3 * @defgroup Database Database
5 * This file deals with database interface functions
6 * and query specifics/optimisations.
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License along
19 * with this program; if not, write to the Free Software Foundation, Inc.,
20 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
21 * http://www.gnu.org/copyleft/gpl.html
26 namespace Wikimedia\Rdbms
;
28 use Psr\Log\LoggerAwareInterface
;
29 use Psr\Log\LoggerInterface
;
30 use Psr\Log\NullLogger
;
31 use Wikimedia\ScopedCallback
;
32 use Wikimedia\Timestamp\ConvertibleTimestamp
;
37 use InvalidArgumentException
;
38 use UnexpectedValueException
;
43 * Relational database abstraction object
48 abstract class Database
implements IDatabase
, IMaintainableDatabase
, LoggerAwareInterface
{
49 /** Number of times to re-try an operation in case of deadlock */
50 const DEADLOCK_TRIES
= 4;
51 /** Minimum time to wait before retry, in microseconds */
52 const DEADLOCK_DELAY_MIN
= 500000;
53 /** Maximum time to wait before retry */
54 const DEADLOCK_DELAY_MAX
= 1500000;
56 /** How long before it is worth doing a dummy query to test the connection */
58 const PING_QUERY
= 'SELECT 1 AS ping';
60 const TINY_WRITE_SEC
= 0.010;
61 const SLOW_WRITE_SEC
= 0.500;
62 const SMALL_WRITE_ROWS
= 100;
64 /** @var string Whether lock granularity is on the level of the entire database */
65 const ATTR_DB_LEVEL_LOCKING
= 'db-level-locking';
67 /** @var int New Database instance will not be connected yet when returned */
68 const NEW_UNCONNECTED
= 0;
69 /** @var int New Database instance will already be connected when returned */
70 const NEW_CONNECTED
= 1;
72 /** @var string SQL query */
73 protected $lastQuery = '';
74 /** @var float|bool UNIX timestamp of last write query */
75 protected $lastWriteTime = false;
76 /** @var string|bool */
77 protected $phpError = false;
78 /** @var string Server that this instance is currently connected to */
80 /** @var string User that this instance is currently connected under the name of */
82 /** @var string Password used to establish the current connection */
84 /** @var string Database that this instance is currently connected to */
86 /** @var array[] Map of (table => (dbname, schema, prefix) map) */
87 protected $tableAliases = [];
88 /** @var string[] Map of (index alias => index) */
89 protected $indexAliases = [];
90 /** @var bool Whether this PHP instance is for a CLI script */
92 /** @var string Agent name for query profiling */
94 /** @var array Parameters used by initConnection() to establish a connection */
95 protected $connectionParams = [];
96 /** @var BagOStuff APC cache */
98 /** @var LoggerInterface */
99 protected $connLogger;
100 /** @var LoggerInterface */
101 protected $queryLogger;
102 /** @var callback Error logging callback */
103 protected $errorLogger;
104 /** @var callback Deprecation logging callback */
105 protected $deprecationLogger;
107 /** @var resource|null Database connection */
108 protected $conn = null;
110 protected $opened = false;
112 /** @var array[] List of (callable, method name, atomic section id) */
113 protected $trxIdleCallbacks = [];
114 /** @var array[] List of (callable, method name, atomic section id) */
115 protected $trxPreCommitCallbacks = [];
116 /** @var array[] List of (callable, method name, atomic section id) */
117 protected $trxEndCallbacks = [];
118 /** @var callable[] Map of (name => callable) */
119 protected $trxRecurringCallbacks = [];
120 /** @var bool Whether to suppress triggering of transaction end callbacks */
121 protected $trxEndCallbacksSuppressed = false;
124 protected $tablePrefix = '';
126 protected $schema = '';
130 protected $lbInfo = [];
131 /** @var array|bool */
132 protected $schemaVars = false;
134 protected $sessionVars = [];
135 /** @var array|null */
136 protected $preparedArgs;
137 /** @var string|bool|null Stashed value of html_errors INI setting */
138 protected $htmlErrors;
140 protected $delimiter = ';';
141 /** @var DatabaseDomain */
142 protected $currentDomain;
143 /** @var integer|null Rows affected by the last query to query() or its CRUD wrappers */
144 protected $affectedRowCount;
147 * @var int Transaction status
149 protected $trxStatus = self
::STATUS_TRX_NONE
;
151 * @var Exception|null The last error that caused the status to become STATUS_TRX_ERROR
153 protected $trxStatusCause;
155 * @var array|null If wasKnownStatementRollbackError() prevented trxStatus from being set,
156 * the relevant details are stored here.
158 protected $trxStatusIgnoredCause;
160 * Either 1 if a transaction is active or 0 otherwise.
161 * The other Trx fields may not be meaningfull if this is 0.
165 protected $trxLevel = 0;
167 * Either a short hexidecimal string if a transaction is active or ""
170 * @see Database::trxLevel
172 protected $trxShortId = '';
174 * The UNIX time that the transaction started. Callers can assume that if
175 * snapshot isolation is used, then the data is *at least* up to date to that
176 * point (possibly more up-to-date since the first SELECT defines the snapshot).
179 * @see Database::trxLevel
181 private $trxTimestamp = null;
182 /** @var float Lag estimate at the time of BEGIN */
183 private $trxReplicaLag = null;
185 * Remembers the function name given for starting the most recent transaction via begin().
186 * Used to provide additional context for error reporting.
189 * @see Database::trxLevel
191 private $trxFname = null;
193 * Record if possible write queries were done in the last transaction started
196 * @see Database::trxLevel
198 private $trxDoneWrites = false;
200 * Record if the current transaction was started implicitly due to DBO_TRX being set.
203 * @see Database::trxLevel
205 private $trxAutomatic = false;
207 * Counter for atomic savepoint identifiers. Reset when a new transaction begins.
211 private $trxAtomicCounter = 0;
213 * Array of levels of atomicity within transactions
215 * @var array List of (name, unique ID, savepoint ID)
217 private $trxAtomicLevels = [];
219 * Record if the current transaction was started implicitly by Database::startAtomic
223 private $trxAutomaticAtomic = false;
225 * Track the write query callers of the current transaction
229 private $trxWriteCallers = [];
231 * @var float Seconds spent in write queries for the current transaction
233 private $trxWriteDuration = 0.0;
235 * @var int Number of write queries for the current transaction
237 private $trxWriteQueryCount = 0;
239 * @var int Number of rows affected by write queries for the current transaction
241 private $trxWriteAffectedRows = 0;
243 * @var float Like trxWriteQueryCount but excludes lock-bound, easy to replicate, queries
245 private $trxWriteAdjDuration = 0.0;
247 * @var int Number of write queries counted in trxWriteAdjDuration
249 private $trxWriteAdjQueryCount = 0;
251 * @var float RTT time estimate
253 private $rttEstimate = 0.0;
255 /** @var array Map of (name => 1) for locks obtained via lock() */
256 private $namedLocksHeld = [];
257 /** @var array Map of (table name => 1) for TEMPORARY tables */
258 protected $sessionTempTables = [];
260 /** @var IDatabase|null Lazy handle to the master DB this server replicates from */
261 private $lazyMasterHandle;
263 /** @var float UNIX timestamp */
264 protected $lastPing = 0.0;
266 /** @var int[] Prior flags member variable values */
267 private $priorFlags = [];
269 /** @var object|string Class name or object With profileIn/profileOut methods */
271 /** @var TransactionProfiler */
272 protected $trxProfiler;
275 protected $nonNativeInsertSelectBatchSize = 10000;
277 /** @var string Idiom used when a cancelable atomic section started the transaction */
278 private static $NOT_APPLICABLE = 'n/a';
279 /** @var string Prefix to the atomic section counter used to make savepoint IDs */
280 private static $SAVEPOINT_PREFIX = 'wikimedia_rdbms_atomic';
282 /** @var int Transaction is in a error state requiring a full or savepoint rollback */
283 const STATUS_TRX_ERROR
= 1;
284 /** @var int Transaction is active and in a normal state */
285 const STATUS_TRX_OK
= 2;
286 /** @var int No transaction is active */
287 const STATUS_TRX_NONE
= 3;
290 * @note: exceptions for missing libraries/drivers should be thrown in initConnection()
291 * @param array $params Parameters passed from Database::factory()
293 protected function __construct( array $params ) {
294 foreach ( [ 'host', 'user', 'password', 'dbname' ] as $name ) {
295 $this->connectionParams
[$name] = $params[$name];
298 $this->schema
= $params['schema'];
299 $this->tablePrefix
= $params['tablePrefix'];
301 $this->cliMode
= $params['cliMode'];
302 // Agent name is added to SQL queries in a comment, so make sure it can't break out
303 $this->agent
= str_replace( '/', '-', $params['agent'] );
305 $this->flags
= $params['flags'];
306 if ( $this->flags
& self
::DBO_DEFAULT
) {
307 if ( $this->cliMode
) {
308 $this->flags
&= ~self
::DBO_TRX
;
310 $this->flags |
= self
::DBO_TRX
;
313 // Disregard deprecated DBO_IGNORE flag (T189999)
314 $this->flags
&= ~self
::DBO_IGNORE
;
316 $this->sessionVars
= $params['variables'];
318 $this->srvCache
= isset( $params['srvCache'] )
319 ?
$params['srvCache']
320 : new HashBagOStuff();
322 $this->profiler
= $params['profiler'];
323 $this->trxProfiler
= $params['trxProfiler'];
324 $this->connLogger
= $params['connLogger'];
325 $this->queryLogger
= $params['queryLogger'];
326 $this->errorLogger
= $params['errorLogger'];
327 $this->deprecationLogger
= $params['deprecationLogger'];
329 if ( isset( $params['nonNativeInsertSelectBatchSize'] ) ) {
330 $this->nonNativeInsertSelectBatchSize
= $params['nonNativeInsertSelectBatchSize'];
333 // Set initial dummy domain until open() sets the final DB/prefix
334 $this->currentDomain
= DatabaseDomain
::newUnspecified();
338 * Initialize the connection to the database over the wire (or to local files)
340 * @throws LogicException
341 * @throws InvalidArgumentException
342 * @throws DBConnectionError
345 final public function initConnection() {
346 if ( $this->isOpen() ) {
347 throw new LogicException( __METHOD__
. ': already connected.' );
349 // Establish the connection
350 $this->doInitConnection();
351 // Set the domain object after open() sets the relevant fields
352 if ( $this->dbName
!= '' ) {
353 // Domains with server scope but a table prefix are not used by IDatabase classes
354 $this->currentDomain
= new DatabaseDomain( $this->dbName
, null, $this->tablePrefix
);
359 * Actually connect to the database over the wire (or to local files)
361 * @throws InvalidArgumentException
362 * @throws DBConnectionError
365 protected function doInitConnection() {
366 if ( strlen( $this->connectionParams
['user'] ) ) {
368 $this->connectionParams
['host'],
369 $this->connectionParams
['user'],
370 $this->connectionParams
['password'],
371 $this->connectionParams
['dbname']
374 throw new InvalidArgumentException( "No database user provided." );
379 * Construct a Database subclass instance given a database type and parameters
381 * This also connects to the database immediately upon object construction
383 * @param string $dbType A possible DB type (sqlite, mysql, postgres,...)
384 * @param array $p Parameter map with keys:
385 * - host : The hostname of the DB server
386 * - user : The name of the database user the client operates under
387 * - password : The password for the database user
388 * - dbname : The name of the database to use where queries do not specify one.
389 * The database must exist or an error might be thrown. Setting this to the empty string
390 * will avoid any such errors and make the handle have no implicit database scope. This is
391 * useful for queries like SHOW STATUS, CREATE DATABASE, or DROP DATABASE. Note that a
392 * "database" in Postgres is rougly equivalent to an entire MySQL server. This the domain
393 * in which user names and such are defined, e.g. users are database-specific in Postgres.
394 * - schema : The database schema to use (if supported). A "schema" in Postgres is roughly
395 * equivalent to a "database" in MySQL. Note that MySQL and SQLite do not use schemas.
396 * - tablePrefix : Optional table prefix that is implicitly added on to all table names
397 * recognized in queries. This can be used in place of schemas for handle site farms.
398 * - flags : Optional bitfield of DBO_* constants that define connection, protocol,
399 * buffering, and transaction behavior. It is STRONGLY adviced to leave the DBO_DEFAULT
400 * flag in place UNLESS this this database simply acts as a key/value store.
401 * - driver: Optional name of a specific DB client driver. For MySQL, there is only the
402 * 'mysqli' driver; the old one 'mysql' has been removed.
403 * - variables: Optional map of session variables to set after connecting. This can be
404 * used to adjust lock timeouts or encoding modes and the like.
405 * - connLogger: Optional PSR-3 logger interface instance.
406 * - queryLogger: Optional PSR-3 logger interface instance.
407 * - profiler: Optional class name or object with profileIn()/profileOut() methods.
408 * These will be called in query(), using a simplified version of the SQL that also
409 * includes the agent as a SQL comment.
410 * - trxProfiler: Optional TransactionProfiler instance.
411 * - errorLogger: Optional callback that takes an Exception and logs it.
412 * - deprecationLogger: Optional callback that takes a string and logs it.
413 * - cliMode: Whether to consider the execution context that of a CLI script.
414 * - agent: Optional name used to identify the end-user in query profiling/logging.
415 * - srvCache: Optional BagOStuff instance to an APC-style cache.
416 * - nonNativeInsertSelectBatchSize: Optional batch size for non-native INSERT SELECT emulation.
417 * @param int $connect One of the class constants (NEW_CONNECTED, NEW_UNCONNECTED) [optional]
418 * @return Database|null If the database driver or extension cannot be found
419 * @throws InvalidArgumentException If the database driver or extension cannot be found
422 final public static function factory( $dbType, $p = [], $connect = self
::NEW_CONNECTED
) {
423 $class = self
::getClass( $dbType, isset( $p['driver'] ) ?
$p['driver'] : null );
425 if ( class_exists( $class ) && is_subclass_of( $class, IDatabase
::class ) ) {
426 // Resolve some defaults for b/c
427 $p['host'] = isset( $p['host'] ) ?
$p['host'] : false;
428 $p['user'] = isset( $p['user'] ) ?
$p['user'] : false;
429 $p['password'] = isset( $p['password'] ) ?
$p['password'] : false;
430 $p['dbname'] = isset( $p['dbname'] ) ?
$p['dbname'] : false;
431 $p['flags'] = isset( $p['flags'] ) ?
$p['flags'] : 0;
432 $p['variables'] = isset( $p['variables'] ) ?
$p['variables'] : [];
433 $p['tablePrefix'] = isset( $p['tablePrefix'] ) ?
$p['tablePrefix'] : '';
434 $p['schema'] = isset( $p['schema'] ) ?
$p['schema'] : '';
435 $p['cliMode'] = isset( $p['cliMode'] )
437 : ( PHP_SAPI
=== 'cli' || PHP_SAPI
=== 'phpdbg' );
438 $p['agent'] = isset( $p['agent'] ) ?
$p['agent'] : '';
439 if ( !isset( $p['connLogger'] ) ) {
440 $p['connLogger'] = new NullLogger();
442 if ( !isset( $p['queryLogger'] ) ) {
443 $p['queryLogger'] = new NullLogger();
445 $p['profiler'] = isset( $p['profiler'] ) ?
$p['profiler'] : null;
446 if ( !isset( $p['trxProfiler'] ) ) {
447 $p['trxProfiler'] = new TransactionProfiler();
449 if ( !isset( $p['errorLogger'] ) ) {
450 $p['errorLogger'] = function ( Exception
$e ) {
451 trigger_error( get_class( $e ) . ': ' . $e->getMessage(), E_USER_WARNING
);
454 if ( !isset( $p['deprecationLogger'] ) ) {
455 $p['deprecationLogger'] = function ( $msg ) {
456 trigger_error( $msg, E_USER_DEPRECATED
);
460 /** @var Database $conn */
461 $conn = new $class( $p );
462 if ( $connect == self
::NEW_CONNECTED
) {
463 $conn->initConnection();
473 * @param string $dbType A possible DB type (sqlite, mysql, postgres,...)
474 * @param string|null $driver Optional name of a specific DB client driver
475 * @return array Map of (Database::ATTRIBUTE_* constant => value) for all such constants
476 * @throws InvalidArgumentException
479 final public static function attributesFromType( $dbType, $driver = null ) {
480 static $defaults = [ self
::ATTR_DB_LEVEL_LOCKING
=> false ];
482 $class = self
::getClass( $dbType, $driver );
484 return call_user_func( [ $class, 'getAttributes' ] ) +
$defaults;
488 * @param string $dbType A possible DB type (sqlite, mysql, postgres,...)
489 * @param string|null $driver Optional name of a specific DB client driver
490 * @return string Database subclass name to use
491 * @throws InvalidArgumentException
493 private static function getClass( $dbType, $driver = null ) {
494 // For database types with built-in support, the below maps type to IDatabase
495 // implementations. For types with multipe driver implementations (PHP extensions),
496 // an array can be used, keyed by extension name. In case of an array, the
497 // optional 'driver' parameter can be used to force a specific driver. Otherwise,
498 // we auto-detect the first available driver. For types without built-in support,
499 // an class named "Database<Type>" us used, eg. DatabaseFoo for type 'foo'.
