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 array[] Map of (table => (dbname, schema, prefix) map) */
85 protected $tableAliases = [];
86 /** @var string[] Map of (index alias => index) */
87 protected $indexAliases = [];
88 /** @var bool Whether this PHP instance is for a CLI script */
90 /** @var string Agent name for query profiling */
92 /** @var array Parameters used by initConnection() to establish a connection */
93 protected $connectionParams = [];
94 /** @var BagOStuff APC cache */
96 /** @var LoggerInterface */
97 protected $connLogger;
98 /** @var LoggerInterface */
99 protected $queryLogger;
100 /** @var callback Error logging callback */
101 protected $errorLogger;
102 /** @var callback Deprecation logging callback */
103 protected $deprecationLogger;
105 /** @var resource|null Database connection */
106 protected $conn = null;
108 protected $opened = false;
110 /** @var array[] List of (callable, method name, atomic section id) */
111 protected $trxIdleCallbacks = [];
112 /** @var array[] List of (callable, method name, atomic section id) */
113 protected $trxPreCommitCallbacks = [];
114 /** @var array[] List of (callable, method name, atomic section id) */
115 protected $trxEndCallbacks = [];
116 /** @var callable[] Map of (name => callable) */
117 protected $trxRecurringCallbacks = [];
118 /** @var bool Whether to suppress triggering of transaction end callbacks */
119 protected $trxEndCallbacksSuppressed = false;
124 protected $lbInfo = [];
125 /** @var array|bool */
126 protected $schemaVars = false;
128 protected $sessionVars = [];
129 /** @var array|null */
130 protected $preparedArgs;
131 /** @var string|bool|null Stashed value of html_errors INI setting */
132 protected $htmlErrors;
134 protected $delimiter = ';';
135 /** @var DatabaseDomain */
136 protected $currentDomain;
137 /** @var integer|null Rows affected by the last query to query() or its CRUD wrappers */
138 protected $affectedRowCount;
141 * @var int Transaction status
143 protected $trxStatus = self
::STATUS_TRX_NONE
;
145 * @var Exception|null The last error that caused the status to become STATUS_TRX_ERROR
147 protected $trxStatusCause;
149 * @var array|null If wasKnownStatementRollbackError() prevented trxStatus from being set,
150 * the relevant details are stored here.
152 protected $trxStatusIgnoredCause;
154 * Either 1 if a transaction is active or 0 otherwise.
155 * The other Trx fields may not be meaningfull if this is 0.
159 protected $trxLevel = 0;
161 * Either a short hexidecimal string if a transaction is active or ""
164 * @see Database::trxLevel
166 protected $trxShortId = '';
168 * The UNIX time that the transaction started. Callers can assume that if
169 * snapshot isolation is used, then the data is *at least* up to date to that
170 * point (possibly more up-to-date since the first SELECT defines the snapshot).
173 * @see Database::trxLevel
175 private $trxTimestamp = null;
176 /** @var float Lag estimate at the time of BEGIN */
177 private $trxReplicaLag = null;
179 * Remembers the function name given for starting the most recent transaction via begin().
180 * Used to provide additional context for error reporting.
183 * @see Database::trxLevel
185 private $trxFname = null;
187 * Record if possible write queries were done in the last transaction started
190 * @see Database::trxLevel
192 private $trxDoneWrites = false;
194 * Record if the current transaction was started implicitly due to DBO_TRX being set.
197 * @see Database::trxLevel
199 private $trxAutomatic = false;
201 * Counter for atomic savepoint identifiers. Reset when a new transaction begins.
205 private $trxAtomicCounter = 0;
207 * Array of levels of atomicity within transactions
209 * @var array List of (name, unique ID, savepoint ID)
211 private $trxAtomicLevels = [];
213 * Record if the current transaction was started implicitly by Database::startAtomic
217 private $trxAutomaticAtomic = false;
219 * Track the write query callers of the current transaction
223 private $trxWriteCallers = [];
225 * @var float Seconds spent in write queries for the current transaction
227 private $trxWriteDuration = 0.0;
229 * @var int Number of write queries for the current transaction
231 private $trxWriteQueryCount = 0;
233 * @var int Number of rows affected by write queries for the current transaction
235 private $trxWriteAffectedRows = 0;
237 * @var float Like trxWriteQueryCount but excludes lock-bound, easy to replicate, queries
239 private $trxWriteAdjDuration = 0.0;
241 * @var int Number of write queries counted in trxWriteAdjDuration
243 private $trxWriteAdjQueryCount = 0;
245 * @var float RTT time estimate
247 private $rttEstimate = 0.0;
249 /** @var array Map of (name => 1) for locks obtained via lock() */
250 private $namedLocksHeld = [];
251 /** @var array Map of (table name => 1) for TEMPORARY tables */
252 protected $sessionTempTables = [];
254 /** @var IDatabase|null Lazy handle to the master DB this server replicates from */
255 private $lazyMasterHandle;
257 /** @var float UNIX timestamp */
258 protected $lastPing = 0.0;
260 /** @var int[] Prior flags member variable values */
261 private $priorFlags = [];
263 /** @var mixed Class name or object With profileIn/profileOut methods */
265 /** @var TransactionProfiler */
266 protected $trxProfiler;
269 protected $nonNativeInsertSelectBatchSize = 10000;
271 /** @var string Idiom used when a cancelable atomic section started the transaction */
272 private static $NOT_APPLICABLE = 'n/a';
273 /** @var string Prefix to the atomic section counter used to make savepoint IDs */
274 private static $SAVEPOINT_PREFIX = 'wikimedia_rdbms_atomic';
276 /** @var int Transaction is in a error state requiring a full or savepoint rollback */
277 const STATUS_TRX_ERROR
= 1;
278 /** @var int Transaction is active and in a normal state */
279 const STATUS_TRX_OK
= 2;
280 /** @var int No transaction is active */
281 const STATUS_TRX_NONE
= 3;
284 * @note exceptions for missing libraries/drivers should be thrown in initConnection()
285 * @param array $params Parameters passed from Database::factory()
287 protected function __construct( array $params ) {
288 foreach ( [ 'host', 'user', 'password', 'dbname', 'schema', 'tablePrefix' ] as $name ) {
289 $this->connectionParams
[$name] = $params[$name];
292 $this->cliMode
= $params['cliMode'];
293 // Agent name is added to SQL queries in a comment, so make sure it can't break out
294 $this->agent
= str_replace( '/', '-', $params['agent'] );
296 $this->flags
= $params['flags'];
297 if ( $this->flags
& self
::DBO_DEFAULT
) {
298 if ( $this->cliMode
) {
299 $this->flags
&= ~self
::DBO_TRX
;
301 $this->flags |
= self
::DBO_TRX
;
304 // Disregard deprecated DBO_IGNORE flag (T189999)
305 $this->flags
&= ~self
::DBO_IGNORE
;
307 $this->sessionVars
= $params['variables'];
309 $this->srvCache
= $params['srvCache'] ??
new HashBagOStuff();
311 $this->profiler
= $params['profiler'];
312 $this->trxProfiler
= $params['trxProfiler'];
313 $this->connLogger
= $params['connLogger'];
314 $this->queryLogger
= $params['queryLogger'];
315 $this->errorLogger
= $params['errorLogger'];
316 $this->deprecationLogger
= $params['deprecationLogger'];
318 if ( isset( $params['nonNativeInsertSelectBatchSize'] ) ) {
319 $this->nonNativeInsertSelectBatchSize
= $params['nonNativeInsertSelectBatchSize'];
322 // Set initial dummy domain until open() sets the final DB/prefix
323 $this->currentDomain
= new DatabaseDomain(
324 $params['dbname'] != '' ?
$params['dbname'] : null,
325 $params['schema'] != '' ?
$params['schema'] : null,
326 $params['tablePrefix']
331 * Initialize the connection to the database over the wire (or to local files)
333 * @throws LogicException
334 * @throws InvalidArgumentException
335 * @throws DBConnectionError
338 final public function initConnection() {
339 if ( $this->isOpen() ) {
340 throw new LogicException( __METHOD__
. ': already connected.' );
342 // Establish the connection
343 $this->doInitConnection();
347 * Actually connect to the database over the wire (or to local files)
349 * @throws InvalidArgumentException
350 * @throws DBConnectionError
353 protected function doInitConnection() {
354 if ( strlen( $this->connectionParams
['user'] ) ) {
356 $this->connectionParams
['host'],
357 $this->connectionParams
['user'],
358 $this->connectionParams
['password'],
359 $this->connectionParams
['dbname'],
360 $this->connectionParams
['schema'],
361 $this->connectionParams
['tablePrefix']
364 throw new InvalidArgumentException( "No database user provided." );
369 * Open a new connection to the database (closing any existing one)
371 * @param string $server Database server host
372 * @param string $user Database user name
373 * @param string $password Database user password
374 * @param string $dbName Database name
375 * @param string|null $schema Database schema name
376 * @param string $tablePrefix Table prefix
378 * @throws DBConnectionError
380 abstract protected function open( $server, $user, $password, $dbName, $schema, $tablePrefix );
383 * Construct a Database subclass instance given a database type and parameters
385 * This also connects to the database immediately upon object construction
387 * @param string $dbType A possible DB type (sqlite, mysql, postgres,...)
388 * @param array $p Parameter map with keys:
389 * - host : The hostname of the DB server
390 * - user : The name of the database user the client operates under
391 * - password : The password for the database user
392 * - dbname : The name of the database to use where queries do not specify one.
393 * The database must exist or an error might be thrown. Setting this to the empty string
394 * will avoid any such errors and make the handle have no implicit database scope. This is
395 * useful for queries like SHOW STATUS, CREATE DATABASE, or DROP DATABASE. Note that a
396 * "database" in Postgres is rougly equivalent to an entire MySQL server. This the domain
397 * in which user names and such are defined, e.g. users are database-specific in Postgres.
398 * - schema : The database schema to use (if supported). A "schema" in Postgres is roughly
399 * equivalent to a "database" in MySQL. Note that MySQL and SQLite do not use schemas.
400 * - tablePrefix : Optional table prefix that is implicitly added on to all table names
401 * recognized in queries. This can be used in place of schemas for handle site farms.
402 * - flags : Optional bitfield of DBO_* constants that define connection, protocol,
403 * buffering, and transaction behavior. It is STRONGLY adviced to leave the DBO_DEFAULT
404 * flag in place UNLESS this this database simply acts as a key/value store.
405 * - driver: Optional name of a specific DB client driver. For MySQL, there is only the
406 * 'mysqli' driver; the old one 'mysql' has been removed.
407 * - variables: Optional map of session variables to set after connecting. This can be
408 * used to adjust lock timeouts or encoding modes and the like.
409 * - connLogger: Optional PSR-3 logger interface instance.
410 * - queryLogger: Optional PSR-3 logger interface instance.
411 * - profiler: Optional class name or object with profileIn()/profileOut() methods.
412 * These will be called in query(), using a simplified version of the SQL that also
413 * includes the agent as a SQL comment.
414 * - trxProfiler: Optional TransactionProfiler instance.
415 * - errorLogger: Optional callback that takes an Exception and logs it.
416 * - deprecationLogger: Optional callback that takes a string and logs it.
417 * - cliMode: Whether to consider the execution context that of a CLI script.
418 * - agent: Optional name used to identify the end-user in query profiling/logging.
419 * - srvCache: Optional BagOStuff instance to an APC-style cache.
420 * - nonNativeInsertSelectBatchSize: Optional batch size for non-native INSERT SELECT emulation.
421 * @param int $connect One of the class constants (NEW_CONNECTED, NEW_UNCONNECTED) [optional]
422 * @return Database|null If the database driver or extension cannot be found
423 * @throws InvalidArgumentException If the database driver or extension cannot be found
426 final public static function factory( $dbType, $p = [], $connect = self
::NEW_CONNECTED
) {
427 $class = self
::getClass( $dbType, $p['driver'] ??
null );
429 if ( class_exists( $class ) && is_subclass_of( $class, IDatabase
::class ) ) {
430 // Resolve some defaults for b/c
431 $p['host'] = $p['host'] ??
false;
432 $p['user'] = $p['user'] ??
false;
433 $p['password'] = $p['password'] ??
false;
434 $p['dbname'] = $p['dbname'] ??
false;
435 $p['flags'] = $p['flags'] ??
0;
436 $p['variables'] = $p['variables'] ??
[];
437 $p['tablePrefix'] = $p['tablePrefix'] ??
'';
438 $p['schema'] = $p['schema'] ??
null;
439 $p['cliMode'] = $p['cliMode'] ??
( PHP_SAPI
=== 'cli' || PHP_SAPI
=== 'phpdbg' );
440 $p['agent'] = $p['agent'] ??
'';
441 if ( !isset( $p['connLogger'] ) ) {
442 $p['connLogger'] = new NullLogger();
444 if ( !isset( $p['queryLogger'] ) ) {
445 $p['queryLogger'] = new NullLogger();
447 $p['profiler'] = $p['profiler'] ??
null;
448 if ( !isset( $p['trxProfiler'] ) ) {
449 $p['trxProfiler'] = new TransactionProfiler();
451 if ( !isset( $p['errorLogger'] ) ) {
452 $p['errorLogger'] = function ( Exception
$e ) {
453 trigger_error( get_class( $e ) . ': ' . $e->getMessage(), E_USER_WARNING
);
456 if ( !isset( $p['deprecationLogger'] ) ) {
457 $p['deprecationLogger'] = function ( $msg ) {
458 trigger_error( $msg, E_USER_DEPRECATED
);
462 /** @var Database $conn */
463 $conn = new $class( $p );
464 if ( $connect == self
::NEW_CONNECTED
) {
465 $conn->initConnection();
475 * @param string $dbType A possible DB type (sqlite, mysql, postgres,...)
476 * @param string|null $driver Optional name of a specific DB client driver
477 * @return array Map of (Database::ATTRIBUTE_* constant => value) for all such constants
478 * @throws InvalidArgumentException
481 final public static function attributesFromType( $dbType, $driver = null ) {
482 static $defaults = [ self
::ATTR_DB_LEVEL_LOCKING
=> false ];
484 $class = self
::getClass( $dbType, $driver );
486 return call_user_func( [ $class, 'getAttributes' ] ) +
$defaults;
490 * @param string $dbType A possible DB type (sqlite, mysql, postgres,...)
491 * @param string|null $driver Optional name of a specific DB client driver
492 * @return string Database subclass name to use
493 * @throws InvalidArgumentException
495 private static function getClass( $dbType, $driver = null ) {
496 // For database types with built-in support, the below maps type to IDatabase
497 // implementations. For types with multipe driver implementations (PHP extensions),
498 // an array can be used, keyed by extension name. In case of an array, the
499 // optional 'driver' parameter can be used to force a specific driver. Otherwise,
500 // we auto-detect the first available driver. For types without built-in support,
501 // an class named "Database<Type>" us used, eg. DatabaseFoo for type 'foo'.
502 static $builtinTypes = [
503 'mssql' => DatabaseMssql
::class,
504 'mysql' => [ 'mysqli' => DatabaseMysqli
::class ],
505 'sqlite' => DatabaseSqlite
::class,
506 'postgres' => DatabasePostgres
::class,
509 $dbType = strtolower( $dbType );
512 if ( isset( $builtinTypes[$dbType] ) ) {
513 $possibleDrivers = $builtinTypes[$dbType];
514 if ( is_string( $possibleDrivers ) ) {
515 $class = $possibleDrivers;
517 if ( (string)$driver !== '' ) {
518 if ( !isset( $possibleDrivers[$driver] ) ) {
519 throw new InvalidArgumentException( __METHOD__
.
520 " type '$dbType' does not support driver '{$driver}'" );
522 $class = $possibleDrivers[$driver];
525 foreach ( $possibleDrivers as $posDriver => $possibleClass ) {
526 if ( extension_loaded( $posDriver ) ) {
527 $class = $possibleClass;
534 $class = 'Database' . ucfirst( $dbType );
537 if ( $class === false ) {
538 throw new InvalidArgumentException( __METHOD__
.
539 " no viable database extension found for type '$dbType'" );
546 * @return array Map of (Database::ATTRIBUTE_* constant => value
549 protected static function getAttributes() {
554 * Set the PSR-3 logger interface to use for query logging. (The logger
555 * interfaces for connection logging and error logging can be set with the
558 * @param LoggerInterface $logger
560 public function setLogger( LoggerInterface
$logger ) {
561 $this->queryLogger
= $logger;
564 public function getServerInfo() {
565 return $this->getServerVersion();
568 public function bufferResults( $buffer = null ) {
569 $res = !$this->getFlag( self
::DBO_NOBUFFER
);
570 if ( $buffer !== null ) {
572 ?
$this->clearFlag( self
::DBO_NOBUFFER
)
573 : $this->setFlag( self
::DBO_NOBUFFER
);
579 public function trxLevel() {
580 return $this->trxLevel
;
583 public function trxTimestamp() {
584 return $this->trxLevel ?
$this->trxTimestamp
: null;
588 * @return int One of the STATUS_TRX_* class constants
591 public function trxStatus() {
592 return $this->trxStatus
;
595 public function tablePrefix( $prefix = null ) {
596 $old = $this->currentDomain
->getTablePrefix();
597 if ( $prefix !== null ) {
598 $this->currentDomain
= new DatabaseDomain(
599 $this->currentDomain
->getDatabase(),
600 $this->currentDomain
->getSchema(),
608 public function dbSchema( $schema = null ) {
609 $old = $this->currentDomain
->getSchema();
610 if ( $schema !== null ) {
611 $this->currentDomain
= new DatabaseDomain(
612 $this->currentDomain
->getDatabase(),
613 // DatabaseDomain uses null for unspecified schemas
614 strlen( $schema ) ?
