() );
3320 }
3321
3322 public function wasReadOnlyError() {
3323 return false;
3324 }
3325
3326 public function wasErrorReissuable() {
3327 return (
3328 $this->wasDeadlock() ||
3329 $this->wasLockTimeout() ||
3330 $this->wasConnectionLoss()
3331 );
3332 }
3333
3334 /**
3335 * Do not use this method outside of Database/DBError classes
3336 *
3337 * @param int|string $errno
3338 * @return bool Whether the given query error was a connection drop
3339 */
3340 public function wasConnectionError( $errno ) {
3341 return false;
3342 }
3343
3344 /**
3345 * @return bool Whether it is known that the last query error only caused statement rollback
3346 * @note This is for backwards compatibility for callers catching DBError exceptions in
3347 * order to ignore problems like duplicate key errors or foriegn key violations
3348 * @since 1.31
3349 */
3350 protected function wasKnownStatementRollbackError() {
3351 return false; // don't know; it could have caused a transaction rollback
3352 }
3353
3354 public function deadlockLoop() {
3355 $args = func_get_args();
3356 $function = array_shift( $args );
3357 $tries = self::DEADLOCK_TRIES;
3358
3359 $this->begin( __METHOD__ );
3360
3361 $retVal = null;
3362 /** @var Exception $e */
3363 $e = null;
3364 do {
3365 try {
3366 $retVal = $function( ...$args );
3367 break;
3368 } catch ( DBQueryError $e ) {
3369 if ( $this->wasDeadlock() ) {
3370 // Retry after a randomized delay
3371 usleep( mt_rand( self::DEADLOCK_DELAY_MIN, self::DEADLOCK_DELAY_MAX ) );
3372 } else {
3373 // Throw the error back up
3374 throw $e;
3375 }
3376 }
3377 } while ( --$tries > 0 );
3378
3379 if ( $tries <= 0 ) {
3380 // Too many deadlocks; give up
3381 $this->rollback( __METHOD__ );
3382 throw $e;
3383 } else {
3384 $this->commit( __METHOD__ );
3385
3386 return $retVal;
3387 }
3388 }
3389
3390 public function masterPosWait( DBMasterPos $pos, $timeout ) {
3391 # Real waits are implemented in the subclass.
3392 return 0;
3393 }
3394
3395 public function getReplicaPos() {
3396 # Stub
3397 return false;
3398 }
3399
3400 public function getMasterPos() {
3401 # Stub
3402 return false;
3403 }
3404
3405 public function serverIsReadOnly() {
3406 return false;
3407 }
3408
3409 final public function onTransactionResolution( callable $callback, $fname = __METHOD__ ) {
3410 if ( !$this->trxLevel ) {
3411 throw new DBUnexpectedError( $this, "No transaction is active." );
3412 }
3413 $this->trxEndCallbacks[] = [ $callback, $fname, $this->currentAtomicSectionId() ];
3414 }
3415
3416 final public function onTransactionCommitOrIdle( callable $callback, $fname = __METHOD__ ) {
3417 if ( !$this->trxLevel && $this->getTransactionRoundId() ) {
3418 // Start an implicit transaction similar to how query() does
3419 $this->begin( __METHOD__, self::TRANSACTION_INTERNAL );
3420 $this->trxAutomatic = true;
3421 }
3422
3423 $this->trxIdleCallbacks[] = [ $callback, $fname, $this->currentAtomicSectionId() ];
3424 if ( !$this->trxLevel ) {
3425 $this->runOnTransactionIdleCallbacks( self::TRIGGER_IDLE );
3426 }
3427 }
3428
3429 final public function onTransactionIdle( callable $callback, $fname = __METHOD__ ) {
3430 $this->onTransactionCommitOrIdle( $callback, $fname );
3431 }
3432
3433 final public function onTransactionPreCommitOrIdle( callable $callback, $fname = __METHOD__ ) {
3434 if ( !$this->trxLevel && $this->getTransactionRoundId() ) {
3435 // Start an implicit transaction similar to how query() does
3436 $this->begin( __METHOD__, self::TRANSACTION_INTERNAL );
3437 $this->trxAutomatic = true;
3438 }
3439
3440 if ( $this->trxLevel ) {
3441 $this->trxPreCommitCallbacks[] = [ $callback, $fname, $this->currentAtomicSectionId() ];
3442 } else {
3443 // No transaction is active nor will start implicitly, so make one for this callback
3444 $this->startAtomic( __METHOD__, self::ATOMIC_CANCELABLE );
3445 try {
3446 $callback( $this );
3447 $this->endAtomic( __METHOD__ );
3448 } catch ( Exception $e ) {
3449 $this->cancelAtomic( __METHOD__ );
3450 throw $e;
3451 }
3452 }
3453 }
3454
3455 /**
3456 * @return AtomicSectionIdentifier|null ID of the topmost atomic section level
3457 */
3458 private function currentAtomicSectionId() {
3459 if ( $this->trxLevel && $this->trxAtomicLevels ) {
3460 $levelInfo = end( $this->trxAtomicLevels );
3461
3462 return $levelInfo[1];
3463 }
3464
3465 return null;
3466 }
3467
3468 /**
3469 * @param AtomicSectionIdentifier $old
3470 * @param AtomicSectionIdentifier $new
3471 */
3472 private function reassignCallbacksForSection(
3473 AtomicSectionIdentifier $old, AtomicSectionIdentifier $new
3474 ) {
3475 foreach ( $this->trxPreCommitCallbacks as $key => $info ) {
3476 if ( $info[2] === $old ) {
3477 $this->trxPreCommitCallbacks[$key][2] = $new;
3478 }
3479 }
3480 foreach ( $this->trxIdleCallbacks as $key => $info ) {
3481 if ( $info[2] === $old ) {
3482 $this->trxIdleCallbacks[$key][2] = $new;
3483 }
3484 }
3485 foreach ( $this->trxEndCallbacks as $key => $info ) {
3486 if ( $info[2] === $old ) {
3487 $this->trxEndCallbacks[$key][2] = $new;
3488 }
3489 }
3490 }
3491
3492 /**
3493 * @param AtomicSectionIdentifier[] $sectionIds ID of an actual savepoint
3494 * @throws UnexpectedValueException
3495 */
3496 private function modifyCallbacksForCancel( array $sectionIds ) {
3497 // Cancel the "on commit" callbacks owned by this savepoint
3498 $this->trxIdleCallbacks = array_filter(
3499 $this->trxIdleCallbacks,
3500 function ( $entry ) use ( $sectionIds ) {
3501 return !in_array( $entry[2], $sectionIds, true );
3502 }
3503 );
3504 $this->trxPreCommitCallbacks = array_filter(
3505 $this->trxPreCommitCallbacks,
3506 function ( $entry ) use ( $sectionIds ) {
3507 return !in_array( $entry[2], $sectionIds, true );
3508 }
3509 );
3510 // Make "on resolution" callbacks owned by this savepoint to perceive a rollback
3511 foreach ( $this->trxEndCallbacks as $key => $entry ) {
3512 if ( in_array( $entry[2], $sectionIds, true ) ) {
3513 $callback = $entry[0];
3514 $this->trxEndCallbacks[$key][0] = function () use ( $callback ) {
3515 return $callback( self::TRIGGER_ROLLBACK, $this );
3516 };
3517 }
3518 }
3519 }
3520
3521 final public function setTransactionListener( $name, callable $callback = null ) {
3522 if ( $callback ) {
3523 $this->trxRecurringCallbacks[$name] = $callback;
3524 } else {
3525 unset( $this->trxRecurringCallbacks[$name] );
3526 }
3527 }
3528
3529 /**
3530 * Whether to disable running of post-COMMIT/ROLLBACK callbacks
3531 *
3532 * This method should not be used outside of Database/LoadBalancer
3533 *
3534 * @param bool $suppress
3535 * @since 1.28
3536 */
3537 final public function setTrxEndCallbackSuppression( $suppress ) {
3538 $this->trxEndCallbacksSuppressed = $suppress;
3539 }
3540
3541 /**
3542 * Actually consume and run any "on transaction idle/resolution" callbacks.
