3 * @defgroup Database Database
5 * This file deals with database interface functions
6 * and query specifics/optimisations.
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License along
19 * with this program; if not, write to the Free Software Foundation, Inc.,
20 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
21 * http://www.gnu.org/copyleft/gpl.html
26 namespace Wikimedia\Rdbms
;
28 use Psr\Log\LoggerAwareInterface
;
29 use Psr\Log\LoggerInterface
;
30 use Psr\Log\NullLogger
;
31 use Wikimedia\ScopedCallback
;
32 use Wikimedia\Timestamp\ConvertibleTimestamp
;
37 use InvalidArgumentException
;
38 use UnexpectedValueException
;
43 * Relational database abstraction object
48 abstract class Database
implements IDatabase
, IMaintainableDatabase
, LoggerAwareInterface
{
49 /** Number of times to re-try an operation in case of deadlock */
50 const DEADLOCK_TRIES
= 4;
51 /** Minimum time to wait before retry, in microseconds */
52 const DEADLOCK_DELAY_MIN
= 500000;
53 /** Maximum time to wait before retry */
54 const DEADLOCK_DELAY_MAX
= 1500000;
56 /** How long before it is worth doing a dummy query to test the connection */
58 const PING_QUERY
= 'SELECT 1 AS ping';
60 const TINY_WRITE_SEC
= 0.010;
61 const SLOW_WRITE_SEC
= 0.500;
62 const SMALL_WRITE_ROWS
= 100;
64 /** @var string Whether lock granularity is on the level of the entire database */
65 const ATTR_DB_LEVEL_LOCKING
= 'db-level-locking';
67 /** @var int New Database instance will not be connected yet when returned */
68 const NEW_UNCONNECTED
= 0;
69 /** @var int New Database instance will already be connected when returned */
70 const NEW_CONNECTED
= 1;
72 /** @var string SQL query */
73 protected $lastQuery = '';
74 /** @var float|bool UNIX timestamp of last write query */
75 protected $lastWriteTime = false;
76 /** @var string|bool */
77 protected $phpError = false;
78 /** @var string Server that this instance is currently connected to */
80 /** @var string User that this instance is currently connected under the name of */
82 /** @var string Password used to establish the current connection */
84 /** @var string Database that this instance is currently connected to */
86 /** @var array[] Map of (table => (dbname, schema, prefix) map) */
87 protected $tableAliases = [];
88 /** @var string[] Map of (index alias => index) */
89 protected $indexAliases = [];
90 /** @var bool Whether this PHP instance is for a CLI script */
92 /** @var string Agent name for query profiling */
94 /** @var array Parameters used by initConnection() to establish a connection */
95 protected $connectionParams = [];
96 /** @var BagOStuff APC cache */
98 /** @var LoggerInterface */
99 protected $connLogger;
100 /** @var LoggerInterface */
101 protected $queryLogger;
102 /** @var callback Error logging callback */
103 protected $errorLogger;
104 /** @var callback Deprecation logging callback */
105 protected $deprecationLogger;
107 /** @var resource|null Database connection */
108 protected $conn = null;
110 protected $opened = false;
112 /** @var array[] List of (callable, method name, atomic section id) */
113 protected $trxIdleCallbacks = [];
114 /** @var array[] List of (callable, method name, atomic section id) */
115 protected $trxPreCommitCallbacks = [];
116 /** @var array[] List of (callable, method name, atomic section id) */
117 protected $trxEndCallbacks = [];
118 /** @var callable[] Map of (name => callable) */
119 protected $trxRecurringCallbacks = [];
120 /** @var bool Whether to suppress triggering of transaction end callbacks */
121 protected $trxEndCallbacksSuppressed = false;
124 protected $tablePrefix = '';
126 protected $schema = '';
130 protected $lbInfo = [];
131 /** @var array|bool */
132 protected $schemaVars = false;
134 protected $sessionVars = [];
135 /** @var array|null */
136 protected $preparedArgs;
137 /** @var string|bool|null Stashed value of html_errors INI setting */
138 protected $htmlErrors;
140 protected $delimiter = ';';
141 /** @var DatabaseDomain */
142 protected $currentDomain;
143 /** @var integer|null Rows affected by the last query to query() or its CRUD wrappers */
144 protected $affectedRowCount;
147 * @var int Transaction status
149 protected $trxStatus = self
::STATUS_TRX_NONE
;
151 * @var Exception|null The last error that caused the status to become STATUS_TRX_ERROR
153 protected $trxStatusCause;
155 * @var array|null If wasKnownStatementRollbackError() prevented trxStatus from being set,
156 * the relevant details are stored here.
158 protected $trxStatusIgnoredCause;
160 * Either 1 if a transaction is active or 0 otherwise.
161 * The other Trx fields may not be meaningfull if this is 0.
165 protected $trxLevel = 0;
167 * Either a short hexidecimal string if a transaction is active or ""
170 * @see Database::trxLevel
172 protected $trxShortId = '';
174 * The UNIX time that the transaction started. Callers can assume that if
175 * snapshot isolation is used, then the data is *at least* up to date to that
176 * point (possibly more up-to-date since the first SELECT defines the snapshot).
179 * @see Database::trxLevel
181 private $trxTimestamp = null;
182 /** @var float Lag estimate at the time of BEGIN */
183 private $trxReplicaLag = null;
185 * Remembers the function name given for starting the most recent transaction via begin().
186 * Used to provide additional context for error reporting.
189 * @see Database::trxLevel
191 private $trxFname = null;
193 * Record if possible write queries were done in the last transaction started
196 * @see Database::trxLevel
198 private $trxDoneWrites = false;
200 * Record if the current transaction was started implicitly due to DBO_TRX being set.
203 * @see Database::trxLevel
205 private $trxAutomatic = false;
207 * Counter for atomic savepoint identifiers. Reset when a new transaction begins.
211 private $trxAtomicCounter = 0;
213 * Array of levels of atomicity within transactions
215 * @var array List of (name, unique ID, savepoint ID)
217 private $trxAtomicLevels = [];
219 * Record if the current transaction was started implicitly by Database::startAtomic
223 private $trxAutomaticAtomic = false;
225 * Track the write query callers of the current transaction
229 private $trxWriteCallers = [];
231 * @var float Seconds spent in write queries for the current transaction
233 private $trxWriteDuration = 0.0;
235 * @var int Number of write queries for the current transaction
237 private $trxWriteQueryCount = 0;
239 * @var int Number of rows affected by write queries for the current transaction
241 private $trxWriteAffectedRows = 0;
243 * @var float Like trxWriteQueryCount but excludes lock-bound, easy to replicate, queries
245 private $trxWriteAdjDuration = 0.0;
247 * @var int Number of write queries counted in trxWriteAdjDuration
249 private $trxWriteAdjQueryCount = 0;
251 * @var float RTT time estimate
253 private $rttEstimate = 0.0;
255 /** @var array Map of (name => 1) for locks obtained via lock() */
256 private $namedLocksHeld = [];
257 /** @var array Map of (table name => 1) for TEMPORARY tables */
258 protected $sessionTempTables = [];
260 /** @var IDatabase|null Lazy handle to the master DB this server replicates from */
261 private $lazyMasterHandle;
263 /** @var float UNIX timestamp */
264 protected $lastPing = 0.0;
266 /** @var int[] Prior flags member variable values */
267 private $priorFlags = [];
269 /** @var object|string Class name or object With profileIn/profileOut methods */
271 /** @var TransactionProfiler */
272 protected $trxProfiler;
275 protected $nonNativeInsertSelectBatchSize = 10000;
277 /** @var string Idiom used when a cancelable atomic section started the transaction */
278 private static $NOT_APPLICABLE = 'n/a';
279 /** @var string Prefix to the atomic section counter used to make savepoint IDs */
280 private static $SAVEPOINT_PREFIX = 'wikimedia_rdbms_atomic';
282 /** @var int Transaction is in a error state requiring a full or savepoint rollback */
283 const STATUS_TRX_ERROR
= 1;
284 /** @var int Transaction is active and in a normal state */
285 const STATUS_TRX_OK
= 2;
286 /** @var int No transaction is active */
287 const STATUS_TRX_NONE
= 3;
290 * @note: exceptions for missing libraries/drivers should be thrown in initConnection()
291 * @param array $params Parameters passed from Database::factory()
293 protected function __construct( array $params ) {
294 foreach ( [ 'host', 'user', 'password', 'dbname' ] as $name ) {
295 $this->connectionParams
[$name] = $params[$name];
298 $this->schema
= $params['schema'];
299 $this->tablePrefix
= $params['tablePrefix'];
301 $this->cliMode
= $params['cliMode'];
302 // Agent name is added to SQL queries in a comment, so make sure it can't break out
303 $this->agent
= str_replace( '/', '-', $params['agent'] );
305 $this->flags
= $params['flags'];
306 if ( $this->flags
& self
::DBO_DEFAULT
) {
307 if ( $this->cliMode
) {
308 $this->flags
&= ~self
::DBO_TRX
;
310 $this->flags |
= self
::DBO_TRX
;
313 // Disregard deprecated DBO_IGNORE flag (T189999)
314 $this->flags
&= ~self
::DBO_IGNORE
;
316 $this->sessionVars
= $params['variables'];
318 $this->srvCache
= $params['srvCache'] ??
new HashBagOStuff();
320 $this->profiler
= $params['profiler'];
321 $this->trxProfiler
= $params['trxProfiler'];
322 $this->connLogger
= $params['connLogger'];
323 $this->queryLogger
= $params['queryLogger'];
324 $this->errorLogger
= $params['errorLogger'];
325 $this->deprecationLogger
= $params['deprecationLogger'];
327 if ( isset( $params['nonNativeInsertSelectBatchSize'] ) ) {
328 $this->nonNativeInsertSelectBatchSize
= $params['nonNativeInsertSelectBatchSize'];
331 // Set initial dummy domain until open() sets the final DB/prefix
332 $this->currentDomain
= DatabaseDomain
::newUnspecified();
336 * Initialize the connection to the database over the wire (or to local files)
338 * @throws LogicException
339 * @throws InvalidArgumentException
340 * @throws DBConnectionError
343 final public function initConnection() {
344 if ( $this->isOpen() ) {
345 throw new LogicException( __METHOD__
. ': already connected.' );
347 // Establish the connection
348 $this->doInitConnection();
349 // Set the domain object after open() sets the relevant fields
350 if ( $this->dbName
!= '' ) {
351 // Domains with server scope but a table prefix are not used by IDatabase classes
352 $this->currentDomain
= new DatabaseDomain( $this->dbName
, null, $this->tablePrefix
);
357 * Actually connect to the database over the wire (or to local files)
359 * @throws InvalidArgumentException
360 * @throws DBConnectionError
363 protected function doInitConnection() {
364 if ( strlen( $this->connectionParams
['user'] ) ) {
366 $this->connectionParams
['host'],
367 $this->connectionParams
['user'],
368 $this->connectionParams
['password'],
369 $this->connectionParams
['dbname']
372 throw new InvalidArgumentException( "No database user provided." );
377 * Construct a Database subclass instance given a database type and parameters
379 * This also connects to the database immediately upon object construction
381 * @param string $dbType A possible DB type (sqlite, mysql, postgres,...)
382 * @param array $p Parameter map with keys:
383 * - host : The hostname of the DB server
384 * - user : The name of the database user the client operates under
385 * - password : The password for the database user
386 * - dbname : The name of the database to use where queries do not specify one.
387 * The database must exist or an error might be thrown. Setting this to the empty string
388 * will avoid any such errors and make the handle have no implicit database scope. This is
389 * useful for queries like SHOW STATUS, CREATE DATABASE, or DROP DATABASE. Note that a
390 * "database" in Postgres is rougly equivalent to an entire MySQL server. This the domain
391 * in which user names and such are defined, e.g. users are database-specific in Postgres.
392 * - schema : The database schema to use (if supported). A "schema" in Postgres is roughly
393 * equivalent to a "database" in MySQL. Note that MySQL and SQLite do not use schemas.
394 * - tablePrefix : Optional table prefix that is implicitly added on to all table names
395 * recognized in queries. This can be used in place of schemas for handle site farms.
396 * - flags : Optional bitfield of DBO_* constants that define connection, protocol,
397 * buffering, and transaction behavior. It is STRONGLY adviced to leave the DBO_DEFAULT
398 * flag in place UNLESS this this database simply acts as a key/value store.
399 * - driver: Optional name of a specific DB client driver. For MySQL, there is only the
400 * 'mysqli' driver; the old one 'mysql' has been removed.
401 * - variables: Optional map of session variables to set after connecting. This can be
402 * used to adjust lock timeouts or encoding modes and the like.
403 * - connLogger: Optional PSR-3 logger interface instance.
404 * - queryLogger: Optional PSR-3 logger interface instance.
405 * - profiler: Optional class name or object with profileIn()/profileOut() methods.
406 * These will be called in query(), using a simplified version of the SQL that also
407 * includes the agent as a SQL comment.
408 * - trxProfiler: Optional TransactionProfiler instance.
409 * - errorLogger: Optional callback that takes an Exception and logs it.
410 * - deprecationLogger: Optional callback that takes a string and logs it.
411 * - cliMode: Whether to consider the execution context that of a CLI script.
412 * - agent: Optional name used to identify the end-user in query profiling/logging.
413 * - srvCache: Optional BagOStuff instance to an APC-style cache.
414 * - nonNativeInsertSelectBatchSize: Optional batch size for non-native INSERT SELECT emulation.
415 * @param int $connect One of the class constants (NEW_CONNECTED, NEW_UNCONNECTED) [optional]
416 * @return Database|null If the database driver or extension cannot be found
417 * @throws InvalidArgumentException If the database driver or extension cannot be found
420 final public static function factory( $dbType, $p = [], $connect = self
::NEW_CONNECTED
) {
421 $class = self
::getClass( $dbType, $p['driver'] ??
null );
423 if ( class_exists( $class ) && is_subclass_of( $class, IDatabase
::class ) ) {
424 // Resolve some defaults for b/c
425 $p['host'] = $p['host'] ??
false;
426 $p['user'] = $p['user'] ??
false;
427 $p['password'] = $p['password'] ??
false;
428 $p['dbname'] = $p['dbname'] ??
false;
429 $p['flags'] = $p['flags'] ??
0;
430 $p['variables'] = $p['variables'] ??
[];
431 $p['tablePrefix'] = $p['tablePrefix'] ??
'';
432 $p['schema'] = $p['schema'] ??
'';
433 $p['cliMode'] = $p['cliMode'] ??
( PHP_SAPI
=== 'cli' || PHP_SAPI
=== 'phpdbg' );
434 $p['agent'] = $p['agent'] ??
'';
435 if ( !isset( $p['connLogger'] ) ) {
436 $p['connLogger'] = new NullLogger();
438 if ( !isset( $p['queryLogger'] ) ) {
439 $p['queryLogger'] = new NullLogger();
441 $p['profiler'] = $p['profiler'] ??
null;
442 if ( !isset( $p['trxProfiler'] ) ) {
443 $p['trxProfiler'] = new TransactionProfiler();
445 if ( !isset( $p['errorLogger'] ) ) {
446 $p['errorLogger'] = function ( Exception
$e ) {
447 trigger_error( get_class( $e ) . ': ' . $e->getMessage(), E_USER_WARNING
);
450 if ( !isset( $p['deprecationLogger'] ) ) {
451 $p['deprecationLogger'] = function ( $msg ) {
452 trigger_error( $msg, E_USER_DEPRECATED
);
456 /** @var Database $conn */
457 $conn = new $class( $p );
458 if ( $connect == self
::NEW_CONNECTED
) {
459 $conn->initConnection();
469 * @param string $dbType A possible DB type (sqlite, mysql, postgres,...)
470 * @param string|null $driver Optional name of a specific DB client driver
471 * @return array Map of (Database::ATTRIBUTE_* constant => value) for all such constants
472 * @throws InvalidArgumentException
475 final public static function attributesFromType( $dbType, $driver = null ) {
476 static $defaults = [ self
::ATTR_DB_LEVEL_LOCKING
=> false ];
478 $class = self
::getClass( $dbType, $driver );
480 return call_user_func( [ $class, 'getAttributes' ] ) +
$defaults;
484 * @param string $dbType A possible DB type (sqlite, mysql, postgres,...)
485 * @param string|null $driver Optional name of a specific DB client driver
486 * @return string Database subclass name to use
487 * @throws InvalidArgumentException
489 private static function getClass( $dbType, $driver = null ) {
490 // For database types with built-in support, the below maps type to IDatabase
491 // implementations. For types with multipe driver implementations (PHP extensions),
492 // an array can be used, keyed by extension name. In case of an array, the
493 // optional 'driver' parameter can be used to force a specific driver. Otherwise,
494 // we auto-detect the first available driver. For types without built-in support,
495 // an class named "Database<Type>" us used, eg. DatabaseFoo for type 'foo'.
496 static $builtinTypes = [
497 'mssql' => DatabaseMssql
::class,
498 'mysql' => [ 'mysqli' => DatabaseMysqli
::class ],
499 'sqlite' => DatabaseSqlite
::class,
500 'postgres' => DatabasePostgres
::class,
503 $dbType = strtolower( $dbType );
506 if ( isset( $builtinTypes[$dbType] ) ) {
507 $possibleDrivers = $builtinTypes[$dbType];
508 if ( is_string( $possibleDrivers ) ) {
509 $class = $possibleDrivers;
511 if ( (string)$driver !== '' ) {
512 if ( !isset( $possibleDrivers[$driver] ) ) {
513 throw new InvalidArgumentException( __METHOD__
.