$schema : null,
615 $this->currentDomain
->getTablePrefix()
623 * @return string Schema to use to qualify relations in queries
625 protected function relationSchemaQualifier() {
626 return $this->dbSchema();
629 public function getLBInfo( $name = null ) {
630 if ( is_null( $name ) ) {
631 return $this->lbInfo
;
633 if ( array_key_exists( $name, $this->lbInfo
) ) {
634 return $this->lbInfo
[$name];
641 public function setLBInfo( $name, $value = null ) {
642 if ( is_null( $value ) ) {
643 $this->lbInfo
= $name;
645 $this->lbInfo
[$name] = $value;
649 public function setLazyMasterHandle( IDatabase
$conn ) {
650 $this->lazyMasterHandle
= $conn;
654 * @return IDatabase|null
655 * @see setLazyMasterHandle()
658 protected function getLazyMasterHandle() {
659 return $this->lazyMasterHandle
;
662 public function implicitGroupby() {
666 public function implicitOrderby() {
670 public function lastQuery() {
671 return $this->lastQuery
;
674 public function doneWrites() {
675 return (bool)$this->lastWriteTime
;
678 public function lastDoneWrites() {
679 return $this->lastWriteTime ?
: false;
682 public function writesPending() {
683 return $this->trxLevel
&& $this->trxDoneWrites
;
686 public function writesOrCallbacksPending() {
687 return $this->trxLevel
&& (
688 $this->trxDoneWrites ||
689 $this->trxIdleCallbacks ||
690 $this->trxPreCommitCallbacks ||
691 $this->trxEndCallbacks
695 public function preCommitCallbacksPending() {
696 return $this->trxLevel
&& $this->trxPreCommitCallbacks
;
700 * @return string|null
702 final protected function getTransactionRoundId() {
703 // If transaction round participation is enabled, see if one is active
704 if ( $this->getFlag( self
::DBO_TRX
) ) {
705 $id = $this->getLBInfo( 'trxRoundId' );
707 return is_string( $id ) ?
$id : null;
713 public function pendingWriteQueryDuration( $type = self
::ESTIMATE_TOTAL
) {
714 if ( !$this->trxLevel
) {
716 } elseif ( !$this->trxDoneWrites
) {
721 case self
::ESTIMATE_DB_APPLY
:
723 $rttAdjTotal = $this->trxWriteAdjQueryCount
* $rtt;
724 $applyTime = max( $this->trxWriteAdjDuration
- $rttAdjTotal, 0 );
725 // For omitted queries, make them count as something at least
726 $omitted = $this->trxWriteQueryCount
- $this->trxWriteAdjQueryCount
;
727 $applyTime +
= self
::TINY_WRITE_SEC
* $omitted;
730 default: // everything
731 return $this->trxWriteDuration
;
735 public function pendingWriteCallers() {
736 return $this->trxLevel ?
$this->trxWriteCallers
: [];
739 public function pendingWriteRowsAffected() {
740 return $this->trxWriteAffectedRows
;
744 * List the methods that have write queries or callbacks for the current transaction
746 * This method should not be used outside of Database/LoadBalancer
751 public function pendingWriteAndCallbackCallers() {
752 $fnames = $this->pendingWriteCallers();
754 $this->trxIdleCallbacks
,
755 $this->trxPreCommitCallbacks
,
756 $this->trxEndCallbacks
758 foreach ( $callbacks as $callback ) {
759 $fnames[] = $callback[1];
769 private function flatAtomicSectionList() {
770 return array_reduce( $this->trxAtomicLevels
, function ( $accum, $v ) {
771 return $accum === null ?
$v[0] : "$accum, " . $v[0];
775 public function isOpen() {
776 return $this->opened
;
779 public function setFlag( $flag, $remember = self
::REMEMBER_NOTHING
) {
780 if ( ( $flag & self
::DBO_IGNORE
) ) {
781 throw new UnexpectedValueException( "Modifying DBO_IGNORE is not allowed." );
784 if ( $remember === self
::REMEMBER_PRIOR
) {
785 array_push( $this->priorFlags
, $this->flags
);
787 $this->flags |
= $flag;
790 public function clearFlag( $flag, $remember = self
::REMEMBER_NOTHING
) {
791 if ( ( $flag & self
::DBO_IGNORE
) ) {
792 throw new UnexpectedValueException( "Modifying DBO_IGNORE is not allowed." );
795 if ( $remember === self
::REMEMBER_PRIOR
) {
796 array_push( $this->priorFlags
, $this->flags
);
798 $this->flags
&= ~
$flag;
801 public function restoreFlags( $state = self
::RESTORE_PRIOR
) {
802 if ( !$this->priorFlags
) {
806 if ( $state === self
::RESTORE_INITIAL
) {
807 $this->flags
= reset( $this->priorFlags
);
808 $this->priorFlags
= [];
810 $this->flags
= array_pop( $this->priorFlags
);
814 public function getFlag( $flag ) {
815 return !!( $this->flags
& $flag );
819 * @param string $name Class field name
821 * @deprecated Since 1.28
823 public function getProperty( $name ) {
827 public function getDomainID() {
828 return $this->currentDomain
->getId();
831 final public function getWikiID() {
832 return $this->getDomainID();
836 * Get information about an index into an object
837 * @param string $table Table name
838 * @param string $index Index name
839 * @param string $fname Calling function name
840 * @return mixed Database-specific index description class or false if the index does not exist
842 abstract function indexInfo( $table, $index, $fname = __METHOD__
);
845 * Wrapper for addslashes()
847 * @param string $s String to be slashed.
848 * @return string Slashed string.
850 abstract function strencode( $s );
853 * Set a custom error handler for logging errors during database connection
855 protected function installErrorHandler() {
856 $this->phpError
= false;
857 $this->htmlErrors
= ini_set( 'html_errors', '0' );
858 set_error_handler( [ $this, 'connectionErrorLogger' ] );
862 * Restore the previous error handler and return the last PHP error for this DB
864 * @return bool|string
866 protected function restoreErrorHandler() {
867 restore_error_handler();
868 if ( $this->htmlErrors
!== false ) {
869 ini_set( 'html_errors', $this->htmlErrors
);
872 return $this->getLastPHPError();
876 * @return string|bool Last PHP error for this DB (typically connection errors)
878 protected function getLastPHPError() {
879 if ( $this->phpError
) {
880 $error = preg_replace( '!\[<a.*</a>\]!', '', $this->phpError
);
881 $error = preg_replace( '!^.*?:\s?(.*)$!', '$1', $error );
890 * Error handler for logging errors during database connection
891 * This method should not be used outside of Database classes
894 * @param string $errstr
896 public function connectionErrorLogger( $errno, $errstr ) {
897 $this->phpError
= $errstr;
901 * Create a log context to pass to PSR-3 logger functions.
903 * @param array $extras Additional data to add to context
906 protected function getLogContext( array $extras = [] ) {
909 'db_server' => $this->server
,
910 'db_name' => $this->getDBname(),
911 'db_user' => $this->user
,
917 final public function close() {
918 $exception = null; // error to throw after disconnecting
921 // Roll back any dangling transaction first
922 if ( $this->trxLevel
) {
923 if ( $this->trxAtomicLevels
) {
924 // Cannot let incomplete atomic sections be committed
925 $levels = $this->flatAtomicSectionList();
926 $exception = new DBUnexpectedError(
928 __METHOD__
. ": atomic sections $levels are still open."
930 } elseif ( $this->trxAutomatic
) {
931 // Only the connection manager can commit non-empty DBO_TRX transactions
932 // (empty ones we can silently roll back)
933 if ( $this->writesOrCallbacksPending() ) {
934 $exception = new DBUnexpectedError(
937 ": mass commit/rollback of peer transaction required (DBO_TRX set)."
941 // Manual transactions should have been committed or rolled
942 // back, even if empty.
943 $exception = new DBUnexpectedError(
945 __METHOD__
. ": transaction is still open (from {$this->trxFname})."
949 if ( $this->trxEndCallbacksSuppressed
) {
950 $exception = $exception ?
: new DBUnexpectedError(
952 __METHOD__
. ': callbacks are suppressed; cannot properly commit.'
956 // Rollback the changes and run any callbacks as needed
957 $this->rollback( __METHOD__
, self
::FLUSHING_INTERNAL
);
960 // Close the actual connection in the binding handle
961 $closed = $this->closeConnection();
964 $closed = true; // already closed; nothing to do
967 $this->opened
= false;
969 // Throw any unexpected errors after having disconnected
970 if ( $exception instanceof Exception
) {
974 // Sanity check that no callbacks are dangling
975 $fnames = $this->pendingWriteAndCallbackCallers();
977 throw new RuntimeException(
978 "Transaction callbacks are still pending:\n" . implode( ', ', $fnames )
986 * Make sure isOpen() returns true as a sanity check
988 * @throws DBUnexpectedError
990 protected function assertOpen() {
991 if ( !$this->isOpen() ) {
992 throw new DBUnexpectedError( $this, "DB connection was already closed." );
997 * Closes underlying database connection
999 * @return bool Whether connection was closed successfully
1001 abstract protected function closeConnection();
1004 * @deprecated since 1.32
1005 * @param string $error Fallback message, if none is given by DB
1006 * @throws DBConnectionError
1008 public function reportConnectionError( $error = 'Unknown error' ) {
1009 call_user_func( $this->deprecationLogger
, 'Use of ' . __METHOD__
. ' is deprecated.' );
1010 throw new DBConnectionError( $this, $this->lastError() ?
: $error );
1014 * Run a query and return a DBMS-dependent wrapper (that has all IResultWrapper methods)
1016 * This might return things, such as mysqli_result, that do not formally implement
1017 * IResultWrapper, but nonetheless implement all of its methods correctly
1019 * @param string $sql SQL query.
1020 * @return IResultWrapper|bool Iterator to feed to fetchObject/fetchRow; false on failure
1022 abstract protected function doQuery( $sql );
1025 * Determine whether a query writes to the DB. When in doubt, this returns true.
1029 * - Subsequent web requests should not need to wait for replication from
1030 * the master position seen by this web request, unless this request made
1031 * changes to the master. This is handled by ChronologyProtector by checking
1032 * doneWrites() at the end of the request. doneWrites() returns true if any
1033 * query set lastWriteTime; which query() does based on isWriteQuery().
1035 * - Reject write queries to replica DBs, in query().
1037 * @param string $sql
1040 protected function isWriteQuery( $sql ) {
1041 // BEGIN and COMMIT queries are considered read queries here.
1042 // Database backends and drivers (MySQL, MariaDB, php-mysqli) generally
1043 // treat these as write queries, in that their results have "affected rows"
1044 // as meta data as from writes, instead of "num rows" as from reads.
1045 // But, we treat them as read queries because when reading data (from
1046 // either replica or master) we use transactions to enable repeatable-read
1047 // snapshots, which ensures we get consistent results from the same snapshot
1048 // for all queries within a request. Use cases:
1049 // - Treating these as writes would trigger ChronologyProtector (see method doc).
1050 // - We use this method to reject writes to replicas, but we need to allow
1051 // use of transactions on replicas for read snapshots. This fine given
1052 // that transactions by themselves don't make changes, only actual writes
1053 // within the transaction matter, which we still detect.
1055 '/^(?:SELECT|BEGIN|ROLLBACK|COMMIT|SET|SHOW|EXPLAIN|\(SELECT)\b/i', $sql );
1059 * @param string $sql
1060 * @return string|null
1062 protected function getQueryVerb( $sql ) {
1063 return preg_match( '/^\s*([a-z]+)/i', $sql, $m ) ?
strtoupper( $m[1] ) : null;
1067 * Determine whether a SQL statement is sensitive to isolation level.
1069 * A SQL statement is considered transactable if its result could vary
1070 * depending on the transaction isolation level. Operational commands
1071 * such as 'SET' and 'SHOW' are not considered to be transactable.
1073 * Main purpose: Used by query() to decide whether to begin a transaction
1074 * before the current query (in DBO_TRX mode, on by default).
1076 * @param string $sql
1079 protected function isTransactableQuery( $sql ) {
1081 $this->getQueryVerb( $sql ),
1082 [ 'BEGIN', 'ROLLBACK', 'COMMIT', 'SET', 'SHOW', 'CREATE', 'ALTER' ],
1088 * @param string $sql A SQL query
1089 * @return bool Whether $sql is SQL for TEMPORARY table operation
1091 protected function registerTempTableOperation( $sql ) {
1093 '/^CREATE\s+TEMPORARY\s+TABLE\s+(?:IF\s+NOT\s+EXISTS\s+)?[`"\']?(\w+)[`"\']?/i',
1097 $this->sessionTempTables
[$matches[1]] = 1;
1100 } elseif ( preg_match(
1101 '/^DROP\s+(?:TEMPORARY\s+)?TABLE\s+(?:IF\s+EXISTS\s+)?[`"\']?(\w+)[`"\']?/i',
1105 $isTemp = isset( $this->sessionTempTables
[$matches[1]] );
1106 unset( $this->sessionTempTables
[$matches[1]] );
1109 } elseif ( preg_match(
1110 '/^TRUNCATE\s+(?:TEMPORARY\s+)?TABLE\s+(?:IF\s+EXISTS\s+)?[`"\']?(\w+)[`"\']?/i',
1114 return isset( $this->sessionTempTables
[$matches[1]] );
1115 } elseif ( preg_match(
1116 '/^(?:INSERT\s+(?:\w+\s+)?INTO|UPDATE|DELETE\s+FROM)\s+[`"\']?(\w+)[`"\']?/i',
1120 return isset( $this->sessionTempTables
[$matches[1]] );
1126 public function query( $sql, $fname = __METHOD__
, $tempIgnore = false ) {
1127 $this->assertTransactionStatus( $sql, $fname );
1129 # Avoid fatals if close() was called
1130 $this->assertOpen();
1132 $priorWritesPending = $this->writesOrCallbacksPending();
1133 $this->lastQuery
= $sql;
1135 $isWrite = $this->isWriteQuery( $sql );
1137 $isNonTempWrite = !$this->registerTempTableOperation( $sql );
1139 $isNonTempWrite = false;
1143 if ( $this->getLBInfo( 'replica' ) === true ) {
1146 'Write operations are not allowed on replica database connections.'
1149 # In theory, non-persistent writes are allowed in read-only mode, but due to things
1150 # like https://bugs.mysql.com/bug.php?id=33669 that might not work anyway...
1151 $reason = $this->getReadOnlyReason();
1152 if ( $reason !== false ) {
1153 throw new DBReadOnlyError( $this, "Database is read-only: $reason" );
1155 # Set a flag indicating that writes have been done
1156 $this->lastWriteTime
= microtime( true );
1159 # Add trace comment to the begin of the sql string, right after the operator.
1160 # Or, for one-word queries (like "BEGIN" or COMMIT") add it to the end (T44598)
1161 $commentedSql = preg_replace( '/\s|$/', " /* $fname {$this->agent} */ ", $sql, 1 );
1163 # Start implicit transactions that wrap the request if DBO_TRX is enabled
1164 if ( !$this->trxLevel
&& $this->getFlag( self
::DBO_TRX
)
1165 && $this->isTransactableQuery( $sql )
1167 $this->begin( __METHOD__
. " ($fname)", self
::TRANSACTION_INTERNAL
);
1168 $this->trxAutomatic
= true;
1171 # Keep track of whether the transaction has write queries pending
1172 if ( $this->trxLevel
&& !$this->trxDoneWrites
&& $isWrite ) {
1173 $this->trxDoneWrites
= true;
1174 $this->trxProfiler
->transactionWritingIn(
1175 $this->server
, $this->getDomainID(), $this->trxShortId
);
1178 if ( $this->getFlag( self
::DBO_DEBUG
) ) {
1179 $this->queryLogger
->debug( "{$this->getDomainID()} {$commentedSql}" );
1182 # Send the query to the server and fetch any corresponding errors
1183 $ret = $this->doProfiledQuery( $sql, $commentedSql, $isNonTempWrite, $fname );
1184 $lastError = $this->lastError();
1185 $lastErrno = $this->lastErrno();
1187 # Try reconnecting if the connection was lost
1188 if ( $ret === false && $this->wasConnectionLoss() ) {
1189 # Check if any meaningful session state was lost
1190 $recoverable = $this->canRecoverFromDisconnect( $sql, $priorWritesPending );
1191 # Update session state tracking and try to restore the connection
1192 $reconnected = $this->replaceLostConnection( __METHOD__
);
1193 # Silently resend the query to the server if it is safe and possible
1194 if ( $reconnected && $recoverable ) {
1195 $ret = $this->doProfiledQuery( $sql, $commentedSql, $isNonTempWrite, $fname );
1196 $lastError = $this->lastError();
1197 $lastErrno = $this->lastErrno();
1199 if ( $ret === false && $this->wasConnectionLoss() ) {
1200 # Query probably causes disconnects; reconnect and do not re-run it
1201 $this->replaceLostConnection( __METHOD__
);
1206 if ( $ret === false ) {
1207 if ( $this->trxLevel
) {
1208 if ( $this->wasKnownStatementRollbackError() ) {
1209 # We're ignoring an error that caused just the current query to be aborted.
1210 # But log the cause so we can log a deprecation notice if a caller actually
1212 $this->trxStatusIgnoredCause
= [ $lastError, $lastErrno, $fname ];
1214 # Either the query was aborted or all queries after BEGIN where aborted.
1215 # In the first case, the only options going forward are (a) ROLLBACK, or
1216 # (b) ROLLBACK TO SAVEPOINT (if one was set). If the later case, the only
1217 # option is ROLLBACK, since the snapshots would have been released.