3543 *
3544 * This method should not be used outside of Database/LoadBalancer
3545 *
3546 * @param int $trigger IDatabase::TRIGGER_* constant
3547 * @return int Number of callbacks attempted
3548 * @since 1.20
3549 * @throws Exception
3550 */
3551 public function runOnTransactionIdleCallbacks( $trigger ) {
3552 if ( $this->trxLevel ) { // sanity
3553 throw new DBUnexpectedError( $this, __METHOD__ . ': a transaction is still open.' );
3554 }
3555
3556 if ( $this->trxEndCallbacksSuppressed ) {
3557 return 0;
3558 }
3559
3560 $count = 0;
3561 $autoTrx = $this->getFlag( self::DBO_TRX ); // automatic begin() enabled?
3562 /** @var Exception $e */
3563 $e = null; // first exception
3564 do { // callbacks may add callbacks :)
3565 $callbacks = array_merge(
3566 $this->trxIdleCallbacks,
3567 $this->trxEndCallbacks // include "transaction resolution" callbacks
3568 );
3569 $this->trxIdleCallbacks = []; // consumed (and recursion guard)
3570 $this->trxEndCallbacks = []; // consumed (recursion guard)
3571 foreach ( $callbacks as $callback ) {
3572 ++$count;
3573 list( $phpCallback ) = $callback;
3574 $this->clearFlag( self::DBO_TRX ); // make each query its own transaction
3575 try {
3576 call_user_func( $phpCallback, $trigger, $this );
3577 } catch ( Exception $ex ) {
3578 call_user_func( $this->errorLogger, $ex );
3579 $e = $e ?: $ex;
3580 // Some callbacks may use startAtomic/endAtomic, so make sure
3581 // their transactions are ended so other callbacks don't fail
3582 if ( $this->trxLevel() ) {
3583 $this->rollback( __METHOD__, self::FLUSHING_INTERNAL );
3584 }
3585 } finally {
3586 if ( $autoTrx ) {
3587 $this->setFlag( self::DBO_TRX ); // restore automatic begin()
3588 } else {
3589 $this->clearFlag( self::DBO_TRX ); // restore auto-commit
3590 }
3591 }
3592 }
3593 } while ( count( $this->trxIdleCallbacks ) );
3594
3595 if ( $e instanceof Exception ) {
3596 throw $e; // re-throw any first exception
3597 }
3598
3599 return $count;
3600 }
3601
3602 /**
3603 * Actually consume and run any "on transaction pre-commit" callbacks.
3604 *
3605 * This method should not be used outside of Database/LoadBalancer
3606 *
3607 * @since 1.22
3608 * @return int Number of callbacks attempted
3609 * @throws Exception
3610 */
3611 public function runOnTransactionPreCommitCallbacks() {
3612 $count = 0;
3613
3614 $e = null; // first exception
3615 do { // callbacks may add callbacks :)
3616 $callbacks = $this->trxPreCommitCallbacks;
3617 $this->trxPreCommitCallbacks = []; // consumed (and recursion guard)
3618 foreach ( $callbacks as $callback ) {
3619 try {
3620 ++$count;
3621 list( $phpCallback ) = $callback;
3622 $phpCallback( $this );
3623 } catch ( Exception $ex ) {
3624 ( $this->errorLogger )( $ex );
3625 $e = $e ?: $ex;
3626 }
3627 }
3628 } while ( count( $this->trxPreCommitCallbacks ) );
3629
3630 if ( $e instanceof Exception ) {
3631 throw $e; // re-throw any first exception
3632 }
3633
3634 return $count;
3635 }
3636
3637 /**
3638 * Actually run any "transaction listener" callbacks.
3639 *
3640 * This method should not be used outside of Database/LoadBalancer
3641 *
3642 * @param int $trigger IDatabase::TRIGGER_* constant
3643 * @throws Exception
3644 * @since 1.20
3645 */
3646 public function runTransactionListenerCallbacks( $trigger ) {
3647 if ( $this->trxEndCallbacksSuppressed ) {
3648 return;
3649 }
3650
3651 /** @var Exception $e */
3652 $e = null; // first exception
3653
3654 foreach ( $this->trxRecurringCallbacks as $phpCallback ) {
3655 try {
3656 $phpCallback( $trigger, $this );
3657 } catch ( Exception $ex ) {
3658 ( $this->errorLogger )( $ex );
3659 $e = $e ?: $ex;
3660 }
3661 }
3662
3663 if ( $e instanceof Exception ) {
3664 throw $e; // re-throw any first exception
3665 }
3666 }
3667
3668 /**
3669 * Create a savepoint
3670 *
3671 * This is used internally to implement atomic sections. It should not be
3672 * used otherwise.
3673 *
3674 * @since 1.31
3675 * @param string $identifier Identifier for the savepoint
3676 * @param string $fname Calling function name
3677 */
3678 protected function doSavepoint( $identifier, $fname ) {
3679 $this->query( 'SAVEPOINT ' . $this->addIdentifierQuotes( $identifier ), $fname );
3680 }
3681
3682 /**
3683 * Release a savepoint
3684 *
3685 * This is used internally to implement atomic sections. It should not be
3686 * used otherwise.
3687 *
3688 * @since 1.31
3689 * @param string $identifier Identifier for the savepoint
3690 * @param string $fname Calling function name
3691 */
3692 protected function doReleaseSavepoint( $identifier, $fname ) {
3693 $this->query( 'RELEASE SAVEPOINT ' . $this->addIdentifierQuotes( $identifier ), $fname );
3694 }
3695
3696 /**
3697 * Rollback to a savepoint
3698 *
3699 * This is used internally to implement atomic sections. It should not be
3700 * used otherwise.