514 " type '$dbType' does not support driver '{$driver}'" );
516 $class = $possibleDrivers[$driver];
519 foreach ( $possibleDrivers as $posDriver => $possibleClass ) {
520 if ( extension_loaded( $posDriver ) ) {
521 $class = $possibleClass;
528 $class = 'Database' . ucfirst( $dbType );
531 if ( $class === false ) {
532 throw new InvalidArgumentException( __METHOD__
.
533 " no viable database extension found for type '$dbType'" );
540 * @return array Map of (Database::ATTRIBUTE_* constant => value
543 protected static function getAttributes() {
548 * Set the PSR-3 logger interface to use for query logging. (The logger
549 * interfaces for connection logging and error logging can be set with the
552 * @param LoggerInterface $logger
554 public function setLogger( LoggerInterface
$logger ) {
555 $this->queryLogger
= $logger;
558 public function getServerInfo() {
559 return $this->getServerVersion();
562 public function bufferResults( $buffer = null ) {
563 $res = !$this->getFlag( self
::DBO_NOBUFFER
);
564 if ( $buffer !== null ) {
566 ?
$this->clearFlag( self
::DBO_NOBUFFER
)
567 : $this->setFlag( self
::DBO_NOBUFFER
);
573 public function trxLevel() {
574 return $this->trxLevel
;
577 public function trxTimestamp() {
578 return $this->trxLevel ?
$this->trxTimestamp
: null;
582 * @return int One of the STATUS_TRX_* class constants
585 public function trxStatus() {
586 return $this->trxStatus
;
589 public function tablePrefix( $prefix = null ) {
590 $old = $this->tablePrefix
;
591 if ( $prefix !== null ) {
592 $this->tablePrefix
= $prefix;
593 $this->currentDomain
= ( $this->dbName
!= '' )
594 ?
new DatabaseDomain( $this->dbName
, null, $this->tablePrefix
)
595 : DatabaseDomain
::newUnspecified();
601 public function dbSchema( $schema = null ) {
602 $old = $this->schema
;
603 if ( $schema !== null ) {
604 $this->schema
= $schema;
610 public function getLBInfo( $name = null ) {
611 if ( is_null( $name ) ) {
612 return $this->lbInfo
;
614 if ( array_key_exists( $name, $this->lbInfo
) ) {
615 return $this->lbInfo
[$name];
622 public function setLBInfo( $name, $value = null ) {
623 if ( is_null( $value ) ) {
624 $this->lbInfo
= $name;
626 $this->lbInfo
[$name] = $value;
630 public function setLazyMasterHandle( IDatabase
$conn ) {
631 $this->lazyMasterHandle
= $conn;
635 * @return IDatabase|null
636 * @see setLazyMasterHandle()
639 protected function getLazyMasterHandle() {
640 return $this->lazyMasterHandle
;
643 public function implicitGroupby() {
647 public function implicitOrderby() {
651 public function lastQuery() {
652 return $this->lastQuery
;
655 public function doneWrites() {
656 return (bool)$this->lastWriteTime
;
659 public function lastDoneWrites() {
660 return $this->lastWriteTime ?
: false;
663 public function writesPending() {
664 return $this->trxLevel
&& $this->trxDoneWrites
;
667 public function writesOrCallbacksPending() {
668 return $this->trxLevel
&& (
669 $this->trxDoneWrites ||
670 $this->trxIdleCallbacks ||
671 $this->trxPreCommitCallbacks ||
672 $this->trxEndCallbacks
676 public function preCommitCallbacksPending() {
677 return $this->trxLevel
&& $this->trxPreCommitCallbacks
;
681 * @return string|null
683 final protected function getTransactionRoundId() {
684 // If transaction round participation is enabled, see if one is active
685 if ( $this->getFlag( self
::DBO_TRX
) ) {
686 $id = $this->getLBInfo( 'trxRoundId' );
688 return is_string( $id ) ?
$id : null;
694 public function pendingWriteQueryDuration( $type = self
::ESTIMATE_TOTAL
) {
695 if ( !$this->trxLevel
) {
697 } elseif ( !$this->trxDoneWrites
) {
702 case self
::ESTIMATE_DB_APPLY
:
704 $rttAdjTotal = $this->trxWriteAdjQueryCount
* $rtt;
705 $applyTime = max( $this->trxWriteAdjDuration
- $rttAdjTotal, 0 );
706 // For omitted queries, make them count as something at least
707 $omitted = $this->trxWriteQueryCount
- $this->trxWriteAdjQueryCount
;
708 $applyTime +
= self
::TINY_WRITE_SEC
* $omitted;
711 default: // everything
712 return $this->trxWriteDuration
;
716 public function pendingWriteCallers() {
717 return $this->trxLevel ?
$this->trxWriteCallers
: [];
720 public function pendingWriteRowsAffected() {
721 return $this->trxWriteAffectedRows
;
725 * List the methods that have write queries or callbacks for the current transaction
727 * This method should not be used outside of Database/LoadBalancer
732 public function pendingWriteAndCallbackCallers() {
733 $fnames = $this->pendingWriteCallers();
735 $this->trxIdleCallbacks
,
736 $this->trxPreCommitCallbacks
,
737 $this->trxEndCallbacks
739 foreach ( $callbacks as $callback ) {
740 $fnames[] = $callback[1];
750 private function flatAtomicSectionList() {
751 return array_reduce( $this->trxAtomicLevels
, function ( $accum, $v ) {
752 return $accum === null ?
$v[0] : "$accum, " . $v[0];
756 public function isOpen() {
757 return $this->opened
;
760 public function setFlag( $flag, $remember = self
::REMEMBER_NOTHING
) {
761 if ( ( $flag & self
::DBO_IGNORE
) ) {
762 throw new UnexpectedValueException( "Modifying DBO_IGNORE is not allowed." );
765 if ( $remember === self
::REMEMBER_PRIOR
) {
766 array_push( $this->priorFlags
, $this->flags
);
768 $this->flags |
= $flag;
771 public function clearFlag( $flag, $remember = self
::REMEMBER_NOTHING
) {
772 if ( ( $flag & self
::DBO_IGNORE
) ) {
773 throw new UnexpectedValueException( "Modifying DBO_IGNORE is not allowed." );
776 if ( $remember === self
::REMEMBER_PRIOR
) {
777 array_push( $this->priorFlags
, $this->flags
);
779 $this->flags
&= ~
$flag;
782 public function restoreFlags( $state = self
::RESTORE_PRIOR
) {
783 if ( !$this->priorFlags
) {
787 if ( $state === self
::RESTORE_INITIAL
) {
788 $this->flags
= reset( $this->priorFlags
);
789 $this->priorFlags
= [];
791 $this->flags
= array_pop( $this->priorFlags
);
795 public function getFlag( $flag ) {
796 return !!( $this->flags
& $flag );
800 * @param string $name Class field name
802 * @deprecated Since 1.28
804 public function getProperty( $name ) {
808 public function getDomainID() {
809 return $this->currentDomain
->getId();
812 final public function getWikiID() {
813 return $this->getDomainID();
817 * Get information about an index into an object
818 * @param string $table Table name
819 * @param string $index Index name
820 * @param string $fname Calling function name
821 * @return mixed Database-specific index description class or false if the index does not exist
823 abstract function indexInfo( $table, $index, $fname = __METHOD__
);
826 * Wrapper for addslashes()
828 * @param string $s String to be slashed.
829 * @return string Slashed string.
831 abstract function strencode( $s );
834 * Set a custom error handler for logging errors during database connection
836 protected function installErrorHandler() {
837 $this->phpError
= false;
838 $this->htmlErrors
= ini_set( 'html_errors', '0' );
839 set_error_handler( [ $this, 'connectionErrorLogger' ] );
843 * Restore the previous error handler and return the last PHP error for this DB
845 * @return bool|string
847 protected function restoreErrorHandler() {
848 restore_error_handler();
849 if ( $this->htmlErrors
!== false ) {
850 ini_set( 'html_errors', $this->htmlErrors
);
853 return $this->getLastPHPError();
857 * @return string|bool Last PHP error for this DB (typically connection errors)
859 protected function getLastPHPError() {
860 if ( $this->phpError
) {
861 $error = preg_replace( '!\[<a.*</a>\]!', '', $this->phpError
);
862 $error = preg_replace( '!^.*?:\s?(.*)$!', '$1', $error );
871 * Error handler for logging errors during database connection
872 * This method should not be used outside of Database classes
875 * @param string $errstr
877 public function connectionErrorLogger( $errno, $errstr ) {
878 $this->phpError
= $errstr;
882 * Create a log context to pass to PSR-3 logger functions.
884 * @param array $extras Additional data to add to context
887 protected function getLogContext( array $extras = [] ) {
890 'db_server' => $this->server
,
891 'db_name' => $this->dbName
,
892 'db_user' => $this->user
,
898 final public function close() {
899 $exception = null; // error to throw after disconnecting
902 // Resolve any dangling transaction first
903 if ( $this->trxLevel
) {
904 if ( $this->trxAtomicLevels
) {
905 // Cannot let incomplete atomic sections be committed
906 $levels = $this->flatAtomicSectionList();
907 $exception = new DBUnexpectedError(
909 __METHOD__
. ": atomic sections $levels are still open."
911 } elseif ( $this->trxAutomatic
) {
912 // Only the connection manager can commit non-empty DBO_TRX transactions
913 if ( $this->writesOrCallbacksPending() ) {
914 $exception = new DBUnexpectedError(
917 ": mass commit/rollback of peer transaction required (DBO_TRX set)."
920 } elseif ( $this->trxLevel
) {
921 // Commit explicit transactions as if this was commit()
922 $this->queryLogger
->warning(
923 __METHOD__
. ": writes or callbacks still pending.",
924 [ 'trace' => ( new RuntimeException() )->getTraceAsString() ]
928 if ( $this->trxEndCallbacksSuppressed
) {
929 $exception = $exception ?
: new DBUnexpectedError(
931 __METHOD__
. ': callbacks are suppressed; cannot properly commit.'
935 // Commit or rollback the changes and run any callbacks as needed
936 if ( $this->trxStatus
=== self
::STATUS_TRX_OK
&& !$exception ) {
939 $this->trxAutomatic ? self
::FLUSHING_INTERNAL
: self
::FLUSHING_ONE
942 $this->rollback( __METHOD__
, self
::FLUSHING_INTERNAL
);
946 // Close the actual connection in the binding handle
947 $closed = $this->closeConnection();
950 $closed = true; // already closed; nothing to do
953 $this->opened
= false;
955 // Throw any unexpected errors after having disconnected
956 if ( $exception instanceof Exception
) {
960 // Sanity check that no callbacks are dangling
961 $fnames = $this->pendingWriteAndCallbackCallers();
963 throw new RuntimeException(
964 "Transaction callbacks are still pending:\n" . implode( ', ', $fnames )
972 * Make sure isOpen() returns true as a sanity check
974 * @throws DBUnexpectedError
976 protected function assertOpen() {
977 if ( !$this->isOpen() ) {
978 throw new DBUnexpectedError( $this, "DB connection was already closed." );
983 * Closes underlying database connection
985 * @return bool Whether connection was closed successfully
987 abstract protected function closeConnection();
990 * @deprecated since 1.32
991 * @param string $error Fallback message, if none is given by DB
992 * @throws DBConnectionError
994 public function reportConnectionError( $error = 'Unknown error' ) {
995 call_user_func( $this->deprecationLogger
, 'Use of ' . __METHOD__
. ' is deprecated.' );
996 throw new DBConnectionError( $this, $this->lastError() ?
: $error );
1000 * Run a query and return a DBMS-dependent wrapper (that has all IResultWrapper methods)
1002 * This might return things, such as mysqli_result, that do not formally implement
1003 * IResultWrapper, but nonetheless implement all of its methods correctly
1005 * @param string $sql SQL query.
1006 * @return IResultWrapper|bool Iterator to feed to fetchObject/fetchRow; false on failure
1008 abstract protected function doQuery( $sql );
1011 * Determine whether a query writes to the DB.
1012 * Should return true if unsure.
1014 * @param string $sql
1017 protected function isWriteQuery( $sql ) {
1019 '/^(?:SELECT|BEGIN|ROLLBACK|COMMIT|SET|SHOW|EXPLAIN|\(SELECT)\b/i', $sql );
1023 * @param string $sql
1024 * @return string|null
1026 protected function getQueryVerb( $sql ) {
1027 return preg_match( '/^\s*([a-z]+)/i', $sql, $m ) ?
strtoupper( $m[1] ) : null;
1031 * Determine whether a SQL statement is sensitive to isolation level.
1032 * A SQL statement is considered transactable if its result could vary
1033 * depending on the transaction isolation level. Operational commands
1034 * such as 'SET' and 'SHOW' are not considered to be transactable.
1036 * @param string $sql
1039 protected function isTransactableQuery( $sql ) {
1041 $this->getQueryVerb( $sql ),
1042 [ 'BEGIN', 'COMMIT', 'ROLLBACK', 'SHOW', 'SET', 'CREATE', 'ALTER' ],
1048 * @param string $sql A SQL query
1049 * @return bool Whether $sql is SQL for TEMPORARY table operation
1051 protected function registerTempTableOperation( $sql ) {
1053 '/^CREATE\s+TEMPORARY\s+TABLE\s+(?:IF\s+NOT\s+EXISTS\s+)?[`"\']?(\w+)[`"\']?/i',
1057 $this->sessionTempTables
[$matches[1]] = 1;
1060 } elseif ( preg_match(
1061 '/^DROP\s+(?:TEMPORARY\s+)?TABLE\s+(?:IF\s+EXISTS\s+)?[`"\']?(\w+)[`"\']?/i',
1065 $isTemp = isset( $this->sessionTempTables
[$matches[1]] );
1066 unset( $this->sessionTempTables
[$matches[1]] );
1069 } elseif ( preg_match(
1070 '/^TRUNCATE\s+(?:TEMPORARY\s+)?TABLE\s+(?:IF\s+EXISTS\s+)?[`"\']?(\w+)[`"\']?/i',
1074 return isset( $this->sessionTempTables
[$matches[1]] );
1075 } elseif ( preg_match(
1076 '/^(?:INSERT\s+(?:\w+\s+)?INTO|UPDATE|DELETE\s+FROM)\s+[`"\']?(\w+)[`"\']?/i',
1080 return isset( $this->sessionTempTables
[$matches[1]] );
1086 public function query( $sql, $fname = __METHOD__
, $tempIgnore = false ) {
1087 $this->assertTransactionStatus( $sql, $fname );
1089 # Avoid fatals if close() was called
1090 $this->assertOpen();
1092 $priorWritesPending = $this->writesOrCallbacksPending();
1093 $this->lastQuery
= $sql;
1095 $isWrite = $this->isWriteQuery( $sql );
1097 $isNonTempWrite = !$this->registerTempTableOperation( $sql );
1099 $isNonTempWrite = false;
1103 if ( $this->getLBInfo( 'replica' ) === true ) {
1106 'Write operations are not allowed on replica database connections.'
1109 # In theory, non-persistent writes are allowed in read-only mode, but due to things
1110 # like https://bugs.mysql.com/bug.php?id=33669 that might not work anyway...
1111 $reason = $this->getReadOnlyReason();
1112 if ( $reason !== false ) {
1113 throw new DBReadOnlyError( $this, "Database is read-only: $reason" );
1115 # Set a flag indicating that writes have been done
1116 $this->lastWriteTime
= microtime( true );
1119 # Add trace comment to the begin of the sql string, right after the operator.
1120 # Or, for one-word queries (like "BEGIN" or COMMIT") add it to the end (T44598)
1121 $commentedSql = preg_replace( '/\s|$/', " /* $fname {$this->agent} */ ", $sql, 1 );
1123 # Start implicit transactions that wrap the request if DBO_TRX is enabled
1124 if ( !$this->trxLevel
&& $this->getFlag( self
::DBO_TRX
)
1125 && $this->isTransactableQuery( $sql )
1127 $this->begin( __METHOD__
. " ($fname)", self
::TRANSACTION_INTERNAL
);
1128 $this->trxAutomatic
= true;
1131 # Keep track of whether the transaction has write queries pending
1132 if ( $this->trxLevel
&& !$this->trxDoneWrites
&& $isWrite ) {
1133 $this->trxDoneWrites
= true;
1134 $this->trxProfiler
->transactionWritingIn(
1135 $this->server
, $this->dbName
, $this->trxShortId
);
1138 if ( $this->getFlag( self
::DBO_DEBUG
) ) {
1139 $this->queryLogger
->debug( "{$this->dbName} {$commentedSql}" );
1142 # Send the query to the server and fetch any corresponding errors
1143 $ret = $this->doProfiledQuery( $sql, $commentedSql, $isNonTempWrite, $fname );
1144 $lastError = $this->lastError();
1145 $lastErrno = $this->lastErrno();
1147 # Try reconnecting if the connection was lost
1148 if ( $ret === false && $this->wasConnectionLoss() ) {
1149 # Check if any meaningful session state was lost
1150 $recoverable = $this->canRecoverFromDisconnect( $sql, $priorWritesPending );
1151 # Update session state tracking and try to restore the connection
1152 $reconnected = $this->replaceLostConnection( __METHOD__
);
1153 # Silently resend the query to the server if it is safe and possible
1154 if ( $reconnected && $recoverable ) {
1155 $ret = $this->doProfiledQuery( $sql, $commentedSql, $isNonTempWrite, $fname );
1156 $lastError = $this->lastError();
1157 $lastErrno = $this->lastErrno();
1159 if ( $ret === false && $this->wasConnectionLoss() ) {
1160 # Query probably causes disconnects; reconnect and do not re-run it
1161 $this->replaceLostConnection( __METHOD__
);
1166 if ( $ret === false ) {
1167 if ( $this->trxLevel
) {
1168 if ( $this->wasKnownStatementRollbackError() ) {
1169 # We're ignoring an error that caused just the current query to be aborted.