1218 $this->trxStatus
= self
::STATUS_TRX_ERROR
;
1219 $this->trxStatusCause
=
1220 $this->makeQueryException( $lastError, $lastErrno, $sql, $fname );
1221 $tempIgnore = false; // cannot recover
1222 $this->trxStatusIgnoredCause
= null;
1226 $this->reportQueryError( $lastError, $lastErrno, $sql, $fname, $tempIgnore );
1229 return $this->resultObject( $ret );
1233 * Wrapper for query() that also handles profiling, logging, and affected row count updates
1235 * @param string $sql Original SQL query
1236 * @param string $commentedSql SQL query with debugging/trace comment
1237 * @param bool $isWrite Whether the query is a (non-temporary) write operation
1238 * @param string $fname Name of the calling function
1239 * @return bool|ResultWrapper True for a successful write query, ResultWrapper
1240 * object for a successful read query, or false on failure
1242 private function doProfiledQuery( $sql, $commentedSql, $isWrite, $fname ) {
1243 $isMaster = !is_null( $this->getLBInfo( 'master' ) );
1244 # generalizeSQL() will probably cut down the query to reasonable
1245 # logging size most of the time. The substr is really just a sanity check.
1247 $queryProf = 'query-m: ' . substr( self
::generalizeSQL( $sql ), 0, 255 );
1249 $queryProf = 'query: ' . substr( self
::generalizeSQL( $sql ), 0, 255 );
1252 # Include query transaction state
1253 $queryProf .= $this->trxShortId ?
" [TRX#{$this->trxShortId}]" : "";
1255 $startTime = microtime( true );
1256 if ( $this->profiler
) {
1257 $this->profiler
->profileIn( $queryProf );
1259 $this->affectedRowCount
= null;
1260 $ret = $this->doQuery( $commentedSql );
1261 $this->affectedRowCount
= $this->affectedRows();
1262 if ( $this->profiler
) {
1263 $this->profiler
->profileOut( $queryProf );
1265 $queryRuntime = max( microtime( true ) - $startTime, 0.0 );
1267 unset( $queryProfSection ); // profile out (if set)
1269 if ( $ret !== false ) {
1270 $this->lastPing
= $startTime;
1271 if ( $isWrite && $this->trxLevel
) {
1272 $this->updateTrxWriteQueryTime( $sql, $queryRuntime, $this->affectedRows() );
1273 $this->trxWriteCallers
[] = $fname;
1277 if ( $sql === self
::PING_QUERY
) {
1278 $this->rttEstimate
= $queryRuntime;
1281 $this->trxProfiler
->recordQueryCompletion(
1285 $isWrite ?
$this->affectedRows() : $this->numRows( $ret )
1287 $this->queryLogger
->debug( $sql, [
1289 'master' => $isMaster,
1290 'runtime' => $queryRuntime,
1297 * Update the estimated run-time of a query, not counting large row lock times
1299 * LoadBalancer can be set to rollback transactions that will create huge replication
1300 * lag. It bases this estimate off of pendingWriteQueryDuration(). Certain simple
1301 * queries, like inserting a row can take a long time due to row locking. This method
1302 * uses some simple heuristics to discount those cases.
1304 * @param string $sql A SQL write query
1305 * @param float $runtime Total runtime, including RTT
1306 * @param int $affected Affected row count
1308 private function updateTrxWriteQueryTime( $sql, $runtime, $affected ) {
1309 // Whether this is indicative of replica DB runtime (except for RBR or ws_repl)
1310 $indicativeOfReplicaRuntime = true;
1311 if ( $runtime > self
::SLOW_WRITE_SEC
) {
1312 $verb = $this->getQueryVerb( $sql );
1313 // insert(), upsert(), replace() are fast unless bulky in size or blocked on locks
1314 if ( $verb === 'INSERT' ) {
1315 $indicativeOfReplicaRuntime = $this->affectedRows() > self
::SMALL_WRITE_ROWS
;
1316 } elseif ( $verb === 'REPLACE' ) {
1317 $indicativeOfReplicaRuntime = $this->affectedRows() > self
::SMALL_WRITE_ROWS
/ 2;
1321 $this->trxWriteDuration +
= $runtime;
1322 $this->trxWriteQueryCount +
= 1;
1323 $this->trxWriteAffectedRows +
= $affected;
1324 if ( $indicativeOfReplicaRuntime ) {
1325 $this->trxWriteAdjDuration +
= $runtime;
1326 $this->trxWriteAdjQueryCount +
= 1;
1331 * @param string $sql
1332 * @param string $fname
1333 * @throws DBTransactionStateError
1335 private function assertTransactionStatus( $sql, $fname ) {
1336 if ( $this->getQueryVerb( $sql ) === 'ROLLBACK' ) { // transaction/savepoint
1340 if ( $this->trxStatus
< self
::STATUS_TRX_OK
) {
1341 throw new DBTransactionStateError(
1343 "Cannot execute query from $fname while transaction status is ERROR.",
1345 $this->trxStatusCause
1347 } elseif ( $this->trxStatus
=== self
::STATUS_TRX_OK
&& $this->trxStatusIgnoredCause
) {
1348 list( $iLastError, $iLastErrno, $iFname ) = $this->trxStatusIgnoredCause
;
1349 call_user_func( $this->deprecationLogger
,
1350 "Caller from $fname ignored an error originally raised from $iFname: " .
1351 "[$iLastErrno] $iLastError"
1353 $this->trxStatusIgnoredCause
= null;
1357 public function assertNoOpenTransactions() {
1358 if ( $this->explicitTrxActive() ) {
1359 throw new DBTransactionError(
1361 "Explicit transaction still active. A caller may have caught an error. "
1362 . "Open transactions: " . $this->flatAtomicSectionList()
1368 * Determine whether or not it is safe to retry queries after a database
1369 * connection is lost
1371 * @param string $sql SQL query
1372 * @param bool $priorWritesPending Whether there is a transaction open with
1373 * possible write queries or transaction pre-commit/idle callbacks
1374 * waiting on it to finish.
1375 * @return bool True if it is safe to retry the query, false otherwise
1377 private function canRecoverFromDisconnect( $sql, $priorWritesPending ) {
1378 # Transaction dropped; this can mean lost writes, or REPEATABLE-READ snapshots.
1379 # Dropped connections also mean that named locks are automatically released.
1380 # Only allow error suppression in autocommit mode or when the lost transaction
1381 # didn't matter anyway (aside from DBO_TRX snapshot loss).
1382 if ( $this->namedLocksHeld
) {
1383 return false; // possible critical section violation
1384 } elseif ( $this->sessionTempTables
) {
1385 return false; // tables might be queried latter
1386 } elseif ( $sql === 'COMMIT' ) {
1387 return !$priorWritesPending; // nothing written anyway? (T127428)
1388 } elseif ( $sql === 'ROLLBACK' ) {
1389 return true; // transaction lost...which is also what was requested :)
1390 } elseif ( $this->explicitTrxActive() ) {
1391 return false; // don't drop atomocity and explicit snapshots
1392 } elseif ( $priorWritesPending ) {
1393 return false; // prior writes lost from implicit transaction
1400 * Clean things up after session (and thus transaction) loss
1402 private function handleSessionLoss() {
1403 // Clean up tracking of session-level things...
1404 // https://dev.mysql.com/doc/refman/5.7/en/implicit-commit.html
1405 // https://www.postgresql.org/docs/9.2/static/sql-createtable.html (ignoring ON COMMIT)
1406 $this->sessionTempTables
= [];
1407 // https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_get-lock
1408 // https://www.postgresql.org/docs/9.4/static/functions-admin.html#FUNCTIONS-ADVISORY-LOCKS
1409 $this->namedLocksHeld
= [];
1410 // Session loss implies transaction loss
1411 $this->handleTransactionLoss();
1415 * Clean things up after transaction loss
1417 private function handleTransactionLoss() {
1418 $this->trxLevel
= 0;
1419 $this->trxAtomicCounter
= 0;
1420 $this->trxIdleCallbacks
= []; // T67263; transaction already lost
1421 $this->trxPreCommitCallbacks
= []; // T67263; transaction already lost
1423 // Handle callbacks in trxEndCallbacks, e.g. onTransactionResolution().
1424 // If callback suppression is set then the array will remain unhandled.
1425 $this->runOnTransactionIdleCallbacks( self
::TRIGGER_ROLLBACK
);
1426 } catch ( Exception
$ex ) {
1427 // Already logged; move on...
1430 // Handle callbacks in trxRecurringCallbacks, e.g. setTransactionListener()
1431 $this->runTransactionListenerCallbacks( self
::TRIGGER_ROLLBACK
);
1432 } catch ( Exception
$ex ) {
1433 // Already logged; move on...
1438 * Checks whether the cause of the error is detected to be a timeout.
1440 * It returns false by default, and not all engines support detecting this yet.
1441 * If this returns false, it will be treated as a generic query error.
1443 * @param string $error Error text
1444 * @param int $errno Error number
1447 protected function wasQueryTimeout( $error, $errno ) {
1452 * Report a query error. Log the error, and if neither the object ignore
1453 * flag nor the $tempIgnore flag is set, throw a DBQueryError.
1455 * @param string $error
1457 * @param string $sql
1458 * @param string $fname
1459 * @param bool $tempIgnore
1460 * @throws DBQueryError
1462 public function reportQueryError( $error, $errno, $sql, $fname, $tempIgnore = false ) {
1463 if ( $tempIgnore ) {
1464 $this->queryLogger
->debug( "SQL ERROR (ignored): $error\n" );
1466 $exception = $this->makeQueryException( $error, $errno, $sql, $fname );
1473 * @param string $error
1474 * @param string|int $errno
1475 * @param string $sql
1476 * @param string $fname
1479 private function makeQueryException( $error, $errno, $sql, $fname ) {
1480 $sql1line = mb_substr( str_replace( "\n", "\\n", $sql ), 0, 5 * 1024 );
1481 $this->queryLogger
->error(
1482 "{fname}\t{db_server}\t{errno}\t{error}\t{sql1line}",
1483 $this->getLogContext( [
1484 'method' => __METHOD__
,
1487 'sql1line' => $sql1line,
1491 $this->queryLogger
->debug( "SQL ERROR: " . $error . "\n" );
1492 $wasQueryTimeout = $this->wasQueryTimeout( $error, $errno );
1493 if ( $wasQueryTimeout ) {
1494 $e = new DBQueryTimeoutError( $this, $error, $errno, $sql, $fname );
1496 $e = new DBQueryError( $this, $error, $errno, $sql, $fname );
1502 public function freeResult( $res ) {
1505 public function selectField(
1506 $table, $var, $cond = '', $fname = __METHOD__
, $options = [], $join_conds = []
1508 if ( $var === '*' ) { // sanity
1509 throw new DBUnexpectedError( $this, "Cannot use a * field: got '$var'" );
1512 if ( !is_array( $options ) ) {
1513 $options = [ $options ];
1516 $options['LIMIT'] = 1;
1518 $res = $this->select( $table, $var, $cond, $fname, $options, $join_conds );
1519 if ( $res === false ||
!$this->numRows( $res ) ) {
1523 $row = $this->fetchRow( $res );
1525 if ( $row !== false ) {
1526 return reset( $row );
1532 public function selectFieldValues(
1533 $table, $var, $cond = '', $fname = __METHOD__
, $options = [], $join_conds = []
1535 if ( $var === '*' ) { // sanity
1536 throw new DBUnexpectedError( $this, "Cannot use a * field" );
1537 } elseif ( !is_string( $var ) ) { // sanity
1538 throw new DBUnexpectedError( $this, "Cannot use an array of fields" );
1541 if ( !is_array( $options ) ) {
1542 $options = [ $options ];
1545 $res = $this->select( $table, $var, $cond, $fname, $options, $join_conds );
1546 if ( $res === false ) {
1551 foreach ( $res as $row ) {
1552 $values[] = $row->$var;
1559 * Returns an optional USE INDEX clause to go after the table, and a
1560 * string to go at the end of the query.
1562 * @param array $options Associative array of options to be turned into
1563 * an SQL query, valid keys are listed in the function.
1565 * @see Database::select()
1567 protected function makeSelectOptions( $options ) {
1568 $preLimitTail = $postLimitTail = '';
1573 foreach ( $options as $key => $option ) {
1574 if ( is_numeric( $key ) ) {
1575 $noKeyOptions[$option] = true;
1579 $preLimitTail .= $this->makeGroupByWithHaving( $options );
1581 $preLimitTail .= $this->makeOrderBy( $options );
1583 if ( isset( $noKeyOptions['FOR UPDATE'] ) ) {
1584 $postLimitTail .= ' FOR UPDATE';
1587 if ( isset( $noKeyOptions['LOCK IN SHARE MODE'] ) ) {
1588 $postLimitTail .= ' LOCK IN SHARE MODE';
1591 if ( isset( $noKeyOptions['DISTINCT'] ) ||
isset( $noKeyOptions['DISTINCTROW'] ) ) {
1592 $startOpts .= 'DISTINCT';
1595 # Various MySQL extensions
1596 if ( isset( $noKeyOptions['STRAIGHT_JOIN'] ) ) {
1597 $startOpts .= ' /*! STRAIGHT_JOIN */';
1600 if ( isset( $noKeyOptions['HIGH_PRIORITY'] ) ) {
1601 $startOpts .= ' HIGH_PRIORITY';
1604 if ( isset( $noKeyOptions['SQL_BIG_RESULT'] ) ) {
1605 $startOpts .= ' SQL_BIG_RESULT';
1608 if ( isset( $noKeyOptions['SQL_BUFFER_RESULT'] ) ) {
1609 $startOpts .= ' SQL_BUFFER_RESULT';
1612 if ( isset( $noKeyOptions['SQL_SMALL_RESULT'] ) ) {
1613 $startOpts .= ' SQL_SMALL_RESULT';
1616 if ( isset( $noKeyOptions['SQL_CALC_FOUND_ROWS'] ) ) {
1617 $startOpts .= ' SQL_CALC_FOUND_ROWS';
1620 if ( isset( $noKeyOptions['SQL_CACHE'] ) ) {
1621 $startOpts .= ' SQL_CACHE';
1624 if ( isset( $noKeyOptions['SQL_NO_CACHE'] ) ) {
1625 $startOpts .= ' SQL_NO_CACHE';
1628 if ( isset( $options['USE INDEX'] ) && is_string( $options['USE INDEX'] ) ) {
1629 $useIndex = $this->useIndexClause( $options['USE INDEX'] );
1633 if ( isset( $options['IGNORE INDEX'] ) && is_string( $options['IGNORE INDEX'] ) ) {
1634 $ignoreIndex = $this->ignoreIndexClause( $options['IGNORE INDEX'] );
1639 return [ $startOpts, $useIndex, $preLimitTail, $postLimitTail, $ignoreIndex ];
1643 * Returns an optional GROUP BY with an optional HAVING
1645 * @param array $options Associative array of options
1647 * @see Database::select()
1650 protected function makeGroupByWithHaving( $options ) {
1652 if ( isset( $options['GROUP BY'] ) ) {
1653 $gb = is_array( $options['GROUP BY'] )
1654 ?
implode( ',', $options['GROUP BY'] )
1655 : $options['GROUP BY'];
1656 $sql .= ' GROUP BY ' . $gb;
1658 if ( isset( $options['HAVING'] ) ) {
1659 $having = is_array( $options['HAVING'] )
1660 ?
$this->makeList( $options['HAVING'], self
::LIST_AND
)
1661 : $options['HAVING'];
1662 $sql .= ' HAVING ' . $having;
1669 * Returns an optional ORDER BY
1671 * @param array $options Associative array of options
1673 * @see Database::select()
1676 protected function makeOrderBy( $options ) {
1677 if ( isset( $options['ORDER BY'] ) ) {
1678 $ob = is_array( $options['ORDER BY'] )
1679 ?
implode( ',', $options['ORDER BY'] )
1680 : $options['ORDER BY'];
1682 return ' ORDER BY ' . $ob;
1688 public function select(
1689 $table, $vars, $conds = '', $fname = __METHOD__
, $options = [], $join_conds = []
1691 $sql = $this->selectSQLText( $table, $vars, $conds, $fname, $options, $join_conds );
1693 return $this->query( $sql, $fname );
1696 public function selectSQLText( $table, $vars, $conds = '', $fname = __METHOD__
,
1697 $options = [], $join_conds = []
1699 if ( is_array( $vars ) ) {
1700 $fields = implode( ',', $this->fieldNamesWithAlias( $vars ) );
1705 $options = (array)$options;
1706 $useIndexes = ( isset( $options['USE INDEX'] ) && is_array( $options['USE INDEX'] ) )
1707 ?
$options['USE INDEX']
1710 isset( $options['IGNORE INDEX'] ) &&
1711 is_array( $options['IGNORE INDEX'] )
1713 ?
$options['IGNORE INDEX']
1717 $this->selectOptionsIncludeLocking( $options ) &&
1718 $this->selectFieldsOrOptionsAggregate( $vars, $options )
1720 // Some DB types (postgres/oracle) disallow FOR UPDATE with aggregate
1721 // functions. Discourage use of such queries to encourage compatibility.
1723 $this->deprecationLogger
,
1724 __METHOD__
. ": aggregation used with a locking SELECT ($fname)."