500 static $builtinTypes = [
501 'mssql' => DatabaseMssql
::class,
502 'mysql' => [ 'mysqli' => DatabaseMysqli
::class ],
503 'sqlite' => DatabaseSqlite
::class,
504 'postgres' => DatabasePostgres
::class,
507 $dbType = strtolower( $dbType );
510 if ( isset( $builtinTypes[$dbType] ) ) {
511 $possibleDrivers = $builtinTypes[$dbType];
512 if ( is_string( $possibleDrivers ) ) {
513 $class = $possibleDrivers;
515 if ( (string)$driver !== '' ) {
516 if ( !isset( $possibleDrivers[$driver] ) ) {
517 throw new InvalidArgumentException( __METHOD__
.
518 " type '$dbType' does not support driver '{$driver}'" );
520 $class = $possibleDrivers[$driver];
523 foreach ( $possibleDrivers as $posDriver => $possibleClass ) {
524 if ( extension_loaded( $posDriver ) ) {
525 $class = $possibleClass;
532 $class = 'Database' . ucfirst( $dbType );
535 if ( $class === false ) {
536 throw new InvalidArgumentException( __METHOD__
.
537 " no viable database extension found for type '$dbType'" );
544 * @return array Map of (Database::ATTRIBUTE_* constant => value
547 protected static function getAttributes() {
552 * Set the PSR-3 logger interface to use for query logging. (The logger
553 * interfaces for connection logging and error logging can be set with the
556 * @param LoggerInterface $logger
558 public function setLogger( LoggerInterface
$logger ) {
559 $this->queryLogger
= $logger;
562 public function getServerInfo() {
563 return $this->getServerVersion();
566 public function bufferResults( $buffer = null ) {
567 $res = !$this->getFlag( self
::DBO_NOBUFFER
);
568 if ( $buffer !== null ) {
570 ?
$this->clearFlag( self
::DBO_NOBUFFER
)
571 : $this->setFlag( self
::DBO_NOBUFFER
);
577 public function trxLevel() {
578 return $this->trxLevel
;
581 public function trxTimestamp() {
582 return $this->trxLevel ?
$this->trxTimestamp
: null;
586 * @return int One of the STATUS_TRX_* class constants
589 public function trxStatus() {
590 return $this->trxStatus
;
593 public function tablePrefix( $prefix = null ) {
594 $old = $this->tablePrefix
;
595 if ( $prefix !== null ) {
596 $this->tablePrefix
= $prefix;
597 $this->currentDomain
= ( $this->dbName
!= '' )
598 ?
new DatabaseDomain( $this->dbName
, null, $this->tablePrefix
)
599 : DatabaseDomain
::newUnspecified();
605 public function dbSchema( $schema = null ) {
606 $old = $this->schema
;
607 if ( $schema !== null ) {
608 $this->schema
= $schema;
614 public function getLBInfo( $name = null ) {
615 if ( is_null( $name ) ) {
616 return $this->lbInfo
;
618 if ( array_key_exists( $name, $this->lbInfo
) ) {
619 return $this->lbInfo
[$name];
626 public function setLBInfo( $name, $value = null ) {
627 if ( is_null( $value ) ) {
628 $this->lbInfo
= $name;
630 $this->lbInfo
[$name] = $value;
634 public function setLazyMasterHandle( IDatabase
$conn ) {
635 $this->lazyMasterHandle
= $conn;
639 * @return IDatabase|null
640 * @see setLazyMasterHandle()
643 protected function getLazyMasterHandle() {
644 return $this->lazyMasterHandle
;
647 public function implicitGroupby() {
651 public function implicitOrderby() {
655 public function lastQuery() {
656 return $this->lastQuery
;
659 public function doneWrites() {
660 return (bool)$this->lastWriteTime
;
663 public function lastDoneWrites() {
664 return $this->lastWriteTime ?
: false;
667 public function writesPending() {
668 return $this->trxLevel
&& $this->trxDoneWrites
;
671 public function writesOrCallbacksPending() {
672 return $this->trxLevel
&& (
673 $this->trxDoneWrites ||
674 $this->trxIdleCallbacks ||
675 $this->trxPreCommitCallbacks ||
676 $this->trxEndCallbacks
681 * @return string|null
683 final protected function getTransactionRoundId() {
684 // If transaction round participation is enabled, see if one is active
685 if ( $this->getFlag( self
::DBO_TRX
) ) {
686 $id = $this->getLBInfo( 'trxRoundId' );
688 return is_string( $id ) ?
$id : null;
694 public function pendingWriteQueryDuration( $type = self
::ESTIMATE_TOTAL
) {
695 if ( !$this->trxLevel
) {
697 } elseif ( !$this->trxDoneWrites
) {
702 case self
::ESTIMATE_DB_APPLY
:
704 $rttAdjTotal = $this->trxWriteAdjQueryCount
* $rtt;
705 $applyTime = max( $this->trxWriteAdjDuration
- $rttAdjTotal, 0 );
706 // For omitted queries, make them count as something at least
707 $omitted = $this->trxWriteQueryCount
- $this->trxWriteAdjQueryCount
;
708 $applyTime +
= self
::TINY_WRITE_SEC
* $omitted;
711 default: // everything
712 return $this->trxWriteDuration
;
716 public function pendingWriteCallers() {
717 return $this->trxLevel ?
$this->trxWriteCallers
: [];
720 public function pendingWriteRowsAffected() {
721 return $this->trxWriteAffectedRows
;
725 * Get the list of method names that have pending write queries or callbacks
726 * for this transaction
730 protected function pendingWriteAndCallbackCallers() {
731 if ( !$this->trxLevel
) {
735 $fnames = $this->trxWriteCallers
;
737 $this->trxIdleCallbacks
,
738 $this->trxPreCommitCallbacks
,
739 $this->trxEndCallbacks
741 foreach ( $callbacks as $callback ) {
742 $fnames[] = $callback[1];
752 private function flatAtomicSectionList() {
753 return array_reduce( $this->trxAtomicLevels
, function ( $accum, $v ) {
754 return $accum === null ?
$v[0] : "$accum, " . $v[0];
758 public function isOpen() {
759 return $this->opened
;
762 public function setFlag( $flag, $remember = self
::REMEMBER_NOTHING
) {
763 if ( ( $flag & self
::DBO_IGNORE
) ) {
764 throw new UnexpectedValueException( "Modifying DBO_IGNORE is not allowed." );
767 if ( $remember === self
::REMEMBER_PRIOR
) {
768 array_push( $this->priorFlags
, $this->flags
);
770 $this->flags |
= $flag;
773 public function clearFlag( $flag, $remember = self
::REMEMBER_NOTHING
) {
774 if ( ( $flag & self
::DBO_IGNORE
) ) {
775 throw new UnexpectedValueException( "Modifying DBO_IGNORE is not allowed." );
778 if ( $remember === self
::REMEMBER_PRIOR
) {
779 array_push( $this->priorFlags
, $this->flags
);
781 $this->flags
&= ~
$flag;
784 public function restoreFlags( $state = self
::RESTORE_PRIOR
) {
785 if ( !$this->priorFlags
) {
789 if ( $state === self
::RESTORE_INITIAL
) {
790 $this->flags
= reset( $this->priorFlags
);
791 $this->priorFlags
= [];
793 $this->flags
= array_pop( $this->priorFlags
);
797 public function getFlag( $flag ) {
798 return !!( $this->flags
& $flag );
802 * @param string $name Class field name
804 * @deprecated Since 1.28
806 public function getProperty( $name ) {
810 public function getDomainID() {
811 return $this->currentDomain
->getId();
814 final public function getWikiID() {
815 return $this->getDomainID();
819 * Get information about an index into an object
820 * @param string $table Table name
821 * @param string $index Index name
822 * @param string $fname Calling function name
823 * @return mixed Database-specific index description class or false if the index does not exist
825 abstract function indexInfo( $table, $index, $fname = __METHOD__
);
828 * Wrapper for addslashes()
830 * @param string $s String to be slashed.
831 * @return string Slashed string.
833 abstract function strencode( $s );
836 * Set a custom error handler for logging errors during database connection
838 protected function installErrorHandler() {
839 $this->phpError
= false;
840 $this->htmlErrors
= ini_set( 'html_errors', '0' );
841 set_error_handler( [ $this, 'connectionErrorLogger' ] );
845 * Restore the previous error handler and return the last PHP error for this DB
847 * @return bool|string
849 protected function restoreErrorHandler() {
850 restore_error_handler();
851 if ( $this->htmlErrors
!== false ) {
852 ini_set( 'html_errors', $this->htmlErrors
);
855 return $this->getLastPHPError();
859 * @return string|bool Last PHP error for this DB (typically connection errors)
861 protected function getLastPHPError() {
862 if ( $this->phpError
) {
863 $error = preg_replace( '!\[<a.*</a>\]!', '', $this->phpError
);
864 $error = preg_replace( '!^.*?:\s?(.*)$!', '$1', $error );
873 * Error handler for logging errors during database connection
874 * This method should not be used outside of Database classes
877 * @param string $errstr
879 public function connectionErrorLogger( $errno, $errstr ) {
880 $this->phpError
= $errstr;
884 * Create a log context to pass to PSR-3 logger functions.
886 * @param array $extras Additional data to add to context
889 protected function getLogContext( array $extras = [] ) {
892 'db_server' => $this->server
,
893 'db_name' => $this->dbName
,
894 'db_user' => $this->user
,
900 final public function close() {
901 $exception = null; // error to throw after disconnecting
904 // Resolve any dangling transaction first
905 if ( $this->trxLevel
) {
906 if ( $this->trxAtomicLevels
) {
907 // Cannot let incomplete atomic sections be committed
908 $levels = $this->flatAtomicSectionList();
909 $exception = new DBUnexpectedError(
911 __METHOD__
. ": atomic sections $levels are still open."
913 } elseif ( $this->trxAutomatic
) {
914 // Only the connection manager can commit non-empty DBO_TRX transactions
915 if ( $this->writesOrCallbacksPending() ) {
916 $exception = new DBUnexpectedError(
919 ": mass commit/rollback of peer transaction required (DBO_TRX set)."
922 } elseif ( $this->trxLevel
) {
923 // Commit explicit transactions as if this was commit()
924 $this->queryLogger
->warning(
925 __METHOD__
. ": writes or callbacks still pending.",
926 [ 'trace' => ( new RuntimeException() )->getTraceAsString() ]
930 if ( $this->trxEndCallbacksSuppressed
) {
931 $exception = $exception ?
: new DBUnexpectedError(
933 __METHOD__
. ': callbacks are suppressed; cannot properly commit.'
937 // Commit or rollback the changes and run any callbacks as needed
938 if ( $this->trxStatus
=== self
::STATUS_TRX_OK
&& !$exception ) {
941 $this->trxAutomatic ? self
::FLUSHING_INTERNAL
: self
::FLUSHING_ONE
944 $this->rollback( __METHOD__
, self
::FLUSHING_INTERNAL
);
948 // Close the actual connection in the binding handle
949 $closed = $this->closeConnection();
952 $closed = true; // already closed; nothing to do
955 $this->opened
= false;
957 // Throw any unexpected errors after having disconnected
958 if ( $exception instanceof Exception
) {
962 // Sanity check that no callbacks are dangling
964 $this->trxIdleCallbacks ||
$this->trxPreCommitCallbacks ||
$this->trxEndCallbacks
966 throw new RuntimeException(
967 "Transaction callbacks are still pending:\n" .
968 implode( ', ', $this->pendingWriteAndCallbackCallers() )
976 * Make sure isOpen() returns true as a sanity check
978 * @throws DBUnexpectedError
980 protected function assertOpen() {
981 if ( !$this->isOpen() ) {
982 throw new DBUnexpectedError( $this, "DB connection was already closed." );
987 * Closes underlying database connection
989 * @return bool Whether connection was closed successfully
991 abstract protected function closeConnection();
994 * @param string $error Fallback error message, used if none is given by DB
995 * @throws DBConnectionError
997 public function reportConnectionError( $error = 'Unknown error' ) {
998 $myError = $this->lastError();
1004 throw new DBConnectionError( $this, $error );
1008 * Run a query and return a DBMS-dependent wrapper (that has all IResultWrapper methods)
1010 * This might return things, such as mysqli_result, that do not formally implement
1011 * IResultWrapper, but nonetheless implement all of its methods correctly
1013 * @param string $sql SQL query.
1014 * @return IResultWrapper|bool Iterator to feed to fetchObject/fetchRow; false on failure
1016 abstract protected function doQuery( $sql );
1019 * Determine whether a query writes to the DB.
1020 * Should return true if unsure.
1022 * @param string $sql
1025 protected function isWriteQuery( $sql ) {
1027 '/^(?:SELECT|BEGIN|ROLLBACK|COMMIT|SET|SHOW|EXPLAIN|\(SELECT)\b/i', $sql );
1031 * @param string $sql
1032 * @return string|null
1034 protected function getQueryVerb( $sql ) {
1035 return preg_match( '/^\s*([a-z]+)/i', $sql, $m ) ?
strtoupper( $m[1] ) : null;
1039 * Determine whether a SQL statement is sensitive to isolation level.
1040 * A SQL statement is considered transactable if its result could vary
1041 * depending on the transaction isolation level. Operational commands
1042 * such as 'SET' and 'SHOW' are not considered to be transactable.
1044 * @param string $sql
1047 protected function isTransactableQuery( $sql ) {
1049 $this->getQueryVerb( $sql ),
1050 [ 'BEGIN', 'COMMIT', 'ROLLBACK', 'SHOW', 'SET', 'CREATE', 'ALTER' ],
1056 * @param string $sql A SQL query
1057 * @return bool Whether $sql is SQL for TEMPORARY table operation
1059 protected function registerTempTableOperation( $sql ) {
1061 '/^CREATE\s+TEMPORARY\s+TABLE\s+(?:IF\s+NOT\s+EXISTS\s+)?[`"\']?(\w+)[`"\']?/i',
1065 $this->sessionTempTables
[$matches[1]] = 1;
1068 } elseif ( preg_match(
1069 '/^DROP\s+(?:TEMPORARY\s+)?TABLE\s+(?:IF\s+EXISTS\s+)?[`"\']?(\w+)[`"\']?/i',
1073 $isTemp = isset( $this->sessionTempTables
[$matches[1]] );
1074 unset( $this->sessionTempTables
[$matches[1]] );
1077 } elseif ( preg_match(
1078 '/^TRUNCATE\s+(?:TEMPORARY\s+)?TABLE\s+(?:IF\s+EXISTS\s+)?[`"\']?(\w+)[`"\']?/i',
1082 return isset( $this->sessionTempTables
[$matches[1]] );
1083 } elseif ( preg_match(
1084 '/^(?:INSERT\s+(?:\w+\s+)?INTO|UPDATE|DELETE\s+FROM)\s+[`"\']?(\w+)[`"\']?/i',
1088 return isset( $this->sessionTempTables
[$matches[1]] );
1094 public function query( $sql, $fname = __METHOD__
, $tempIgnore = false ) {
1095 $this->assertTransactionStatus( $sql, $fname );
1097 # Avoid fatals if close() was called
1098 $this->assertOpen();
1100 $priorWritesPending = $this->writesOrCallbacksPending();
1101 $this->lastQuery
= $sql;
1103 $isWrite = $this->isWriteQuery( $sql );
1105 $isNonTempWrite = !$this->registerTempTableOperation( $sql );
1107 $isNonTempWrite = false;
1111 if ( $this->getLBInfo( 'replica' ) === true ) {
1114 'Write operations are not allowed on replica database connections.'
1117 # In theory, non-persistent writes are allowed in read-only mode, but due to things
1118 # like https://bugs.mysql.com/bug.php?id=33669 that might not work anyway...
1119 $reason = $this->getReadOnlyReason();
1120 if ( $reason !== false ) {
1121 throw new DBReadOnlyError( $this, "Database is read-only: $reason" );
1123 # Set a flag indicating that writes have been done
1124 $this->lastWriteTime
= microtime( true );
1127 # Add trace comment to the begin of the sql string, right after the operator.
1128 # Or, for one-word queries (like "BEGIN" or COMMIT") add it to the end (T44598)
1129 $commentedSql = preg_replace( '/\s|$/', " /* $fname {$this->agent} */ ", $sql, 1 );
1131 # Start implicit transactions that wrap the request if DBO_TRX is enabled
1132 if ( !$this->trxLevel
&& $this->getFlag( self
::DBO_TRX
)
1133 && $this->isTransactableQuery( $sql )
1135 $this->begin( __METHOD__
. " ($fname)", self
::TRANSACTION_INTERNAL
);
1136 $this->trxAutomatic
= true;
1139 # Keep track of whether the transaction has write queries pending
1140 if ( $this->trxLevel
&& !$this->trxDoneWrites
&& $isWrite ) {
1141 $this->trxDoneWrites
= true;
1142 $this->trxProfiler
->transactionWritingIn(
1143 $this->server
, $this->dbName
, $this->trxShortId
);
1146 if ( $this->getFlag( self
::DBO_DEBUG
) ) {
1147 $this->queryLogger
->debug( "{$this->dbName} {$commentedSql}" );
1150 # Send the query to the server and fetch any corresponding errors
1151 $ret = $this->doProfiledQuery( $sql, $commentedSql, $isNonTempWrite, $fname );
1152 $lastError = $this->lastError();
1153 $lastErrno = $this->lastErrno();
1155 # Try reconnecting if the connection was lost
1156 if ( $ret === false && $this->wasConnectionLoss() ) {
1157 # Check if any meaningful session state was lost
1158 $recoverable = $this->canRecoverFromDisconnect( $sql, $priorWritesPending );
1159 # Update session state tracking and try to restore the connection
1160 $reconnected = $this->replaceLostConnection( __METHOD__
);
1161 # Silently resend the query to the server if it is safe and possible
1162 if ( $reconnected && $recoverable ) {
1163 $ret = $this->doProfiledQuery( $sql, $commentedSql, $isNonTempWrite, $fname );
1164 $lastError = $this->lastError();
1165 $lastErrno = $this->lastErrno();
1167 if ( $ret === false && $this->wasConnectionLoss() ) {
1168 # Query probably causes disconnects; reconnect and do not re-run it
1169 $this->replaceLostConnection( __METHOD__
);
1174 if ( $ret === false ) {
1175 if ( $this->trxLevel
) {
1176 if ( !$this->wasKnownStatementRollbackError() ) {
1177 # Either the query was aborted or all queries after BEGIN where aborted.
