4 * @defgroup Database Database
6 * This file deals with database interface functions
7 * and query specifics/optimisations.
9 * This program is free software; you can redistribute it and/or modify
10 * it under the terms of the GNU General Public License as published by
11 * the Free Software Foundation; either version 2 of the License, or
12 * (at your option) any later version.
14 * This program is distributed in the hope that it will be useful,
15 * but WITHOUT ANY WARRANTY; without even the implied warranty of
16 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
17 * GNU General Public License for more details.
19 * You should have received a copy of the GNU General Public License along
20 * with this program; if not, write to the Free Software Foundation, Inc.,
21 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
22 * http://www.gnu.org/copyleft/gpl.html
29 * Database abstraction object
32 abstract class DatabaseBase
implements IDatabase
{
33 /** Number of times to re-try an operation in case of deadlock */
34 const DEADLOCK_TRIES
= 4;
35 /** Minimum time to wait before retry, in microseconds */
36 const DEADLOCK_DELAY_MIN
= 500000;
37 /** Maximum time to wait before retry */
38 const DEADLOCK_DELAY_MAX
= 1500000;
40 /** How long before it is worth doing a dummy query to test the connection */
42 const PING_QUERY
= 'SELECT 1 AS ping';
44 const TINY_WRITE_SEC
= .010;
45 const SLOW_WRITE_SEC
= .500;
46 const SMALL_WRITE_ROWS
= 100;
48 /** @var string SQL query */
49 protected $mLastQuery = '';
51 protected $mDoneWrites = false;
52 /** @var string|bool */
53 protected $mPHPError = false;
65 /** @var BagOStuff APC cache */
68 /** @var resource Database connection */
69 protected $mConn = null;
71 protected $mOpened = false;
73 /** @var array[] List of (callable, method name) */
74 protected $mTrxIdleCallbacks = [];
75 /** @var array[] List of (callable, method name) */
76 protected $mTrxPreCommitCallbacks = [];
77 /** @var array[] List of (callable, method name) */
78 protected $mTrxEndCallbacks = [];
79 /** @var array[] Map of (name => (callable, method name)) */
80 protected $mTrxRecurringCallbacks = [];
81 /** @var bool Whether to suppress triggering of transaction end callbacks */
82 protected $mTrxEndCallbacksSuppressed = false;
85 protected $mTablePrefix;
93 protected $mLBInfo = [];
95 protected $mDefaultBigSelects = null;
96 /** @var array|bool */
97 protected $mSchemaVars = false;
99 protected $mSessionVars = [];
100 /** @var array|null */
101 protected $preparedArgs;
102 /** @var string|bool|null Stashed value of html_errors INI setting */
103 protected $htmlErrors;
105 protected $delimiter = ';';
108 * Either 1 if a transaction is active or 0 otherwise.
109 * The other Trx fields may not be meaningfull if this is 0.
113 protected $mTrxLevel = 0;
115 * Either a short hexidecimal string if a transaction is active or ""
118 * @see DatabaseBase::mTrxLevel
120 protected $mTrxShortId = '';
122 * The UNIX time that the transaction started. Callers can assume that if
123 * snapshot isolation is used, then the data is *at least* up to date to that
124 * point (possibly more up-to-date since the first SELECT defines the snapshot).
127 * @see DatabaseBase::mTrxLevel
129 private $mTrxTimestamp = null;
130 /** @var float Lag estimate at the time of BEGIN */
131 private $mTrxReplicaLag = null;
133 * Remembers the function name given for starting the most recent transaction via begin().
134 * Used to provide additional context for error reporting.
137 * @see DatabaseBase::mTrxLevel
139 private $mTrxFname = null;
141 * Record if possible write queries were done in the last transaction started
144 * @see DatabaseBase::mTrxLevel
146 private $mTrxDoneWrites = false;
148 * Record if the current transaction was started implicitly due to DBO_TRX being set.
151 * @see DatabaseBase::mTrxLevel
153 private $mTrxAutomatic = false;
155 * Array of levels of atomicity within transactions
159 private $mTrxAtomicLevels = [];
161 * Record if the current transaction was started implicitly by DatabaseBase::startAtomic
165 private $mTrxAutomaticAtomic = false;
167 * Track the write query callers of the current transaction
171 private $mTrxWriteCallers = [];
173 * @var float Seconds spent in write queries for the current transaction
175 private $mTrxWriteDuration = 0.0;
177 * @var integer Number of write queries for the current transaction
179 private $mTrxWriteQueryCount = 0;
181 * @var float Like mTrxWriteQueryCount but excludes lock-bound, easy to replicate, queries
183 private $mTrxWriteAdjDuration = 0.0;
185 * @var integer Number of write queries counted in mTrxWriteAdjDuration
187 private $mTrxWriteAdjQueryCount = 0;
189 * @var float RTT time estimate
191 private $mRTTEstimate = 0.0;
193 /** @var array Map of (name => 1) for locks obtained via lock() */
194 private $mNamedLocksHeld = [];
196 /** @var IDatabase|null Lazy handle to the master DB this server replicates from */
197 private $lazyMasterHandle;
201 * @var resource File handle for upgrade
203 protected $fileHandle = null;
207 * @var string[] Process cache of VIEWs names in the database
209 protected $allViews = null;
211 /** @var float UNIX timestamp */
212 protected $lastPing = 0.0;
214 /** @var int[] Prior mFlags values */
215 private $priorFlags = [];
219 /** @var TransactionProfiler */
220 protected $trxProfiler;
222 public function getServerInfo() {
223 return $this->getServerVersion();
227 * @return string Command delimiter used by this database engine
229 public function getDelimiter() {
230 return $this->delimiter
;
234 * Boolean, controls output of large amounts of debug information.
235 * @param bool|null $debug
236 * - true to enable debugging
237 * - false to disable debugging
238 * - omitted or null to do nothing
240 * @return bool|null Previous value of the flag
242 public function debug( $debug = null ) {
243 return wfSetBit( $this->mFlags
, DBO_DEBUG
, $debug );
246 public function bufferResults( $buffer = null ) {
247 if ( is_null( $buffer ) ) {
248 return !(bool)( $this->mFlags
& DBO_NOBUFFER
);
250 return !wfSetBit( $this->mFlags
, DBO_NOBUFFER
, !$buffer );
255 * Turns on (false) or off (true) the automatic generation and sending
256 * of a "we're sorry, but there has been a database error" page on
257 * database errors. Default is on (false). When turned off, the
258 * code should use lastErrno() and lastError() to handle the
259 * situation as appropriate.
261 * Do not use this function outside of the Database classes.
263 * @param null|bool $ignoreErrors
264 * @return bool The previous value of the flag.
266 protected function ignoreErrors( $ignoreErrors = null ) {
267 return wfSetBit( $this->mFlags
, DBO_IGNORE
, $ignoreErrors );
270 public function trxLevel() {
271 return $this->mTrxLevel
;
274 public function trxTimestamp() {
275 return $this->mTrxLevel ?
$this->mTrxTimestamp
: null;
278 public function tablePrefix( $prefix = null ) {
279 return wfSetVar( $this->mTablePrefix
, $prefix );
282 public function dbSchema( $schema = null ) {
283 return wfSetVar( $this->mSchema
, $schema );
287 * Set the filehandle to copy write statements to.
289 * @param resource $fh File handle
291 public function setFileHandle( $fh ) {
292 $this->fileHandle
= $fh;
295 public function getLBInfo( $name = null ) {
296 if ( is_null( $name ) ) {
297 return $this->mLBInfo
;
299 if ( array_key_exists( $name, $this->mLBInfo
) ) {
300 return $this->mLBInfo
[$name];
307 public function setLBInfo( $name, $value = null ) {
308 if ( is_null( $value ) ) {
309 $this->mLBInfo
= $name;
311 $this->mLBInfo
[$name] = $value;
316 * Set a lazy-connecting DB handle to the master DB (for replication status purposes)
318 * @param IDatabase $conn
321 public function setLazyMasterHandle( IDatabase
$conn ) {
322 $this->lazyMasterHandle
= $conn;
326 * @return IDatabase|null
327 * @see setLazyMasterHandle()
330 public function getLazyMasterHandle() {
331 return $this->lazyMasterHandle
;
335 * @return TransactionProfiler
337 protected function getTransactionProfiler() {
338 return $this->trxProfiler
;
342 * @param TransactionProfiler $profiler
345 public function setTransactionProfiler( TransactionProfiler
$profiler ) {
346 $this->trxProfiler
= $profiler;
350 * Returns true if this database supports (and uses) cascading deletes
354 public function cascadingDeletes() {
359 * Returns true if this database supports (and uses) triggers (e.g. on the page table)
363 public function cleanupTriggers() {
368 * Returns true if this database is strict about what can be put into an IP field.
369 * Specifically, it uses a NULL value instead of an empty string.
373 public function strictIPs() {
378 * Returns true if this database uses timestamps rather than integers
382 public function realTimestamps() {
386 public function implicitGroupby() {
390 public function implicitOrderby() {
395 * Returns true if this database can do a native search on IP columns
396 * e.g. this works as expected: .. WHERE rc_ip = '127.42.12.102/32';
400 public function searchableIPs() {
405 * Returns true if this database can use functional indexes
409 public function functionalIndexes() {
413 public function lastQuery() {
414 return $this->mLastQuery
;
417 public function doneWrites() {
418 return (bool)$this->mDoneWrites
;
421 public function lastDoneWrites() {
422 return $this->mDoneWrites ?
: false;
425 public function writesPending() {
426 return $this->mTrxLevel
&& $this->mTrxDoneWrites
;
429 public function writesOrCallbacksPending() {
430 return $this->mTrxLevel
&& (
431 $this->mTrxDoneWrites ||
$this->mTrxIdleCallbacks ||
$this->mTrxPreCommitCallbacks
435 public function pendingWriteQueryDuration( $type = self
::ESTIMATE_TOTAL
) {
436 if ( !$this->mTrxLevel
) {
438 } elseif ( !$this->mTrxDoneWrites
) {
443 case self
::ESTIMATE_DB_APPLY
:
445 $rttAdjTotal = $this->mTrxWriteAdjQueryCount
* $rtt;
446 $applyTime = max( $this->mTrxWriteAdjDuration
- $rttAdjTotal, 0 );
447 // For omitted queries, make them count as something at least
448 $omitted = $this->mTrxWriteQueryCount
- $this->mTrxWriteAdjQueryCount
;
449 $applyTime +
= self
::TINY_WRITE_SEC
* $omitted;
452 default: // everything
453 return $this->mTrxWriteDuration
;
457 public function pendingWriteCallers() {
458 return $this->mTrxLevel ?
$this->mTrxWriteCallers
: [];
461 public function isOpen() {
462 return $this->mOpened
;
465 public function setFlag( $flag, $remember = self
::REMEMBER_NOTHING
) {
466 if ( $remember === self
::REMEMBER_PRIOR
) {
467 array_push( $this->priorFlags
, $this->mFlags
);
469 $this->mFlags |
= $flag;
472 public function clearFlag( $flag, $remember = self
::REMEMBER_NOTHING
) {
473 if ( $remember === self
::REMEMBER_PRIOR
) {
474 array_push( $this->priorFlags
, $this->mFlags
);
476 $this->mFlags
&= ~
$flag;
479 public function restoreFlags( $state = self
::RESTORE_PRIOR
) {
480 if ( !$this->priorFlags
) {
484 if ( $state === self
::RESTORE_INITIAL
) {
485 $this->mFlags
= reset( $this->priorFlags
);
486 $this->priorFlags
= [];
488 $this->mFlags
= array_pop( $this->priorFlags
);
492 public function getFlag( $flag ) {
493 return !!( $this->mFlags
& $flag );
496 public function getProperty( $name ) {
500 public function getWikiID() {
501 if ( $this->mTablePrefix
) {
502 return "{$this->mDBname}-{$this->mTablePrefix}";
504 return $this->mDBname
;
509 * Return a path to the DBMS-specific SQL file if it exists,
510 * otherwise default SQL file
512 * @param string $filename
515 private function getSqlFilePath( $filename ) {
517 $dbmsSpecificFilePath = "$IP/maintenance/" . $this->getType() . "/$filename";
518 if ( file_exists( $dbmsSpecificFilePath ) ) {
519 return $dbmsSpecificFilePath;
521 return "$IP/maintenance/$filename";
526 * Return a path to the DBMS-specific schema file,
527 * otherwise default to tables.sql
531 public function getSchemaPath() {
532 return $this->getSqlFilePath( 'tables.sql' );
536 * Return a path to the DBMS-specific update key file,
537 * otherwise default to update-keys.sql
541 public function getUpdateKeysPath() {
542 return $this->getSqlFilePath( 'update-keys.sql' );
546 * Get information about an index into an object
547 * @param string $table Table name
548 * @param string $index Index name
549 * @param string $fname Calling function name
550 * @return mixed Database-specific index description class or false if the index does not exist
552 abstract function indexInfo( $table, $index, $fname = __METHOD__
);
555 * Wrapper for addslashes()
557 * @param string $s String to be slashed.
558 * @return string Slashed string.
560 abstract function strencode( $s );
565 * FIXME: It is possible to construct a Database object with no associated
566 * connection object, by specifying no parameters to __construct(). This
567 * feature is deprecated and should be removed.
569 * DatabaseBase subclasses should not be constructed directly in external
570 * code. DatabaseBase::factory() should be used instead.