1728 if ( is_array( $table ) ) {
1730 $this->tableNamesWithIndexClauseOrJOIN(
1731 $table, $useIndexes, $ignoreIndexes, $join_conds );
1732 } elseif ( $table != '' ) {
1734 $this->tableNamesWithIndexClauseOrJOIN(
1735 [ $table ], $useIndexes, $ignoreIndexes, [] );
1740 list( $startOpts, $useIndex, $preLimitTail, $postLimitTail, $ignoreIndex ) =
1741 $this->makeSelectOptions( $options );
1743 if ( is_array( $conds ) ) {
1744 $conds = $this->makeList( $conds, self
::LIST_AND
);
1747 if ( $conds === null ||
$conds === false ) {
1748 $this->queryLogger
->warning(
1752 . ' with incorrect parameters: $conds must be a string or an array'
1757 if ( $conds === '' ||
$conds === '*' ) {
1758 $sql = "SELECT $startOpts $fields $from $useIndex $ignoreIndex $preLimitTail";
1759 } elseif ( is_string( $conds ) ) {
1760 $sql = "SELECT $startOpts $fields $from $useIndex $ignoreIndex " .
1761 "WHERE $conds $preLimitTail";
1763 throw new DBUnexpectedError( $this, __METHOD__
. ' called with incorrect parameters' );
1766 if ( isset( $options['LIMIT'] ) ) {
1767 $sql = $this->limitResult( $sql, $options['LIMIT'],
1768 $options['OFFSET'] ??
false );
1770 $sql = "$sql $postLimitTail";
1772 if ( isset( $options['EXPLAIN'] ) ) {
1773 $sql = 'EXPLAIN ' . $sql;
1779 public function selectRow( $table, $vars, $conds, $fname = __METHOD__
,
1780 $options = [], $join_conds = []
1782 $options = (array)$options;
1783 $options['LIMIT'] = 1;
1784 $res = $this->select( $table, $vars, $conds, $fname, $options, $join_conds );
1786 if ( $res === false ) {
1790 if ( !$this->numRows( $res ) ) {
1794 $obj = $this->fetchObject( $res );
1799 public function estimateRowCount(
1800 $table, $var = '*', $conds = '', $fname = __METHOD__
, $options = [], $join_conds = []
1802 $conds = $this->normalizeConditions( $conds, $fname );
1803 $column = $this->extractSingleFieldFromList( $var );
1804 if ( is_string( $column ) && !in_array( $column, [ '*', '1' ] ) ) {
1805 $conds[] = "$column IS NOT NULL";
1808 $res = $this->select(
1809 $table, [ 'rowcount' => 'COUNT(*)' ], $conds, $fname, $options, $join_conds
1811 $row = $res ?
$this->fetchRow( $res ) : [];
1813 return isset( $row['rowcount'] ) ?
(int)$row['rowcount'] : 0;
1816 public function selectRowCount(
1817 $tables, $var = '*', $conds = '', $fname = __METHOD__
, $options = [], $join_conds = []
1819 $conds = $this->normalizeConditions( $conds, $fname );
1820 $column = $this->extractSingleFieldFromList( $var );
1821 if ( is_string( $column ) && !in_array( $column, [ '*', '1' ] ) ) {
1822 $conds[] = "$column IS NOT NULL";
1825 $res = $this->select(
1827 'tmp_count' => $this->buildSelectSubquery(
1836 [ 'rowcount' => 'COUNT(*)' ],
1840 $row = $res ?
$this->fetchRow( $res ) : [];
1842 return isset( $row['rowcount'] ) ?
(int)$row['rowcount'] : 0;
1846 * @param string|array $options
1849 private function selectOptionsIncludeLocking( $options ) {
1850 $options = (array)$options;
1851 foreach ( [ 'FOR UPDATE', 'LOCK IN SHARE MODE' ] as $lock ) {
1852 if ( in_array( $lock, $options, true ) ) {
1861 * @param array|string $fields
1862 * @param array|string $options
1865 private function selectFieldsOrOptionsAggregate( $fields, $options ) {
1866 foreach ( (array)$options as $key => $value ) {
1867 if ( is_string( $key ) ) {
1868 if ( preg_match( '/^(?:GROUP BY|HAVING)$/i', $key ) ) {
1871 } elseif ( is_string( $value ) ) {
1872 if ( preg_match( '/^(?:DISTINCT|DISTINCTROW)$/i', $value ) ) {
1878 $regex = '/^(?:COUNT|MIN|MAX|SUM|GROUP_CONCAT|LISTAGG|ARRAY_AGG)\s*\\(/i';
1879 foreach ( (array)$fields as $field ) {
1880 if ( is_string( $field ) && preg_match( $regex, $field ) ) {
1889 * @param array|string $conds
1890 * @param string $fname
1893 final protected function normalizeConditions( $conds, $fname ) {
1894 if ( $conds === null ||
$conds === false ) {
1895 $this->queryLogger
->warning(
1899 . ' with incorrect parameters: $conds must be a string or an array'
1904 if ( !is_array( $conds ) ) {
1905 $conds = ( $conds === '' ) ?
[] : [ $conds ];
1912 * @param array|string $var Field parameter in the style of select()
1913 * @return string|null Column name or null; ignores aliases
1914 * @throws DBUnexpectedError Errors out if multiple columns are given
1916 final protected function extractSingleFieldFromList( $var ) {
1917 if ( is_array( $var ) ) {
1920 } elseif ( count( $var ) == 1 ) {
1921 $column = $var[0] ??
reset( $var );
1923 throw new DBUnexpectedError( $this, __METHOD__
. ': got multiple columns.' );
1932 public function lockForUpdate(
1933 $table, $conds = '', $fname = __METHOD__
, $options = [], $join_conds = []
1935 if ( !$this->trxLevel
&& !$this->getFlag( self
::DBO_TRX
) ) {
1936 throw new DBUnexpectedError(
1938 __METHOD__
. ': no transaction is active nor is DBO_TRX set'
1942 $options = (array)$options;
1943 $options[] = 'FOR UPDATE';
1945 return $this->selectRowCount( $table, '*', $conds, $fname, $options, $join_conds );
1949 * Removes most variables from an SQL query and replaces them with X or N for numbers.
1950 * It's only slightly flawed. Don't use for anything important.
1952 * @param string $sql A SQL Query
1956 protected static function generalizeSQL( $sql ) {
1957 # This does the same as the regexp below would do, but in such a way
1958 # as to avoid crashing php on some large strings.
1959 # $sql = preg_replace( "/'([^\\\\']|\\\\.)*'|\"([^\\\\\"]|\\\\.)*\"/", "'X'", $sql );
1961 $sql = str_replace( "\\\\", '', $sql );
1962 $sql = str_replace( "\\'", '', $sql );
1963 $sql = str_replace( "\\\"", '', $sql );
1964 $sql = preg_replace( "/'.*'/s", "'X'", $sql );
1965 $sql = preg_replace( '/".*"/s', "'X'", $sql );
1967 # All newlines, tabs, etc replaced by single space
1968 $sql = preg_replace( '/\s+/', ' ', $sql );
1971 # except the ones surrounded by characters, e.g. l10n
1972 $sql = preg_replace( '/-?\d+(,-?\d+)+/s', 'N,...,N', $sql );
1973 $sql = preg_replace( '/(?<![a-zA-Z])-?\d+(?![a-zA-Z])/s', 'N', $sql );
1978 public function fieldExists( $table, $field, $fname = __METHOD__
) {
1979 $info = $this->fieldInfo( $table, $field );
1984 public function indexExists( $table, $index, $fname = __METHOD__
) {
1985 if ( !$this->tableExists( $table ) ) {
1989 $info = $this->indexInfo( $table, $index, $fname );
1990 if ( is_null( $info ) ) {
1993 return $info !== false;
1997 abstract public function tableExists( $table, $fname = __METHOD__
);
1999 public function indexUnique( $table, $index ) {
2000 $indexInfo = $this->indexInfo( $table, $index );
2002 if ( !$indexInfo ) {
2006 return !$indexInfo[0]->Non_unique
;
2010 * Helper for Database::insert().
2012 * @param array $options
2015 protected function makeInsertOptions( $options ) {
2016 return implode( ' ', $options );
2019 public function insert( $table, $a, $fname = __METHOD__
, $options = [] ) {
2020 # No rows to insert, easy just return now
2021 if ( !count( $a ) ) {
2025 $table = $this->tableName( $table );
2027 if ( !is_array( $options ) ) {
2028 $options = [ $options ];
2032 if ( isset( $options['fileHandle'] ) ) {
2033 $fh = $options['fileHandle'];
2035 $options = $this->makeInsertOptions( $options );
2037 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
2039 $keys = array_keys( $a[0] );
2042 $keys = array_keys( $a );
2045 $sql = 'INSERT ' . $options .
2046 " INTO $table (" . implode( ',', $keys ) . ') VALUES ';
2050 foreach ( $a as $row ) {
2056 $sql .= '(' . $this->makeList( $row ) . ')';
2059 $sql .= '(' . $this->makeList( $a ) . ')';
2062 if ( $fh !== null && false === fwrite( $fh, $sql ) ) {
2064 } elseif ( $fh !== null ) {
2068 return (bool)$this->query( $sql, $fname );
2072 * Make UPDATE options array for Database::makeUpdateOptions
2074 * @param array $options
2077 protected function makeUpdateOptionsArray( $options ) {
2078 if ( !is_array( $options ) ) {
2079 $options = [ $options ];
2084 if ( in_array( 'IGNORE', $options ) ) {
2092 * Make UPDATE options for the Database::update function
2094 * @param array $options The options passed to Database::update
2097 protected function makeUpdateOptions( $options ) {
2098 $opts = $this->makeUpdateOptionsArray( $options );
2100 return implode( ' ', $opts );
2103 public function update( $table, $values, $conds, $fname = __METHOD__
, $options = [] ) {
2104 $table = $this->tableName( $table );
2105 $opts = $this->makeUpdateOptions( $options );
2106 $sql = "UPDATE $opts $table SET " . $this->makeList( $values, self
::LIST_SET
);
2108 if ( $conds !== [] && $conds !== '*' ) {
2109 $sql .= " WHERE " . $this->makeList( $conds, self
::LIST_AND
);
2112 return (bool)$this->query( $sql, $fname );
2115 public function makeList( $a, $mode = self
::LIST_COMMA
) {
2116 if ( !is_array( $a ) ) {
2117 throw new DBUnexpectedError( $this, __METHOD__
. ' called with incorrect parameters' );
2123 foreach ( $a as $field => $value ) {
2125 if ( $mode == self
::LIST_AND
) {
2127 } elseif ( $mode == self
::LIST_OR
) {
2136 if ( ( $mode == self
::LIST_AND ||
$mode == self
::LIST_OR
) && is_numeric( $field ) ) {
2137 $list .= "($value)";
2138 } elseif ( $mode == self
::LIST_SET
&& is_numeric( $field ) ) {
2141 ( $mode == self
::LIST_AND ||
$mode == self
::LIST_OR
) && is_array( $value )
2143 // Remove null from array to be handled separately if found
2144 $includeNull = false;
2145 foreach ( array_keys( $value, null, true ) as $nullKey ) {
2146 $includeNull = true;
2147 unset( $value[$nullKey] );
2149 if ( count( $value ) == 0 && !$includeNull ) {
2150 throw new InvalidArgumentException(
2151 __METHOD__
. ": empty input for field $field" );
2152 } elseif ( count( $value ) == 0 ) {
2153 // only check if $field is null
2154 $list .= "$field IS NULL";
2156 // IN clause contains at least one valid element
2157 if ( $includeNull ) {
2158 // Group subconditions to ensure correct precedence
2161 if ( count( $value ) == 1 ) {
2162 // Special-case single values, as IN isn't terribly efficient
2163 // Don't necessarily assume the single key is 0; we don't
2164 // enforce linear numeric ordering on other arrays here.
2165 $value = array_values( $value )[0];
2166 $list .= $field . " = " . $this->addQuotes( $value );
2168 $list .= $field . " IN (" . $this->makeList( $value ) . ") ";
2170 // if null present in array, append IS NULL
2171 if ( $includeNull ) {
2172 $list .= " OR $field IS NULL)";
2175 } elseif ( $value === null ) {
2176 if ( $mode == self
::LIST_AND ||
$mode == self
::LIST_OR
) {
2177 $list .= "$field IS ";
2178 } elseif ( $mode == self
::LIST_SET
) {
2179 $list .= "$field = ";
2184 $mode == self
::LIST_AND ||
$mode == self
::LIST_OR ||
$mode == self
::LIST_SET
2186 $list .= "$field = ";
2188 $list .= $mode == self
::LIST_NAMES ?
$value : $this->addQuotes( $value );
2195 public function makeWhereFrom2d( $data, $baseKey, $subKey ) {
2198 foreach ( $data as $base => $sub ) {
2199 if ( count( $sub ) ) {
2200 $conds[] = $this->makeList(
2201 [ $baseKey => $base, $subKey => array_keys( $sub ) ],
2207 return $this->makeList( $conds, self
::LIST_OR
);
2209 // Nothing to search for...
2214 public function aggregateValue( $valuedata, $valuename = 'value' ) {
2218 public function bitNot( $field ) {
2222 public function bitAnd( $fieldLeft, $fieldRight ) {
2223 return "($fieldLeft & $fieldRight)";
2226 public function bitOr( $fieldLeft, $fieldRight ) {
2227 return "($fieldLeft | $fieldRight)";
2230 public function buildConcat( $stringList ) {
2231 return 'CONCAT(' . implode( ',', $stringList ) . ')';
2234 public function buildGroupConcatField(
2235 $delim, $table, $field, $conds = '', $join_conds = []
2237 $fld = "GROUP_CONCAT($field SEPARATOR " . $this->addQuotes( $delim ) . ')';
2239 return '(' . $this->selectSQLText( $table, $fld, $conds, null, [], $join_conds ) . ')';
2242 public function buildSubstring( $input, $startPosition, $length = null ) {
2243 $this->assertBuildSubstringParams( $startPosition, $length );
2244 $functionBody = "$input FROM $startPosition";
2245 if ( $length !== null ) {
2246 $functionBody .= " FOR $length";
2248 return 'SUBSTRING(' . $functionBody . ')';
2252 * Check type and bounds for parameters to self::buildSubstring()
2254 * All supported databases have substring functions that behave the same for
2255 * positive $startPosition and non-negative $length, but behaviors differ when
2256 * given 0 or negative $startPosition or negative $length. The simplest
2257 * solution to that is to just forbid those values.
2259 * @param int $startPosition
2260 * @param int|null $length
2263 protected function assertBuildSubstringParams( $startPosition, $length ) {
2264 if ( !is_int( $startPosition ) ||
$startPosition <= 0 ) {
2265 throw new InvalidArgumentException(
2266 '$startPosition must be a positive integer'
2269 if ( !( is_int( $length ) && $length >= 0 ||
$length === null ) ) {
2270 throw new InvalidArgumentException(
2271 '$length must be null or an integer greater than or equal to 0'
2276 public function buildStringCast( $field ) {
2280 public function buildIntegerCast( $field ) {
2281 return 'CAST( ' . $field . ' AS INTEGER )';
2284 public function buildSelectSubquery(
2285 $table, $vars, $conds = '', $fname = __METHOD__
,
2286 $options = [], $join_conds = []
2288 return new Subquery(
2289 $this->selectSQLText( $table, $vars, $conds, $fname, $options, $join_conds )
2293 public function databasesAreIndependent() {
2297 final public function selectDB( $db ) {
2298 $this->selectDomain( new DatabaseDomain(
2300 $this->currentDomain
->getSchema(),
2301 $this->currentDomain
->getTablePrefix()
2307 final public function selectDomain( $domain ) {
2308 $this->doSelectDomain( DatabaseDomain
::newFromId( $domain ) );
2311 protected function doSelectDomain( DatabaseDomain
$domain ) {
2312 $this->currentDomain
= $domain;
2315 public function getDBname() {
2316 return $this->currentDomain
->getDatabase();
2319 public function getServer() {
2320 return $this->server
;
2323 public function tableName( $name, $format = 'quoted' ) {
2324 if ( $name instanceof Subquery
) {
2325 throw new DBUnexpectedError(
2327 __METHOD__
. ': got Subquery instance when expecting a string.'
2331 # Skip the entire process when we have a string quoted on both ends.
2332 # Note that we check the end so that we will still quote any use of
2333 # use of `database`.table. But won't break things if someone wants
2334 # to query a database table with a dot in the name.
2335 if ( $this->isQuotedIdentifier( $name ) ) {
2339 # Lets test for any bits of text that should never show up in a table
2340 # name. Basically anything like JOIN or ON which are actually part of
2341 # SQL queries, but may end up inside of the table value to combine
2342 # sql. Such as how the API is doing.
2343 # Note that we use a whitespace test rather than a \b test to avoid
2344 # any remote case where a word like on may be inside of a table name
2345 # surrounded by symbols which may be considered word breaks.
2346 if ( preg_match( '/(^|\s)(DISTINCT|JOIN|ON|AS)(\s|$)/i', $name ) !== 0 ) {
2347 $this->queryLogger
->warning(
2348 __METHOD__
. ": use of subqueries is not supported this way.",
2349 [ 'trace' => ( new RuntimeException() )->getTraceAsString() ]
2355 # Split database and table into proper variables.
2356 list( $database, $schema, $prefix, $table ) = $this->qualifiedTableComponents( $name );
2358 # Quote $table and apply the prefix if not quoted.
2359 # $tableName might be empty if this is called from Database::replaceVars()
2360 $tableName = "{$prefix}{$table}";
2361 if ( $format === 'quoted'
2362 && !$this->isQuotedIdentifier( $tableName )
2363 && $tableName !== ''
2365 $tableName = $this->addIdentifierQuotes( $tableName );
2368 # Quote $schema and $database and merge them with the table name if needed
2369 $tableName = $this->prependDatabaseOrSchema( $schema, $tableName, $format );
2370 $tableName = $this->prependDatabaseOrSchema( $database, $tableName, $format );
2376 * Get the table components needed for a query given the currently selected database
2378 * @param string $name Table name in the form of db.schema.table, db.table, or table
2379 * @return array (DB name or "" for default, schema name, table prefix, table name)
2381 protected function qualifiedTableComponents( $name ) {
2382 # We reverse the explode so that database.table and table both output the correct table.