1178 if ( $this->explicitTrxActive() ||
$priorWritesPending ) {
1179 # In the first case, the only options going forward are (a) ROLLBACK, or
1180 # (b) ROLLBACK TO SAVEPOINT (if one was set). If the later case, the only
1181 # option is ROLLBACK, since the snapshots would have been released.
1182 $this->trxStatus
= self
::STATUS_TRX_ERROR
;
1183 $this->trxStatusCause
=
1184 $this->makeQueryException( $lastError, $lastErrno, $sql, $fname );
1185 $tempIgnore = false; // cannot recover
1187 # Nothing prior was there to lose from the transaction,
1188 # so just roll it back.
1189 $this->rollback( __METHOD__
. " ($fname)", self
::FLUSHING_INTERNAL
);
1191 $this->trxStatusIgnoredCause
= null;
1193 # We're ignoring an error that caused just the current query to be aborted.
1194 # But log the cause so we can log a deprecation notice if a
1195 # caller actually does ignore it.
1196 $this->trxStatusIgnoredCause
= [ $lastError, $lastErrno, $fname ];
1200 $this->reportQueryError( $lastError, $lastErrno, $sql, $fname, $tempIgnore );
1203 return $this->resultObject( $ret );
1207 * Wrapper for query() that also handles profiling, logging, and affected row count updates
1209 * @param string $sql Original SQL query
1210 * @param string $commentedSql SQL query with debugging/trace comment
1211 * @param bool $isWrite Whether the query is a (non-temporary) write operation
1212 * @param string $fname Name of the calling function
1213 * @return bool|ResultWrapper True for a successful write query, ResultWrapper
1214 * object for a successful read query, or false on failure
1216 private function doProfiledQuery( $sql, $commentedSql, $isWrite, $fname ) {
1217 $isMaster = !is_null( $this->getLBInfo( 'master' ) );
1218 # generalizeSQL() will probably cut down the query to reasonable
1219 # logging size most of the time. The substr is really just a sanity check.
1221 $queryProf = 'query-m: ' . substr( self
::generalizeSQL( $sql ), 0, 255 );
1223 $queryProf = 'query: ' . substr( self
::generalizeSQL( $sql ), 0, 255 );
1226 # Include query transaction state
1227 $queryProf .= $this->trxShortId ?
" [TRX#{$this->trxShortId}]" : "";
1229 $startTime = microtime( true );
1230 if ( $this->profiler
) {
1231 call_user_func( [ $this->profiler
, 'profileIn' ], $queryProf );
1233 $this->affectedRowCount
= null;
1234 $ret = $this->doQuery( $commentedSql );
1235 $this->affectedRowCount
= $this->affectedRows();
1236 if ( $this->profiler
) {
1237 call_user_func( [ $this->profiler
, 'profileOut' ], $queryProf );
1239 $queryRuntime = max( microtime( true ) - $startTime, 0.0 );
1241 unset( $queryProfSection ); // profile out (if set)
1243 if ( $ret !== false ) {
1244 $this->lastPing
= $startTime;
1245 if ( $isWrite && $this->trxLevel
) {
1246 $this->updateTrxWriteQueryTime( $sql, $queryRuntime, $this->affectedRows() );
1247 $this->trxWriteCallers
[] = $fname;
1251 if ( $sql === self
::PING_QUERY
) {
1252 $this->rttEstimate
= $queryRuntime;
1255 $this->trxProfiler
->recordQueryCompletion(
1256 $queryProf, $startTime, $isWrite, $this->affectedRows()
1258 $this->queryLogger
->debug( $sql, [
1260 'master' => $isMaster,
1261 'runtime' => $queryRuntime,
1268 * Update the estimated run-time of a query, not counting large row lock times
1270 * LoadBalancer can be set to rollback transactions that will create huge replication
1271 * lag. It bases this estimate off of pendingWriteQueryDuration(). Certain simple
1272 * queries, like inserting a row can take a long time due to row locking. This method
1273 * uses some simple heuristics to discount those cases.
1275 * @param string $sql A SQL write query
1276 * @param float $runtime Total runtime, including RTT
1277 * @param int $affected Affected row count
1279 private function updateTrxWriteQueryTime( $sql, $runtime, $affected ) {
1280 // Whether this is indicative of replica DB runtime (except for RBR or ws_repl)
1281 $indicativeOfReplicaRuntime = true;
1282 if ( $runtime > self
::SLOW_WRITE_SEC
) {
1283 $verb = $this->getQueryVerb( $sql );
1284 // insert(), upsert(), replace() are fast unless bulky in size or blocked on locks
1285 if ( $verb === 'INSERT' ) {
1286 $indicativeOfReplicaRuntime = $this->affectedRows() > self
::SMALL_WRITE_ROWS
;
1287 } elseif ( $verb === 'REPLACE' ) {
1288 $indicativeOfReplicaRuntime = $this->affectedRows() > self
::SMALL_WRITE_ROWS
/ 2;
1292 $this->trxWriteDuration +
= $runtime;
1293 $this->trxWriteQueryCount +
= 1;
1294 $this->trxWriteAffectedRows +
= $affected;
1295 if ( $indicativeOfReplicaRuntime ) {
1296 $this->trxWriteAdjDuration +
= $runtime;
1297 $this->trxWriteAdjQueryCount +
= 1;
1302 * @param string $sql
1303 * @param string $fname
1304 * @throws DBTransactionStateError
1306 private function assertTransactionStatus( $sql, $fname ) {
1307 if ( $this->getQueryVerb( $sql ) === 'ROLLBACK' ) { // transaction/savepoint
1311 if ( $this->trxStatus
< self
::STATUS_TRX_OK
) {
1312 throw new DBTransactionStateError(
1314 "Cannot execute query from $fname while transaction status is ERROR.",
1316 $this->trxStatusCause
1318 } elseif ( $this->trxStatus
=== self
::STATUS_TRX_OK
&& $this->trxStatusIgnoredCause
) {
1319 list( $iLastError, $iLastErrno, $iFname ) = $this->trxStatusIgnoredCause
;
1320 call_user_func( $this->deprecationLogger
,
1321 "Caller from $fname ignored an error originally raised from $iFname: " .
1322 "[$iLastErrno] $iLastError"
1324 $this->trxStatusIgnoredCause
= null;
1329 * Determine whether or not it is safe to retry queries after a database
1330 * connection is lost
1332 * @param string $sql SQL query
1333 * @param bool $priorWritesPending Whether there is a transaction open with
1334 * possible write queries or transaction pre-commit/idle callbacks
1335 * waiting on it to finish.
1336 * @return bool True if it is safe to retry the query, false otherwise
1338 private function canRecoverFromDisconnect( $sql, $priorWritesPending ) {
1339 # Transaction dropped; this can mean lost writes, or REPEATABLE-READ snapshots.
1340 # Dropped connections also mean that named locks are automatically released.
1341 # Only allow error suppression in autocommit mode or when the lost transaction
1342 # didn't matter anyway (aside from DBO_TRX snapshot loss).
1343 if ( $this->namedLocksHeld
) {
1344 return false; // possible critical section violation
1345 } elseif ( $this->sessionTempTables
) {
1346 return false; // tables might be queried latter
1347 } elseif ( $sql === 'COMMIT' ) {
1348 return !$priorWritesPending; // nothing written anyway? (T127428)
1349 } elseif ( $sql === 'ROLLBACK' ) {
1350 return true; // transaction lost...which is also what was requested :)
1351 } elseif ( $this->explicitTrxActive() ) {
1352 return false; // don't drop atomocity and explicit snapshots
1353 } elseif ( $priorWritesPending ) {
1354 return false; // prior writes lost from implicit transaction
1361 * Clean things up after session (and thus transaction) loss
1363 private function handleSessionLoss() {
1364 // Clean up tracking of session-level things...
1365 // https://dev.mysql.com/doc/refman/5.7/en/implicit-commit.html
1366 // https://www.postgresql.org/docs/9.2/static/sql-createtable.html (ignoring ON COMMIT)
1367 $this->sessionTempTables
= [];
1368 // https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_get-lock
1369 // https://www.postgresql.org/docs/9.4/static/functions-admin.html#FUNCTIONS-ADVISORY-LOCKS
1370 $this->namedLocksHeld
= [];
1371 // Session loss implies transaction loss
1372 $this->handleTransactionLoss();
1376 * Clean things up after transaction loss
1378 private function handleTransactionLoss() {
1379 $this->trxLevel
= 0;
1380 $this->trxAtomicCounter
= 0;
1381 $this->trxIdleCallbacks
= []; // T67263; transaction already lost
1382 $this->trxPreCommitCallbacks
= []; // T67263; transaction already lost
1384 // Handle callbacks in trxEndCallbacks, e.g. onTransactionResolution().
1385 // If callback suppression is set then the array will remain unhandled.
1386 $this->runOnTransactionIdleCallbacks( self
::TRIGGER_ROLLBACK
);
1387 } catch ( Exception
$ex ) {
1388 // Already logged; move on...
1391 // Handle callbacks in trxRecurringCallbacks, e.g. setTransactionListener()
1392 $this->runTransactionListenerCallbacks( self
::TRIGGER_ROLLBACK
);
1393 } catch ( Exception
$ex ) {
1394 // Already logged; move on...
1399 * Checks whether the cause of the error is detected to be a timeout.
1401 * It returns false by default, and not all engines support detecting this yet.
1402 * If this returns false, it will be treated as a generic query error.
1404 * @param string $error Error text
1405 * @param int $errno Error number
1408 protected function wasQueryTimeout( $error, $errno ) {
1413 * Report a query error. Log the error, and if neither the object ignore
1414 * flag nor the $tempIgnore flag is set, throw a DBQueryError.
1416 * @param string $error
1418 * @param string $sql
1419 * @param string $fname
1420 * @param bool $tempIgnore
1421 * @throws DBQueryError
1423 public function reportQueryError( $error, $errno, $sql, $fname, $tempIgnore = false ) {
1424 if ( $tempIgnore ) {
1425 $this->queryLogger
->debug( "SQL ERROR (ignored): $error\n" );
1427 $exception = $this->makeQueryException( $error, $errno, $sql, $fname );
1434 * @param string $error
1435 * @param string|int $errno
1436 * @param string $sql
1437 * @param string $fname
1440 private function makeQueryException( $error, $errno, $sql, $fname ) {
1441 $sql1line = mb_substr( str_replace( "\n", "\\n", $sql ), 0, 5 * 1024 );
1442 $this->queryLogger
->error(
1443 "{fname}\t{db_server}\t{errno}\t{error}\t{sql1line}",
1444 $this->getLogContext( [
1445 'method' => __METHOD__
,
1448 'sql1line' => $sql1line,
1452 $this->queryLogger
->debug( "SQL ERROR: " . $error . "\n" );
1453 $wasQueryTimeout = $this->wasQueryTimeout( $error, $errno );
1454 if ( $wasQueryTimeout ) {
1455 $e = new DBQueryTimeoutError( $this, $error, $errno, $sql, $fname );
1457 $e = new DBQueryError( $this, $error, $errno, $sql, $fname );
1463 public function freeResult( $res ) {
1466 public function selectField(
1467 $table, $var, $cond = '', $fname = __METHOD__
, $options = [], $join_conds = []
1469 if ( $var === '*' ) { // sanity
1470 throw new DBUnexpectedError( $this, "Cannot use a * field: got '$var'" );
1473 if ( !is_array( $options ) ) {
1474 $options = [ $options ];
1477 $options['LIMIT'] = 1;
1479 $res = $this->select( $table, $var, $cond, $fname, $options, $join_conds );
1480 if ( $res === false ||
!$this->numRows( $res ) ) {
1484 $row = $this->fetchRow( $res );
1486 if ( $row !== false ) {
1487 return reset( $row );
1493 public function selectFieldValues(
1494 $table, $var, $cond = '', $fname = __METHOD__
, $options = [], $join_conds = []
1496 if ( $var === '*' ) { // sanity
1497 throw new DBUnexpectedError( $this, "Cannot use a * field" );
1498 } elseif ( !is_string( $var ) ) { // sanity
1499 throw new DBUnexpectedError( $this, "Cannot use an array of fields" );
1502 if ( !is_array( $options ) ) {
1503 $options = [ $options ];
1506 $res = $this->select( $table, $var, $cond, $fname, $options, $join_conds );
1507 if ( $res === false ) {
1512 foreach ( $res as $row ) {
1513 $values[] = $row->$var;
1520 * Returns an optional USE INDEX clause to go after the table, and a
1521 * string to go at the end of the query.
1523 * @param array $options Associative array of options to be turned into
1524 * an SQL query, valid keys are listed in the function.
1526 * @see Database::select()
1528 protected function makeSelectOptions( $options ) {
1529 $preLimitTail = $postLimitTail = '';
1534 foreach ( $options as $key => $option ) {
1535 if ( is_numeric( $key ) ) {
1536 $noKeyOptions[$option] = true;
1540 $preLimitTail .= $this->makeGroupByWithHaving( $options );
1542 $preLimitTail .= $this->makeOrderBy( $options );
1544 if ( isset( $noKeyOptions['FOR UPDATE'] ) ) {
1545 $postLimitTail .= ' FOR UPDATE';
1548 if ( isset( $noKeyOptions['LOCK IN SHARE MODE'] ) ) {
1549 $postLimitTail .= ' LOCK IN SHARE MODE';
1552 if ( isset( $noKeyOptions['DISTINCT'] ) ||
isset( $noKeyOptions['DISTINCTROW'] ) ) {
1553 $startOpts .= 'DISTINCT';
1556 # Various MySQL extensions
1557 if ( isset( $noKeyOptions['STRAIGHT_JOIN'] ) ) {
1558 $startOpts .= ' /*! STRAIGHT_JOIN */';
1561 if ( isset( $noKeyOptions['HIGH_PRIORITY'] ) ) {
1562 $startOpts .= ' HIGH_PRIORITY';
1565 if ( isset( $noKeyOptions['SQL_BIG_RESULT'] ) ) {
1566 $startOpts .= ' SQL_BIG_RESULT';
1569 if ( isset( $noKeyOptions['SQL_BUFFER_RESULT'] ) ) {
1570 $startOpts .= ' SQL_BUFFER_RESULT';
1573 if ( isset( $noKeyOptions['SQL_SMALL_RESULT'] ) ) {
1574 $startOpts .= ' SQL_SMALL_RESULT';
1577 if ( isset( $noKeyOptions['SQL_CALC_FOUND_ROWS'] ) ) {
1578 $startOpts .= ' SQL_CALC_FOUND_ROWS';
1581 if ( isset( $noKeyOptions['SQL_CACHE'] ) ) {
1582 $startOpts .= ' SQL_CACHE';
1585 if ( isset( $noKeyOptions['SQL_NO_CACHE'] ) ) {
1586 $startOpts .= ' SQL_NO_CACHE';
1589 if ( isset( $options['USE INDEX'] ) && is_string( $options['USE INDEX'] ) ) {
1590 $useIndex = $this->useIndexClause( $options['USE INDEX'] );
1594 if ( isset( $options['IGNORE INDEX'] ) && is_string( $options['IGNORE INDEX'] ) ) {
1595 $ignoreIndex = $this->ignoreIndexClause( $options['IGNORE INDEX'] );
1600 return [ $startOpts, $useIndex, $preLimitTail, $postLimitTail, $ignoreIndex ];
1604 * Returns an optional GROUP BY with an optional HAVING
1606 * @param array $options Associative array of options
1608 * @see Database::select()
1611 protected function makeGroupByWithHaving( $options ) {
1613 if ( isset( $options['GROUP BY'] ) ) {
1614 $gb = is_array( $options['GROUP BY'] )
1615 ?
implode( ',', $options['GROUP BY'] )
1616 : $options['GROUP BY'];
1617 $sql .= ' GROUP BY ' . $gb;
1619 if ( isset( $options['HAVING'] ) ) {
1620 $having = is_array( $options['HAVING'] )
1621 ?
$this->makeList( $options['HAVING'], self
::LIST_AND
)
1622 : $options['HAVING'];
1623 $sql .= ' HAVING ' . $having;
1630 * Returns an optional ORDER BY
1632 * @param array $options Associative array of options
1634 * @see Database::select()
1637 protected function makeOrderBy( $options ) {
1638 if ( isset( $options['ORDER BY'] ) ) {
1639 $ob = is_array( $options['ORDER BY'] )
1640 ?
implode( ',', $options['ORDER BY'] )
1641 : $options['ORDER BY'];
1643 return ' ORDER BY ' . $ob;
1649 public function select( $table, $vars, $conds = '', $fname = __METHOD__
,
1650 $options = [], $join_conds = [] ) {
1651 $sql = $this->selectSQLText( $table, $vars, $conds, $fname, $options, $join_conds );
1653 return $this->query( $sql, $fname );
1656 public function selectSQLText( $table, $vars, $conds = '', $fname = __METHOD__
,
1657 $options = [], $join_conds = []
1659 if ( is_array( $vars ) ) {
1660 $vars = implode( ',', $this->fieldNamesWithAlias( $vars ) );
1663 $options = (array)$options;
1664 $useIndexes = ( isset( $options['USE INDEX'] ) && is_array( $options['USE INDEX'] ) )
1665 ?