572 * @param array $params Parameters passed from DatabaseBase::factory()
574 function __construct( array $params ) {
575 global $wgDBprefix, $wgDBmwschema;
577 $this->srvCache
= ObjectCache
::getLocalServerInstance( 'hash' );
579 $server = $params['host'];
580 $user = $params['user'];
581 $password = $params['password'];
582 $dbName = $params['dbname'];
583 $flags = $params['flags'];
584 $tablePrefix = $params['tablePrefix'];
585 $schema = $params['schema'];
586 $foreign = $params['foreign'];
588 $this->cliMode
= isset( $params['cliMode'] )
590 : ( PHP_SAPI
=== 'cli' );
592 $this->mFlags
= $flags;
593 if ( $this->mFlags
& DBO_DEFAULT
) {
594 if ( $this->cliMode
) {
595 $this->mFlags
&= ~DBO_TRX
;
597 $this->mFlags |
= DBO_TRX
;
601 $this->mSessionVars
= $params['variables'];
603 /** Get the default table prefix*/
604 if ( $tablePrefix === 'get from global' ) {
605 $this->mTablePrefix
= $wgDBprefix;
607 $this->mTablePrefix
= $tablePrefix;
610 /** Get the database schema*/
611 if ( $schema === 'get from global' ) {
612 $this->mSchema
= $wgDBmwschema;
614 $this->mSchema
= $schema;
617 $this->mForeign
= $foreign;
619 $this->profiler
= isset( $params['profiler'] )
620 ?
$params['profiler']
621 : Profiler
::instance(); // @TODO: remove global state
622 $this->trxProfiler
= isset( $params['trxProfiler'] )
623 ?
$params['trxProfiler']
624 : new TransactionProfiler();
627 $this->open( $server, $user, $password, $dbName );
633 * Called by serialize. Throw an exception when DB connection is serialized.
634 * This causes problems on some database engines because the connection is
635 * not restored on unserialize.
637 public function __sleep() {
638 throw new MWException( 'Database serialization may cause problems, since ' .
639 'the connection is not restored on wakeup.' );
643 * Given a DB type, construct the name of the appropriate child class of
644 * DatabaseBase. This is designed to replace all of the manual stuff like:
645 * $class = 'Database' . ucfirst( strtolower( $dbType ) );
646 * as well as validate against the canonical list of DB types we have
648 * This factory function is mostly useful for when you need to connect to a
649 * database other than the MediaWiki default (such as for external auth,
650 * an extension, et cetera). Do not use this to connect to the MediaWiki
651 * database. Example uses in core:
652 * @see LoadBalancer::reallyOpenConnection()
653 * @see ForeignDBRepo::getMasterDB()
654 * @see WebInstallerDBConnect::execute()
658 * @param string $dbType A possible DB type
659 * @param array $p An array of options to pass to the constructor.
660 * Valid options are: host, user, password, dbname, flags, tablePrefix, schema, driver
661 * @throws MWException If the database driver or extension cannot be found
662 * @return DatabaseBase|null DatabaseBase subclass or null
664 final public static function factory( $dbType, $p = [] ) {
665 global $wgCommandLineMode;
667 $canonicalDBTypes = [
668 'mysql' => [ 'mysqli', 'mysql' ],
676 $dbType = strtolower( $dbType );
677 if ( isset( $canonicalDBTypes[$dbType] ) && $canonicalDBTypes[$dbType] ) {
678 $possibleDrivers = $canonicalDBTypes[$dbType];
679 if ( !empty( $p['driver'] ) ) {
680 if ( in_array( $p['driver'], $possibleDrivers ) ) {
681 $driver = $p['driver'];
683 throw new MWException( __METHOD__
.
684 " cannot construct Database with type '$dbType' and driver '{$p['driver']}'" );
687 foreach ( $possibleDrivers as $posDriver ) {
688 if ( extension_loaded( $posDriver ) ) {
689 $driver = $posDriver;
697 if ( $driver === false ) {
698 throw new MWException( __METHOD__
.
699 " no viable database extension found for type '$dbType'" );
702 // Determine schema defaults. Currently Microsoft SQL Server uses $wgDBmwschema,
703 // and everything else doesn't use a schema (e.g. null)
704 // Although postgres and oracle support schemas, we don't use them (yet)
705 // to maintain backwards compatibility
707 'mssql' => 'get from global',
710 $class = 'Database' . ucfirst( $driver );
711 if ( class_exists( $class ) && is_subclass_of( $class, 'DatabaseBase' ) ) {
712 // Resolve some defaults for b/c
713 $p['host'] = isset( $p['host'] ) ?
$p['host'] : false;
714 $p['user'] = isset( $p['user'] ) ?
$p['user'] : false;
715 $p['password'] = isset( $p['password'] ) ?
$p['password'] : false;
716 $p['dbname'] = isset( $p['dbname'] ) ?
$p['dbname'] : false;
717 $p['flags'] = isset( $p['flags'] ) ?
$p['flags'] : 0;
718 $p['variables'] = isset( $p['variables'] ) ?
$p['variables'] : [];
719 $p['tablePrefix'] = isset( $p['tablePrefix'] ) ?
$p['tablePrefix'] : 'get from global';
720 if ( !isset( $p['schema'] ) ) {
721 $p['schema'] = isset( $defaultSchemas[$dbType] ) ?
$defaultSchemas[$dbType] : null;
723 $p['foreign'] = isset( $p['foreign'] ) ?
$p['foreign'] : false;
724 $p['cliMode'] = $wgCommandLineMode;
726 return new $class( $p );
732 protected function installErrorHandler() {
733 $this->mPHPError
= false;
734 $this->htmlErrors
= ini_set( 'html_errors', '0' );
735 set_error_handler( [ $this, 'connectionErrorHandler' ] );
739 * @return bool|string
741 protected function restoreErrorHandler() {
742 restore_error_handler();
743 if ( $this->htmlErrors
!== false ) {
744 ini_set( 'html_errors', $this->htmlErrors
);
746 if ( $this->mPHPError
) {
747 $error = preg_replace( '!\[<a.*</a>\]!', '', $this->mPHPError
);
748 $error = preg_replace( '!^.*?:\s?(.*)$!', '$1', $error );
758 * @param string $errstr
760 public function connectionErrorHandler( $errno, $errstr ) {
761 $this->mPHPError
= $errstr;
765 * Create a log context to pass to wfLogDBError or other logging functions.
767 * @param array $extras Additional data to add to context
770 protected function getLogContext( array $extras = [] ) {
773 'db_server' => $this->mServer
,
774 'db_name' => $this->mDBname
,
775 'db_user' => $this->mUser
,
781 public function close() {
782 if ( $this->mConn
) {
783 if ( $this->trxLevel() ) {
784 if ( !$this->mTrxAutomatic
) {
785 wfWarn( "Transaction still in progress (from {$this->mTrxFname}), " .
786 " performing implicit commit before closing connection!" );
789 $this->commit( __METHOD__
, self
::FLUSHING_INTERNAL
);
792 $closed = $this->closeConnection();
793 $this->mConn
= false;
794 } elseif ( $this->mTrxIdleCallbacks ||
$this->mTrxEndCallbacks
) { // sanity
795 throw new MWException( "Transaction callbacks still pending." );
799 $this->mOpened
= false;
805 * Make sure isOpen() returns true as a sanity check
807 * @throws DBUnexpectedError
809 protected function assertOpen() {
810 if ( !$this->isOpen() ) {
811 throw new DBUnexpectedError( $this, "DB connection was already closed." );
816 * Closes underlying database connection
818 * @return bool Whether connection was closed successfully
820 abstract protected function closeConnection();
822 function reportConnectionError( $error = 'Unknown error' ) {
823 $myError = $this->lastError();
829 throw new DBConnectionError( $this, $error );
833 * The DBMS-dependent part of query()
835 * @param string $sql SQL query.
836 * @return ResultWrapper|bool Result object to feed to fetchObject,
837 * fetchRow, ...; or false on failure
839 abstract protected function doQuery( $sql );
842 * Determine whether a query writes to the DB.
843 * Should return true if unsure.
848 protected function isWriteQuery( $sql ) {
850 '/^(?:SELECT|BEGIN|ROLLBACK|COMMIT|SET|SHOW|EXPLAIN|\(SELECT)\b/i', $sql );
855 * @return string|null
857 protected function getQueryVerb( $sql ) {
858 return preg_match( '/^\s*([a-z]+)/i', $sql, $m ) ?
strtoupper( $m[1] ) : null;
862 * Determine whether a SQL statement is sensitive to isolation level.
863 * A SQL statement is considered transactable if its result could vary
864 * depending on the transaction isolation level. Operational commands
865 * such as 'SET' and 'SHOW' are not considered to be transactable.
870 protected function isTransactableQuery( $sql ) {
871 $verb = $this->getQueryVerb( $sql );
872 return !in_array( $verb, [ 'BEGIN', 'COMMIT', 'ROLLBACK', 'SHOW', 'SET' ], true );
875 public function query( $sql, $fname = __METHOD__
, $tempIgnore = false ) {
878 $priorWritesPending = $this->writesOrCallbacksPending();
879 $this->mLastQuery
= $sql;
881 $isWrite = $this->isWriteQuery( $sql );
883 $reason = $this->getReadOnlyReason();
884 if ( $reason !== false ) {
885 throw new DBReadOnlyError( $this, "Database is read-only: $reason" );
887 # Set a flag indicating that writes have been done
888 $this->mDoneWrites
= microtime( true );
891 # Add a comment for easy SHOW PROCESSLIST interpretation
892 if ( is_object( $wgUser ) && $wgUser->isItemLoaded( 'name' ) ) {
893 $userName = $wgUser->getName();
894 if ( mb_strlen( $userName ) > 15 ) {
895 $userName = mb_substr( $userName, 0, 15 ) . '...';
897 $userName = str_replace( '/', '', $userName );
902 // Add trace comment to the begin of the sql string, right after the operator.
903 // Or, for one-word queries (like "BEGIN" or COMMIT") add it to the end (bug 42598)
904 $commentedSql = preg_replace( '/\s|$/', " /* $fname $userName */ ", $sql, 1 );
906 # Start implicit transactions that wrap the request if DBO_TRX is enabled
907 if ( !$this->mTrxLevel
&& $this->getFlag( DBO_TRX
)
908 && $this->isTransactableQuery( $sql )
910 $this->begin( __METHOD__
. " ($fname)", self
::TRANSACTION_INTERNAL
);
911 $this->mTrxAutomatic
= true;
914 # Keep track of whether the transaction has write queries pending
915 if ( $this->mTrxLevel
&& !$this->mTrxDoneWrites
&& $isWrite ) {
916 $this->mTrxDoneWrites
= true;
917 $this->getTransactionProfiler()->transactionWritingIn(
918 $this->mServer
, $this->mDBname
, $this->mTrxShortId
);
921 if ( $this->debug() ) {
922 wfDebugLog( 'queries', sprintf( "%s: %s", $this->mDBname
, $commentedSql ) );
925 # Avoid fatals if close() was called
928 # Send the query to the server
929 $ret = $this->doProfiledQuery( $sql, $commentedSql, $isWrite, $fname );
931 # Try reconnecting if the connection was lost
932 if ( false === $ret && $this->wasErrorReissuable() ) {
933 $recoverable = $this->canRecoverFromDisconnect( $sql, $priorWritesPending );
934 # Stash the last error values before anything might clear them
935 $lastError = $this->lastError();
936 $lastErrno = $this->lastErrno();
937 # Update state tracking to reflect transaction loss due to disconnection
938 $this->handleTransactionLoss();
939 wfDebug( "Connection lost, reconnecting...\n" );
940 if ( $this->reconnect() ) {
941 wfDebug( "Reconnected\n" );
942 $msg = __METHOD__
. ": lost connection to {$this->getServer()}; reconnected";
943 wfDebugLog( 'DBPerformance', "$msg:\n" . wfBacktrace( true ) );
945 if ( !$recoverable ) {
946 # Callers may catch the exception and continue to use the DB
947 $this->reportQueryError( $lastError, $lastErrno, $sql, $fname );
949 # Should be safe to silently retry the query
950 $ret = $this->doProfiledQuery( $sql, $commentedSql, $isWrite, $fname );
953 wfDebug( "Failed\n" );
957 if ( false === $ret ) {
958 # Deadlocks cause the entire transaction to abort, not just the statement.
959 # http://dev.mysql.com/doc/refman/5.7/en/innodb-error-handling.html
960 # https://www.postgresql.org/docs/9.1/static/explicit-locking.html
961 if ( $this->wasDeadlock() ) {
962 if ( $this->explicitTrxActive() ||
$priorWritesPending ) {
963 $tempIgnore = false; // not recoverable
965 # Update state tracking to reflect transaction loss
966 $this->handleTransactionLoss();
969 $this->reportQueryError(
970 $this->lastError(), $this->lastErrno(), $sql, $fname, $tempIgnore );
973 $res = $this->resultObject( $ret );
978 private function doProfiledQuery( $sql, $commentedSql, $isWrite, $fname ) {
979 $isMaster = !is_null( $this->getLBInfo( 'master' ) );
980 # generalizeSQL() will probably cut down the query to reasonable
981 # logging size most of the time. The substr is really just a sanity check.
983 $queryProf = 'query-m: ' . substr( DatabaseBase
::generalizeSQL( $sql ), 0, 255 );
985 $queryProf = 'query: ' . substr( DatabaseBase
::generalizeSQL( $sql ), 0, 255 );
988 # Include query transaction state
989 $queryProf .= $this->mTrxShortId ?
