3 * @defgroup Database Database
5 * This file deals with database interface functions
6 * and query specifics/optimisations.
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.
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.
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
26 namespace Wikimedia\Rdbms
;
28 use Psr\Log\LoggerAwareInterface
;
29 use Psr\Log\LoggerInterface
;
30 use Psr\Log\NullLogger
;
31 use Wikimedia\ScopedCallback
;
32 use Wikimedia\Timestamp\ConvertibleTimestamp
;
37 use InvalidArgumentException
;
38 use UnexpectedValueException
;
43 * Relational database abstraction object
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;
56 /** How long before it is worth doing a dummy query to test the connection */
58 const PING_QUERY
= 'SELECT 1 AS ping';
60 const TINY_WRITE_SEC
= 0.010;
61 const SLOW_WRITE_SEC
= 0.500;
62 const SMALL_WRITE_ROWS
= 100;
64 /** @var string Lock granularity is on the level of the entire database */
65 const ATTR_DB_LEVEL_LOCKING
= 'db-level-locking';
66 /** @var string The SCHEMA keyword refers to a grouping of tables in a database */
67 const ATTR_SCHEMAS_AS_TABLE_GROUPS
= 'supports-schemas';
69 /** @var int New Database instance will not be connected yet when returned */
70 const NEW_UNCONNECTED
= 0;
71 /** @var int New Database instance will already be connected when returned */
72 const NEW_CONNECTED
= 1;
74 /** @var string The last SQL query attempted */
75 private $lastQuery = '';
76 /** @var float|bool UNIX timestamp of last write query */
77 private $lastWriteTime = false;
78 /** @var string|bool */
79 private $lastPhpError = false;
81 /** @var string Server that this instance is currently connected to */
83 /** @var string User that this instance is currently connected under the name of */
85 /** @var string Password used to establish the current connection */
87 /** @var array[] Map of (table => (dbname, schema, prefix) map) */
88 protected $tableAliases = [];
89 /** @var string[] Map of (index alias => index) */
90 protected $indexAliases = [];
91 /** @var bool Whether this PHP instance is for a CLI script */
93 /** @var string Agent name for query profiling */
95 /** @var array Parameters used by initConnection() to establish a connection */
96 protected $connectionParams = [];
97 /** @var BagOStuff APC cache */
99 /** @var LoggerInterface */
100 protected $connLogger;
101 /** @var LoggerInterface */
102 protected $queryLogger;
103 /** @var callable Error logging callback */
104 protected $errorLogger;
105 /** @var callable Deprecation logging callback */
106 protected $deprecationLogger;
108 /** @var object|resource|null Database connection */
109 protected $conn = null;
111 protected $opened = false;
113 /** @var array[] List of (callable, method name, atomic section id) */
114 protected $trxIdleCallbacks = [];
115 /** @var array[] List of (callable, method name, atomic section id) */
116 protected $trxPreCommitCallbacks = [];
117 /** @var array[] List of (callable, method name, atomic section id) */
118 protected $trxEndCallbacks = [];
119 /** @var callable[] Map of (name => callable) */
120 protected $trxRecurringCallbacks = [];
121 /** @var bool Whether to suppress triggering of transaction end callbacks */
122 protected $trxEndCallbacksSuppressed = false;
127 protected $lbInfo = [];
128 /** @var array|bool */
129 protected $schemaVars = false;
131 protected $sessionVars = [];
132 /** @var array|null */
133 protected $preparedArgs;
134 /** @var string|bool|null Stashed value of html_errors INI setting */
135 protected $htmlErrors;
137 protected $delimiter = ';';
138 /** @var DatabaseDomain */
139 protected $currentDomain;
140 /** @var integer|null Rows affected by the last query to query() or its CRUD wrappers */
141 protected $affectedRowCount;
144 * @var int Transaction status
146 protected $trxStatus = self
::STATUS_TRX_NONE
;
148 * @var Exception|null The last error that caused the status to become STATUS_TRX_ERROR
150 protected $trxStatusCause;
152 * @var array|null If wasKnownStatementRollbackError() prevented trxStatus from being set,
153 * the relevant details are stored here.
155 protected $trxStatusIgnoredCause;
157 * Either 1 if a transaction is active or 0 otherwise.
158 * The other Trx fields may not be meaningfull if this is 0.
162 protected $trxLevel = 0;
164 * Either a short hexidecimal string if a transaction is active or ""
167 * @see Database::trxLevel
169 protected $trxShortId = '';
171 * The UNIX time that the transaction started. Callers can assume that if
172 * snapshot isolation is used, then the data is *at least* up to date to that
173 * point (possibly more up-to-date since the first SELECT defines the snapshot).
176 * @see Database::trxLevel
178 private $trxTimestamp = null;
179 /** @var float Lag estimate at the time of BEGIN */
180 private $trxReplicaLag = null;
182 * Remembers the function name given for starting the most recent transaction via begin().
183 * Used to provide additional context for error reporting.
186 * @see Database::trxLevel
188 private $trxFname = null;
190 * Record if possible write queries were done in the last transaction started
193 * @see Database::trxLevel
195 private $trxDoneWrites = false;
197 * Record if the current transaction was started implicitly due to DBO_TRX being set.
200 * @see Database::trxLevel
202 private $trxAutomatic = false;
204 * Counter for atomic savepoint identifiers. Reset when a new transaction begins.
208 private $trxAtomicCounter = 0;
210 * Array of levels of atomicity within transactions
212 * @var array List of (name, unique ID, savepoint ID)
214 private $trxAtomicLevels = [];
216 * Record if the current transaction was started implicitly by Database::startAtomic
220 private $trxAutomaticAtomic = false;
222 * Track the write query callers of the current transaction
226 private $trxWriteCallers = [];
228 * @var float Seconds spent in write queries for the current transaction
230 private $trxWriteDuration = 0.0;
232 * @var int Number of write queries for the current transaction
234 private $trxWriteQueryCount = 0;
236 * @var int Number of rows affected by write queries for the current transaction
238 private $trxWriteAffectedRows = 0;
240 * @var float Like trxWriteQueryCount but excludes lock-bound, easy to replicate, queries
242 private $trxWriteAdjDuration = 0.0;
244 * @var int Number of write queries counted in trxWriteAdjDuration
246 private $trxWriteAdjQueryCount = 0;
248 * @var float RTT time estimate
250 private $rttEstimate = 0.0;
252 /** @var array Map of (name => 1) for locks obtained via lock() */
253 private $namedLocksHeld = [];
254 /** @var array Map of (table name => 1) for TEMPORARY tables */
255 protected $sessionTempTables = [];
257 /** @var IDatabase|null Lazy handle to the master DB this server replicates from */
258 private $lazyMasterHandle;
260 /** @var float UNIX timestamp */
261 protected $lastPing = 0.0;
263 /** @var int[] Prior flags member variable values */
264 private $priorFlags = [];
266 /** @var callable|null */
268 /** @var TransactionProfiler */
269 protected $trxProfiler;
272 protected $nonNativeInsertSelectBatchSize = 10000;
274 /** @var string Idiom used when a cancelable atomic section started the transaction */
275 private static $NOT_APPLICABLE = 'n/a';
276 /** @var string Prefix to the atomic section counter used to make savepoint IDs */
277 private static $SAVEPOINT_PREFIX = 'wikimedia_rdbms_atomic';
279 /** @var int Transaction is in a error state requiring a full or savepoint rollback */
280 const STATUS_TRX_ERROR
= 1;
281 /** @var int Transaction is active and in a normal state */
282 const STATUS_TRX_OK
= 2;
283 /** @var int No transaction is active */
284 const STATUS_TRX_NONE
= 3;
286 /** @var int Writes to this temporary table do not affect lastDoneWrites() */
287 const TEMP_NORMAL
= 1;
288 /** @var int Writes to this temporary table effect lastDoneWrites() */
289 const TEMP_PSEUDO_PERMANENT
= 2;
292 * @note exceptions for missing libraries/drivers should be thrown in initConnection()
293 * @param array $params Parameters passed from Database::factory()
295 protected function __construct( array $params ) {
296 foreach ( [ 'host', 'user', 'password', 'dbname', 'schema', 'tablePrefix' ] as $name ) {
297 $this->connectionParams
[$name] = $params[$name];
300 $this->cliMode
= $params['cliMode'];
301 // Agent name is added to SQL queries in a comment, so make sure it can't break out
302 $this->agent
= str_replace( '/', '-', $params['agent'] );
304 $this->flags
= $params['flags'];
305 if ( $this->flags
& self
::DBO_DEFAULT
) {
306 if ( $this->cliMode
) {
307 $this->flags
&= ~self
::DBO_TRX
;
309 $this->flags |
= self
::DBO_TRX
;
312 // Disregard deprecated DBO_IGNORE flag (T189999)
313 $this->flags
&= ~self
::DBO_IGNORE
;
315 $this->sessionVars
= $params['variables'];
317 $this->srvCache
= $params['srvCache'] ??
new HashBagOStuff();
319 $this->profiler
= is_callable( $params['profiler'] ) ?
$params['profiler'] : null;
320 $this->trxProfiler
= $params['trxProfiler'];
321 $this->connLogger
= $params['connLogger'];
322 $this->queryLogger
= $params['queryLogger'];
323 $this->errorLogger
= $params['errorLogger'];
324 $this->deprecationLogger
= $params['deprecationLogger'];
326 if ( isset( $params['nonNativeInsertSelectBatchSize'] ) ) {
327 $this->nonNativeInsertSelectBatchSize
= $params['nonNativeInsertSelectBatchSize'];
330 // Set initial dummy domain until open() sets the final DB/prefix
331 $this->currentDomain
= new DatabaseDomain(
332 $params['dbname'] != '' ?
$params['dbname'] : null,
333 $params['schema'] != '' ?
$params['schema'] : null,
334 $params['tablePrefix']
339 * Initialize the connection to the database over the wire (or to local files)
341 * @throws LogicException
342 * @throws InvalidArgumentException
343 * @throws DBConnectionError
346 final public function initConnection() {
347 if ( $this->isOpen() ) {
348 throw new LogicException( __METHOD__
. ': already connected.' );
350 // Establish the connection
351 $this->doInitConnection();
355 * Actually connect to the database over the wire (or to local files)
357 * @throws InvalidArgumentException
358 * @throws DBConnectionError
361 protected function doInitConnection() {
362 if ( strlen( $this->connectionParams
['user'] ) ) {
364 $this->connectionParams
['host'],
365 $this->connectionParams
['user'],
366 $this->connectionParams
['password'],
367 $this->connectionParams
['dbname'],
368 $this->connectionParams
['schema'],
369 $this->connectionParams
['tablePrefix']
372 throw new InvalidArgumentException( "No database user provided." );
377 * Open a new connection to the database (closing any existing one)
379 * @param string $server Database server host
380 * @param string $user Database user name
381 * @param string $password Database user password
382 * @param string $dbName Database name
383 * @param string|null $schema Database schema name
384 * @param string $tablePrefix Table prefix
386 * @throws DBConnectionError
388 abstract protected function open( $server, $user, $password, $dbName, $schema, $tablePrefix );
391 * Construct a Database subclass instance given a database type and parameters
393 * This also connects to the database immediately upon object construction
395 * @param string $dbType A possible DB type (sqlite, mysql, postgres,...)
396 * @param array $p Parameter map with keys:
397 * - host : The hostname of the DB server
398 * - user : The name of the database user the client operates under
399 * - password : The password for the database user
400 * - dbname : The name of the database to use where queries do not specify one.
401 * The database must exist or an error might be thrown. Setting this to the empty string
402 * will avoid any such errors and make the handle have no implicit database scope. This is
403 * useful for queries like SHOW STATUS, CREATE DATABASE, or DROP DATABASE. Note that a
404 * "database" in Postgres is rougly equivalent to an entire MySQL server. This the domain
405 * in which user names and such are defined, e.g. users are database-specific in Postgres.
406 * - schema : The database schema to use (if supported). A "schema" in Postgres is roughly
407 * equivalent to a "database" in MySQL. Note that MySQL and SQLite do not use schemas.
408 * - tablePrefix : Optional table prefix that is implicitly added on to all table names
409 * recognized in queries. This can be used in place of schemas for handle site farms.
410 * - flags : Optional bitfield of DBO_* constants that define connection, protocol,
411 * buffering, and transaction behavior. It is STRONGLY adviced to leave the DBO_DEFAULT
412 * flag in place UNLESS this this database simply acts as a key/value store.
413 * - driver: Optional name of a specific DB client driver. For MySQL, there is only the
414 * 'mysqli' driver; the old one 'mysql' has been removed.
415 * - variables: Optional map of session variables to set after connecting. This can be
416 * used to adjust lock timeouts or encoding modes and the like.
417 * - connLogger: Optional PSR-3 logger interface instance.
418 * - queryLogger: Optional PSR-3 logger interface instance.
419 * - profiler : Optional callback that takes a section name argument and returns
420 * a ScopedCallback instance that ends the profile section in its destructor.
421 * These will be called in query(), using a simplified version of the SQL that
422 * also includes the agent as a SQL comment.
423 * - trxProfiler: Optional TransactionProfiler instance.
424 * - errorLogger: Optional callback that takes an Exception and logs it.
425 * - deprecationLogger: Optional callback that takes a string and logs it.
426 * - cliMode: Whether to consider the execution context that of a CLI script.
427 * - agent: Optional name used to identify the end-user in query profiling/logging.
428 * - srvCache: Optional BagOStuff instance to an APC-style cache.
429 * - nonNativeInsertSelectBatchSize: Optional batch size for non-native INSERT SELECT emulation.
430 * @param int $connect One of the class constants (NEW_CONNECTED, NEW_UNCONNECTED) [optional]
431 * @return Database|null If the database driver or extension cannot be found
432 * @throws InvalidArgumentException If the database driver or extension cannot be found
435 final public static function factory( $dbType, $p = [], $connect = self
::NEW_CONNECTED
) {
436 $class = self
::getClass( $dbType, $p['driver'] ??
null );
438 if ( class_exists( $class ) && is_subclass_of( $class, IDatabase
::class ) ) {
439 // Resolve some defaults for b/c
440 $p['host'] = $p['host'] ??
false;
441 $p['user'] = $p['user'] ??
false;
442 $p['password'] = $p['password'] ??
false;
443 $p['dbname'] = $p['dbname'] ??
false;
444 $p['flags'] = $p['flags'] ??
0;
445 $p['variables'] = $p['variables'] ??
[];
446 $p['tablePrefix'] = $p['tablePrefix'] ??
'';
447 $p['schema'] = $p['schema'] ??
null;
448 $p['cliMode'] = $p['cliMode'] ??
( PHP_SAPI
=== 'cli' || PHP_SAPI
=== 'phpdbg' );
449 $p['agent'] = $p['agent'] ??
'';
450 if ( !isset( $p['connLogger'] ) ) {
451 $p['connLogger'] = new NullLogger();
453 if ( !isset( $p['queryLogger'] ) ) {
454 $p['queryLogger'] = new NullLogger();
456 $p['profiler'] = $p['profiler'] ??
null;
457 if ( !isset( $p['trxProfiler'] ) ) {
458 $p['trxProfiler'] = new TransactionProfiler();
460 if ( !isset( $p['errorLogger'] ) ) {
461 $p['errorLogger'] = function ( Exception
$e ) {
462 trigger_error( get_class( $e ) . ': ' . $e->getMessage(), E_USER_WARNING
);
465 if ( !isset( $p['deprecationLogger'] ) ) {
466 $p['deprecationLogger'] = function ( $msg ) {
467 trigger_error( $msg, E_USER_DEPRECATED
);
471 /** @var Database $conn */
472 $conn = new $class( $p );
473 if ( $connect == self
::NEW_CONNECTED
) {
474 $conn->initConnection();
484 * @param string $dbType A possible DB type (sqlite, mysql, postgres,...)
485 * @param string|null $driver Optional name of a specific DB client driver
486 * @return array Map of (Database::ATTR_* constant => value) for all such constants
487 * @throws InvalidArgumentException
490 final public static function attributesFromType( $dbType, $driver = null ) {
492 self
::ATTR_DB_LEVEL_LOCKING
=> false,
493 self
::ATTR_SCHEMAS_AS_TABLE_GROUPS
=> false
496 $class = self
::getClass( $dbType, $driver );
498 return call_user_func( [ $class, 'getAttributes' ] ) +
$defaults;
502 * @param string $dbType A possible DB type (sqlite, mysql, postgres,...)
503 * @param string|null $driver Optional name of a specific DB client driver
504 * @return string Database subclass name to use
505 * @throws InvalidArgumentException
507 private static function getClass( $dbType, $driver = null ) {
508 // For database types with built-in support, the below maps type to IDatabase
509 // implementations. For types with multipe driver implementations (PHP extensions),
510 // an array can be used, keyed by extension name. In case of an array, the
511 // optional 'driver' parameter can be used to force a specific driver. Otherwise,
512 // we auto-detect the first available driver. For types without built-in support,
513 // an class named "Database<Type>" us used, eg. DatabaseFoo for type 'foo'.
514 static $builtinTypes = [
515 'mssql' => DatabaseMssql
::class,
516 'mysql' => [ 'mysqli' => DatabaseMysqli
::class ],
517 'sqlite' => DatabaseSqlite
::class,
518 'postgres' => DatabasePostgres
::class,
521 $dbType = strtolower( $dbType );
524 if ( isset( $builtinTypes[$dbType] ) ) {
525 $possibleDrivers = $builtinTypes[$dbType];
526 if ( is_string( $possibleDrivers ) ) {
527 $class = $possibleDrivers;
528 } elseif ( (string)$driver !== '' ) {
529 if ( !isset( $possibleDrivers[$driver] ) ) {
530 throw new InvalidArgumentException( __METHOD__
.
531 " type '$dbType' does not support driver '{$driver}'" );
534 $class = $possibleDrivers[$driver];
536 foreach ( $possibleDrivers as $posDriver => $possibleClass ) {
537 if ( extension_loaded( $posDriver ) ) {
538 $class = $possibleClass;
544 $class = 'Database' . ucfirst( $dbType );
547 if ( $class === false ) {
548 throw new InvalidArgumentException( __METHOD__
.