$options['USE INDEX']
1668 isset( $options['IGNORE INDEX'] ) &&
1669 is_array( $options['IGNORE INDEX'] )
1671 ?
$options['IGNORE INDEX']
1674 if ( is_array( $table ) ) {
1676 $this->tableNamesWithIndexClauseOrJOIN(
1677 $table, $useIndexes, $ignoreIndexes, $join_conds );
1678 } elseif ( $table != '' ) {
1680 $this->tableNamesWithIndexClauseOrJOIN(
1681 [ $table ], $useIndexes, $ignoreIndexes, [] );
1686 list( $startOpts, $useIndex, $preLimitTail, $postLimitTail, $ignoreIndex ) =
1687 $this->makeSelectOptions( $options );
1689 if ( is_array( $conds ) ) {
1690 $conds = $this->makeList( $conds, self
::LIST_AND
);
1693 if ( $conds === null ||
$conds === false ) {
1694 $this->queryLogger
->warning(
1698 . ' with incorrect parameters: $conds must be a string or an array'
1703 if ( $conds === '' ) {
1704 $sql = "SELECT $startOpts $vars $from $useIndex $ignoreIndex $preLimitTail";
1705 } elseif ( is_string( $conds ) ) {
1706 $sql = "SELECT $startOpts $vars $from $useIndex $ignoreIndex " .
1707 "WHERE $conds $preLimitTail";
1709 throw new DBUnexpectedError( $this, __METHOD__
. ' called with incorrect parameters' );
1712 if ( isset( $options['LIMIT'] ) ) {
1713 $sql = $this->limitResult( $sql, $options['LIMIT'],
1714 isset( $options['OFFSET'] ) ?
$options['OFFSET'] : false );
1716 $sql = "$sql $postLimitTail";
1718 if ( isset( $options['EXPLAIN'] ) ) {
1719 $sql = 'EXPLAIN ' . $sql;
1725 public function selectRow( $table, $vars, $conds, $fname = __METHOD__
,
1726 $options = [], $join_conds = []
1728 $options = (array)$options;
1729 $options['LIMIT'] = 1;
1730 $res = $this->select( $table, $vars, $conds, $fname, $options, $join_conds );
1732 if ( $res === false ) {
1736 if ( !$this->numRows( $res ) ) {
1740 $obj = $this->fetchObject( $res );
1745 public function estimateRowCount(
1746 $table, $var = '*', $conds = '', $fname = __METHOD__
, $options = [], $join_conds = []
1748 $conds = $this->normalizeConditions( $conds, $fname );
1749 $column = $this->extractSingleFieldFromList( $var );
1750 if ( is_string( $column ) && !in_array( $column, [ '*', '1' ] ) ) {
1751 $conds[] = "$column IS NOT NULL";
1754 $res = $this->select(
1755 $table, [ 'rowcount' => 'COUNT(*)' ], $conds, $fname, $options, $join_conds
1757 $row = $res ?
$this->fetchRow( $res ) : [];
1759 return isset( $row['rowcount'] ) ?
(int)$row['rowcount'] : 0;
1762 public function selectRowCount(
1763 $tables, $var = '*', $conds = '', $fname = __METHOD__
, $options = [], $join_conds = []
1765 $conds = $this->normalizeConditions( $conds, $fname );
1766 $column = $this->extractSingleFieldFromList( $var );
1767 if ( is_string( $column ) && !in_array( $column, [ '*', '1' ] ) ) {
1768 $conds[] = "$column IS NOT NULL";
1771 $res = $this->select(
1773 'tmp_count' => $this->buildSelectSubquery(
1782 [ 'rowcount' => 'COUNT(*)' ],
1786 $row = $res ?
$this->fetchRow( $res ) : [];
1788 return isset( $row['rowcount'] ) ?
(int)$row['rowcount'] : 0;
1792 * @param array|string $conds
1793 * @param string $fname
1796 final protected function normalizeConditions( $conds, $fname ) {
1797 if ( $conds === null ||
$conds === false ) {
1798 $this->queryLogger
->warning(
1802 . ' with incorrect parameters: $conds must be a string or an array'
1807 if ( !is_array( $conds ) ) {
1808 $conds = ( $conds === '' ) ?
[] : [ $conds ];
1815 * @param array|string $var Field parameter in the style of select()
1816 * @return string|null Column name or null; ignores aliases
1817 * @throws DBUnexpectedError Errors out if multiple columns are given
1819 final protected function extractSingleFieldFromList( $var ) {
1820 if ( is_array( $var ) ) {
1823 } elseif ( count( $var ) == 1 ) {
1824 $column = isset( $var[0] ) ?
$var[0] : reset( $var );
1826 throw new DBUnexpectedError( $this, __METHOD__
. ': got multiple columns.' );
1836 * Removes most variables from an SQL query and replaces them with X or N for numbers.
1837 * It's only slightly flawed. Don't use for anything important.
1839 * @param string $sql A SQL Query
1843 protected static function generalizeSQL( $sql ) {
1844 # This does the same as the regexp below would do, but in such a way
1845 # as to avoid crashing php on some large strings.
1846 # $sql = preg_replace( "/'([^\\\\']|\\\\.)*'|\"([^\\\\\"]|\\\\.)*\"/", "'X'", $sql );
1848 $sql = str_replace( "\\\\", '', $sql );
1849 $sql = str_replace( "\\'", '', $sql );
1850 $sql = str_replace( "\\\"", '', $sql );
1851 $sql = preg_replace( "/'.*'/s", "'X'", $sql );
1852 $sql = preg_replace( '/".*"/s', "'X'", $sql );
1854 # All newlines, tabs, etc replaced by single space
1855 $sql = preg_replace( '/\s+/', ' ', $sql );
1858 # except the ones surrounded by characters, e.g. l10n
1859 $sql = preg_replace( '/-?\d+(,-?\d+)+/s', 'N,...,N', $sql );
1860 $sql = preg_replace( '/(?<![a-zA-Z])-?\d+(?![a-zA-Z])/s', 'N', $sql );
1865 public function fieldExists( $table, $field, $fname = __METHOD__
) {
1866 $info = $this->fieldInfo( $table, $field );
1871 public function indexExists( $table, $index, $fname = __METHOD__
) {
1872 if ( !$this->tableExists( $table ) ) {
1876 $info = $this->indexInfo( $table, $index, $fname );
1877 if ( is_null( $info ) ) {
1880 return $info !== false;
1884 public function tableExists( $table, $fname = __METHOD__
) {
1885 $tableRaw = $this->tableName( $table, 'raw' );
1886 if ( isset( $this->sessionTempTables
[$tableRaw] ) ) {
1887 return true; // already known to exist
1890 $table = $this->tableName( $table );
1891 $ignoreErrors = true;
1892 $res = $this->query( "SELECT 1 FROM $table LIMIT 1", $fname, $ignoreErrors );
1897 public function indexUnique( $table, $index ) {
1898 $indexInfo = $this->indexInfo( $table, $index );
1900 if ( !$indexInfo ) {
1904 return !$indexInfo[0]->Non_unique
;
1908 * Helper for Database::insert().
1910 * @param array $options
1913 protected function makeInsertOptions( $options ) {
1914 return implode( ' ', $options );
1917 public function insert( $table, $a, $fname = __METHOD__
, $options = [] ) {
1918 # No rows to insert, easy just return now
1919 if ( !count( $a ) ) {
1923 $table = $this->tableName( $table );
1925 if ( !is_array( $options ) ) {
1926 $options = [ $options ];
1930 if ( isset( $options['fileHandle'] ) ) {
1931 $fh = $options['fileHandle'];
1933 $options = $this->makeInsertOptions( $options );
1935 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
1937 $keys = array_keys( $a[0] );
1940 $keys = array_keys( $a );
1943 $sql = 'INSERT ' . $options .
1944 " INTO $table (" . implode( ',', $keys ) . ') VALUES ';
1948 foreach ( $a as $row ) {
1954 $sql .= '(' . $this->makeList( $row ) . ')';
1957 $sql .= '(' . $this->makeList( $a ) . ')';
1960 if ( $fh !== null && false === fwrite( $fh, $sql ) ) {
1962 } elseif ( $fh !== null ) {
1966 return (bool)$this->query( $sql, $fname );
1970 * Make UPDATE options array for Database::makeUpdateOptions
1972 * @param array $options
1975 protected function makeUpdateOptionsArray( $options ) {
1976 if ( !is_array( $options ) ) {
1977 $options = [ $options ];
1982 if ( in_array( 'IGNORE', $options ) ) {
1990 * Make UPDATE options for the Database::update function
1992 * @param array $options The options passed to Database::update
1995 protected function makeUpdateOptions( $options ) {
1996 $opts = $this->makeUpdateOptionsArray( $options );
1998 return implode( ' ', $opts );
2001 public function update( $table, $values, $conds, $fname = __METHOD__
, $options = [] ) {
2002 $table = $this->tableName( $table );
2003 $opts = $this->makeUpdateOptions( $options );
2004 $sql = "UPDATE $opts $table SET " . $this->makeList( $values, self
::LIST_SET
);
2006 if ( $conds !== [] && $conds !== '*' ) {
2007 $sql .= " WHERE " . $this->makeList( $conds, self
::LIST_AND
);
2010 return (bool)$this->query( $sql, $fname );
2013 public function makeList( $a, $mode = self
::LIST_COMMA
) {
2014 if ( !is_array( $a ) ) {
2015 throw new DBUnexpectedError( $this, __METHOD__
. ' called with incorrect parameters' );
2021 foreach ( $a as $field => $value ) {
2023 if ( $mode == self
::LIST_AND
) {
2025 } elseif ( $mode == self
::LIST_OR
) {
2034 if ( ( $mode == self
::LIST_AND ||
$mode == self
::LIST_OR
) && is_numeric( $field ) ) {
2035 $list .= "($value)";
2036 } elseif ( $mode == self
::LIST_SET
&& is_numeric( $field ) ) {
2039 ( $mode == self
::LIST_AND ||
$mode == self
::LIST_OR
) && is_array( $value )
2041 // Remove null from array to be handled separately if found
2042 $includeNull = false;
2043 foreach ( array_keys( $value, null, true ) as $nullKey ) {
2044 $includeNull = true;
2045 unset( $value[$nullKey] );
2047 if ( count( $value ) == 0 && !$includeNull ) {
2048 throw new InvalidArgumentException(
2049 __METHOD__
. ": empty input for field $field" );
2050 } elseif ( count( $value ) == 0 ) {
2051 // only check if $field is null
2052 $list .= "$field IS NULL";
2054 // IN clause contains at least one valid element
2055 if ( $includeNull ) {
2056 // Group subconditions to ensure correct precedence
2059 if ( count( $value ) == 1 ) {
2060 // Special-case single values, as IN isn't terribly efficient
2061 // Don't necessarily assume the single key is 0; we don't
2062 // enforce linear numeric ordering on other arrays here.
2063 $value = array_values( $value )[0];
2064 $list .= $field . " = " . $this->addQuotes( $value );
2066 $list .= $field . " IN (" . $this->makeList( $value ) . ") ";
2068 // if null present in array, append IS NULL
2069 if ( $includeNull ) {
2070 $list .= " OR $field IS NULL)";
2073 } elseif ( $value === null ) {
2074 if ( $mode == self
::LIST_AND ||
$mode == self
::LIST_OR
) {
2075 $list .= "$field IS ";
2076 } elseif ( $mode == self
::LIST_SET
) {
2077 $list .= "$field = ";
2082 $mode == self
::LIST_AND ||
$mode == self
::LIST_OR ||
$mode == self
::LIST_SET
2084 $list .= "$field = ";
2086 $list .= $mode == self
::LIST_NAMES ?
$value : $this->addQuotes( $value );
2093 public function makeWhereFrom2d( $data, $baseKey, $subKey ) {
2096 foreach ( $data as $base => $sub ) {
2097 if ( count( $sub ) ) {
2098 $conds[] = $this->makeList(
2099 [ $baseKey => $base, $subKey => array_keys( $sub ) ],
2105 return $this->makeList( $conds, self
::LIST_OR
);
2107 // Nothing to search for...
2112 public function aggregateValue( $valuedata, $valuename = 'value' ) {
2116 public function bitNot( $field ) {
2120 public function bitAnd( $fieldLeft, $fieldRight ) {
2121 return "($fieldLeft & $fieldRight)";
2124 public function bitOr( $fieldLeft, $fieldRight ) {
2125 return "($fieldLeft | $fieldRight)";
2128 public function buildConcat( $stringList ) {
2129 return 'CONCAT(' . implode( ',', $stringList ) . ')';
2132 public function buildGroupConcatField(
2133 $delim, $table, $field, $conds = '', $join_conds = []
2135 $fld = "GROUP_CONCAT($field SEPARATOR " . $this->addQuotes( $delim ) . ')';
2137 return '(' . $this->selectSQLText( $table, $fld, $conds, null, [], $join_conds ) . ')';
2140 public function buildSubstring( $input, $startPosition, $length = null ) {
2141 $this->assertBuildSubstringParams( $startPosition, $length );
2142 $functionBody = "$input FROM $startPosition";
2143 if ( $length !== null ) {
2144 $functionBody .= " FOR $length";
2146 return 'SUBSTRING(' . $functionBody . ')';
2150 * Check type and bounds for parameters to self::buildSubstring()
2152 * All supported databases have substring functions that behave the same for
2153 * positive $startPosition and non-negative $length, but behaviors differ when
2154 * given 0 or negative $startPosition or negative $length. The simplest
2155 * solution to that is to just forbid those values.
2157 * @param int $startPosition
2158 * @param int|null $length
2161 protected function assertBuildSubstringParams( $startPosition, $length ) {
2162 if ( !is_int( $startPosition ) ||
$startPosition <= 0 ) {
2163 throw new InvalidArgumentException(
2164 '$startPosition must be a positive integer'
2167 if ( !( is_int( $length ) && $length >= 0 ||
$length === null ) ) {
2168 throw new InvalidArgumentException(
2169 '$length must be null or an integer greater than or equal to 0'
2174 public function buildStringCast( $field ) {
2178 public function buildIntegerCast( $field ) {
2179 return 'CAST( ' . $field . ' AS INTEGER )';
2182 public function buildSelectSubquery(
2183 $table, $vars, $conds = '', $fname = __METHOD__
,
2184 $options = [], $join_conds = []
2186 return new Subquery(
2187 $this->selectSQLText( $table, $vars, $conds, $fname, $options, $join_conds )
2191 public function databasesAreIndependent() {
2195 public function selectDB( $db ) {
2196 # Stub. Shouldn't cause serious problems if it's not overridden, but
2197 # if your database engine supports a concept similar to MySQL's
2198 # databases you may as well.
2199 $this->dbName
= $db;
2204 public function getDBname() {
2205 return $this->dbName
;
2208 public function getServer() {
2209 return $this->server
;
2212 public function tableName( $name, $format = 'quoted' ) {
2213 if ( $name instanceof Subquery
) {
2214 throw new DBUnexpectedError(
2216 __METHOD__
. ': got Subquery instance when expecting a string.'
2220 # Skip the entire process when we have a string quoted on both ends.
2221 # Note that we check the end so that we will still quote any use of
2222 # use of `database`.table. But won't break things if someone wants
2223 # to query a database table with a dot in the name.
2224 if ( $this->isQuotedIdentifier( $name ) ) {
2228 # Lets test for any bits of text that should never show up in a table
2229 # name. Basically anything like JOIN or ON which are actually part of
2230 # SQL queries, but may end up inside of the table value to combine
2231 # sql. Such as how the API is doing.
2232 # Note that we use a whitespace test rather than a \b test to avoid
2233 # any remote case where a word like on may be inside of a table name
2234 # surrounded by symbols which may be considered word breaks.
2235 if ( preg_match( '/(^|\s)(DISTINCT|JOIN|ON|AS)(\s|$)/i', $name ) !== 0 ) {
2236 $this->queryLogger
->warning(
2237 __METHOD__
. ": use of subqueries is not supported this way.",
2238 [ 'trace' => ( new RuntimeException() )->getTraceAsString() ]
2244 # Split database and table into proper variables.
2245 list( $database, $schema, $prefix, $table ) = $this->qualifiedTableComponents( $name );
2247 # Quote $table and apply the prefix if not quoted.
2248 # $tableName might be empty if this is called from Database::replaceVars()
2249 $tableName = "{$prefix}{$table}";
2250 if ( $format === 'quoted'
2251 && !$this->isQuotedIdentifier( $tableName )
2252 && $tableName !== ''
2254 $tableName = $this->addIdentifierQuotes( $tableName );
2257 # Quote $schema and $database and merge them with the table name if needed
2258 $tableName = $this->prependDatabaseOrSchema( $schema, $tableName, $format );
2259 $tableName = $this->prependDatabaseOrSchema( $database, $tableName, $format );
2265 * Get the table components needed for a query given the currently selected database
2267 * @param string $name Table name in the form of db.schema.table, db.table, or table
2268 * @return array (DB name or "" for default, schema name, table prefix, table name)
2270 protected function qualifiedTableComponents( $name ) {
2271 # We reverse the explode so that database.table and table both output the correct table.