" [TRX#{$this->mTrxShortId}]" : "";
991 $startTime = microtime( true );
992 $this->profiler
->profileIn( $queryProf );
993 $ret = $this->doQuery( $commentedSql );
994 $this->profiler
->profileOut( $queryProf );
995 $queryRuntime = max( microtime( true ) - $startTime, 0.0 );
997 unset( $queryProfSection ); // profile out (if set)
999 if ( $ret !== false ) {
1000 $this->lastPing
= $startTime;
1001 if ( $isWrite && $this->mTrxLevel
) {
1002 $this->updateTrxWriteQueryTime( $sql, $queryRuntime );
1003 $this->mTrxWriteCallers
[] = $fname;
1007 if ( $sql === self
::PING_QUERY
) {
1008 $this->mRTTEstimate
= $queryRuntime;
1011 $this->getTransactionProfiler()->recordQueryCompletion(
1012 $queryProf, $startTime, $isWrite, $this->affectedRows()
1014 MWDebug
::query( $sql, $fname, $isMaster, $queryRuntime );
1020 * Update the estimated run-time of a query, not counting large row lock times
1022 * LoadBalancer can be set to rollback transactions that will create huge replication
1023 * lag. It bases this estimate off of pendingWriteQueryDuration(). Certain simple
1024 * queries, like inserting a row can take a long time due to row locking. This method
1025 * uses some simple heuristics to discount those cases.
1027 * @param string $sql A SQL write query
1028 * @param float $runtime Total runtime, including RTT
1030 private function updateTrxWriteQueryTime( $sql, $runtime ) {
1031 // Whether this is indicative of replica DB runtime (except for RBR or ws_repl)
1032 $indicativeOfReplicaRuntime = true;
1033 if ( $runtime > self
::SLOW_WRITE_SEC
) {
1034 $verb = $this->getQueryVerb( $sql );
1035 // insert(), upsert(), replace() are fast unless bulky in size or blocked on locks
1036 if ( $verb === 'INSERT' ) {
1037 $indicativeOfReplicaRuntime = $this->affectedRows() > self
::SMALL_WRITE_ROWS
;
1038 } elseif ( $verb === 'REPLACE' ) {
1039 $indicativeOfReplicaRuntime = $this->affectedRows() > self
::SMALL_WRITE_ROWS
/ 2;
1043 $this->mTrxWriteDuration +
= $runtime;
1044 $this->mTrxWriteQueryCount +
= 1;
1045 if ( $indicativeOfReplicaRuntime ) {
1046 $this->mTrxWriteAdjDuration +
= $runtime;
1047 $this->mTrxWriteAdjQueryCount +
= 1;
1051 private function canRecoverFromDisconnect( $sql, $priorWritesPending ) {
1052 # Transaction dropped; this can mean lost writes, or REPEATABLE-READ snapshots.
1053 # Dropped connections also mean that named locks are automatically released.
1054 # Only allow error suppression in autocommit mode or when the lost transaction
1055 # didn't matter anyway (aside from DBO_TRX snapshot loss).
1056 if ( $this->mNamedLocksHeld
) {
1057 return false; // possible critical section violation
1058 } elseif ( $sql === 'COMMIT' ) {
1059 return !$priorWritesPending; // nothing written anyway? (T127428)
1060 } elseif ( $sql === 'ROLLBACK' ) {
1061 return true; // transaction lost...which is also what was requested :)
1062 } elseif ( $this->explicitTrxActive() ) {
1063 return false; // don't drop atomocity
1064 } elseif ( $priorWritesPending ) {
1065 return false; // prior writes lost from implicit transaction
1071 private function handleTransactionLoss() {
1072 $this->mTrxLevel
= 0;
1073 $this->mTrxIdleCallbacks
= []; // bug 65263
1074 $this->mTrxPreCommitCallbacks
= []; // bug 65263
1076 // Handle callbacks in mTrxEndCallbacks
1077 $this->runOnTransactionIdleCallbacks( self
::TRIGGER_ROLLBACK
);
1078 $this->runTransactionListenerCallbacks( self
::TRIGGER_ROLLBACK
);
1080 } catch ( Exception
$e ) {
1081 // Already logged; move on...
1086 public function reportQueryError( $error, $errno, $sql, $fname, $tempIgnore = false ) {
1087 if ( $this->ignoreErrors() ||
$tempIgnore ) {
1088 wfDebug( "SQL ERROR (ignored): $error\n" );
1090 $sql1line = mb_substr( str_replace( "\n", "\\n", $sql ), 0, 5 * 1024 );
1092 "{fname}\t{db_server}\t{errno}\t{error}\t{sql1line}",
1093 $this->getLogContext( [
1094 'method' => __METHOD__
,
1097 'sql1line' => $sql1line,
1101 wfDebug( "SQL ERROR: " . $error . "\n" );
1102 throw new DBQueryError( $this, $error, $errno, $sql, $fname );
1107 * Intended to be compatible with the PEAR::DB wrapper functions.
1108 * http://pear.php.net/manual/en/package.database.db.intro-execute.php
1110 * ? = scalar value, quoted as necessary
1111 * ! = raw SQL bit (a function for instance)
1112 * & = filename; reads the file and inserts as a blob
1113 * (we don't use this though...)
1115 * @param string $sql
1116 * @param string $func
1120 protected function prepare( $sql, $func = 'DatabaseBase::prepare' ) {
1121 /* MySQL doesn't support prepared statements (yet), so just
1122 * pack up the query for reference. We'll manually replace
1125 return [ 'query' => $sql, 'func' => $func ];
1129 * Free a prepared query, generated by prepare().
1130 * @param string $prepared
1132 protected function freePrepared( $prepared ) {
1133 /* No-op by default */
1137 * Execute a prepared query with the various arguments
1138 * @param string $prepared The prepared sql
1139 * @param mixed $args Either an array here, or put scalars as varargs
1141 * @return ResultWrapper
1143 public function execute( $prepared, $args = null ) {
1144 if ( !is_array( $args ) ) {
1146 $args = func_get_args();
1147 array_shift( $args );
1150 $sql = $this->fillPrepared( $prepared['query'], $args );
1152 return $this->query( $sql, $prepared['func'] );
1156 * For faking prepared SQL statements on DBs that don't support it directly.
1158 * @param string $preparedQuery A 'preparable' SQL statement
1159 * @param array $args Array of Arguments to fill it with
1160 * @return string Executable SQL
1162 public function fillPrepared( $preparedQuery, $args ) {
1164 $this->preparedArgs
=& $args;
1166 return preg_replace_callback( '/(\\\\[?!&]|[?!&])/',
1167 [ &$this, 'fillPreparedArg' ], $preparedQuery );
1171 * preg_callback func for fillPrepared()
1172 * The arguments should be in $this->preparedArgs and must not be touched
1173 * while we're doing this.
1175 * @param array $matches
1176 * @throws DBUnexpectedError
1179 protected function fillPreparedArg( $matches ) {
1180 switch ( $matches[1] ) {
1189 list( /* $n */, $arg ) = each( $this->preparedArgs
);
1191 switch ( $matches[1] ) {
1193 return $this->addQuotes( $arg );
1197 # return $this->addQuotes( file_get_contents( $arg ) );
1198 throw new DBUnexpectedError(
1200 '& mode is not implemented. If it\'s really needed, uncomment the line above.'
1203 throw new DBUnexpectedError(
1205 'Received invalid match. This should never happen!'
1210 public function freeResult( $res ) {
1213 public function selectField(
1214 $table, $var, $cond = '', $fname = __METHOD__
, $options = []
1216 if ( $var === '*' ) { // sanity
1217 throw new DBUnexpectedError( $this, "Cannot use a * field: got '$var'" );
1220 if ( !is_array( $options ) ) {
1221 $options = [ $options ];
1224 $options['LIMIT'] = 1;
1226 $res = $this->select( $table, $var, $cond, $fname, $options );
1227 if ( $res === false ||
!$this->numRows( $res ) ) {
1231 $row = $this->fetchRow( $res );
1233 if ( $row !== false ) {
1234 return reset( $row );
1240 public function selectFieldValues(
1241 $table, $var, $cond = '', $fname = __METHOD__
, $options = [], $join_conds = []
1243 if ( $var === '*' ) { // sanity
1244 throw new DBUnexpectedError( $this, "Cannot use a * field" );
1245 } elseif ( !is_string( $var ) ) { // sanity
1246 throw new DBUnexpectedError( $this, "Cannot use an array of fields" );
1249 if ( !is_array( $options ) ) {
1250 $options = [ $options ];
1253 $res = $this->select( $table, $var, $cond, $fname, $options, $join_conds );
1254 if ( $res === false ) {
1259 foreach ( $res as $row ) {
1260 $values[] = $row->$var;
1267 * Returns an optional USE INDEX clause to go after the table, and a
1268 * string to go at the end of the query.
1270 * @param array $options Associative array of options to be turned into
1271 * an SQL query, valid keys are listed in the function.
1273 * @see DatabaseBase::select()
1275 public function makeSelectOptions( $options ) {
1276 $preLimitTail = $postLimitTail = '';
1281 foreach ( $options as $key => $option ) {
1282 if ( is_numeric( $key ) ) {
1283 $noKeyOptions[$option] = true;
1287 $preLimitTail .= $this->makeGroupByWithHaving( $options );
1289 $preLimitTail .= $this->makeOrderBy( $options );
1291 // if (isset($options['LIMIT'])) {
1292 // $tailOpts .= $this->limitResult('', $options['LIMIT'],
1293 // isset($options['OFFSET']) ? $options['OFFSET']
1297 if ( isset( $noKeyOptions['FOR UPDATE'] ) ) {
1298 $postLimitTail .= ' FOR UPDATE';
1301 if ( isset( $noKeyOptions['LOCK IN SHARE MODE'] ) ) {
1302 $postLimitTail .= ' LOCK IN SHARE MODE';
1305 if ( isset( $noKeyOptions['DISTINCT'] ) ||
isset( $noKeyOptions['DISTINCTROW'] ) ) {
1306 $startOpts .= 'DISTINCT';
1309 # Various MySQL extensions
1310 if ( isset( $noKeyOptions['STRAIGHT_JOIN'] ) ) {
1311 $startOpts .= ' /*! STRAIGHT_JOIN */';
1314 if ( isset( $noKeyOptions['HIGH_PRIORITY'] ) ) {
1315 $startOpts .= ' HIGH_PRIORITY';
1318 if ( isset( $noKeyOptions['SQL_BIG_RESULT'] ) ) {
1319 $startOpts .= ' SQL_BIG_RESULT';
1322 if ( isset( $noKeyOptions['SQL_BUFFER_RESULT'] ) ) {
1323 $startOpts .= ' SQL_BUFFER_RESULT';
1326 if ( isset( $noKeyOptions['SQL_SMALL_RESULT'] ) ) {
1327 $startOpts .= ' SQL_SMALL_RESULT';
1330 if ( isset( $noKeyOptions['SQL_CALC_FOUND_ROWS'] ) ) {
1331 $startOpts .= ' SQL_CALC_FOUND_ROWS';
1334 if ( isset( $noKeyOptions['SQL_CACHE'] ) ) {
1335 $startOpts .= ' SQL_CACHE';
1338 if ( isset( $noKeyOptions['SQL_NO_CACHE'] ) ) {
1339 $startOpts .= ' SQL_NO_CACHE';
1342 if ( isset( $options['USE INDEX'] ) && is_string( $options['USE INDEX'] ) ) {
1343 $useIndex = $this->useIndexClause( $options['USE INDEX'] );
1347 if ( isset( $options['IGNORE INDEX'] ) && is_string( $options['IGNORE INDEX'] ) ) {
1348 $ignoreIndex = $this->ignoreIndexClause( $options['IGNORE INDEX'] );
1353 return [ $startOpts, $useIndex, $preLimitTail, $postLimitTail, $ignoreIndex ];
1357 * Returns an optional GROUP BY with an optional HAVING
1359 * @param array $options Associative array of options
1361 * @see DatabaseBase::select()
1364 public function makeGroupByWithHaving( $options ) {
1366 if ( isset( $options['GROUP BY'] ) ) {
1367 $gb = is_array( $options['GROUP BY'] )
1368 ?
implode( ',', $options['GROUP BY'] )
1369 : $options['GROUP BY'];
1370 $sql .= ' GROUP BY ' . $gb;
1372 if ( isset( $options['HAVING'] ) ) {
1373 $having = is_array( $options['HAVING'] )
1374 ?
$this->makeList( $options['HAVING'], LIST_AND
)
1375 : $options['HAVING'];
1376 $sql .= ' HAVING ' . $having;
1383 * Returns an optional ORDER BY
1385 * @param array $options Associative array of options
1387 * @see DatabaseBase::select()
1390 public function makeOrderBy( $options ) {
1391 if ( isset( $options['ORDER BY'] ) ) {
1392 $ob = is_array( $options['ORDER BY'] )
1393 ?
implode( ',', $options['ORDER BY'] )
1394 : $options['ORDER BY'];
1396 return ' ORDER BY ' . $ob;
1402 // See IDatabase::select for the docs for this function
1403 public function select( $table, $vars, $conds = '', $fname = __METHOD__
,
1404 $options = [], $join_conds = [] ) {
1405 $sql = $this->selectSQLText( $table, $vars, $conds, $fname, $options, $join_conds );
1407 return $this->query( $sql, $fname );
1410 public function selectSQLText( $table, $vars, $conds = '', $fname = __METHOD__
,
1411 $options = [], $join_conds = []
1413 if ( is_array( $vars ) ) {
1414 $vars = implode( ',', $this->fieldNamesWithAlias( $vars ) );
1417 $options = (array)$options;
1418 $useIndexes = ( isset( $options['USE INDEX'] ) && is_array( $options['USE INDEX'] ) )
1419 ?