549 " no viable database extension found for type '$dbType'" );
556 * @return array Map of (Database::ATTR_* constant => value
559 protected static function getAttributes() {
564 * Set the PSR-3 logger interface to use for query logging. (The logger
565 * interfaces for connection logging and error logging can be set with the
568 * @param LoggerInterface $logger
570 public function setLogger( LoggerInterface
$logger ) {
571 $this->queryLogger
= $logger;
574 public function getServerInfo() {
575 return $this->getServerVersion();
578 public function bufferResults( $buffer = null ) {
579 $res = !$this->getFlag( self
::DBO_NOBUFFER
);
580 if ( $buffer !== null ) {
582 ?
$this->clearFlag( self
::DBO_NOBUFFER
)
583 : $this->setFlag( self
::DBO_NOBUFFER
);
589 public function trxLevel() {
590 return $this->trxLevel
;
593 public function trxTimestamp() {
594 return $this->trxLevel ?
$this->trxTimestamp
: null;
598 * @return int One of the STATUS_TRX_* class constants
601 public function trxStatus() {
602 return $this->trxStatus
;
605 public function tablePrefix( $prefix = null ) {
606 $old = $this->currentDomain
->getTablePrefix();
607 if ( $prefix !== null ) {
608 $this->currentDomain
= new DatabaseDomain(
609 $this->currentDomain
->getDatabase(),
610 $this->currentDomain
->getSchema(),
618 public function dbSchema( $schema = null ) {
619 if ( strlen( $schema ) && $this->getDBname() === null ) {
620 throw new DBUnexpectedError( $this, "Cannot set schema to '$schema'; no database set." );
623 $old = $this->currentDomain
->getSchema();
624 if ( $schema !== null ) {
625 $this->currentDomain
= new DatabaseDomain(
626 $this->currentDomain
->getDatabase(),
627 // DatabaseDomain uses null for unspecified schemas
628 strlen( $schema ) ?
$schema : null,
629 $this->currentDomain
->getTablePrefix()
637 * @return string Schema to use to qualify relations in queries
639 protected function relationSchemaQualifier() {
640 return $this->dbSchema();
643 public function getLBInfo( $name = null ) {
644 if ( is_null( $name ) ) {
645 return $this->lbInfo
;
648 if ( array_key_exists( $name, $this->lbInfo
) ) {
649 return $this->lbInfo
[$name];
655 public function setLBInfo( $name, $value = null ) {
656 if ( is_null( $value ) ) {
657 $this->lbInfo
= $name;
659 $this->lbInfo
[$name] = $value;
663 public function setLazyMasterHandle( IDatabase
$conn ) {
664 $this->lazyMasterHandle
= $conn;
668 * @return IDatabase|null
669 * @see setLazyMasterHandle()
672 protected function getLazyMasterHandle() {
673 return $this->lazyMasterHandle
;
676 public function implicitGroupby() {
680 public function implicitOrderby() {
684 public function lastQuery() {
685 return $this->lastQuery
;
688 public function doneWrites() {
689 return (bool)$this->lastWriteTime
;
692 public function lastDoneWrites() {
693 return $this->lastWriteTime ?
: false;
696 public function writesPending() {
697 return $this->trxLevel
&& $this->trxDoneWrites
;
700 public function writesOrCallbacksPending() {
701 return $this->trxLevel
&& (
702 $this->trxDoneWrites ||
703 $this->trxIdleCallbacks ||
704 $this->trxPreCommitCallbacks ||
705 $this->trxEndCallbacks
709 public function preCommitCallbacksPending() {
710 return $this->trxLevel
&& $this->trxPreCommitCallbacks
;
714 * @return string|null
716 final protected function getTransactionRoundId() {
717 // If transaction round participation is enabled, see if one is active
718 if ( $this->getFlag( self
::DBO_TRX
) ) {
719 $id = $this->getLBInfo( 'trxRoundId' );
721 return is_string( $id ) ?
$id : null;
727 public function pendingWriteQueryDuration( $type = self
::ESTIMATE_TOTAL
) {
728 if ( !$this->trxLevel
) {
730 } elseif ( !$this->trxDoneWrites
) {
735 case self
::ESTIMATE_DB_APPLY
:
736 return $this->pingAndCalculateLastTrxApplyTime();
737 default: // everything
738 return $this->trxWriteDuration
;
743 * @return float Time to apply writes to replicas based on trxWrite* fields
745 private function pingAndCalculateLastTrxApplyTime() {
748 $rttAdjTotal = $this->trxWriteAdjQueryCount
* $rtt;
749 $applyTime = max( $this->trxWriteAdjDuration
- $rttAdjTotal, 0 );
750 // For omitted queries, make them count as something at least
751 $omitted = $this->trxWriteQueryCount
- $this->trxWriteAdjQueryCount
;
752 $applyTime +
= self
::TINY_WRITE_SEC
* $omitted;
757 public function pendingWriteCallers() {
758 return $this->trxLevel ?
$this->trxWriteCallers
: [];
761 public function pendingWriteRowsAffected() {
762 return $this->trxWriteAffectedRows
;
766 * List the methods that have write queries or callbacks for the current transaction
768 * This method should not be used outside of Database/LoadBalancer
773 public function pendingWriteAndCallbackCallers() {
774 $fnames = $this->pendingWriteCallers();
776 $this->trxIdleCallbacks
,
777 $this->trxPreCommitCallbacks
,
778 $this->trxEndCallbacks
780 foreach ( $callbacks as $callback ) {
781 $fnames[] = $callback[1];
791 private function flatAtomicSectionList() {
792 return array_reduce( $this->trxAtomicLevels
, function ( $accum, $v ) {
793 return $accum === null ?
$v[0] : "$accum, " . $v[0];
797 public function isOpen() {
798 return $this->opened
;
801 public function setFlag( $flag, $remember = self
::REMEMBER_NOTHING
) {
802 if ( ( $flag & self
::DBO_IGNORE
) ) {
803 throw new UnexpectedValueException( "Modifying DBO_IGNORE is not allowed." );
806 if ( $remember === self
::REMEMBER_PRIOR
) {
807 array_push( $this->priorFlags
, $this->flags
);
809 $this->flags |
= $flag;
812 public function clearFlag( $flag, $remember = self
::REMEMBER_NOTHING
) {
813 if ( ( $flag & self
::DBO_IGNORE
) ) {
814 throw new UnexpectedValueException( "Modifying DBO_IGNORE is not allowed." );
817 if ( $remember === self
::REMEMBER_PRIOR
) {
818 array_push( $this->priorFlags
, $this->flags
);
820 $this->flags
&= ~
$flag;
823 public function restoreFlags( $state = self
::RESTORE_PRIOR
) {
824 if ( !$this->priorFlags
) {
828 if ( $state === self
::RESTORE_INITIAL
) {
829 $this->flags
= reset( $this->priorFlags
);
830 $this->priorFlags
= [];
832 $this->flags
= array_pop( $this->priorFlags
);
836 public function getFlag( $flag ) {
837 return (bool)( $this->flags
& $flag );
841 * @param string $name Class field name
843 * @deprecated Since 1.28
845 public function getProperty( $name ) {
849 public function getDomainID() {
850 return $this->currentDomain
->getId();
853 final public function getWikiID() {
854 return $this->getDomainID();
858 * Get information about an index into an object
859 * @param string $table Table name
860 * @param string $index Index name
861 * @param string $fname Calling function name
862 * @return mixed Database-specific index description class or false if the index does not exist
864 abstract function indexInfo( $table, $index, $fname = __METHOD__
);
867 * Wrapper for addslashes()
869 * @param string $s String to be slashed.
870 * @return string Slashed string.
872 abstract function strencode( $s );
875 * Set a custom error handler for logging errors during database connection
877 protected function installErrorHandler() {
878 $this->lastPhpError
= false;
879 $this->htmlErrors
= ini_set( 'html_errors', '0' );
880 set_error_handler( [ $this, 'connectionErrorLogger' ] );
884 * Restore the previous error handler and return the last PHP error for this DB
886 * @return bool|string
888 protected function restoreErrorHandler() {
889 restore_error_handler();
890 if ( $this->htmlErrors
!== false ) {
891 ini_set( 'html_errors', $this->htmlErrors
);
894 return $this->getLastPHPError();
898 * @return string|bool Last PHP error for this DB (typically connection errors)
900 protected function getLastPHPError() {
901 if ( $this->lastPhpError
) {
902 $error = preg_replace( '!\[<a.*</a>\]!', '', $this->lastPhpError
);
903 $error = preg_replace( '!^.*?:\s?(.*)$!', '$1', $error );
912 * Error handler for logging errors during database connection
913 * This method should not be used outside of Database classes
916 * @param string $errstr
918 public function connectionErrorLogger( $errno, $errstr ) {
919 $this->lastPhpError
= $errstr;
923 * Create a log context to pass to PSR-3 logger functions.
925 * @param array $extras Additional data to add to context
928 protected function getLogContext( array $extras = [] ) {
931 'db_server' => $this->server
,
932 'db_name' => $this->getDBname(),
933 'db_user' => $this->user
,
939 final public function close() {
940 $exception = null; // error to throw after disconnecting
942 $wasOpen = $this->opened
;
943 // This should mostly do nothing if the connection is already closed
945 // Roll back any dangling transaction first
946 if ( $this->trxLevel
) {
947 if ( $this->trxAtomicLevels
) {
948 // Cannot let incomplete atomic sections be committed
949 $levels = $this->flatAtomicSectionList();
950 $exception = new DBUnexpectedError(
952 __METHOD__
. ": atomic sections $levels are still open."
954 } elseif ( $this->trxAutomatic
) {
955 // Only the connection manager can commit non-empty DBO_TRX transactions
956 // (empty ones we can silently roll back)
957 if ( $this->writesOrCallbacksPending() ) {
958 $exception = new DBUnexpectedError(
961 ": mass commit/rollback of peer transaction required (DBO_TRX set)."
965 // Manual transactions should have been committed or rolled
966 // back, even if empty.
967 $exception = new DBUnexpectedError(
969 __METHOD__
. ": transaction is still open (from {$this->trxFname})."
973 if ( $this->trxEndCallbacksSuppressed
) {
974 $exception = $exception ?
: new DBUnexpectedError(
976 __METHOD__
. ': callbacks are suppressed; cannot properly commit.'
980 // Rollback the changes and run any callbacks as needed
981 $this->rollback( __METHOD__
, self
::FLUSHING_INTERNAL
);
984 // Close the actual connection in the binding handle
985 $closed = $this->closeConnection();
987 $closed = true; // already closed; nothing to do
991 $this->opened
= false;
993 // Throw any unexpected errors after having disconnected
994 if ( $exception instanceof Exception
) {
998 // Note that various subclasses call close() at the start of open(), which itself is
999 // called by replaceLostConnection(). In that case, just because onTransactionResolution()
1000 // callbacks are pending does not mean that an exception should be thrown. Rather, they
1001 // will be executed after the reconnection step.
1003 // Sanity check that no callbacks are dangling
1004 $fnames = $this->pendingWriteAndCallbackCallers();
1006 throw new RuntimeException(
1007 "Transaction callbacks are still pending:\n" . implode( ', ', $fnames )
1016 * Make sure there is an open connection handle (alive or not) as a sanity check
1018 * This guards against fatal errors to the binding handle not being defined
1019 * in cases where open() was never called or close() was already called
1021 * @throws DBUnexpectedError
1023 protected function assertHasConnectionHandle() {
1024 if ( !$this->isOpen() ) {
1025 throw new DBUnexpectedError( $this, "DB connection was already closed." );
1030 * Make sure that this server is not marked as a replica nor read-only as a sanity check
1032 * @throws DBUnexpectedError
1034 protected function assertIsWritableMaster() {
1035 if ( $this->getLBInfo( 'replica' ) === true ) {
1036 throw new DBReadOnlyRoleError(
1038 'Write operations are not allowed on replica database connections.'
1041 $reason = $this->getReadOnlyReason();
1042 if ( $reason !== false ) {
1043 throw new DBReadOnlyError( $this, "Database is read-only: $reason" );
1048 * Closes underlying database connection
1050 * @return bool Whether connection was closed successfully
1052 abstract protected function closeConnection();
1055 * @deprecated since 1.32
1056 * @param string $error Fallback message, if none is given by DB
1057 * @throws DBConnectionError
1059 public function reportConnectionError( $error = 'Unknown error' ) {
1060 call_user_func( $this->deprecationLogger
, 'Use of ' . __METHOD__
. ' is deprecated.' );
1061 throw new DBConnectionError( $this, $this->lastError() ?
: $error );
1065 * Run a query and return a DBMS-dependent wrapper or boolean
1067 * For SELECT queries, this returns either:
1068 * - a) A driver-specific value/resource, only on success. This can be iterated
1069 * over by calling fetchObject()/fetchRow() until there are no more rows.
1070 * Alternatively, the result can be passed to resultObject() to obtain a
1071 * ResultWrapper instance which can then be iterated over via "foreach".
1072 * - b) False, on any query failure
1074 * For non-SELECT queries, this returns either:
1075 * - a) A driver-specific value/resource, only on success
1076 * - b) True, only on success (e.g. no meaningful result other than "OK")
1077 * - c) False, on any query failure
1079 * @param string $sql SQL query
1080 * @return mixed|bool An object, resource, or true on success; false on failure
1082 abstract protected function doQuery( $sql );
1085 * Determine whether a query writes to the DB. When in doubt, this returns true.
1089 * - Subsequent web requests should not need to wait for replication from
1090 * the master position seen by this web request, unless this request made
1091 * changes to the master. This is handled by ChronologyProtector by checking
1092 * doneWrites() at the end of the request. doneWrites() returns true if any
1093 * query set lastWriteTime; which query() does based on isWriteQuery().
1095 * - Reject write queries to replica DBs, in query().
1097 * @param string $sql
1100 protected function isWriteQuery( $sql ) {
1101 // BEGIN and COMMIT queries are considered read queries here.
1102 // Database backends and drivers (MySQL, MariaDB, php-mysqli) generally
1103 // treat these as write queries, in that their results have "affected rows"
1104 // as meta data as from writes, instead of "num rows" as from reads.
1105 // But, we treat them as read queries because when reading data (from
1106 // either replica or master) we use transactions to enable repeatable-read
1107 // snapshots, which ensures we get consistent results from the same snapshot
1108 // for all queries within a request. Use cases:
1109 // - Treating these as writes would trigger ChronologyProtector (see method doc).
1110 // - We use this method to reject writes to replicas, but we need to allow
1111 // use of transactions on replicas for read snapshots. This fine given
1112 // that transactions by themselves don't make changes, only actual writes
1113 // within the transaction matter, which we still detect.
1115 '/^(?:SELECT|BEGIN|ROLLBACK|COMMIT|SAVEPOINT|RELEASE|SET|SHOW|EXPLAIN|\(SELECT)\b/i',
1121 * @param string $sql
1122 * @return string|null
1124 protected function getQueryVerb( $sql ) {
1125 return preg_match( '/^\s*([a-z]+)/i', $sql, $m ) ?
strtoupper( $m[1] ) : null;
1129 * Determine whether a SQL statement is sensitive to isolation level.
1131 * A SQL statement is considered transactable if its result could vary
1132 * depending on the transaction isolation level. Operational commands
1133 * such as 'SET' and 'SHOW' are not considered to be transactable.
1135 * Main purpose: Used by query() to decide whether to begin a transaction
1136 * before the current query (in DBO_TRX mode, on by default).
1138 * @param string $sql
1141 protected function isTransactableQuery( $sql ) {
1143 $this->getQueryVerb( $sql ),
1144 [ 'BEGIN', 'ROLLBACK', 'COMMIT', 'SET', 'SHOW', 'CREATE', 'ALTER' ],
1150 * @param string $sql A SQL query
1151 * @param bool $pseudoPermanent Treat any table from CREATE TEMPORARY as pseudo-permanent
1152 * @return int|null A self::TEMP_* constant for temp table operations or null otherwise
1154 protected function registerTempTableWrite( $sql, $pseudoPermanent ) {
1155 static $qt = '[`"\']?(\w+)[`"\']?'; // quoted table
1158 '/^CREATE\s+TEMPORARY\s+TABLE\s+(?:IF\s+NOT\s+EXISTS\s+)?' . $qt . '/i',
1162 $type = $pseudoPermanent ? self
::TEMP_PSEUDO_PERMANENT
: self
::TEMP_NORMAL
;
1163 $this->sessionTempTables
[$matches[1]] = $type;
1166 } elseif ( preg_match(
1167 '/^DROP\s+(?:TEMPORARY\s+)?TABLE\s+(?:IF\s+EXISTS\s+)?' . $qt . '/i',
1171 $type = $this->sessionTempTables
[$matches[1]] ??
null;
1172 unset( $this->sessionTempTables
[$matches[1]] );
1175 } elseif ( preg_match(
1176 '/^TRUNCATE\s+(?:TEMPORARY\s+)?TABLE\s+(?:IF\s+EXISTS\s+)?' . $qt . '/i',
1180 return $this->sessionTempTables
[$matches[1]] ??
null;
1181 } elseif ( preg_match(
1182 '/^(?:(?:INSERT|REPLACE)\s+(?:\w+\s+)?INTO|UPDATE|DELETE\s+FROM)\s+' . $qt . '/i',
1186 return $this->sessionTempTables
[$matches[1]] ??
null;
1192 public function query( $sql, $fname = __METHOD__
, $flags = 0 ) {
1193 $this->assertTransactionStatus( $sql, $fname );
1194 $this->assertHasConnectionHandle();
1196 $flags = (int)$flags; // b/c; this field used to be a bool
1197 $ignoreErrors = $this->hasFlags( $flags, self
::QUERY_SILENCE_ERRORS
);
1199 $priorTransaction = $this->trxLevel
;
1200 $priorWritesPending = $this->writesOrCallbacksPending();
1202 if ( $this->isWriteQuery( $sql ) ) {
1203 # In theory, non-persistent writes are allowed in read-only mode, but due to things
1204 # like https://bugs.mysql.com/bug.php?id=33669 that might not work anyway...
1205 $this->assertIsWritableMaster();
1206 # Do not treat temporary table writes as "meaningful writes" that need committing.
1207 # Profile them as reads. Integration tests can override this behavior via $flags.