3701 *
3702 * @since 1.31
3703 * @param string $identifier Identifier for the savepoint
3704 * @param string $fname Calling function name
3705 */
3706 protected function doRollbackToSavepoint( $identifier, $fname ) {
3707 $this->query( 'ROLLBACK TO SAVEPOINT ' . $this->addIdentifierQuotes( $identifier ), $fname );
3708 }
3709
3710 /**
3711 * @param string $fname
3712 * @return string
3713 */
3714 private function nextSavepointId( $fname ) {
3715 $savepointId = self::$SAVEPOINT_PREFIX . ++$this->trxAtomicCounter;
3716 if ( strlen( $savepointId ) > 30 ) {
3717 // 30 == Oracle's identifier length limit (pre 12c)
3718 // With a 22 character prefix, that puts the highest number at 99999999.
3719 throw new DBUnexpectedError(
3720 $this,
3721 'There have been an excessively large number of atomic sections in a transaction'
3722 . " started by $this->trxFname (at $fname)"
3723 );
3724 }
3725
3726 return $savepointId;
3727 }
3728
3729 final public function startAtomic(
3730 $fname = __METHOD__, $cancelable = self::ATOMIC_NOT_CANCELABLE
3731 ) {
3732 $savepointId = $cancelable === self::ATOMIC_CANCELABLE ? self::$NOT_APPLICABLE : null;
3733
3734 if ( !$this->trxLevel ) {
3735 $this->begin( $fname, self::TRANSACTION_INTERNAL ); // sets trxAutomatic
3736 // If DBO_TRX is set, a series of startAtomic/endAtomic pairs will result
3737 // in all changes being in one transaction to keep requests transactional.
3738 if ( $this->getFlag( self::DBO_TRX ) ) {
3739 // Since writes could happen in between the topmost atomic sections as part
3740 // of the transaction, those sections will need savepoints.
3741 $savepointId = $this->nextSavepointId( $fname );
3742 $this->doSavepoint( $savepointId, $fname );
3743 } else {
3744 $this->trxAutomaticAtomic = true;
3745 }
3746 } elseif ( $cancelable === self::ATOMIC_CANCELABLE ) {
3747 $savepointId = $this->nextSavepointId( $fname );
3748 $this->doSavepoint( $savepointId, $fname );
3749 }
3750
3751 $sectionId = new AtomicSectionIdentifier;
3752 $this->trxAtomicLevels[] = [ $fname, $sectionId, $savepointId ];
3753 $this->queryLogger->debug( 'startAtomic: entering level ' .
3754 ( count( $this->trxAtomicLevels ) - 1 ) . " ($fname)" );
3755
3756 return $sectionId;
3757 }
3758
3759 final public function endAtomic( $fname = __METHOD__ ) {
3760 if ( !$this->trxLevel || !$this->trxAtomicLevels ) {
3761 throw new DBUnexpectedError( $this, "No atomic section is open (got $fname)." );
3762 }
3763
3764 // Check if the current section matches $fname
3765 $pos = count( $this->trxAtomicLevels ) - 1;
3766 list( $savedFname, $sectionId, $savepointId ) = $this->trxAtomicLevels[$pos];
3767 $this->queryLogger->debug( "endAtomic: leaving level $pos ($fname)" );
3768
3769 if ( $savedFname !== $fname ) {
3770 throw new DBUnexpectedError(
3771 $this,
3772 "Invalid atomic section ended (got $fname but expected $savedFname)."
3773 );
3774 }
3775
3776 // Remove the last section (no need to re-index the array)
3777 array_pop( $this->trxAtomicLevels );
3778
3779 if ( !$this->trxAtomicLevels && $this->trxAutomaticAtomic ) {
3780 $this->commit( $fname, self::FLUSHING_INTERNAL );
3781 } elseif ( $savepointId !== null && $savepointId !== self::$NOT_APPLICABLE ) {
3782 $this->doReleaseSavepoint( $savepointId, $fname );
3783 }
3784
3785 // Hoist callback ownership for callbacks in the section that just ended;
3786 // all callbacks should have an owner that is present in trxAtomicLevels.
3787 $currentSectionId = $this->currentAtomicSectionId();
3788 if ( $currentSectionId ) {
3789 $this->reassignCallbacksForSection( $sectionId, $currentSectionId );
3790 }
3791 }
3792
3793 final public function cancelAtomic(
3794 $fname = __METHOD__, AtomicSectionIdentifier $sectionId = null
3795 ) {
3796 if ( !$this->trxLevel || !$this->trxAtomicLevels ) {
3797 throw new DBUnexpectedError( $this, "No atomic section is open (got $fname)." );
3798 }
3799
3800 $excisedFnames = [];
3801 if ( $sectionId !== null ) {
3802 // Find the (last) section with the given $sectionId
3803 $pos = -1;
3804 foreach ( $this->trxAtomicLevels as $i => list( $asFname, $asId, $spId ) ) {
3805 if ( $asId === $sectionId ) {
3806 $pos = $i;
3807 }
3808 }
3809 if ( $pos < 0 ) {
3810 throw new DBUnexpectedError( $this, "Atomic section not found (for $fname)" );
3811 }
3812 // Remove all descendant sections and re-index the array
3813 $excisedIds = [];
3814 $len = count( $this->trxAtomicLevels );
3815 for ( $i = $pos + 1; $i < $len; ++$i ) {
3816 $excisedFnames[] = $this->trxAtomicLevels[$i][0];
3817 $excisedIds[] = $this->trxAtomicLevels[$i][1];
3818 }
3819 $this->trxAtomicLevels = array_slice( $this->trxAtomicLevels, 0, $pos + 1 );
3820 $this->modifyCallbacksForCancel( $excisedIds );
3821 }
3822
3823 // Check if the current section matches $fname
3824 $pos = count( $this->trxAtomicLevels ) - 1;
3825 list( $savedFname, $savedSectionId, $savepointId ) = $this->trxAtomicLevels[$pos];
3826
3827 if ( $excisedFnames ) {
3828 $this->queryLogger->debug( "cancelAtomic: canceling level $pos ($savedFname) " .
3829 "and descendants " . implode( ', ', $excisedFnames ) );
3830 } else {
3831 $this->queryLogger->debug( "cancelAtomic: canceling level $pos ($savedFname)" );
3832 }
3833
3834 if ( $savedFname !== $fname ) {
3835 throw new DBUnexpectedError(
3836 $this,
3837 "Invalid atomic section ended (got $fname but expected $savedFname)."
3838 );
3839 }
3840
3841 // Remove the last section (no need to re-index the array)
3842 array_pop( $this->trxAtomicLevels );
3843 $this->modifyCallbacksForCancel( [ $savedSectionId ] );
3844
3845 if ( $savepointId !== null ) {
3846 // Rollback the transaction to the state just before this atomic section
3847 if ( $savepointId === self::$NOT_APPLICABLE ) {
3848 $this->rollback( $fname, self::FLUSHING_INTERNAL );
3849 } else {
3850 $this->doRollbackToSavepoint( $savepointId, $fname );
3851 $this->trxStatus = self::STATUS_TRX_OK; // no exception; recovered
3852 $this->trxStatusIgnoredCause = null;
3853 }
3854 } elseif ( $this->trxStatus > self::STATUS_TRX_ERROR ) {
3855 // Put the transaction into an error state if it's not already in one
3856 $this->trxStatus = self::STATUS_TRX_ERROR;
3857 $this->trxStatusCause = new DBUnexpectedError(
3858 $this,
3859 "Uncancelable atomic section canceled (got $fname)."