$options['USE INDEX']
1421 $ignoreIndexes = ( isset( $options['IGNORE INDEX'] ) && is_array( $options['IGNORE INDEX'] ) )
1422 ?
$options['IGNORE INDEX']
1425 if ( is_array( $table ) ) {
1427 $this->tableNamesWithIndexClauseOrJOIN( $table, $useIndexes, $ignoreIndexes, $join_conds );
1428 } elseif ( $table != '' ) {
1429 if ( $table[0] == ' ' ) {
1430 $from = ' FROM ' . $table;
1433 $this->tableNamesWithIndexClauseOrJOIN( [ $table ], $useIndexes, $ignoreIndexes, [] );
1439 list( $startOpts, $useIndex, $preLimitTail, $postLimitTail, $ignoreIndex ) =
1440 $this->makeSelectOptions( $options );
1442 if ( !empty( $conds ) ) {
1443 if ( is_array( $conds ) ) {
1444 $conds = $this->makeList( $conds, LIST_AND
);
1446 $sql = "SELECT $startOpts $vars $from $useIndex $ignoreIndex WHERE $conds $preLimitTail";
1448 $sql = "SELECT $startOpts $vars $from $useIndex $ignoreIndex $preLimitTail";
1451 if ( isset( $options['LIMIT'] ) ) {
1452 $sql = $this->limitResult( $sql, $options['LIMIT'],
1453 isset( $options['OFFSET'] ) ?
$options['OFFSET'] : false );
1455 $sql = "$sql $postLimitTail";
1457 if ( isset( $options['EXPLAIN'] ) ) {
1458 $sql = 'EXPLAIN ' . $sql;
1464 public function selectRow( $table, $vars, $conds, $fname = __METHOD__
,
1465 $options = [], $join_conds = []
1467 $options = (array)$options;
1468 $options['LIMIT'] = 1;
1469 $res = $this->select( $table, $vars, $conds, $fname, $options, $join_conds );
1471 if ( $res === false ) {
1475 if ( !$this->numRows( $res ) ) {
1479 $obj = $this->fetchObject( $res );
1484 public function estimateRowCount(
1485 $table, $vars = '*', $conds = '', $fname = __METHOD__
, $options = []
1488 $res = $this->select( $table, [ 'rowcount' => 'COUNT(*)' ], $conds, $fname, $options );
1491 $row = $this->fetchRow( $res );
1492 $rows = ( isset( $row['rowcount'] ) ) ?
(int)$row['rowcount'] : 0;
1498 public function selectRowCount(
1499 $tables, $vars = '*', $conds = '', $fname = __METHOD__
, $options = [], $join_conds = []
1502 $sql = $this->selectSQLText( $tables, '1', $conds, $fname, $options, $join_conds );
1503 $res = $this->query( "SELECT COUNT(*) AS rowcount FROM ($sql) tmp_count", $fname );
1506 $row = $this->fetchRow( $res );
1507 $rows = ( isset( $row['rowcount'] ) ) ?
(int)$row['rowcount'] : 0;
1514 * Removes most variables from an SQL query and replaces them with X or N for numbers.
1515 * It's only slightly flawed. Don't use for anything important.
1517 * @param string $sql A SQL Query
1521 protected static function generalizeSQL( $sql ) {
1522 # This does the same as the regexp below would do, but in such a way
1523 # as to avoid crashing php on some large strings.
1524 # $sql = preg_replace( "/'([^\\\\']|\\\\.)*'|\"([^\\\\\"]|\\\\.)*\"/", "'X'", $sql );
1526 $sql = str_replace( "\\\\", '', $sql );
1527 $sql = str_replace( "\\'", '', $sql );
1528 $sql = str_replace( "\\\"", '', $sql );
1529 $sql = preg_replace( "/'.*'/s", "'X'", $sql );
1530 $sql = preg_replace( '/".*"/s', "'X'", $sql );
1532 # All newlines, tabs, etc replaced by single space
1533 $sql = preg_replace( '/\s+/', ' ', $sql );
1536 # except the ones surrounded by characters, e.g. l10n
1537 $sql = preg_replace( '/-?\d+(,-?\d+)+/s', 'N,...,N', $sql );
1538 $sql = preg_replace( '/(?<![a-zA-Z])-?\d+(?![a-zA-Z])/s', 'N', $sql );
1543 public function fieldExists( $table, $field, $fname = __METHOD__
) {
1544 $info = $this->fieldInfo( $table, $field );
1549 public function indexExists( $table, $index, $fname = __METHOD__
) {
1550 if ( !$this->tableExists( $table ) ) {
1554 $info = $this->indexInfo( $table, $index, $fname );
1555 if ( is_null( $info ) ) {
1558 return $info !== false;
1562 public function tableExists( $table, $fname = __METHOD__
) {
1563 $table = $this->tableName( $table );
1564 $old = $this->ignoreErrors( true );
1565 $res = $this->query( "SELECT 1 FROM $table LIMIT 1", $fname );
1566 $this->ignoreErrors( $old );
1571 public function indexUnique( $table, $index ) {
1572 $indexInfo = $this->indexInfo( $table, $index );
1574 if ( !$indexInfo ) {
1578 return !$indexInfo[0]->Non_unique
;
1582 * Helper for DatabaseBase::insert().
1584 * @param array $options
1587 protected function makeInsertOptions( $options ) {
1588 return implode( ' ', $options );
1591 public function insert( $table, $a, $fname = __METHOD__
, $options = [] ) {
1592 # No rows to insert, easy just return now
1593 if ( !count( $a ) ) {
1597 $table = $this->tableName( $table );
1599 if ( !is_array( $options ) ) {
1600 $options = [ $options ];
1604 if ( isset( $options['fileHandle'] ) ) {
1605 $fh = $options['fileHandle'];
1607 $options = $this->makeInsertOptions( $options );
1609 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
1611 $keys = array_keys( $a[0] );
1614 $keys = array_keys( $a );
1617 $sql = 'INSERT ' . $options .
1618 " INTO $table (" . implode( ',', $keys ) . ') VALUES ';
1622 foreach ( $a as $row ) {
1628 $sql .= '(' . $this->makeList( $row ) . ')';
1631 $sql .= '(' . $this->makeList( $a ) . ')';
1634 if ( $fh !== null && false === fwrite( $fh, $sql ) ) {
1636 } elseif ( $fh !== null ) {
1640 return (bool)$this->query( $sql, $fname );
1644 * Make UPDATE options array for DatabaseBase::makeUpdateOptions
1646 * @param array $options
1649 protected function makeUpdateOptionsArray( $options ) {
1650 if ( !is_array( $options ) ) {
1651 $options = [ $options ];
1656 if ( in_array( 'LOW_PRIORITY', $options ) ) {
1657 $opts[] = $this->lowPriorityOption();
1660 if ( in_array( 'IGNORE', $options ) ) {
1668 * Make UPDATE options for the DatabaseBase::update function
1670 * @param array $options The options passed to DatabaseBase::update
1673 protected function makeUpdateOptions( $options ) {
1674 $opts = $this->makeUpdateOptionsArray( $options );
1676 return implode( ' ', $opts );
1679 function update( $table, $values, $conds, $fname = __METHOD__
, $options = [] ) {
1680 $table = $this->tableName( $table );
1681 $opts = $this->makeUpdateOptions( $options );
1682 $sql = "UPDATE $opts $table SET " . $this->makeList( $values, LIST_SET
);
1684 if ( $conds !== [] && $conds !== '*' ) {
1685 $sql .= " WHERE " . $this->makeList( $conds, LIST_AND
);
1688 return $this->query( $sql, $fname );
1691 public function makeList( $a, $mode = LIST_COMMA
) {
1692 if ( !is_array( $a ) ) {
1693 throw new DBUnexpectedError( $this, 'DatabaseBase::makeList called with incorrect parameters' );
1699 foreach ( $a as $field => $value ) {
1701 if ( $mode == LIST_AND
) {
1703 } elseif ( $mode == LIST_OR
) {
1712 if ( ( $mode == LIST_AND ||
$mode == LIST_OR
) && is_numeric( $field ) ) {
1713 $list .= "($value)";
1714 } elseif ( ( $mode == LIST_SET
) && is_numeric( $field ) ) {
1716 } elseif ( ( $mode == LIST_AND ||
$mode == LIST_OR
) && is_array( $value ) ) {
1717 // Remove null from array to be handled separately if found
1718 $includeNull = false;
1719 foreach ( array_keys( $value, null, true ) as $nullKey ) {
1720 $includeNull = true;
1721 unset( $value[$nullKey] );
1723 if ( count( $value ) == 0 && !$includeNull ) {
1724 throw new MWException( __METHOD__
. ": empty input for field $field" );
1725 } elseif ( count( $value ) == 0 ) {
1726 // only check if $field is null
1727 $list .= "$field IS NULL";
1729 // IN clause contains at least one valid element
1730 if ( $includeNull ) {
1731 // Group subconditions to ensure correct precedence
1734 if ( count( $value ) == 1 ) {
1735 // Special-case single values, as IN isn't terribly efficient
1736 // Don't necessarily assume the single key is 0; we don't
1737 // enforce linear numeric ordering on other arrays here.
1738 $value = array_values( $value )[0];
1739 $list .= $field . " = " . $this->addQuotes( $value );
1741 $list .= $field . " IN (" . $this->makeList( $value ) . ") ";
1743 // if null present in array, append IS NULL
1744 if ( $includeNull ) {
1745 $list .= " OR $field IS NULL)";
1748 } elseif ( $value === null ) {
1749 if ( $mode == LIST_AND ||
$mode == LIST_OR
) {
1750 $list .= "$field IS ";
1751 } elseif ( $mode == LIST_SET
) {
1752 $list .= "$field = ";
1756 if ( $mode == LIST_AND ||
$mode == LIST_OR ||
$mode == LIST_SET
) {
1757 $list .= "$field = ";
1759 $list .= $mode == LIST_NAMES ?
$value : $this->addQuotes( $value );
1766 public function makeWhereFrom2d( $data, $baseKey, $subKey ) {
1769 foreach ( $data as $base => $sub ) {
1770 if ( count( $sub ) ) {
1771 $conds[] = $this->makeList(
1772 [ $baseKey => $base, $subKey => array_keys( $sub ) ],
1778 return $this->makeList( $conds, LIST_OR
);
1780 // Nothing to search for...
1786 * Return aggregated value alias
1788 * @param array $valuedata
1789 * @param string $valuename
1793 public function aggregateValue( $valuedata, $valuename = 'value' ) {
1797 public function bitNot( $field ) {
1801 public function bitAnd( $fieldLeft, $fieldRight ) {
1802 return "($fieldLeft & $fieldRight)";
1805 public function bitOr( $fieldLeft, $fieldRight ) {
1806 return "($fieldLeft | $fieldRight)";
1809 public function buildConcat( $stringList ) {
1810 return 'CONCAT(' . implode( ',', $stringList ) . ')';
1813 public function buildGroupConcatField(
1814 $delim, $table, $field, $conds = '', $join_conds = []
1816 $fld = "GROUP_CONCAT($field SEPARATOR " . $this->addQuotes( $delim ) . ')';
1818 return '(' . $this->selectSQLText( $table, $fld, $conds, null, [], $join_conds ) . ')';
1822 * @param string $field Field or column to cast
1826 public function buildStringCast( $field ) {
1830 public function selectDB( $db ) {
1831 # Stub. Shouldn't cause serious problems if it's not overridden, but
1832 # if your database engine supports a concept similar to MySQL's
1833 # databases you may as well.
1834 $this->mDBname
= $db;
1839 public function getDBname() {
1840 return $this->mDBname
;
1843 public function getServer() {
1844 return $this->mServer
;
1848 * Format a table name ready for use in constructing an SQL query
1850 * This does two important things: it quotes the table names to clean them up,
1851 * and it adds a table prefix if only given a table name with no quotes.
1853 * All functions of this object which require a table name call this function
1854 * themselves. Pass the canonical name to such functions. This is only needed
1855 * when calling query() directly.
1857 * @note This function does not sanitize user input. It is not safe to use
1858 * this function to escape user input.
1859 * @param string $name Database table name
1860 * @param string $format One of:
1861 * quoted - Automatically pass the table name through addIdentifierQuotes()
1862 * so that it can be used in a query.
1863 * raw - Do not add identifier quotes to the table name
1864 * @return string Full database name
1866 public function tableName( $name, $format = 'quoted' ) {
1867 global $wgSharedDB, $wgSharedPrefix, $wgSharedTables, $wgSharedSchema;
1868 # Skip the entire process when we have a string quoted on both ends.
1869 # Note that we check the end so that we will still quote any use of
1870 # use of `database`.table. But won't break things if someone wants
1871 # to query a database table with a dot in the name.
1872 if ( $this->isQuotedIdentifier( $name ) ) {
1876 # Lets test for any bits of text that should never show up in a table
1877 # name. Basically anything like JOIN or ON which are actually part of
1878 # SQL queries, but may end up inside of the table value to combine
1879 # sql. Such as how the API is doing.
1880 # Note that we use a whitespace test rather than a \b test to avoid
1881 # any remote case where a word like on may be inside of a table name
1882 # surrounded by symbols which may be considered word breaks.