1208 $pseudoPermanent = $this->hasFlags( $flags, self
::QUERY_PSEUDO_PERMANENT
);
1209 $tableType = $this->registerTempTableWrite( $sql, $pseudoPermanent );
1210 $isEffectiveWrite = ( $tableType !== self
::TEMP_NORMAL
);
1211 # DBConnRef uses QUERY_REPLICA_ROLE to enforce the replica role for raw SQL queries
1212 if ( $isEffectiveWrite && $this->hasFlags( $flags, self
::QUERY_REPLICA_ROLE
) ) {
1213 throw new DBReadOnlyRoleError( $this, "Cannot write; target role is DB_REPLICA" );
1216 $isEffectiveWrite = false;
1219 # Add trace comment to the begin of the sql string, right after the operator.
1220 # Or, for one-word queries (like "BEGIN" or COMMIT") add it to the end (T44598)
1221 $commentedSql = preg_replace( '/\s|$/', " /* $fname {$this->agent} */ ", $sql, 1 );
1223 # Send the query to the server and fetch any corresponding errors
1224 $ret = $this->attemptQuery( $sql, $commentedSql, $isEffectiveWrite, $fname );
1225 $lastError = $this->lastError();
1226 $lastErrno = $this->lastErrno();
1228 $recoverableSR = false; // recoverable statement rollback?
1229 $recoverableCL = false; // recoverable connection loss?
1231 if ( $ret === false && $this->wasConnectionLoss() ) {
1232 # Check if no meaningful session state was lost
1233 $recoverableCL = $this->canRecoverFromDisconnect( $sql, $priorWritesPending );
1234 # Update session state tracking and try to restore the connection
1235 $reconnected = $this->replaceLostConnection( __METHOD__
);
1236 # Silently resend the query to the server if it is safe and possible
1237 if ( $recoverableCL && $reconnected ) {
1238 $ret = $this->attemptQuery( $sql, $commentedSql, $isEffectiveWrite, $fname );
1239 $lastError = $this->lastError();
1240 $lastErrno = $this->lastErrno();
1242 if ( $ret === false && $this->wasConnectionLoss() ) {
1243 # Query probably causes disconnects; reconnect and do not re-run it
1244 $this->replaceLostConnection( __METHOD__
);
1246 $recoverableCL = false; // connection does not need recovering
1247 $recoverableSR = $this->wasKnownStatementRollbackError();
1251 $recoverableSR = $this->wasKnownStatementRollbackError();
1254 if ( $ret === false ) {
1255 if ( $priorTransaction ) {
1256 if ( $recoverableSR ) {
1257 # We're ignoring an error that caused just the current query to be aborted.
1258 # But log the cause so we can log a deprecation notice if a caller actually
1260 $this->trxStatusIgnoredCause
= [ $lastError, $lastErrno, $fname ];
1261 } elseif ( !$recoverableCL ) {
1262 # Either the query was aborted or all queries after BEGIN where aborted.
1263 # In the first case, the only options going forward are (a) ROLLBACK, or
1264 # (b) ROLLBACK TO SAVEPOINT (if one was set). If the later case, the only
1265 # option is ROLLBACK, since the snapshots would have been released.
1266 $this->trxStatus
= self
::STATUS_TRX_ERROR
;
1267 $this->trxStatusCause
=
1268 $this->getQueryExceptionAndLog( $lastError, $lastErrno, $sql, $fname );
1269 $ignoreErrors = false; // cannot recover
1270 $this->trxStatusIgnoredCause
= null;
1274 $this->reportQueryError( $lastError, $lastErrno, $sql, $fname, $ignoreErrors );
1277 return $this->resultObject( $ret );
1281 * Wrapper for query() that also handles profiling, logging, and affected row count updates
1283 * @param string $sql Original SQL query
1284 * @param string $commentedSql SQL query with debugging/trace comment
1285 * @param bool $isEffectiveWrite Whether the query is a (non-temporary table) write
1286 * @param string $fname Name of the calling function
1287 * @return bool|ResultWrapper True for a successful write query, ResultWrapper
1288 * object for a successful read query, or false on failure
1290 private function attemptQuery( $sql, $commentedSql, $isEffectiveWrite, $fname ) {
1291 $this->beginIfImplied( $sql, $fname );
1293 // Keep track of whether the transaction has write queries pending
1294 if ( $isEffectiveWrite ) {
1295 $this->lastWriteTime
= microtime( true );
1296 if ( $this->trxLevel
&& !$this->trxDoneWrites
) {
1297 $this->trxDoneWrites
= true;
1298 $this->trxProfiler
->transactionWritingIn(
1299 $this->server
, $this->getDomainID(), $this->trxShortId
);
1303 $prefix = !is_null( $this->getLBInfo( 'master' ) ) ?
'query-m: ' : 'query: ';
1304 $generalizedSql = new GeneralizedSql( $sql, $this->trxShortId
, $prefix );
1306 $startTime = microtime( true );
1307 $ps = $this->profiler
1308 ?
( $this->profiler
)( $generalizedSql->stringify() )
1310 $this->affectedRowCount
= null;
1311 $this->lastQuery
= $sql;
1312 $ret = $this->doQuery( $commentedSql );
1313 $this->affectedRowCount
= $this->affectedRows();
1314 unset( $ps ); // profile out (if set)
1315 $queryRuntime = max( microtime( true ) - $startTime, 0.0 );
1317 if ( $ret !== false ) {
1318 $this->lastPing
= $startTime;
1319 if ( $isEffectiveWrite && $this->trxLevel
) {
1320 $this->updateTrxWriteQueryTime( $sql, $queryRuntime, $this->affectedRows() );
1321 $this->trxWriteCallers
[] = $fname;
1325 if ( $sql === self
::PING_QUERY
) {
1326 $this->rttEstimate
= $queryRuntime;
1329 $this->trxProfiler
->recordQueryCompletion(
1333 $isEffectiveWrite ?
$this->affectedRows() : $this->numRows( $ret )
1336 // Avoid the overhead of logging calls unless debug mode is enabled
1337 if ( $this->getFlag( self
::DBO_DEBUG
) ) {
1338 $this->queryLogger
->debug(
1339 "{method} [{runtime}s]: $sql",
1342 'db_host' => $this->getServer(),
1343 'domain' => $this->getDomainID(),
1344 'runtime' => round( $queryRuntime, 3 )
1353 * Start an implicit transaction if DBO_TRX is enabled and no transaction is active
1355 * @param string $sql
1356 * @param string $fname
1358 private function beginIfImplied( $sql, $fname ) {
1361 $this->getFlag( self
::DBO_TRX
) &&
1362 $this->isTransactableQuery( $sql )
1364 $this->begin( __METHOD__
. " ($fname)", self
::TRANSACTION_INTERNAL
);
1365 $this->trxAutomatic
= true;
1370 * Update the estimated run-time of a query, not counting large row lock times
1372 * LoadBalancer can be set to rollback transactions that will create huge replication
1373 * lag. It bases this estimate off of pendingWriteQueryDuration(). Certain simple
1374 * queries, like inserting a row can take a long time due to row locking. This method
1375 * uses some simple heuristics to discount those cases.
1377 * @param string $sql A SQL write query
1378 * @param float $runtime Total runtime, including RTT
1379 * @param int $affected Affected row count
1381 private function updateTrxWriteQueryTime( $sql, $runtime, $affected ) {
1382 // Whether this is indicative of replica DB runtime (except for RBR or ws_repl)
1383 $indicativeOfReplicaRuntime = true;
1384 if ( $runtime > self
::SLOW_WRITE_SEC
) {
1385 $verb = $this->getQueryVerb( $sql );
1386 // insert(), upsert(), replace() are fast unless bulky in size or blocked on locks
1387 if ( $verb === 'INSERT' ) {
1388 $indicativeOfReplicaRuntime = $this->affectedRows() > self
::SMALL_WRITE_ROWS
;
1389 } elseif ( $verb === 'REPLACE' ) {
1390 $indicativeOfReplicaRuntime = $this->affectedRows() > self
::SMALL_WRITE_ROWS
/ 2;
1394 $this->trxWriteDuration +
= $runtime;
1395 $this->trxWriteQueryCount +
= 1;
1396 $this->trxWriteAffectedRows +
= $affected;
1397 if ( $indicativeOfReplicaRuntime ) {
1398 $this->trxWriteAdjDuration +
= $runtime;
1399 $this->trxWriteAdjQueryCount +
= 1;
1404 * Error out if the DB is not in a valid state for a query via query()
1406 * @param string $sql
1407 * @param string $fname
1408 * @throws DBTransactionStateError
1410 private function assertTransactionStatus( $sql, $fname ) {
1411 $verb = $this->getQueryVerb( $sql );
1412 if ( $verb === 'USE' ) {
1413 throw new DBUnexpectedError( $this, "Got USE query; use selectDomain() instead." );
1416 if ( $verb === 'ROLLBACK' ) { // transaction/savepoint
1420 if ( $this->trxStatus
< self
::STATUS_TRX_OK
) {
1421 throw new DBTransactionStateError(
1423 "Cannot execute query from $fname while transaction status is ERROR.",
1425 $this->trxStatusCause
1427 } elseif ( $this->trxStatus
=== self
::STATUS_TRX_OK
&& $this->trxStatusIgnoredCause
) {
1428 list( $iLastError, $iLastErrno, $iFname ) = $this->trxStatusIgnoredCause
;
1429 call_user_func( $this->deprecationLogger
,
1430 "Caller from $fname ignored an error originally raised from $iFname: " .
1431 "[$iLastErrno] $iLastError"
1433 $this->trxStatusIgnoredCause
= null;
1437 public function assertNoOpenTransactions() {
1438 if ( $this->explicitTrxActive() ) {
1439 throw new DBTransactionError(
1441 "Explicit transaction still active. A caller may have caught an error. "
1442 . "Open transactions: " . $this->flatAtomicSectionList()
1448 * Determine whether it is safe to retry queries after a database connection is lost
1450 * @param string $sql SQL query
1451 * @param bool $priorWritesPending Whether there is a transaction open with
1452 * possible write queries or transaction pre-commit/idle callbacks
1453 * waiting on it to finish.
1454 * @return bool True if it is safe to retry the query, false otherwise
1456 private function canRecoverFromDisconnect( $sql, $priorWritesPending ) {
1457 # Transaction dropped; this can mean lost writes, or REPEATABLE-READ snapshots.
1458 # Dropped connections also mean that named locks are automatically released.
1459 # Only allow error suppression in autocommit mode or when the lost transaction
1460 # didn't matter anyway (aside from DBO_TRX snapshot loss).
1461 if ( $this->namedLocksHeld
) {
1462 return false; // possible critical section violation
1463 } elseif ( $this->sessionTempTables
) {
1464 return false; // tables might be queried latter
1465 } elseif ( $sql === 'COMMIT' ) {
1466 return !$priorWritesPending; // nothing written anyway? (T127428)
1467 } elseif ( $sql === 'ROLLBACK' ) {
1468 return true; // transaction lost...which is also what was requested :)
1469 } elseif ( $this->explicitTrxActive() ) {
1470 return false; // don't drop atomocity and explicit snapshots
1471 } elseif ( $priorWritesPending ) {
1472 return false; // prior writes lost from implicit transaction
1479 * Clean things up after session (and thus transaction) loss before reconnect
1481 private function handleSessionLossPreconnect() {
1482 // Clean up tracking of session-level things...
1483 // https://dev.mysql.com/doc/refman/5.7/en/implicit-commit.html
1484 // https://www.postgresql.org/docs/9.2/static/sql-createtable.html (ignoring ON COMMIT)
1485 $this->sessionTempTables
= [];
1486 // https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_get-lock
1487 // https://www.postgresql.org/docs/9.4/static/functions-admin.html#FUNCTIONS-ADVISORY-LOCKS
1488 $this->namedLocksHeld
= [];
1489 // Session loss implies transaction loss
1490 $this->trxLevel
= 0;
1491 $this->trxAtomicCounter
= 0;
1492 $this->trxIdleCallbacks
= []; // T67263; transaction already lost
1493 $this->trxPreCommitCallbacks
= []; // T67263; transaction already lost
1494 // @note: leave trxRecurringCallbacks in place
1495 if ( $this->trxDoneWrites
) {
1496 $this->trxProfiler
->transactionWritingOut(
1498 $this->getDomainID(),
1500 $this->pendingWriteQueryDuration( self
::ESTIMATE_TOTAL
),
1501 $this->trxWriteAffectedRows
1507 * Clean things up after session (and thus transaction) loss after reconnect
1509 private function handleSessionLossPostconnect() {
1511 // Handle callbacks in trxEndCallbacks, e.g. onTransactionResolution().
1512 // If callback suppression is set then the array will remain unhandled.
1513 $this->runOnTransactionIdleCallbacks( self
::TRIGGER_ROLLBACK
);
1514 } catch ( Exception
$ex ) {
1515 // Already logged; move on...
1518 // Handle callbacks in trxRecurringCallbacks, e.g. setTransactionListener()
1519 $this->runTransactionListenerCallbacks( self
::TRIGGER_ROLLBACK
);
1520 } catch ( Exception
$ex ) {
1521 // Already logged; move on...
1526 * Checks whether the cause of the error is detected to be a timeout.
1528 * It returns false by default, and not all engines support detecting this yet.
1529 * If this returns false, it will be treated as a generic query error.
1531 * @param string $error Error text
1532 * @param int $errno Error number
1535 protected function wasQueryTimeout( $error, $errno ) {
1540 * Report a query error. Log the error, and if neither the object ignore
1541 * flag nor the $ignoreErrors flag is set, throw a DBQueryError.
1543 * @param string $error
1545 * @param string $sql
1546 * @param string $fname
1547 * @param bool $ignore
1548 * @throws DBQueryError
1550 public function reportQueryError( $error, $errno, $sql, $fname, $ignore = false ) {
1552 $this->queryLogger
->debug( "SQL ERROR (ignored): $error\n" );
1554 $exception = $this->getQueryExceptionAndLog( $error, $errno, $sql, $fname );
1561 * @param string $error
1562 * @param string|int $errno
1563 * @param string $sql
1564 * @param string $fname
1567 private function getQueryExceptionAndLog( $error, $errno, $sql, $fname ) {
1568 $sql1line = mb_substr( str_replace( "\n", "\\n", $sql ), 0, 5 * 1024 );
1569 $this->queryLogger
->error(
1570 "{fname}\t{db_server}\t{errno}\t{error}\t{sql1line}",
1571 $this->getLogContext( [
1572 'method' => __METHOD__
,
1575 'sql1line' => $sql1line,
1577 'trace' => ( new RuntimeException() )->getTraceAsString()
1580 $this->queryLogger
->debug( "SQL ERROR: " . $error . "\n" );
1581 if ( $this->wasQueryTimeout( $error, $errno ) ) {
1582 $e = new DBQueryTimeoutError( $this, $error, $errno, $sql, $fname );
1583 } elseif ( $this->wasConnectionError( $errno ) ) {
1584 $e = new DBQueryDisconnectedError( $this, $error, $errno, $sql, $fname );
1586 $e = new DBQueryError( $this, $error, $errno, $sql, $fname );
1592 public function freeResult( $res ) {
1595 public function selectField(
1596 $table, $var, $cond = '', $fname = __METHOD__
, $options = [], $join_conds = []
1598 if ( $var === '*' ) { // sanity
1599 throw new DBUnexpectedError( $this, "Cannot use a * field: got '$var'" );
1602 if ( !is_array( $options ) ) {
1603 $options = [ $options ];
1606 $options['LIMIT'] = 1;
1608 $res = $this->select( $table, $var, $cond, $fname, $options, $join_conds );
1609 if ( $res === false ||
!$this->numRows( $res ) ) {
1613 $row = $this->fetchRow( $res );
1615 if ( $row !== false ) {
1616 return reset( $row );
1622 public function selectFieldValues(
1623 $table, $var, $cond = '', $fname = __METHOD__
, $options = [], $join_conds = []
1625 if ( $var === '*' ) { // sanity
1626 throw new DBUnexpectedError( $this, "Cannot use a * field" );
1627 } elseif ( !is_string( $var ) ) { // sanity
1628 throw new DBUnexpectedError( $this, "Cannot use an array of fields" );
1631 if ( !is_array( $options ) ) {
1632 $options = [ $options ];
1635 $res = $this->select( $table, [ 'value' => $var ], $cond, $fname, $options, $join_conds );
1636 if ( $res === false ) {
1641 foreach ( $res as $row ) {
1642 $values[] = $row->value
;
1649 * Returns an optional USE INDEX clause to go after the table, and a
1650 * string to go at the end of the query.
1652 * @param array $options Associative array of options to be turned into
1653 * an SQL query, valid keys are listed in the function.