1170 # But log the cause so we can log a deprecation notice if a caller actually
1172 $this->trxStatusIgnoredCause
= [ $lastError, $lastErrno, $fname ];
1174 # Either the query was aborted or all queries after BEGIN where aborted.
1175 # In the first case, the only options going forward are (a) ROLLBACK, or
1176 # (b) ROLLBACK TO SAVEPOINT (if one was set). If the later case, the only
1177 # option is ROLLBACK, since the snapshots would have been released.
1178 $this->trxStatus
= self
::STATUS_TRX_ERROR
;
1179 $this->trxStatusCause
=
1180 $this->makeQueryException( $lastError, $lastErrno, $sql, $fname );
1181 $tempIgnore = false; // cannot recover
1182 $this->trxStatusIgnoredCause
= null;
1186 $this->reportQueryError( $lastError, $lastErrno, $sql, $fname, $tempIgnore );
1189 return $this->resultObject( $ret );
1193 * Wrapper for query() that also handles profiling, logging, and affected row count updates
1195 * @param string $sql Original SQL query
1196 * @param string $commentedSql SQL query with debugging/trace comment
1197 * @param bool $isWrite Whether the query is a (non-temporary) write operation
1198 * @param string $fname Name of the calling function
1199 * @return bool|ResultWrapper True for a successful write query, ResultWrapper
1200 * object for a successful read query, or false on failure
1202 private function doProfiledQuery( $sql, $commentedSql, $isWrite, $fname ) {
1203 $isMaster = !is_null( $this->getLBInfo( 'master' ) );
1204 # generalizeSQL() will probably cut down the query to reasonable
1205 # logging size most of the time. The substr is really just a sanity check.
1207 $queryProf = 'query-m: ' . substr( self
::generalizeSQL( $sql ), 0, 255 );
1209 $queryProf = 'query: ' . substr( self
::generalizeSQL( $sql ), 0, 255 );
1212 # Include query transaction state
1213 $queryProf .= $this->trxShortId ?
" [TRX#{$this->trxShortId}]" : "";
1215 $startTime = microtime( true );
1216 if ( $this->profiler
) {
1217 $this->profiler
->profileIn( $queryProf );
1219 $this->affectedRowCount
= null;
1220 $ret = $this->doQuery( $commentedSql );
1221 $this->affectedRowCount
= $this->affectedRows();
1222 if ( $this->profiler
) {
1223 $this->profiler
->profileOut( $queryProf );
1225 $queryRuntime = max( microtime( true ) - $startTime, 0.0 );
1227 unset( $queryProfSection ); // profile out (if set)
1229 if ( $ret !== false ) {
1230 $this->lastPing
= $startTime;
1231 if ( $isWrite && $this->trxLevel
) {
1232 $this->updateTrxWriteQueryTime( $sql, $queryRuntime, $this->affectedRows() );
1233 $this->trxWriteCallers
[] = $fname;
1237 if ( $sql === self
::PING_QUERY
) {
1238 $this->rttEstimate
= $queryRuntime;
1241 $this->trxProfiler
->recordQueryCompletion(
1242 $queryProf, $startTime, $isWrite, $this->affectedRows()
1244 $this->queryLogger
->debug( $sql, [
1246 'master' => $isMaster,
1247 'runtime' => $queryRuntime,
1254 * Update the estimated run-time of a query, not counting large row lock times
1256 * LoadBalancer can be set to rollback transactions that will create huge replication
1257 * lag. It bases this estimate off of pendingWriteQueryDuration(). Certain simple
1258 * queries, like inserting a row can take a long time due to row locking. This method
1259 * uses some simple heuristics to discount those cases.
1261 * @param string $sql A SQL write query
1262 * @param float $runtime Total runtime, including RTT
1263 * @param int $affected Affected row count
1265 private function updateTrxWriteQueryTime( $sql, $runtime, $affected ) {
1266 // Whether this is indicative of replica DB runtime (except for RBR or ws_repl)
1267 $indicativeOfReplicaRuntime = true;
1268 if ( $runtime > self
::SLOW_WRITE_SEC
) {
1269 $verb = $this->getQueryVerb( $sql );
1270 // insert(), upsert(), replace() are fast unless bulky in size or blocked on locks
1271 if ( $verb === 'INSERT' ) {
1272 $indicativeOfReplicaRuntime = $this->affectedRows() > self
::SMALL_WRITE_ROWS
;
1273 } elseif ( $verb === 'REPLACE' ) {
1274 $indicativeOfReplicaRuntime = $this->affectedRows() > self
::SMALL_WRITE_ROWS
/ 2;
1278 $this->trxWriteDuration +
= $runtime;
1279 $this->trxWriteQueryCount +
= 1;
1280 $this->trxWriteAffectedRows +
= $affected;
1281 if ( $indicativeOfReplicaRuntime ) {
1282 $this->trxWriteAdjDuration +
= $runtime;
1283 $this->trxWriteAdjQueryCount +
= 1;
1288 * @param string $sql
1289 * @param string $fname
1290 * @throws DBTransactionStateError
1292 private function assertTransactionStatus( $sql, $fname ) {
1293 if ( $this->getQueryVerb( $sql ) === 'ROLLBACK' ) { // transaction/savepoint
1297 if ( $this->trxStatus
< self
::STATUS_TRX_OK
) {
1298 throw new DBTransactionStateError(
1300 "Cannot execute query from $fname while transaction status is ERROR.",
1302 $this->trxStatusCause
1304 } elseif ( $this->trxStatus
=== self
::STATUS_TRX_OK
&& $this->trxStatusIgnoredCause
) {
1305 list( $iLastError, $iLastErrno, $iFname ) = $this->trxStatusIgnoredCause
;
1306 call_user_func( $this->deprecationLogger
,
1307 "Caller from $fname ignored an error originally raised from $iFname: " .
1308 "[$iLastErrno] $iLastError"
1310 $this->trxStatusIgnoredCause
= null;
1315 * Determine whether or not it is safe to retry queries after a database
1316 * connection is lost
1318 * @param string $sql SQL query
1319 * @param bool $priorWritesPending Whether there is a transaction open with
1320 * possible write queries or transaction pre-commit/idle callbacks
1321 * waiting on it to finish.
1322 * @return bool True if it is safe to retry the query, false otherwise
1324 private function canRecoverFromDisconnect( $sql, $priorWritesPending ) {
1325 # Transaction dropped; this can mean lost writes, or REPEATABLE-READ snapshots.
1326 # Dropped connections also mean that named locks are automatically released.
1327 # Only allow error suppression in autocommit mode or when the lost transaction
1328 # didn't matter anyway (aside from DBO_TRX snapshot loss).
1329 if ( $this->namedLocksHeld
) {
1330 return false; // possible critical section violation
1331 } elseif ( $this->sessionTempTables
) {
1332 return false; // tables might be queried latter
1333 } elseif ( $sql === 'COMMIT' ) {
1334 return !$priorWritesPending; // nothing written anyway? (T127428)
1335 } elseif ( $sql === 'ROLLBACK' ) {
1336 return true; // transaction lost...which is also what was requested :)
1337 } elseif ( $this->explicitTrxActive() ) {
1338 return false; // don't drop atomocity and explicit snapshots
1339 } elseif ( $priorWritesPending ) {
1340 return false; // prior writes lost from implicit transaction
1347 * Clean things up after session (and thus transaction) loss
1349 private function handleSessionLoss() {
1350 // Clean up tracking of session-level things...
1351 // https://dev.mysql.com/doc/refman/5.7/en/implicit-commit.html
1352 // https://www.postgresql.org/docs/9.2/static/sql-createtable.html (ignoring ON COMMIT)
1353 $this->sessionTempTables
= [];
1354 // https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_get-lock
1355 // https://www.postgresql.org/docs/9.4/static/functions-admin.html#FUNCTIONS-ADVISORY-LOCKS
1356 $this->namedLocksHeld
= [];
1357 // Session loss implies transaction loss
1358 $this->handleTransactionLoss();
1362 * Clean things up after transaction loss
1364 private function handleTransactionLoss() {
1365 $this->trxLevel
= 0;
1366 $this->trxAtomicCounter
= 0;
1367 $this->trxIdleCallbacks
= []; // T67263; transaction already lost
1368 $this->trxPreCommitCallbacks
= []; // T67263; transaction already lost
1370 // Handle callbacks in trxEndCallbacks, e.g. onTransactionResolution().
1371 // If callback suppression is set then the array will remain unhandled.
1372 $this->runOnTransactionIdleCallbacks( self
::TRIGGER_ROLLBACK
);
1373 } catch ( Exception
$ex ) {
1374 // Already logged; move on...
1377 // Handle callbacks in trxRecurringCallbacks, e.g. setTransactionListener()
1378 $this->runTransactionListenerCallbacks( self
::TRIGGER_ROLLBACK
);
1379 } catch ( Exception
$ex ) {
1380 // Already logged; move on...
1385 * Checks whether the cause of the error is detected to be a timeout.
1387 * It returns false by default, and not all engines support detecting this yet.
1388 * If this returns false, it will be treated as a generic query error.
1390 * @param string $error Error text
1391 * @param int $errno Error number
1394 protected function wasQueryTimeout( $error, $errno ) {
1399 * Report a query error. Log the error, and if neither the object ignore
1400 * flag nor the $tempIgnore flag is set, throw a DBQueryError.
1402 * @param string $error
1404 * @param string $sql
1405 * @param string $fname
1406 * @param bool $tempIgnore
1407 * @throws DBQueryError
1409 public function reportQueryError( $error, $errno, $sql, $fname, $tempIgnore = false ) {
1410 if ( $tempIgnore ) {
1411 $this->queryLogger
->debug( "SQL ERROR (ignored): $error\n" );
1413 $exception = $this->makeQueryException( $error, $errno, $sql, $fname );
1420 * @param string $error
1421 * @param string|int $errno
1422 * @param string $sql
1423 * @param string $fname
1426 private function makeQueryException( $error, $errno, $sql, $fname ) {
1427 $sql1line = mb_substr( str_replace( "\n", "\\n", $sql ), 0, 5 * 1024 );
1428 $this->queryLogger
->error(
1429 "{fname}\t{db_server}\t{errno}\t{error}\t{sql1line}",
1430 $this->getLogContext( [
1431 'method' => __METHOD__
,
1434 'sql1line' => $sql1line,
1438 $this->queryLogger
->debug( "SQL ERROR: " . $error . "\n" );
1439 $wasQueryTimeout = $this->wasQueryTimeout( $error, $errno );
1440 if ( $wasQueryTimeout ) {
1441 $e = new DBQueryTimeoutError( $this, $error, $errno, $sql, $fname );
1443 $e = new DBQueryError( $this, $error, $errno, $sql, $fname );
1449 public function freeResult( $res ) {
1452 public function selectField(
1453 $table, $var, $cond = '', $fname = __METHOD__
, $options = [], $join_conds = []
1455 if ( $var === '*' ) { // sanity
1456 throw new DBUnexpectedError( $this, "Cannot use a * field: got '$var'" );
1459 if ( !is_array( $options ) ) {
1460 $options = [ $options ];
1463 $options['LIMIT'] = 1;
1465 $res = $this->select( $table, $var, $cond, $fname, $options, $join_conds );
1466 if ( $res === false ||
!$this->numRows( $res ) ) {
1470 $row = $this->fetchRow( $res );
1472 if ( $row !== false ) {
1473 return reset( $row );
1479 public function selectFieldValues(
1480 $table, $var, $cond = '', $fname = __METHOD__
, $options = [], $join_conds = []
1482 if ( $var === '*' ) { // sanity
1483 throw new DBUnexpectedError( $this, "Cannot use a * field" );
1484 } elseif ( !is_string( $var ) ) { // sanity
1485 throw new DBUnexpectedError( $this, "Cannot use an array of fields" );
1488 if ( !is_array( $options ) ) {
1489 $options = [ $options ];
1492 $res = $this->select( $table, $var, $cond, $fname, $options, $join_conds );
1493 if ( $res === false ) {
1498 foreach ( $res as $row ) {
1499 $values[] = $row->$var;
1506 * Returns an optional USE INDEX clause to go after the table, and a
1507 * string to go at the end of the query.
1509 * @param array $options Associative array of options to be turned into
1510 * an SQL query, valid keys are listed in the function.
1512 * @see Database::select()
1514 protected function makeSelectOptions( $options ) {
1515 $preLimitTail = $postLimitTail = '';
1520 foreach ( $options as $key => $option ) {
1521 if ( is_numeric( $key ) ) {
1522 $noKeyOptions[$option] = true;
1526 $preLimitTail .= $this->makeGroupByWithHaving( $options );
1528 $preLimitTail .= $this->makeOrderBy( $options );
1530 if ( isset( $noKeyOptions['FOR UPDATE'] ) ) {
1531 $postLimitTail .= ' FOR UPDATE';
1534 if ( isset( $noKeyOptions['LOCK IN SHARE MODE'] ) ) {
1535 $postLimitTail .= ' LOCK IN SHARE MODE';
1538 if ( isset( $noKeyOptions['DISTINCT'] ) ||
isset( $noKeyOptions['DISTINCTROW'] ) ) {
1539 $startOpts .= 'DISTINCT';
1542 # Various MySQL extensions
1543 if ( isset( $noKeyOptions['STRAIGHT_JOIN'] ) ) {
1544 $startOpts .= ' /*! STRAIGHT_JOIN */';
1547 if ( isset( $noKeyOptions['HIGH_PRIORITY'] ) ) {
1548 $startOpts .= ' HIGH_PRIORITY';
1551 if ( isset( $noKeyOptions['SQL_BIG_RESULT'] ) ) {
1552 $startOpts .= ' SQL_BIG_RESULT';
1555 if ( isset( $noKeyOptions['SQL_BUFFER_RESULT'] ) ) {
1556 $startOpts .= ' SQL_BUFFER_RESULT';
1559 if ( isset( $noKeyOptions['SQL_SMALL_RESULT'] ) ) {
1560 $startOpts .= ' SQL_SMALL_RESULT';
1563 if ( isset( $noKeyOptions['SQL_CALC_FOUND_ROWS'] ) ) {
1564 $startOpts .= ' SQL_CALC_FOUND_ROWS';
1567 if ( isset( $noKeyOptions['SQL_CACHE'] ) ) {
1568 $startOpts .= ' SQL_CACHE';
1571 if ( isset( $noKeyOptions['SQL_NO_CACHE'] ) ) {
1572 $startOpts .= ' SQL_NO_CACHE';
1575 if ( isset( $options['USE INDEX'] ) && is_string( $options['USE INDEX'] ) ) {
1576 $useIndex = $this->useIndexClause( $options['USE INDEX'] );
1580 if ( isset( $options['IGNORE INDEX'] ) && is_string( $options['IGNORE INDEX'] ) ) {
1581 $ignoreIndex = $this->ignoreIndexClause( $options['IGNORE INDEX'] );
1586 return [ $startOpts, $useIndex, $preLimitTail, $postLimitTail, $ignoreIndex ];
1590 * Returns an optional GROUP BY with an optional HAVING
1592 * @param array $options Associative array of options
1594 * @see Database::select()
1597 protected function makeGroupByWithHaving( $options ) {
1599 if ( isset( $options['GROUP BY'] ) ) {
1600 $gb = is_array( $options['GROUP BY'] )
1601 ?
implode( ',', $options['GROUP BY'] )
1602 : $options['GROUP BY'];
1603 $sql .= ' GROUP BY ' . $gb;
1605 if ( isset( $options['HAVING'] ) ) {
1606 $having = is_array( $options['HAVING'] )
1607 ?
$this->makeList( $options['HAVING'], self
::LIST_AND
)
1608 : $options['HAVING'];
1609 $sql .= ' HAVING ' . $having;
1616 * Returns an optional ORDER BY
1618 * @param array $options Associative array of options
1620 * @see Database::select()
1623 protected function makeOrderBy( $options ) {
1624 if ( isset( $options['ORDER BY'] ) ) {
1625 $ob = is_array( $options['ORDER BY'] )
1626 ?
implode( ',', $options['ORDER BY'] )
1627 : $options['ORDER BY'];
1629 return ' ORDER BY ' . $ob;
1635 public function select(
1636 $table, $vars, $conds = '', $fname = __METHOD__
, $options = [], $join_conds = []
1638 $sql = $this->selectSQLText( $table, $vars, $conds, $fname, $options, $join_conds );
1640 return $this->query( $sql, $fname );
1643 public function selectSQLText( $table, $vars, $conds = '', $fname = __METHOD__
,
1644 $options = [], $join_conds = []
1646 if ( is_array( $vars ) ) {
1647 $fields = implode( ',', $this->fieldNamesWithAlias( $vars ) );
1652 $options = (array)$options;
1653 $useIndexes = ( isset( $options['USE INDEX'] ) && is_array( $options['USE INDEX'] ) )
1654 ?
$options['USE INDEX']
1657 isset( $options['IGNORE INDEX'] ) &&
1658 is_array( $options['IGNORE INDEX'] )
1660 ?
$options['IGNORE INDEX']
1664 $this->selectOptionsIncludeLocking( $options ) &&
1665 $this->selectFieldsOrOptionsAggregate( $vars, $options )
1667 // Some DB types (postgres/oracle) disallow FOR UPDATE with aggregate
1668 // functions. Discourage use of such queries to encourage compatibility.