1883 if ( preg_match( '/(^|\s)(DISTINCT|JOIN|ON|AS)(\s|$)/i', $name ) !== 0 ) {
1887 # Split database and table into proper variables.
1888 # We reverse the explode so that database.table and table both output
1889 # the correct table.
1890 $dbDetails = explode( '.', $name, 3 );
1891 if ( count( $dbDetails ) == 3 ) {
1892 list( $database, $schema, $table ) = $dbDetails;
1893 # We don't want any prefix added in this case
1895 } elseif ( count( $dbDetails ) == 2 ) {
1896 list( $database, $table ) = $dbDetails;
1897 # We don't want any prefix added in this case
1898 # In dbs that support it, $database may actually be the schema
1899 # but that doesn't affect any of the functionality here
1903 list( $table ) = $dbDetails;
1904 if ( $wgSharedDB !== null # We have a shared database
1905 && $this->mForeign
== false # We're not working on a foreign database
1906 && !$this->isQuotedIdentifier( $table ) # Prevent shared tables listing '`table`'
1907 && in_array( $table, $wgSharedTables ) # A shared table is selected
1909 $database = $wgSharedDB;
1910 $schema = $wgSharedSchema === null ?
$this->mSchema
: $wgSharedSchema;
1911 $prefix = $wgSharedPrefix === null ?
$this->mTablePrefix
: $wgSharedPrefix;
1914 $schema = $this->mSchema
; # Default schema
1915 $prefix = $this->mTablePrefix
; # Default prefix
1919 # Quote $table and apply the prefix if not quoted.
1920 # $tableName might be empty if this is called from Database::replaceVars()
1921 $tableName = "{$prefix}{$table}";
1922 if ( $format == 'quoted' && !$this->isQuotedIdentifier( $tableName ) && $tableName !== '' ) {
1923 $tableName = $this->addIdentifierQuotes( $tableName );
1926 # Quote $schema and merge it with the table name if needed
1927 if ( strlen( $schema ) ) {
1928 if ( $format == 'quoted' && !$this->isQuotedIdentifier( $schema ) ) {
1929 $schema = $this->addIdentifierQuotes( $schema );
1931 $tableName = $schema . '.' . $tableName;
1934 # Quote $database and merge it with the table name if needed
1935 if ( $database !== null ) {
1936 if ( $format == 'quoted' && !$this->isQuotedIdentifier( $database ) ) {
1937 $database = $this->addIdentifierQuotes( $database );
1939 $tableName = $database . '.' . $tableName;
1946 * Fetch a number of table names into an array
1947 * This is handy when you need to construct SQL for joins
1950 * extract( $dbr->tableNames( 'user', 'watchlist' ) );
1951 * $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user
1952 * WHERE wl_user=user_id AND wl_user=$nameWithQuotes";
1956 public function tableNames() {
1957 $inArray = func_get_args();
1960 foreach ( $inArray as $name ) {
1961 $retVal[$name] = $this->tableName( $name );
1968 * Fetch a number of table names into an zero-indexed numerical array
1969 * This is handy when you need to construct SQL for joins
1972 * list( $user, $watchlist ) = $dbr->tableNamesN( 'user', 'watchlist' );
1973 * $sql = "SELECT wl_namespace,wl_title FROM $watchlist,$user
1974 * WHERE wl_user=user_id AND wl_user=$nameWithQuotes";
1978 public function tableNamesN() {
1979 $inArray = func_get_args();
1982 foreach ( $inArray as $name ) {
1983 $retVal[] = $this->tableName( $name );
1990 * Get an aliased table name
1991 * e.g. tableName AS newTableName
1993 * @param string $name Table name, see tableName()
1994 * @param string|bool $alias Alias (optional)
1995 * @return string SQL name for aliased table. Will not alias a table to its own name
1997 public function tableNameWithAlias( $name, $alias = false ) {
1998 if ( !$alias ||
$alias == $name ) {
1999 return $this->tableName( $name );
2001 return $this->tableName( $name ) . ' ' . $this->addIdentifierQuotes( $alias );
2006 * Gets an array of aliased table names
2008 * @param array $tables [ [alias] => table ]
2009 * @return string[] See tableNameWithAlias()
2011 public function tableNamesWithAlias( $tables ) {
2013 foreach ( $tables as $alias => $table ) {
2014 if ( is_numeric( $alias ) ) {
2017 $retval[] = $this->tableNameWithAlias( $table, $alias );
2024 * Get an aliased field name
2025 * e.g. fieldName AS newFieldName
2027 * @param string $name Field name
2028 * @param string|bool $alias Alias (optional)
2029 * @return string SQL name for aliased field. Will not alias a field to its own name
2031 public function fieldNameWithAlias( $name, $alias = false ) {
2032 if ( !$alias ||
(string)$alias === (string)$name ) {
2035 return $name . ' AS ' . $this->addIdentifierQuotes( $alias ); // PostgreSQL needs AS
2040 * Gets an array of aliased field names
2042 * @param array $fields [ [alias] => field ]
2043 * @return string[] See fieldNameWithAlias()
2045 public function fieldNamesWithAlias( $fields ) {
2047 foreach ( $fields as $alias => $field ) {
2048 if ( is_numeric( $alias ) ) {
2051 $retval[] = $this->fieldNameWithAlias( $field, $alias );
2058 * Get the aliased table name clause for a FROM clause
2059 * which might have a JOIN and/or USE INDEX or IGNORE INDEX clause
2061 * @param array $tables ( [alias] => table )
2062 * @param array $use_index Same as for select()
2063 * @param array $ignore_index Same as for select()
2064 * @param array $join_conds Same as for select()
2067 protected function tableNamesWithIndexClauseOrJOIN(
2068 $tables, $use_index = [], $ignore_index = [], $join_conds = []
2072 $use_index = (array)$use_index;
2073 $ignore_index = (array)$ignore_index;
2074 $join_conds = (array)$join_conds;
2076 foreach ( $tables as $alias => $table ) {
2077 if ( !is_string( $alias ) ) {
2078 // No alias? Set it equal to the table name
2081 // Is there a JOIN clause for this table?
2082 if ( isset( $join_conds[$alias] ) ) {
2083 list( $joinType, $conds ) = $join_conds[$alias];
2084 $tableClause = $joinType;
2085 $tableClause .= ' ' . $this->tableNameWithAlias( $table, $alias );
2086 if ( isset( $use_index[$alias] ) ) { // has USE INDEX?
2087 $use = $this->useIndexClause( implode( ',', (array)$use_index[$alias] ) );
2089 $tableClause .= ' ' . $use;
2092 if ( isset( $ignore_index[$alias] ) ) { // has IGNORE INDEX?
2093 $ignore = $this->ignoreIndexClause( implode( ',', (array)$ignore_index[$alias] ) );
2094 if ( $ignore != '' ) {
2095 $tableClause .= ' ' . $ignore;
2098 $on = $this->makeList( (array)$conds, LIST_AND
);
2100 $tableClause .= ' ON (' . $on . ')';
2103 $retJOIN[] = $tableClause;
2104 } elseif ( isset( $use_index[$alias] ) ) {
2105 // Is there an INDEX clause for this table?
2106 $tableClause = $this->tableNameWithAlias( $table, $alias );
2107 $tableClause .= ' ' . $this->useIndexClause(
2108 implode( ',', (array)$use_index[$alias] )
2111 $ret[] = $tableClause;
2112 } elseif ( isset( $ignore_index[$alias] ) ) {
2113 // Is there an INDEX clause for this table?
2114 $tableClause = $this->tableNameWithAlias( $table, $alias );
2115 $tableClause .= ' ' . $this->ignoreIndexClause(
2116 implode( ',', (array)$ignore_index[$alias] )
2119 $ret[] = $tableClause;
2121 $tableClause = $this->tableNameWithAlias( $table, $alias );
2123 $ret[] = $tableClause;
2127 // We can't separate explicit JOIN clauses with ',', use ' ' for those
2128 $implicitJoins = !empty( $ret ) ?
implode( ',', $ret ) : "";
2129 $explicitJoins = !empty( $retJOIN ) ?
implode( ' ', $retJOIN ) : "";
2131 // Compile our final table clause
2132 return implode( ' ', [ $implicitJoins, $explicitJoins ] );
2136 * Get the name of an index in a given table.
2138 * @param string $index
2141 protected function indexName( $index ) {
2142 // Backwards-compatibility hack
2144 'ar_usertext_timestamp' => 'usertext_timestamp',
2145 'un_user_id' => 'user_id',
2146 'un_user_ip' => 'user_ip',
2149 if ( isset( $renamed[$index] ) ) {
2150 return $renamed[$index];
2156 public function addQuotes( $s ) {
2157 if ( $s instanceof Blob
) {
2160 if ( $s === null ) {
2163 # This will also quote numeric values. This should be harmless,
2164 # and protects against weird problems that occur when they really
2165 # _are_ strings such as article titles and string->number->string
2166 # conversion is not 1:1.
2167 return "'" . $this->strencode( $s ) . "'";
2172 * Quotes an identifier using `backticks` or "double quotes" depending on the database type.
2173 * MySQL uses `backticks` while basically everything else uses double quotes.
2174 * Since MySQL is the odd one out here the double quotes are our generic
2175 * and we implement backticks in DatabaseMysql.
2180 public function addIdentifierQuotes( $s ) {
2181 return '"' . str_replace( '"', '""', $s ) . '"';
2185 * Returns if the given identifier looks quoted or not according to
2186 * the database convention for quoting identifiers .
2188 * @note Do not use this to determine if untrusted input is safe.
2189 * A malicious user can trick this function.
2190 * @param string $name
2193 public function isQuotedIdentifier( $name ) {
2194 return $name[0] == '"' && substr( $name, -1, 1 ) == '"';
2201 protected function escapeLikeInternal( $s ) {
2202 return addcslashes( $s, '\%_' );
2205 public function buildLike() {
2206 $params = func_get_args();
2208 if ( count( $params ) > 0 && is_array( $params[0] ) ) {
2209 $params = $params[0];
2214 foreach ( $params as $value ) {
2215 if ( $value instanceof LikeMatch
) {
2216 $s .= $value->toString();
2218 $s .= $this->escapeLikeInternal( $value );
2222 return " LIKE {$this->addQuotes( $s )} ";
2225 public function anyChar() {
2226 return new LikeMatch( '_' );
2229 public function anyString() {
2230 return new LikeMatch( '%' );
2233 public function nextSequenceValue( $seqName ) {
2238 * USE INDEX clause. Unlikely to be useful for anything but MySQL. This
2239 * is only needed because a) MySQL must be as efficient as possible due to
2240 * its use on Wikipedia, and b) MySQL 4.0 is kind of dumb sometimes about
2241 * which index to pick. Anyway, other databases might have different
2242 * indexes on a given table. So don't bother overriding this unless you're
2244 * @param string $index
2247 public function useIndexClause( $index ) {
2252 * IGNORE INDEX clause. Unlikely to be useful for anything but MySQL. This
2253 * is only needed because a) MySQL must be as efficient as possible due to
2254 * its use on Wikipedia, and b) MySQL 4.0 is kind of dumb sometimes about
2255 * which index to pick. Anyway, other databases might have different
2256 * indexes on a given table. So don't bother overriding this unless you're
2258 * @param string $index
2261 public function ignoreIndexClause( $index ) {
2265 public function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__
) {
2266 $quotedTable = $this->tableName( $table );
2268 if ( count( $rows ) == 0 ) {
2273 if ( !is_array( reset( $rows ) ) ) {
2277 // @FXIME: this is not atomic, but a trx would break affectedRows()
2278 foreach ( $rows as $row ) {
2279 # Delete rows which collide
2280 if ( $uniqueIndexes ) {
2281 $sql = "DELETE FROM $quotedTable WHERE ";
2283 foreach ( $uniqueIndexes as $index ) {
2290 if ( is_array( $index ) ) {
2292 foreach ( $index as $col ) {
2298 $sql .= $col . '=' . $this->addQuotes( $row[$col] );
2301 $sql .= $index . '=' . $this->addQuotes( $row[$index] );
2305 $this->query( $sql, $fname );
2308 # Now insert the row
2309 $this->insert( $table, $row, $fname );
2314 * REPLACE query wrapper for MySQL and SQLite, which have a native REPLACE
2317 * @param string $table Table name
2318 * @param array|string $rows Row(s) to insert
2319 * @param string $fname Caller function name
2321 * @return ResultWrapper
2323 protected function nativeReplace( $table, $rows, $fname ) {
2324 $table = $this->tableName( $table );
2327 if ( !is_array( reset( $rows ) ) ) {
2331 $sql = "REPLACE INTO $table (" . implode( ',', array_keys( $rows[0] ) ) . ') VALUES ';
2334 foreach ( $rows as $row ) {
2341 $sql .= '(' . $this->makeList( $row ) . ')';
2344 return $this->query( $sql, $fname );
2347 public function upsert( $table, array $rows, array $uniqueIndexes, array $set,
2350 if ( !count( $rows ) ) {
2351 return true; // nothing to do
2354 if ( !is_array( reset( $rows ) ) ) {
2358 if ( count( $uniqueIndexes ) ) {
2359 $clauses = []; // list WHERE clauses that each identify a single row
2360 foreach ( $rows as $row ) {
2361 foreach ( $uniqueIndexes as $index ) {
2362 $index = is_array( $index ) ?