1655 * @see Database::select()
1657 protected function makeSelectOptions( $options ) {
1658 $preLimitTail = $postLimitTail = '';
1663 foreach ( $options as $key => $option ) {
1664 if ( is_numeric( $key ) ) {
1665 $noKeyOptions[$option] = true;
1669 $preLimitTail .= $this->makeGroupByWithHaving( $options );
1671 $preLimitTail .= $this->makeOrderBy( $options );
1673 if ( isset( $noKeyOptions['FOR UPDATE'] ) ) {
1674 $postLimitTail .= ' FOR UPDATE';
1677 if ( isset( $noKeyOptions['LOCK IN SHARE MODE'] ) ) {
1678 $postLimitTail .= ' LOCK IN SHARE MODE';
1681 if ( isset( $noKeyOptions['DISTINCT'] ) ||
isset( $noKeyOptions['DISTINCTROW'] ) ) {
1682 $startOpts .= 'DISTINCT';
1685 # Various MySQL extensions
1686 if ( isset( $noKeyOptions['STRAIGHT_JOIN'] ) ) {
1687 $startOpts .= ' /*! STRAIGHT_JOIN */';
1690 if ( isset( $noKeyOptions['HIGH_PRIORITY'] ) ) {
1691 $startOpts .= ' HIGH_PRIORITY';
1694 if ( isset( $noKeyOptions['SQL_BIG_RESULT'] ) ) {
1695 $startOpts .= ' SQL_BIG_RESULT';
1698 if ( isset( $noKeyOptions['SQL_BUFFER_RESULT'] ) ) {
1699 $startOpts .= ' SQL_BUFFER_RESULT';
1702 if ( isset( $noKeyOptions['SQL_SMALL_RESULT'] ) ) {
1703 $startOpts .= ' SQL_SMALL_RESULT';
1706 if ( isset( $noKeyOptions['SQL_CALC_FOUND_ROWS'] ) ) {
1707 $startOpts .= ' SQL_CALC_FOUND_ROWS';
1710 if ( isset( $noKeyOptions['SQL_CACHE'] ) ) {
1711 $startOpts .= ' SQL_CACHE';
1714 if ( isset( $noKeyOptions['SQL_NO_CACHE'] ) ) {
1715 $startOpts .= ' SQL_NO_CACHE';
1718 if ( isset( $options['USE INDEX'] ) && is_string( $options['USE INDEX'] ) ) {
1719 $useIndex = $this->useIndexClause( $options['USE INDEX'] );
1723 if ( isset( $options['IGNORE INDEX'] ) && is_string( $options['IGNORE INDEX'] ) ) {
1724 $ignoreIndex = $this->ignoreIndexClause( $options['IGNORE INDEX'] );
1729 return [ $startOpts, $useIndex, $preLimitTail, $postLimitTail, $ignoreIndex ];
1733 * Returns an optional GROUP BY with an optional HAVING
1735 * @param array $options Associative array of options
1737 * @see Database::select()
1740 protected function makeGroupByWithHaving( $options ) {
1742 if ( isset( $options['GROUP BY'] ) ) {
1743 $gb = is_array( $options['GROUP BY'] )
1744 ?
implode( ',', $options['GROUP BY'] )
1745 : $options['GROUP BY'];
1746 $sql .= ' GROUP BY ' . $gb;
1748 if ( isset( $options['HAVING'] ) ) {
1749 $having = is_array( $options['HAVING'] )
1750 ?
$this->makeList( $options['HAVING'], self
::LIST_AND
)
1751 : $options['HAVING'];
1752 $sql .= ' HAVING ' . $having;
1759 * Returns an optional ORDER BY
1761 * @param array $options Associative array of options
1763 * @see Database::select()
1766 protected function makeOrderBy( $options ) {
1767 if ( isset( $options['ORDER BY'] ) ) {
1768 $ob = is_array( $options['ORDER BY'] )
1769 ?
implode( ',', $options['ORDER BY'] )
1770 : $options['ORDER BY'];
1772 return ' ORDER BY ' . $ob;
1778 public function select(
1779 $table, $vars, $conds = '', $fname = __METHOD__
, $options = [], $join_conds = []
1781 $sql = $this->selectSQLText( $table, $vars, $conds, $fname, $options, $join_conds );
1783 return $this->query( $sql, $fname );
1786 public function selectSQLText( $table, $vars, $conds = '', $fname = __METHOD__
,
1787 $options = [], $join_conds = []
1789 if ( is_array( $vars ) ) {
1790 $fields = implode( ',', $this->fieldNamesWithAlias( $vars ) );
1795 $options = (array)$options;
1796 $useIndexes = ( isset( $options['USE INDEX'] ) && is_array( $options['USE INDEX'] ) )
1797 ?
$options['USE INDEX']
1800 isset( $options['IGNORE INDEX'] ) &&
1801 is_array( $options['IGNORE INDEX'] )
1803 ?
$options['IGNORE INDEX']
1807 $this->selectOptionsIncludeLocking( $options ) &&
1808 $this->selectFieldsOrOptionsAggregate( $vars, $options )
1810 // Some DB types (postgres/oracle) disallow FOR UPDATE with aggregate
1811 // functions. Discourage use of such queries to encourage compatibility.
1813 $this->deprecationLogger
,
1814 __METHOD__
. ": aggregation used with a locking SELECT ($fname)."
1818 if ( is_array( $table ) ) {
1820 $this->tableNamesWithIndexClauseOrJOIN(
1821 $table, $useIndexes, $ignoreIndexes, $join_conds );
1822 } elseif ( $table != '' ) {
1824 $this->tableNamesWithIndexClauseOrJOIN(
1825 [ $table ], $useIndexes, $ignoreIndexes, [] );
1830 list( $startOpts, $useIndex, $preLimitTail, $postLimitTail, $ignoreIndex ) =
1831 $this->makeSelectOptions( $options );
1833 if ( is_array( $conds ) ) {
1834 $conds = $this->makeList( $conds, self
::LIST_AND
);
1837 if ( $conds === null ||
$conds === false ) {
1838 $this->queryLogger
->warning(
1842 . ' with incorrect parameters: $conds must be a string or an array'
1847 if ( $conds === '' ||
$conds === '*' ) {
1848 $sql = "SELECT $startOpts $fields $from $useIndex $ignoreIndex $preLimitTail";
1849 } elseif ( is_string( $conds ) ) {
1850 $sql = "SELECT $startOpts $fields $from $useIndex $ignoreIndex " .
1851 "WHERE $conds $preLimitTail";
1853 throw new DBUnexpectedError( $this, __METHOD__
. ' called with incorrect parameters' );
1856 if ( isset( $options['LIMIT'] ) ) {
1857 $sql = $this->limitResult( $sql, $options['LIMIT'],
1858 $options['OFFSET'] ??
false );
1860 $sql = "$sql $postLimitTail";
1862 if ( isset( $options['EXPLAIN'] ) ) {
1863 $sql = 'EXPLAIN ' . $sql;
1869 public function selectRow( $table, $vars, $conds, $fname = __METHOD__
,
1870 $options = [], $join_conds = []
1872 $options = (array)$options;
1873 $options['LIMIT'] = 1;
1874 $res = $this->select( $table, $vars, $conds, $fname, $options, $join_conds );
1876 if ( $res === false ) {
1880 if ( !$this->numRows( $res ) ) {
1884 $obj = $this->fetchObject( $res );
1889 public function estimateRowCount(
1890 $table, $var = '*', $conds = '', $fname = __METHOD__
, $options = [], $join_conds = []
1892 $conds = $this->normalizeConditions( $conds, $fname );
1893 $column = $this->extractSingleFieldFromList( $var );
1894 if ( is_string( $column ) && !in_array( $column, [ '*', '1' ] ) ) {
1895 $conds[] = "$column IS NOT NULL";
1898 $res = $this->select(
1899 $table, [ 'rowcount' => 'COUNT(*)' ], $conds, $fname, $options, $join_conds
1901 $row = $res ?
$this->fetchRow( $res ) : [];
1903 return isset( $row['rowcount'] ) ?
(int)$row['rowcount'] : 0;
1906 public function selectRowCount(
1907 $tables, $var = '*', $conds = '', $fname = __METHOD__
, $options = [], $join_conds = []
1909 $conds = $this->normalizeConditions( $conds, $fname );
1910 $column = $this->extractSingleFieldFromList( $var );
1911 if ( is_string( $column ) && !in_array( $column, [ '*', '1' ] ) ) {
1912 $conds[] = "$column IS NOT NULL";
1915 $res = $this->select(
1917 'tmp_count' => $this->buildSelectSubquery(
1926 [ 'rowcount' => 'COUNT(*)' ],
1930 $row = $res ?
$this->fetchRow( $res ) : [];
1932 return isset( $row['rowcount'] ) ?
(int)$row['rowcount'] : 0;
1936 * @param string|array $options
1939 private function selectOptionsIncludeLocking( $options ) {
1940 $options = (array)$options;
1941 foreach ( [ 'FOR UPDATE', 'LOCK IN SHARE MODE' ] as $lock ) {
1942 if ( in_array( $lock, $options, true ) ) {
1951 * @param array|string $fields
1952 * @param array|string $options
1955 private function selectFieldsOrOptionsAggregate( $fields, $options ) {
1956 foreach ( (array)$options as $key => $value ) {
1957 if ( is_string( $key ) ) {
1958 if ( preg_match( '/^(?:GROUP BY|HAVING)$/i', $key ) ) {
1961 } elseif ( is_string( $value ) ) {
1962 if ( preg_match( '/^(?:DISTINCT|DISTINCTROW)$/i', $value ) ) {
1968 $regex = '/^(?:COUNT|MIN|MAX|SUM|GROUP_CONCAT|LISTAGG|ARRAY_AGG)\s*\\(/i';
1969 foreach ( (array)$fields as $field ) {
1970 if ( is_string( $field ) && preg_match( $regex, $field ) ) {
1979 * @param array|string $conds
1980 * @param string $fname
1983 final protected function normalizeConditions( $conds, $fname ) {
1984 if ( $conds === null ||
$conds === false ) {
1985 $this->queryLogger
->warning(
1989 . ' with incorrect parameters: $conds must be a string or an array'
1994 if ( !is_array( $conds ) ) {
1995 $conds = ( $conds === '' ) ?
[] : [ $conds ];
2002 * @param array|string $var Field parameter in the style of select()
2003 * @return string|null Column name or null; ignores aliases
2004 * @throws DBUnexpectedError Errors out if multiple columns are given
2006 final protected function extractSingleFieldFromList( $var ) {
2007 if ( is_array( $var ) ) {
2010 } elseif ( count( $var ) == 1 ) {
2011 $column = $var[0] ??
reset( $var );
2013 throw new DBUnexpectedError( $this, __METHOD__
. ': got multiple columns.' );
2022 public function lockForUpdate(
2023 $table, $conds = '', $fname = __METHOD__
, $options = [], $join_conds = []
2025 if ( !$this->trxLevel
&& !$this->getFlag( self
::DBO_TRX
) ) {
2026 throw new DBUnexpectedError(
2028 __METHOD__
. ': no transaction is active nor is DBO_TRX set'
2032 $options = (array)$options;
2033 $options[] = 'FOR UPDATE';
2035 return $this->selectRowCount( $table, '*', $conds, $fname, $options, $join_conds );
2038 public function fieldExists( $table, $field, $fname = __METHOD__
) {
2039 $info = $this->fieldInfo( $table, $field );
2044 public function indexExists( $table, $index, $fname = __METHOD__
) {
2045 if ( !$this->tableExists( $table ) ) {
2049 $info = $this->indexInfo( $table, $index, $fname );
2050 if ( is_null( $info ) ) {
2053 return $info !== false;
2057 abstract public function tableExists( $table, $fname = __METHOD__
);
2059 public function indexUnique( $table, $index ) {
2060 $indexInfo = $this->indexInfo( $table, $index );
2062 if ( !$indexInfo ) {
2066 return !$indexInfo[0]->Non_unique
;
2070 * Helper for Database::insert().
2072 * @param array $options
2075 protected function makeInsertOptions( $options ) {
2076 return implode( ' ', $options );
2079 public function insert( $table, $a, $fname = __METHOD__
, $options = [] ) {
2080 # No rows to insert, easy just return now
2081 if ( !count( $a ) ) {
2085 $table = $this->tableName( $table );
2087 if ( !is_array( $options ) ) {
2088 $options = [ $options ];
2091 $options = $this->makeInsertOptions( $options );
2093 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
2095 $keys = array_keys( $a[0] );
2098 $keys = array_keys( $a );
2101 $sql = 'INSERT ' . $options .
2102 " INTO $table (" . implode( ',', $keys ) . ') VALUES ';
2106 foreach ( $a as $row ) {
2112 $sql .= '(' . $this->makeList( $row ) . ')';
2115 $sql .= '(' . $this->makeList( $a ) . ')';
2118 $this->query( $sql, $fname );
2124 * Make UPDATE options array for Database::makeUpdateOptions
2126 * @param array $options
2129 protected function makeUpdateOptionsArray( $options ) {
2130 if ( !is_array( $options ) ) {
2131 $options = [ $options ];
2136 if ( in_array( 'IGNORE', $options ) ) {
2144 * Make UPDATE options for the Database::update function
2146 * @param array $options The options passed to Database::update
2149 protected function makeUpdateOptions( $options ) {
2150 $opts = $this->makeUpdateOptionsArray( $options );
2152 return implode( ' ', $opts );
2155 public function update( $table, $values, $conds, $fname = __METHOD__
, $options = [] ) {
2156 $table = $this->tableName( $table );
2157 $opts = $this->makeUpdateOptions( $options );
2158 $sql = "UPDATE $opts $table SET " . $this->makeList( $values, self
::LIST_SET
);
2160 if ( $conds !== [] && $conds !== '*' ) {
2161 $sql .= " WHERE " . $this->makeList( $conds, self
::LIST_AND
);
2164 $this->query( $sql, $fname );
2169 public function makeList( $a, $mode = self
::LIST_COMMA
) {
2170 if ( !is_array( $a ) ) {
2171 throw new DBUnexpectedError( $this, __METHOD__
. ' called with incorrect parameters' );
2177 foreach ( $a as $field => $value ) {
2179 if ( $mode == self
::LIST_AND
) {
2181 } elseif ( $mode == self
::LIST_OR
) {
2190 if ( ( $mode == self
::LIST_AND ||
$mode == self
::LIST_OR
) && is_numeric( $field ) ) {
2191 $list .= "($value)";
2192 } elseif ( $mode == self
::LIST_SET
&& is_numeric( $field ) ) {
2195 ( $mode == self
::LIST_AND ||
$mode == self
::LIST_OR
) && is_array( $value )
2197 // Remove null from array to be handled separately if found
2198 $includeNull = false;
2199 foreach ( array_keys( $value, null, true ) as $nullKey ) {
2200 $includeNull = true;
2201 unset( $value[$nullKey] );
2203 if ( count( $value ) == 0 && !$includeNull ) {
2204 throw new InvalidArgumentException(
2205 __METHOD__
. ": empty input for field $field" );
2206 } elseif ( count( $value ) == 0 ) {
2207 // only check if $field is null
2208 $list .= "$field IS NULL";
2210 // IN clause contains at least one valid element
2211 if ( $includeNull ) {
2212 // Group subconditions to ensure correct precedence
2215 if ( count( $value ) == 1 ) {
2216 // Special-case single values, as IN isn't terribly efficient
2217 // Don't necessarily assume the single key is 0; we don't
2218 // enforce linear numeric ordering on other arrays here.
2219 $value = array_values( $value )[0];
2220 $list .= $field . " = " . $this->addQuotes( $value );
2222 $list .= $field . " IN (" . $this->makeList( $value ) . ") ";
2224 // if null present in array, append IS NULL
2225 if ( $includeNull ) {
2226 $list .= " OR $field IS NULL)";
2229 } elseif ( $value === null ) {
2230 if ( $mode == self
::LIST_AND ||
$mode == self
::LIST_OR
) {
2231 $list .= "$field IS ";
2232 } elseif ( $mode == self
::LIST_SET
) {
2233 $list .= "$field = ";
2238 $mode == self
::LIST_AND ||
$mode == self
::LIST_OR ||
$mode == self
::LIST_SET
2240 $list .= "$field = ";
2242 $list .= $mode == self
::LIST_NAMES ?
$value : $this->addQuotes( $value );
2249 public function makeWhereFrom2d( $data, $baseKey, $subKey ) {
2252 foreach ( $data as $base => $sub ) {
2253 if ( count( $sub ) ) {
2254 $conds[] = $this->makeList(
2255 [ $baseKey => $base, $subKey => array_keys( $sub ) ],
2261 return $this->makeList( $conds, self
::LIST_OR
);
2263 // Nothing to search for...
2268 public function aggregateValue( $valuedata, $valuename = 'value' ) {
2272 public function bitNot( $field ) {
2276 public function bitAnd( $fieldLeft, $fieldRight ) {
2277 return "($fieldLeft & $fieldRight)";
2280 public function bitOr( $fieldLeft, $fieldRight ) {
2281 return "($fieldLeft | $fieldRight)";
2284 public function buildConcat( $stringList ) {
2285 return 'CONCAT(' . implode( ',', $stringList ) . ')';
2288 public function buildGroupConcatField(
2289 $delim, $table, $field, $conds = '', $join_conds = []
2291 $fld = "GROUP_CONCAT($field SEPARATOR " . $this->addQuotes( $delim ) . ')';
2293 return '(' . $this->selectSQLText( $table, $fld, $conds, null, [], $join_conds ) . ')';
2296 public function buildSubstring( $input, $startPosition, $length = null ) {
2297 $this->assertBuildSubstringParams( $startPosition, $length );
2298 $functionBody = "$input FROM $startPosition";
2299 if ( $length !== null ) {
2300 $functionBody .= " FOR $length";
2302 return 'SUBSTRING(' . $functionBody . ')';
2306 * Check type and bounds for parameters to self::buildSubstring()
2308 * All supported databases have substring functions that behave the same for
2309 * positive $startPosition and non-negative $length, but behaviors differ when
2310 * given 0 or negative $startPosition or negative $length. The simplest
2311 * solution to that is to just forbid those values.
2313 * @param int $startPosition
2314 * @param int|null $length
2317 protected function assertBuildSubstringParams( $startPosition, $length ) {
2318 if ( !is_int( $startPosition ) ||
$startPosition <= 0 ) {
2319 throw new InvalidArgumentException(
2320 '$startPosition must be a positive integer'
2323 if ( !( is_int( $length ) && $length >= 0 ||
$length === null ) ) {
2324 throw new InvalidArgumentException(
2325 '$length must be null or an integer greater than or equal to 0'
2330 public function buildStringCast( $field ) {
2331 // In theory this should work for any standards-compliant
2332 // SQL implementation, although it may not be the best way to do it.
2333 return "CAST( $field AS CHARACTER )";
2336 public function buildIntegerCast( $field ) {
2337 return 'CAST( ' . $field . ' AS INTEGER )';
2340 public function buildSelectSubquery(
2341 $table, $vars, $conds = '', $fname = __METHOD__
,
2342 $options = [], $join_conds = []
2344 return new Subquery(
2345 $this->selectSQLText( $table, $vars, $conds, $fname, $options, $join_conds )
2349 public function databasesAreIndependent() {
2353 final public function selectDB( $db ) {
2354 $this->selectDomain( new DatabaseDomain(
2356 $this->currentDomain
->getSchema(),
2357 $this->currentDomain
->getTablePrefix()
2363 final public function selectDomain( $domain ) {
2364 $this->doSelectDomain( DatabaseDomain
::newFromId( $domain ) );
2367 protected function doSelectDomain( DatabaseDomain
$domain ) {
2368 $this->currentDomain
= $domain;
2371 public function getDBname() {
2372 return $this->currentDomain
->getDatabase();
2375 public function getServer() {
2376 return $this->server
;
2379 public function tableName( $name, $format = 'quoted' ) {
2380 if ( $name instanceof Subquery
) {
2381 throw new DBUnexpectedError(
2383 __METHOD__
. ': got Subquery instance when expecting a string.'