1670 $this->deprecationLogger
,
1671 __METHOD__
. ": aggregation used with a locking SELECT ($fname)."
1675 if ( is_array( $table ) ) {
1677 $this->tableNamesWithIndexClauseOrJOIN(
1678 $table, $useIndexes, $ignoreIndexes, $join_conds );
1679 } elseif ( $table != '' ) {
1681 $this->tableNamesWithIndexClauseOrJOIN(
1682 [ $table ], $useIndexes, $ignoreIndexes, [] );
1687 list( $startOpts, $useIndex, $preLimitTail, $postLimitTail, $ignoreIndex ) =
1688 $this->makeSelectOptions( $options );
1690 if ( is_array( $conds ) ) {
1691 $conds = $this->makeList( $conds, self
::LIST_AND
);
1694 if ( $conds === null ||
$conds === false ) {
1695 $this->queryLogger
->warning(
1699 . ' with incorrect parameters: $conds must be a string or an array'
1704 if ( $conds === '' ) {
1705 $sql = "SELECT $startOpts $fields $from $useIndex $ignoreIndex $preLimitTail";
1706 } elseif ( is_string( $conds ) ) {
1707 $sql = "SELECT $startOpts $fields $from $useIndex $ignoreIndex " .
1708 "WHERE $conds $preLimitTail";
1710 throw new DBUnexpectedError( $this, __METHOD__
. ' called with incorrect parameters' );
1713 if ( isset( $options['LIMIT'] ) ) {
1714 $sql = $this->limitResult( $sql, $options['LIMIT'],
1715 $options['OFFSET'] ??
false );
1717 $sql = "$sql $postLimitTail";
1719 if ( isset( $options['EXPLAIN'] ) ) {
1720 $sql = 'EXPLAIN ' . $sql;
1726 public function selectRow( $table, $vars, $conds, $fname = __METHOD__
,
1727 $options = [], $join_conds = []
1729 $options = (array)$options;
1730 $options['LIMIT'] = 1;
1731 $res = $this->select( $table, $vars, $conds, $fname, $options, $join_conds );
1733 if ( $res === false ) {
1737 if ( !$this->numRows( $res ) ) {
1741 $obj = $this->fetchObject( $res );
1746 public function estimateRowCount(
1747 $table, $var = '*', $conds = '', $fname = __METHOD__
, $options = [], $join_conds = []
1749 $conds = $this->normalizeConditions( $conds, $fname );
1750 $column = $this->extractSingleFieldFromList( $var );
1751 if ( is_string( $column ) && !in_array( $column, [ '*', '1' ] ) ) {
1752 $conds[] = "$column IS NOT NULL";
1755 $res = $this->select(
1756 $table, [ 'rowcount' => 'COUNT(*)' ], $conds, $fname, $options, $join_conds
1758 $row = $res ?
$this->fetchRow( $res ) : [];
1760 return isset( $row['rowcount'] ) ?
(int)$row['rowcount'] : 0;
1763 public function selectRowCount(
1764 $tables, $var = '*', $conds = '', $fname = __METHOD__
, $options = [], $join_conds = []
1766 $conds = $this->normalizeConditions( $conds, $fname );
1767 $column = $this->extractSingleFieldFromList( $var );
1768 if ( is_string( $column ) && !in_array( $column, [ '*', '1' ] ) ) {
1769 $conds[] = "$column IS NOT NULL";
1772 $res = $this->select(
1774 'tmp_count' => $this->buildSelectSubquery(
1783 [ 'rowcount' => 'COUNT(*)' ],
1787 $row = $res ?
$this->fetchRow( $res ) : [];
1789 return isset( $row['rowcount'] ) ?
(int)$row['rowcount'] : 0;
1793 * @param string|array $options
1796 private function selectOptionsIncludeLocking( $options ) {
1797 $options = (array)$options;
1798 foreach ( [ 'FOR UPDATE', 'LOCK IN SHARE MODE' ] as $lock ) {
1799 if ( in_array( $lock, $options, true ) ) {
1808 * @param array|string $fields
1809 * @param array|string $options
1812 private function selectFieldsOrOptionsAggregate( $fields, $options ) {
1813 foreach ( (array)$options as $key => $value ) {
1814 if ( is_string( $key ) ) {
1815 if ( preg_match( '/^(?:GROUP BY|HAVING)$/i', $key ) ) {
1818 } elseif ( is_string( $value ) ) {
1819 if ( preg_match( '/^(?:DISTINCT|DISTINCTROW)$/i', $value ) ) {
1825 $regex = '/^(?:COUNT|MIN|MAX|SUM|GROUP_CONCAT|LISTAGG|ARRAY_AGG)\s*\\(/i';
1826 foreach ( (array)$fields as $field ) {
1827 if ( is_string( $field ) && preg_match( $regex, $field ) ) {
1836 * @param array|string $conds
1837 * @param string $fname
1840 final protected function normalizeConditions( $conds, $fname ) {
1841 if ( $conds === null ||
$conds === false ) {
1842 $this->queryLogger
->warning(
1846 . ' with incorrect parameters: $conds must be a string or an array'
1851 if ( !is_array( $conds ) ) {
1852 $conds = ( $conds === '' ) ?
[] : [ $conds ];
1859 * @param array|string $var Field parameter in the style of select()
1860 * @return string|null Column name or null; ignores aliases
1861 * @throws DBUnexpectedError Errors out if multiple columns are given
1863 final protected function extractSingleFieldFromList( $var ) {
1864 if ( is_array( $var ) ) {
1867 } elseif ( count( $var ) == 1 ) {
1868 $column = $var[0] ??
reset( $var );
1870 throw new DBUnexpectedError( $this, __METHOD__
. ': got multiple columns.' );
1880 * Removes most variables from an SQL query and replaces them with X or N for numbers.
1881 * It's only slightly flawed. Don't use for anything important.
1883 * @param string $sql A SQL Query
1887 protected static function generalizeSQL( $sql ) {
1888 # This does the same as the regexp below would do, but in such a way
1889 # as to avoid crashing php on some large strings.
1890 # $sql = preg_replace( "/'([^\\\\']|\\\\.)*'|\"([^\\\\\"]|\\\\.)*\"/", "'X'", $sql );
1892 $sql = str_replace( "\\\\", '', $sql );
1893 $sql = str_replace( "\\'", '', $sql );
1894 $sql = str_replace( "\\\"", '', $sql );
1895 $sql = preg_replace( "/'.*'/s", "'X'", $sql );
1896 $sql = preg_replace( '/".*"/s', "'X'", $sql );
1898 # All newlines, tabs, etc replaced by single space
1899 $sql = preg_replace( '/\s+/', ' ', $sql );
1902 # except the ones surrounded by characters, e.g. l10n
1903 $sql = preg_replace( '/-?\d+(,-?\d+)+/s', 'N,...,N', $sql );
1904 $sql = preg_replace( '/(?<![a-zA-Z])-?\d+(?![a-zA-Z])/s', 'N', $sql );
1909 public function fieldExists( $table, $field, $fname = __METHOD__
) {
1910 $info = $this->fieldInfo( $table, $field );
1915 public function indexExists( $table, $index, $fname = __METHOD__
) {
1916 if ( !$this->tableExists( $table ) ) {
1920 $info = $this->indexInfo( $table, $index, $fname );
1921 if ( is_null( $info ) ) {
1924 return $info !== false;
1928 abstract public function tableExists( $table, $fname = __METHOD__
);
1930 public function indexUnique( $table, $index ) {
1931 $indexInfo = $this->indexInfo( $table, $index );
1933 if ( !$indexInfo ) {
1937 return !$indexInfo[0]->Non_unique
;
1941 * Helper for Database::insert().
1943 * @param array $options
1946 protected function makeInsertOptions( $options ) {
1947 return implode( ' ', $options );
1950 public function insert( $table, $a, $fname = __METHOD__
, $options = [] ) {
1951 # No rows to insert, easy just return now
1952 if ( !count( $a ) ) {
1956 $table = $this->tableName( $table );
1958 if ( !is_array( $options ) ) {
1959 $options = [ $options ];
1963 if ( isset( $options['fileHandle'] ) ) {
1964 $fh = $options['fileHandle'];
1966 $options = $this->makeInsertOptions( $options );
1968 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
1970 $keys = array_keys( $a[0] );
1973 $keys = array_keys( $a );
1976 $sql = 'INSERT ' . $options .
1977 " INTO $table (" . implode( ',', $keys ) . ') VALUES ';
1981 foreach ( $a as $row ) {
1987 $sql .= '(' . $this->makeList( $row ) . ')';
1990 $sql .= '(' . $this->makeList( $a ) . ')';
1993 if ( $fh !== null && false === fwrite( $fh, $sql ) ) {
1995 } elseif ( $fh !== null ) {
1999 return (bool)$this->query( $sql, $fname );
2003 * Make UPDATE options array for Database::makeUpdateOptions
2005 * @param array $options
2008 protected function makeUpdateOptionsArray( $options ) {
2009 if ( !is_array( $options ) ) {
2010 $options = [ $options ];
2015 if ( in_array( 'IGNORE', $options ) ) {
2023 * Make UPDATE options for the Database::update function
2025 * @param array $options The options passed to Database::update
2028 protected function makeUpdateOptions( $options ) {
2029 $opts = $this->makeUpdateOptionsArray( $options );
2031 return implode( ' ', $opts );
2034 public function update( $table, $values, $conds, $fname = __METHOD__
, $options = [] ) {
2035 $table = $this->tableName( $table );
2036 $opts = $this->makeUpdateOptions( $options );
2037 $sql = "UPDATE $opts $table SET " . $this->makeList( $values, self
::LIST_SET
);
2039 if ( $conds !== [] && $conds !== '*' ) {
2040 $sql .= " WHERE " . $this->makeList( $conds, self
::LIST_AND
);
2043 return (bool)$this->query( $sql, $fname );
2046 public function makeList( $a, $mode = self
::LIST_COMMA
) {
2047 if ( !is_array( $a ) ) {
2048 throw new DBUnexpectedError( $this, __METHOD__
. ' called with incorrect parameters' );
2054 foreach ( $a as $field => $value ) {
2056 if ( $mode == self
::LIST_AND
) {
2058 } elseif ( $mode == self
::LIST_OR
) {
2067 if ( ( $mode == self
::LIST_AND ||
$mode == self
::LIST_OR
) && is_numeric( $field ) ) {
2068 $list .= "($value)";
2069 } elseif ( $mode == self
::LIST_SET
&& is_numeric( $field ) ) {
2072 ( $mode == self
::LIST_AND ||
$mode == self
::LIST_OR
) && is_array( $value )
2074 // Remove null from array to be handled separately if found
2075 $includeNull = false;
2076 foreach ( array_keys( $value, null, true ) as $nullKey ) {
2077 $includeNull = true;
2078 unset( $value[$nullKey] );
2080 if ( count( $value ) == 0 && !$includeNull ) {
2081 throw new InvalidArgumentException(
2082 __METHOD__
. ": empty input for field $field" );
2083 } elseif ( count( $value ) == 0 ) {
2084 // only check if $field is null
2085 $list .= "$field IS NULL";
2087 // IN clause contains at least one valid element
2088 if ( $includeNull ) {
2089 // Group subconditions to ensure correct precedence
2092 if ( count( $value ) == 1 ) {
2093 // Special-case single values, as IN isn't terribly efficient
2094 // Don't necessarily assume the single key is 0; we don't
2095 // enforce linear numeric ordering on other arrays here.
2096 $value = array_values( $value )[0];
2097 $list .= $field . " = " . $this->addQuotes( $value );
2099 $list .= $field . " IN (" . $this->makeList( $value ) . ") ";
2101 // if null present in array, append IS NULL
2102 if ( $includeNull ) {
2103 $list .= " OR $field IS NULL)";
2106 } elseif ( $value === null ) {
2107 if ( $mode == self
::LIST_AND ||
$mode == self
::LIST_OR
) {
2108 $list .= "$field IS ";
2109 } elseif ( $mode == self
::LIST_SET
) {
2110 $list .= "$field = ";
2115 $mode == self
::LIST_AND ||
$mode == self
::LIST_OR ||
$mode == self
::LIST_SET
2117 $list .= "$field = ";
2119 $list .= $mode == self
::LIST_NAMES ?
$value : $this->addQuotes( $value );
2126 public function makeWhereFrom2d( $data, $baseKey, $subKey ) {
2129 foreach ( $data as $base => $sub ) {
2130 if ( count( $sub ) ) {
2131 $conds[] = $this->makeList(
2132 [ $baseKey => $base, $subKey => array_keys( $sub ) ],
2138 return $this->makeList( $conds, self
::LIST_OR
);
2140 // Nothing to search for...
2145 public function aggregateValue( $valuedata, $valuename = 'value' ) {
2149 public function bitNot( $field ) {
2153 public function bitAnd( $fieldLeft, $fieldRight ) {
2154 return "($fieldLeft & $fieldRight)";
2157 public function bitOr( $fieldLeft, $fieldRight ) {
2158 return "($fieldLeft | $fieldRight)";
2161 public function buildConcat( $stringList ) {
2162 return 'CONCAT(' . implode( ',', $stringList ) . ')';
2165 public function buildGroupConcatField(
2166 $delim, $table, $field, $conds = '', $join_conds = []
2168 $fld = "GROUP_CONCAT($field SEPARATOR " . $this->addQuotes( $delim ) . ')';
2170 return '(' . $this->selectSQLText( $table, $fld, $conds, null, [], $join_conds ) . ')';
2173 public function buildSubstring( $input, $startPosition, $length = null ) {
2174 $this->assertBuildSubstringParams( $startPosition, $length );
2175 $functionBody = "$input FROM $startPosition";
2176 if ( $length !== null ) {
2177 $functionBody .= " FOR $length";
2179 return 'SUBSTRING(' . $functionBody . ')';
2183 * Check type and bounds for parameters to self::buildSubstring()
2185 * All supported databases have substring functions that behave the same for
2186 * positive $startPosition and non-negative $length, but behaviors differ when
2187 * given 0 or negative $startPosition or negative $length. The simplest
2188 * solution to that is to just forbid those values.
2190 * @param int $startPosition
2191 * @param int|null $length
2194 protected function assertBuildSubstringParams( $startPosition, $length ) {
2195 if ( !is_int( $startPosition ) ||
$startPosition <= 0 ) {
2196 throw new InvalidArgumentException(
2197 '$startPosition must be a positive integer'
2200 if ( !( is_int( $length ) && $length >= 0 ||
$length === null ) ) {
2201 throw new InvalidArgumentException(
2202 '$length must be null or an integer greater than or equal to 0'
2207 public function buildStringCast( $field ) {
2211 public function buildIntegerCast( $field ) {
2212 return 'CAST( ' . $field . ' AS INTEGER )';
2215 public function buildSelectSubquery(
2216 $table, $vars, $conds = '', $fname = __METHOD__
,
2217 $options = [], $join_conds = []
2219 return new Subquery(
2220 $this->selectSQLText( $table, $vars, $conds, $fname, $options, $join_conds )
2224 public function databasesAreIndependent() {
2228 public function selectDB( $db ) {
2229 # Stub. Shouldn't cause serious problems if it's not overridden, but
2230 # if your database engine supports a concept similar to MySQL's
2231 # databases you may as well.
2232 $this->dbName
= $db;
2237 public function getDBname() {
2238 return $this->dbName
;
2241 public function getServer() {
2242 return $this->server
;
2245 public function tableName( $name, $format = 'quoted' ) {
2246 if ( $name instanceof Subquery
) {
2247 throw new DBUnexpectedError(
2249 __METHOD__
. ': got Subquery instance when expecting a string.'
2253 # Skip the entire process when we have a string quoted on both ends.
2254 # Note that we check the end so that we will still quote any use of
2255 # use of `database`.table. But won't break things if someone wants
2256 # to query a database table with a dot in the name.
2257 if ( $this->isQuotedIdentifier( $name ) ) {
2261 # Lets test for any bits of text that should never show up in a table
2262 # name. Basically anything like JOIN or ON which are actually part of
2263 # SQL queries, but may end up inside of the table value to combine
2264 # sql. Such as how the API is doing.
2265 # Note that we use a whitespace test rather than a \b test to avoid
2266 # any remote case where a word like on may be inside of a table name
2267 # surrounded by symbols which may be considered word breaks.
2268 if ( preg_match( '/(^|\s)(DISTINCT|JOIN|ON|AS)(\s|$)/i', $name ) !== 0 ) {
2269 $this->queryLogger
->warning(
2270 __METHOD__
. ": use of subqueries is not supported this way.",
2271 [ 'trace' => ( new RuntimeException() )->getTraceAsString() ]
2277 # Split database and table into proper variables.
2278 list( $database, $schema, $prefix, $table ) = $this->qualifiedTableComponents( $name );
2280 # Quote $table and apply the prefix if not quoted.
2281 # $tableName might be empty if this is called from Database::replaceVars()
2282 $tableName = "{$prefix}{$table}";
2283 if ( $format === 'quoted'
2284 && !$this->isQuotedIdentifier( $tableName )
2285 && $tableName !== ''
2287 $tableName = $this->addIdentifierQuotes( $tableName );
2290 # Quote $schema and $database and merge them with the table name if needed
2291 $tableName = $this->prependDatabaseOrSchema( $schema, $tableName, $format );
2292 $tableName = $this->prependDatabaseOrSchema( $database, $tableName, $format );
2298 * Get the table components needed for a query given the currently selected database
2300 * @param string $name Table name in the form of db.schema.table, db.table, or table
2301 * @return array (DB name or "" for default, schema name, table prefix, table name)
2303 protected function qualifiedTableComponents( $name ) {
2304 # We reverse the explode so that database.table and table both output the correct table.