3860 );
3861 }
3862
3863 $this->affectedRowCount = 0; // for the sake of consistency
3864 }
3865
3866 final public function doAtomicSection(
3867 $fname, callable $callback, $cancelable = self::ATOMIC_NOT_CANCELABLE
3868 ) {
3869 $sectionId = $this->startAtomic( $fname, $cancelable );
3870 try {
3871 $res = $callback( $this, $fname );
3872 } catch ( Exception $e ) {
3873 $this->cancelAtomic( $fname, $sectionId );
3874
3875 throw $e;
3876 }
3877 $this->endAtomic( $fname );
3878
3879 return $res;
3880 }
3881
3882 final public function begin( $fname = __METHOD__, $mode = self::TRANSACTION_EXPLICIT ) {
3883 static $modes = [ self::TRANSACTION_EXPLICIT, self::TRANSACTION_INTERNAL ];
3884 if ( !in_array( $mode, $modes, true ) ) {
3885 throw new DBUnexpectedError( $this, "$fname: invalid mode parameter '$mode'." );
3886 }
3887
3888 // Protect against mismatched atomic section, transaction nesting, and snapshot loss
3889 if ( $this->trxLevel ) {
3890 if ( $this->trxAtomicLevels ) {
3891 $levels = $this->flatAtomicSectionList();
3892 $msg = "$fname: Got explicit BEGIN while atomic section(s) $levels are open.";
3893 throw new DBUnexpectedError( $this, $msg );
3894 } elseif ( !$this->trxAutomatic ) {
3895 $msg = "$fname: Explicit transaction already active (from {$this->trxFname}).";
3896 throw new DBUnexpectedError( $this, $msg );
3897 } else {
3898 $msg = "$fname: Implicit transaction already active (from {$this->trxFname}).";
3899 throw new DBUnexpectedError( $this, $msg );
3900 }
3901 } elseif ( $this->getFlag( self::DBO_TRX ) && $mode !== self::TRANSACTION_INTERNAL ) {
3902 $msg = "$fname: Implicit transaction expected (DBO_TRX set).";
3903 throw new DBUnexpectedError( $this, $msg );
3904 }
3905
3906 $this->assertHasConnectionHandle();
3907
3908 $this->doBegin( $fname );
3909 $this->trxStatus = self::STATUS_TRX_OK;
3910 $this->trxStatusIgnoredCause = null;
3911 $this->trxAtomicCounter = 0;
3912 $this->trxTimestamp = microtime( true );
3913 $this->trxFname = $fname;
3914 $this->trxDoneWrites = false;
3915 $this->trxAutomaticAtomic = false;
3916 $this->trxAtomicLevels = [];
3917 $this->trxShortId = sprintf( '%06x', mt_rand( 0, 0xffffff ) );
3918 $this->trxWriteDuration = 0.0;
3919 $this->trxWriteQueryCount = 0;
3920 $this->trxWriteAffectedRows = 0;
3921 $this->trxWriteAdjDuration = 0.0;
3922 $this->trxWriteAdjQueryCount = 0;
3923 $this->trxWriteCallers = [];
3924 // First SELECT after BEGIN will establish the snapshot in REPEATABLE-READ.
3925 // Get an estimate of the replication lag before any such queries.
3926 $this->trxReplicaLag = null; // clear cached value first
3927 $this->trxReplicaLag = $this->getApproximateLagStatus()['lag'];
3928 // T147697: make explicitTrxActive() return true until begin() finishes. This way, no
3929 // caller will think its OK to muck around with the transaction just because startAtomic()
3930 // has not yet completed (e.g. setting trxAtomicLevels).
3931 $this->trxAutomatic = ( $mode === self::TRANSACTION_INTERNAL );
3932 }
3933
3934 /**
3935 * Issues the BEGIN command to the database server.
3936 *
3937 * @see Database::begin()
3938 * @param string $fname
3939 */
3940 protected function doBegin( $fname ) {
3941 $this->query( 'BEGIN', $fname );
3942 $this->trxLevel = 1;
3943 }
3944
3945 final public function commit( $fname = __METHOD__, $flush = self::FLUSHING_ONE ) {
3946 static $modes = [ self::FLUSHING_ONE, self::FLUSHING_ALL_PEERS, self::FLUSHING_INTERNAL ];
3947 if ( !in_array( $flush, $modes, true ) ) {
3948 throw new DBUnexpectedError( $this, "$fname: invalid flush parameter '$flush'." );
3949 }
3950
3951 if ( $this->trxLevel && $this->trxAtomicLevels ) {
3952 // There are still atomic sections open; this cannot be ignored
3953 $levels = $this->flatAtomicSectionList();
3954 throw new DBUnexpectedError(
3955 $this,
3956 "$fname: Got COMMIT while atomic sections $levels are still open."
3957 );
3958 }
3959
3960 if ( $flush === self::FLUSHING_INTERNAL || $flush === self::FLUSHING_ALL_PEERS ) {
3961 if ( !$this->trxLevel ) {
3962 return; // nothing to do
3963 } elseif ( !$this->trxAutomatic ) {
3964 throw new DBUnexpectedError(
3965 $this,
3966 "$fname: Flushing an explicit transaction, getting out of sync."
3967 );
3968 }
3969 } else {
3970 if ( !$this->trxLevel ) {
3971 $this->queryLogger->error(
3972 "$fname: No transaction to commit, something got out of sync." );
3973 return; // nothing to do
3974 } elseif ( $this->trxAutomatic ) {
3975 throw new DBUnexpectedError(
3976 $this,
3977 "$fname: Expected mass commit of all peer transactions (DBO_TRX set)."
3978 );
3979 }
3980 }
3981
3982 $this->assertHasConnectionHandle();
3983
3984 $this->runOnTransactionPreCommitCallbacks();
3985
3986 $writeTime = $this->pendingWriteQueryDuration( self::ESTIMATE_DB_APPLY );
3987 $this->doCommit( $fname );
3988 $this->trxStatus = self::STATUS_TRX_NONE;
3989
3990 if ( $this->trxDoneWrites ) {
3991 $this->lastWriteTime = microtime( true );
3992 $this->trxProfiler->transactionWritingOut(
3993 $this->server,
3994 $this->getDomainID(),
3995 $this->trxShortId,
3996 $writeTime,
3997 $this->trxWriteAffectedRows
3998 );
3999 }
4000
4001 // With FLUSHING_ALL_PEERS, callbacks will be explicitly run later
4002 if ( $flush !== self::FLUSHING_ALL_PEERS ) {
4003 $this->runOnTransactionIdleCallbacks( self::TRIGGER_COMMIT );
4004 $this->runTransactionListenerCallbacks( self::TRIGGER_COMMIT );
4005 }
4006 }
4007
4008 /**
4009 * Issues the COMMIT command to the database server.