$index : [ $index ]; // columns
2363 $rowKey = []; // unique key to this row
2364 foreach ( $index as $column ) {
2365 $rowKey[$column] = $row[$column];
2367 $clauses[] = $this->makeList( $rowKey, LIST_AND
);
2370 $where = [ $this->makeList( $clauses, LIST_OR
) ];
2375 $useTrx = !$this->mTrxLevel
;
2377 $this->begin( $fname, self
::TRANSACTION_INTERNAL
);
2380 # Update any existing conflicting row(s)
2381 if ( $where !== false ) {
2382 $ok = $this->update( $table, $set, $where, $fname );
2386 # Now insert any non-conflicting row(s)
2387 $ok = $this->insert( $table, $rows, $fname, [ 'IGNORE' ] ) && $ok;
2388 } catch ( Exception
$e ) {
2390 $this->rollback( $fname, self
::FLUSHING_INTERNAL
);
2395 $this->commit( $fname, self
::FLUSHING_INTERNAL
);
2401 public function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds,
2405 throw new DBUnexpectedError( $this,
2406 'DatabaseBase::deleteJoin() called with empty $conds' );
2409 $delTable = $this->tableName( $delTable );
2410 $joinTable = $this->tableName( $joinTable );
2411 $sql = "DELETE FROM $delTable WHERE $delVar IN (SELECT $joinVar FROM $joinTable ";
2412 if ( $conds != '*' ) {
2413 $sql .= 'WHERE ' . $this->makeList( $conds, LIST_AND
);
2417 $this->query( $sql, $fname );
2421 * Returns the size of a text field, or -1 for "unlimited"
2423 * @param string $table
2424 * @param string $field
2427 public function textFieldSize( $table, $field ) {
2428 $table = $this->tableName( $table );
2429 $sql = "SHOW COLUMNS FROM $table LIKE \"$field\";";
2430 $res = $this->query( $sql, 'DatabaseBase::textFieldSize' );
2431 $row = $this->fetchObject( $res );
2435 if ( preg_match( '/\((.*)\)/', $row->Type
, $m ) ) {
2445 * A string to insert into queries to show that they're low-priority, like
2446 * MySQL's LOW_PRIORITY. If no such feature exists, return an empty
2447 * string and nothing bad should happen.
2449 * @return string Returns the text of the low priority option if it is
2450 * supported, or a blank string otherwise
2452 public function lowPriorityOption() {
2456 public function delete( $table, $conds, $fname = __METHOD__
) {
2458 throw new DBUnexpectedError( $this, 'DatabaseBase::delete() called with no conditions' );
2461 $table = $this->tableName( $table );
2462 $sql = "DELETE FROM $table";
2464 if ( $conds != '*' ) {
2465 if ( is_array( $conds ) ) {
2466 $conds = $this->makeList( $conds, LIST_AND
);
2468 $sql .= ' WHERE ' . $conds;
2471 return $this->query( $sql, $fname );
2474 public function insertSelect(
2475 $destTable, $srcTable, $varMap, $conds,
2476 $fname = __METHOD__
, $insertOptions = [], $selectOptions = []
2478 if ( $this->cliMode
) {
2479 // For massive migrations with downtime, we don't want to select everything
2480 // into memory and OOM, so do all this native on the server side if possible.
2481 return $this->nativeInsertSelect(
2492 // For web requests, do a locking SELECT and then INSERT. This puts the SELECT burden
2493 // on only the master (without needing row-based-replication). It also makes it easy to
2494 // know how big the INSERT is going to be.
2496 foreach ( $varMap as $dstColumn => $sourceColumnOrSql ) {
2497 $fields[] = $this->fieldNameWithAlias( $sourceColumnOrSql, $dstColumn );
2499 $selectOptions[] = 'FOR UPDATE';
2500 $res = $this->select( $srcTable, implode( ',', $fields ), $conds, $fname, $selectOptions );
2506 foreach ( $res as $row ) {
2507 $rows[] = (array)$row;
2510 return $this->insert( $destTable, $rows, $fname, $insertOptions );
2513 public function nativeInsertSelect( $destTable, $srcTable, $varMap, $conds,
2514 $fname = __METHOD__
,
2515 $insertOptions = [], $selectOptions = []
2517 $destTable = $this->tableName( $destTable );
2519 if ( !is_array( $insertOptions ) ) {
2520 $insertOptions = [ $insertOptions ];
2523 $insertOptions = $this->makeInsertOptions( $insertOptions );
2525 if ( !is_array( $selectOptions ) ) {
2526 $selectOptions = [ $selectOptions ];
2529 list( $startOpts, $useIndex, $tailOpts, $ignoreIndex ) = $this->makeSelectOptions(
2532 if ( is_array( $srcTable ) ) {
2533 $srcTable = implode( ',', array_map( [ &$this, 'tableName' ], $srcTable ) );
2535 $srcTable = $this->tableName( $srcTable );
2538 $sql = "INSERT $insertOptions INTO $destTable (" . implode( ',', array_keys( $varMap ) ) . ')' .
2539 " SELECT $startOpts " . implode( ',', $varMap ) .
2540 " FROM $srcTable $useIndex $ignoreIndex ";
2542 if ( $conds != '*' ) {
2543 if ( is_array( $conds ) ) {
2544 $conds = $this->makeList( $conds, LIST_AND
);
2546 $sql .= " WHERE $conds";
2549 $sql .= " $tailOpts";
2551 return $this->query( $sql, $fname );
2555 * Construct a LIMIT query with optional offset. This is used for query
2556 * pages. The SQL should be adjusted so that only the first $limit rows
2557 * are returned. If $offset is provided as well, then the first $offset
2558 * rows should be discarded, and the next $limit rows should be returned.
2559 * If the result of the query is not ordered, then the rows to be returned
2560 * are theoretically arbitrary.
2562 * $sql is expected to be a SELECT, if that makes a difference.
2564 * The version provided by default works in MySQL and SQLite. It will very
2565 * likely need to be overridden for most other DBMSes.
2567 * @param string $sql SQL query we will append the limit too
2568 * @param int $limit The SQL limit
2569 * @param int|bool $offset The SQL offset (default false)
2570 * @throws DBUnexpectedError
2573 public function limitResult( $sql, $limit, $offset = false ) {
2574 if ( !is_numeric( $limit ) ) {
2575 throw new DBUnexpectedError( $this, "Invalid non-numeric limit passed to limitResult()\n" );
2578 return "$sql LIMIT "
2579 . ( ( is_numeric( $offset ) && $offset != 0 ) ?
"{$offset}," : "" )
2583 public function unionSupportsOrderAndLimit() {
2584 return true; // True for almost every DB supported
2587 public function unionQueries( $sqls, $all ) {
2588 $glue = $all ?
') UNION ALL (' : ') UNION (';
2590 return '(' . implode( $glue, $sqls ) . ')';
2593 public function conditional( $cond, $trueVal, $falseVal ) {
2594 if ( is_array( $cond ) ) {
2595 $cond = $this->makeList( $cond, LIST_AND
);
2598 return " (CASE WHEN $cond THEN $trueVal ELSE $falseVal END) ";
2601 public function strreplace( $orig, $old, $new ) {
2602 return "REPLACE({$orig}, {$old}, {$new})";
2605 public function getServerUptime() {
2609 public function wasDeadlock() {
2613 public function wasLockTimeout() {
2617 public function wasErrorReissuable() {
2621 public function wasReadOnlyError() {
2626 * Determines if the given query error was a connection drop
2629 * @param integer|string $errno
2632 public function wasConnectionError( $errno ) {
2637 * Perform a deadlock-prone transaction.
2639 * This function invokes a callback function to perform a set of write
2640 * queries. If a deadlock occurs during the processing, the transaction
2641 * will be rolled back and the callback function will be called again.
2643 * Avoid using this method outside of Job or Maintenance classes.
2646 * $dbw->deadlockLoop( callback, ... );
2648 * Extra arguments are passed through to the specified callback function.
2649 * This method requires that no transactions are already active to avoid
2650 * causing premature commits or exceptions.
2652 * Returns whatever the callback function returned on its successful,
2653 * iteration, or false on error, for example if the retry limit was
2657 * @throws DBUnexpectedError
2660 public function deadlockLoop() {
2661 $args = func_get_args();
2662 $function = array_shift( $args );
2663 $tries = self
::DEADLOCK_TRIES
;
2665 $this->begin( __METHOD__
);
2668 /** @var Exception $e */
2672 $retVal = call_user_func_array( $function, $args );
2674 } catch ( DBQueryError
$e ) {
2675 if ( $this->wasDeadlock() ) {
2676 // Retry after a randomized delay
2677 usleep( mt_rand( self
::DEADLOCK_DELAY_MIN
, self
::DEADLOCK_DELAY_MAX
) );
2679 // Throw the error back up
2683 } while ( --$tries > 0 );
2685 if ( $tries <= 0 ) {
2686 // Too many deadlocks; give up
2687 $this->rollback( __METHOD__
);
2690 $this->commit( __METHOD__
);
2696 public function masterPosWait( DBMasterPos
$pos, $timeout ) {
2697 # Real waits are implemented in the subclass.
2701 public function getSlavePos() {
2706 public function getMasterPos() {
2711 public function serverIsReadOnly() {
2715 final public function onTransactionResolution( callable
$callback ) {
2716 if ( !$this->mTrxLevel
) {
2717 throw new DBUnexpectedError( $this, "No transaction is active." );
2719 $this->mTrxEndCallbacks
[] = [ $callback, wfGetCaller() ];
2722 final public function onTransactionIdle( callable
$callback ) {
2723 $this->mTrxIdleCallbacks
[] = [ $callback, wfGetCaller() ];
2724 if ( !$this->mTrxLevel
) {
2725 $this->runOnTransactionIdleCallbacks( self
::TRIGGER_IDLE
);
2729 final public function onTransactionPreCommitOrIdle( callable
$callback ) {
2730 if ( $this->mTrxLevel
) {
2731 $this->mTrxPreCommitCallbacks
[] = [ $callback, wfGetCaller() ];
2733 // If no transaction is active, then make one for this callback
2734 $this->startAtomic( __METHOD__
);
2736 call_user_func( $callback );
2737 $this->endAtomic( __METHOD__
);
2738 } catch ( Exception
$e ) {
2739 $this->rollback( __METHOD__
, self
::FLUSHING_INTERNAL
);
2745 final public function setTransactionListener( $name, callable
$callback = null ) {
2747 $this->mTrxRecurringCallbacks
[$name] = [ $callback, wfGetCaller() ];
2749 unset( $this->mTrxRecurringCallbacks
[$name] );
2754 * Whether to disable running of post-COMMIT/ROLLBACK callbacks
2756 * This method should not be used outside of Database/LoadBalancer
2758 * @param bool $suppress
2761 final public function setTrxEndCallbackSuppression( $suppress ) {
2762 $this->mTrxEndCallbacksSuppressed
= $suppress;
2766 * Actually run and consume any "on transaction idle/resolution" callbacks.
2768 * This method should not be used outside of Database/LoadBalancer
2770 * @param integer $trigger IDatabase::TRIGGER_* constant
2774 public function runOnTransactionIdleCallbacks( $trigger ) {
2775 if ( $this->mTrxEndCallbacksSuppressed
) {
2779 $autoTrx = $this->getFlag( DBO_TRX
); // automatic begin() enabled?
2780 /** @var Exception $e */
2781 $e = null; // first exception
2782 do { // callbacks may add callbacks :)
2783 $callbacks = array_merge(
2784 $this->mTrxIdleCallbacks
,
2785 $this->mTrxEndCallbacks
// include "transaction resolution" callbacks
2787 $this->mTrxIdleCallbacks
= []; // consumed (and recursion guard)
2788 $this->mTrxEndCallbacks
= []; // consumed (recursion guard)
2789 foreach ( $callbacks as $callback ) {
2791 list( $phpCallback ) = $callback;
2792 $this->clearFlag( DBO_TRX
); // make each query its own transaction
2793 call_user_func_array( $phpCallback, [ $trigger ] );
2795 $this->setFlag( DBO_TRX
); // restore automatic begin()
2797 $this->clearFlag( DBO_TRX
); // restore auto-commit
2799 } catch ( Exception
$ex ) {
2800 MWExceptionHandler
::logException( $ex );
2802 // Some callbacks may use startAtomic/endAtomic, so make sure
2803 // their transactions are ended so other callbacks don't fail
2804 if ( $this->trxLevel() ) {
2805 $this->rollback( __METHOD__
, self
::FLUSHING_INTERNAL
);
2809 } while ( count( $this->mTrxIdleCallbacks
) );
2811 if ( $e instanceof Exception
) {
2812 throw $e; // re-throw any first exception
2817 * Actually run and consume any "on transaction pre-commit" callbacks.
2819 * This method should not be used outside of Database/LoadBalancer
2824 public function runOnTransactionPreCommitCallbacks() {
2825 $e = null; // first exception
2826 do { // callbacks may add callbacks :)
2827 $callbacks = $this->mTrxPreCommitCallbacks
;
2828 $this->mTrxPreCommitCallbacks
= []; // consumed (and recursion guard)
2829 foreach ( $callbacks as $callback ) {
2831 list( $phpCallback ) = $callback;
2832 call_user_func( $phpCallback );
2833 } catch ( Exception
$ex ) {
2834 MWExceptionHandler
::logException( $ex );
2838 } while ( count( $this->mTrxPreCommitCallbacks
) );
2840 if ( $e instanceof Exception
) {
2841 throw $e; // re-throw any first exception
2846 * Actually run any "transaction listener" callbacks.