2305 $dbDetails = explode( '.', $name, 3 );
2306 if ( count( $dbDetails ) == 3 ) {
2307 list( $database, $schema, $table ) = $dbDetails;
2308 # We don't want any prefix added in this case
2310 } elseif ( count( $dbDetails ) == 2 ) {
2311 list( $database, $table ) = $dbDetails;
2312 # We don't want any prefix added in this case
2314 # In dbs that support it, $database may actually be the schema
2315 # but that doesn't affect any of the functionality here
2318 list( $table ) = $dbDetails;
2319 if ( isset( $this->tableAliases
[$table] ) ) {
2320 $database = $this->tableAliases
[$table]['dbname'];
2321 $schema = is_string( $this->tableAliases
[$table]['schema'] )
2322 ?
$this->tableAliases
[$table]['schema']
2324 $prefix = is_string( $this->tableAliases
[$table]['prefix'] )
2325 ?
$this->tableAliases
[$table]['prefix']
2326 : $this->tablePrefix
;
2329 $schema = $this->schema
; # Default schema
2330 $prefix = $this->tablePrefix
; # Default prefix
2334 return [ $database, $schema, $prefix, $table ];
2338 * @param string|null $namespace Database or schema
2339 * @param string $relation Name of table, view, sequence, etc...
2340 * @param string $format One of (raw, quoted)
2341 * @return string Relation name with quoted and merged $namespace as needed
2343 private function prependDatabaseOrSchema( $namespace, $relation, $format ) {
2344 if ( strlen( $namespace ) ) {
2345 if ( $format === 'quoted' && !$this->isQuotedIdentifier( $namespace ) ) {
2346 $namespace = $this->addIdentifierQuotes( $namespace );
2348 $relation = $namespace . '.' . $relation;
2354 public function tableNames() {
2355 $inArray = func_get_args();
2358 foreach ( $inArray as $name ) {
2359 $retVal[$name] = $this->tableName( $name );
2365 public function tableNamesN() {
2366 $inArray = func_get_args();
2369 foreach ( $inArray as $name ) {
2370 $retVal[] = $this->tableName( $name );
2377 * Get an aliased table name
2379 * This returns strings like "tableName AS newTableName" for aliased tables
2380 * and "(SELECT * from tableA) newTablename" for subqueries (e.g. derived tables)
2382 * @see Database::tableName()
2383 * @param string|Subquery $table Table name or object with a 'sql' field
2384 * @param string|bool $alias Table alias (optional)
2385 * @return string SQL name for aliased table. Will not alias a table to its own name
2387 protected function tableNameWithAlias( $table, $alias = false ) {
2388 if ( is_string( $table ) ) {
2389 $quotedTable = $this->tableName( $table );
2390 } elseif ( $table instanceof Subquery
) {
2391 $quotedTable = (string)$table;
2393 throw new InvalidArgumentException( "Table must be a string or Subquery." );
2396 if ( !strlen( $alias ) ||
$alias === $table ) {
2397 if ( $table instanceof Subquery
) {
2398 throw new InvalidArgumentException( "Subquery table missing alias." );
2401 return $quotedTable;
2403 return $quotedTable . ' ' . $this->addIdentifierQuotes( $alias );
2408 * Gets an array of aliased table names
2410 * @param array $tables [ [alias] => table ]
2411 * @return string[] See tableNameWithAlias()
2413 protected function tableNamesWithAlias( $tables ) {
2415 foreach ( $tables as $alias => $table ) {
2416 if ( is_numeric( $alias ) ) {
2419 $retval[] = $this->tableNameWithAlias( $table, $alias );
2426 * Get an aliased field name
2427 * e.g. fieldName AS newFieldName
2429 * @param string $name Field name
2430 * @param string|bool $alias Alias (optional)
2431 * @return string SQL name for aliased field. Will not alias a field to its own name
2433 protected function fieldNameWithAlias( $name, $alias = false ) {
2434 if ( !$alias ||
(string)$alias === (string)$name ) {
2437 return $name . ' AS ' . $this->addIdentifierQuotes( $alias ); // PostgreSQL needs AS
2442 * Gets an array of aliased field names
2444 * @param array $fields [ [alias] => field ]
2445 * @return string[] See fieldNameWithAlias()
2447 protected function fieldNamesWithAlias( $fields ) {
2449 foreach ( $fields as $alias => $field ) {
2450 if ( is_numeric( $alias ) ) {
2453 $retval[] = $this->fieldNameWithAlias( $field, $alias );
2460 * Get the aliased table name clause for a FROM clause
2461 * which might have a JOIN and/or USE INDEX or IGNORE INDEX clause
2463 * @param array $tables ( [alias] => table )
2464 * @param array $use_index Same as for select()
2465 * @param array $ignore_index Same as for select()
2466 * @param array $join_conds Same as for select()
2469 protected function tableNamesWithIndexClauseOrJOIN(
2470 $tables, $use_index = [], $ignore_index = [], $join_conds = []
2474 $use_index = (array)$use_index;
2475 $ignore_index = (array)$ignore_index;
2476 $join_conds = (array)$join_conds;
2478 foreach ( $tables as $alias => $table ) {
2479 if ( !is_string( $alias ) ) {
2480 // No alias? Set it equal to the table name
2484 if ( is_array( $table ) ) {
2485 // A parenthesized group
2486 if ( count( $table ) > 1 ) {
2487 $joinedTable = '(' .
2488 $this->tableNamesWithIndexClauseOrJOIN(
2489 $table, $use_index, $ignore_index, $join_conds ) . ')';
2492 $innerTable = reset( $table );
2493 $innerAlias = key( $table );
2494 $joinedTable = $this->tableNameWithAlias(
2496 is_string( $innerAlias ) ?
$innerAlias : $innerTable
2500 $joinedTable = $this->tableNameWithAlias( $table, $alias );
2503 // Is there a JOIN clause for this table?
2504 if ( isset( $join_conds[$alias] ) ) {
2505 list( $joinType, $conds ) = $join_conds[$alias];
2506 $tableClause = $joinType;
2507 $tableClause .= ' ' . $joinedTable;
2508 if ( isset( $use_index[$alias] ) ) { // has USE INDEX?
2509 $use = $this->useIndexClause( implode( ',', (array)$use_index[$alias] ) );
2511 $tableClause .= ' ' . $use;
2514 if ( isset( $ignore_index[$alias] ) ) { // has IGNORE INDEX?
2515 $ignore = $this->ignoreIndexClause(
2516 implode( ',', (array)$ignore_index[$alias] ) );
2517 if ( $ignore != '' ) {
2518 $tableClause .= ' ' . $ignore;
2521 $on = $this->makeList( (array)$conds, self
::LIST_AND
);
2523 $tableClause .= ' ON (' . $on . ')';
2526 $retJOIN[] = $tableClause;
2527 } elseif ( isset( $use_index[$alias] ) ) {
2528 // Is there an INDEX clause for this table?
2529 $tableClause = $joinedTable;
2530 $tableClause .= ' ' . $this->useIndexClause(
2531 implode( ',', (array)$use_index[$alias] )
2534 $ret[] = $tableClause;
2535 } elseif ( isset( $ignore_index[$alias] ) ) {
2536 // Is there an INDEX clause for this table?
2537 $tableClause = $joinedTable;
2538 $tableClause .= ' ' . $this->ignoreIndexClause(
2539 implode( ',', (array)$ignore_index[$alias] )
2542 $ret[] = $tableClause;
2544 $tableClause = $joinedTable;
2546 $ret[] = $tableClause;
2550 // We can't separate explicit JOIN clauses with ',', use ' ' for those
2551 $implicitJoins = $ret ?
implode( ',', $ret ) : "";
2552 $explicitJoins = $retJOIN ?
implode( ' ', $retJOIN ) : "";
2554 // Compile our final table clause
2555 return implode( ' ', [ $implicitJoins, $explicitJoins ] );
2559 * Allows for index remapping in queries where this is not consistent across DBMS
2561 * @param string $index
2564 protected function indexName( $index ) {
2565 return $this->indexAliases
[$index] ??
$index;
2568 public function addQuotes( $s ) {
2569 if ( $s instanceof Blob
) {
2572 if ( $s === null ) {
2574 } elseif ( is_bool( $s ) ) {
2577 # This will also quote numeric values. This should be harmless,
2578 # and protects against weird problems that occur when they really
2579 # _are_ strings such as article titles and string->number->string
2580 # conversion is not 1:1.
2581 return "'" . $this->strencode( $s ) . "'";
2586 * Quotes an identifier using `backticks` or "double quotes" depending on the database type.
2587 * MySQL uses `backticks` while basically everything else uses double quotes.
2588 * Since MySQL is the odd one out here the double quotes are our generic
2589 * and we implement backticks in DatabaseMysqlBase.
2594 public function addIdentifierQuotes( $s ) {
2595 return '"' . str_replace( '"', '""', $s ) . '"';
2599 * Returns if the given identifier looks quoted or not according to
2600 * the database convention for quoting identifiers .
2602 * @note Do not use this to determine if untrusted input is safe.
2603 * A malicious user can trick this function.
2604 * @param string $name
2607 public function isQuotedIdentifier( $name ) {
2608 return $name[0] == '"' && substr( $name, -1, 1 ) == '"';
2613 * @param string $escapeChar
2616 protected function escapeLikeInternal( $s, $escapeChar = '`' ) {
2617 return str_replace( [ $escapeChar, '%', '_' ],
2618 [ "{$escapeChar}{$escapeChar}", "{$escapeChar}%", "{$escapeChar}_" ],
2622 public function buildLike() {
2623 $params = func_get_args();
2625 if ( count( $params ) > 0 && is_array( $params[0] ) ) {
2626 $params = $params[0];
2631 // We use ` instead of \ as the default LIKE escape character, since addQuotes()
2632 // may escape backslashes, creating problems of double escaping. The `
2633 // character has good cross-DBMS compatibility, avoiding special operators
2634 // in MS SQL like ^ and %
2637 foreach ( $params as $value ) {
2638 if ( $value instanceof LikeMatch
) {
2639 $s .= $value->toString();
2641 $s .= $this->escapeLikeInternal( $value, $escapeChar );
2646 $this->addQuotes( $s ) . ' ESCAPE ' . $this->addQuotes( $escapeChar ) . ' ';
2649 public function anyChar() {
2650 return new LikeMatch( '_' );
2653 public function anyString() {
2654 return new LikeMatch( '%' );
2657 public function nextSequenceValue( $seqName ) {
2662 * USE INDEX clause. Unlikely to be useful for anything but MySQL. This
2663 * is only needed because a) MySQL must be as efficient as possible due to
2664 * its use on Wikipedia, and b) MySQL 4.0 is kind of dumb sometimes about
2665 * which index to pick. Anyway, other databases might have different
2666 * indexes on a given table. So don't bother overriding this unless you're
2668 * @param string $index
2671 public function useIndexClause( $index ) {
2676 * IGNORE INDEX clause. Unlikely to be useful for anything but MySQL. This
2677 * is only needed because a) MySQL must be as efficient as possible due to
2678 * its use on Wikipedia, and b) MySQL 4.0 is kind of dumb sometimes about
2679 * which index to pick. Anyway, other databases might have different
2680 * indexes on a given table. So don't bother overriding this unless you're
2682 * @param string $index
2685 public function ignoreIndexClause( $index ) {
2689 public function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__
) {
2690 if ( count( $rows ) == 0 ) {
2695 if ( !is_array( reset( $rows ) ) ) {
2700 $this->startAtomic( $fname, self
::ATOMIC_CANCELABLE
);
2701 $affectedRowCount = 0;
2702 foreach ( $rows as $row ) {
2703 // Delete rows which collide with this one
2704 $indexWhereClauses = [];
2705 foreach ( $uniqueIndexes as $index ) {
2706 $indexColumns = (array)$index;
2707 $indexRowValues = array_intersect_key( $row, array_flip( $indexColumns ) );
2708 if ( count( $indexRowValues ) != count( $indexColumns ) ) {
2709 throw new DBUnexpectedError(
2711 'New record does not provide all values for unique key (' .
2712 implode( ', ', $indexColumns ) . ')'
2714 } elseif ( in_array( null, $indexRowValues, true ) ) {
2715 throw new DBUnexpectedError(
2717 'New record has a null value for unique key (' .
2718 implode( ', ', $indexColumns ) . ')'
2721 $indexWhereClauses[] = $this->makeList( $indexRowValues, LIST_AND
);
2724 if ( $indexWhereClauses ) {
2725 $this->delete( $table, $this->makeList( $indexWhereClauses, LIST_OR
), $fname );
2726 $affectedRowCount +
= $this->affectedRows();
2729 // Now insert the row
2730 $this->insert( $table, $row, $fname );
2731 $affectedRowCount +
= $this->affectedRows();
2733 $this->endAtomic( $fname );
2734 $this->affectedRowCount
= $affectedRowCount;
2735 } catch ( Exception
$e ) {
2736 $this->cancelAtomic( $fname );
2742 * REPLACE query wrapper for MySQL and SQLite, which have a native REPLACE
2745 * @param string $table Table name
2746 * @param array|string $rows Row(s) to insert
2747 * @param string $fname Caller function name
2749 * @return ResultWrapper
2751 protected function nativeReplace( $table, $rows, $fname ) {
2752 $table = $this->tableName( $table );
2755 if ( !is_array( reset( $rows ) ) ) {
2759 $sql = "REPLACE INTO $table (" . implode( ',', array_keys( $rows[0] ) ) . ') VALUES ';
2762 foreach ( $rows as $row ) {
2769 $sql .= '(' . $this->makeList( $row ) . ')';
2772 return $this->query( $sql, $fname );
2775 public function upsert( $table, array $rows, array $uniqueIndexes, array $set,
2778 if ( !count( $rows ) ) {
2779 return true; // nothing to do
2782 if ( !is_array( reset( $rows ) ) ) {
2786 if ( count( $uniqueIndexes ) ) {
2787 $clauses = []; // list WHERE clauses that each identify a single row
2788 foreach ( $rows as $row ) {
2789 foreach ( $uniqueIndexes as $index ) {
2790 $index = is_array( $index ) ?
$index : [ $index ]; // columns
2791 $rowKey = []; // unique key to this row
2792 foreach ( $index as $column ) {
2793 $rowKey[$column] = $row[$column];
2795 $clauses[] = $this->makeList( $rowKey, self
::LIST_AND
);
2798 $where = [ $this->makeList( $clauses, self
::LIST_OR
) ];
2803 $affectedRowCount = 0;
2805 $this->startAtomic( $fname, self
::ATOMIC_CANCELABLE
);
2806 # Update any existing conflicting row(s)
2807 if ( $where !== false ) {
2808 $ok = $this->update( $table, $set, $where, $fname );
2809 $affectedRowCount +
= $this->affectedRows();
2813 # Now insert any non-conflicting row(s)
2814 $ok = $this->insert( $table, $rows, $fname, [ 'IGNORE' ] ) && $ok;
2815 $affectedRowCount +
= $this->affectedRows();
2816 $this->endAtomic( $fname );
2817 $this->affectedRowCount
= $affectedRowCount;
2818 } catch ( Exception
$e ) {
2819 $this->cancelAtomic( $fname );
2826 public function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds,
2830 throw new DBUnexpectedError( $this, __METHOD__
. ' called with empty $conds' );
2833 $delTable = $this->tableName( $delTable );
2834 $joinTable = $this->tableName( $joinTable );
2835 $sql = "DELETE FROM $delTable WHERE $delVar IN (SELECT $joinVar FROM $joinTable ";
2836 if ( $conds != '*' ) {
2837 $sql .= 'WHERE ' . $this->makeList( $conds, self
::LIST_AND
);
2841 $this->query( $sql, $fname );
2844 public function textFieldSize( $table, $field ) {
2845 $table = $this->tableName( $table );
2846 $sql = "SHOW COLUMNS FROM $table LIKE \"$field\";";
2847 $res = $this->query( $sql, __METHOD__
);
2848 $row = $this->fetchObject( $res );
2852 if ( preg_match( '/\((.*)\)/', $row->Type
, $m ) ) {
2861 public function delete( $table, $conds, $fname = __METHOD__
) {
2863 throw new DBUnexpectedError( $this, __METHOD__
. ' called with no conditions' );
2866 $table = $this->tableName( $table );
2867 $sql = "DELETE FROM $table";
2869 if ( $conds != '*' ) {
2870 if ( is_array( $conds ) ) {
2871 $conds = $this->makeList( $conds, self
::LIST_AND
);
2873 $sql .= ' WHERE ' . $conds;
2876 return $this->query( $sql, $fname );
2879 final public function insertSelect(
2880 $destTable, $srcTable, $varMap, $conds,
2881 $fname = __METHOD__
, $insertOptions = [], $selectOptions = [], $selectJoinConds = []
2883 static $hints = [ 'NO_AUTO_COLUMNS' ];
2885 $insertOptions = (array)$insertOptions;
2886 $selectOptions = (array)$selectOptions;
2888 if ( $this->cliMode
&& $this->isInsertSelectSafe( $insertOptions, $selectOptions ) ) {
2889 // For massive migrations with downtime, we don't want to select everything
2890 // into memory and OOM, so do all this native on the server side if possible.