4010 *
4011 * @see Database::commit()
4012 * @param string $fname
4013 */
4014 protected function doCommit( $fname ) {
4015 if ( $this->trxLevel ) {
4016 $this->query( 'COMMIT', $fname );
4017 $this->trxLevel = 0;
4018 }
4019 }
4020
4021 final public function rollback( $fname = __METHOD__, $flush = '' ) {
4022 $trxActive = $this->trxLevel;
4023
4024 if ( $flush !== self::FLUSHING_INTERNAL && $flush !== self::FLUSHING_ALL_PEERS ) {
4025 if ( $this->getFlag( self::DBO_TRX ) ) {
4026 throw new DBUnexpectedError(
4027 $this,
4028 "$fname: Expected mass rollback of all peer transactions (DBO_TRX set)."
4029 );
4030 }
4031 }
4032
4033 if ( $trxActive ) {
4034 $this->assertHasConnectionHandle();
4035
4036 $this->doRollback( $fname );
4037 $this->trxStatus = self::STATUS_TRX_NONE;
4038 $this->trxAtomicLevels = [];
4039 // Estimate the RTT via a query now that trxStatus is OK
4040 $writeTime = $this->pingAndCalculateLastTrxApplyTime();
4041
4042 if ( $this->trxDoneWrites ) {
4043 $this->trxProfiler->transactionWritingOut(
4044 $this->server,
4045 $this->getDomainID(),
4046 $this->trxShortId,
4047 $writeTime,
4048 $this->trxWriteAffectedRows
4049 );
4050 }
4051 }
4052
4053 // Clear any commit-dependant callbacks. They might even be present
4054 // only due to transaction rounds, with no SQL transaction being active
4055 $this->trxIdleCallbacks = [];
4056 $this->trxPreCommitCallbacks = [];
4057
4058 // With FLUSHING_ALL_PEERS, callbacks will be explicitly run later
4059 if ( $trxActive && $flush !== self::FLUSHING_ALL_PEERS ) {
4060 try {
4061 $this->runOnTransactionIdleCallbacks( self::TRIGGER_ROLLBACK );
4062 } catch ( Exception $e ) {
4063 // already logged; finish and let LoadBalancer move on during mass-rollback
4064 }
4065 try {
4066 $this->runTransactionListenerCallbacks( self::TRIGGER_ROLLBACK );
4067 } catch ( Exception $e ) {
4068 // already logged; let LoadBalancer move on during mass-rollback
4069 }
4070
4071 $this->affectedRowCount = 0; // for the sake of consistency
4072 }
4073 }
4074
4075 /**
4076 * Issues the ROLLBACK command to the database server.
4077 *
4078 * @see Database::rollback()
4079 * @param string $fname
4080 */
4081 protected function doRollback( $fname ) {
4082 if ( $this->trxLevel ) {
4083 # Disconnects cause rollback anyway, so ignore those errors
4084 $ignoreErrors = true;
4085 $this->query( 'ROLLBACK', $fname, $ignoreErrors );
4086 $this->trxLevel = 0;
4087 }
4088 }
4089
4090 public function flushSnapshot( $fname = __METHOD__ ) {
4091 if ( $this->writesOrCallbacksPending() || $this->explicitTrxActive() ) {
4092 // This only flushes transactions to clear snapshots, not to write data
4093 $fnames = implode( ', ', $this->pendingWriteAndCallbackCallers() );
4094 throw new DBUnexpectedError(
4095 $this,
4096 "$fname: Cannot flush snapshot because writes are pending ($fnames)."
4097 );
4098 }
4099
4100 $this->commit( $fname, self::FLUSHING_INTERNAL );
4101 }
4102
4103 public function explicitTrxActive() {
4104 return $this->trxLevel && ( $this->trxAtomicLevels || !$this->trxAutomatic );
4105 }
4106
4107 public function duplicateTableStructure(
4108 $oldName, $newName, $temporary = false, $fname = __METHOD__
4109 ) {
4110 throw new RuntimeException( __METHOD__ . ' is not implemented in descendant class' );
4111 }
4112
4113 public function listTables( $prefix = null, $fname = __METHOD__ ) {
4114 throw new RuntimeException( __METHOD__ . ' is not implemented in descendant class' );
4115 }
4116
4117 public function listViews( $prefix = null, $fname = __METHOD__ ) {
4118 throw new RuntimeException( __METHOD__ . ' is not implemented in descendant class' );
4119 }
4120
4121 public function timestamp( $ts = 0 ) {
4122 $t = new ConvertibleTimestamp( $ts );
4123 // Let errors bubble up to avoid putting garbage in the DB
4124 return $t->getTimestamp( TS_MW );
4125 }
4126
4127 public function timestampOrNull( $ts = null ) {
4128 if ( is_null( $ts ) ) {
4129 return null;
4130 } else {
4131 return $this->timestamp( $ts );
4132 }
4133 }
4134
4135 public function affectedRows() {
4136 return ( $this->affectedRowCount === null )
4137 ? $this->fetchAffectedRowCount() // default to driver value
4138 : $this->affectedRowCount;
4139 }
4140
4141 /**
4142 * @return int Number of retrieved rows according to the driver
4143 */
4144 abstract protected function fetchAffectedRowCount();
4145
4146 /**
4147 * Take the result from a query, and wrap it in a ResultWrapper if
4148 * necessary. Boolean values are passed through as is, to indicate success
4149 * of write queries or failure.
4150 *
4151 * Once upon a time, Database::query() returned a bare MySQL result
4152 * resource, and it was necessary to call this function to convert it to
4153 * a wrapper. Nowadays, raw database objects are never exposed to external
4154 * callers, so this is unnecessary in external code.