2272 $dbDetails = explode( '.', $name, 3 );
2273 if ( count( $dbDetails ) == 3 ) {
2274 list( $database, $schema, $table ) = $dbDetails;
2275 # We don't want any prefix added in this case
2277 } elseif ( count( $dbDetails ) == 2 ) {
2278 list( $database, $table ) = $dbDetails;
2279 # We don't want any prefix added in this case
2281 # In dbs that support it, $database may actually be the schema
2282 # but that doesn't affect any of the functionality here
2285 list( $table ) = $dbDetails;
2286 if ( isset( $this->tableAliases
[$table] ) ) {
2287 $database = $this->tableAliases
[$table]['dbname'];
2288 $schema = is_string( $this->tableAliases
[$table]['schema'] )
2289 ?
$this->tableAliases
[$table]['schema']
2291 $prefix = is_string( $this->tableAliases
[$table]['prefix'] )
2292 ?
$this->tableAliases
[$table]['prefix']
2293 : $this->tablePrefix
;
2296 $schema = $this->schema
; # Default schema
2297 $prefix = $this->tablePrefix
; # Default prefix
2301 return [ $database, $schema, $prefix, $table ];
2305 * @param string|null $namespace Database or schema
2306 * @param string $relation Name of table, view, sequence, etc...
2307 * @param string $format One of (raw, quoted)
2308 * @return string Relation name with quoted and merged $namespace as needed
2310 private function prependDatabaseOrSchema( $namespace, $relation, $format ) {
2311 if ( strlen( $namespace ) ) {
2312 if ( $format === 'quoted' && !$this->isQuotedIdentifier( $namespace ) ) {
2313 $namespace = $this->addIdentifierQuotes( $namespace );
2315 $relation = $namespace . '.' . $relation;
2321 public function tableNames() {
2322 $inArray = func_get_args();
2325 foreach ( $inArray as $name ) {
2326 $retVal[$name] = $this->tableName( $name );
2332 public function tableNamesN() {
2333 $inArray = func_get_args();
2336 foreach ( $inArray as $name ) {
2337 $retVal[] = $this->tableName( $name );
2344 * Get an aliased table name
2346 * This returns strings like "tableName AS newTableName" for aliased tables
2347 * and "(SELECT * from tableA) newTablename" for subqueries (e.g. derived tables)
2349 * @see Database::tableName()
2350 * @param string|Subquery $table Table name or object with a 'sql' field
2351 * @param string|bool $alias Table alias (optional)
2352 * @return string SQL name for aliased table. Will not alias a table to its own name
2354 protected function tableNameWithAlias( $table, $alias = false ) {
2355 if ( is_string( $table ) ) {
2356 $quotedTable = $this->tableName( $table );
2357 } elseif ( $table instanceof Subquery
) {
2358 $quotedTable = (string)$table;
2360 throw new InvalidArgumentException( "Table must be a string or Subquery." );
2363 if ( !strlen( $alias ) ||
$alias === $table ) {
2364 if ( $table instanceof Subquery
) {
2365 throw new InvalidArgumentException( "Subquery table missing alias." );
2368 return $quotedTable;
2370 return $quotedTable . ' ' . $this->addIdentifierQuotes( $alias );
2375 * Gets an array of aliased table names
2377 * @param array $tables [ [alias] => table ]
2378 * @return string[] See tableNameWithAlias()
2380 protected function tableNamesWithAlias( $tables ) {
2382 foreach ( $tables as $alias => $table ) {
2383 if ( is_numeric( $alias ) ) {
2386 $retval[] = $this->tableNameWithAlias( $table, $alias );
2393 * Get an aliased field name
2394 * e.g. fieldName AS newFieldName
2396 * @param string $name Field name
2397 * @param string|bool $alias Alias (optional)
2398 * @return string SQL name for aliased field. Will not alias a field to its own name
2400 protected function fieldNameWithAlias( $name, $alias = false ) {
2401 if ( !$alias ||
(string)$alias === (string)$name ) {
2404 return $name . ' AS ' . $this->addIdentifierQuotes( $alias ); // PostgreSQL needs AS
2409 * Gets an array of aliased field names
2411 * @param array $fields [ [alias] => field ]
2412 * @return string[] See fieldNameWithAlias()
2414 protected function fieldNamesWithAlias( $fields ) {
2416 foreach ( $fields as $alias => $field ) {
2417 if ( is_numeric( $alias ) ) {
2420 $retval[] = $this->fieldNameWithAlias( $field, $alias );
2427 * Get the aliased table name clause for a FROM clause
2428 * which might have a JOIN and/or USE INDEX or IGNORE INDEX clause
2430 * @param array $tables ( [alias] => table )
2431 * @param array $use_index Same as for select()
2432 * @param array $ignore_index Same as for select()
2433 * @param array $join_conds Same as for select()
2436 protected function tableNamesWithIndexClauseOrJOIN(
2437 $tables, $use_index = [], $ignore_index = [], $join_conds = []
2441 $use_index = (array)$use_index;
2442 $ignore_index = (array)$ignore_index;
2443 $join_conds = (array)$join_conds;
2445 foreach ( $tables as $alias => $table ) {
2446 if ( !is_string( $alias ) ) {
2447 // No alias? Set it equal to the table name
2451 if ( is_array( $table ) ) {
2452 // A parenthesized group
2453 if ( count( $table ) > 1 ) {
2454 $joinedTable = '(' .
2455 $this->tableNamesWithIndexClauseOrJOIN(
2456 $table, $use_index, $ignore_index, $join_conds ) . ')';
2459 $innerTable = reset( $table );
2460 $innerAlias = key( $table );
2461 $joinedTable = $this->tableNameWithAlias(
2463 is_string( $innerAlias ) ?
$innerAlias : $innerTable
2467 $joinedTable = $this->tableNameWithAlias( $table, $alias );
2470 // Is there a JOIN clause for this table?
2471 if ( isset( $join_conds[$alias] ) ) {
2472 list( $joinType, $conds ) = $join_conds[$alias];
2473 $tableClause = $joinType;
2474 $tableClause .= ' ' . $joinedTable;
2475 if ( isset( $use_index[$alias] ) ) { // has USE INDEX?
2476 $use = $this->useIndexClause( implode( ',', (array)$use_index[$alias] ) );
2478 $tableClause .= ' ' . $use;
2481 if ( isset( $ignore_index[$alias] ) ) { // has IGNORE INDEX?
2482 $ignore = $this->ignoreIndexClause(
2483 implode( ',', (array)$ignore_index[$alias] ) );
2484 if ( $ignore != '' ) {
2485 $tableClause .= ' ' . $ignore;
2488 $on = $this->makeList( (array)$conds, self
::LIST_AND
);
2490 $tableClause .= ' ON (' . $on . ')';
2493 $retJOIN[] = $tableClause;
2494 } elseif ( isset( $use_index[$alias] ) ) {
2495 // Is there an INDEX clause for this table?
2496 $tableClause = $joinedTable;
2497 $tableClause .= ' ' . $this->useIndexClause(
2498 implode( ',', (array)$use_index[$alias] )
2501 $ret[] = $tableClause;
2502 } elseif ( isset( $ignore_index[$alias] ) ) {
2503 // Is there an INDEX clause for this table?
2504 $tableClause = $joinedTable;
2505 $tableClause .= ' ' . $this->ignoreIndexClause(
2506 implode( ',', (array)$ignore_index[$alias] )
2509 $ret[] = $tableClause;
2511 $tableClause = $joinedTable;
2513 $ret[] = $tableClause;
2517 // We can't separate explicit JOIN clauses with ',', use ' ' for those
2518 $implicitJoins = $ret ?
implode( ',', $ret ) : "";
2519 $explicitJoins = $retJOIN ?
implode( ' ', $retJOIN ) : "";
2521 // Compile our final table clause
2522 return implode( ' ', [ $implicitJoins, $explicitJoins ] );
2526 * Allows for index remapping in queries where this is not consistent across DBMS
2528 * @param string $index
2531 protected function indexName( $index ) {
2532 return isset( $this->indexAliases
[$index] )
2533 ?
$this->indexAliases
[$index]
2537 public function addQuotes( $s ) {
2538 if ( $s instanceof Blob
) {
2541 if ( $s === null ) {
2543 } elseif ( is_bool( $s ) ) {
2546 # This will also quote numeric values. This should be harmless,
2547 # and protects against weird problems that occur when they really
2548 # _are_ strings such as article titles and string->number->string
2549 # conversion is not 1:1.
2550 return "'" . $this->strencode( $s ) . "'";
2555 * Quotes an identifier using `backticks` or "double quotes" depending on the database type.
2556 * MySQL uses `backticks` while basically everything else uses double quotes.
2557 * Since MySQL is the odd one out here the double quotes are our generic
2558 * and we implement backticks in DatabaseMysqlBase.
2563 public function addIdentifierQuotes( $s ) {
2564 return '"' . str_replace( '"', '""', $s ) . '"';
2568 * Returns if the given identifier looks quoted or not according to
2569 * the database convention for quoting identifiers .
2571 * @note Do not use this to determine if untrusted input is safe.
2572 * A malicious user can trick this function.
2573 * @param string $name
2576 public function isQuotedIdentifier( $name ) {
2577 return $name[0] == '"' && substr( $name, -1, 1 ) == '"';
2582 * @param string $escapeChar
2585 protected function escapeLikeInternal( $s, $escapeChar = '`' ) {
2586 return str_replace( [ $escapeChar, '%', '_' ],
2587 [ "{$escapeChar}{$escapeChar}", "{$escapeChar}%", "{$escapeChar}_" ],
2591 public function buildLike() {
2592 $params = func_get_args();
2594 if ( count( $params ) > 0 && is_array( $params[0] ) ) {
2595 $params = $params[0];
2600 // We use ` instead of \ as the default LIKE escape character, since addQuotes()
2601 // may escape backslashes, creating problems of double escaping. The `
2602 // character has good cross-DBMS compatibility, avoiding special operators
2603 // in MS SQL like ^ and %
2606 foreach ( $params as $value ) {
2607 if ( $value instanceof LikeMatch
) {
2608 $s .= $value->toString();
2610 $s .= $this->escapeLikeInternal( $value, $escapeChar );
2615 $this->addQuotes( $s ) . ' ESCAPE ' . $this->addQuotes( $escapeChar ) . ' ';
2618 public function anyChar() {
2619 return new LikeMatch( '_' );
2622 public function anyString() {
2623 return new LikeMatch( '%' );
2626 public function nextSequenceValue( $seqName ) {
2631 * USE INDEX clause. Unlikely to be useful for anything but MySQL. This
2632 * is only needed because a) MySQL must be as efficient as possible due to
2633 * its use on Wikipedia, and b) MySQL 4.0 is kind of dumb sometimes about
2634 * which index to pick. Anyway, other databases might have different
2635 * indexes on a given table. So don't bother overriding this unless you're
2637 * @param string $index
2640 public function useIndexClause( $index ) {
2645 * IGNORE INDEX clause. Unlikely to be useful for anything but MySQL. This
2646 * is only needed because a) MySQL must be as efficient as possible due to
2647 * its use on Wikipedia, and b) MySQL 4.0 is kind of dumb sometimes about
2648 * which index to pick. Anyway, other databases might have different
2649 * indexes on a given table. So don't bother overriding this unless you're
2651 * @param string $index
2654 public function ignoreIndexClause( $index ) {
2658 public function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__
) {
2659 if ( count( $rows ) == 0 ) {
2664 if ( !is_array( reset( $rows ) ) ) {
2669 $this->startAtomic( $fname, self
::ATOMIC_CANCELABLE
);
2670 $affectedRowCount = 0;
2671 foreach ( $rows as $row ) {
2672 // Delete rows which collide with this one
2673 $indexWhereClauses = [];
2674 foreach ( $uniqueIndexes as $index ) {
2675 $indexColumns = (array)$index;
2676 $indexRowValues = array_intersect_key( $row, array_flip( $indexColumns ) );
2677 if ( count( $indexRowValues ) != count( $indexColumns ) ) {
2678 throw new DBUnexpectedError(
2680 'New record does not provide all values for unique key (' .
2681 implode( ', ', $indexColumns ) . ')'
2683 } elseif ( in_array( null, $indexRowValues, true ) ) {
2684 throw new DBUnexpectedError(
2686 'New record has a null value for unique key (' .
2687 implode( ', ', $indexColumns ) . ')'
2690 $indexWhereClauses[] = $this->makeList( $indexRowValues, LIST_AND
);
2693 if ( $indexWhereClauses ) {
2694 $this->delete( $table, $this->makeList( $indexWhereClauses, LIST_OR
), $fname );
2695 $affectedRowCount +
= $this->affectedRows();
2698 // Now insert the row
2699 $this->insert( $table, $row, $fname );
2700 $affectedRowCount +
= $this->affectedRows();
2702 $this->endAtomic( $fname );
2703 $this->affectedRowCount
= $affectedRowCount;
2704 } catch ( Exception
$e ) {
2705 $this->cancelAtomic( $fname );
2711 * REPLACE query wrapper for MySQL and SQLite, which have a native REPLACE
2714 * @param string $table Table name
2715 * @param array|string $rows Row(s) to insert
2716 * @param string $fname Caller function name
2718 * @return ResultWrapper
2720 protected function nativeReplace( $table, $rows, $fname ) {
2721 $table = $this->tableName( $table );
2724 if ( !is_array( reset( $rows ) ) ) {
2728 $sql = "REPLACE INTO $table (" . implode( ',', array_keys( $rows[0] ) ) . ') VALUES ';
2731 foreach ( $rows as $row ) {
2738 $sql .= '(' . $this->makeList( $row ) . ')';
2741 return $this->query( $sql, $fname );
2744 public function upsert( $table, array $rows, array $uniqueIndexes, array $set,
2747 if ( !count( $rows ) ) {
2748 return true; // nothing to do
2751 if ( !is_array( reset( $rows ) ) ) {
2755 if ( count( $uniqueIndexes ) ) {
2756 $clauses = []; // list WHERE clauses that each identify a single row
2757 foreach ( $rows as $row ) {
2758 foreach ( $uniqueIndexes as $index ) {
2759 $index = is_array( $index ) ?
$index : [ $index ]; // columns
2760 $rowKey = []; // unique key to this row
2761 foreach ( $index as $column ) {
2762 $rowKey[$column] = $row[$column];
2764 $clauses[] = $this->makeList( $rowKey, self
::LIST_AND
);
2767 $where = [ $this->makeList( $clauses, self
::LIST_OR
) ];
2772 $affectedRowCount = 0;
2774 $this->startAtomic( $fname, self
::ATOMIC_CANCELABLE
);
2775 # Update any existing conflicting row(s)
2776 if ( $where !== false ) {
2777 $ok = $this->update( $table, $set, $where, $fname );
2778 $affectedRowCount +
= $this->affectedRows();
2782 # Now insert any non-conflicting row(s)
2783 $ok = $this->insert( $table, $rows, $fname, [ 'IGNORE' ] ) && $ok;
2784 $affectedRowCount +
= $this->affectedRows();
2785 $this->endAtomic( $fname );
2786 $this->affectedRowCount
= $affectedRowCount;
2787 } catch ( Exception
$e ) {
2788 $this->cancelAtomic( $fname );
2795 public function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds,
2799 throw new DBUnexpectedError( $this, __METHOD__
. ' called with empty $conds' );
2802 $delTable = $this->tableName( $delTable );
2803 $joinTable = $this->tableName( $joinTable );
2804 $sql = "DELETE FROM $delTable WHERE $delVar IN (SELECT $joinVar FROM $joinTable ";
2805 if ( $conds != '*' ) {
2806 $sql .= 'WHERE ' . $this->makeList( $conds, self
::LIST_AND
);
2810 $this->query( $sql, $fname );
2813 public function textFieldSize( $table, $field ) {
2814 $table = $this->tableName( $table );
2815 $sql = "SHOW COLUMNS FROM $table LIKE \"$field\";";
2816 $res = $this->query( $sql, __METHOD__
);
2817 $row = $this->fetchObject( $res );
2821 if ( preg_match( '/\((.*)\)/', $row->Type
, $m ) ) {
2830 public function delete( $table, $conds, $fname = __METHOD__
) {
2832 throw new DBUnexpectedError( $this, __METHOD__
. ' called with no conditions' );
2835 $table = $this->tableName( $table );
2836 $sql = "DELETE FROM $table";
2838 if ( $conds != '*' ) {
2839 if ( is_array( $conds ) ) {
2840 $conds = $this->makeList( $conds, self
::LIST_AND
);
2842 $sql .= ' WHERE ' . $conds;
2845 return $this->query( $sql, $fname );
2848 final public function insertSelect(
2849 $destTable, $srcTable, $varMap, $conds,
2850 $fname = __METHOD__
, $insertOptions = [], $selectOptions = [], $selectJoinConds = []
2852 static $hints = [ 'NO_AUTO_COLUMNS' ];
2854 $insertOptions = (array)$insertOptions;
2855 $selectOptions = (array)$selectOptions;
2857 if ( $this->cliMode
&& $this->isInsertSelectSafe( $insertOptions, $selectOptions ) ) {
2858 // For massive migrations with downtime, we don't want to select everything
2859 // into memory and OOM, so do all this native on the server side if possible.