2387 # Skip the entire process when we have a string quoted on both ends.
2388 # Note that we check the end so that we will still quote any use of
2389 # use of `database`.table. But won't break things if someone wants
2390 # to query a database table with a dot in the name.
2391 if ( $this->isQuotedIdentifier( $name ) ) {
2395 # Lets test for any bits of text that should never show up in a table
2396 # name. Basically anything like JOIN or ON which are actually part of
2397 # SQL queries, but may end up inside of the table value to combine
2398 # sql. Such as how the API is doing.
2399 # Note that we use a whitespace test rather than a \b test to avoid
2400 # any remote case where a word like on may be inside of a table name
2401 # surrounded by symbols which may be considered word breaks.
2402 if ( preg_match( '/(^|\s)(DISTINCT|JOIN|ON|AS)(\s|$)/i', $name ) !== 0 ) {
2403 $this->queryLogger
->warning(
2404 __METHOD__
. ": use of subqueries is not supported this way.",
2405 [ 'trace' => ( new RuntimeException() )->getTraceAsString() ]
2411 # Split database and table into proper variables.
2412 list( $database, $schema, $prefix, $table ) = $this->qualifiedTableComponents( $name );
2414 # Quote $table and apply the prefix if not quoted.
2415 # $tableName might be empty if this is called from Database::replaceVars()
2416 $tableName = "{$prefix}{$table}";
2417 if ( $format === 'quoted'
2418 && !$this->isQuotedIdentifier( $tableName )
2419 && $tableName !== ''
2421 $tableName = $this->addIdentifierQuotes( $tableName );
2424 # Quote $schema and $database and merge them with the table name if needed
2425 $tableName = $this->prependDatabaseOrSchema( $schema, $tableName, $format );
2426 $tableName = $this->prependDatabaseOrSchema( $database, $tableName, $format );
2432 * Get the table components needed for a query given the currently selected database
2434 * @param string $name Table name in the form of db.schema.table, db.table, or table
2435 * @return array (DB name or "" for default, schema name, table prefix, table name)
2437 protected function qualifiedTableComponents( $name ) {
2438 # We reverse the explode so that database.table and table both output the correct table.
2439 $dbDetails = explode( '.', $name, 3 );
2440 if ( count( $dbDetails ) == 3 ) {
2441 list( $database, $schema, $table ) = $dbDetails;
2442 # We don't want any prefix added in this case
2444 } elseif ( count( $dbDetails ) == 2 ) {
2445 list( $database, $table ) = $dbDetails;
2446 # We don't want any prefix added in this case
2448 # In dbs that support it, $database may actually be the schema
2449 # but that doesn't affect any of the functionality here
2452 list( $table ) = $dbDetails;
2453 if ( isset( $this->tableAliases
[$table] ) ) {
2454 $database = $this->tableAliases
[$table]['dbname'];
2455 $schema = is_string( $this->tableAliases
[$table]['schema'] )
2456 ?
$this->tableAliases
[$table]['schema']
2457 : $this->relationSchemaQualifier();
2458 $prefix = is_string( $this->tableAliases
[$table]['prefix'] )
2459 ?
$this->tableAliases
[$table]['prefix']
2460 : $this->tablePrefix();
2463 $schema = $this->relationSchemaQualifier(); # Default schema
2464 $prefix = $this->tablePrefix(); # Default prefix
2468 return [ $database, $schema, $prefix, $table ];
2472 * @param string|null $namespace Database or schema
2473 * @param string $relation Name of table, view, sequence, etc...
2474 * @param string $format One of (raw, quoted)
2475 * @return string Relation name with quoted and merged $namespace as needed
2477 private function prependDatabaseOrSchema( $namespace, $relation, $format ) {
2478 if ( strlen( $namespace ) ) {
2479 if ( $format === 'quoted' && !$this->isQuotedIdentifier( $namespace ) ) {
2480 $namespace = $this->addIdentifierQuotes( $namespace );
2482 $relation = $namespace . '.' . $relation;
2488 public function tableNames() {
2489 $inArray = func_get_args();
2492 foreach ( $inArray as $name ) {
2493 $retVal[$name] = $this->tableName( $name );
2499 public function tableNamesN() {
2500 $inArray = func_get_args();
2503 foreach ( $inArray as $name ) {
2504 $retVal[] = $this->tableName( $name );
2511 * Get an aliased table name
2513 * This returns strings like "tableName AS newTableName" for aliased tables
2514 * and "(SELECT * from tableA) newTablename" for subqueries (e.g. derived tables)
2516 * @see Database::tableName()
2517 * @param string|Subquery $table Table name or object with a 'sql' field
2518 * @param string|bool $alias Table alias (optional)
2519 * @return string SQL name for aliased table. Will not alias a table to its own name
2521 protected function tableNameWithAlias( $table, $alias = false ) {
2522 if ( is_string( $table ) ) {
2523 $quotedTable = $this->tableName( $table );
2524 } elseif ( $table instanceof Subquery
) {
2525 $quotedTable = (string)$table;
2527 throw new InvalidArgumentException( "Table must be a string or Subquery." );
2530 if ( $alias === false ||
$alias === $table ) {
2531 if ( $table instanceof Subquery
) {
2532 throw new InvalidArgumentException( "Subquery table missing alias." );
2535 return $quotedTable;
2537 return $quotedTable . ' ' . $this->addIdentifierQuotes( $alias );
2542 * Gets an array of aliased table names
2544 * @param array $tables [ [alias] => table ]
2545 * @return string[] See tableNameWithAlias()
2547 protected function tableNamesWithAlias( $tables ) {
2549 foreach ( $tables as $alias => $table ) {
2550 if ( is_numeric( $alias ) ) {
2553 $retval[] = $this->tableNameWithAlias( $table, $alias );
2560 * Get an aliased field name
2561 * e.g. fieldName AS newFieldName
2563 * @param string $name Field name
2564 * @param string|bool $alias Alias (optional)
2565 * @return string SQL name for aliased field. Will not alias a field to its own name
2567 protected function fieldNameWithAlias( $name, $alias = false ) {
2568 if ( !$alias ||
(string)$alias === (string)$name ) {
2571 return $name . ' AS ' . $this->addIdentifierQuotes( $alias ); // PostgreSQL needs AS
2576 * Gets an array of aliased field names
2578 * @param array $fields [ [alias] => field ]
2579 * @return string[] See fieldNameWithAlias()
2581 protected function fieldNamesWithAlias( $fields ) {
2583 foreach ( $fields as $alias => $field ) {
2584 if ( is_numeric( $alias ) ) {
2587 $retval[] = $this->fieldNameWithAlias( $field, $alias );
2594 * Get the aliased table name clause for a FROM clause
2595 * which might have a JOIN and/or USE INDEX or IGNORE INDEX clause
2597 * @param array $tables ( [alias] => table )
2598 * @param array $use_index Same as for select()
2599 * @param array $ignore_index Same as for select()
2600 * @param array $join_conds Same as for select()
2603 protected function tableNamesWithIndexClauseOrJOIN(
2604 $tables, $use_index = [], $ignore_index = [], $join_conds = []
2608 $use_index = (array)$use_index;
2609 $ignore_index = (array)$ignore_index;
2610 $join_conds = (array)$join_conds;
2612 foreach ( $tables as $alias => $table ) {
2613 if ( !is_string( $alias ) ) {
2614 // No alias? Set it equal to the table name
2618 if ( is_array( $table ) ) {
2619 // A parenthesized group
2620 if ( count( $table ) > 1 ) {
2621 $joinedTable = '(' .
2622 $this->tableNamesWithIndexClauseOrJOIN(
2623 $table, $use_index, $ignore_index, $join_conds ) . ')';
2626 $innerTable = reset( $table );
2627 $innerAlias = key( $table );
2628 $joinedTable = $this->tableNameWithAlias(
2630 is_string( $innerAlias ) ?
$innerAlias : $innerTable
2634 $joinedTable = $this->tableNameWithAlias( $table, $alias );
2637 // Is there a JOIN clause for this table?
2638 if ( isset( $join_conds[$alias] ) ) {
2639 list( $joinType, $conds ) = $join_conds[$alias];
2640 $tableClause = $joinType;
2641 $tableClause .= ' ' . $joinedTable;
2642 if ( isset( $use_index[$alias] ) ) { // has USE INDEX?
2643 $use = $this->useIndexClause( implode( ',', (array)$use_index[$alias] ) );
2645 $tableClause .= ' ' . $use;
2648 if ( isset( $ignore_index[$alias] ) ) { // has IGNORE INDEX?
2649 $ignore = $this->ignoreIndexClause(
2650 implode( ',', (array)$ignore_index[$alias] ) );
2651 if ( $ignore != '' ) {
2652 $tableClause .= ' ' . $ignore;
2655 $on = $this->makeList( (array)$conds, self
::LIST_AND
);
2657 $tableClause .= ' ON (' . $on . ')';
2660 $retJOIN[] = $tableClause;
2661 } elseif ( isset( $use_index[$alias] ) ) {
2662 // Is there an INDEX clause for this table?
2663 $tableClause = $joinedTable;
2664 $tableClause .= ' ' . $this->useIndexClause(
2665 implode( ',', (array)$use_index[$alias] )
2668 $ret[] = $tableClause;
2669 } elseif ( isset( $ignore_index[$alias] ) ) {
2670 // Is there an INDEX clause for this table?
2671 $tableClause = $joinedTable;
2672 $tableClause .= ' ' . $this->ignoreIndexClause(
2673 implode( ',', (array)$ignore_index[$alias] )
2676 $ret[] = $tableClause;
2678 $tableClause = $joinedTable;
2680 $ret[] = $tableClause;
2684 // We can't separate explicit JOIN clauses with ',', use ' ' for those
2685 $implicitJoins = implode( ',', $ret );
2686 $explicitJoins = implode( ' ', $retJOIN );
2688 // Compile our final table clause
2689 return implode( ' ', [ $implicitJoins, $explicitJoins ] );
2693 * Allows for index remapping in queries where this is not consistent across DBMS
2695 * @param string $index
2698 protected function indexName( $index ) {
2699 return $this->indexAliases
[$index] ??
$index;
2702 public function addQuotes( $s ) {
2703 if ( $s instanceof Blob
) {
2706 if ( $s === null ) {
2708 } elseif ( is_bool( $s ) ) {
2711 # This will also quote numeric values. This should be harmless,
2712 # and protects against weird problems that occur when they really
2713 # _are_ strings such as article titles and string->number->string
2714 # conversion is not 1:1.
2715 return "'" . $this->strencode( $s ) . "'";
2719 public function addIdentifierQuotes( $s ) {
2720 return '"' . str_replace( '"', '""', $s ) . '"';
2724 * Returns if the given identifier looks quoted or not according to
2725 * the database convention for quoting identifiers .
2727 * @note Do not use this to determine if untrusted input is safe.
2728 * A malicious user can trick this function.
2729 * @param string $name
2732 public function isQuotedIdentifier( $name ) {
2733 return $name[0] == '"' && substr( $name, -1, 1 ) == '"';
2738 * @param string $escapeChar
2741 protected function escapeLikeInternal( $s, $escapeChar = '`' ) {
2742 return str_replace( [ $escapeChar, '%', '_' ],
2743 [ "{$escapeChar}{$escapeChar}", "{$escapeChar}%", "{$escapeChar}_" ],
2747 public function buildLike() {
2748 $params = func_get_args();
2750 if ( count( $params ) > 0 && is_array( $params[0] ) ) {
2751 $params = $params[0];
2756 // We use ` instead of \ as the default LIKE escape character, since addQuotes()
2757 // may escape backslashes, creating problems of double escaping. The `
2758 // character has good cross-DBMS compatibility, avoiding special operators
2759 // in MS SQL like ^ and %
2762 foreach ( $params as $value ) {
2763 if ( $value instanceof LikeMatch
) {
2764 $s .= $value->toString();
2766 $s .= $this->escapeLikeInternal( $value, $escapeChar );
2771 $this->addQuotes( $s ) . ' ESCAPE ' . $this->addQuotes( $escapeChar ) . ' ';
2774 public function anyChar() {
2775 return new LikeMatch( '_' );
2778 public function anyString() {
2779 return new LikeMatch( '%' );
2782 public function nextSequenceValue( $seqName ) {
2787 * USE INDEX clause. Unlikely to be useful for anything but MySQL. This
2788 * is only needed because a) MySQL must be as efficient as possible due to
2789 * its use on Wikipedia, and b) MySQL 4.0 is kind of dumb sometimes about
2790 * which index to pick. Anyway, other databases might have different
2791 * indexes on a given table. So don't bother overriding this unless you're
2793 * @param string $index
2796 public function useIndexClause( $index ) {
2801 * IGNORE INDEX clause. Unlikely to be useful for anything but MySQL. This
2802 * is only needed because a) MySQL must be as efficient as possible due to
2803 * its use on Wikipedia, and b) MySQL 4.0 is kind of dumb sometimes about
2804 * which index to pick. Anyway, other databases might have different
2805 * indexes on a given table. So don't bother overriding this unless you're
2807 * @param string $index
2810 public function ignoreIndexClause( $index ) {
2814 public function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__
) {
2815 if ( count( $rows ) == 0 ) {
2819 $uniqueIndexes = (array)$uniqueIndexes;
2821 if ( !is_array( reset( $rows ) ) ) {
2826 $this->startAtomic( $fname, self
::ATOMIC_CANCELABLE
);
2827 $affectedRowCount = 0;
2828 foreach ( $rows as $row ) {
2829 // Delete rows which collide with this one
2830 $indexWhereClauses = [];
2831 foreach ( $uniqueIndexes as $index ) {
2832 $indexColumns = (array)$index;
2833 $indexRowValues = array_intersect_key( $row, array_flip( $indexColumns ) );
2834 if ( count( $indexRowValues ) != count( $indexColumns ) ) {
2835 throw new DBUnexpectedError(
2837 'New record does not provide all values for unique key (' .
2838 implode( ', ', $indexColumns ) . ')'
2840 } elseif ( in_array( null, $indexRowValues, true ) ) {
2841 throw new DBUnexpectedError(
2843 'New record has a null value for unique key (' .
2844 implode( ', ', $indexColumns ) . ')'
2847 $indexWhereClauses[] = $this->makeList( $indexRowValues, LIST_AND
);
2850 if ( $indexWhereClauses ) {
2851 $this->delete( $table, $this->makeList( $indexWhereClauses, LIST_OR
), $fname );
2852 $affectedRowCount +
= $this->affectedRows();
2855 // Now insert the row
2856 $this->insert( $table, $row, $fname );
2857 $affectedRowCount +
= $this->affectedRows();
2859 $this->endAtomic( $fname );
2860 $this->affectedRowCount
= $affectedRowCount;
2861 } catch ( Exception
$e ) {
2862 $this->cancelAtomic( $fname );
2868 * REPLACE query wrapper for MySQL and SQLite, which have a native REPLACE
2871 * @param string $table Table name
2872 * @param array|string $rows Row(s) to insert
2873 * @param string $fname Caller function name
2875 protected function nativeReplace( $table, $rows, $fname ) {
2876 $table = $this->tableName( $table );
2879 if ( !is_array( reset( $rows ) ) ) {
2883 $sql = "REPLACE INTO $table (" . implode( ',', array_keys( $rows[0] ) ) . ') VALUES ';
2886 foreach ( $rows as $row ) {
2893 $sql .= '(' . $this->makeList( $row ) . ')';
2896 $this->query( $sql, $fname );
2899 public function upsert( $table, array $rows, $uniqueIndexes, array $set,
2902 if ( $rows === [] ) {
2903 return true; // nothing to do
2906 $uniqueIndexes = (array)$uniqueIndexes;
2907 if ( !is_array( reset( $rows ) ) ) {
2911 if ( count( $uniqueIndexes ) ) {
2912 $clauses = []; // list WHERE clauses that each identify a single row
2913 foreach ( $rows as $row ) {
2914 foreach ( $uniqueIndexes as $index ) {
2915 $index = is_array( $index ) ?
$index : [ $index ]; // columns
2916 $rowKey = []; // unique key to this row
2917 foreach ( $index as $column ) {
2918 $rowKey[$column] = $row[$column];
2920 $clauses[] = $this->makeList( $rowKey, self
::LIST_AND
);
2923 $where = [ $this->makeList( $clauses, self
::LIST_OR
) ];
2928 $affectedRowCount = 0;
2930 $this->startAtomic( $fname, self
::ATOMIC_CANCELABLE
);
2931 # Update any existing conflicting row(s)
2932 if ( $where !== false ) {
2933 $this->update( $table, $set, $where, $fname );
2934 $affectedRowCount +
= $this->affectedRows();
2936 # Now insert any non-conflicting row(s)
2937 $this->insert( $table, $rows, $fname, [ 'IGNORE' ] );
2938 $affectedRowCount +
= $this->affectedRows();
2939 $this->endAtomic( $fname );
2940 $this->affectedRowCount
= $affectedRowCount;
2941 } catch ( Exception
$e ) {
2942 $this->cancelAtomic( $fname );
2949 public function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds,
2953 throw new DBUnexpectedError( $this, __METHOD__
. ' called with empty $conds' );
2956 $delTable = $this->tableName( $delTable );
2957 $joinTable = $this->tableName( $joinTable );
2958 $sql = "DELETE FROM $delTable WHERE $delVar IN (SELECT $joinVar FROM $joinTable ";
2959 if ( $conds != '*' ) {
2960 $sql .= 'WHERE ' . $this->makeList( $conds, self
::LIST_AND
);
2964 $this->query( $sql, $fname );
2967 public function textFieldSize( $table, $field ) {
2968 $table = $this->tableName( $table );
2969 $sql = "SHOW COLUMNS FROM $table LIKE \"$field\";";
2970 $res = $this->query( $sql, __METHOD__
);
2971 $row = $this->fetchObject( $res );
2975 if ( preg_match( '/\((.*)\)/', $row->Type
, $m ) ) {
2984 public function delete( $table, $conds, $fname = __METHOD__
) {
2986 throw new DBUnexpectedError( $this, __METHOD__
. ' called with no conditions' );
2989 $table = $this->tableName( $table );
2990 $sql = "DELETE FROM $table";
2992 if ( $conds != '*' ) {
2993 if ( is_array( $conds ) ) {
2994 $conds = $this->makeList( $conds, self
::LIST_AND
);
2996 $sql .= ' WHERE ' . $conds;
2999 $this->query( $sql, $fname );
3004 final public function insertSelect(
3005 $destTable, $srcTable, $varMap, $conds,
3006 $fname = __METHOD__
, $insertOptions = [], $selectOptions = [], $selectJoinConds = []
3008 static $hints = [ 'NO_AUTO_COLUMNS' ];
3010 $insertOptions = (array)$insertOptions;
3011 $selectOptions = (array)$selectOptions;
3013 if ( $this->cliMode
&& $this->isInsertSelectSafe( $insertOptions, $selectOptions ) ) {
3014 // For massive migrations with downtime, we don't want to select everything
3015 // into memory and OOM, so do all this native on the server side if possible.