4155 *
4156 * @param bool|ResultWrapper|resource $result
4157 * @return bool|ResultWrapper
4158 */
4159 protected function resultObject( $result ) {
4160 if ( !$result ) {
4161 return false;
4162 } elseif ( $result instanceof ResultWrapper ) {
4163 return $result;
4164 } elseif ( $result === true ) {
4165 // Successful write query
4166 return $result;
4167 } else {
4168 return new ResultWrapper( $this, $result );
4169 }
4170 }
4171
4172 public function ping( &$rtt = null ) {
4173 // Avoid hitting the server if it was hit recently
4174 if ( $this->isOpen() && ( microtime( true ) - $this->lastPing ) < self::PING_TTL ) {
4175 if ( !func_num_args() || $this->rttEstimate > 0 ) {
4176 $rtt = $this->rttEstimate;
4177 return true; // don't care about $rtt
4178 }
4179 }
4180
4181 // This will reconnect if possible or return false if not
4182 $this->clearFlag( self::DBO_TRX, self::REMEMBER_PRIOR );
4183 $ok = ( $this->query( self::PING_QUERY, __METHOD__, true ) !== false );
4184 $this->restoreFlags( self::RESTORE_PRIOR );
4185
4186 if ( $ok ) {
4187 $rtt = $this->rttEstimate;
4188 }
4189
4190 return $ok;
4191 }
4192
4193 /**
4194 * Close any existing (dead) database connection and open a new connection
4195 *
4196 * @param string $fname
4197 * @return bool True if new connection is opened successfully, false if error
4198 */
4199 protected function replaceLostConnection( $fname ) {
4200 $this->closeConnection();
4201 $this->opened = false;
4202 $this->conn = false;
4203
4204 $this->handleSessionLossPreconnect();
4205
4206 try {
4207 $this->open(
4208 $this->server,
4209 $this->user,
4210 $this->password,
4211 $this->getDBname(),
4212 $this->dbSchema(),
4213 $this->tablePrefix()
4214 );
4215 $this->lastPing = microtime( true );
4216 $ok = true;
4217
4218 $this->connLogger->warning(
4219 $fname . ': lost connection to {dbserver}; reconnected',
4220 [
4221 'dbserver' => $this->getServer(),
4222 'trace' => ( new RuntimeException() )->getTraceAsString()
4223 ]
4224 );
4225 } catch ( DBConnectionError $e ) {
4226 $ok = false;
4227
4228 $this->connLogger->error(
4229 $fname . ': lost connection to {dbserver} permanently',
4230 [ 'dbserver' => $this->getServer() ]
4231 );
4232 }
4233
4234 $this->handleSessionLossPostconnect();
4235
4236 return $ok;
4237 }
4238
4239 public function getSessionLagStatus() {
4240 return $this->getRecordedTransactionLagStatus() ?: $this->getApproximateLagStatus();
4241 }
4242
4243 /**
4244 * Get the replica DB lag when the current transaction started
4245 *
4246 * This is useful when transactions might use snapshot isolation
4247 * (e.g. REPEATABLE-READ in innodb), so the "real" lag of that data
4248 * is this lag plus transaction duration. If they don't, it is still
4249 * safe to be pessimistic. This returns null if there is no transaction.
4250 *
4251 * This returns null if the lag status for this transaction was not yet recorded.
4252 *
4253 * @return array|null ('lag': seconds or false on error, 'since': UNIX timestamp of BEGIN)
4254 * @since 1.27
4255 */
4256 final protected function getRecordedTransactionLagStatus() {
4257 return ( $this->trxLevel && $this->trxReplicaLag !== null )
4258 ? [ 'lag' => $this->trxReplicaLag, 'since' => $this->trxTimestamp() ]
4259 : null;
4260 }
4261
4262 /**
4263 * Get a replica DB lag estimate for this server
4264 *
4265 * @return array ('lag': seconds or false on error, 'since': UNIX timestamp of estimate)
4266 * @since 1.27
4267 */
4268 protected function getApproximateLagStatus() {
4269 return [
4270 'lag' => $this->getLBInfo( 'replica' ) ? $this->getLag() : 0,
4271 'since' => microtime( true )
4272 ];
4273 }
4274
4275 /**
4276 * Merge the result of getSessionLagStatus() for several DBs
4277 * using the most pessimistic values to estimate the lag of
4278 * any data derived from them in combination
4279 *
4280 * This is information is useful for caching modules
4281 *
4282 * @see WANObjectCache::set()
4283 * @see WANObjectCache::getWithSetCallback()
4284 *
4285 * @param IDatabase $db1
4286 * @param IDatabase|null $db2 [optional]
4287 * @return array Map of values:
4288 * - lag: highest lag of any of the DBs or false on error (e.g. replication stopped)
4289 * - since: oldest UNIX timestamp of any of the DB lag estimates
4290 * - pending: whether any of the DBs have uncommitted changes
4291 * @throws DBError
4292 * @since 1.27
4293 */
4294 public static function getCacheSetOptions( IDatabase $db1, IDatabase $db2 = null ) {
4295 $res = [ 'lag' => 0, 'since' => INF, 'pending' => false ];
4296 foreach ( func_get_args() as $db ) {
4297 /** @var IDatabase $db */
4298 $status = $db->getSessionLagStatus();
4299 if ( $status['lag'] === false ) {
4300 $res['lag'] = false;
4301 } elseif ( $res['lag'] !== false ) {
4302 $res['lag'] = max( $res['lag'], $status['lag'] );
4303 }
4304 $res['since'] = min( $res['since'], $status['since'] );
4305 $res['pending'] = $res['pending'] ?: $db->writesPending();
4306 }
4307
4308 return $res;
4309 }
4310
4311 public function getLag() {
4312 return 0;
4313 }
4314
4315 public function maxListLen() {
4316 return 0;
4317 }
4318
4319 public function encodeBlob( $b ) {
4320 return $b;
4321 }
4322
4323 public function decodeBlob( $b ) {
4324 if ( $b instanceof Blob ) {
4325 $b = $b->fetch();
4326 }
4327 return $b;
4328 }
4329
4330 public function setSessionOptions( array $options ) {
4331 }
4332
4333 public function sourceFile(
4334 $filename,
4335 callable $lineCallback = null,
4336 callable $resultCallback = null,
4337 $fname = false,
4338 callable $inputCallback = null
4339 ) {
4340 Wikimedia\suppressWarnings();
4341 $fp = fopen( $filename, 'r' );
4342 Wikimedia\restoreWarnings();
4343
4344 if ( $fp === false ) {
4345 throw new RuntimeException( "Could not open \"{$filename}\".\n" );
4346 }
4347
4348 if ( !$fname ) {
4349 $fname = __METHOD__ . "( $filename )";
4350 }
4351
4352 try {
4353 $error = $this->sourceStream(
4354 $fp, $lineCallback, $resultCallback, $fname, $inputCallback );
4355 } catch ( Exception $e ) {
4356 fclose( $fp );
4357 throw $e;
4358 }
4359
4360 fclose( $fp );
4361
4362 return $error;
4363 }
4364
4365 public function setSchemaVars( $vars ) {
4366 $this->schemaVars = $vars;
4367 }
4368
4369 public function sourceStream(
4370 $fp,
4371 callable $lineCallback = null,
4372 callable $resultCallback = null,
4373 $fname = __METHOD__,
4374 callable $inputCallback = null
4375 ) {
4376 $delimiterReset = new ScopedCallback(
4377 function ( $delimiter ) {
4378 $this->delimiter = $delimiter;
4379 },
4380 [ $this->delimiter ]
4381 );
4382 $cmd = '';
4383
4384 while ( !feof( $fp ) ) {
4385 if ( $lineCallback ) {
4386 call_user_func( $lineCallback );
4387 }
4388
4389 $line = trim( fgets( $fp ) );
4390
4391 if ( $line == '' ) {
4392 continue;
4393 }
4394
4395 if ( $line[0] == '-' && $line[1] == '-' ) {
4396 continue;
4397 }
4398
4399 if ( $cmd != '' ) {
4400 $cmd .= ' ';
4401 }
4402
4403 $done = $this->streamStatementEnd( $cmd, $line );
4404
4405 $cmd .= "$line\n";
4406
4407 if ( $done || feof( $fp ) ) {
4408 $cmd = $this->replaceVars( $cmd );
4409
4410 if ( $inputCallback ) {
4411 $callbackResult = $inputCallback( $cmd );
4412
4413 if ( is_string( $callbackResult ) || !$callbackResult ) {
4414 $cmd = $callbackResult;
4415 }
4416 }
4417
4418 if ( $cmd ) {
4419 $res = $this->query( $cmd, $fname );
4420
4421 if ( $resultCallback ) {
4422 $resultCallback( $res, $this );
4423 }
4424
4425 if ( $res === false ) {
4426 $err = $this->lastError();
4427
4428 return "Query \"{$cmd}\" failed with error code \"$err\".\n";
4429 }
4430 }
4431 $cmd = '';
4432 }
4433 }
4434
4435 ScopedCallback::consume( $delimiterReset );
4436 return true;
4437 }
4438
4439 /**
4440 * Called by sourceStream() to check if we've reached a statement end
4441 *
4442 * @param string &$sql SQL assembled so far
4443 * @param string &$newLine New line about to be added to $sql
4444 * @return bool Whether $newLine contains end of the statement
4445 */
4446 public function streamStatementEnd( &$sql, &$newLine ) {
4447 if ( $this->delimiter ) {
4448 $prev = $newLine;
4449 $newLine = preg_replace(
4450 '/' . preg_quote( $this->delimiter, '/' ) . '$/', '', $newLine );
4451 if ( $newLine != $prev ) {
4452 return true;
4453 }
4454 }
4455
4456 return false;
4457 }
4458
4459 /**
4460 * Database independent variable replacement. Replaces a set of variables
4461 * in an SQL statement with their contents as given by $this->getSchemaVars().