2891 return $this->nativeInsertSelect(
2897 array_diff( $insertOptions, $hints ),
2903 return $this->nonNativeInsertSelect(
2909 array_diff( $insertOptions, $hints ),
2916 * @param array $insertOptions INSERT options
2917 * @param array $selectOptions SELECT options
2918 * @return bool Whether an INSERT SELECT with these options will be replication safe
2921 protected function isInsertSelectSafe( array $insertOptions, array $selectOptions ) {
2926 * Implementation of insertSelect() based on select() and insert()
2928 * @see IDatabase::insertSelect()
2930 * @param string $destTable
2931 * @param string|array $srcTable
2932 * @param array $varMap
2933 * @param array $conds
2934 * @param string $fname
2935 * @param array $insertOptions
2936 * @param array $selectOptions
2937 * @param array $selectJoinConds
2940 protected function nonNativeInsertSelect( $destTable, $srcTable, $varMap, $conds,
2941 $fname = __METHOD__
,
2942 $insertOptions = [], $selectOptions = [], $selectJoinConds = []
2944 // For web requests, do a locking SELECT and then INSERT. This puts the SELECT burden
2945 // on only the master (without needing row-based-replication). It also makes it easy to
2946 // know how big the INSERT is going to be.
2948 foreach ( $varMap as $dstColumn => $sourceColumnOrSql ) {
2949 $fields[] = $this->fieldNameWithAlias( $sourceColumnOrSql, $dstColumn );
2951 $selectOptions[] = 'FOR UPDATE';
2952 $res = $this->select(
2953 $srcTable, implode( ',', $fields ), $conds, $fname, $selectOptions, $selectJoinConds
2960 $affectedRowCount = 0;
2961 $this->startAtomic( $fname, self
::ATOMIC_CANCELABLE
);
2964 foreach ( $res as $row ) {
2965 $rows[] = (array)$row;
2967 // Avoid inserts that are too huge
2968 if ( count( $rows ) >= $this->nonNativeInsertSelectBatchSize
) {
2969 $ok = $this->insert( $destTable, $rows, $fname, $insertOptions );
2973 $affectedRowCount +
= $this->affectedRows();
2977 if ( $rows && $ok ) {
2978 $ok = $this->insert( $destTable, $rows, $fname, $insertOptions );
2980 $affectedRowCount +
= $this->affectedRows();
2984 $this->endAtomic( $fname );
2985 $this->affectedRowCount
= $affectedRowCount;
2987 $this->cancelAtomic( $fname );
2990 } catch ( Exception
$e ) {
2991 $this->cancelAtomic( $fname );
2997 * Native server-side implementation of insertSelect() for situations where
2998 * we don't want to select everything into memory
3000 * @see IDatabase::insertSelect()
3001 * @param string $destTable
3002 * @param string|array $srcTable
3003 * @param array $varMap
3004 * @param array $conds
3005 * @param string $fname
3006 * @param array $insertOptions
3007 * @param array $selectOptions
3008 * @param array $selectJoinConds
3011 protected function nativeInsertSelect( $destTable, $srcTable, $varMap, $conds,
3012 $fname = __METHOD__
,
3013 $insertOptions = [], $selectOptions = [], $selectJoinConds = []
3015 $destTable = $this->tableName( $destTable );
3017 if ( !is_array( $insertOptions ) ) {
3018 $insertOptions = [ $insertOptions ];
3021 $insertOptions = $this->makeInsertOptions( $insertOptions );
3023 $selectSql = $this->selectSQLText(
3025 array_values( $varMap ),
3032 $sql = "INSERT $insertOptions" .
3033 " INTO $destTable (" . implode( ',', array_keys( $varMap ) ) . ') ' .
3036 return $this->query( $sql, $fname );
3040 * Construct a LIMIT query with optional offset. This is used for query
3041 * pages. The SQL should be adjusted so that only the first $limit rows
3042 * are returned. If $offset is provided as well, then the first $offset
3043 * rows should be discarded, and the next $limit rows should be returned.
3044 * If the result of the query is not ordered, then the rows to be returned
3045 * are theoretically arbitrary.
3047 * $sql is expected to be a SELECT, if that makes a difference.
3049 * The version provided by default works in MySQL and SQLite. It will very
3050 * likely need to be overridden for most other DBMSes.
3052 * @param string $sql SQL query we will append the limit too
3053 * @param int $limit The SQL limit
3054 * @param int|bool $offset The SQL offset (default false)
3055 * @throws DBUnexpectedError
3058 public function limitResult( $sql, $limit, $offset = false ) {
3059 if ( !is_numeric( $limit ) ) {
3060 throw new DBUnexpectedError( $this,
3061 "Invalid non-numeric limit passed to limitResult()\n" );
3064 return "$sql LIMIT "
3065 . ( ( is_numeric( $offset ) && $offset != 0 ) ?
"{$offset}," : "" )
3069 public function unionSupportsOrderAndLimit() {
3070 return true; // True for almost every DB supported
3073 public function unionQueries( $sqls, $all ) {
3074 $glue = $all ?
') UNION ALL (' : ') UNION (';
3076 return '(' . implode( $glue, $sqls ) . ')';
3079 public function unionConditionPermutations(
3080 $table, $vars, array $permute_conds, $extra_conds = '', $fname = __METHOD__
,
3081 $options = [], $join_conds = []
3083 // First, build the Cartesian product of $permute_conds
3085 foreach ( $permute_conds as $field => $values ) {
3087 // Skip empty $values
3090 $values = array_unique( $values ); // For sanity
3092 foreach ( $conds as $cond ) {
3093 foreach ( $values as $value ) {
3094 $cond[$field] = $value;
3095 $newConds[] = $cond; // Arrays are by-value, not by-reference, so this works
3101 $extra_conds = $extra_conds === '' ?
[] : (array)$extra_conds;
3103 // If there's just one condition and no subordering, hand off to
3104 // selectSQLText directly.
3105 if ( count( $conds ) === 1 &&
3106 ( !isset( $options['INNER ORDER BY'] ) ||
!$this->unionSupportsOrderAndLimit() )
3108 return $this->selectSQLText(
3109 $table, $vars, $conds[0] +
$extra_conds, $fname, $options, $join_conds
3113 // Otherwise, we need to pull out the order and limit to apply after
3114 // the union. Then build the SQL queries for each set of conditions in
3115 // $conds. Then union them together (using UNION ALL, because the
3116 // product *should* already be distinct).
3117 $orderBy = $this->makeOrderBy( $options );
3118 $limit = $options['LIMIT'] ??
null;
3119 $offset = $options['OFFSET'] ??
false;
3120 $all = empty( $options['NOTALL'] ) && !in_array( 'NOTALL', $options );
3121 if ( !$this->unionSupportsOrderAndLimit() ) {
3122 unset( $options['ORDER BY'], $options['LIMIT'], $options['OFFSET'] );
3124 if ( array_key_exists( 'INNER ORDER BY', $options ) ) {
3125 $options['ORDER BY'] = $options['INNER ORDER BY'];
3127 if ( $limit !== null && is_numeric( $offset ) && $offset != 0 ) {
3128 // We need to increase the limit by the offset rather than
3129 // using the offset directly, otherwise it'll skip incorrectly
3130 // in the subqueries.
3131 $options['LIMIT'] = $limit +
$offset;
3132 unset( $options['OFFSET'] );
3137 foreach ( $conds as $cond ) {
3138 $sqls[] = $this->selectSQLText(
3139 $table, $vars, $cond +
$extra_conds, $fname, $options, $join_conds
3142 $sql = $this->unionQueries( $sqls, $all ) . $orderBy;
3143 if ( $limit !== null ) {
3144 $sql = $this->limitResult( $sql, $limit, $offset );
3150 public function conditional( $cond, $trueVal, $falseVal ) {
3151 if ( is_array( $cond ) ) {
3152 $cond = $this->makeList( $cond, self
::LIST_AND
);
3155 return " (CASE WHEN $cond THEN $trueVal ELSE $falseVal END) ";
3158 public function strreplace( $orig, $old, $new ) {
3159 return "REPLACE({$orig}, {$old}, {$new})";
3162 public function getServerUptime() {
3166 public function wasDeadlock() {
3170 public function wasLockTimeout() {
3174 public function wasConnectionLoss() {
3175 return $this->wasConnectionError( $this->lastErrno() );
3178 public function wasReadOnlyError() {
3182 public function wasErrorReissuable() {
3184 $this->wasDeadlock() ||
3185 $this->wasLockTimeout() ||
3186 $this->wasConnectionLoss()
3191 * Do not use this method outside of Database/DBError classes
3193 * @param int|string $errno
3194 * @return bool Whether the given query error was a connection drop
3196 public function wasConnectionError( $errno ) {
3201 * @return bool Whether it is safe to assume the given error only caused statement rollback
3202 * @note This is for backwards compatibility for callers catching DBError exceptions in
3203 * order to ignore problems like duplicate key errors or foriegn key violations
3206 protected function wasKnownStatementRollbackError() {
3207 return false; // don't know; it could have caused a transaction rollback
3210 public function deadlockLoop() {
3211 $args = func_get_args();
3212 $function = array_shift( $args );
3213 $tries = self
::DEADLOCK_TRIES
;
3215 $this->begin( __METHOD__
);
3218 /** @var Exception $e */
3222 $retVal = $function( ...$args );
3224 } catch ( DBQueryError
$e ) {
3225 if ( $this->wasDeadlock() ) {
3226 // Retry after a randomized delay
3227 usleep( mt_rand( self
::DEADLOCK_DELAY_MIN
, self
::DEADLOCK_DELAY_MAX
) );
3229 // Throw the error back up
3233 } while ( --$tries > 0 );
3235 if ( $tries <= 0 ) {
3236 // Too many deadlocks; give up
3237 $this->rollback( __METHOD__
);
3240 $this->commit( __METHOD__
);
3246 public function masterPosWait( DBMasterPos
$pos, $timeout ) {
3247 # Real waits are implemented in the subclass.
3251 public function getReplicaPos() {
3256 public function getMasterPos() {
3261 public function serverIsReadOnly() {
3265 final public function onTransactionResolution( callable
$callback, $fname = __METHOD__
) {
3266 if ( !$this->trxLevel
) {
3267 throw new DBUnexpectedError( $this, "No transaction is active." );
3269 $this->trxEndCallbacks
[] = [ $callback, $fname, $this->currentAtomicSectionId() ];
3272 final public function onTransactionCommitOrIdle( callable
$callback, $fname = __METHOD__
) {
3273 if ( !$this->trxLevel
&& $this->getTransactionRoundId() ) {
3274 // Start an implicit transaction similar to how query() does
3275 $this->begin( __METHOD__
, self
::TRANSACTION_INTERNAL
);
3276 $this->trxAutomatic
= true;
3279 $this->trxIdleCallbacks
[] = [ $callback, $fname, $this->currentAtomicSectionId() ];
3280 if ( !$this->trxLevel
) {
3281 $this->runOnTransactionIdleCallbacks( self
::TRIGGER_IDLE
);
3285 final public function onTransactionIdle( callable
$callback, $fname = __METHOD__
) {
3286 $this->onTransactionCommitOrIdle( $callback, $fname );
3289 final public function onTransactionPreCommitOrIdle( callable
$callback, $fname = __METHOD__
) {
3290 if ( !$this->trxLevel
&& $this->getTransactionRoundId() ) {
3291 // Start an implicit transaction similar to how query() does
3292 $this->begin( __METHOD__
, self
::TRANSACTION_INTERNAL
);
3293 $this->trxAutomatic
= true;
3296 if ( $this->trxLevel
) {
3297 $this->trxPreCommitCallbacks
[] = [ $callback, $fname, $this->currentAtomicSectionId() ];
3299 // No transaction is active nor will start implicitly, so make one for this callback
3300 $this->startAtomic( __METHOD__
, self
::ATOMIC_CANCELABLE
);
3303 $this->endAtomic( __METHOD__
);
3304 } catch ( Exception
$e ) {
3305 $this->cancelAtomic( __METHOD__
);
3312 * @return AtomicSectionIdentifier|null ID of the topmost atomic section level
3314 private function currentAtomicSectionId() {
3315 if ( $this->trxLevel
&& $this->trxAtomicLevels
) {
3316 $levelInfo = end( $this->trxAtomicLevels
);
3318 return $levelInfo[1];
3325 * @param AtomicSectionIdentifier $old
3326 * @param AtomicSectionIdentifier $new
3328 private function reassignCallbacksForSection(
3329 AtomicSectionIdentifier
$old, AtomicSectionIdentifier
$new
3331 foreach ( $this->trxPreCommitCallbacks
as $key => $info ) {
3332 if ( $info[2] === $old ) {
3333 $this->trxPreCommitCallbacks
[$key][2] = $new;
3336 foreach ( $this->trxIdleCallbacks
as $key => $info ) {
3337 if ( $info[2] === $old ) {
3338 $this->trxIdleCallbacks
[$key][2] = $new;
3341 foreach ( $this->trxEndCallbacks
as $key => $info ) {
3342 if ( $info[2] === $old ) {
3343 $this->trxEndCallbacks
[$key][2] = $new;
3349 * @param AtomicSectionIdentifier[] $sectionIds ID of an actual savepoint
3350 * @throws UnexpectedValueException
3352 private function modifyCallbacksForCancel( array $sectionIds ) {
3353 // Cancel the "on commit" callbacks owned by this savepoint
3354 $this->trxIdleCallbacks
= array_filter(
3355 $this->trxIdleCallbacks
,
3356 function ( $entry ) use ( $sectionIds ) {
3357 return !in_array( $entry[2], $sectionIds, true );
3360 $this->trxPreCommitCallbacks
= array_filter(
3361 $this->trxPreCommitCallbacks
,
3362 function ( $entry ) use ( $sectionIds ) {
3363 return !in_array( $entry[2], $sectionIds, true );
3366 // Make "on resolution" callbacks owned by this savepoint to perceive a rollback
3367 foreach ( $this->trxEndCallbacks
as $key => $entry ) {
3368 if ( in_array( $entry[2], $sectionIds, true ) ) {
3369 $callback = $entry[0];
3370 $this->trxEndCallbacks
[$key][0] = function () use ( $callback ) {
3371 return $callback( self
::TRIGGER_ROLLBACK
, $this );
3377 final public function setTransactionListener( $name, callable
$callback = null ) {
3379 $this->trxRecurringCallbacks
[$name] = $callback;
3381 unset( $this->trxRecurringCallbacks
[$name] );
3386 * Whether to disable running of post-COMMIT/ROLLBACK callbacks
3388 * This method should not be used outside of Database/LoadBalancer
3390 * @param bool $suppress
3393 final public function setTrxEndCallbackSuppression( $suppress ) {
3394 $this->trxEndCallbacksSuppressed
= $suppress;
3398 * Actually consume and run any "on transaction idle/resolution" callbacks.
3400 * This method should not be used outside of Database/LoadBalancer
3402 * @param int $trigger IDatabase::TRIGGER_* constant
3403 * @return int Number of callbacks attempted
3407 public function runOnTransactionIdleCallbacks( $trigger ) {
3408 if ( $this->trxLevel
) { // sanity
3409 throw new DBUnexpectedError( $this, __METHOD__
. ': a transaction is still open.' );
3412 if ( $this->trxEndCallbacksSuppressed
) {
3417 $autoTrx = $this->getFlag( self
::DBO_TRX
); // automatic begin() enabled?
3418 /** @var Exception $e */
3419 $e = null; // first exception
3420 do { // callbacks may add callbacks :)
3421 $callbacks = array_merge(
3422 $this->trxIdleCallbacks
,
3423 $this->trxEndCallbacks
// include "transaction resolution" callbacks
3425 $this->trxIdleCallbacks
= []; // consumed (and recursion guard)
3426 $this->trxEndCallbacks
= []; // consumed (recursion guard)
3427 foreach ( $callbacks as $callback ) {
3429 list( $phpCallback ) = $callback;
3430 $this->clearFlag( self
::DBO_TRX
); // make each query its own transaction
3432 call_user_func( $phpCallback, $trigger, $this );
3433 } catch ( Exception
$ex ) {
3434 call_user_func( $this->errorLogger
, $ex );
3436 // Some callbacks may use startAtomic/endAtomic, so make sure
3437 // their transactions are ended so other callbacks don't fail
3438 if ( $this->trxLevel() ) {
3439 $this->rollback( __METHOD__
, self
::FLUSHING_INTERNAL
);
3443 $this->setFlag( self
::DBO_TRX
); // restore automatic begin()
3445 $this->clearFlag( self
::DBO_TRX
); // restore auto-commit
3449 } while ( count( $this->trxIdleCallbacks
) );
3451 if ( $e instanceof Exception
) {
3452 throw $e; // re-throw any first exception
3459 * Actually consume and run any "on transaction pre-commit" callbacks.
3461 * This method should not be used outside of Database/LoadBalancer
3464 * @return int Number of callbacks attempted
3467 public function runOnTransactionPreCommitCallbacks() {
3470 $e = null; // first exception
3471 do { // callbacks may add callbacks :)
3472 $callbacks = $this->trxPreCommitCallbacks
;
3473 $this->trxPreCommitCallbacks
= []; // consumed (and recursion guard)
3474 foreach ( $callbacks as $callback ) {
3477 list( $phpCallback ) = $callback;
3478 $phpCallback( $this );
3479 } catch ( Exception
$ex ) {
3480 $this->errorLogger( $ex );
3484 } while ( count( $this->trxPreCommitCallbacks
) );
3486 if ( $e instanceof Exception
) {
3487 throw $e; // re-throw any first exception
3494 * Actually run any "transaction listener" callbacks.