2860 return $this->nativeInsertSelect(
2866 array_diff( $insertOptions, $hints ),
2872 return $this->nonNativeInsertSelect(
2878 array_diff( $insertOptions, $hints ),
2885 * @param array $insertOptions INSERT options
2886 * @param array $selectOptions SELECT options
2887 * @return bool Whether an INSERT SELECT with these options will be replication safe
2890 protected function isInsertSelectSafe( array $insertOptions, array $selectOptions ) {
2895 * Implementation of insertSelect() based on select() and insert()
2897 * @see IDatabase::insertSelect()
2899 * @param string $destTable
2900 * @param string|array $srcTable
2901 * @param array $varMap
2902 * @param array $conds
2903 * @param string $fname
2904 * @param array $insertOptions
2905 * @param array $selectOptions
2906 * @param array $selectJoinConds
2909 protected function nonNativeInsertSelect( $destTable, $srcTable, $varMap, $conds,
2910 $fname = __METHOD__
,
2911 $insertOptions = [], $selectOptions = [], $selectJoinConds = []
2913 // For web requests, do a locking SELECT and then INSERT. This puts the SELECT burden
2914 // on only the master (without needing row-based-replication). It also makes it easy to
2915 // know how big the INSERT is going to be.
2917 foreach ( $varMap as $dstColumn => $sourceColumnOrSql ) {
2918 $fields[] = $this->fieldNameWithAlias( $sourceColumnOrSql, $dstColumn );
2920 $selectOptions[] = 'FOR UPDATE';
2921 $res = $this->select(
2922 $srcTable, implode( ',', $fields ), $conds, $fname, $selectOptions, $selectJoinConds
2929 $affectedRowCount = 0;
2930 $this->startAtomic( $fname, self
::ATOMIC_CANCELABLE
);
2933 foreach ( $res as $row ) {
2934 $rows[] = (array)$row;
2936 // Avoid inserts that are too huge
2937 if ( count( $rows ) >= $this->nonNativeInsertSelectBatchSize
) {
2938 $ok = $this->insert( $destTable, $rows, $fname, $insertOptions );
2942 $affectedRowCount +
= $this->affectedRows();
2946 if ( $rows && $ok ) {
2947 $ok = $this->insert( $destTable, $rows, $fname, $insertOptions );
2949 $affectedRowCount +
= $this->affectedRows();
2953 $this->endAtomic( $fname );
2954 $this->affectedRowCount
= $affectedRowCount;
2956 $this->cancelAtomic( $fname );
2959 } catch ( Exception
$e ) {
2960 $this->cancelAtomic( $fname );
2966 * Native server-side implementation of insertSelect() for situations where
2967 * we don't want to select everything into memory
2969 * @see IDatabase::insertSelect()
2970 * @param string $destTable
2971 * @param string|array $srcTable
2972 * @param array $varMap
2973 * @param array $conds
2974 * @param string $fname
2975 * @param array $insertOptions
2976 * @param array $selectOptions
2977 * @param array $selectJoinConds
2980 protected function nativeInsertSelect( $destTable, $srcTable, $varMap, $conds,
2981 $fname = __METHOD__
,
2982 $insertOptions = [], $selectOptions = [], $selectJoinConds = []
2984 $destTable = $this->tableName( $destTable );
2986 if ( !is_array( $insertOptions ) ) {
2987 $insertOptions = [ $insertOptions ];
2990 $insertOptions = $this->makeInsertOptions( $insertOptions );
2992 $selectSql = $this->selectSQLText(
2994 array_values( $varMap ),
3001 $sql = "INSERT $insertOptions" .
3002 " INTO $destTable (" . implode( ',', array_keys( $varMap ) ) . ') ' .
3005 return $this->query( $sql, $fname );
3009 * Construct a LIMIT query with optional offset. This is used for query
3010 * pages. The SQL should be adjusted so that only the first $limit rows
3011 * are returned. If $offset is provided as well, then the first $offset
3012 * rows should be discarded, and the next $limit rows should be returned.
3013 * If the result of the query is not ordered, then the rows to be returned
3014 * are theoretically arbitrary.
3016 * $sql is expected to be a SELECT, if that makes a difference.
3018 * The version provided by default works in MySQL and SQLite. It will very
3019 * likely need to be overridden for most other DBMSes.
3021 * @param string $sql SQL query we will append the limit too
3022 * @param int $limit The SQL limit
3023 * @param int|bool $offset The SQL offset (default false)
3024 * @throws DBUnexpectedError
3027 public function limitResult( $sql, $limit, $offset = false ) {
3028 if ( !is_numeric( $limit ) ) {
3029 throw new DBUnexpectedError( $this,
3030 "Invalid non-numeric limit passed to limitResult()\n" );
3033 return "$sql LIMIT "
3034 . ( ( is_numeric( $offset ) && $offset != 0 ) ?
"{$offset}," : "" )
3038 public function unionSupportsOrderAndLimit() {
3039 return true; // True for almost every DB supported
3042 public function unionQueries( $sqls, $all ) {
3043 $glue = $all ?
') UNION ALL (' : ') UNION (';
3045 return '(' . implode( $glue, $sqls ) . ')';
3048 public function unionConditionPermutations(
3049 $table, $vars, array $permute_conds, $extra_conds = '', $fname = __METHOD__
,
3050 $options = [], $join_conds = []
3052 // First, build the Cartesian product of $permute_conds
3054 foreach ( $permute_conds as $field => $values ) {
3056 // Skip empty $values
3059 $values = array_unique( $values ); // For sanity
3061 foreach ( $conds as $cond ) {
3062 foreach ( $values as $value ) {
3063 $cond[$field] = $value;
3064 $newConds[] = $cond; // Arrays are by-value, not by-reference, so this works
3070 $extra_conds = $extra_conds === '' ?
[] : (array)$extra_conds;
3072 // If there's just one condition and no subordering, hand off to
3073 // selectSQLText directly.
3074 if ( count( $conds ) === 1 &&
3075 ( !isset( $options['INNER ORDER BY'] ) ||
!$this->unionSupportsOrderAndLimit() )
3077 return $this->selectSQLText(
3078 $table, $vars, $conds[0] +
$extra_conds, $fname, $options, $join_conds
3082 // Otherwise, we need to pull out the order and limit to apply after
3083 // the union. Then build the SQL queries for each set of conditions in
3084 // $conds. Then union them together (using UNION ALL, because the
3085 // product *should* already be distinct).
3086 $orderBy = $this->makeOrderBy( $options );
3087 $limit = isset( $options['LIMIT'] ) ?
$options['LIMIT'] : null;
3088 $offset = isset( $options['OFFSET'] ) ?
$options['OFFSET'] : false;
3089 $all = empty( $options['NOTALL'] ) && !in_array( 'NOTALL', $options );
3090 if ( !$this->unionSupportsOrderAndLimit() ) {
3091 unset( $options['ORDER BY'], $options['LIMIT'], $options['OFFSET'] );
3093 if ( array_key_exists( 'INNER ORDER BY', $options ) ) {
3094 $options['ORDER BY'] = $options['INNER ORDER BY'];
3096 if ( $limit !== null && is_numeric( $offset ) && $offset != 0 ) {
3097 // We need to increase the limit by the offset rather than
3098 // using the offset directly, otherwise it'll skip incorrectly
3099 // in the subqueries.
3100 $options['LIMIT'] = $limit +
$offset;
3101 unset( $options['OFFSET'] );
3106 foreach ( $conds as $cond ) {
3107 $sqls[] = $this->selectSQLText(
3108 $table, $vars, $cond +
$extra_conds, $fname, $options, $join_conds
3111 $sql = $this->unionQueries( $sqls, $all ) . $orderBy;
3112 if ( $limit !== null ) {
3113 $sql = $this->limitResult( $sql, $limit, $offset );
3119 public function conditional( $cond, $trueVal, $falseVal ) {
3120 if ( is_array( $cond ) ) {
3121 $cond = $this->makeList( $cond, self
::LIST_AND
);
3124 return " (CASE WHEN $cond THEN $trueVal ELSE $falseVal END) ";
3127 public function strreplace( $orig, $old, $new ) {
3128 return "REPLACE({$orig}, {$old}, {$new})";
3131 public function getServerUptime() {
3135 public function wasDeadlock() {
3139 public function wasLockTimeout() {
3143 public function wasConnectionLoss() {
3144 return $this->wasConnectionError( $this->lastErrno() );
3147 public function wasReadOnlyError() {
3151 public function wasErrorReissuable() {
3153 $this->wasDeadlock() ||
3154 $this->wasLockTimeout() ||
3155 $this->wasConnectionLoss()
3160 * Do not use this method outside of Database/DBError classes
3162 * @param int|string $errno
3163 * @return bool Whether the given query error was a connection drop
3165 public function wasConnectionError( $errno ) {
3170 * @return bool Whether it is safe to assume the given error only caused statement rollback
3171 * @note This is for backwards compatibility for callers catching DBError exceptions in
3172 * order to ignore problems like duplicate key errors or foriegn key violations
3175 protected function wasKnownStatementRollbackError() {
3176 return false; // don't know; it could have caused a transaction rollback
3179 public function deadlockLoop() {
3180 $args = func_get_args();
3181 $function = array_shift( $args );
3182 $tries = self
::DEADLOCK_TRIES
;
3184 $this->begin( __METHOD__
);
3187 /** @var Exception $e */
3191 $retVal = call_user_func_array( $function, $args );
3193 } catch ( DBQueryError
$e ) {
3194 if ( $this->wasDeadlock() ) {
3195 // Retry after a randomized delay
3196 usleep( mt_rand( self
::DEADLOCK_DELAY_MIN
, self
::DEADLOCK_DELAY_MAX
) );
3198 // Throw the error back up
3202 } while ( --$tries > 0 );
3204 if ( $tries <= 0 ) {
3205 // Too many deadlocks; give up
3206 $this->rollback( __METHOD__
);
3209 $this->commit( __METHOD__
);
3215 public function masterPosWait( DBMasterPos
$pos, $timeout ) {
3216 # Real waits are implemented in the subclass.
3220 public function getReplicaPos() {
3225 public function getMasterPos() {
3230 public function serverIsReadOnly() {
3234 final public function onTransactionResolution( callable
$callback, $fname = __METHOD__
) {
3235 if ( !$this->trxLevel
) {
3236 throw new DBUnexpectedError( $this, "No transaction is active." );
3238 $this->trxEndCallbacks
[] = [ $callback, $fname, $this->currentAtomicSectionId() ];
3241 final public function onTransactionIdle( callable
$callback, $fname = __METHOD__
) {
3242 if ( !$this->trxLevel
&& $this->getTransactionRoundId() ) {
3243 // Start an implicit transaction similar to how query() does
3244 $this->begin( __METHOD__
, self
::TRANSACTION_INTERNAL
);
3245 $this->trxAutomatic
= true;
3248 $this->trxIdleCallbacks
[] = [ $callback, $fname, $this->currentAtomicSectionId() ];
3249 if ( !$this->trxLevel
) {
3250 $this->runOnTransactionIdleCallbacks( self
::TRIGGER_IDLE
);
3254 final public function onTransactionPreCommitOrIdle( callable
$callback, $fname = __METHOD__
) {
3255 if ( !$this->trxLevel
&& $this->getTransactionRoundId() ) {
3256 // Start an implicit transaction similar to how query() does
3257 $this->begin( __METHOD__
, self
::TRANSACTION_INTERNAL
);
3258 $this->trxAutomatic
= true;
3261 if ( $this->trxLevel
) {
3262 $this->trxPreCommitCallbacks
[] = [ $callback, $fname, $this->currentAtomicSectionId() ];
3264 // No transaction is active nor will start implicitly, so make one for this callback
3265 $this->startAtomic( __METHOD__
, self
::ATOMIC_CANCELABLE
);
3267 call_user_func( $callback );
3268 $this->endAtomic( __METHOD__
);
3269 } catch ( Exception
$e ) {
3270 $this->cancelAtomic( __METHOD__
);
3277 * @return AtomicSectionIdentifier|null ID of the topmost atomic section level
3279 private function currentAtomicSectionId() {
3280 if ( $this->trxLevel
&& $this->trxAtomicLevels
) {
3281 $levelInfo = end( $this->trxAtomicLevels
);
3283 return $levelInfo[1];
3290 * @param AtomicSectionIdentifier $old
3291 * @param AtomicSectionIdentifier $new
3293 private function reassignCallbacksForSection(
3294 AtomicSectionIdentifier
$old, AtomicSectionIdentifier
$new
3296 foreach ( $this->trxPreCommitCallbacks
as $key => $info ) {
3297 if ( $info[2] === $old ) {
3298 $this->trxPreCommitCallbacks
[$key][2] = $new;
3301 foreach ( $this->trxIdleCallbacks
as $key => $info ) {
3302 if ( $info[2] === $old ) {
3303 $this->trxIdleCallbacks
[$key][2] = $new;
3306 foreach ( $this->trxEndCallbacks
as $key => $info ) {
3307 if ( $info[2] === $old ) {
3308 $this->trxEndCallbacks
[$key][2] = $new;
3314 * @param AtomicSectionIdentifier[] $sectionIds ID of an actual savepoint
3315 * @throws UnexpectedValueException
3317 private function modifyCallbacksForCancel( array $sectionIds ) {
3318 // Cancel the "on commit" callbacks owned by this savepoint
3319 $this->trxIdleCallbacks
= array_filter(
3320 $this->trxIdleCallbacks
,
3321 function ( $entry ) use ( $sectionIds ) {
3322 return !in_array( $entry[2], $sectionIds, true );
3325 $this->trxPreCommitCallbacks
= array_filter(
3326 $this->trxPreCommitCallbacks
,
3327 function ( $entry ) use ( $sectionIds ) {
3328 return !in_array( $entry[2], $sectionIds, true );
3331 // Make "on resolution" callbacks owned by this savepoint to perceive a rollback
3332 foreach ( $this->trxEndCallbacks
as $key => $entry ) {
3333 if ( in_array( $entry[2], $sectionIds, true ) ) {
3334 $callback = $entry[0];
3335 $this->trxEndCallbacks
[$key][0] = function () use ( $callback ) {
3336 return $callback( self
::TRIGGER_ROLLBACK
);
3342 final public function setTransactionListener( $name, callable
$callback = null ) {
3344 $this->trxRecurringCallbacks
[$name] = $callback;
3346 unset( $this->trxRecurringCallbacks
[$name] );
3351 * Whether to disable running of post-COMMIT/ROLLBACK callbacks
3353 * This method should not be used outside of Database/LoadBalancer
3355 * @param bool $suppress
3358 final public function setTrxEndCallbackSuppression( $suppress ) {
3359 $this->trxEndCallbacksSuppressed
= $suppress;
3363 * Actually run and consume any "on transaction idle/resolution" callbacks.
3365 * This method should not be used outside of Database/LoadBalancer
3367 * @param int $trigger IDatabase::TRIGGER_* constant
3371 public function runOnTransactionIdleCallbacks( $trigger ) {
3372 if ( $this->trxEndCallbacksSuppressed
) {
3376 $autoTrx = $this->getFlag( self
::DBO_TRX
); // automatic begin() enabled?
3377 /** @var Exception $e */
3378 $e = null; // first exception
3379 do { // callbacks may add callbacks :)
3380 $callbacks = array_merge(
3381 $this->trxIdleCallbacks
,
3382 $this->trxEndCallbacks
// include "transaction resolution" callbacks
3384 $this->trxIdleCallbacks
= []; // consumed (and recursion guard)
3385 $this->trxEndCallbacks
= []; // consumed (recursion guard)
3386 foreach ( $callbacks as $callback ) {
3388 list( $phpCallback ) = $callback;
3389 $this->clearFlag( self
::DBO_TRX
); // make each query its own transaction
3390 call_user_func_array( $phpCallback, [ $trigger ] );
3392 $this->setFlag( self
::DBO_TRX
); // restore automatic begin()
3394 $this->clearFlag( self
::DBO_TRX
); // restore auto-commit
3396 } catch ( Exception
$ex ) {
3397 call_user_func( $this->errorLogger
, $ex );
3399 // Some callbacks may use startAtomic/endAtomic, so make sure
3400 // their transactions are ended so other callbacks don't fail
3401 if ( $this->trxLevel() ) {
3402 $this->rollback( __METHOD__
, self
::FLUSHING_INTERNAL
);
3406 } while ( count( $this->trxIdleCallbacks
) );
3408 if ( $e instanceof Exception
) {
3409 throw $e; // re-throw any first exception
3414 * Actually run and consume any "on transaction pre-commit" callbacks.
3416 * This method should not be used outside of Database/LoadBalancer
3421 public function runOnTransactionPreCommitCallbacks() {
3422 $e = null; // first exception
3423 do { // callbacks may add callbacks :)
3424 $callbacks = $this->trxPreCommitCallbacks
;
3425 $this->trxPreCommitCallbacks
= []; // consumed (and recursion guard)
3426 foreach ( $callbacks as $callback ) {
3428 list( $phpCallback ) = $callback;
3429 call_user_func( $phpCallback );
3430 } catch ( Exception
$ex ) {
3431 call_user_func( $this->errorLogger
, $ex );
3435 } while ( count( $this->trxPreCommitCallbacks
) );
3437 if ( $e instanceof Exception
) {
3438 throw $e; // re-throw any first exception
3443 * Actually run any "transaction listener" callbacks.