2848 * This method should not be used outside of Database/LoadBalancer
2850 * @param integer $trigger IDatabase::TRIGGER_* constant
2854 public function runTransactionListenerCallbacks( $trigger ) {
2855 if ( $this->mTrxEndCallbacksSuppressed
) {
2859 /** @var Exception $e */
2860 $e = null; // first exception
2862 foreach ( $this->mTrxRecurringCallbacks
as $callback ) {
2864 list( $phpCallback ) = $callback;
2865 $phpCallback( $trigger, $this );
2866 } catch ( Exception
$ex ) {
2867 MWExceptionHandler
::logException( $ex );
2872 if ( $e instanceof Exception
) {
2873 throw $e; // re-throw any first exception
2877 final public function startAtomic( $fname = __METHOD__
) {
2878 if ( !$this->mTrxLevel
) {
2879 $this->begin( $fname, self
::TRANSACTION_INTERNAL
);
2880 // If DBO_TRX is set, a series of startAtomic/endAtomic pairs will result
2881 // in all changes being in one transaction to keep requests transactional.
2882 if ( !$this->getFlag( DBO_TRX
) ) {
2883 $this->mTrxAutomaticAtomic
= true;
2887 $this->mTrxAtomicLevels
[] = $fname;
2890 final public function endAtomic( $fname = __METHOD__
) {
2891 if ( !$this->mTrxLevel
) {
2892 throw new DBUnexpectedError( $this, "No atomic transaction is open (got $fname)." );
2894 if ( !$this->mTrxAtomicLevels ||
2895 array_pop( $this->mTrxAtomicLevels
) !== $fname
2897 throw new DBUnexpectedError( $this, "Invalid atomic section ended (got $fname)." );
2900 if ( !$this->mTrxAtomicLevels
&& $this->mTrxAutomaticAtomic
) {
2901 $this->commit( $fname, self
::FLUSHING_INTERNAL
);
2905 final public function doAtomicSection( $fname, callable
$callback ) {
2906 $this->startAtomic( $fname );
2908 $res = call_user_func_array( $callback, [ $this, $fname ] );
2909 } catch ( Exception
$e ) {
2910 $this->rollback( $fname, self
::FLUSHING_INTERNAL
);
2913 $this->endAtomic( $fname );
2918 final public function begin( $fname = __METHOD__
, $mode = self
::TRANSACTION_EXPLICIT
) {
2919 // Protect against mismatched atomic section, transaction nesting, and snapshot loss
2920 if ( $this->mTrxLevel
) {
2921 if ( $this->mTrxAtomicLevels
) {
2922 $levels = implode( ', ', $this->mTrxAtomicLevels
);
2923 $msg = "$fname: Got explicit BEGIN while atomic section(s) $levels are open.";
2924 throw new DBUnexpectedError( $this, $msg );
2925 } elseif ( !$this->mTrxAutomatic
) {
2926 $msg = "$fname: Explicit transaction already active (from {$this->mTrxFname}).";
2927 throw new DBUnexpectedError( $this, $msg );
2929 // @TODO: make this an exception at some point
2930 $msg = "$fname: Implicit transaction already active (from {$this->mTrxFname}).";
2931 wfLogDBError( $msg );
2933 return; // join the main transaction set
2935 } elseif ( $this->getFlag( DBO_TRX
) && $mode !== self
::TRANSACTION_INTERNAL
) {
2936 // @TODO: make this an exception at some point
2937 $msg = "$fname: Implicit transaction expected (DBO_TRX set).";
2938 wfLogDBError( $msg );
2940 return; // let any writes be in the main transaction
2943 // Avoid fatals if close() was called
2944 $this->assertOpen();
2946 $this->doBegin( $fname );
2947 $this->mTrxTimestamp
= microtime( true );
2948 $this->mTrxFname
= $fname;
2949 $this->mTrxDoneWrites
= false;
2950 $this->mTrxAutomatic
= ( $mode === self
::TRANSACTION_INTERNAL
);
2951 $this->mTrxAutomaticAtomic
= false;
2952 $this->mTrxAtomicLevels
= [];
2953 $this->mTrxShortId
= wfRandomString( 12 );
2954 $this->mTrxWriteDuration
= 0.0;
2955 $this->mTrxWriteQueryCount
= 0;
2956 $this->mTrxWriteAdjDuration
= 0.0;
2957 $this->mTrxWriteAdjQueryCount
= 0;
2958 $this->mTrxWriteCallers
= [];
2959 // First SELECT after BEGIN will establish the snapshot in REPEATABLE-READ.
2960 // Get an estimate of the replica DB lag before then, treating estimate staleness
2961 // as lag itself just to be safe
2962 $status = $this->getApproximateLagStatus();
2963 $this->mTrxReplicaLag
= $status['lag'] +
( microtime( true ) - $status['since'] );
2967 * Issues the BEGIN command to the database server.
2969 * @see DatabaseBase::begin()
2970 * @param string $fname
2972 protected function doBegin( $fname ) {
2973 $this->query( 'BEGIN', $fname );
2974 $this->mTrxLevel
= 1;
2977 final public function commit( $fname = __METHOD__
, $flush = '' ) {
2978 if ( $this->mTrxLevel
&& $this->mTrxAtomicLevels
) {
2979 // There are still atomic sections open. This cannot be ignored
2980 $levels = implode( ', ', $this->mTrxAtomicLevels
);
2981 throw new DBUnexpectedError(
2983 "$fname: Got COMMIT while atomic sections $levels are still open."
2987 if ( $flush === self
::FLUSHING_INTERNAL ||
$flush === self
::FLUSHING_ALL_PEERS
) {
2988 if ( !$this->mTrxLevel
) {
2989 return; // nothing to do
2990 } elseif ( !$this->mTrxAutomatic
) {
2991 throw new DBUnexpectedError(
2993 "$fname: Flushing an explicit transaction, getting out of sync."
2997 if ( !$this->mTrxLevel
) {
2998 wfWarn( "$fname: No transaction to commit, something got out of sync." );
2999 return; // nothing to do
3000 } elseif ( $this->mTrxAutomatic
) {
3001 // @TODO: make this an exception at some point
3002 $msg = "$fname: Explicit commit of implicit transaction.";
3003 wfLogDBError( $msg );
3005 return; // wait for the main transaction set commit round
3009 // Avoid fatals if close() was called
3010 $this->assertOpen();
3012 $this->runOnTransactionPreCommitCallbacks();
3013 $writeTime = $this->pendingWriteQueryDuration( self
::ESTIMATE_DB_APPLY
);
3014 $this->doCommit( $fname );
3015 if ( $this->mTrxDoneWrites
) {
3016 $this->mDoneWrites
= microtime( true );
3017 $this->getTransactionProfiler()->transactionWritingOut(
3018 $this->mServer
, $this->mDBname
, $this->mTrxShortId
, $writeTime );
3021 $this->runOnTransactionIdleCallbacks( self
::TRIGGER_COMMIT
);
3022 $this->runTransactionListenerCallbacks( self
::TRIGGER_COMMIT
);
3026 * Issues the COMMIT command to the database server.
3028 * @see DatabaseBase::commit()
3029 * @param string $fname
3031 protected function doCommit( $fname ) {
3032 if ( $this->mTrxLevel
) {
3033 $this->query( 'COMMIT', $fname );
3034 $this->mTrxLevel
= 0;
3038 final public function rollback( $fname = __METHOD__
, $flush = '' ) {
3039 if ( $flush === self
::FLUSHING_INTERNAL ||
$flush === self
::FLUSHING_ALL_PEERS
) {
3040 if ( !$this->mTrxLevel
) {
3041 return; // nothing to do
3044 if ( !$this->mTrxLevel
) {
3045 wfWarn( "$fname: No transaction to rollback, something got out of sync." );
3046 return; // nothing to do
3047 } elseif ( $this->getFlag( DBO_TRX
) ) {
3048 throw new DBUnexpectedError(
3050 "$fname: Expected mass rollback of all peer databases (DBO_TRX set)."
3055 // Avoid fatals if close() was called
3056 $this->assertOpen();
3058 $this->doRollback( $fname );
3059 $this->mTrxAtomicLevels
= [];
3060 if ( $this->mTrxDoneWrites
) {
3061 $this->getTransactionProfiler()->transactionWritingOut(
3062 $this->mServer
, $this->mDBname
, $this->mTrxShortId
);
3065 $this->mTrxIdleCallbacks
= []; // clear
3066 $this->mTrxPreCommitCallbacks
= []; // clear
3067 $this->runOnTransactionIdleCallbacks( self
::TRIGGER_ROLLBACK
);
3068 $this->runTransactionListenerCallbacks( self
::TRIGGER_ROLLBACK
);
3072 * Issues the ROLLBACK command to the database server.
3074 * @see DatabaseBase::rollback()
3075 * @param string $fname
3077 protected function doRollback( $fname ) {
3078 if ( $this->mTrxLevel
) {
3079 # Disconnects cause rollback anyway, so ignore those errors
3080 $ignoreErrors = true;
3081 $this->query( 'ROLLBACK', $fname, $ignoreErrors );
3082 $this->mTrxLevel
= 0;
3086 public function flushSnapshot( $fname = __METHOD__
) {
3087 if ( $this->writesOrCallbacksPending() ||
$this->explicitTrxActive() ) {
3088 // This only flushes transactions to clear snapshots, not to write data
3089 throw new DBUnexpectedError(
3091 "$fname: Cannot COMMIT to clear snapshot because writes are pending."
3095 $this->commit( $fname, self
::FLUSHING_INTERNAL
);
3098 public function explicitTrxActive() {
3099 return $this->mTrxLevel
&& ( $this->mTrxAtomicLevels ||
!$this->mTrxAutomatic
);
3103 * Creates a new table with structure copied from existing table
3104 * Note that unlike most database abstraction functions, this function does not
3105 * automatically append database prefix, because it works at a lower
3106 * abstraction level.
3107 * The table names passed to this function shall not be quoted (this
3108 * function calls addIdentifierQuotes when needed).
3110 * @param string $oldName Name of table whose structure should be copied
3111 * @param string $newName Name of table to be created
3112 * @param bool $temporary Whether the new table should be temporary
3113 * @param string $fname Calling function name
3114 * @throws MWException
3115 * @return bool True if operation was successful
3117 public function duplicateTableStructure( $oldName, $newName, $temporary = false,
3120 throw new MWException(
3121 'DatabaseBase::duplicateTableStructure is not implemented in descendant class' );
3124 function listTables( $prefix = null, $fname = __METHOD__
) {
3125 throw new MWException( 'DatabaseBase::listTables is not implemented in descendant class' );
3129 * Reset the views process cache set by listViews()
3132 final public function clearViewsCache() {
3133 $this->allViews
= null;
3137 * Lists all the VIEWs in the database
3139 * For caching purposes the list of all views should be stored in
3140 * $this->allViews. The process cache can be cleared with clearViewsCache()
3142 * @param string $prefix Only show VIEWs with this prefix, eg. unit_test_
3143 * @param string $fname Name of calling function
3144 * @throws MWException
3148 public function listViews( $prefix = null, $fname = __METHOD__
) {
3149 throw new MWException( 'DatabaseBase::listViews is not implemented in descendant class' );
3153 * Differentiates between a TABLE and a VIEW
3155 * @param string $name Name of the database-structure to test.
3156 * @throws MWException
3160 public function isView( $name ) {
3161 throw new MWException( 'DatabaseBase::isView is not implemented in descendant class' );
3164 public function timestamp( $ts = 0 ) {
3165 return wfTimestamp( TS_MW
, $ts );
3168 public function timestampOrNull( $ts = null ) {
3169 if ( is_null( $ts ) ) {
3172 return $this->timestamp( $ts );
3177 * Take the result from a query, and wrap it in a ResultWrapper if
3178 * necessary. Boolean values are passed through as is, to indicate success
3179 * of write queries or failure.
3181 * Once upon a time, DatabaseBase::query() returned a bare MySQL result
3182 * resource, and it was necessary to call this function to convert it to
3183 * a wrapper. Nowadays, raw database objects are never exposed to external
3184 * callers, so this is unnecessary in external code.
3186 * @param bool|ResultWrapper|resource|object $result
3187 * @return bool|ResultWrapper
3189 protected function resultObject( $result ) {
3192 } elseif ( $result instanceof ResultWrapper
) {
3194 } elseif ( $result === true ) {
3195 // Successful write query
3198 return new ResultWrapper( $this, $result );
3202 public function ping( &$rtt = null ) {
3203 // Avoid hitting the server if it was hit recently
3204 if ( $this->isOpen() && ( microtime( true ) - $this->lastPing
) < self
::PING_TTL
) {
3205 if ( !func_num_args() ||
$this->mRTTEstimate
> 0 ) {
3206 $rtt = $this->mRTTEstimate
;
3207 return true; // don't care about $rtt
3211 // This will reconnect if possible or return false if not
3212 $this->clearFlag( DBO_TRX
, self
::REMEMBER_PRIOR
);
3213 $ok = ( $this->query( self
::PING_QUERY
, __METHOD__
, true ) !== false );
3214 $this->restoreFlags( self
::RESTORE_PRIOR
);
3217 $rtt = $this->mRTTEstimate
;
3226 protected function reconnect() {
3227 $this->closeConnection();
3228 $this->mOpened
= false;
3229 $this->mConn
= false;
3231 $this->open( $this->mServer
, $this->mUser
, $this->mPassword
, $this->mDBname
);
3232 $this->lastPing
= microtime( true );
3234 } catch ( DBConnectionError
$e ) {
3241 public function getSessionLagStatus() {
3242 return $this->getTransactionLagStatus() ?