3016 $this->nativeInsertSelect(
3022 array_diff( $insertOptions, $hints ),
3027 $this->nonNativeInsertSelect(
3033 array_diff( $insertOptions, $hints ),
3043 * @param array $insertOptions INSERT options
3044 * @param array $selectOptions SELECT options
3045 * @return bool Whether an INSERT SELECT with these options will be replication safe
3048 protected function isInsertSelectSafe( array $insertOptions, array $selectOptions ) {
3053 * Implementation of insertSelect() based on select() and insert()
3055 * @see IDatabase::insertSelect()
3057 * @param string $destTable
3058 * @param string|array $srcTable
3059 * @param array $varMap
3060 * @param array $conds
3061 * @param string $fname
3062 * @param array $insertOptions
3063 * @param array $selectOptions
3064 * @param array $selectJoinConds
3066 protected function nonNativeInsertSelect( $destTable, $srcTable, $varMap, $conds,
3067 $fname = __METHOD__
,
3068 $insertOptions = [], $selectOptions = [], $selectJoinConds = []
3070 // For web requests, do a locking SELECT and then INSERT. This puts the SELECT burden
3071 // on only the master (without needing row-based-replication). It also makes it easy to
3072 // know how big the INSERT is going to be.
3074 foreach ( $varMap as $dstColumn => $sourceColumnOrSql ) {
3075 $fields[] = $this->fieldNameWithAlias( $sourceColumnOrSql, $dstColumn );
3077 $selectOptions[] = 'FOR UPDATE';
3078 $res = $this->select(
3079 $srcTable, implode( ',', $fields ), $conds, $fname, $selectOptions, $selectJoinConds
3086 $affectedRowCount = 0;
3087 $this->startAtomic( $fname, self
::ATOMIC_CANCELABLE
);
3090 foreach ( $res as $row ) {
3091 $rows[] = (array)$row;
3093 // Avoid inserts that are too huge
3094 if ( count( $rows ) >= $this->nonNativeInsertSelectBatchSize
) {
3095 $ok = $this->insert( $destTable, $rows, $fname, $insertOptions );
3099 $affectedRowCount +
= $this->affectedRows();
3103 if ( $rows && $ok ) {
3104 $ok = $this->insert( $destTable, $rows, $fname, $insertOptions );
3106 $affectedRowCount +
= $this->affectedRows();
3110 $this->endAtomic( $fname );
3111 $this->affectedRowCount
= $affectedRowCount;
3113 $this->cancelAtomic( $fname );
3115 } catch ( Exception
$e ) {
3116 $this->cancelAtomic( $fname );
3122 * Native server-side implementation of insertSelect() for situations where
3123 * we don't want to select everything into memory
3125 * @see IDatabase::insertSelect()
3126 * @param string $destTable
3127 * @param string|array $srcTable
3128 * @param array $varMap
3129 * @param array $conds
3130 * @param string $fname
3131 * @param array $insertOptions
3132 * @param array $selectOptions
3133 * @param array $selectJoinConds
3135 protected function nativeInsertSelect( $destTable, $srcTable, $varMap, $conds,
3136 $fname = __METHOD__
,
3137 $insertOptions = [], $selectOptions = [], $selectJoinConds = []
3139 $destTable = $this->tableName( $destTable );
3141 if ( !is_array( $insertOptions ) ) {
3142 $insertOptions = [ $insertOptions ];
3145 $insertOptions = $this->makeInsertOptions( $insertOptions );
3147 $selectSql = $this->selectSQLText(
3149 array_values( $varMap ),
3156 $sql = "INSERT $insertOptions" .
3157 " INTO $destTable (" . implode( ',', array_keys( $varMap ) ) . ') ' .
3160 $this->query( $sql, $fname );
3163 public function limitResult( $sql, $limit, $offset = false ) {
3164 if ( !is_numeric( $limit ) ) {
3165 throw new DBUnexpectedError( $this,
3166 "Invalid non-numeric limit passed to limitResult()\n" );
3168 // This version works in MySQL and SQLite. It will very likely need to be
3169 // overridden for most other RDBMS subclasses.
3170 return "$sql LIMIT "
3171 . ( ( is_numeric( $offset ) && $offset != 0 ) ?
"{$offset}," : "" )
3175 public function unionSupportsOrderAndLimit() {
3176 return true; // True for almost every DB supported
3179 public function unionQueries( $sqls, $all ) {
3180 $glue = $all ?
') UNION ALL (' : ') UNION (';
3182 return '(' . implode( $glue, $sqls ) . ')';
3185 public function unionConditionPermutations(
3186 $table, $vars, array $permute_conds, $extra_conds = '', $fname = __METHOD__
,
3187 $options = [], $join_conds = []
3189 // First, build the Cartesian product of $permute_conds
3191 foreach ( $permute_conds as $field => $values ) {
3193 // Skip empty $values
3196 $values = array_unique( $values ); // For sanity
3198 foreach ( $conds as $cond ) {
3199 foreach ( $values as $value ) {
3200 $cond[$field] = $value;
3201 $newConds[] = $cond; // Arrays are by-value, not by-reference, so this works
3207 $extra_conds = $extra_conds === '' ?
[] : (array)$extra_conds;
3209 // If there's just one condition and no subordering, hand off to
3210 // selectSQLText directly.
3211 if ( count( $conds ) === 1 &&
3212 ( !isset( $options['INNER ORDER BY'] ) ||
!$this->unionSupportsOrderAndLimit() )
3214 return $this->selectSQLText(
3215 $table, $vars, $conds[0] +
$extra_conds, $fname, $options, $join_conds
3219 // Otherwise, we need to pull out the order and limit to apply after
3220 // the union. Then build the SQL queries for each set of conditions in
3221 // $conds. Then union them together (using UNION ALL, because the
3222 // product *should* already be distinct).
3223 $orderBy = $this->makeOrderBy( $options );
3224 $limit = $options['LIMIT'] ??
null;
3225 $offset = $options['OFFSET'] ??
false;
3226 $all = empty( $options['NOTALL'] ) && !in_array( 'NOTALL', $options );
3227 if ( !$this->unionSupportsOrderAndLimit() ) {
3228 unset( $options['ORDER BY'], $options['LIMIT'], $options['OFFSET'] );
3230 if ( array_key_exists( 'INNER ORDER BY', $options ) ) {
3231 $options['ORDER BY'] = $options['INNER ORDER BY'];
3233 if ( $limit !== null && is_numeric( $offset ) && $offset != 0 ) {
3234 // We need to increase the limit by the offset rather than
3235 // using the offset directly, otherwise it'll skip incorrectly
3236 // in the subqueries.
3237 $options['LIMIT'] = $limit +
$offset;
3238 unset( $options['OFFSET'] );
3243 foreach ( $conds as $cond ) {
3244 $sqls[] = $this->selectSQLText(
3245 $table, $vars, $cond +
$extra_conds, $fname, $options, $join_conds
3248 $sql = $this->unionQueries( $sqls, $all ) . $orderBy;
3249 if ( $limit !== null ) {
3250 $sql = $this->limitResult( $sql, $limit, $offset );
3256 public function conditional( $cond, $trueVal, $falseVal ) {
3257 if ( is_array( $cond ) ) {
3258 $cond = $this->makeList( $cond, self
::LIST_AND
);
3261 return " (CASE WHEN $cond THEN $trueVal ELSE $falseVal END) ";
3264 public function strreplace( $orig, $old, $new ) {
3265 return "REPLACE({$orig}, {$old}, {$new})";
3268 public function getServerUptime() {
3272 public function wasDeadlock() {
3276 public function wasLockTimeout() {
3280 public function wasConnectionLoss() {
3281 return $this->wasConnectionError( $this->lastErrno() );
3284 public function wasReadOnlyError() {
3288 public function wasErrorReissuable() {
3290 $this->wasDeadlock() ||
3291 $this->wasLockTimeout() ||
3292 $this->wasConnectionLoss()
3297 * Do not use this method outside of Database/DBError classes
3299 * @param int|string $errno
3300 * @return bool Whether the given query error was a connection drop
3302 public function wasConnectionError( $errno ) {
3307 * @return bool Whether it is known that the last query error only caused statement rollback
3308 * @note This is for backwards compatibility for callers catching DBError exceptions in
3309 * order to ignore problems like duplicate key errors or foriegn key violations
3312 protected function wasKnownStatementRollbackError() {
3313 return false; // don't know; it could have caused a transaction rollback
3316 public function deadlockLoop() {
3317 $args = func_get_args();
3318 $function = array_shift( $args );
3319 $tries = self
::DEADLOCK_TRIES
;
3321 $this->begin( __METHOD__
);
3324 /** @var Exception $e */
3328 $retVal = $function( ...$args );
3330 } catch ( DBQueryError
$e ) {
3331 if ( $this->wasDeadlock() ) {
3332 // Retry after a randomized delay
3333 usleep( mt_rand( self
::DEADLOCK_DELAY_MIN
, self
::DEADLOCK_DELAY_MAX
) );
3335 // Throw the error back up
3339 } while ( --$tries > 0 );
3341 if ( $tries <= 0 ) {
3342 // Too many deadlocks; give up
3343 $this->rollback( __METHOD__
);
3346 $this->commit( __METHOD__
);
3352 public function masterPosWait( DBMasterPos
$pos, $timeout ) {
3353 # Real waits are implemented in the subclass.
3357 public function getReplicaPos() {
3362 public function getMasterPos() {
3367 public function serverIsReadOnly() {
3371 final public function onTransactionResolution( callable
$callback, $fname = __METHOD__
) {
3372 if ( !$this->trxLevel
) {
3373 throw new DBUnexpectedError( $this, "No transaction is active." );
3375 $this->trxEndCallbacks
[] = [ $callback, $fname, $this->currentAtomicSectionId() ];
3378 final public function onTransactionCommitOrIdle( callable
$callback, $fname = __METHOD__
) {
3379 if ( !$this->trxLevel
&& $this->getTransactionRoundId() ) {
3380 // Start an implicit transaction similar to how query() does
3381 $this->begin( __METHOD__
, self
::TRANSACTION_INTERNAL
);
3382 $this->trxAutomatic
= true;
3385 $this->trxIdleCallbacks
[] = [ $callback, $fname, $this->currentAtomicSectionId() ];
3386 if ( !$this->trxLevel
) {
3387 $this->runOnTransactionIdleCallbacks( self
::TRIGGER_IDLE
);
3391 final public function onTransactionIdle( callable
$callback, $fname = __METHOD__
) {
3392 $this->onTransactionCommitOrIdle( $callback, $fname );
3395 final public function onTransactionPreCommitOrIdle( callable
$callback, $fname = __METHOD__
) {
3396 if ( !$this->trxLevel
&& $this->getTransactionRoundId() ) {
3397 // Start an implicit transaction similar to how query() does
3398 $this->begin( __METHOD__
, self
::TRANSACTION_INTERNAL
);
3399 $this->trxAutomatic
= true;
3402 if ( $this->trxLevel
) {
3403 $this->trxPreCommitCallbacks
[] = [ $callback, $fname, $this->currentAtomicSectionId() ];
3405 // No transaction is active nor will start implicitly, so make one for this callback
3406 $this->startAtomic( __METHOD__
, self
::ATOMIC_CANCELABLE
);
3409 $this->endAtomic( __METHOD__
);
3410 } catch ( Exception
$e ) {
3411 $this->cancelAtomic( __METHOD__
);
3418 * @return AtomicSectionIdentifier|null ID of the topmost atomic section level
3420 private function currentAtomicSectionId() {
3421 if ( $this->trxLevel
&& $this->trxAtomicLevels
) {
3422 $levelInfo = end( $this->trxAtomicLevels
);
3424 return $levelInfo[1];
3431 * @param AtomicSectionIdentifier $old
3432 * @param AtomicSectionIdentifier $new
3434 private function reassignCallbacksForSection(
3435 AtomicSectionIdentifier
$old, AtomicSectionIdentifier
$new
3437 foreach ( $this->trxPreCommitCallbacks
as $key => $info ) {
3438 if ( $info[2] === $old ) {
3439 $this->trxPreCommitCallbacks
[$key][2] = $new;
3442 foreach ( $this->trxIdleCallbacks
as $key => $info ) {
3443 if ( $info[2] === $old ) {
3444 $this->trxIdleCallbacks
[$key][2] = $new;
3447 foreach ( $this->trxEndCallbacks
as $key => $info ) {
3448 if ( $info[2] === $old ) {
3449 $this->trxEndCallbacks
[$key][2] = $new;
3455 * @param AtomicSectionIdentifier[] $sectionIds ID of an actual savepoint
3456 * @throws UnexpectedValueException
3458 private function modifyCallbacksForCancel( array $sectionIds ) {
3459 // Cancel the "on commit" callbacks owned by this savepoint
3460 $this->trxIdleCallbacks
= array_filter(
3461 $this->trxIdleCallbacks
,
3462 function ( $entry ) use ( $sectionIds ) {
3463 return !in_array( $entry[2], $sectionIds, true );
3466 $this->trxPreCommitCallbacks
= array_filter(
3467 $this->trxPreCommitCallbacks
,
3468 function ( $entry ) use ( $sectionIds ) {
3469 return !in_array( $entry[2], $sectionIds, true );
3472 // Make "on resolution" callbacks owned by this savepoint to perceive a rollback
3473 foreach ( $this->trxEndCallbacks
as $key => $entry ) {
3474 if ( in_array( $entry[2], $sectionIds, true ) ) {
3475 $callback = $entry[0];
3476 $this->trxEndCallbacks
[$key][0] = function () use ( $callback ) {
3477 return $callback( self
::TRIGGER_ROLLBACK
, $this );
3483 final public function setTransactionListener( $name, callable
$callback = null ) {
3485 $this->trxRecurringCallbacks
[$name] = $callback;
3487 unset( $this->trxRecurringCallbacks
[$name] );
3492 * Whether to disable running of post-COMMIT/ROLLBACK callbacks
3494 * This method should not be used outside of Database/LoadBalancer
3496 * @param bool $suppress
3499 final public function setTrxEndCallbackSuppression( $suppress ) {
3500 $this->trxEndCallbacksSuppressed
= $suppress;
3504 * Actually consume and run any "on transaction idle/resolution" callbacks.
3506 * This method should not be used outside of Database/LoadBalancer
3508 * @param int $trigger IDatabase::TRIGGER_* constant
3509 * @return int Number of callbacks attempted
3513 public function runOnTransactionIdleCallbacks( $trigger ) {
3514 if ( $this->trxLevel
) { // sanity
3515 throw new DBUnexpectedError( $this, __METHOD__
. ': a transaction is still open.' );
3518 if ( $this->trxEndCallbacksSuppressed
) {
3523 $autoTrx = $this->getFlag( self
::DBO_TRX
); // automatic begin() enabled?
3524 /** @var Exception $e */
3525 $e = null; // first exception
3526 do { // callbacks may add callbacks :)
3527 $callbacks = array_merge(
3528 $this->trxIdleCallbacks
,
3529 $this->trxEndCallbacks
// include "transaction resolution" callbacks
3531 $this->trxIdleCallbacks
= []; // consumed (and recursion guard)
3532 $this->trxEndCallbacks
= []; // consumed (recursion guard)
3533 foreach ( $callbacks as $callback ) {
3535 list( $phpCallback ) = $callback;
3536 $this->clearFlag( self
::DBO_TRX
); // make each query its own transaction
3538 // @phan-suppress-next-line PhanParamTooManyCallable
3539 call_user_func( $phpCallback, $trigger, $this );
3540 } catch ( Exception
$ex ) {
3541 call_user_func( $this->errorLogger
, $ex );
3543 // Some callbacks may use startAtomic/endAtomic, so make sure
3544 // their transactions are ended so other callbacks don't fail
3545 if ( $this->trxLevel() ) {
3546 $this->rollback( __METHOD__
, self
::FLUSHING_INTERNAL
);
3550 $this->setFlag( self
::DBO_TRX
); // restore automatic begin()
3552 $this->clearFlag( self
::DBO_TRX
); // restore auto-commit
3556 } while ( count( $this->trxIdleCallbacks
) );
3558 if ( $e instanceof Exception
) {
3559 throw $e; // re-throw any first exception
3566 * Actually consume and run any "on transaction pre-commit" callbacks.
3568 * This method should not be used outside of Database/LoadBalancer
3571 * @return int Number of callbacks attempted
3574 public function runOnTransactionPreCommitCallbacks() {
3577 $e = null; // first exception
3578 do { // callbacks may add callbacks :)
3579 $callbacks = $this->trxPreCommitCallbacks
;
3580 $this->trxPreCommitCallbacks
= []; // consumed (and recursion guard)
3581 foreach ( $callbacks as $callback ) {
3584 list( $phpCallback ) = $callback;
3585 $phpCallback( $this );
3586 } catch ( Exception
$ex ) {
3587 ( $this->errorLogger
)( $ex );
3591 } while ( count( $this->trxPreCommitCallbacks
) );
3593 if ( $e instanceof Exception
) {
3594 throw $e; // re-throw any first exception
3601 * Actually run any "transaction listener" callbacks.