3445 * This method should not be used outside of Database/LoadBalancer
3447 * @param int $trigger IDatabase::TRIGGER_* constant
3451 public function runTransactionListenerCallbacks( $trigger ) {
3452 if ( $this->trxEndCallbacksSuppressed
) {
3456 /** @var Exception $e */
3457 $e = null; // first exception
3459 foreach ( $this->trxRecurringCallbacks
as $phpCallback ) {
3461 $phpCallback( $trigger, $this );
3462 } catch ( Exception
$ex ) {
3463 call_user_func( $this->errorLogger
, $ex );
3468 if ( $e instanceof Exception
) {
3469 throw $e; // re-throw any first exception
3474 * Create a savepoint
3476 * This is used internally to implement atomic sections. It should not be
3480 * @param string $identifier Identifier for the savepoint
3481 * @param string $fname Calling function name
3483 protected function doSavepoint( $identifier, $fname ) {
3484 $this->query( 'SAVEPOINT ' . $this->addIdentifierQuotes( $identifier ), $fname );
3488 * Release a savepoint
3490 * This is used internally to implement atomic sections. It should not be
3494 * @param string $identifier Identifier for the savepoint
3495 * @param string $fname Calling function name
3497 protected function doReleaseSavepoint( $identifier, $fname ) {
3498 $this->query( 'RELEASE SAVEPOINT ' . $this->addIdentifierQuotes( $identifier ), $fname );
3502 * Rollback to a savepoint
3504 * This is used internally to implement atomic sections. It should not be
3508 * @param string $identifier Identifier for the savepoint
3509 * @param string $fname Calling function name
3511 protected function doRollbackToSavepoint( $identifier, $fname ) {
3512 $this->query( 'ROLLBACK TO SAVEPOINT ' . $this->addIdentifierQuotes( $identifier ), $fname );
3516 * @param string $fname
3519 private function nextSavepointId( $fname ) {
3520 $savepointId = self
::$SAVEPOINT_PREFIX . ++
$this->trxAtomicCounter
;
3521 if ( strlen( $savepointId ) > 30 ) {
3522 // 30 == Oracle's identifier length limit (pre 12c)
3523 // With a 22 character prefix, that puts the highest number at 99999999.
3524 throw new DBUnexpectedError(
3526 'There have been an excessively large number of atomic sections in a transaction'
3527 . " started by $this->trxFname (at $fname)"
3531 return $savepointId;
3534 final public function startAtomic(
3535 $fname = __METHOD__
, $cancelable = self
::ATOMIC_NOT_CANCELABLE
3537 $savepointId = $cancelable === self
::ATOMIC_CANCELABLE ? self
::$NOT_APPLICABLE : null;
3539 if ( !$this->trxLevel
) {
3540 $this->begin( $fname, self
::TRANSACTION_INTERNAL
);
3541 // If DBO_TRX is set, a series of startAtomic/endAtomic pairs will result
3542 // in all changes being in one transaction to keep requests transactional.
3543 if ( $this->getFlag( self
::DBO_TRX
) ) {
3544 // Since writes could happen in between the topmost atomic sections as part
3545 // of the transaction, those sections will need savepoints.
3546 $savepointId = $this->nextSavepointId( $fname );
3547 $this->doSavepoint( $savepointId, $fname );
3549 $this->trxAutomaticAtomic
= true;
3551 } elseif ( $cancelable === self
::ATOMIC_CANCELABLE
) {
3552 $savepointId = $this->nextSavepointId( $fname );
3553 $this->doSavepoint( $savepointId, $fname );
3556 $sectionId = new AtomicSectionIdentifier
;
3557 $this->trxAtomicLevels
[] = [ $fname, $sectionId, $savepointId ];
3562 final public function endAtomic( $fname = __METHOD__
) {
3563 if ( !$this->trxLevel ||
!$this->trxAtomicLevels
) {
3564 throw new DBUnexpectedError( $this, "No atomic section is open (got $fname)." );
3567 // Check if the current section matches $fname
3568 $pos = count( $this->trxAtomicLevels
) - 1;
3569 list( $savedFname, $sectionId, $savepointId ) = $this->trxAtomicLevels
[$pos];
3571 if ( $savedFname !== $fname ) {
3572 throw new DBUnexpectedError(
3574 "Invalid atomic section ended (got $fname but expected $savedFname)."
3578 // Remove the last section (no need to re-index the array)
3579 array_pop( $this->trxAtomicLevels
);
3581 if ( !$this->trxAtomicLevels
&& $this->trxAutomaticAtomic
) {
3582 $this->commit( $fname, self
::FLUSHING_INTERNAL
);
3583 } elseif ( $savepointId !== null && $savepointId !== self
::$NOT_APPLICABLE ) {
3584 $this->doReleaseSavepoint( $savepointId, $fname );
3587 // Hoist callback ownership for callbacks in the section that just ended;
3588 // all callbacks should have an owner that is present in trxAtomicLevels.
3589 $currentSectionId = $this->currentAtomicSectionId();
3590 if ( $currentSectionId ) {
3591 $this->reassignCallbacksForSection( $sectionId, $currentSectionId );
3595 final public function cancelAtomic(
3596 $fname = __METHOD__
, AtomicSectionIdentifier
$sectionId = null
3598 if ( !$this->trxLevel ||
!$this->trxAtomicLevels
) {
3599 throw new DBUnexpectedError( $this, "No atomic section is open (got $fname)." );
3602 if ( $sectionId !== null ) {
3603 // Find the (last) section with the given $sectionId
3605 foreach ( $this->trxAtomicLevels
as $i => list( $asFname, $asId, $spId ) ) {
3606 if ( $asId === $sectionId ) {
3611 throw new DBUnexpectedError( "Atomic section not found (for $fname)" );
3613 // Remove all descendant sections and re-index the array
3615 $len = count( $this->trxAtomicLevels
);
3616 for ( $i = $pos +
1; $i < $len; ++
$i ) {
3617 $excisedIds[] = $this->trxAtomicLevels
[$i][1];
3619 $this->trxAtomicLevels
= array_slice( $this->trxAtomicLevels
, 0, $pos +
1 );
3620 $this->modifyCallbacksForCancel( $excisedIds );
3623 // Check if the current section matches $fname
3624 $pos = count( $this->trxAtomicLevels
) - 1;
3625 list( $savedFname, $savedSectionId, $savepointId ) = $this->trxAtomicLevels
[$pos];
3627 if ( $savedFname !== $fname ) {
3628 throw new DBUnexpectedError(
3630 "Invalid atomic section ended (got $fname but expected $savedFname)."
3634 // Remove the last section (no need to re-index the array)
3635 array_pop( $this->trxAtomicLevels
);
3636 $this->modifyCallbacksForCancel( [ $savedSectionId ] );
3638 if ( $savepointId !== null ) {
3639 // Rollback the transaction to the state just before this atomic section
3640 if ( $savepointId === self
::$NOT_APPLICABLE ) {
3641 $this->rollback( $fname, self
::FLUSHING_INTERNAL
);
3643 $this->doRollbackToSavepoint( $savepointId, $fname );
3644 $this->trxStatus
= self
::STATUS_TRX_OK
; // no exception; recovered
3645 $this->trxStatusIgnoredCause
= null;
3647 } elseif ( $this->trxStatus
> self
::STATUS_TRX_ERROR
) {
3648 // Put the transaction into an error state if it's not already in one
3649 $this->trxStatus
= self
::STATUS_TRX_ERROR
;
3650 $this->trxStatusCause
= new DBUnexpectedError(
3652 "Uncancelable atomic section canceled (got $fname)."
3656 $this->affectedRowCount
= 0; // for the sake of consistency
3659 final public function doAtomicSection(
3660 $fname, callable
$callback, $cancelable = self
::ATOMIC_NOT_CANCELABLE
3662 $sectionId = $this->startAtomic( $fname, $cancelable );
3664 $res = call_user_func_array( $callback, [ $this, $fname ] );
3665 } catch ( Exception
$e ) {
3666 $this->cancelAtomic( $fname, $sectionId );
3670 $this->endAtomic( $fname );
3675 final public function begin( $fname = __METHOD__
, $mode = self
::TRANSACTION_EXPLICIT
) {
3676 static $modes = [ self
::TRANSACTION_EXPLICIT
, self
::TRANSACTION_INTERNAL
];
3677 if ( !in_array( $mode, $modes, true ) ) {
3678 throw new DBUnexpectedError( $this, "$fname: invalid mode parameter '$mode'." );
3681 // Protect against mismatched atomic section, transaction nesting, and snapshot loss
3682 if ( $this->trxLevel
) {
3683 if ( $this->trxAtomicLevels
) {
3684 $levels = $this->flatAtomicSectionList();
3685 $msg = "$fname: Got explicit BEGIN while atomic section(s) $levels are open.";
3686 throw new DBUnexpectedError( $this, $msg );
3687 } elseif ( !$this->trxAutomatic
) {
3688 $msg = "$fname: Explicit transaction already active (from {$this->trxFname}).";
3689 throw new DBUnexpectedError( $this, $msg );
3691 $msg = "$fname: Implicit transaction already active (from {$this->trxFname}).";
3692 throw new DBUnexpectedError( $this, $msg );
3694 } elseif ( $this->getFlag( self
::DBO_TRX
) && $mode !== self
::TRANSACTION_INTERNAL
) {
3695 $msg = "$fname: Implicit transaction expected (DBO_TRX set).";
3696 throw new DBUnexpectedError( $this, $msg );
3699 // Avoid fatals if close() was called
3700 $this->assertOpen();
3702 $this->doBegin( $fname );
3703 $this->trxStatus
= self
::STATUS_TRX_OK
;
3704 $this->trxStatusIgnoredCause
= null;
3705 $this->trxAtomicCounter
= 0;
3706 $this->trxTimestamp
= microtime( true );
3707 $this->trxFname
= $fname;
3708 $this->trxDoneWrites
= false;
3709 $this->trxAutomaticAtomic
= false;
3710 $this->trxAtomicLevels
= [];
3711 $this->trxShortId
= sprintf( '%06x', mt_rand( 0, 0xffffff ) );
3712 $this->trxWriteDuration
= 0.0;
3713 $this->trxWriteQueryCount
= 0;
3714 $this->trxWriteAffectedRows
= 0;
3715 $this->trxWriteAdjDuration
= 0.0;
3716 $this->trxWriteAdjQueryCount
= 0;
3717 $this->trxWriteCallers
= [];
3718 // First SELECT after BEGIN will establish the snapshot in REPEATABLE-READ.
3719 // Get an estimate of the replication lag before any such queries.
3720 $this->trxReplicaLag
= null; // clear cached value first
3721 $this->trxReplicaLag
= $this->getApproximateLagStatus()['lag'];
3722 // T147697: make explicitTrxActive() return true until begin() finishes. This way, no
3723 // caller will think its OK to muck around with the transaction just because startAtomic()
3724 // has not yet completed (e.g. setting trxAtomicLevels).
3725 $this->trxAutomatic
= ( $mode === self
::TRANSACTION_INTERNAL
);
3729 * Issues the BEGIN command to the database server.
3731 * @see Database::begin()
3732 * @param string $fname
3734 protected function doBegin( $fname ) {
3735 $this->query( 'BEGIN', $fname );
3736 $this->trxLevel
= 1;
3739 final public function commit( $fname = __METHOD__
, $flush = self
::FLUSHING_ONE
) {
3740 static $modes = [ self
::FLUSHING_ONE
, self
::FLUSHING_ALL_PEERS
, self
::FLUSHING_INTERNAL
];
3741 if ( !in_array( $flush, $modes, true ) ) {
3742 throw new DBUnexpectedError( $this, "$fname: invalid flush parameter '$flush'." );
3745 if ( $this->trxLevel
&& $this->trxAtomicLevels
) {
3746 // There are still atomic sections open; this cannot be ignored
3747 $levels = $this->flatAtomicSectionList();
3748 throw new DBUnexpectedError(
3750 "$fname: Got COMMIT while atomic sections $levels are still open."
3754 if ( $flush === self
::FLUSHING_INTERNAL ||
$flush === self
::FLUSHING_ALL_PEERS
) {
3755 if ( !$this->trxLevel
) {
3756 return; // nothing to do
3757 } elseif ( !$this->trxAutomatic
) {
3758 throw new DBUnexpectedError(
3760 "$fname: Flushing an explicit transaction, getting out of sync."
3764 if ( !$this->trxLevel
) {
3765 $this->queryLogger
->error(
3766 "$fname: No transaction to commit, something got out of sync." );
3767 return; // nothing to do
3768 } elseif ( $this->trxAutomatic
) {
3769 throw new DBUnexpectedError(
3771 "$fname: Expected mass commit of all peer transactions (DBO_TRX set)."
3776 // Avoid fatals if close() was called
3777 $this->assertOpen();
3779 $this->runOnTransactionPreCommitCallbacks();
3780 $writeTime = $this->pendingWriteQueryDuration( self
::ESTIMATE_DB_APPLY
);
3781 $this->doCommit( $fname );
3782 $this->trxStatus
= self
::STATUS_TRX_NONE
;
3783 if ( $this->trxDoneWrites
) {
3784 $this->lastWriteTime
= microtime( true );
3785 $this->trxProfiler
->transactionWritingOut(
3790 $this->trxWriteAffectedRows
3794 $this->runOnTransactionIdleCallbacks( self
::TRIGGER_COMMIT
);
3795 $this->runTransactionListenerCallbacks( self
::TRIGGER_COMMIT
);
3799 * Issues the COMMIT command to the database server.
3801 * @see Database::commit()
3802 * @param string $fname
3804 protected function doCommit( $fname ) {
3805 if ( $this->trxLevel
) {
3806 $this->query( 'COMMIT', $fname );
3807 $this->trxLevel
= 0;
3811 final public function rollback( $fname = __METHOD__
, $flush = '' ) {
3812 $trxActive = $this->trxLevel
;
3814 if ( $flush !== self
::FLUSHING_INTERNAL
&& $flush !== self
::FLUSHING_ALL_PEERS
) {
3815 if ( $this->getFlag( self
::DBO_TRX
) ) {
3816 throw new DBUnexpectedError(
3818 "$fname: Expected mass rollback of all peer transactions (DBO_TRX set)."
3824 // Avoid fatals if close() was called
3825 $this->assertOpen();
3827 $this->doRollback( $fname );
3828 $this->trxStatus
= self
::STATUS_TRX_NONE
;
3829 $this->trxAtomicLevels
= [];
3830 if ( $this->trxDoneWrites
) {
3831 $this->trxProfiler
->transactionWritingOut(
3839 // Clear any commit-dependant callbacks. They might even be present
3840 // only due to transaction rounds, with no SQL transaction being active
3841 $this->trxIdleCallbacks
= [];
3842 $this->trxPreCommitCallbacks
= [];
3846 $this->runOnTransactionIdleCallbacks( self
::TRIGGER_ROLLBACK
);
3847 } catch ( Exception
$e ) {
3848 // already logged; finish and let LoadBalancer move on during mass-rollback
3851 $this->runTransactionListenerCallbacks( self
::TRIGGER_ROLLBACK
);
3852 } catch ( Exception
$e ) {
3853 // already logged; let LoadBalancer move on during mass-rollback
3856 $this->affectedRowCount
= 0; // for the sake of consistency
3861 * Issues the ROLLBACK command to the database server.
3863 * @see Database::rollback()
3864 * @param string $fname
3866 protected function doRollback( $fname ) {
3867 if ( $this->trxLevel
) {
3868 # Disconnects cause rollback anyway, so ignore those errors
3869 $ignoreErrors = true;
3870 $this->query( 'ROLLBACK', $fname, $ignoreErrors );
3871 $this->trxLevel
= 0;
3875 public function flushSnapshot( $fname = __METHOD__
) {
3876 if ( $this->writesOrCallbacksPending() ||
$this->explicitTrxActive() ) {
3877 // This only flushes transactions to clear snapshots, not to write data
3878 $fnames = implode( ', ', $this->pendingWriteAndCallbackCallers() );
3879 throw new DBUnexpectedError(
3881 "$fname: Cannot flush snapshot because writes are pending ($fnames)."
3885 $this->commit( $fname, self
::FLUSHING_INTERNAL
);
3888 public function explicitTrxActive() {
3889 return $this->trxLevel
&& ( $this->trxAtomicLevels ||
!$this->trxAutomatic
);
3892 public function duplicateTableStructure(
3893 $oldName, $newName, $temporary = false, $fname = __METHOD__
3895 throw new RuntimeException( __METHOD__
. ' is not implemented in descendant class' );
3898 public function listTables( $prefix = null, $fname = __METHOD__
) {
3899 throw new RuntimeException( __METHOD__
. ' is not implemented in descendant class' );
3902 public function listViews( $prefix = null, $fname = __METHOD__
) {
3903 throw new RuntimeException( __METHOD__
. ' is not implemented in descendant class' );
3906 public function timestamp( $ts = 0 ) {
3907 $t = new ConvertibleTimestamp( $ts );
3908 // Let errors bubble up to avoid putting garbage in the DB
3909 return $t->getTimestamp( TS_MW
);
3912 public function timestampOrNull( $ts = null ) {
3913 if ( is_null( $ts ) ) {
3916 return $this->timestamp( $ts );
3920 public function affectedRows() {
3921 return ( $this->affectedRowCount
=== null )
3922 ?
$this->fetchAffectedRowCount() // default to driver value
3923 : $this->affectedRowCount
;
3927 * @return int Number of retrieved rows according to the driver
3929 abstract protected function fetchAffectedRowCount();
3932 * Take the result from a query, and wrap it in a ResultWrapper if
3933 * necessary. Boolean values are passed through as is, to indicate success
3934 * of write queries or failure.