2383 $dbDetails = explode( '.', $name, 3 );
2384 if ( count( $dbDetails ) == 3 ) {
2385 list( $database, $schema, $table ) = $dbDetails;
2386 # We don't want any prefix added in this case
2388 } elseif ( count( $dbDetails ) == 2 ) {
2389 list( $database, $table ) = $dbDetails;
2390 # We don't want any prefix added in this case
2392 # In dbs that support it, $database may actually be the schema
2393 # but that doesn't affect any of the functionality here
2396 list( $table ) = $dbDetails;
2397 if ( isset( $this->tableAliases
[$table] ) ) {
2398 $database = $this->tableAliases
[$table]['dbname'];
2399 $schema = is_string( $this->tableAliases
[$table]['schema'] )
2400 ?
$this->tableAliases
[$table]['schema']
2401 : $this->relationSchemaQualifier();
2402 $prefix = is_string( $this->tableAliases
[$table]['prefix'] )
2403 ?
$this->tableAliases
[$table]['prefix']
2404 : $this->tablePrefix();
2407 $schema = $this->relationSchemaQualifier(); # Default schema
2408 $prefix = $this->tablePrefix(); # Default prefix
2412 return [ $database, $schema, $prefix, $table ];
2416 * @param string|null $namespace Database or schema
2417 * @param string $relation Name of table, view, sequence, etc...
2418 * @param string $format One of (raw, quoted)
2419 * @return string Relation name with quoted and merged $namespace as needed
2421 private function prependDatabaseOrSchema( $namespace, $relation, $format ) {
2422 if ( strlen( $namespace ) ) {
2423 if ( $format === 'quoted' && !$this->isQuotedIdentifier( $namespace ) ) {
2424 $namespace = $this->addIdentifierQuotes( $namespace );
2426 $relation = $namespace . '.' . $relation;
2432 public function tableNames() {
2433 $inArray = func_get_args();
2436 foreach ( $inArray as $name ) {
2437 $retVal[$name] = $this->tableName( $name );
2443 public function tableNamesN() {
2444 $inArray = func_get_args();
2447 foreach ( $inArray as $name ) {
2448 $retVal[] = $this->tableName( $name );
2455 * Get an aliased table name
2457 * This returns strings like "tableName AS newTableName" for aliased tables
2458 * and "(SELECT * from tableA) newTablename" for subqueries (e.g. derived tables)
2460 * @see Database::tableName()
2461 * @param string|Subquery $table Table name or object with a 'sql' field
2462 * @param string|bool $alias Table alias (optional)
2463 * @return string SQL name for aliased table. Will not alias a table to its own name
2465 protected function tableNameWithAlias( $table, $alias = false ) {
2466 if ( is_string( $table ) ) {
2467 $quotedTable = $this->tableName( $table );
2468 } elseif ( $table instanceof Subquery
) {
2469 $quotedTable = (string)$table;
2471 throw new InvalidArgumentException( "Table must be a string or Subquery." );
2474 if ( !strlen( $alias ) ||
$alias === $table ) {
2475 if ( $table instanceof Subquery
) {
2476 throw new InvalidArgumentException( "Subquery table missing alias." );
2479 return $quotedTable;
2481 return $quotedTable . ' ' . $this->addIdentifierQuotes( $alias );
2486 * Gets an array of aliased table names
2488 * @param array $tables [ [alias] => table ]
2489 * @return string[] See tableNameWithAlias()
2491 protected function tableNamesWithAlias( $tables ) {
2493 foreach ( $tables as $alias => $table ) {
2494 if ( is_numeric( $alias ) ) {
2497 $retval[] = $this->tableNameWithAlias( $table, $alias );
2504 * Get an aliased field name
2505 * e.g. fieldName AS newFieldName
2507 * @param string $name Field name
2508 * @param string|bool $alias Alias (optional)
2509 * @return string SQL name for aliased field. Will not alias a field to its own name
2511 protected function fieldNameWithAlias( $name, $alias = false ) {
2512 if ( !$alias ||
(string)$alias === (string)$name ) {
2515 return $name . ' AS ' . $this->addIdentifierQuotes( $alias ); // PostgreSQL needs AS
2520 * Gets an array of aliased field names
2522 * @param array $fields [ [alias] => field ]
2523 * @return string[] See fieldNameWithAlias()
2525 protected function fieldNamesWithAlias( $fields ) {
2527 foreach ( $fields as $alias => $field ) {
2528 if ( is_numeric( $alias ) ) {
2531 $retval[] = $this->fieldNameWithAlias( $field, $alias );
2538 * Get the aliased table name clause for a FROM clause
2539 * which might have a JOIN and/or USE INDEX or IGNORE INDEX clause
2541 * @param array $tables ( [alias] => table )
2542 * @param array $use_index Same as for select()
2543 * @param array $ignore_index Same as for select()
2544 * @param array $join_conds Same as for select()
2547 protected function tableNamesWithIndexClauseOrJOIN(
2548 $tables, $use_index = [], $ignore_index = [], $join_conds = []
2552 $use_index = (array)$use_index;
2553 $ignore_index = (array)$ignore_index;
2554 $join_conds = (array)$join_conds;
2556 foreach ( $tables as $alias => $table ) {
2557 if ( !is_string( $alias ) ) {
2558 // No alias? Set it equal to the table name
2562 if ( is_array( $table ) ) {
2563 // A parenthesized group
2564 if ( count( $table ) > 1 ) {
2565 $joinedTable = '(' .
2566 $this->tableNamesWithIndexClauseOrJOIN(
2567 $table, $use_index, $ignore_index, $join_conds ) . ')';
2570 $innerTable = reset( $table );
2571 $innerAlias = key( $table );
2572 $joinedTable = $this->tableNameWithAlias(
2574 is_string( $innerAlias ) ?
$innerAlias : $innerTable
2578 $joinedTable = $this->tableNameWithAlias( $table, $alias );
2581 // Is there a JOIN clause for this table?
2582 if ( isset( $join_conds[$alias] ) ) {
2583 list( $joinType, $conds ) = $join_conds[$alias];
2584 $tableClause = $joinType;
2585 $tableClause .= ' ' . $joinedTable;
2586 if ( isset( $use_index[$alias] ) ) { // has USE INDEX?
2587 $use = $this->useIndexClause( implode( ',', (array)$use_index[$alias] ) );
2589 $tableClause .= ' ' . $use;
2592 if ( isset( $ignore_index[$alias] ) ) { // has IGNORE INDEX?
2593 $ignore = $this->ignoreIndexClause(
2594 implode( ',', (array)$ignore_index[$alias] ) );
2595 if ( $ignore != '' ) {
2596 $tableClause .= ' ' . $ignore;
2599 $on = $this->makeList( (array)$conds, self
::LIST_AND
);
2601 $tableClause .= ' ON (' . $on . ')';
2604 $retJOIN[] = $tableClause;
2605 } elseif ( isset( $use_index[$alias] ) ) {
2606 // Is there an INDEX clause for this table?
2607 $tableClause = $joinedTable;
2608 $tableClause .= ' ' . $this->useIndexClause(
2609 implode( ',', (array)$use_index[$alias] )
2612 $ret[] = $tableClause;
2613 } elseif ( isset( $ignore_index[$alias] ) ) {
2614 // Is there an INDEX clause for this table?
2615 $tableClause = $joinedTable;
2616 $tableClause .= ' ' . $this->ignoreIndexClause(
2617 implode( ',', (array)$ignore_index[$alias] )
2620 $ret[] = $tableClause;
2622 $tableClause = $joinedTable;
2624 $ret[] = $tableClause;
2628 // We can't separate explicit JOIN clauses with ',', use ' ' for those
2629 $implicitJoins = $ret ?
implode( ',', $ret ) : "";
2630 $explicitJoins = $retJOIN ?
implode( ' ', $retJOIN ) : "";
2632 // Compile our final table clause
2633 return implode( ' ', [ $implicitJoins, $explicitJoins ] );
2637 * Allows for index remapping in queries where this is not consistent across DBMS
2639 * @param string $index
2642 protected function indexName( $index ) {
2643 return $this->indexAliases
[$index] ??
$index;
2646 public function addQuotes( $s ) {
2647 if ( $s instanceof Blob
) {
2650 if ( $s === null ) {
2652 } elseif ( is_bool( $s ) ) {
2655 # This will also quote numeric values. This should be harmless,
2656 # and protects against weird problems that occur when they really
2657 # _are_ strings such as article titles and string->number->string
2658 # conversion is not 1:1.
2659 return "'" . $this->strencode( $s ) . "'";
2664 * Quotes an identifier using `backticks` or "double quotes" depending on the database type.
2665 * MySQL uses `backticks` while basically everything else uses double quotes.
2666 * Since MySQL is the odd one out here the double quotes are our generic
2667 * and we implement backticks in DatabaseMysqlBase.
2672 public function addIdentifierQuotes( $s ) {
2673 return '"' . str_replace( '"', '""', $s ) . '"';
2677 * Returns if the given identifier looks quoted or not according to
2678 * the database convention for quoting identifiers .
2680 * @note Do not use this to determine if untrusted input is safe.
2681 * A malicious user can trick this function.
2682 * @param string $name
2685 public function isQuotedIdentifier( $name ) {
2686 return $name[0] == '"' && substr( $name, -1, 1 ) == '"';
2691 * @param string $escapeChar
2694 protected function escapeLikeInternal( $s, $escapeChar = '`' ) {
2695 return str_replace( [ $escapeChar, '%', '_' ],
2696 [ "{$escapeChar}{$escapeChar}", "{$escapeChar}%", "{$escapeChar}_" ],
2700 public function buildLike() {
2701 $params = func_get_args();
2703 if ( count( $params ) > 0 && is_array( $params[0] ) ) {
2704 $params = $params[0];
2709 // We use ` instead of \ as the default LIKE escape character, since addQuotes()
2710 // may escape backslashes, creating problems of double escaping. The `
2711 // character has good cross-DBMS compatibility, avoiding special operators
2712 // in MS SQL like ^ and %
2715 foreach ( $params as $value ) {
2716 if ( $value instanceof LikeMatch
) {
2717 $s .= $value->toString();
2719 $s .= $this->escapeLikeInternal( $value, $escapeChar );
2724 $this->addQuotes( $s ) . ' ESCAPE ' . $this->addQuotes( $escapeChar ) . ' ';
2727 public function anyChar() {
2728 return new LikeMatch( '_' );
2731 public function anyString() {
2732 return new LikeMatch( '%' );
2735 public function nextSequenceValue( $seqName ) {
2740 * USE INDEX clause. Unlikely to be useful for anything but MySQL. This
2741 * is only needed because a) MySQL must be as efficient as possible due to
2742 * its use on Wikipedia, and b) MySQL 4.0 is kind of dumb sometimes about
2743 * which index to pick. Anyway, other databases might have different
2744 * indexes on a given table. So don't bother overriding this unless you're
2746 * @param string $index
2749 public function useIndexClause( $index ) {
2754 * IGNORE INDEX clause. Unlikely to be useful for anything but MySQL. This
2755 * is only needed because a) MySQL must be as efficient as possible due to
2756 * its use on Wikipedia, and b) MySQL 4.0 is kind of dumb sometimes about
2757 * which index to pick. Anyway, other databases might have different
2758 * indexes on a given table. So don't bother overriding this unless you're
2760 * @param string $index
2763 public function ignoreIndexClause( $index ) {
2767 public function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__
) {
2768 if ( count( $rows ) == 0 ) {
2773 if ( !is_array( reset( $rows ) ) ) {
2778 $this->startAtomic( $fname, self
::ATOMIC_CANCELABLE
);
2779 $affectedRowCount = 0;
2780 foreach ( $rows as $row ) {
2781 // Delete rows which collide with this one
2782 $indexWhereClauses = [];
2783 foreach ( $uniqueIndexes as $index ) {
2784 $indexColumns = (array)$index;
2785 $indexRowValues = array_intersect_key( $row, array_flip( $indexColumns ) );
2786 if ( count( $indexRowValues ) != count( $indexColumns ) ) {
2787 throw new DBUnexpectedError(
2789 'New record does not provide all values for unique key (' .
2790 implode( ', ', $indexColumns ) . ')'
2792 } elseif ( in_array( null, $indexRowValues, true ) ) {
2793 throw new DBUnexpectedError(
2795 'New record has a null value for unique key (' .
2796 implode( ', ', $indexColumns ) . ')'
2799 $indexWhereClauses[] = $this->makeList( $indexRowValues, LIST_AND
);
2802 if ( $indexWhereClauses ) {
2803 $this->delete( $table, $this->makeList( $indexWhereClauses, LIST_OR
), $fname );
2804 $affectedRowCount +
= $this->affectedRows();
2807 // Now insert the row
2808 $this->insert( $table, $row, $fname );
2809 $affectedRowCount +
= $this->affectedRows();
2811 $this->endAtomic( $fname );
2812 $this->affectedRowCount
= $affectedRowCount;
2813 } catch ( Exception
$e ) {
2814 $this->cancelAtomic( $fname );
2820 * REPLACE query wrapper for MySQL and SQLite, which have a native REPLACE
2823 * @param string $table Table name
2824 * @param array|string $rows Row(s) to insert
2825 * @param string $fname Caller function name
2827 * @return ResultWrapper
2829 protected function nativeReplace( $table, $rows, $fname ) {
2830 $table = $this->tableName( $table );
2833 if ( !is_array( reset( $rows ) ) ) {
2837 $sql = "REPLACE INTO $table (" . implode( ',', array_keys( $rows[0] ) ) . ') VALUES ';
2840 foreach ( $rows as $row ) {
2847 $sql .= '(' . $this->makeList( $row ) . ')';
2850 return $this->query( $sql, $fname );
2853 public function upsert( $table, array $rows, array $uniqueIndexes, array $set,
2856 if ( !count( $rows ) ) {
2857 return true; // nothing to do
2860 if ( !is_array( reset( $rows ) ) ) {
2864 if ( count( $uniqueIndexes ) ) {
2865 $clauses = []; // list WHERE clauses that each identify a single row
2866 foreach ( $rows as $row ) {
2867 foreach ( $uniqueIndexes as $index ) {
2868 $index = is_array( $index ) ?
$index : [ $index ]; // columns
2869 $rowKey = []; // unique key to this row
2870 foreach ( $index as $column ) {
2871 $rowKey[$column] = $row[$column];
2873 $clauses[] = $this->makeList( $rowKey, self
::LIST_AND
);
2876 $where = [ $this->makeList( $clauses, self
::LIST_OR
) ];
2881 $affectedRowCount = 0;
2883 $this->startAtomic( $fname, self
::ATOMIC_CANCELABLE
);
2884 # Update any existing conflicting row(s)
2885 if ( $where !== false ) {
2886 $ok = $this->update( $table, $set, $where, $fname );
2887 $affectedRowCount +
= $this->affectedRows();
2891 # Now insert any non-conflicting row(s)
2892 $ok = $this->insert( $table, $rows, $fname, [ 'IGNORE' ] ) && $ok;
2893 $affectedRowCount +
= $this->affectedRows();
2894 $this->endAtomic( $fname );
2895 $this->affectedRowCount
= $affectedRowCount;
2896 } catch ( Exception
$e ) {
2897 $this->cancelAtomic( $fname );
2904 public function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds,
2908 throw new DBUnexpectedError( $this, __METHOD__
. ' called with empty $conds' );
2911 $delTable = $this->tableName( $delTable );
2912 $joinTable = $this->tableName( $joinTable );
2913 $sql = "DELETE FROM $delTable WHERE $delVar IN (SELECT $joinVar FROM $joinTable ";
2914 if ( $conds != '*' ) {
2915 $sql .= 'WHERE ' . $this->makeList( $conds, self
::LIST_AND
);
2919 $this->query( $sql, $fname );
2922 public function textFieldSize( $table, $field ) {
2923 $table = $this->tableName( $table );
2924 $sql = "SHOW COLUMNS FROM $table LIKE \"$field\";";
2925 $res = $this->query( $sql, __METHOD__
);
2926 $row = $this->fetchObject( $res );
2930 if ( preg_match( '/\((.*)\)/', $row->Type
, $m ) ) {
2939 public function delete( $table, $conds, $fname = __METHOD__
) {
2941 throw new DBUnexpectedError( $this, __METHOD__
. ' called with no conditions' );
2944 $table = $this->tableName( $table );
2945 $sql = "DELETE FROM $table";
2947 if ( $conds != '*' ) {
2948 if ( is_array( $conds ) ) {
2949 $conds = $this->makeList( $conds, self
::LIST_AND
);
2951 $sql .= ' WHERE ' . $conds;
2954 return $this->query( $sql, $fname );
2957 final public function insertSelect(
2958 $destTable, $srcTable, $varMap, $conds,
2959 $fname = __METHOD__
, $insertOptions = [], $selectOptions = [], $selectJoinConds = []
2961 static $hints = [ 'NO_AUTO_COLUMNS' ];
2963 $insertOptions = (array)$insertOptions;
2964 $selectOptions = (array)$selectOptions;
2966 if ( $this->cliMode
&& $this->isInsertSelectSafe( $insertOptions, $selectOptions ) ) {
2967 // For massive migrations with downtime, we don't want to select everything
2968 // into memory and OOM, so do all this native on the server side if possible.