3603 * This method should not be used outside of Database/LoadBalancer
3605 * @param int $trigger IDatabase::TRIGGER_* constant
3609 public function runTransactionListenerCallbacks( $trigger ) {
3610 if ( $this->trxEndCallbacksSuppressed
) {
3614 /** @var Exception $e */
3615 $e = null; // first exception
3617 foreach ( $this->trxRecurringCallbacks
as $phpCallback ) {
3619 $phpCallback( $trigger, $this );
3620 } catch ( Exception
$ex ) {
3621 ( $this->errorLogger
)( $ex );
3626 if ( $e instanceof Exception
) {
3627 throw $e; // re-throw any first exception
3632 * Create a savepoint
3634 * This is used internally to implement atomic sections. It should not be
3638 * @param string $identifier Identifier for the savepoint
3639 * @param string $fname Calling function name
3641 protected function doSavepoint( $identifier, $fname ) {
3642 $this->query( 'SAVEPOINT ' . $this->addIdentifierQuotes( $identifier ), $fname );
3646 * Release a savepoint
3648 * This is used internally to implement atomic sections. It should not be
3652 * @param string $identifier Identifier for the savepoint
3653 * @param string $fname Calling function name
3655 protected function doReleaseSavepoint( $identifier, $fname ) {
3656 $this->query( 'RELEASE SAVEPOINT ' . $this->addIdentifierQuotes( $identifier ), $fname );
3660 * Rollback to a savepoint
3662 * This is used internally to implement atomic sections. It should not be
3666 * @param string $identifier Identifier for the savepoint
3667 * @param string $fname Calling function name
3669 protected function doRollbackToSavepoint( $identifier, $fname ) {
3670 $this->query( 'ROLLBACK TO SAVEPOINT ' . $this->addIdentifierQuotes( $identifier ), $fname );
3674 * @param string $fname
3677 private function nextSavepointId( $fname ) {
3678 $savepointId = self
::$SAVEPOINT_PREFIX . ++
$this->trxAtomicCounter
;
3679 if ( strlen( $savepointId ) > 30 ) {
3680 // 30 == Oracle's identifier length limit (pre 12c)
3681 // With a 22 character prefix, that puts the highest number at 99999999.
3682 throw new DBUnexpectedError(
3684 'There have been an excessively large number of atomic sections in a transaction'
3685 . " started by $this->trxFname (at $fname)"
3689 return $savepointId;
3692 final public function startAtomic(
3693 $fname = __METHOD__
, $cancelable = self
::ATOMIC_NOT_CANCELABLE
3695 $savepointId = $cancelable === self
::ATOMIC_CANCELABLE ? self
::$NOT_APPLICABLE : null;
3697 if ( !$this->trxLevel
) {
3698 $this->begin( $fname, self
::TRANSACTION_INTERNAL
); // sets trxAutomatic
3699 // If DBO_TRX is set, a series of startAtomic/endAtomic pairs will result
3700 // in all changes being in one transaction to keep requests transactional.
3701 if ( $this->getFlag( self
::DBO_TRX
) ) {
3702 // Since writes could happen in between the topmost atomic sections as part
3703 // of the transaction, those sections will need savepoints.
3704 $savepointId = $this->nextSavepointId( $fname );
3705 $this->doSavepoint( $savepointId, $fname );
3707 $this->trxAutomaticAtomic
= true;
3709 } elseif ( $cancelable === self
::ATOMIC_CANCELABLE
) {
3710 $savepointId = $this->nextSavepointId( $fname );
3711 $this->doSavepoint( $savepointId, $fname );
3714 $sectionId = new AtomicSectionIdentifier
;
3715 $this->trxAtomicLevels
[] = [ $fname, $sectionId, $savepointId ];
3716 $this->queryLogger
->debug( 'startAtomic: entering level ' .
3717 ( count( $this->trxAtomicLevels
) - 1 ) . " ($fname)" );
3722 final public function endAtomic( $fname = __METHOD__
) {
3723 if ( !$this->trxLevel ||
!$this->trxAtomicLevels
) {
3724 throw new DBUnexpectedError( $this, "No atomic section is open (got $fname)." );
3727 // Check if the current section matches $fname
3728 $pos = count( $this->trxAtomicLevels
) - 1;
3729 list( $savedFname, $sectionId, $savepointId ) = $this->trxAtomicLevels
[$pos];
3730 $this->queryLogger
->debug( "endAtomic: leaving level $pos ($fname)" );
3732 if ( $savedFname !== $fname ) {
3733 throw new DBUnexpectedError(
3735 "Invalid atomic section ended (got $fname but expected $savedFname)."
3739 // Remove the last section (no need to re-index the array)
3740 array_pop( $this->trxAtomicLevels
);
3742 if ( !$this->trxAtomicLevels
&& $this->trxAutomaticAtomic
) {
3743 $this->commit( $fname, self
::FLUSHING_INTERNAL
);
3744 } elseif ( $savepointId !== null && $savepointId !== self
::$NOT_APPLICABLE ) {
3745 $this->doReleaseSavepoint( $savepointId, $fname );
3748 // Hoist callback ownership for callbacks in the section that just ended;
3749 // all callbacks should have an owner that is present in trxAtomicLevels.
3750 $currentSectionId = $this->currentAtomicSectionId();
3751 if ( $currentSectionId ) {
3752 $this->reassignCallbacksForSection( $sectionId, $currentSectionId );
3756 final public function cancelAtomic(
3757 $fname = __METHOD__
, AtomicSectionIdentifier
$sectionId = null
3759 if ( !$this->trxLevel ||
!$this->trxAtomicLevels
) {
3760 throw new DBUnexpectedError( $this, "No atomic section is open (got $fname)." );
3763 $excisedFnames = [];
3764 if ( $sectionId !== null ) {
3765 // Find the (last) section with the given $sectionId
3767 foreach ( $this->trxAtomicLevels
as $i => list( $asFname, $asId, $spId ) ) {
3768 if ( $asId === $sectionId ) {
3773 throw new DBUnexpectedError( $this, "Atomic section not found (for $fname)" );
3775 // Remove all descendant sections and re-index the array
3777 $len = count( $this->trxAtomicLevels
);
3778 for ( $i = $pos +
1; $i < $len; ++
$i ) {
3779 $excisedFnames[] = $this->trxAtomicLevels
[$i][0];
3780 $excisedIds[] = $this->trxAtomicLevels
[$i][1];
3782 $this->trxAtomicLevels
= array_slice( $this->trxAtomicLevels
, 0, $pos +
1 );
3783 $this->modifyCallbacksForCancel( $excisedIds );
3786 // Check if the current section matches $fname
3787 $pos = count( $this->trxAtomicLevels
) - 1;
3788 list( $savedFname, $savedSectionId, $savepointId ) = $this->trxAtomicLevels
[$pos];
3790 if ( $excisedFnames ) {
3791 $this->queryLogger
->debug( "cancelAtomic: canceling level $pos ($savedFname) " .
3792 "and descendants " . implode( ', ', $excisedFnames ) );
3794 $this->queryLogger
->debug( "cancelAtomic: canceling level $pos ($savedFname)" );
3797 if ( $savedFname !== $fname ) {
3798 throw new DBUnexpectedError(
3800 "Invalid atomic section ended (got $fname but expected $savedFname)."
3804 // Remove the last section (no need to re-index the array)
3805 array_pop( $this->trxAtomicLevels
);
3806 $this->modifyCallbacksForCancel( [ $savedSectionId ] );
3808 if ( $savepointId !== null ) {
3809 // Rollback the transaction to the state just before this atomic section
3810 if ( $savepointId === self
::$NOT_APPLICABLE ) {
3811 $this->rollback( $fname, self
::FLUSHING_INTERNAL
);
3813 $this->doRollbackToSavepoint( $savepointId, $fname );
3814 $this->trxStatus
= self
::STATUS_TRX_OK
; // no exception; recovered
3815 $this->trxStatusIgnoredCause
= null;
3817 } elseif ( $this->trxStatus
> self
::STATUS_TRX_ERROR
) {
3818 // Put the transaction into an error state if it's not already in one
3819 $this->trxStatus
= self
::STATUS_TRX_ERROR
;
3820 $this->trxStatusCause
= new DBUnexpectedError(
3822 "Uncancelable atomic section canceled (got $fname)."
3826 $this->affectedRowCount
= 0; // for the sake of consistency
3829 final public function doAtomicSection(
3830 $fname, callable
$callback, $cancelable = self
::ATOMIC_NOT_CANCELABLE
3832 $sectionId = $this->startAtomic( $fname, $cancelable );
3834 $res = $callback( $this, $fname );
3835 } catch ( Exception
$e ) {
3836 $this->cancelAtomic( $fname, $sectionId );
3840 $this->endAtomic( $fname );
3845 final public function begin( $fname = __METHOD__
, $mode = self
::TRANSACTION_EXPLICIT
) {
3846 static $modes = [ self
::TRANSACTION_EXPLICIT
, self
::TRANSACTION_INTERNAL
];
3847 if ( !in_array( $mode, $modes, true ) ) {
3848 throw new DBUnexpectedError( $this, "$fname: invalid mode parameter '$mode'." );
3851 // Protect against mismatched atomic section, transaction nesting, and snapshot loss
3852 if ( $this->trxLevel
) {
3853 if ( $this->trxAtomicLevels
) {
3854 $levels = $this->flatAtomicSectionList();
3855 $msg = "$fname: Got explicit BEGIN while atomic section(s) $levels are open.";
3856 throw new DBUnexpectedError( $this, $msg );
3857 } elseif ( !$this->trxAutomatic
) {
3858 $msg = "$fname: Explicit transaction already active (from {$this->trxFname}).";
3859 throw new DBUnexpectedError( $this, $msg );
3861 $msg = "$fname: Implicit transaction already active (from {$this->trxFname}).";
3862 throw new DBUnexpectedError( $this, $msg );
3864 } elseif ( $this->getFlag( self
::DBO_TRX
) && $mode !== self
::TRANSACTION_INTERNAL
) {
3865 $msg = "$fname: Implicit transaction expected (DBO_TRX set).";
3866 throw new DBUnexpectedError( $this, $msg );
3869 $this->assertHasConnectionHandle();
3871 $this->doBegin( $fname );
3872 $this->trxStatus
= self
::STATUS_TRX_OK
;
3873 $this->trxStatusIgnoredCause
= null;
3874 $this->trxAtomicCounter
= 0;
3875 $this->trxTimestamp
= microtime( true );
3876 $this->trxFname
= $fname;
3877 $this->trxDoneWrites
= false;
3878 $this->trxAutomaticAtomic
= false;
3879 $this->trxAtomicLevels
= [];
3880 $this->trxShortId
= sprintf( '%06x', mt_rand( 0, 0xffffff ) );
3881 $this->trxWriteDuration
= 0.0;
3882 $this->trxWriteQueryCount
= 0;
3883 $this->trxWriteAffectedRows
= 0;
3884 $this->trxWriteAdjDuration
= 0.0;
3885 $this->trxWriteAdjQueryCount
= 0;
3886 $this->trxWriteCallers
= [];
3887 // First SELECT after BEGIN will establish the snapshot in REPEATABLE-READ.
3888 // Get an estimate of the replication lag before any such queries.
3889 $this->trxReplicaLag
= null; // clear cached value first
3890 $this->trxReplicaLag
= $this->getApproximateLagStatus()['lag'];
3891 // T147697: make explicitTrxActive() return true until begin() finishes. This way, no
3892 // caller will think its OK to muck around with the transaction just because startAtomic()
3893 // has not yet completed (e.g. setting trxAtomicLevels).
3894 $this->trxAutomatic
= ( $mode === self
::TRANSACTION_INTERNAL
);
3898 * Issues the BEGIN command to the database server.
3900 * @see Database::begin()
3901 * @param string $fname
3903 protected function doBegin( $fname ) {
3904 $this->query( 'BEGIN', $fname );
3905 $this->trxLevel
= 1;
3908 final public function commit( $fname = __METHOD__
, $flush = self
::FLUSHING_ONE
) {
3909 static $modes = [ self
::FLUSHING_ONE
, self
::FLUSHING_ALL_PEERS
, self
::FLUSHING_INTERNAL
];
3910 if ( !in_array( $flush, $modes, true ) ) {
3911 throw new DBUnexpectedError( $this, "$fname: invalid flush parameter '$flush'." );
3914 if ( $this->trxLevel
&& $this->trxAtomicLevels
) {
3915 // There are still atomic sections open; this cannot be ignored
3916 $levels = $this->flatAtomicSectionList();
3917 throw new DBUnexpectedError(
3919 "$fname: Got COMMIT while atomic sections $levels are still open."
3923 if ( $flush === self
::FLUSHING_INTERNAL ||
$flush === self
::FLUSHING_ALL_PEERS
) {
3924 if ( !$this->trxLevel
) {
3925 return; // nothing to do
3926 } elseif ( !$this->trxAutomatic
) {
3927 throw new DBUnexpectedError(
3929 "$fname: Flushing an explicit transaction, getting out of sync."
3932 } elseif ( !$this->trxLevel
) {
3933 $this->queryLogger
->error(
3934 "$fname: No transaction to commit, something got out of sync." );
3935 return; // nothing to do
3936 } elseif ( $this->trxAutomatic
) {
3937 throw new DBUnexpectedError(
3939 "$fname: Expected mass commit of all peer transactions (DBO_TRX set)."
3943 $this->assertHasConnectionHandle();
3945 $this->runOnTransactionPreCommitCallbacks();
3947 $writeTime = $this->pendingWriteQueryDuration( self
::ESTIMATE_DB_APPLY
);
3948 $this->doCommit( $fname );
3949 $this->trxStatus
= self
::STATUS_TRX_NONE
;
3951 if ( $this->trxDoneWrites
) {
3952 $this->lastWriteTime
= microtime( true );
3953 $this->trxProfiler
->transactionWritingOut(
3955 $this->getDomainID(),
3958 $this->trxWriteAffectedRows
3962 // With FLUSHING_ALL_PEERS, callbacks will be explicitly run later
3963 if ( $flush !== self
::FLUSHING_ALL_PEERS
) {
3964 $this->runOnTransactionIdleCallbacks( self
::TRIGGER_COMMIT
);
3965 $this->runTransactionListenerCallbacks( self
::TRIGGER_COMMIT
);
3970 * Issues the COMMIT command to the database server.
3972 * @see Database::commit()
3973 * @param string $fname
3975 protected function doCommit( $fname ) {
3976 if ( $this->trxLevel
) {
3977 $this->query( 'COMMIT', $fname );
3978 $this->trxLevel
= 0;
3982 final public function rollback( $fname = __METHOD__
, $flush = '' ) {
3983 $trxActive = $this->trxLevel
;
3985 if ( $flush !== self
::FLUSHING_INTERNAL
3986 && $flush !== self
::FLUSHING_ALL_PEERS
3987 && $this->getFlag( self
::DBO_TRX
)
3989 throw new DBUnexpectedError(
3991 "$fname: Expected mass rollback of all peer transactions (DBO_TRX set)."
3996 $this->assertHasConnectionHandle();
3998 $this->doRollback( $fname );
3999 $this->trxStatus
= self
::STATUS_TRX_NONE
;
4000 $this->trxAtomicLevels
= [];
4001 // Estimate the RTT via a query now that trxStatus is OK
4002 $writeTime = $this->pingAndCalculateLastTrxApplyTime();
4004 if ( $this->trxDoneWrites
) {
4005 $this->trxProfiler
->transactionWritingOut(
4007 $this->getDomainID(),
4010 $this->trxWriteAffectedRows
4015 // Clear any commit-dependant callbacks. They might even be present
4016 // only due to transaction rounds, with no SQL transaction being active
4017 $this->trxIdleCallbacks
= [];
4018 $this->trxPreCommitCallbacks
= [];
4020 // With FLUSHING_ALL_PEERS, callbacks will be explicitly run later
4021 if ( $trxActive && $flush !== self
::FLUSHING_ALL_PEERS
) {
4023 $this->runOnTransactionIdleCallbacks( self
::TRIGGER_ROLLBACK
);
4024 } catch ( Exception
$e ) {
4025 // already logged; finish and let LoadBalancer move on during mass-rollback
4028 $this->runTransactionListenerCallbacks( self
::TRIGGER_ROLLBACK
);
4029 } catch ( Exception
$e ) {
4030 // already logged; let LoadBalancer move on during mass-rollback
4033 $this->affectedRowCount
= 0; // for the sake of consistency
4038 * Issues the ROLLBACK command to the database server.
4040 * @see Database::rollback()
4041 * @param string $fname
4043 protected function doRollback( $fname ) {
4044 if ( $this->trxLevel
) {
4045 # Disconnects cause rollback anyway, so ignore those errors
4046 $ignoreErrors = true;
4047 $this->query( 'ROLLBACK', $fname, $ignoreErrors );
4048 $this->trxLevel
= 0;
4052 public function flushSnapshot( $fname = __METHOD__
) {
4053 if ( $this->writesOrCallbacksPending() ||
$this->explicitTrxActive() ) {
4054 // This only flushes transactions to clear snapshots, not to write data
4055 $fnames = implode( ', ', $this->pendingWriteAndCallbackCallers() );
4056 throw new DBUnexpectedError(
4058 "$fname: Cannot flush snapshot because writes are pending ($fnames)."
4062 $this->commit( $fname, self
::FLUSHING_INTERNAL
);
4065 public function explicitTrxActive() {
4066 return $this->trxLevel
&& ( $this->trxAtomicLevels ||
!$this->trxAutomatic
);
4069 public function duplicateTableStructure(
4070 $oldName, $newName, $temporary = false, $fname = __METHOD__
4072 throw new RuntimeException( __METHOD__
. ' is not implemented in descendant class' );
4075 public function listTables( $prefix = null, $fname = __METHOD__
) {
4076 throw new RuntimeException( __METHOD__
. ' is not implemented in descendant class' );
4079 public function listViews( $prefix = null, $fname = __METHOD__
) {
4080 throw new RuntimeException( __METHOD__
. ' is not implemented in descendant class' );
4083 public function timestamp( $ts = 0 ) {
4084 $t = new ConvertibleTimestamp( $ts );
4085 // Let errors bubble up to avoid putting garbage in the DB
4086 return $t->getTimestamp( TS_MW
);
4089 public function timestampOrNull( $ts = null ) {
4090 if ( is_null( $ts ) ) {
4093 return $this->timestamp( $ts );
4097 public function affectedRows() {
4098 return ( $this->affectedRowCount
=== null )
4099 ?