3936 * Once upon a time, Database::query() returned a bare MySQL result
3937 * resource, and it was necessary to call this function to convert it to
3938 * a wrapper. Nowadays, raw database objects are never exposed to external
3939 * callers, so this is unnecessary in external code.
3941 * @param bool|ResultWrapper|resource|object $result
3942 * @return bool|ResultWrapper
3944 protected function resultObject( $result ) {
3947 } elseif ( $result instanceof ResultWrapper
) {
3949 } elseif ( $result === true ) {
3950 // Successful write query
3953 return new ResultWrapper( $this, $result );
3957 public function ping( &$rtt = null ) {
3958 // Avoid hitting the server if it was hit recently
3959 if ( $this->isOpen() && ( microtime( true ) - $this->lastPing
) < self
::PING_TTL
) {
3960 if ( !func_num_args() ||
$this->rttEstimate
> 0 ) {
3961 $rtt = $this->rttEstimate
;
3962 return true; // don't care about $rtt
3966 // This will reconnect if possible or return false if not
3967 $this->clearFlag( self
::DBO_TRX
, self
::REMEMBER_PRIOR
);
3968 $ok = ( $this->query( self
::PING_QUERY
, __METHOD__
, true ) !== false );
3969 $this->restoreFlags( self
::RESTORE_PRIOR
);
3972 $rtt = $this->rttEstimate
;
3979 * Close any existing (dead) database connection and open a new connection
3981 * @param string $fname
3982 * @return bool True if new connection is opened successfully, false if error
3984 protected function replaceLostConnection( $fname ) {
3985 $this->closeConnection();
3986 $this->opened
= false;
3987 $this->conn
= false;
3989 $this->open( $this->server
, $this->user
, $this->password
, $this->dbName
);
3990 $this->lastPing
= microtime( true );
3993 $this->connLogger
->warning(
3994 $fname . ': lost connection to {dbserver}; reconnected',
3996 'dbserver' => $this->getServer(),
3997 'trace' => ( new RuntimeException() )->getTraceAsString()
4000 } catch ( DBConnectionError
$e ) {
4003 $this->connLogger
->error(
4004 $fname . ': lost connection to {dbserver} permanently',
4005 [ 'dbserver' => $this->getServer() ]
4009 $this->handleSessionLoss();
4014 public function getSessionLagStatus() {
4015 return $this->getRecordedTransactionLagStatus() ?
: $this->getApproximateLagStatus();
4019 * Get the replica DB lag when the current transaction started
4021 * This is useful when transactions might use snapshot isolation
4022 * (e.g. REPEATABLE-READ in innodb), so the "real" lag of that data
4023 * is this lag plus transaction duration. If they don't, it is still
4024 * safe to be pessimistic. This returns null if there is no transaction.
4026 * This returns null if the lag status for this transaction was not yet recorded.
4028 * @return array|null ('lag': seconds or false on error, 'since': UNIX timestamp of BEGIN)
4031 final protected function getRecordedTransactionLagStatus() {
4032 return ( $this->trxLevel
&& $this->trxReplicaLag
!== null )
4033 ?
[ 'lag' => $this->trxReplicaLag
, 'since' => $this->trxTimestamp() ]
4038 * Get a replica DB lag estimate for this server
4040 * @return array ('lag': seconds or false on error, 'since': UNIX timestamp of estimate)
4043 protected function getApproximateLagStatus() {
4045 'lag' => $this->getLBInfo( 'replica' ) ?
$this->getLag() : 0,
4046 'since' => microtime( true )
4051 * Merge the result of getSessionLagStatus() for several DBs
4052 * using the most pessimistic values to estimate the lag of
4053 * any data derived from them in combination
4055 * This is information is useful for caching modules
4057 * @see WANObjectCache::set()
4058 * @see WANObjectCache::getWithSetCallback()
4060 * @param IDatabase $db1
4061 * @param IDatabase $db2 [optional]
4062 * @return array Map of values:
4063 * - lag: highest lag of any of the DBs or false on error (e.g. replication stopped)
4064 * - since: oldest UNIX timestamp of any of the DB lag estimates
4065 * - pending: whether any of the DBs have uncommitted changes
4069 public static function getCacheSetOptions( IDatabase
$db1, IDatabase
$db2 = null ) {
4070 $res = [ 'lag' => 0, 'since' => INF
, 'pending' => false ];
4071 foreach ( func_get_args() as $db ) {
4072 /** @var IDatabase $db */
4073 $status = $db->getSessionLagStatus();
4074 if ( $status['lag'] === false ) {
4075 $res['lag'] = false;
4076 } elseif ( $res['lag'] !== false ) {
4077 $res['lag'] = max( $res['lag'], $status['lag'] );
4079 $res['since'] = min( $res['since'], $status['since'] );
4080 $res['pending'] = $res['pending'] ?
: $db->writesPending();
4086 public function getLag() {
4090 public function maxListLen() {
4094 public function encodeBlob( $b ) {
4098 public function decodeBlob( $b ) {
4099 if ( $b instanceof Blob
) {
4105 public function setSessionOptions( array $options ) {
4108 public function sourceFile(
4110 callable
$lineCallback = null,
4111 callable
$resultCallback = null,
4113 callable
$inputCallback = null
4115 Wikimedia\
suppressWarnings();
4116 $fp = fopen( $filename, 'r' );
4117 Wikimedia\restoreWarnings
();
4119 if ( false === $fp ) {
4120 throw new RuntimeException( "Could not open \"{$filename}\".\n" );
4124 $fname = __METHOD__
. "( $filename )";
4128 $error = $this->sourceStream(
4129 $fp, $lineCallback, $resultCallback, $fname, $inputCallback );
4130 } catch ( Exception
$e ) {
4140 public function setSchemaVars( $vars ) {
4141 $this->schemaVars
= $vars;
4144 public function sourceStream(
4146 callable
$lineCallback = null,
4147 callable
$resultCallback = null,
4148 $fname = __METHOD__
,
4149 callable
$inputCallback = null
4151 $delimiterReset = new ScopedCallback(
4152 function ( $delimiter ) {
4153 $this->delimiter
= $delimiter;
4155 [ $this->delimiter
]
4159 while ( !feof( $fp ) ) {
4160 if ( $lineCallback ) {
4161 call_user_func( $lineCallback );
4164 $line = trim( fgets( $fp ) );
4166 if ( $line == '' ) {
4170 if ( '-' == $line[0] && '-' == $line[1] ) {
4178 $done = $this->streamStatementEnd( $cmd, $line );
4182 if ( $done ||
feof( $fp ) ) {
4183 $cmd = $this->replaceVars( $cmd );
4185 if ( $inputCallback ) {
4186 $callbackResult = call_user_func( $inputCallback, $cmd );
4188 if ( is_string( $callbackResult ) ||
!$callbackResult ) {
4189 $cmd = $callbackResult;
4194 $res = $this->query( $cmd, $fname );
4196 if ( $resultCallback ) {
4197 call_user_func( $resultCallback, $res, $this );
4200 if ( false === $res ) {
4201 $err = $this->lastError();
4203 return "Query \"{$cmd}\" failed with error code \"$err\".\n";
4210 ScopedCallback
::consume( $delimiterReset );
4215 * Called by sourceStream() to check if we've reached a statement end
4217 * @param string &$sql SQL assembled so far
4218 * @param string &$newLine New line about to be added to $sql
4219 * @return bool Whether $newLine contains end of the statement
4221 public function streamStatementEnd( &$sql, &$newLine ) {
4222 if ( $this->delimiter
) {
4224 $newLine = preg_replace(
4225 '/' . preg_quote( $this->delimiter
, '/' ) . '$/', '', $newLine );
4226 if ( $newLine != $prev ) {
4235 * Database independent variable replacement. Replaces a set of variables
4236 * in an SQL statement with their contents as given by $this->getSchemaVars().
4238 * Supports '{$var}' `{$var}` and / *$var* / (without the spaces) style variables.
4240 * - '{$var}' should be used for text and is passed through the database's
4242 * - `{$var}` should be used for identifiers (e.g. table and database names).
4243 * It is passed through the database's addIdentifierQuotes method which
4244 * can be overridden if the database uses something other than backticks.
4245 * - / *_* / or / *$wgDBprefix* / passes the name that follows through the
4246 * database's tableName method.
4247 * - / *i* / passes the name that follows through the database's indexName method.
4248 * - In all other cases, / *$var* / is left unencoded. Except for table options,
4249 * its use should be avoided. In 1.24 and older, string encoding was applied.
4251 * @param string $ins SQL statement to replace variables in
4252 * @return string The new SQL statement with variables replaced
4254 protected function replaceVars( $ins ) {
4255 $vars = $this->getSchemaVars();
4256 return preg_replace_callback(
4258 /\* (\$wgDBprefix|[_i]) \*/ (\w*) | # 1-2. tableName, indexName
4259 \'\{\$ (\w+) }\' | # 3. addQuotes
4260 `\{\$ (\w+) }` | # 4. addIdentifierQuotes
4261 /\*\$ (\w+) \*/ # 5. leave unencoded
4263 function ( $m ) use ( $vars ) {
4264 // Note: Because of <https://bugs.php.net/bug.php?id=51881>,
4265 // check for both nonexistent keys *and* the empty string.
4266 if ( isset( $m[1] ) && $m[1] !== '' ) {
4267 if ( $m[1] === 'i' ) {
4268 return $this->indexName( $m[2] );
4270 return $this->tableName( $m[2] );
4272 } elseif ( isset( $m[3] ) && $m[3] !== '' && array_key_exists( $m[3], $vars ) ) {
4273 return $this->addQuotes( $vars[$m[3]] );
4274 } elseif ( isset( $m[4] ) && $m[4] !== '' && array_key_exists( $m[4], $vars ) ) {
4275 return $this->addIdentifierQuotes( $vars[$m[4]] );
4276 } elseif ( isset( $m[5] ) && $m[5] !== '' && array_key_exists( $m[5], $vars ) ) {
4277 return $vars[$m[5]];
4287 * Get schema variables. If none have been set via setSchemaVars(), then
4288 * use some defaults from the current object.
4292 protected function getSchemaVars() {
4293 if ( $this->schemaVars
) {
4294 return $this->schemaVars
;
4296 return $this->getDefaultSchemaVars();
4301 * Get schema variables to use if none have been set via setSchemaVars().
4303 * Override this in derived classes to provide variables for tables.sql
4304 * and SQL patch files.
4308 protected function getDefaultSchemaVars() {
4312 public function lockIsFree( $lockName, $method ) {
4313 // RDBMs methods for checking named locks may or may not count this thread itself.
4314 // In MySQL, IS_FREE_LOCK() returns 0 if the thread already has the lock. This is
4315 // the behavior choosen by the interface for this method.
4316 return !isset( $this->namedLocksHeld
[$lockName] );
4319 public function lock( $lockName, $method, $timeout = 5 ) {
4320 $this->namedLocksHeld
[$lockName] = 1;
4325 public function unlock( $lockName, $method ) {
4326 unset( $this->namedLocksHeld
[$lockName] );
4331 public function getScopedLockAndFlush( $lockKey, $fname, $timeout ) {
4332 if ( $this->writesOrCallbacksPending() ) {
4333 // This only flushes transactions to clear snapshots, not to write data
4334 $fnames = implode( ', ', $this->pendingWriteAndCallbackCallers() );
4335 throw new DBUnexpectedError(
4337 "$fname: Cannot flush pre-lock snapshot because writes are pending ($fnames)."
4341 if ( !$this->lock( $lockKey, $fname, $timeout ) ) {
4345 $unlocker = new ScopedCallback( function () use ( $lockKey, $fname ) {
4346 if ( $this->trxLevel() ) {
4347 // There is a good chance an exception was thrown, causing any early return
4348 // from the caller. Let any error handler get a chance to issue rollback().
4349 // If there isn't one, let the error bubble up and trigger server-side rollback.
4350 $this->onTransactionResolution(
4351 function () use ( $lockKey, $fname ) {
4352 $this->unlock( $lockKey, $fname );
4357 $this->unlock( $lockKey, $fname );
4361 $this->commit( $fname, self
::FLUSHING_INTERNAL
);
4366 public function namedLocksEnqueue() {
4370 public function tableLocksHaveTransactionScope() {
4374 final public function lockTables( array $read, array $write, $method ) {
4375 if ( $this->writesOrCallbacksPending() ) {
4376 throw new DBUnexpectedError( $this, "Transaction writes or callbacks still pending." );
4379 if ( $this->tableLocksHaveTransactionScope() ) {
4380 $this->startAtomic( $method );
4383 return $this->doLockTables( $read, $write, $method );
4387 * Helper function for lockTables() that handles the actual table locking
4389 * @param array $read Array of tables to lock for read access
4390 * @param array $write Array of tables to lock for write access
4391 * @param string $method Name of caller
4394 protected function doLockTables( array $read, array $write, $method ) {
4398 final public function unlockTables( $method ) {
4399 if ( $this->tableLocksHaveTransactionScope() ) {
4400 $this->endAtomic( $method );
4402 return true; // locks released on COMMIT/ROLLBACK
4405 return $this->doUnlockTables( $method );
4409 * Helper function for unlockTables() that handles the actual table unlocking
4411 * @param string $method Name of caller
4414 protected function doUnlockTables( $method ) {
4420 * @param string $tableName
4421 * @param string $fName
4422 * @return bool|ResultWrapper
4425 public function dropTable( $tableName, $fName = __METHOD__
) {
4426 if ( !$this->tableExists( $tableName, $fName ) ) {
4429 $sql = "DROP TABLE " . $this->tableName( $tableName ) . " CASCADE";
4431 return $this->query( $sql, $fName );
4434 public function getInfinity() {
4438 public function encodeExpiry( $expiry ) {
4439 return ( $expiry == '' ||
$expiry == 'infinity' ||
$expiry == $this->getInfinity() )
4440 ?
$this->getInfinity()
4441 : $this->timestamp( $expiry );
4444 public function decodeExpiry( $expiry, $format = TS_MW
) {
4445 if ( $expiry == '' ||
$expiry == 'infinity' ||
$expiry == $this->getInfinity() ) {
4449 return ConvertibleTimestamp
::convert( $format, $expiry );
4452 public function setBigSelects( $value = true ) {
4456 public function isReadOnly() {
4457 return ( $this->getReadOnlyReason() !== false );
4461 * @return string|bool Reason this DB is read-only or false if it is not
4463 protected function getReadOnlyReason() {
4464 $reason = $this->getLBInfo( 'readOnlyReason' );
4466 return is_string( $reason ) ?
$reason : false;
4469 public function setTableAliases( array $aliases ) {
4470 $this->tableAliases
= $aliases;
4473 public function setIndexAliases( array $aliases ) {
4474 $this->indexAliases
= $aliases;
4478 * Get the underlying binding connection handle
4480 * Makes sure the connection resource is set (disconnects and ping() failure can unset it).
4481 * This catches broken callers than catch and ignore disconnection exceptions.
4482 * Unlike checking isOpen(), this is safe to call inside of open().
4485 * @throws DBUnexpectedError
4488 protected function getBindingHandle() {
4489 if ( !$this->conn
) {
4490 throw new DBUnexpectedError(
4492 'DB connection was already closed or the connection dropped.'
4503 public function __toString() {
4504 return (string)$this->conn
;
4508 * Make sure that copies do not share the same client binding handle
4509 * @throws DBConnectionError
4511 public function __clone() {
4512 $this->connLogger
->warning(
4513 "Cloning " . static::class . " is not recomended; forking connection:\n" .
4514 ( new RuntimeException() )->getTraceAsString()
4517 if ( $this->isOpen() ) {
4518 // Open a new connection resource without messing with the old one
4519 $this->opened
= false;
4520 $this->conn
= false;
4521 $this->trxEndCallbacks
= []; // don't copy
4522 $this->handleSessionLoss(); // no trx or locks anymore
4523 $this->open( $this->server
, $this->user
, $this->password
, $this->dbName
);
4524 $this->lastPing
= microtime( true );
4529 * Called by serialize. Throw an exception when DB connection is serialized.
4530 * This causes problems on some database engines because the connection is
4531 * not restored on unserialize.
4533 public function __sleep() {
4534 throw new RuntimeException( 'Database serialization may cause problems, since ' .
4535 'the connection is not restored on wakeup.' );
4539 * Run a few simple sanity checks and close dangling connections
4541 public function __destruct() {
4542 if ( $this->trxLevel
&& $this->trxDoneWrites
) {
4543 trigger_error( "Uncommitted DB writes (transaction from {$this->trxFname})." );
4546 $danglingWriters = $this->pendingWriteAndCallbackCallers();
4547 if ( $danglingWriters ) {
4548 $fnames = implode( ', ', $danglingWriters );
4549 trigger_error( "DB transaction writes or callbacks still pending ($fnames)." );
4552 if ( $this->conn
) {
4553 // Avoid connection leaks for sanity. Normally, resources close at script completion.
4554 // The connection might already be closed in zend/hhvm by now, so suppress warnings.
4555 Wikimedia\
suppressWarnings();
4556 $this->closeConnection();
4557 Wikimedia\restoreWarnings
();
4558 $this->conn
= false;
4559 $this->opened
= false;
4564 class_alias( Database
::class, 'DatabaseBase' ); // b/c for old name
4565 class_alias( Database
::class, 'Database' ); // b/c global alias