2969 return $this->nativeInsertSelect(
2975 array_diff( $insertOptions, $hints ),
2981 return $this->nonNativeInsertSelect(
2987 array_diff( $insertOptions, $hints ),
2994 * @param array $insertOptions INSERT options
2995 * @param array $selectOptions SELECT options
2996 * @return bool Whether an INSERT SELECT with these options will be replication safe
2999 protected function isInsertSelectSafe( array $insertOptions, array $selectOptions ) {
3004 * Implementation of insertSelect() based on select() and insert()
3006 * @see IDatabase::insertSelect()
3008 * @param string $destTable
3009 * @param string|array $srcTable
3010 * @param array $varMap
3011 * @param array $conds
3012 * @param string $fname
3013 * @param array $insertOptions
3014 * @param array $selectOptions
3015 * @param array $selectJoinConds
3018 protected function nonNativeInsertSelect( $destTable, $srcTable, $varMap, $conds,
3019 $fname = __METHOD__
,
3020 $insertOptions = [], $selectOptions = [], $selectJoinConds = []
3022 // For web requests, do a locking SELECT and then INSERT. This puts the SELECT burden
3023 // on only the master (without needing row-based-replication). It also makes it easy to
3024 // know how big the INSERT is going to be.
3026 foreach ( $varMap as $dstColumn => $sourceColumnOrSql ) {
3027 $fields[] = $this->fieldNameWithAlias( $sourceColumnOrSql, $dstColumn );
3029 $selectOptions[] = 'FOR UPDATE';
3030 $res = $this->select(
3031 $srcTable, implode( ',', $fields ), $conds, $fname, $selectOptions, $selectJoinConds
3038 $affectedRowCount = 0;
3039 $this->startAtomic( $fname, self
::ATOMIC_CANCELABLE
);
3042 foreach ( $res as $row ) {
3043 $rows[] = (array)$row;
3045 // Avoid inserts that are too huge
3046 if ( count( $rows ) >= $this->nonNativeInsertSelectBatchSize
) {
3047 $ok = $this->insert( $destTable, $rows, $fname, $insertOptions );
3051 $affectedRowCount +
= $this->affectedRows();
3055 if ( $rows && $ok ) {
3056 $ok = $this->insert( $destTable, $rows, $fname, $insertOptions );
3058 $affectedRowCount +
= $this->affectedRows();
3062 $this->endAtomic( $fname );
3063 $this->affectedRowCount
= $affectedRowCount;
3065 $this->cancelAtomic( $fname );
3068 } catch ( Exception
$e ) {
3069 $this->cancelAtomic( $fname );
3075 * Native server-side implementation of insertSelect() for situations where
3076 * we don't want to select everything into memory
3078 * @see IDatabase::insertSelect()
3079 * @param string $destTable
3080 * @param string|array $srcTable
3081 * @param array $varMap
3082 * @param array $conds
3083 * @param string $fname
3084 * @param array $insertOptions
3085 * @param array $selectOptions
3086 * @param array $selectJoinConds
3089 protected function nativeInsertSelect( $destTable, $srcTable, $varMap, $conds,
3090 $fname = __METHOD__
,
3091 $insertOptions = [], $selectOptions = [], $selectJoinConds = []
3093 $destTable = $this->tableName( $destTable );
3095 if ( !is_array( $insertOptions ) ) {
3096 $insertOptions = [ $insertOptions ];
3099 $insertOptions = $this->makeInsertOptions( $insertOptions );
3101 $selectSql = $this->selectSQLText(
3103 array_values( $varMap ),
3110 $sql = "INSERT $insertOptions" .
3111 " INTO $destTable (" . implode( ',', array_keys( $varMap ) ) . ') ' .
3114 return $this->query( $sql, $fname );
3118 * Construct a LIMIT query with optional offset. This is used for query
3119 * pages. The SQL should be adjusted so that only the first $limit rows
3120 * are returned. If $offset is provided as well, then the first $offset
3121 * rows should be discarded, and the next $limit rows should be returned.
3122 * If the result of the query is not ordered, then the rows to be returned
3123 * are theoretically arbitrary.
3125 * $sql is expected to be a SELECT, if that makes a difference.
3127 * The version provided by default works in MySQL and SQLite. It will very
3128 * likely need to be overridden for most other DBMSes.
3130 * @param string $sql SQL query we will append the limit too
3131 * @param int $limit The SQL limit
3132 * @param int|bool $offset The SQL offset (default false)
3133 * @throws DBUnexpectedError
3136 public function limitResult( $sql, $limit, $offset = false ) {
3137 if ( !is_numeric( $limit ) ) {
3138 throw new DBUnexpectedError( $this,
3139 "Invalid non-numeric limit passed to limitResult()\n" );
3142 return "$sql LIMIT "
3143 . ( ( is_numeric( $offset ) && $offset != 0 ) ?
"{$offset}," : "" )
3147 public function unionSupportsOrderAndLimit() {
3148 return true; // True for almost every DB supported
3151 public function unionQueries( $sqls, $all ) {
3152 $glue = $all ?
') UNION ALL (' : ') UNION (';
3154 return '(' . implode( $glue, $sqls ) . ')';
3157 public function unionConditionPermutations(
3158 $table, $vars, array $permute_conds, $extra_conds = '', $fname = __METHOD__
,
3159 $options = [], $join_conds = []
3161 // First, build the Cartesian product of $permute_conds
3163 foreach ( $permute_conds as $field => $values ) {
3165 // Skip empty $values
3168 $values = array_unique( $values ); // For sanity
3170 foreach ( $conds as $cond ) {
3171 foreach ( $values as $value ) {
3172 $cond[$field] = $value;
3173 $newConds[] = $cond; // Arrays are by-value, not by-reference, so this works
3179 $extra_conds = $extra_conds === '' ?
[] : (array)$extra_conds;
3181 // If there's just one condition and no subordering, hand off to
3182 // selectSQLText directly.
3183 if ( count( $conds ) === 1 &&
3184 ( !isset( $options['INNER ORDER BY'] ) ||
!$this->unionSupportsOrderAndLimit() )
3186 return $this->selectSQLText(
3187 $table, $vars, $conds[0] +
$extra_conds, $fname, $options, $join_conds
3191 // Otherwise, we need to pull out the order and limit to apply after
3192 // the union. Then build the SQL queries for each set of conditions in
3193 // $conds. Then union them together (using UNION ALL, because the
3194 // product *should* already be distinct).
3195 $orderBy = $this->makeOrderBy( $options );
3196 $limit = $options['LIMIT'] ??
null;
3197 $offset = $options['OFFSET'] ??
false;
3198 $all = empty( $options['NOTALL'] ) && !in_array( 'NOTALL', $options );
3199 if ( !$this->unionSupportsOrderAndLimit() ) {
3200 unset( $options['ORDER BY'], $options['LIMIT'], $options['OFFSET'] );
3202 if ( array_key_exists( 'INNER ORDER BY', $options ) ) {
3203 $options['ORDER BY'] = $options['INNER ORDER BY'];
3205 if ( $limit !== null && is_numeric( $offset ) && $offset != 0 ) {
3206 // We need to increase the limit by the offset rather than
3207 // using the offset directly, otherwise it'll skip incorrectly
3208 // in the subqueries.
3209 $options['LIMIT'] = $limit +
$offset;
3210 unset( $options['OFFSET'] );
3215 foreach ( $conds as $cond ) {
3216 $sqls[] = $this->selectSQLText(
3217 $table, $vars, $cond +
$extra_conds, $fname, $options, $join_conds
3220 $sql = $this->unionQueries( $sqls, $all ) . $orderBy;
3221 if ( $limit !== null ) {
3222 $sql = $this->limitResult( $sql, $limit, $offset );
3228 public function conditional( $cond, $trueVal, $falseVal ) {
3229 if ( is_array( $cond ) ) {
3230 $cond = $this->makeList( $cond, self
::LIST_AND
);
3233 return " (CASE WHEN $cond THEN $trueVal ELSE $falseVal END) ";
3236 public function strreplace( $orig, $old, $new ) {
3237 return "REPLACE({$orig}, {$old}, {$new})";
3240 public function getServerUptime() {
3244 public function wasDeadlock() {
3248 public function wasLockTimeout() {
3252 public function wasConnectionLoss() {
3253 return $this->wasConnectionError( $this->lastErrno() );
3256 public function wasReadOnlyError() {
3260 public function wasErrorReissuable() {
3262 $this->wasDeadlock() ||
3263 $this->wasLockTimeout() ||
3264 $this->wasConnectionLoss()
3269 * Do not use this method outside of Database/DBError classes
3271 * @param int|string $errno
3272 * @return bool Whether the given query error was a connection drop
3274 public function wasConnectionError( $errno ) {
3279 * @return bool Whether it is safe to assume the given error only caused statement rollback
3280 * @note This is for backwards compatibility for callers catching DBError exceptions in
3281 * order to ignore problems like duplicate key errors or foriegn key violations
3284 protected function wasKnownStatementRollbackError() {
3285 return false; // don't know; it could have caused a transaction rollback
3288 public function deadlockLoop() {
3289 $args = func_get_args();
3290 $function = array_shift( $args );
3291 $tries = self
::DEADLOCK_TRIES
;
3293 $this->begin( __METHOD__
);
3296 /** @var Exception $e */
3300 $retVal = $function( ...$args );
3302 } catch ( DBQueryError
$e ) {
3303 if ( $this->wasDeadlock() ) {
3304 // Retry after a randomized delay
3305 usleep( mt_rand( self
::DEADLOCK_DELAY_MIN
, self
::DEADLOCK_DELAY_MAX
) );
3307 // Throw the error back up
3311 } while ( --$tries > 0 );
3313 if ( $tries <= 0 ) {
3314 // Too many deadlocks; give up
3315 $this->rollback( __METHOD__
);
3318 $this->commit( __METHOD__
);
3324 public function masterPosWait( DBMasterPos
$pos, $timeout ) {
3325 # Real waits are implemented in the subclass.
3329 public function getReplicaPos() {
3334 public function getMasterPos() {
3339 public function serverIsReadOnly() {
3343 final public function onTransactionResolution( callable
$callback, $fname = __METHOD__
) {
3344 if ( !$this->trxLevel
) {
3345 throw new DBUnexpectedError( $this, "No transaction is active." );
3347 $this->trxEndCallbacks
[] = [ $callback, $fname, $this->currentAtomicSectionId() ];
3350 final public function onTransactionCommitOrIdle( callable
$callback, $fname = __METHOD__
) {
3351 if ( !$this->trxLevel
&& $this->getTransactionRoundId() ) {
3352 // Start an implicit transaction similar to how query() does
3353 $this->begin( __METHOD__
, self
::TRANSACTION_INTERNAL
);
3354 $this->trxAutomatic
= true;
3357 $this->trxIdleCallbacks
[] = [ $callback, $fname, $this->currentAtomicSectionId() ];
3358 if ( !$this->trxLevel
) {
3359 $this->runOnTransactionIdleCallbacks( self
::TRIGGER_IDLE
);
3363 final public function onTransactionIdle( callable
$callback, $fname = __METHOD__
) {
3364 $this->onTransactionCommitOrIdle( $callback, $fname );
3367 final public function onTransactionPreCommitOrIdle( callable
$callback, $fname = __METHOD__
) {
3368 if ( !$this->trxLevel
&& $this->getTransactionRoundId() ) {
3369 // Start an implicit transaction similar to how query() does
3370 $this->begin( __METHOD__
, self
::TRANSACTION_INTERNAL
);
3371 $this->trxAutomatic
= true;
3374 if ( $this->trxLevel
) {
3375 $this->trxPreCommitCallbacks
[] = [ $callback, $fname, $this->currentAtomicSectionId() ];
3377 // No transaction is active nor will start implicitly, so make one for this callback
3378 $this->startAtomic( __METHOD__
, self
::ATOMIC_CANCELABLE
);
3381 $this->endAtomic( __METHOD__
);
3382 } catch ( Exception
$e ) {
3383 $this->cancelAtomic( __METHOD__
);
3390 * @return AtomicSectionIdentifier|null ID of the topmost atomic section level
3392 private function currentAtomicSectionId() {
3393 if ( $this->trxLevel
&& $this->trxAtomicLevels
) {
3394 $levelInfo = end( $this->trxAtomicLevels
);
3396 return $levelInfo[1];
3403 * @param AtomicSectionIdentifier $old
3404 * @param AtomicSectionIdentifier $new
3406 private function reassignCallbacksForSection(
3407 AtomicSectionIdentifier
$old, AtomicSectionIdentifier
$new
3409 foreach ( $this->trxPreCommitCallbacks
as $key => $info ) {
3410 if ( $info[2] === $old ) {
3411 $this->trxPreCommitCallbacks
[$key][2] = $new;
3414 foreach ( $this->trxIdleCallbacks
as $key => $info ) {
3415 if ( $info[2] === $old ) {
3416 $this->trxIdleCallbacks
[$key][2] = $new;
3419 foreach ( $this->trxEndCallbacks
as $key => $info ) {
3420 if ( $info[2] === $old ) {
3421 $this->trxEndCallbacks
[$key][2] = $new;
3427 * @param AtomicSectionIdentifier[] $sectionIds ID of an actual savepoint
3428 * @throws UnexpectedValueException
3430 private function modifyCallbacksForCancel( array $sectionIds ) {
3431 // Cancel the "on commit" callbacks owned by this savepoint
3432 $this->trxIdleCallbacks
= array_filter(
3433 $this->trxIdleCallbacks
,
3434 function ( $entry ) use ( $sectionIds ) {
3435 return !in_array( $entry[2], $sectionIds, true );
3438 $this->trxPreCommitCallbacks
= array_filter(
3439 $this->trxPreCommitCallbacks
,
3440 function ( $entry ) use ( $sectionIds ) {
3441 return !in_array( $entry[2], $sectionIds, true );
3444 // Make "on resolution" callbacks owned by this savepoint to perceive a rollback
3445 foreach ( $this->trxEndCallbacks
as $key => $entry ) {
3446 if ( in_array( $entry[2], $sectionIds, true ) ) {
3447 $callback = $entry[0];
3448 $this->trxEndCallbacks
[$key][0] = function () use ( $callback ) {
3449 return $callback( self
::TRIGGER_ROLLBACK
, $this );
3455 final public function setTransactionListener( $name, callable
$callback = null ) {
3457 $this->trxRecurringCallbacks
[$name] = $callback;
3459 unset( $this->trxRecurringCallbacks
[$name] );
3464 * Whether to disable running of post-COMMIT/ROLLBACK callbacks
3466 * This method should not be used outside of Database/LoadBalancer
3468 * @param bool $suppress
3471 final public function setTrxEndCallbackSuppression( $suppress ) {
3472 $this->trxEndCallbacksSuppressed
= $suppress;
3476 * Actually consume and run any "on transaction idle/resolution" callbacks.
3478 * This method should not be used outside of Database/LoadBalancer
3480 * @param int $trigger IDatabase::TRIGGER_* constant
3481 * @return int Number of callbacks attempted
3485 public function runOnTransactionIdleCallbacks( $trigger ) {
3486 if ( $this->trxLevel
) { // sanity
3487 throw new DBUnexpectedError( $this, __METHOD__
. ': a transaction is still open.' );
3490 if ( $this->trxEndCallbacksSuppressed
) {
3495 $autoTrx = $this->getFlag( self
::DBO_TRX
); // automatic begin() enabled?
3496 /** @var Exception $e */
3497 $e = null; // first exception
3498 do { // callbacks may add callbacks :)
3499 $callbacks = array_merge(
3500 $this->trxIdleCallbacks
,
3501 $this->trxEndCallbacks
// include "transaction resolution" callbacks
3503 $this->trxIdleCallbacks
= []; // consumed (and recursion guard)
3504 $this->trxEndCallbacks
= []; // consumed (recursion guard)
3505 foreach ( $callbacks as $callback ) {
3507 list( $phpCallback ) = $callback;
3508 $this->clearFlag( self
::DBO_TRX
); // make each query its own transaction
3510 call_user_func( $phpCallback, $trigger, $this );
3511 } catch ( Exception
$ex ) {
3512 call_user_func( $this->errorLogger
, $ex );
3514 // Some callbacks may use startAtomic/endAtomic, so make sure
3515 // their transactions are ended so other callbacks don't fail
3516 if ( $this->trxLevel() ) {
3517 $this->rollback( __METHOD__
, self
::FLUSHING_INTERNAL
);
3521 $this->setFlag( self
::DBO_TRX
); // restore automatic begin()
3523 $this->clearFlag( self
::DBO_TRX
); // restore auto-commit
3527 } while ( count( $this->trxIdleCallbacks
) );
3529 if ( $e instanceof Exception
) {
3530 throw $e; // re-throw any first exception
3537 * Actually consume and run any "on transaction pre-commit" callbacks.
3539 * This method should not be used outside of Database/LoadBalancer
3542 * @return int Number of callbacks attempted
3545 public function runOnTransactionPreCommitCallbacks() {
3548 $e = null; // first exception
3549 do { // callbacks may add callbacks :)
3550 $callbacks = $this->trxPreCommitCallbacks
;
3551 $this->trxPreCommitCallbacks
= []; // consumed (and recursion guard)
3552 foreach ( $callbacks as $callback ) {
3555 list( $phpCallback ) = $callback;
3556 $phpCallback( $this );
3557 } catch ( Exception
$ex ) {
3558 ( $this->errorLogger
)( $ex );
3562 } while ( count( $this->trxPreCommitCallbacks
) );
3564 if ( $e instanceof Exception
) {
3565 throw $e; // re-throw any first exception
3572 * Actually run any "transaction listener" callbacks.