4462 *
4463 * Supports '{$var}' `{$var}` and / *$var* / (without the spaces) style variables.
4464 *
4465 * - '{$var}' should be used for text and is passed through the database's
4466 * addQuotes method.
4467 * - `{$var}` should be used for identifiers (e.g. table and database names).
4468 * It is passed through the database's addIdentifierQuotes method which
4469 * can be overridden if the database uses something other than backticks.
4470 * - / *_* / or / *$wgDBprefix* / passes the name that follows through the
4471 * database's tableName method.
4472 * - / *i* / passes the name that follows through the database's indexName method.
4473 * - In all other cases, / *$var* / is left unencoded. Except for table options,
4474 * its use should be avoided. In 1.24 and older, string encoding was applied.
4475 *
4476 * @param string $ins SQL statement to replace variables in
4477 * @return string The new SQL statement with variables replaced
4478 */
4479 protected function replaceVars( $ins ) {
4480 $vars = $this->getSchemaVars();
4481 return preg_replace_callback(
4482 '!
4483 /\* (\$wgDBprefix|[_i]) \*/ (\w*) | # 1-2. tableName, indexName
4484 \'\{\$ (\w+) }\' | # 3. addQuotes
4485 `\{\$ (\w+) }` | # 4. addIdentifierQuotes
4486 /\*\$ (\w+) \*/ # 5. leave unencoded
4487 !x',
4488 function ( $m ) use ( $vars ) {
4489 // Note: Because of <https://bugs.php.net/bug.php?id=51881>,
4490 // check for both nonexistent keys *and* the empty string.
4491 if ( isset( $m[1] ) && $m[1] !== '' ) {
4492 if ( $m[1] === 'i' ) {
4493 return $this->indexName( $m[2] );
4494 } else {
4495 return $this->tableName( $m[2] );
4496 }
4497 } elseif ( isset( $m[3] ) && $m[3] !== '' && array_key_exists( $m[3], $vars ) ) {
4498 return $this->addQuotes( $vars[$m[3]] );
4499 } elseif ( isset( $m[4] ) && $m[4] !== '' && array_key_exists( $m[4], $vars ) ) {
4500 return $this->addIdentifierQuotes( $vars[$m[4]] );
4501 } elseif ( isset( $m[5] ) && $m[5] !== '' && array_key_exists( $m[5], $vars ) ) {
4502 return $vars[$m[5]];
4503 } else {
4504 return $m[0];
4505 }
4506 },
4507 $ins
4508 );
4509 }
4510
4511 /**
4512 * Get schema variables. If none have been set via setSchemaVars(), then
4513 * use some defaults from the current object.
4514 *
4515 * @return array
4516 */
4517 protected function getSchemaVars() {
4518 if ( $this->schemaVars ) {
4519 return $this->schemaVars;
4520 } else {
4521 return $this->getDefaultSchemaVars();
4522 }
4523 }
4524
4525 /**
4526 * Get schema variables to use if none have been set via setSchemaVars().
4527 *
4528 * Override this in derived classes to provide variables for tables.sql
4529 * and SQL patch files.
4530 *
4531 * @return array
4532 */
4533 protected function getDefaultSchemaVars() {
4534 return [];
4535 }
4536
4537 public function lockIsFree( $lockName, $method ) {
4538 // RDBMs methods for checking named locks may or may not count this thread itself.
4539 // In MySQL, IS_FREE_LOCK() returns 0 if the thread already has the lock. This is
4540 // the behavior choosen by the interface for this method.
4541 return !isset( $this->namedLocksHeld[$lockName] );
4542 }
4543
4544 public function lock( $lockName, $method, $timeout = 5 ) {
4545 $this->namedLocksHeld[$lockName] = 1;
4546
4547 return true;
4548 }
4549
4550 public function unlock( $lockName, $method ) {
4551 unset( $this->namedLocksHeld[$lockName] );
4552
4553 return true;
4554 }
4555
4556 public function getScopedLockAndFlush( $lockKey, $fname, $timeout ) {
4557 if ( $this->writesOrCallbacksPending() ) {
4558 // This only flushes transactions to clear snapshots, not to write data
4559 $fnames = implode( ', ', $this->pendingWriteAndCallbackCallers() );
4560 throw new DBUnexpectedError(
4561 $this,
4562 "$fname: Cannot flush pre-lock snapshot because writes are pending ($fnames)."
4563 );
4564 }
4565
4566 if ( !$this->lock( $lockKey, $fname, $timeout ) ) {
4567 return null;
4568 }
4569
4570 $unlocker = new ScopedCallback( function () use ( $lockKey, $fname ) {
4571 if ( $this->trxLevel() ) {
4572 // There is a good chance an exception was thrown, causing any early return
4573 // from the caller. Let any error handler get a chance to issue rollback().
4574 // If there isn't one, let the error bubble up and trigger server-side rollback.