$this->fetchAffectedRowCount() // default to driver value
4100 : $this->affectedRowCount
;
4104 * @return int Number of retrieved rows according to the driver
4106 abstract protected function fetchAffectedRowCount();
4109 * Take the result from a query, and wrap it in a ResultWrapper if
4110 * necessary. Boolean values are passed through as is, to indicate success
4111 * of write queries or failure.
4113 * Once upon a time, Database::query() returned a bare MySQL result
4114 * resource, and it was necessary to call this function to convert it to
4115 * a wrapper. Nowadays, raw database objects are never exposed to external
4116 * callers, so this is unnecessary in external code.
4118 * @param bool|ResultWrapper|resource $result
4119 * @return bool|ResultWrapper
4121 protected function resultObject( $result ) {
4124 } elseif ( $result instanceof ResultWrapper
) {
4126 } elseif ( $result === true ) {
4127 // Successful write query
4130 return new ResultWrapper( $this, $result );
4134 public function ping( &$rtt = null ) {
4135 // Avoid hitting the server if it was hit recently
4136 if ( $this->isOpen() && ( microtime( true ) - $this->lastPing
) < self
::PING_TTL
) {
4137 if ( !func_num_args() ||
$this->rttEstimate
> 0 ) {
4138 $rtt = $this->rttEstimate
;
4139 return true; // don't care about $rtt
4143 // This will reconnect if possible or return false if not
4144 $this->clearFlag( self
::DBO_TRX
, self
::REMEMBER_PRIOR
);
4145 $ok = ( $this->query( self
::PING_QUERY
, __METHOD__
, true ) !== false );
4146 $this->restoreFlags( self
::RESTORE_PRIOR
);
4149 $rtt = $this->rttEstimate
;
4156 * Close any existing (dead) database connection and open a new connection
4158 * @param string $fname
4159 * @return bool True if new connection is opened successfully, false if error
4161 protected function replaceLostConnection( $fname ) {
4162 $this->closeConnection();
4163 $this->opened
= false;
4164 $this->conn
= false;
4166 $this->handleSessionLossPreconnect();
4175 $this->tablePrefix()
4177 $this->lastPing
= microtime( true );
4180 $this->connLogger
->warning(
4181 $fname . ': lost connection to {dbserver}; reconnected',
4183 'dbserver' => $this->getServer(),
4184 'trace' => ( new RuntimeException() )->getTraceAsString()
4187 } catch ( DBConnectionError
$e ) {
4190 $this->connLogger
->error(
4191 $fname . ': lost connection to {dbserver} permanently',
4192 [ 'dbserver' => $this->getServer() ]
4196 $this->handleSessionLossPostconnect();
4201 public function getSessionLagStatus() {
4202 return $this->getRecordedTransactionLagStatus() ?
: $this->getApproximateLagStatus();
4206 * Get the replica DB lag when the current transaction started
4208 * This is useful when transactions might use snapshot isolation
4209 * (e.g. REPEATABLE-READ in innodb), so the "real" lag of that data
4210 * is this lag plus transaction duration. If they don't, it is still
4211 * safe to be pessimistic. This returns null if there is no transaction.
4213 * This returns null if the lag status for this transaction was not yet recorded.
4215 * @return array|null ('lag': seconds or false on error, 'since': UNIX timestamp of BEGIN)
4218 final protected function getRecordedTransactionLagStatus() {
4219 return ( $this->trxLevel
&& $this->trxReplicaLag
!== null )
4220 ?
[ 'lag' => $this->trxReplicaLag
, 'since' => $this->trxTimestamp() ]
4225 * Get a replica DB lag estimate for this server
4227 * @return array ('lag': seconds or false on error, 'since': UNIX timestamp of estimate)
4230 protected function getApproximateLagStatus() {
4232 'lag' => $this->getLBInfo( 'replica' ) ?
$this->getLag() : 0,
4233 'since' => microtime( true )
4238 * Merge the result of getSessionLagStatus() for several DBs
4239 * using the most pessimistic values to estimate the lag of
4240 * any data derived from them in combination
4242 * This is information is useful for caching modules
4244 * @see WANObjectCache::set()
4245 * @see WANObjectCache::getWithSetCallback()
4247 * @param IDatabase $db1
4248 * @param IDatabase|null $db2 [optional]
4249 * @return array Map of values:
4250 * - lag: highest lag of any of the DBs or false on error (e.g. replication stopped)
4251 * - since: oldest UNIX timestamp of any of the DB lag estimates
4252 * - pending: whether any of the DBs have uncommitted changes
4256 public static function getCacheSetOptions( IDatabase
$db1, IDatabase
$db2 = null ) {
4257 $res = [ 'lag' => 0, 'since' => INF
, 'pending' => false ];
4258 foreach ( func_get_args() as $db ) {
4259 /** @var IDatabase $db */
4260 $status = $db->getSessionLagStatus();
4261 if ( $status['lag'] === false ) {
4262 $res['lag'] = false;
4263 } elseif ( $res['lag'] !== false ) {
4264 $res['lag'] = max( $res['lag'], $status['lag'] );
4266 $res['since'] = min( $res['since'], $status['since'] );
4267 $res['pending'] = $res['pending'] ?
: $db->writesPending();
4273 public function getLag() {
4277 public function maxListLen() {
4281 public function encodeBlob( $b ) {
4285 public function decodeBlob( $b ) {
4286 if ( $b instanceof Blob
) {
4292 public function setSessionOptions( array $options ) {
4295 public function sourceFile(
4297 callable
$lineCallback = null,
4298 callable
$resultCallback = null,
4300 callable
$inputCallback = null
4302 Wikimedia\
suppressWarnings();
4303 $fp = fopen( $filename, 'r' );
4304 Wikimedia\restoreWarnings
();
4306 if ( $fp === false ) {
4307 throw new RuntimeException( "Could not open \"{$filename}\".\n" );
4311 $fname = __METHOD__
. "( $filename )";
4315 $error = $this->sourceStream(
4316 $fp, $lineCallback, $resultCallback, $fname, $inputCallback );
4317 } catch ( Exception
$e ) {
4327 public function setSchemaVars( $vars ) {
4328 $this->schemaVars
= $vars;
4331 public function sourceStream(
4333 callable
$lineCallback = null,
4334 callable
$resultCallback = null,
4335 $fname = __METHOD__
,
4336 callable
$inputCallback = null
4338 $delimiterReset = new ScopedCallback(
4339 function ( $delimiter ) {
4340 $this->delimiter
= $delimiter;
4342 [ $this->delimiter
]
4346 while ( !feof( $fp ) ) {
4347 if ( $lineCallback ) {
4348 call_user_func( $lineCallback );
4351 $line = trim( fgets( $fp ) );
4353 if ( $line == '' ) {
4357 if ( $line[0] == '-' && $line[1] == '-' ) {
4365 $done = $this->streamStatementEnd( $cmd, $line );
4369 if ( $done ||
feof( $fp ) ) {
4370 $cmd = $this->replaceVars( $cmd );
4372 if ( $inputCallback ) {
4373 $callbackResult = $inputCallback( $cmd );
4375 if ( is_string( $callbackResult ) ||
!$callbackResult ) {
4376 $cmd = $callbackResult;
4381 $res = $this->query( $cmd, $fname );
4383 if ( $resultCallback ) {
4384 $resultCallback( $res, $this );
4387 if ( $res === false ) {
4388 $err = $this->lastError();
4390 return "Query \"{$cmd}\" failed with error code \"$err\".\n";
4397 ScopedCallback
::consume( $delimiterReset );
4402 * Called by sourceStream() to check if we've reached a statement end
4404 * @param string &$sql SQL assembled so far
4405 * @param string &$newLine New line about to be added to $sql
4406 * @return bool Whether $newLine contains end of the statement
4408 public function streamStatementEnd( &$sql, &$newLine ) {
4409 if ( $this->delimiter
) {
4411 $newLine = preg_replace(
4412 '/' . preg_quote( $this->delimiter
, '/' ) . '$/', '', $newLine );
4413 if ( $newLine != $prev ) {
4422 * Database independent variable replacement. Replaces a set of variables
4423 * in an SQL statement with their contents as given by $this->getSchemaVars().
4425 * Supports '{$var}' `{$var}` and / *$var* / (without the spaces) style variables.
4427 * - '{$var}' should be used for text and is passed through the database's
4429 * - `{$var}` should be used for identifiers (e.g. table and database names).
4430 * It is passed through the database's addIdentifierQuotes method which
4431 * can be overridden if the database uses something other than backticks.
4432 * - / *_* / or / *$wgDBprefix* / passes the name that follows through the
4433 * database's tableName method.
4434 * - / *i* / passes the name that follows through the database's indexName method.
4435 * - In all other cases, / *$var* / is left unencoded. Except for table options,
4436 * its use should be avoided. In 1.24 and older, string encoding was applied.
4438 * @param string $ins SQL statement to replace variables in
4439 * @return string The new SQL statement with variables replaced
4441 protected function replaceVars( $ins ) {
4442 $vars = $this->getSchemaVars();
4443 return preg_replace_callback(
4445 /\* (\$wgDBprefix|[_i]) \*/ (\w*) | # 1-2. tableName, indexName
4446 \'\{\$ (\w+) }\' | # 3. addQuotes
4447 `\{\$ (\w+) }` | # 4. addIdentifierQuotes
4448 /\*\$ (\w+) \*/ # 5. leave unencoded
4450 function ( $m ) use ( $vars ) {
4451 // Note: Because of <https://bugs.php.net/bug.php?id=51881>,
4452 // check for both nonexistent keys *and* the empty string.
4453 if ( isset( $m[1] ) && $m[1] !== '' ) {
4454 if ( $m[1] === 'i' ) {
4455 return $this->indexName( $m[2] );
4457 return $this->tableName( $m[2] );
4459 } elseif ( isset( $m[3] ) && $m[3] !== '' && array_key_exists( $m[3], $vars ) ) {
4460 return $this->addQuotes( $vars[$m[3]] );
4461 } elseif ( isset( $m[4] ) && $m[4] !== '' && array_key_exists( $m[4], $vars ) ) {
4462 return $this->addIdentifierQuotes( $vars[$m[4]] );
4463 } elseif ( isset( $m[5] ) && $m[5] !== '' && array_key_exists( $m[5], $vars ) ) {
4464 return $vars[$m[5]];
4474 * Get schema variables. If none have been set via setSchemaVars(), then
4475 * use some defaults from the current object.
4479 protected function getSchemaVars() {
4480 if ( $this->schemaVars
) {
4481 return $this->schemaVars
;
4483 return $this->getDefaultSchemaVars();
4488 * Get schema variables to use if none have been set via setSchemaVars().
4490 * Override this in derived classes to provide variables for tables.sql
4491 * and SQL patch files.
4495 protected function getDefaultSchemaVars() {
4499 public function lockIsFree( $lockName, $method ) {
4500 // RDBMs methods for checking named locks may or may not count this thread itself.
4501 // In MySQL, IS_FREE_LOCK() returns 0 if the thread already has the lock. This is
4502 // the behavior choosen by the interface for this method.
4503 return !isset( $this->namedLocksHeld
[$lockName] );
4506 public function lock( $lockName, $method, $timeout = 5 ) {
4507 $this->namedLocksHeld
[$lockName] = 1;
4512 public function unlock( $lockName, $method ) {
4513 unset( $this->namedLocksHeld
[$lockName] );
4518 public function getScopedLockAndFlush( $lockKey, $fname, $timeout ) {
4519 if ( $this->writesOrCallbacksPending() ) {
4520 // This only flushes transactions to clear snapshots, not to write data
4521 $fnames = implode( ', ', $this->pendingWriteAndCallbackCallers() );
4522 throw new DBUnexpectedError(
4524 "$fname: Cannot flush pre-lock snapshot because writes are pending ($fnames)."
4528 if ( !$this->lock( $lockKey, $fname, $timeout ) ) {
4532 $unlocker = new ScopedCallback( function () use ( $lockKey, $fname ) {
4533 if ( $this->trxLevel() ) {
4534 // There is a good chance an exception was thrown, causing any early return
4535 // from the caller. Let any error handler get a chance to issue rollback().
4536 // If there isn't one, let the error bubble up and trigger server-side rollback.
4537 $this->onTransactionResolution(
4538 function () use ( $lockKey, $fname ) {
4539 $this->unlock( $lockKey, $fname );
4544 $this->unlock( $lockKey, $fname );
4548 $this->commit( $fname, self
::FLUSHING_INTERNAL
);
4553 public function namedLocksEnqueue() {
4557 public function tableLocksHaveTransactionScope() {
4561 final public function lockTables( array $read, array $write, $method ) {
4562 if ( $this->writesOrCallbacksPending() ) {
4563 throw new DBUnexpectedError( $this, "Transaction writes or callbacks still pending." );
4566 if ( $this->tableLocksHaveTransactionScope() ) {
4567 $this->startAtomic( $method );
4570 return $this->doLockTables( $read, $write, $method );
4574 * Helper function for lockTables() that handles the actual table locking
4576 * @param array $read Array of tables to lock for read access
4577 * @param array $write Array of tables to lock for write access
4578 * @param string $method Name of caller
4581 protected function doLockTables( array $read, array $write, $method ) {
4585 final public function unlockTables( $method ) {
4586 if ( $this->tableLocksHaveTransactionScope() ) {
4587 $this->endAtomic( $method );
4589 return true; // locks released on COMMIT/ROLLBACK
4592 return $this->doUnlockTables( $method );
4596 * Helper function for unlockTables() that handles the actual table unlocking
4598 * @param string $method Name of caller
4601 protected function doUnlockTables( $method ) {
4607 * @param string $tableName
4608 * @param string $fName
4609 * @return bool|ResultWrapper
4612 public function dropTable( $tableName, $fName = __METHOD__
) {
4613 if ( !$this->tableExists( $tableName, $fName ) ) {
4616 $sql = "DROP TABLE " . $this->tableName( $tableName ) . " CASCADE";
4618 return $this->query( $sql, $fName );
4621 public function getInfinity() {
4625 public function encodeExpiry( $expiry ) {
4626 return ( $expiry == '' ||
$expiry == 'infinity' ||
$expiry == $this->getInfinity() )
4627 ?
$this->getInfinity()
4628 : $this->timestamp( $expiry );
4631 public function decodeExpiry( $expiry, $format = TS_MW
) {
4632 if ( $expiry == '' ||
$expiry == 'infinity' ||
$expiry == $this->getInfinity() ) {
4636 return ConvertibleTimestamp
::convert( $format, $expiry );
4639 public function setBigSelects( $value = true ) {
4643 public function isReadOnly() {
4644 return ( $this->getReadOnlyReason() !== false );
4648 * @return string|bool Reason this DB is read-only or false if it is not
4650 protected function getReadOnlyReason() {
4651 $reason = $this->getLBInfo( 'readOnlyReason' );
4653 return is_string( $reason ) ?
$reason : false;
4656 public function setTableAliases( array $aliases ) {
4657 $this->tableAliases
= $aliases;
4660 public function setIndexAliases( array $aliases ) {
4661 $this->indexAliases
= $aliases;
4669 protected function hasFlags( $field, $flags ) {
4670 return ( ( $field & $flags ) === $flags );
4674 * Get the underlying binding connection handle
4676 * Makes sure the connection resource is set (disconnects and ping() failure can unset it).
4677 * This catches broken callers than catch and ignore disconnection exceptions.
4678 * Unlike checking isOpen(), this is safe to call inside of open().
4681 * @throws DBUnexpectedError
4684 protected function getBindingHandle() {
4685 if ( !$this->conn
) {
4686 throw new DBUnexpectedError(
4688 'DB connection was already closed or the connection dropped.'
4699 public function __toString() {
4700 return (string)$this->conn
;
4704 * Make sure that copies do not share the same client binding handle
4705 * @throws DBConnectionError
4707 public function __clone() {
4708 $this->connLogger
->warning(
4709 "Cloning " . static::class . " is not recommended; forking connection:\n" .
4710 ( new RuntimeException() )->getTraceAsString()
4713 if ( $this->isOpen() ) {
4714 // Open a new connection resource without messing with the old one
4715 $this->opened
= false;
4716 $this->conn
= false;
4717 $this->trxEndCallbacks
= []; // don't copy
4718 $this->handleSessionLossPreconnect(); // no trx or locks anymore
4725 $this->tablePrefix()
4727 $this->lastPing
= microtime( true );
4732 * Called by serialize. Throw an exception when DB connection is serialized.
4733 * This causes problems on some database engines because the connection is
4734 * not restored on unserialize.
4736 public function __sleep() {
4737 throw new RuntimeException( 'Database serialization may cause problems, since ' .
4738 'the connection is not restored on wakeup.' );
4742 * Run a few simple sanity checks and close dangling connections
4744 public function __destruct() {
4745 if ( $this->trxLevel
&& $this->trxDoneWrites
) {
4746 trigger_error( "Uncommitted DB writes (transaction from {$this->trxFname})." );
4749 $danglingWriters = $this->pendingWriteAndCallbackCallers();
4750 if ( $danglingWriters ) {
4751 $fnames = implode( ', ', $danglingWriters );
4752 trigger_error( "DB transaction writes or callbacks still pending ($fnames)." );
4755 if ( $this->conn
) {
4756 // Avoid connection leaks for sanity. Normally, resources close at script completion.
4757 // The connection might already be closed in zend/hhvm by now, so suppress warnings.
4758 Wikimedia\
suppressWarnings();
4759 $this->closeConnection();
4760 Wikimedia\restoreWarnings
();
4761 $this->conn
= false;
4762 $this->opened
= false;
4768 * @deprecated since 1.28
4770 class_alias( Database
::class, 'DatabaseBase' );
4773 * @deprecated since 1.29
4775 class_alias( Database
::class, 'Database' );