3574 * This method should not be used outside of Database/LoadBalancer
3576 * @param int $trigger IDatabase::TRIGGER_* constant
3580 public function runTransactionListenerCallbacks( $trigger ) {
3581 if ( $this->trxEndCallbacksSuppressed
) {
3585 /** @var Exception $e */
3586 $e = null; // first exception
3588 foreach ( $this->trxRecurringCallbacks
as $phpCallback ) {
3590 $phpCallback( $trigger, $this );
3591 } catch ( Exception
$ex ) {
3592 ( $this->errorLogger
)( $ex );
3597 if ( $e instanceof Exception
) {
3598 throw $e; // re-throw any first exception
3603 * Create a savepoint
3605 * This is used internally to implement atomic sections. It should not be
3609 * @param string $identifier Identifier for the savepoint
3610 * @param string $fname Calling function name
3612 protected function doSavepoint( $identifier, $fname ) {
3613 $this->query( 'SAVEPOINT ' . $this->addIdentifierQuotes( $identifier ), $fname );
3617 * Release a savepoint
3619 * This is used internally to implement atomic sections. It should not be
3623 * @param string $identifier Identifier for the savepoint
3624 * @param string $fname Calling function name
3626 protected function doReleaseSavepoint( $identifier, $fname ) {
3627 $this->query( 'RELEASE SAVEPOINT ' . $this->addIdentifierQuotes( $identifier ), $fname );
3631 * Rollback to a savepoint
3633 * This is used internally to implement atomic sections. It should not be
3637 * @param string $identifier Identifier for the savepoint
3638 * @param string $fname Calling function name
3640 protected function doRollbackToSavepoint( $identifier, $fname ) {
3641 $this->query( 'ROLLBACK TO SAVEPOINT ' . $this->addIdentifierQuotes( $identifier ), $fname );
3645 * @param string $fname
3648 private function nextSavepointId( $fname ) {
3649 $savepointId = self
::$SAVEPOINT_PREFIX . ++
$this->trxAtomicCounter
;
3650 if ( strlen( $savepointId ) > 30 ) {
3651 // 30 == Oracle's identifier length limit (pre 12c)
3652 // With a 22 character prefix, that puts the highest number at 99999999.
3653 throw new DBUnexpectedError(
3655 'There have been an excessively large number of atomic sections in a transaction'
3656 . " started by $this->trxFname (at $fname)"
3660 return $savepointId;
3663 final public function startAtomic(
3664 $fname = __METHOD__
, $cancelable = self
::ATOMIC_NOT_CANCELABLE
3666 $savepointId = $cancelable === self
::ATOMIC_CANCELABLE ? self
::$NOT_APPLICABLE : null;
3668 if ( !$this->trxLevel
) {
3669 $this->begin( $fname, self
::TRANSACTION_INTERNAL
); // sets trxAutomatic
3670 // If DBO_TRX is set, a series of startAtomic/endAtomic pairs will result
3671 // in all changes being in one transaction to keep requests transactional.
3672 if ( $this->getFlag( self
::DBO_TRX
) ) {
3673 // Since writes could happen in between the topmost atomic sections as part
3674 // of the transaction, those sections will need savepoints.
3675 $savepointId = $this->nextSavepointId( $fname );
3676 $this->doSavepoint( $savepointId, $fname );
3678 $this->trxAutomaticAtomic
= true;
3680 } elseif ( $cancelable === self
::ATOMIC_CANCELABLE
) {
3681 $savepointId = $this->nextSavepointId( $fname );
3682 $this->doSavepoint( $savepointId, $fname );
3685 $sectionId = new AtomicSectionIdentifier
;
3686 $this->trxAtomicLevels
[] = [ $fname, $sectionId, $savepointId ];
3691 final public function endAtomic( $fname = __METHOD__
) {
3692 if ( !$this->trxLevel ||
!$this->trxAtomicLevels
) {
3693 throw new DBUnexpectedError( $this, "No atomic section is open (got $fname)." );
3696 // Check if the current section matches $fname
3697 $pos = count( $this->trxAtomicLevels
) - 1;
3698 list( $savedFname, $sectionId, $savepointId ) = $this->trxAtomicLevels
[$pos];
3700 if ( $savedFname !== $fname ) {
3701 throw new DBUnexpectedError(
3703 "Invalid atomic section ended (got $fname but expected $savedFname)."
3707 // Remove the last section (no need to re-index the array)
3708 array_pop( $this->trxAtomicLevels
);
3710 if ( !$this->trxAtomicLevels
&& $this->trxAutomaticAtomic
) {
3711 $this->commit( $fname, self
::FLUSHING_INTERNAL
);
3712 } elseif ( $savepointId !== null && $savepointId !== self
::$NOT_APPLICABLE ) {
3713 $this->doReleaseSavepoint( $savepointId, $fname );
3716 // Hoist callback ownership for callbacks in the section that just ended;
3717 // all callbacks should have an owner that is present in trxAtomicLevels.
3718 $currentSectionId = $this->currentAtomicSectionId();
3719 if ( $currentSectionId ) {
3720 $this->reassignCallbacksForSection( $sectionId, $currentSectionId );
3724 final public function cancelAtomic(
3725 $fname = __METHOD__
, AtomicSectionIdentifier
$sectionId = null
3727 if ( !$this->trxLevel ||
!$this->trxAtomicLevels
) {
3728 throw new DBUnexpectedError( $this, "No atomic section is open (got $fname)." );
3731 if ( $sectionId !== null ) {
3732 // Find the (last) section with the given $sectionId
3734 foreach ( $this->trxAtomicLevels
as $i => list( $asFname, $asId, $spId ) ) {
3735 if ( $asId === $sectionId ) {
3740 throw new DBUnexpectedError( "Atomic section not found (for $fname)" );
3742 // Remove all descendant sections and re-index the array
3744 $len = count( $this->trxAtomicLevels
);
3745 for ( $i = $pos +
1; $i < $len; ++
$i ) {
3746 $excisedIds[] = $this->trxAtomicLevels
[$i][1];
3748 $this->trxAtomicLevels
= array_slice( $this->trxAtomicLevels
, 0, $pos +
1 );
3749 $this->modifyCallbacksForCancel( $excisedIds );
3752 // Check if the current section matches $fname
3753 $pos = count( $this->trxAtomicLevels
) - 1;
3754 list( $savedFname, $savedSectionId, $savepointId ) = $this->trxAtomicLevels
[$pos];
3756 if ( $savedFname !== $fname ) {
3757 throw new DBUnexpectedError(
3759 "Invalid atomic section ended (got $fname but expected $savedFname)."
3763 // Remove the last section (no need to re-index the array)
3764 array_pop( $this->trxAtomicLevels
);
3765 $this->modifyCallbacksForCancel( [ $savedSectionId ] );
3767 if ( $savepointId !== null ) {
3768 // Rollback the transaction to the state just before this atomic section
3769 if ( $savepointId === self
::$NOT_APPLICABLE ) {
3770 $this->rollback( $fname, self
::FLUSHING_INTERNAL
);
3772 $this->doRollbackToSavepoint( $savepointId, $fname );
3773 $this->trxStatus
= self
::STATUS_TRX_OK
; // no exception; recovered
3774 $this->trxStatusIgnoredCause
= null;
3776 } elseif ( $this->trxStatus
> self
::STATUS_TRX_ERROR
) {
3777 // Put the transaction into an error state if it's not already in one
3778 $this->trxStatus
= self
::STATUS_TRX_ERROR
;
3779 $this->trxStatusCause
= new DBUnexpectedError(
3781 "Uncancelable atomic section canceled (got $fname)."
3785 $this->affectedRowCount
= 0; // for the sake of consistency
3788 final public function doAtomicSection(
3789 $fname, callable
$callback, $cancelable = self
::ATOMIC_NOT_CANCELABLE
3791 $sectionId = $this->startAtomic( $fname, $cancelable );
3793 $res = $callback( $this, $fname );
3794 } catch ( Exception
$e ) {
3795 $this->cancelAtomic( $fname, $sectionId );
3799 $this->endAtomic( $fname );
3804 final public function begin( $fname = __METHOD__
, $mode = self
::TRANSACTION_EXPLICIT
) {
3805 static $modes = [ self
::TRANSACTION_EXPLICIT
, self
::TRANSACTION_INTERNAL
];
3806 if ( !in_array( $mode, $modes, true ) ) {
3807 throw new DBUnexpectedError( $this, "$fname: invalid mode parameter '$mode'." );
3810 // Protect against mismatched atomic section, transaction nesting, and snapshot loss
3811 if ( $this->trxLevel
) {
3812 if ( $this->trxAtomicLevels
) {
3813 $levels = $this->flatAtomicSectionList();
3814 $msg = "$fname: Got explicit BEGIN while atomic section(s) $levels are open.";
3815 throw new DBUnexpectedError( $this, $msg );
3816 } elseif ( !$this->trxAutomatic
) {
3817 $msg = "$fname: Explicit transaction already active (from {$this->trxFname}).";
3818 throw new DBUnexpectedError( $this, $msg );
3820 $msg = "$fname: Implicit transaction already active (from {$this->trxFname}).";
3821 throw new DBUnexpectedError( $this, $msg );
3823 } elseif ( $this->getFlag( self
::DBO_TRX
) && $mode !== self
::TRANSACTION_INTERNAL
) {
3824 $msg = "$fname: Implicit transaction expected (DBO_TRX set).";
3825 throw new DBUnexpectedError( $this, $msg );
3828 // Avoid fatals if close() was called
3829 $this->assertOpen();
3831 $this->doBegin( $fname );
3832 $this->trxStatus
= self
::STATUS_TRX_OK
;
3833 $this->trxStatusIgnoredCause
= null;
3834 $this->trxAtomicCounter
= 0;
3835 $this->trxTimestamp
= microtime( true );
3836 $this->trxFname
= $fname;
3837 $this->trxDoneWrites
= false;
3838 $this->trxAutomaticAtomic
= false;
3839 $this->trxAtomicLevels
= [];
3840 $this->trxShortId
= sprintf( '%06x', mt_rand( 0, 0xffffff ) );
3841 $this->trxWriteDuration
= 0.0;
3842 $this->trxWriteQueryCount
= 0;
3843 $this->trxWriteAffectedRows
= 0;
3844 $this->trxWriteAdjDuration
= 0.0;
3845 $this->trxWriteAdjQueryCount
= 0;
3846 $this->trxWriteCallers
= [];
3847 // First SELECT after BEGIN will establish the snapshot in REPEATABLE-READ.
3848 // Get an estimate of the replication lag before any such queries.
3849 $this->trxReplicaLag
= null; // clear cached value first
3850 $this->trxReplicaLag
= $this->getApproximateLagStatus()['lag'];
3851 // T147697: make explicitTrxActive() return true until begin() finishes. This way, no
3852 // caller will think its OK to muck around with the transaction just because startAtomic()
3853 // has not yet completed (e.g. setting trxAtomicLevels).
3854 $this->trxAutomatic
= ( $mode === self
::TRANSACTION_INTERNAL
);
3858 * Issues the BEGIN command to the database server.
3860 * @see Database::begin()
3861 * @param string $fname
3863 protected function doBegin( $fname ) {
3864 $this->query( 'BEGIN', $fname );
3865 $this->trxLevel
= 1;
3868 final public function commit( $fname = __METHOD__
, $flush = self
::FLUSHING_ONE
) {
3869 static $modes = [ self
::FLUSHING_ONE
, self
::FLUSHING_ALL_PEERS
, self
::FLUSHING_INTERNAL
];
3870 if ( !in_array( $flush, $modes, true ) ) {
3871 throw new DBUnexpectedError( $this, "$fname: invalid flush parameter '$flush'." );
3874 if ( $this->trxLevel
&& $this->trxAtomicLevels
) {
3875 // There are still atomic sections open; this cannot be ignored
3876 $levels = $this->flatAtomicSectionList();
3877 throw new DBUnexpectedError(
3879 "$fname: Got COMMIT while atomic sections $levels are still open."
3883 if ( $flush === self
::FLUSHING_INTERNAL ||
$flush === self
::FLUSHING_ALL_PEERS
) {
3884 if ( !$this->trxLevel
) {
3885 return; // nothing to do
3886 } elseif ( !$this->trxAutomatic
) {
3887 throw new DBUnexpectedError(
3889 "$fname: Flushing an explicit transaction, getting out of sync."
3893 if ( !$this->trxLevel
) {
3894 $this->queryLogger
->error(
3895 "$fname: No transaction to commit, something got out of sync." );
3896 return; // nothing to do
3897 } elseif ( $this->trxAutomatic
) {
3898 throw new DBUnexpectedError(
3900 "$fname: Expected mass commit of all peer transactions (DBO_TRX set)."
3905 // Avoid fatals if close() was called
3906 $this->assertOpen();
3908 $this->runOnTransactionPreCommitCallbacks();
3910 $writeTime = $this->pendingWriteQueryDuration( self
::ESTIMATE_DB_APPLY
);
3911 $this->doCommit( $fname );
3912 $this->trxStatus
= self
::STATUS_TRX_NONE
;
3914 if ( $this->trxDoneWrites
) {
3915 $this->lastWriteTime
= microtime( true );
3916 $this->trxProfiler
->transactionWritingOut(
3918 $this->getDomainID(),
3921 $this->trxWriteAffectedRows
3925 // With FLUSHING_ALL_PEERS, callbacks will be explicitly run later
3926 if ( $flush !== self
::FLUSHING_ALL_PEERS
) {
3927 $this->runOnTransactionIdleCallbacks( self
::TRIGGER_COMMIT
);
3928 $this->runTransactionListenerCallbacks( self
::TRIGGER_COMMIT
);
3933 * Issues the COMMIT command to the database server.
3935 * @see Database::commit()
3936 * @param string $fname
3938 protected function doCommit( $fname ) {
3939 if ( $this->trxLevel
) {
3940 $this->query( 'COMMIT', $fname );
3941 $this->trxLevel
= 0;
3945 final public function rollback( $fname = __METHOD__
, $flush = '' ) {
3946 $trxActive = $this->trxLevel
;
3948 if ( $flush !== self
::FLUSHING_INTERNAL
&& $flush !== self
::FLUSHING_ALL_PEERS
) {
3949 if ( $this->getFlag( self
::DBO_TRX
) ) {
3950 throw new DBUnexpectedError(
3952 "$fname: Expected mass rollback of all peer transactions (DBO_TRX set)."
3958 // Avoid fatals if close() was called
3959 $this->assertOpen();
3961 $writeTime = $this->pendingWriteQueryDuration( self
::ESTIMATE_DB_APPLY
);
3962 $this->doRollback( $fname );
3963 $this->trxStatus
= self
::STATUS_TRX_NONE
;
3964 $this->trxAtomicLevels
= [];
3966 if ( $this->trxDoneWrites
) {
3967 $this->trxProfiler
->transactionWritingOut(
3969 $this->getDomainID(),
3972 $this->trxWriteAffectedRows
3977 // Clear any commit-dependant callbacks. They might even be present
3978 // only due to transaction rounds, with no SQL transaction being active
3979 $this->trxIdleCallbacks
= [];
3980 $this->trxPreCommitCallbacks
= [];
3982 // With FLUSHING_ALL_PEERS, callbacks will be explicitly run later
3983 if ( $trxActive && $flush !== self
::FLUSHING_ALL_PEERS
) {
3985 $this->runOnTransactionIdleCallbacks( self
::TRIGGER_ROLLBACK
);
3986 } catch ( Exception
$e ) {
3987 // already logged; finish and let LoadBalancer move on during mass-rollback
3990 $this->runTransactionListenerCallbacks( self
::TRIGGER_ROLLBACK
);
3991 } catch ( Exception
$e ) {
3992 // already logged; let LoadBalancer move on during mass-rollback
3995 $this->affectedRowCount
= 0; // for the sake of consistency
4000 * Issues the ROLLBACK command to the database server.
4002 * @see Database::rollback()
4003 * @param string $fname
4005 protected function doRollback( $fname ) {
4006 if ( $this->trxLevel
) {
4007 # Disconnects cause rollback anyway, so ignore those errors
4008 $ignoreErrors = true;
4009 $this->query( 'ROLLBACK', $fname, $ignoreErrors );
4010 $this->trxLevel
= 0;
4014 public function flushSnapshot( $fname = __METHOD__
) {
4015 if ( $this->writesOrCallbacksPending() ||
$this->explicitTrxActive() ) {
4016 // This only flushes transactions to clear snapshots, not to write data
4017 $fnames = implode( ', ', $this->pendingWriteAndCallbackCallers() );
4018 throw new DBUnexpectedError(
4020 "$fname: Cannot flush snapshot because writes are pending ($fnames)."
4024 $this->commit( $fname, self
::FLUSHING_INTERNAL
);
4027 public function explicitTrxActive() {
4028 return $this->trxLevel
&& ( $this->trxAtomicLevels ||
!$this->trxAutomatic
);
4031 public function duplicateTableStructure(
4032 $oldName, $newName, $temporary = false, $fname = __METHOD__
4034 throw new RuntimeException( __METHOD__
. ' is not implemented in descendant class' );
4037 public function listTables( $prefix = null, $fname = __METHOD__
) {
4038 throw new RuntimeException( __METHOD__
. ' is not implemented in descendant class' );
4041 public function listViews( $prefix = null, $fname = __METHOD__
) {
4042 throw new RuntimeException( __METHOD__
. ' is not implemented in descendant class' );
4045 public function timestamp( $ts = 0 ) {
4046 $t = new ConvertibleTimestamp( $ts );
4047 // Let errors bubble up to avoid putting garbage in the DB
4048 return $t->getTimestamp( TS_MW
);
4051 public function timestampOrNull( $ts = null ) {
4052 if ( is_null( $ts ) ) {
4055 return $this->timestamp( $ts );
4059 public function affectedRows() {
4060 return ( $this->affectedRowCount
=== null )
4061 ?