4575 $this->onTransactionResolution(
4576 function () use ( $lockKey, $fname ) {
4577 $this->unlock( $lockKey, $fname );
4578 },
4579 $fname
4580 );
4581 } else {
4582 $this->unlock( $lockKey, $fname );
4583 }
4584 } );
4585
4586 $this->commit( $fname, self::FLUSHING_INTERNAL );
4587
4588 return $unlocker;
4589 }
4590
4591 public function namedLocksEnqueue() {
4592 return false;
4593 }
4594
4595 public function tableLocksHaveTransactionScope() {
4596 return true;
4597 }
4598
4599 final public function lockTables( array $read, array $write, $method ) {
4600 if ( $this->writesOrCallbacksPending() ) {
4601 throw new DBUnexpectedError( $this, "Transaction writes or callbacks still pending." );
4602 }
4603
4604 if ( $this->tableLocksHaveTransactionScope() ) {
4605 $this->startAtomic( $method );
4606 }
4607
4608 return $this->doLockTables( $read, $write, $method );
4609 }
4610
4611 /**
4612 * Helper function for lockTables() that handles the actual table locking
4613 *
4614 * @param array $read Array of tables to lock for read access
4615 * @param array $write Array of tables to lock for write access
4616 * @param string $method Name of caller
4617 * @return true
4618 */
4619 protected function doLockTables( array $read, array $write, $method ) {
4620 return true;
4621 }
4622
4623 final public function unlockTables( $method ) {
4624 if ( $this->tableLocksHaveTransactionScope() ) {
4625 $this->endAtomic( $method );
4626
4627 return true; // locks released on COMMIT/ROLLBACK
4628 }
4629
4630 return $this->doUnlockTables( $method );
4631 }
4632
4633 /**
4634 * Helper function for unlockTables() that handles the actual table unlocking
4635 *
4636 * @param string $method Name of caller
4637 * @return true
4638 */
4639 protected function doUnlockTables( $method ) {
4640 return true;
4641 }
4642
4643 /**
4644 * Delete a table
4645 * @param string $tableName
4646 * @param string $fName
4647 * @return bool|ResultWrapper
4648 * @since 1.18
4649 */
4650 public function dropTable( $tableName, $fName = __METHOD__ ) {
4651 if ( !$this->tableExists( $tableName, $fName ) ) {
4652 return false;
4653 }
4654 $sql = "DROP TABLE " . $this->tableName( $tableName ) . " CASCADE";
4655
4656 return $this->query( $sql, $fName );
4657 }
4658
4659 public function getInfinity() {
4660 return 'infinity';
4661 }
4662
4663 public function encodeExpiry( $expiry ) {
4664 return ( $expiry == '' || $expiry == 'infinity' || $expiry == $this->getInfinity() )
4665 ? $this->getInfinity()
4666 : $this->timestamp( $expiry );
4667 }
4668
4669 public function decodeExpiry( $expiry, $format = TS_MW ) {
4670 if ( $expiry == '' || $expiry == 'infinity' || $expiry == $this->getInfinity() ) {
4671 return 'infinity';
4672 }
4673
4674 return ConvertibleTimestamp::convert( $format, $expiry );
4675 }
4676
4677 public function setBigSelects( $value = true ) {
4678 // no-op
4679 }
4680
4681 public function isReadOnly() {
4682 return ( $this->getReadOnlyReason() !== false );
4683 }
4684
4685 /**
4686 * @return string|bool Reason this DB is read-only or false if it is not
4687 */
4688 protected function getReadOnlyReason() {
4689 $reason = $this->getLBInfo( 'readOnlyReason' );
4690
4691 return is_string( $reason ) ? $reason : false;
4692 }
4693
4694 public function setTableAliases( array $aliases ) {
4695 $this->tableAliases = $aliases;
4696 }
4697
4698 public function setIndexAliases( array $aliases ) {
4699 $this->indexAliases = $aliases;
4700 }
4701
4702 /**
4703 * @param int $field
4704 * @param int $flags
4705 * @return bool
4706 */
4707 protected function hasFlags( $field, $flags ) {
4708 return ( ( $field & $flags ) === $flags );
4709 }
4710
4711 /**
4712 * Get the underlying binding connection handle
4713 *
4714 * Makes sure the connection resource is set (disconnects and ping() failure can unset it).
4715 * This catches broken callers than catch and ignore disconnection exceptions.
4716 * Unlike checking isOpen(), this is safe to call inside of open().
4717 *
4718 * @return mixed
4719 * @throws DBUnexpectedError
4720 * @since 1.26
4721 */
4722 protected function getBindingHandle() {
4723 if ( !$this->conn ) {
4724 throw new DBUnexpectedError(
4725 $this,
4726 'DB connection was already closed or the connection dropped.'
4727 );
4728 }
4729
4730 return $this->conn;
4731 }
4732
4733 /**
4734 * @since 1.19
4735 * @return string
4736 */
4737 public function __toString() {
4738 return (string)$this->conn;
4739 }
4740
4741 /**
4742 * Make sure that copies do not share the same client binding handle
4743 * @throws DBConnectionError
4744 */
4745 public function __clone() {
4746 $this->connLogger->warning(
4747 "Cloning " . static::class . " is not recommended; forking connection:\n" .
4748 ( new RuntimeException() )->getTraceAsString()
4749 );
4750
4751 if ( $this->isOpen() ) {
4752 // Open a new connection resource without messing with the old one
4753 $this->opened = false;
4754 $this->conn = false;
4755 $this->trxEndCallbacks = []; // don't copy
4756 $this->handleSessionLossPreconnect(); // no trx or locks anymore
4757 $this->open(
4758 $this->server,
4759 $this->user,
4760 $this->password,
4761 $this->getDBname(),
4762 $this->dbSchema(),
4763 $this->tablePrefix()
4764 );
4765 $this->lastPing = microtime( true );
4766 }
4767 }
4768
4769 /**
4770 * Called by serialize. Throw an exception when DB connection is serialized.
4771 * This causes problems on some database engines because the connection is
4772 * not restored on unserialize.
4773 */
4774 public function __sleep() {
4775 throw new RuntimeException( 'Database serialization may cause problems, since ' .
4776 'the connection is not restored on wakeup.' );
4777 }
4778
4779 /**
4780 * Run a few simple sanity checks and close dangling connections
4781 */
4782 public function __destruct() {
4783 if ( $this->trxLevel && $this->trxDoneWrites ) {
4784 trigger_error( "Uncommitted DB writes (transaction from {$this->trxFname})." );
4785 }
4786
4787 $danglingWriters = $this->pendingWriteAndCallbackCallers();
4788 if ( $danglingWriters ) {
4789 $fnames = implode( ', ', $danglingWriters );
4790 trigger_error( "DB transaction writes or callbacks still pending ($fnames)." );
4791 }
4792
4793 if ( $this->conn ) {
4794 // Avoid connection leaks for sanity. Normally, resources close at script completion.
4795 // The connection might already be closed in zend/hhvm by now, so suppress warnings.
4796 Wikimedia\suppressWarnings();
4797 $this->closeConnection();
4798 Wikimedia\restoreWarnings();
4799 $this->conn = false;
4800 $this->opened = false;
4801 }
4802 }
4803 }
4804
4805 /**
4806 * @deprecated since 1.28
4807 */
4808 class_alias( Database::class, 'DatabaseBase' );
4809
4810 /**
4811 * @deprecated since 1.29
4812 */
4813 class_alias( Database::class, 'Database' );
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