: $this->getApproximateLagStatus();
3246 * Get the replica DB lag when the current transaction started
3248 * This is useful when transactions might use snapshot isolation
3249 * (e.g. REPEATABLE-READ in innodb), so the "real" lag of that data
3250 * is this lag plus transaction duration. If they don't, it is still
3251 * safe to be pessimistic. This returns null if there is no transaction.
3253 * @return array|null ('lag': seconds or false on error, 'since': UNIX timestamp of BEGIN)
3256 public function getTransactionLagStatus() {
3257 return $this->mTrxLevel
3258 ?
[ 'lag' => $this->mTrxReplicaLag
, 'since' => $this->trxTimestamp() ]
3263 * Get a replica DB lag estimate for this server
3265 * @return array ('lag': seconds or false on error, 'since': UNIX timestamp of estimate)
3268 public function getApproximateLagStatus() {
3270 'lag' => $this->getLBInfo( 'replica' ) ?
$this->getLag() : 0,
3271 'since' => microtime( true )
3276 * Merge the result of getSessionLagStatus() for several DBs
3277 * using the most pessimistic values to estimate the lag of
3278 * any data derived from them in combination
3280 * This is information is useful for caching modules
3282 * @see WANObjectCache::set()
3283 * @see WANObjectCache::getWithSetCallback()
3285 * @param IDatabase $db1
3286 * @param IDatabase ...
3287 * @return array Map of values:
3288 * - lag: highest lag of any of the DBs or false on error (e.g. replication stopped)
3289 * - since: oldest UNIX timestamp of any of the DB lag estimates
3290 * - pending: whether any of the DBs have uncommitted changes
3293 public static function getCacheSetOptions( IDatabase
$db1 ) {
3294 $res = [ 'lag' => 0, 'since' => INF
, 'pending' => false ];
3295 foreach ( func_get_args() as $db ) {
3296 /** @var IDatabase $db */
3297 $status = $db->getSessionLagStatus();
3298 if ( $status['lag'] === false ) {
3299 $res['lag'] = false;
3300 } elseif ( $res['lag'] !== false ) {
3301 $res['lag'] = max( $res['lag'], $status['lag'] );
3303 $res['since'] = min( $res['since'], $status['since'] );
3304 $res['pending'] = $res['pending'] ?
: $db->writesPending();
3310 public function getLag() {
3314 function maxListLen() {
3318 public function encodeBlob( $b ) {
3322 public function decodeBlob( $b ) {
3323 if ( $b instanceof Blob
) {
3329 public function setSessionOptions( array $options ) {
3333 * Read and execute SQL commands from a file.
3335 * Returns true on success, error string or exception on failure (depending
3336 * on object's error ignore settings).
3338 * @param string $filename File name to open
3339 * @param bool|callable $lineCallback Optional function called before reading each line
3340 * @param bool|callable $resultCallback Optional function called for each MySQL result
3341 * @param bool|string $fname Calling function name or false if name should be
3342 * generated dynamically using $filename
3343 * @param bool|callable $inputCallback Optional function called for each
3344 * complete line sent
3345 * @throws Exception|MWException
3346 * @return bool|string
3348 public function sourceFile(
3349 $filename, $lineCallback = false, $resultCallback = false, $fname = false, $inputCallback = false
3351 MediaWiki\
suppressWarnings();
3352 $fp = fopen( $filename, 'r' );
3353 MediaWiki\restoreWarnings
();
3355 if ( false === $fp ) {
3356 throw new MWException( "Could not open \"{$filename}\".\n" );
3360 $fname = __METHOD__
. "( $filename )";
3364 $error = $this->sourceStream( $fp, $lineCallback, $resultCallback, $fname, $inputCallback );
3365 } catch ( Exception
$e ) {
3376 * Get the full path of a patch file. Originally based on archive()
3377 * from updaters.inc. Keep in mind this always returns a patch, as
3378 * it fails back to MySQL if no DB-specific patch can be found
3380 * @param string $patch The name of the patch, like patch-something.sql
3381 * @return string Full path to patch file
3383 public function patchPath( $patch ) {
3386 $dbType = $this->getType();
3387 if ( file_exists( "$IP/maintenance/$dbType/archives/$patch" ) ) {
3388 return "$IP/maintenance/$dbType/archives/$patch";
3390 return "$IP/maintenance/archives/$patch";
3394 public function setSchemaVars( $vars ) {
3395 $this->mSchemaVars
= $vars;
3399 * Read and execute commands from an open file handle.
3401 * Returns true on success, error string or exception on failure (depending
3402 * on object's error ignore settings).
3404 * @param resource $fp File handle
3405 * @param bool|callable $lineCallback Optional function called before reading each query
3406 * @param bool|callable $resultCallback Optional function called for each MySQL result
3407 * @param string $fname Calling function name
3408 * @param bool|callable $inputCallback Optional function called for each complete query sent
3409 * @return bool|string
3411 public function sourceStream( $fp, $lineCallback = false, $resultCallback = false,
3412 $fname = __METHOD__
, $inputCallback = false
3416 while ( !feof( $fp ) ) {
3417 if ( $lineCallback ) {
3418 call_user_func( $lineCallback );
3421 $line = trim( fgets( $fp ) );
3423 if ( $line == '' ) {
3427 if ( '-' == $line[0] && '-' == $line[1] ) {
3435 $done = $this->streamStatementEnd( $cmd, $line );
3439 if ( $done ||
feof( $fp ) ) {
3440 $cmd = $this->replaceVars( $cmd );
3442 if ( ( $inputCallback && call_user_func( $inputCallback, $cmd ) ) ||
!$inputCallback ) {
3443 $res = $this->query( $cmd, $fname );
3445 if ( $resultCallback ) {
3446 call_user_func( $resultCallback, $res, $this );
3449 if ( false === $res ) {
3450 $err = $this->lastError();
3452 return "Query \"{$cmd}\" failed with error code \"$err\".\n";
3463 * Called by sourceStream() to check if we've reached a statement end
3465 * @param string $sql SQL assembled so far
3466 * @param string $newLine New line about to be added to $sql
3467 * @return bool Whether $newLine contains end of the statement
3469 public function streamStatementEnd( &$sql, &$newLine ) {
3470 if ( $this->delimiter
) {
3472 $newLine = preg_replace( '/' . preg_quote( $this->delimiter
, '/' ) . '$/', '', $newLine );
3473 if ( $newLine != $prev ) {
3482 * Database independent variable replacement. Replaces a set of variables
3483 * in an SQL statement with their contents as given by $this->getSchemaVars().
3485 * Supports '{$var}' `{$var}` and / *$var* / (without the spaces) style variables.
3487 * - '{$var}' should be used for text and is passed through the database's
3489 * - `{$var}` should be used for identifiers (e.g. table and database names).
3490 * It is passed through the database's addIdentifierQuotes method which
3491 * can be overridden if the database uses something other than backticks.
3492 * - / *_* / or / *$wgDBprefix* / passes the name that follows through the
3493 * database's tableName method.
3494 * - / *i* / passes the name that follows through the database's indexName method.
3495 * - In all other cases, / *$var* / is left unencoded. Except for table options,
3496 * its use should be avoided. In 1.24 and older, string encoding was applied.
3498 * @param string $ins SQL statement to replace variables in
3499 * @return string The new SQL statement with variables replaced
3501 protected function replaceVars( $ins ) {
3502 $vars = $this->getSchemaVars();
3503 return preg_replace_callback(
3505 /\* (\$wgDBprefix|[_i]) \*/ (\w*) | # 1-2. tableName, indexName
3506 \'\{\$ (\w+) }\' | # 3. addQuotes
3507 `\{\$ (\w+) }` | # 4. addIdentifierQuotes
3508 /\*\$ (\w+) \*/ # 5. leave unencoded
3510 function ( $m ) use ( $vars ) {
3511 // Note: Because of <https://bugs.php.net/bug.php?id=51881>,
3512 // check for both nonexistent keys *and* the empty string.
3513 if ( isset( $m[1] ) && $m[1] !== '' ) {
3514 if ( $m[1] === 'i' ) {
3515 return $this->indexName( $m[2] );
3517 return $this->tableName( $m[2] );
3519 } elseif ( isset( $m[3] ) && $m[3] !== '' && array_key_exists( $m[3], $vars ) ) {
3520 return $this->addQuotes( $vars[$m[3]] );
3521 } elseif ( isset( $m[4] ) && $m[4] !== '' && array_key_exists( $m[4], $vars ) ) {
3522 return $this->addIdentifierQuotes( $vars[$m[4]] );
3523 } elseif ( isset( $m[5] ) && $m[5] !== '' && array_key_exists( $m[5], $vars ) ) {
3524 return $vars[$m[5]];
3534 * Get schema variables. If none have been set via setSchemaVars(), then
3535 * use some defaults from the current object.
3539 protected function getSchemaVars() {
3540 if ( $this->mSchemaVars
) {
3541 return $this->mSchemaVars
;
3543 return $this->getDefaultSchemaVars();
3548 * Get schema variables to use if none have been set via setSchemaVars().
3550 * Override this in derived classes to provide variables for tables.sql
3551 * and SQL patch files.
3555 protected function getDefaultSchemaVars() {
3559 public function lockIsFree( $lockName, $method ) {
3563 public function lock( $lockName, $method, $timeout = 5 ) {
3564 $this->mNamedLocksHeld
[$lockName] = 1;
3569 public function unlock( $lockName, $method ) {
3570 unset( $this->mNamedLocksHeld
[$lockName] );
3575 public function getScopedLockAndFlush( $lockKey, $fname, $timeout ) {
3576 if ( $this->writesOrCallbacksPending() ) {
3577 // This only flushes transactions to clear snapshots, not to write data
3578 throw new DBUnexpectedError(
3580 "$fname: Cannot COMMIT to clear snapshot because writes are pending."
3584 if ( !$this->lock( $lockKey, $fname, $timeout ) ) {
3588 $unlocker = new ScopedCallback( function () use ( $lockKey, $fname ) {
3589 if ( $this->trxLevel() ) {
3590 // There is a good chance an exception was thrown, causing any early return
3591 // from the caller. Let any error handler get a chance to issue rollback().
3592 // If there isn't one, let the error bubble up and trigger server-side rollback.
3593 $this->onTransactionResolution( function () use ( $lockKey, $fname ) {
3594 $this->unlock( $lockKey, $fname );
3597 $this->unlock( $lockKey, $fname );
3601 $this->commit( __METHOD__
, self
::FLUSHING_INTERNAL
);
3606 public function namedLocksEnqueue() {
3611 * Lock specific tables
3613 * @param array $read Array of tables to lock for read access
3614 * @param array $write Array of tables to lock for write access
3615 * @param string $method Name of caller
3616 * @param bool $lowPriority Whether to indicate writes to be LOW PRIORITY
3619 public function lockTables( $read, $write, $method, $lowPriority = true ) {
3624 * Unlock specific tables
3626 * @param string $method The caller
3629 public function unlockTables( $method ) {
3635 * @param string $tableName
3636 * @param string $fName
3637 * @return bool|ResultWrapper
3640 public function dropTable( $tableName, $fName = __METHOD__
) {
3641 if ( !$this->tableExists( $tableName, $fName ) ) {
3644 $sql = "DROP TABLE " . $this->tableName( $tableName );
3645 if ( $this->cascadingDeletes() ) {
3649 return $this->query( $sql, $fName );
3653 * Get search engine class. All subclasses of this need to implement this
3654 * if they wish to use searching.
3658 public function getSearchEngine() {
3659 return 'SearchEngineDummy';
3662 public function getInfinity() {
3666 public function encodeExpiry( $expiry ) {
3667 return ( $expiry == '' ||
$expiry == 'infinity' ||
$expiry == $this->getInfinity() )
3668 ?
$this->getInfinity()
3669 : $this->timestamp( $expiry );
3672 public function decodeExpiry( $expiry, $format = TS_MW
) {
3673 return ( $expiry == '' ||
$expiry == 'infinity' ||
$expiry == $this->getInfinity() )
3675 : wfTimestamp( $format, $expiry );
3678 public function setBigSelects( $value = true ) {
3682 public function isReadOnly() {
3683 return ( $this->getReadOnlyReason() !== false );
3687 * @return string|bool Reason this DB is read-only or false if it is not
3689 protected function getReadOnlyReason() {
3690 $reason = $this->getLBInfo( 'readOnlyReason' );
3692 return is_string( $reason ) ?
$reason : false;
3699 public function __toString() {
3700 return (string)$this->mConn
;
3704 * Run a few simple sanity checks
3706 public function __destruct() {
3707 if ( $this->mTrxLevel
&& $this->mTrxDoneWrites
) {
3708 trigger_error( "Uncommitted DB writes (transaction from {$this->mTrxFname})." );
3710 $danglingCallbacks = array_merge(
3711 $this->mTrxIdleCallbacks
,
3712 $this->mTrxPreCommitCallbacks
,
3713 $this->mTrxEndCallbacks
3715 if ( $danglingCallbacks ) {
3717 foreach ( $danglingCallbacks as $callbackInfo ) {
3718 $callers[] = $callbackInfo[1];
3720 $callers = implode( ', ', $callers );
3721 trigger_error( "DB transaction callbacks still pending (from $callers)." );
3729 abstract class Database
extends DatabaseBase
{
3730 // B/C until nothing type hints for DatabaseBase
3731 // @TODO: finish renaming DatabaseBase => Database