$this->fetchAffectedRowCount() // default to driver value
4062 : $this->affectedRowCount
;
4066 * @return int Number of retrieved rows according to the driver
4068 abstract protected function fetchAffectedRowCount();
4071 * Take the result from a query, and wrap it in a ResultWrapper if
4072 * necessary. Boolean values are passed through as is, to indicate success
4073 * of write queries or failure.
4075 * Once upon a time, Database::query() returned a bare MySQL result
4076 * resource, and it was necessary to call this function to convert it to
4077 * a wrapper. Nowadays, raw database objects are never exposed to external
4078 * callers, so this is unnecessary in external code.
4080 * @param bool|ResultWrapper|resource $result
4081 * @return bool|ResultWrapper
4083 protected function resultObject( $result ) {
4086 } elseif ( $result instanceof ResultWrapper
) {
4088 } elseif ( $result === true ) {
4089 // Successful write query
4092 return new ResultWrapper( $this, $result );
4096 public function ping( &$rtt = null ) {
4097 // Avoid hitting the server if it was hit recently
4098 if ( $this->isOpen() && ( microtime( true ) - $this->lastPing
) < self
::PING_TTL
) {
4099 if ( !func_num_args() ||
$this->rttEstimate
> 0 ) {
4100 $rtt = $this->rttEstimate
;
4101 return true; // don't care about $rtt
4105 // This will reconnect if possible or return false if not
4106 $this->clearFlag( self
::DBO_TRX
, self
::REMEMBER_PRIOR
);
4107 $ok = ( $this->query( self
::PING_QUERY
, __METHOD__
, true ) !== false );
4108 $this->restoreFlags( self
::RESTORE_PRIOR
);
4111 $rtt = $this->rttEstimate
;
4118 * Close any existing (dead) database connection and open a new connection
4120 * @param string $fname
4121 * @return bool True if new connection is opened successfully, false if error
4123 protected function replaceLostConnection( $fname ) {
4124 $this->closeConnection();
4125 $this->opened
= false;
4126 $this->conn
= false;
4134 $this->tablePrefix()
4136 $this->lastPing
= microtime( true );
4139 $this->connLogger
->warning(
4140 $fname . ': lost connection to {dbserver}; reconnected',
4142 'dbserver' => $this->getServer(),
4143 'trace' => ( new RuntimeException() )->getTraceAsString()
4146 } catch ( DBConnectionError
$e ) {
4149 $this->connLogger
->error(
4150 $fname . ': lost connection to {dbserver} permanently',
4151 [ 'dbserver' => $this->getServer() ]
4155 $this->handleSessionLoss();
4160 public function getSessionLagStatus() {
4161 return $this->getRecordedTransactionLagStatus() ?
: $this->getApproximateLagStatus();
4165 * Get the replica DB lag when the current transaction started
4167 * This is useful when transactions might use snapshot isolation
4168 * (e.g. REPEATABLE-READ in innodb), so the "real" lag of that data
4169 * is this lag plus transaction duration. If they don't, it is still
4170 * safe to be pessimistic. This returns null if there is no transaction.
4172 * This returns null if the lag status for this transaction was not yet recorded.
4174 * @return array|null ('lag': seconds or false on error, 'since': UNIX timestamp of BEGIN)
4177 final protected function getRecordedTransactionLagStatus() {
4178 return ( $this->trxLevel
&& $this->trxReplicaLag
!== null )
4179 ?
[ 'lag' => $this->trxReplicaLag
, 'since' => $this->trxTimestamp() ]
4184 * Get a replica DB lag estimate for this server
4186 * @return array ('lag': seconds or false on error, 'since': UNIX timestamp of estimate)
4189 protected function getApproximateLagStatus() {
4191 'lag' => $this->getLBInfo( 'replica' ) ?
$this->getLag() : 0,
4192 'since' => microtime( true )
4197 * Merge the result of getSessionLagStatus() for several DBs
4198 * using the most pessimistic values to estimate the lag of
4199 * any data derived from them in combination
4201 * This is information is useful for caching modules
4203 * @see WANObjectCache::set()
4204 * @see WANObjectCache::getWithSetCallback()
4206 * @param IDatabase $db1
4207 * @param IDatabase|null $db2 [optional]
4208 * @return array Map of values:
4209 * - lag: highest lag of any of the DBs or false on error (e.g. replication stopped)
4210 * - since: oldest UNIX timestamp of any of the DB lag estimates
4211 * - pending: whether any of the DBs have uncommitted changes
4215 public static function getCacheSetOptions( IDatabase
$db1, IDatabase
$db2 = null ) {
4216 $res = [ 'lag' => 0, 'since' => INF
, 'pending' => false ];
4217 foreach ( func_get_args() as $db ) {
4218 /** @var IDatabase $db */
4219 $status = $db->getSessionLagStatus();
4220 if ( $status['lag'] === false ) {
4221 $res['lag'] = false;
4222 } elseif ( $res['lag'] !== false ) {
4223 $res['lag'] = max( $res['lag'], $status['lag'] );
4225 $res['since'] = min( $res['since'], $status['since'] );
4226 $res['pending'] = $res['pending'] ?
: $db->writesPending();
4232 public function getLag() {
4236 public function maxListLen() {
4240 public function encodeBlob( $b ) {
4244 public function decodeBlob( $b ) {
4245 if ( $b instanceof Blob
) {
4251 public function setSessionOptions( array $options ) {
4254 public function sourceFile(
4256 callable
$lineCallback = null,
4257 callable
$resultCallback = null,
4259 callable
$inputCallback = null
4261 Wikimedia\
suppressWarnings();
4262 $fp = fopen( $filename, 'r' );
4263 Wikimedia\restoreWarnings
();
4265 if ( false === $fp ) {
4266 throw new RuntimeException( "Could not open \"{$filename}\".\n" );
4270 $fname = __METHOD__
. "( $filename )";
4274 $error = $this->sourceStream(
4275 $fp, $lineCallback, $resultCallback, $fname, $inputCallback );
4276 } catch ( Exception
$e ) {
4286 public function setSchemaVars( $vars ) {
4287 $this->schemaVars
= $vars;
4290 public function sourceStream(
4292 callable
$lineCallback = null,
4293 callable
$resultCallback = null,
4294 $fname = __METHOD__
,
4295 callable
$inputCallback = null
4297 $delimiterReset = new ScopedCallback(
4298 function ( $delimiter ) {
4299 $this->delimiter
= $delimiter;
4301 [ $this->delimiter
]
4305 while ( !feof( $fp ) ) {
4306 if ( $lineCallback ) {
4307 call_user_func( $lineCallback );
4310 $line = trim( fgets( $fp ) );
4312 if ( $line == '' ) {
4316 if ( '-' == $line[0] && '-' == $line[1] ) {
4324 $done = $this->streamStatementEnd( $cmd, $line );
4328 if ( $done ||
feof( $fp ) ) {
4329 $cmd = $this->replaceVars( $cmd );
4331 if ( $inputCallback ) {
4332 $callbackResult = $inputCallback( $cmd );
4334 if ( is_string( $callbackResult ) ||
!$callbackResult ) {
4335 $cmd = $callbackResult;
4340 $res = $this->query( $cmd, $fname );
4342 if ( $resultCallback ) {
4343 $resultCallback( $res, $this );
4346 if ( false === $res ) {
4347 $err = $this->lastError();
4349 return "Query \"{$cmd}\" failed with error code \"$err\".\n";
4356 ScopedCallback
::consume( $delimiterReset );
4361 * Called by sourceStream() to check if we've reached a statement end
4363 * @param string &$sql SQL assembled so far
4364 * @param string &$newLine New line about to be added to $sql
4365 * @return bool Whether $newLine contains end of the statement
4367 public function streamStatementEnd( &$sql, &$newLine ) {
4368 if ( $this->delimiter
) {
4370 $newLine = preg_replace(
4371 '/' . preg_quote( $this->delimiter
, '/' ) . '$/', '', $newLine );
4372 if ( $newLine != $prev ) {
4381 * Database independent variable replacement. Replaces a set of variables
4382 * in an SQL statement with their contents as given by $this->getSchemaVars().
4384 * Supports '{$var}' `{$var}` and / *$var* / (without the spaces) style variables.
4386 * - '{$var}' should be used for text and is passed through the database's
4388 * - `{$var}` should be used for identifiers (e.g. table and database names).
4389 * It is passed through the database's addIdentifierQuotes method which
4390 * can be overridden if the database uses something other than backticks.
4391 * - / *_* / or / *$wgDBprefix* / passes the name that follows through the
4392 * database's tableName method.
4393 * - / *i* / passes the name that follows through the database's indexName method.
4394 * - In all other cases, / *$var* / is left unencoded. Except for table options,
4395 * its use should be avoided. In 1.24 and older, string encoding was applied.
4397 * @param string $ins SQL statement to replace variables in
4398 * @return string The new SQL statement with variables replaced
4400 protected function replaceVars( $ins ) {
4401 $vars = $this->getSchemaVars();
4402 return preg_replace_callback(
4404 /\* (\$wgDBprefix|[_i]) \*/ (\w*) | # 1-2. tableName, indexName
4405 \'\{\$ (\w+) }\' | # 3. addQuotes
4406 `\{\$ (\w+) }` | # 4. addIdentifierQuotes
4407 /\*\$ (\w+) \*/ # 5. leave unencoded
4409 function ( $m ) use ( $vars ) {
4410 // Note: Because of <https://bugs.php.net/bug.php?id=51881>,
4411 // check for both nonexistent keys *and* the empty string.
4412 if ( isset( $m[1] ) && $m[1] !== '' ) {
4413 if ( $m[1] === 'i' ) {
4414 return $this->indexName( $m[2] );
4416 return $this->tableName( $m[2] );
4418 } elseif ( isset( $m[3] ) && $m[3] !== '' && array_key_exists( $m[3], $vars ) ) {
4419 return $this->addQuotes( $vars[$m[3]] );
4420 } elseif ( isset( $m[4] ) && $m[4] !== '' && array_key_exists( $m[4], $vars ) ) {
4421 return $this->addIdentifierQuotes( $vars[$m[4]] );
4422 } elseif ( isset( $m[5] ) && $m[5] !== '' && array_key_exists( $m[5], $vars ) ) {
4423 return $vars[$m[5]];
4433 * Get schema variables. If none have been set via setSchemaVars(), then
4434 * use some defaults from the current object.
4438 protected function getSchemaVars() {
4439 if ( $this->schemaVars
) {
4440 return $this->schemaVars
;
4442 return $this->getDefaultSchemaVars();
4447 * Get schema variables to use if none have been set via setSchemaVars().
4449 * Override this in derived classes to provide variables for tables.sql
4450 * and SQL patch files.
4454 protected function getDefaultSchemaVars() {
4458 public function lockIsFree( $lockName, $method ) {
4459 // RDBMs methods for checking named locks may or may not count this thread itself.
4460 // In MySQL, IS_FREE_LOCK() returns 0 if the thread already has the lock. This is
4461 // the behavior choosen by the interface for this method.
4462 return !isset( $this->namedLocksHeld
[$lockName] );
4465 public function lock( $lockName, $method, $timeout = 5 ) {
4466 $this->namedLocksHeld
[$lockName] = 1;
4471 public function unlock( $lockName, $method ) {
4472 unset( $this->namedLocksHeld
[$lockName] );
4477 public function getScopedLockAndFlush( $lockKey, $fname, $timeout ) {
4478 if ( $this->writesOrCallbacksPending() ) {
4479 // This only flushes transactions to clear snapshots, not to write data
4480 $fnames = implode( ', ', $this->pendingWriteAndCallbackCallers() );
4481 throw new DBUnexpectedError(
4483 "$fname: Cannot flush pre-lock snapshot because writes are pending ($fnames)."
4487 if ( !$this->lock( $lockKey, $fname, $timeout ) ) {
4491 $unlocker = new ScopedCallback( function () use ( $lockKey, $fname ) {
4492 if ( $this->trxLevel() ) {
4493 // There is a good chance an exception was thrown, causing any early return
4494 // from the caller. Let any error handler get a chance to issue rollback().
4495 // If there isn't one, let the error bubble up and trigger server-side rollback.
4496 $this->onTransactionResolution(
4497 function () use ( $lockKey, $fname ) {
4498 $this->unlock( $lockKey, $fname );
4503 $this->unlock( $lockKey, $fname );
4507 $this->commit( $fname, self
::FLUSHING_INTERNAL
);
4512 public function namedLocksEnqueue() {
4516 public function tableLocksHaveTransactionScope() {
4520 final public function lockTables( array $read, array $write, $method ) {
4521 if ( $this->writesOrCallbacksPending() ) {
4522 throw new DBUnexpectedError( $this, "Transaction writes or callbacks still pending." );
4525 if ( $this->tableLocksHaveTransactionScope() ) {
4526 $this->startAtomic( $method );
4529 return $this->doLockTables( $read, $write, $method );
4533 * Helper function for lockTables() that handles the actual table locking
4535 * @param array $read Array of tables to lock for read access
4536 * @param array $write Array of tables to lock for write access
4537 * @param string $method Name of caller
4540 protected function doLockTables( array $read, array $write, $method ) {
4544 final public function unlockTables( $method ) {
4545 if ( $this->tableLocksHaveTransactionScope() ) {
4546 $this->endAtomic( $method );
4548 return true; // locks released on COMMIT/ROLLBACK
4551 return $this->doUnlockTables( $method );
4555 * Helper function for unlockTables() that handles the actual table unlocking
4557 * @param string $method Name of caller
4560 protected function doUnlockTables( $method ) {
4566 * @param string $tableName
4567 * @param string $fName
4568 * @return bool|ResultWrapper
4571 public function dropTable( $tableName, $fName = __METHOD__
) {
4572 if ( !$this->tableExists( $tableName, $fName ) ) {
4575 $sql = "DROP TABLE " . $this->tableName( $tableName ) . " CASCADE";
4577 return $this->query( $sql, $fName );
4580 public function getInfinity() {
4584 public function encodeExpiry( $expiry ) {
4585 return ( $expiry == '' ||
$expiry == 'infinity' ||
$expiry == $this->getInfinity() )
4586 ?
$this->getInfinity()
4587 : $this->timestamp( $expiry );
4590 public function decodeExpiry( $expiry, $format = TS_MW
) {
4591 if ( $expiry == '' ||
$expiry == 'infinity' ||
$expiry == $this->getInfinity() ) {
4595 return ConvertibleTimestamp
::convert( $format, $expiry );
4598 public function setBigSelects( $value = true ) {
4602 public function isReadOnly() {
4603 return ( $this->getReadOnlyReason() !== false );
4607 * @return string|bool Reason this DB is read-only or false if it is not
4609 protected function getReadOnlyReason() {
4610 $reason = $this->getLBInfo( 'readOnlyReason' );
4612 return is_string( $reason ) ?
$reason : false;
4615 public function setTableAliases( array $aliases ) {
4616 $this->tableAliases
= $aliases;
4619 public function setIndexAliases( array $aliases ) {
4620 $this->indexAliases
= $aliases;
4624 * Get the underlying binding connection handle
4626 * Makes sure the connection resource is set (disconnects and ping() failure can unset it).
4627 * This catches broken callers than catch and ignore disconnection exceptions.
4628 * Unlike checking isOpen(), this is safe to call inside of open().
4631 * @throws DBUnexpectedError
4634 protected function getBindingHandle() {
4635 if ( !$this->conn
) {
4636 throw new DBUnexpectedError(
4638 'DB connection was already closed or the connection dropped.'
4649 public function __toString() {
4650 return (string)$this->conn
;
4654 * Make sure that copies do not share the same client binding handle
4655 * @throws DBConnectionError
4657 public function __clone() {
4658 $this->connLogger
->warning(
4659 "Cloning " . static::class . " is not recommended; forking connection:\n" .
4660 ( new RuntimeException() )->getTraceAsString()
4663 if ( $this->isOpen() ) {
4664 // Open a new connection resource without messing with the old one
4665 $this->opened
= false;
4666 $this->conn
= false;
4667 $this->trxEndCallbacks
= []; // don't copy
4668 $this->handleSessionLoss(); // no trx or locks anymore
4675 $this->tablePrefix()
4677 $this->lastPing
= microtime( true );
4682 * Called by serialize. Throw an exception when DB connection is serialized.
4683 * This causes problems on some database engines because the connection is
4684 * not restored on unserialize.
4686 public function __sleep() {
4687 throw new RuntimeException( 'Database serialization may cause problems, since ' .
4688 'the connection is not restored on wakeup.' );
4692 * Run a few simple sanity checks and close dangling connections
4694 public function __destruct() {
4695 if ( $this->trxLevel
&& $this->trxDoneWrites
) {
4696 trigger_error( "Uncommitted DB writes (transaction from {$this->trxFname})." );
4699 $danglingWriters = $this->pendingWriteAndCallbackCallers();
4700 if ( $danglingWriters ) {
4701 $fnames = implode( ', ', $danglingWriters );
4702 trigger_error( "DB transaction writes or callbacks still pending ($fnames)." );
4705 if ( $this->conn
) {
4706 // Avoid connection leaks for sanity. Normally, resources close at script completion.
4707 // The connection might already be closed in zend/hhvm by now, so suppress warnings.
4708 Wikimedia\
suppressWarnings();
4709 $this->closeConnection();
4710 Wikimedia\restoreWarnings
();
4711 $this->conn
= false;
4712 $this->opened
= false;
4718 * @deprecated since 1.28
4720 class_alias( Database
::class, 'DatabaseBase' );
4723 * @deprecated since 1.29
4725 class_alias( Database
::class, 'Database' );