3496 * This method should not be used outside of Database/LoadBalancer
3498 * @param int $trigger IDatabase::TRIGGER_* constant
3502 public function runTransactionListenerCallbacks( $trigger ) {
3503 if ( $this->trxEndCallbacksSuppressed
) {
3507 /** @var Exception $e */
3508 $e = null; // first exception
3510 foreach ( $this->trxRecurringCallbacks
as $phpCallback ) {
3512 $phpCallback( $trigger, $this );
3513 } catch ( Exception
$ex ) {
3514 ( $this->errorLogger
)( $ex );
3519 if ( $e instanceof Exception
) {
3520 throw $e; // re-throw any first exception
3525 * Create a savepoint
3527 * This is used internally to implement atomic sections. It should not be
3531 * @param string $identifier Identifier for the savepoint
3532 * @param string $fname Calling function name
3534 protected function doSavepoint( $identifier, $fname ) {
3535 $this->query( 'SAVEPOINT ' . $this->addIdentifierQuotes( $identifier ), $fname );
3539 * Release a savepoint
3541 * This is used internally to implement atomic sections. It should not be
3545 * @param string $identifier Identifier for the savepoint
3546 * @param string $fname Calling function name
3548 protected function doReleaseSavepoint( $identifier, $fname ) {
3549 $this->query( 'RELEASE SAVEPOINT ' . $this->addIdentifierQuotes( $identifier ), $fname );
3553 * Rollback to a savepoint
3555 * This is used internally to implement atomic sections. It should not be
3559 * @param string $identifier Identifier for the savepoint
3560 * @param string $fname Calling function name
3562 protected function doRollbackToSavepoint( $identifier, $fname ) {
3563 $this->query( 'ROLLBACK TO SAVEPOINT ' . $this->addIdentifierQuotes( $identifier ), $fname );
3567 * @param string $fname
3570 private function nextSavepointId( $fname ) {
3571 $savepointId = self
::$SAVEPOINT_PREFIX . ++
$this->trxAtomicCounter
;
3572 if ( strlen( $savepointId ) > 30 ) {
3573 // 30 == Oracle's identifier length limit (pre 12c)
3574 // With a 22 character prefix, that puts the highest number at 99999999.
3575 throw new DBUnexpectedError(
3577 'There have been an excessively large number of atomic sections in a transaction'
3578 . " started by $this->trxFname (at $fname)"
3582 return $savepointId;
3585 final public function startAtomic(
3586 $fname = __METHOD__
, $cancelable = self
::ATOMIC_NOT_CANCELABLE
3588 $savepointId = $cancelable === self
::ATOMIC_CANCELABLE ? self
::$NOT_APPLICABLE : null;
3590 if ( !$this->trxLevel
) {
3591 $this->begin( $fname, self
::TRANSACTION_INTERNAL
); // sets trxAutomatic
3592 // If DBO_TRX is set, a series of startAtomic/endAtomic pairs will result
3593 // in all changes being in one transaction to keep requests transactional.
3594 if ( $this->getFlag( self
::DBO_TRX
) ) {
3595 // Since writes could happen in between the topmost atomic sections as part
3596 // of the transaction, those sections will need savepoints.
3597 $savepointId = $this->nextSavepointId( $fname );
3598 $this->doSavepoint( $savepointId, $fname );
3600 $this->trxAutomaticAtomic
= true;
3602 } elseif ( $cancelable === self
::ATOMIC_CANCELABLE
) {
3603 $savepointId = $this->nextSavepointId( $fname );
3604 $this->doSavepoint( $savepointId, $fname );
3607 $sectionId = new AtomicSectionIdentifier
;
3608 $this->trxAtomicLevels
[] = [ $fname, $sectionId, $savepointId ];
3613 final public function endAtomic( $fname = __METHOD__
) {
3614 if ( !$this->trxLevel ||
!$this->trxAtomicLevels
) {
3615 throw new DBUnexpectedError( $this, "No atomic section is open (got $fname)." );
3618 // Check if the current section matches $fname
3619 $pos = count( $this->trxAtomicLevels
) - 1;
3620 list( $savedFname, $sectionId, $savepointId ) = $this->trxAtomicLevels
[$pos];
3622 if ( $savedFname !== $fname ) {
3623 throw new DBUnexpectedError(
3625 "Invalid atomic section ended (got $fname but expected $savedFname)."
3629 // Remove the last section (no need to re-index the array)
3630 array_pop( $this->trxAtomicLevels
);
3632 if ( !$this->trxAtomicLevels
&& $this->trxAutomaticAtomic
) {
3633 $this->commit( $fname, self
::FLUSHING_INTERNAL
);
3634 } elseif ( $savepointId !== null && $savepointId !== self
::$NOT_APPLICABLE ) {
3635 $this->doReleaseSavepoint( $savepointId, $fname );
3638 // Hoist callback ownership for callbacks in the section that just ended;
3639 // all callbacks should have an owner that is present in trxAtomicLevels.
3640 $currentSectionId = $this->currentAtomicSectionId();
3641 if ( $currentSectionId ) {
3642 $this->reassignCallbacksForSection( $sectionId, $currentSectionId );
3646 final public function cancelAtomic(
3647 $fname = __METHOD__
, AtomicSectionIdentifier
$sectionId = null
3649 if ( !$this->trxLevel ||
!$this->trxAtomicLevels
) {
3650 throw new DBUnexpectedError( $this, "No atomic section is open (got $fname)." );
3653 if ( $sectionId !== null ) {
3654 // Find the (last) section with the given $sectionId
3656 foreach ( $this->trxAtomicLevels
as $i => list( $asFname, $asId, $spId ) ) {
3657 if ( $asId === $sectionId ) {
3662 throw new DBUnexpectedError( "Atomic section not found (for $fname)" );
3664 // Remove all descendant sections and re-index the array
3666 $len = count( $this->trxAtomicLevels
);
3667 for ( $i = $pos +
1; $i < $len; ++
$i ) {
3668 $excisedIds[] = $this->trxAtomicLevels
[$i][1];
3670 $this->trxAtomicLevels
= array_slice( $this->trxAtomicLevels
, 0, $pos +
1 );
3671 $this->modifyCallbacksForCancel( $excisedIds );
3674 // Check if the current section matches $fname
3675 $pos = count( $this->trxAtomicLevels
) - 1;
3676 list( $savedFname, $savedSectionId, $savepointId ) = $this->trxAtomicLevels
[$pos];
3678 if ( $savedFname !== $fname ) {
3679 throw new DBUnexpectedError(
3681 "Invalid atomic section ended (got $fname but expected $savedFname)."
3685 // Remove the last section (no need to re-index the array)
3686 array_pop( $this->trxAtomicLevels
);
3687 $this->modifyCallbacksForCancel( [ $savedSectionId ] );
3689 if ( $savepointId !== null ) {
3690 // Rollback the transaction to the state just before this atomic section
3691 if ( $savepointId === self
::$NOT_APPLICABLE ) {
3692 $this->rollback( $fname, self
::FLUSHING_INTERNAL
);
3694 $this->doRollbackToSavepoint( $savepointId, $fname );
3695 $this->trxStatus
= self
::STATUS_TRX_OK
; // no exception; recovered
3696 $this->trxStatusIgnoredCause
= null;
3698 } elseif ( $this->trxStatus
> self
::STATUS_TRX_ERROR
) {
3699 // Put the transaction into an error state if it's not already in one
3700 $this->trxStatus
= self
::STATUS_TRX_ERROR
;
3701 $this->trxStatusCause
= new DBUnexpectedError(
3703 "Uncancelable atomic section canceled (got $fname)."
3707 $this->affectedRowCount
= 0; // for the sake of consistency
3710 final public function doAtomicSection(
3711 $fname, callable
$callback, $cancelable = self
::ATOMIC_NOT_CANCELABLE
3713 $sectionId = $this->startAtomic( $fname, $cancelable );
3715 $res = $callback( $this, $fname );
3716 } catch ( Exception
$e ) {
3717 $this->cancelAtomic( $fname, $sectionId );
3721 $this->endAtomic( $fname );
3726 final public function begin( $fname = __METHOD__
, $mode = self
::TRANSACTION_EXPLICIT
) {
3727 static $modes = [ self
::TRANSACTION_EXPLICIT
, self
::TRANSACTION_INTERNAL
];
3728 if ( !in_array( $mode, $modes, true ) ) {
3729 throw new DBUnexpectedError( $this, "$fname: invalid mode parameter '$mode'." );
3732 // Protect against mismatched atomic section, transaction nesting, and snapshot loss
3733 if ( $this->trxLevel
) {
3734 if ( $this->trxAtomicLevels
) {
3735 $levels = $this->flatAtomicSectionList();
3736 $msg = "$fname: Got explicit BEGIN while atomic section(s) $levels are open.";
3737 throw new DBUnexpectedError( $this, $msg );
3738 } elseif ( !$this->trxAutomatic
) {
3739 $msg = "$fname: Explicit transaction already active (from {$this->trxFname}).";
3740 throw new DBUnexpectedError( $this, $msg );
3742 $msg = "$fname: Implicit transaction already active (from {$this->trxFname}).";
3743 throw new DBUnexpectedError( $this, $msg );
3745 } elseif ( $this->getFlag( self
::DBO_TRX
) && $mode !== self
::TRANSACTION_INTERNAL
) {
3746 $msg = "$fname: Implicit transaction expected (DBO_TRX set).";
3747 throw new DBUnexpectedError( $this, $msg );
3750 // Avoid fatals if close() was called
3751 $this->assertOpen();
3753 $this->doBegin( $fname );
3754 $this->trxStatus
= self
::STATUS_TRX_OK
;
3755 $this->trxStatusIgnoredCause
= null;
3756 $this->trxAtomicCounter
= 0;
3757 $this->trxTimestamp
= microtime( true );
3758 $this->trxFname
= $fname;
3759 $this->trxDoneWrites
= false;
3760 $this->trxAutomaticAtomic
= false;
3761 $this->trxAtomicLevels
= [];
3762 $this->trxShortId
= sprintf( '%06x', mt_rand( 0, 0xffffff ) );
3763 $this->trxWriteDuration
= 0.0;
3764 $this->trxWriteQueryCount
= 0;
3765 $this->trxWriteAffectedRows
= 0;
3766 $this->trxWriteAdjDuration
= 0.0;
3767 $this->trxWriteAdjQueryCount
= 0;
3768 $this->trxWriteCallers
= [];
3769 // First SELECT after BEGIN will establish the snapshot in REPEATABLE-READ.
3770 // Get an estimate of the replication lag before any such queries.
3771 $this->trxReplicaLag
= null; // clear cached value first
3772 $this->trxReplicaLag
= $this->getApproximateLagStatus()['lag'];
3773 // T147697: make explicitTrxActive() return true until begin() finishes. This way, no
3774 // caller will think its OK to muck around with the transaction just because startAtomic()
3775 // has not yet completed (e.g. setting trxAtomicLevels).
3776 $this->trxAutomatic
= ( $mode === self
::TRANSACTION_INTERNAL
);
3780 * Issues the BEGIN command to the database server.
3782 * @see Database::begin()
3783 * @param string $fname
3785 protected function doBegin( $fname ) {
3786 $this->query( 'BEGIN', $fname );
3787 $this->trxLevel
= 1;
3790 final public function commit( $fname = __METHOD__
, $flush = self
::FLUSHING_ONE
) {
3791 static $modes = [ self
::FLUSHING_ONE
, self
::FLUSHING_ALL_PEERS
, self
::FLUSHING_INTERNAL
];
3792 if ( !in_array( $flush, $modes, true ) ) {
3793 throw new DBUnexpectedError( $this, "$fname: invalid flush parameter '$flush'." );
3796 if ( $this->trxLevel
&& $this->trxAtomicLevels
) {
3797 // There are still atomic sections open; this cannot be ignored
3798 $levels = $this->flatAtomicSectionList();
3799 throw new DBUnexpectedError(
3801 "$fname: Got COMMIT while atomic sections $levels are still open."
3805 if ( $flush === self
::FLUSHING_INTERNAL ||
$flush === self
::FLUSHING_ALL_PEERS
) {
3806 if ( !$this->trxLevel
) {
3807 return; // nothing to do
3808 } elseif ( !$this->trxAutomatic
) {
3809 throw new DBUnexpectedError(
3811 "$fname: Flushing an explicit transaction, getting out of sync."
3815 if ( !$this->trxLevel
) {
3816 $this->queryLogger
->error(
3817 "$fname: No transaction to commit, something got out of sync." );
3818 return; // nothing to do
3819 } elseif ( $this->trxAutomatic
) {
3820 throw new DBUnexpectedError(
3822 "$fname: Expected mass commit of all peer transactions (DBO_TRX set)."
3827 // Avoid fatals if close() was called
3828 $this->assertOpen();
3830 $this->runOnTransactionPreCommitCallbacks();
3831 $writeTime = $this->pendingWriteQueryDuration( self
::ESTIMATE_DB_APPLY
);
3832 $this->doCommit( $fname );
3833 $this->trxStatus
= self
::STATUS_TRX_NONE
;
3834 if ( $this->trxDoneWrites
) {
3835 $this->lastWriteTime
= microtime( true );
3836 $this->trxProfiler
->transactionWritingOut(
3841 $this->trxWriteAffectedRows
3845 // With FLUSHING_ALL_PEERS, callbacks will be explicitly run later
3846 if ( $flush !== self
::FLUSHING_ALL_PEERS
) {
3847 $this->runOnTransactionIdleCallbacks( self
::TRIGGER_COMMIT
);
3848 $this->runTransactionListenerCallbacks( self
::TRIGGER_COMMIT
);
3853 * Issues the COMMIT command to the database server.
3855 * @see Database::commit()
3856 * @param string $fname
3858 protected function doCommit( $fname ) {
3859 if ( $this->trxLevel
) {
3860 $this->query( 'COMMIT', $fname );
3861 $this->trxLevel
= 0;
3865 final public function rollback( $fname = __METHOD__
, $flush = '' ) {
3866 $trxActive = $this->trxLevel
;
3868 if ( $flush !== self
::FLUSHING_INTERNAL
&& $flush !== self
::FLUSHING_ALL_PEERS
) {
3869 if ( $this->getFlag( self
::DBO_TRX
) ) {
3870 throw new DBUnexpectedError(
3872 "$fname: Expected mass rollback of all peer transactions (DBO_TRX set)."
3878 // Avoid fatals if close() was called
3879 $this->assertOpen();
3881 $this->doRollback( $fname );
3882 $this->trxStatus
= self
::STATUS_TRX_NONE
;
3883 $this->trxAtomicLevels
= [];
3884 if ( $this->trxDoneWrites
) {
3885 $this->trxProfiler
->transactionWritingOut(
3893 // Clear any commit-dependant callbacks. They might even be present
3894 // only due to transaction rounds, with no SQL transaction being active
3895 $this->trxIdleCallbacks
= [];
3896 $this->trxPreCommitCallbacks
= [];
3898 // With FLUSHING_ALL_PEERS, callbacks will be explicitly run later
3899 if ( $trxActive && $flush !== self
::FLUSHING_ALL_PEERS
) {
3901 $this->runOnTransactionIdleCallbacks( self
::TRIGGER_ROLLBACK
);
3902 } catch ( Exception
$e ) {
3903 // already logged; finish and let LoadBalancer move on during mass-rollback
3906 $this->runTransactionListenerCallbacks( self
::TRIGGER_ROLLBACK
);
3907 } catch ( Exception
$e ) {
3908 // already logged; let LoadBalancer move on during mass-rollback
3911 $this->affectedRowCount
= 0; // for the sake of consistency
3916 * Issues the ROLLBACK command to the database server.
3918 * @see Database::rollback()
3919 * @param string $fname
3921 protected function doRollback( $fname ) {
3922 if ( $this->trxLevel
) {
3923 # Disconnects cause rollback anyway, so ignore those errors
3924 $ignoreErrors = true;
3925 $this->query( 'ROLLBACK', $fname, $ignoreErrors );
3926 $this->trxLevel
= 0;
3930 public function flushSnapshot( $fname = __METHOD__
) {
3931 if ( $this->writesOrCallbacksPending() ||
$this->explicitTrxActive() ) {
3932 // This only flushes transactions to clear snapshots, not to write data
3933 $fnames = implode( ', ', $this->pendingWriteAndCallbackCallers() );
3934 throw new DBUnexpectedError(
3936 "$fname: Cannot flush snapshot because writes are pending ($fnames)."
3940 $this->commit( $fname, self
::FLUSHING_INTERNAL
);
3943 public function explicitTrxActive() {
3944 return $this->trxLevel
&& ( $this->trxAtomicLevels ||
!$this->trxAutomatic
);
3947 public function duplicateTableStructure(
3948 $oldName, $newName, $temporary = false, $fname = __METHOD__
3950 throw new RuntimeException( __METHOD__
. ' is not implemented in descendant class' );
3953 public function listTables( $prefix = null, $fname = __METHOD__
) {
3954 throw new RuntimeException( __METHOD__
. ' is not implemented in descendant class' );
3957 public function listViews( $prefix = null, $fname = __METHOD__
) {
3958 throw new RuntimeException( __METHOD__
. ' is not implemented in descendant class' );
3961 public function timestamp( $ts = 0 ) {
3962 $t = new ConvertibleTimestamp( $ts );
3963 // Let errors bubble up to avoid putting garbage in the DB
3964 return $t->getTimestamp( TS_MW
);
3967 public function timestampOrNull( $ts = null ) {
3968 if ( is_null( $ts ) ) {
3971 return $this->timestamp( $ts );
3975 public function affectedRows() {
3976 return ( $this->affectedRowCount
=== null )
3977 ?
$this->fetchAffectedRowCount() // default to driver value
3978 : $this->affectedRowCount
;
3982 * @return int Number of retrieved rows according to the driver
3984 abstract protected function fetchAffectedRowCount();
3987 * Take the result from a query, and wrap it in a ResultWrapper if
3988 * necessary. Boolean values are passed through as is, to indicate success
3989 * of write queries or failure.
3991 * Once upon a time, Database::query() returned a bare MySQL result
3992 * resource, and it was necessary to call this function to convert it to
3993 * a wrapper. Nowadays, raw database objects are never exposed to external
3994 * callers, so this is unnecessary in external code.
3996 * @param bool|ResultWrapper|resource|object $result
3997 * @return bool|ResultWrapper
3999 protected function resultObject( $result ) {
4002 } elseif ( $result instanceof ResultWrapper
) {
4004 } elseif ( $result === true ) {
4005 // Successful write query
4008 return new ResultWrapper( $this, $result );
4012 public function ping( &$rtt = null ) {
4013 // Avoid hitting the server if it was hit recently
4014 if ( $this->isOpen() && ( microtime( true ) - $this->lastPing
) < self
::PING_TTL
) {
4015 if ( !func_num_args() ||
$this->rttEstimate
> 0 ) {
4016 $rtt = $this->rttEstimate
;
4017 return true; // don't care about $rtt
4021 // This will reconnect if possible or return false if not
4022 $this->clearFlag( self
::DBO_TRX
, self
::REMEMBER_PRIOR
);
4023 $ok = ( $this->query( self
::PING_QUERY
, __METHOD__
, true ) !== false );
4024 $this->restoreFlags( self
::RESTORE_PRIOR
);
4027 $rtt = $this->rttEstimate
;
4034 * Close any existing (dead) database connection and open a new connection
4036 * @param string $fname
4037 * @return bool True if new connection is opened successfully, false if error
4039 protected function replaceLostConnection( $fname ) {
4040 $this->closeConnection();
4041 $this->opened
= false;
4042 $this->conn
= false;
4044 $this->open( $this->server
, $this->user
, $this->password
, $this->dbName
);
4045 $this->lastPing
= microtime( true );
4048 $this->connLogger
->warning(
4049 $fname . ': lost connection to {dbserver}; reconnected',
4051 'dbserver' => $this->getServer(),
4052 'trace' => ( new RuntimeException() )->getTraceAsString()
4055 } catch ( DBConnectionError
$e ) {
4058 $this->connLogger
->error(
4059 $fname . ': lost connection to {dbserver} permanently',
4060 [ 'dbserver' => $this->getServer() ]
4064 $this->handleSessionLoss();
4069 public function getSessionLagStatus() {
4070 return $this->getRecordedTransactionLagStatus() ?
: $this->getApproximateLagStatus();
4074 * Get the replica DB lag when the current transaction started
4076 * This is useful when transactions might use snapshot isolation
4077 * (e.g. REPEATABLE-READ in innodb), so the "real" lag of that data
4078 * is this lag plus transaction duration. If they don't, it is still
4079 * safe to be pessimistic. This returns null if there is no transaction.
4081 * This returns null if the lag status for this transaction was not yet recorded.
4083 * @return array|null ('lag': seconds or false on error, 'since': UNIX timestamp of BEGIN)
4086 final protected function getRecordedTransactionLagStatus() {
4087 return ( $this->trxLevel
&& $this->trxReplicaLag
!== null )
4088 ?
[ 'lag' => $this->trxReplicaLag
, 'since' => $this->trxTimestamp() ]
4093 * Get a replica DB lag estimate for this server
4095 * @return array ('lag': seconds or false on error, 'since': UNIX timestamp of estimate)
4098 protected function getApproximateLagStatus() {
4100 'lag' => $this->getLBInfo( 'replica' ) ?
$this->getLag() : 0,
4101 'since' => microtime( true )
4106 * Merge the result of getSessionLagStatus() for several DBs
4107 * using the most pessimistic values to estimate the lag of
4108 * any data derived from them in combination
4110 * This is information is useful for caching modules
4112 * @see WANObjectCache::set()
4113 * @see WANObjectCache::getWithSetCallback()
4115 * @param IDatabase $db1
4116 * @param IDatabase|null $db2 [optional]
4117 * @return array Map of values:
4118 * - lag: highest lag of any of the DBs or false on error (e.g. replication stopped)
4119 * - since: oldest UNIX timestamp of any of the DB lag estimates
4120 * - pending: whether any of the DBs have uncommitted changes
4124 public static function getCacheSetOptions( IDatabase
$db1, IDatabase
$db2 = null ) {
4125 $res = [ 'lag' => 0, 'since' => INF
, 'pending' => false ];
4126 foreach ( func_get_args() as $db ) {
4127 /** @var IDatabase $db */
4128 $status = $db->getSessionLagStatus();
4129 if ( $status['lag'] === false ) {
4130 $res['lag'] = false;
4131 } elseif ( $res['lag'] !== false ) {
4132 $res['lag'] = max( $res['lag'], $status['lag'] );
4134 $res['since'] = min( $res['since'], $status['since'] );
4135 $res['pending'] = $res['pending'] ?
: $db->writesPending();
4141 public function getLag() {
4145 public function maxListLen() {
4149 public function encodeBlob( $b ) {
4153 public function decodeBlob( $b ) {
4154 if ( $b instanceof Blob
) {
4160 public function setSessionOptions( array $options ) {
4163 public function sourceFile(
4165 callable
$lineCallback = null,
4166 callable
$resultCallback = null,
4168 callable
$inputCallback = null
4170 Wikimedia\
suppressWarnings();
4171 $fp = fopen( $filename, 'r' );
4172 Wikimedia\restoreWarnings
();
4174 if ( false === $fp ) {
4175 throw new RuntimeException( "Could not open \"{$filename}\".\n" );
4179 $fname = __METHOD__
. "( $filename )";
4183 $error = $this->sourceStream(
4184 $fp, $lineCallback, $resultCallback, $fname, $inputCallback );
4185 } catch ( Exception
$e ) {
4195 public function setSchemaVars( $vars ) {
4196 $this->schemaVars
= $vars;
4199 public function sourceStream(
4201 callable
$lineCallback = null,
4202 callable
$resultCallback = null,
4203 $fname = __METHOD__
,
4204 callable
$inputCallback = null
4206 $delimiterReset = new ScopedCallback(
4207 function ( $delimiter ) {
4208 $this->delimiter
= $delimiter;
4210 [ $this->delimiter
]
4214 while ( !feof( $fp ) ) {
4215 if ( $lineCallback ) {
4216 call_user_func( $lineCallback );
4219 $line = trim( fgets( $fp ) );
4221 if ( $line == '' ) {
4225 if ( '-' == $line[0] && '-' == $line[1] ) {
4233 $done = $this->streamStatementEnd( $cmd, $line );
4237 if ( $done ||
feof( $fp ) ) {
4238 $cmd = $this->replaceVars( $cmd );
4240 if ( $inputCallback ) {
4241 $callbackResult = $inputCallback( $cmd );
4243 if ( is_string( $callbackResult ) ||
!$callbackResult ) {
4244 $cmd = $callbackResult;
4249 $res = $this->query( $cmd, $fname );
4251 if ( $resultCallback ) {
4252 $resultCallback( $res, $this );
4255 if ( false === $res ) {
4256 $err = $this->lastError();
4258 return "Query \"{$cmd}\" failed with error code \"$err\".\n";
4265 ScopedCallback
::consume( $delimiterReset );
4270 * Called by sourceStream() to check if we've reached a statement end
4272 * @param string &$sql SQL assembled so far
4273 * @param string &$newLine New line about to be added to $sql
4274 * @return bool Whether $newLine contains end of the statement
4276 public function streamStatementEnd( &$sql, &$newLine ) {
4277 if ( $this->delimiter
) {
4279 $newLine = preg_replace(
4280 '/' . preg_quote( $this->delimiter
, '/' ) . '$/', '', $newLine );
4281 if ( $newLine != $prev ) {
4290 * Database independent variable replacement. Replaces a set of variables
4291 * in an SQL statement with their contents as given by $this->getSchemaVars().
4293 * Supports '{$var}' `{$var}` and / *$var* / (without the spaces) style variables.
4295 * - '{$var}' should be used for text and is passed through the database's
4297 * - `{$var}` should be used for identifiers (e.g. table and database names).
4298 * It is passed through the database's addIdentifierQuotes method which
4299 * can be overridden if the database uses something other than backticks.
4300 * - / *_* / or / *$wgDBprefix* / passes the name that follows through the
4301 * database's tableName method.
4302 * - / *i* / passes the name that follows through the database's indexName method.
4303 * - In all other cases, / *$var* / is left unencoded. Except for table options,
4304 * its use should be avoided. In 1.24 and older, string encoding was applied.
4306 * @param string $ins SQL statement to replace variables in
4307 * @return string The new SQL statement with variables replaced
4309 protected function replaceVars( $ins ) {
4310 $vars = $this->getSchemaVars();
4311 return preg_replace_callback(
4313 /\* (\$wgDBprefix|[_i]) \*/ (\w*) | # 1-2. tableName, indexName
4314 \'\{\$ (\w+) }\' | # 3. addQuotes
4315 `\{\$ (\w+) }` | # 4. addIdentifierQuotes
4316 /\*\$ (\w+) \*/ # 5. leave unencoded
4318 function ( $m ) use ( $vars ) {
4319 // Note: Because of <https://bugs.php.net/bug.php?id=51881>,
4320 // check for both nonexistent keys *and* the empty string.
4321 if ( isset( $m[1] ) && $m[1] !== '' ) {
4322 if ( $m[1] === 'i' ) {
4323 return $this->indexName( $m[2] );
4325 return $this->tableName( $m[2] );
4327 } elseif ( isset( $m[3] ) && $m[3] !== '' && array_key_exists( $m[3], $vars ) ) {
4328 return $this->addQuotes( $vars[$m[3]] );
4329 } elseif ( isset( $m[4] ) && $m[4] !== '' && array_key_exists( $m[4], $vars ) ) {
4330 return $this->addIdentifierQuotes( $vars[$m[4]] );
4331 } elseif ( isset( $m[5] ) && $m[5] !== '' && array_key_exists( $m[5], $vars ) ) {
4332 return $vars[$m[5]];
4342 * Get schema variables. If none have been set via setSchemaVars(), then
4343 * use some defaults from the current object.
4347 protected function getSchemaVars() {
4348 if ( $this->schemaVars
) {
4349 return $this->schemaVars
;
4351 return $this->getDefaultSchemaVars();
4356 * Get schema variables to use if none have been set via setSchemaVars().
4358 * Override this in derived classes to provide variables for tables.sql
4359 * and SQL patch files.
4363 protected function getDefaultSchemaVars() {
4367 public function lockIsFree( $lockName, $method ) {
4368 // RDBMs methods for checking named locks may or may not count this thread itself.
4369 // In MySQL, IS_FREE_LOCK() returns 0 if the thread already has the lock. This is
4370 // the behavior choosen by the interface for this method.
4371 return !isset( $this->namedLocksHeld
[$lockName] );
4374 public function lock( $lockName, $method, $timeout = 5 ) {
4375 $this->namedLocksHeld
[$lockName] = 1;
4380 public function unlock( $lockName, $method ) {
4381 unset( $this->namedLocksHeld
[$lockName] );
4386 public function getScopedLockAndFlush( $lockKey, $fname, $timeout ) {
4387 if ( $this->writesOrCallbacksPending() ) {
4388 // This only flushes transactions to clear snapshots, not to write data
4389 $fnames = implode( ', ', $this->pendingWriteAndCallbackCallers() );
4390 throw new DBUnexpectedError(
4392 "$fname: Cannot flush pre-lock snapshot because writes are pending ($fnames)."
4396 if ( !$this->lock( $lockKey, $fname, $timeout ) ) {
4400 $unlocker = new ScopedCallback( function () use ( $lockKey, $fname ) {
4401 if ( $this->trxLevel() ) {
4402 // There is a good chance an exception was thrown, causing any early return
4403 // from the caller. Let any error handler get a chance to issue rollback().
4404 // If there isn't one, let the error bubble up and trigger server-side rollback.
4405 $this->onTransactionResolution(
4406 function () use ( $lockKey, $fname ) {
4407 $this->unlock( $lockKey, $fname );
4412 $this->unlock( $lockKey, $fname );
4416 $this->commit( $fname, self
::FLUSHING_INTERNAL
);
4421 public function namedLocksEnqueue() {
4425 public function tableLocksHaveTransactionScope() {
4429 final public function lockTables( array $read, array $write, $method ) {
4430 if ( $this->writesOrCallbacksPending() ) {
4431 throw new DBUnexpectedError( $this, "Transaction writes or callbacks still pending." );
4434 if ( $this->tableLocksHaveTransactionScope() ) {
4435 $this->startAtomic( $method );
4438 return $this->doLockTables( $read, $write, $method );
4442 * Helper function for lockTables() that handles the actual table locking
4444 * @param array $read Array of tables to lock for read access
4445 * @param array $write Array of tables to lock for write access
4446 * @param string $method Name of caller
4449 protected function doLockTables( array $read, array $write, $method ) {
4453 final public function unlockTables( $method ) {
4454 if ( $this->tableLocksHaveTransactionScope() ) {
4455 $this->endAtomic( $method );
4457 return true; // locks released on COMMIT/ROLLBACK
4460 return $this->doUnlockTables( $method );
4464 * Helper function for unlockTables() that handles the actual table unlocking
4466 * @param string $method Name of caller
4469 protected function doUnlockTables( $method ) {
4475 * @param string $tableName
4476 * @param string $fName
4477 * @return bool|ResultWrapper
4480 public function dropTable( $tableName, $fName = __METHOD__
) {
4481 if ( !$this->tableExists( $tableName, $fName ) ) {
4484 $sql = "DROP TABLE " . $this->tableName( $tableName ) . " CASCADE";
4486 return $this->query( $sql, $fName );
4489 public function getInfinity() {
4493 public function encodeExpiry( $expiry ) {
4494 return ( $expiry == '' ||
$expiry == 'infinity' ||
$expiry == $this->getInfinity() )
4495 ?
$this->getInfinity()
4496 : $this->timestamp( $expiry );
4499 public function decodeExpiry( $expiry, $format = TS_MW
) {
4500 if ( $expiry == '' ||
$expiry == 'infinity' ||
$expiry == $this->getInfinity() ) {
4504 return ConvertibleTimestamp
::convert( $format, $expiry );
4507 public function setBigSelects( $value = true ) {
4511 public function isReadOnly() {
4512 return ( $this->getReadOnlyReason() !== false );
4516 * @return string|bool Reason this DB is read-only or false if it is not
4518 protected function getReadOnlyReason() {
4519 $reason = $this->getLBInfo( 'readOnlyReason' );
4521 return is_string( $reason ) ?
$reason : false;
4524 public function setTableAliases( array $aliases ) {
4525 $this->tableAliases
= $aliases;
4528 public function setIndexAliases( array $aliases ) {
4529 $this->indexAliases
= $aliases;
4533 * Get the underlying binding connection handle
4535 * Makes sure the connection resource is set (disconnects and ping() failure can unset it).
4536 * This catches broken callers than catch and ignore disconnection exceptions.
4537 * Unlike checking isOpen(), this is safe to call inside of open().
4540 * @throws DBUnexpectedError
4543 protected function getBindingHandle() {
4544 if ( !$this->conn
) {
4545 throw new DBUnexpectedError(
4547 'DB connection was already closed or the connection dropped.'
4558 public function __toString() {
4559 return (string)$this->conn
;
4563 * Make sure that copies do not share the same client binding handle
4564 * @throws DBConnectionError
4566 public function __clone() {
4567 $this->connLogger
->warning(
4568 "Cloning " . static::class . " is not recomended; forking connection:\n" .
4569 ( new RuntimeException() )->getTraceAsString()
4572 if ( $this->isOpen() ) {
4573 // Open a new connection resource without messing with the old one
4574 $this->opened
= false;
4575 $this->conn
= false;
4576 $this->trxEndCallbacks
= []; // don't copy
4577 $this->handleSessionLoss(); // no trx or locks anymore
4578 $this->open( $this->server
, $this->user
, $this->password
, $this->dbName
);
4579 $this->lastPing
= microtime( true );
4584 * Called by serialize. Throw an exception when DB connection is serialized.
4585 * This causes problems on some database engines because the connection is
4586 * not restored on unserialize.
4588 public function __sleep() {
4589 throw new RuntimeException( 'Database serialization may cause problems, since ' .
4590 'the connection is not restored on wakeup.' );
4594 * Run a few simple sanity checks and close dangling connections
4596 public function __destruct() {
4597 if ( $this->trxLevel
&& $this->trxDoneWrites
) {
4598 trigger_error( "Uncommitted DB writes (transaction from {$this->trxFname})." );
4601 $danglingWriters = $this->pendingWriteAndCallbackCallers();
4602 if ( $danglingWriters ) {
4603 $fnames = implode( ', ', $danglingWriters );
4604 trigger_error( "DB transaction writes or callbacks still pending ($fnames)." );
4607 if ( $this->conn
) {
4608 // Avoid connection leaks for sanity. Normally, resources close at script completion.
4609 // The connection might already be closed in zend/hhvm by now, so suppress warnings.
4610 Wikimedia\
suppressWarnings();
4611 $this->closeConnection();
4612 Wikimedia\restoreWarnings
();
4613 $this->conn
= false;
4614 $this->opened
= false;
4620 * @deprecated since 1.28
4622 class_alias( Database
::class, 'DatabaseBase' );
4625 * @deprecated since 1.29
4627 class_alias( Database
::class, 'Database' );