3 * @defgroup Database Database
5 * This file deals with database interface functions
6 * and query specifics/optimisations.
8 * This program is free software; you can redistribute it and/or modify
9 * it under the terms of the GNU General Public License as published by
10 * the Free Software Foundation; either version 2 of the License, or
11 * (at your option) any later version.
13 * This program is distributed in the hope that it will be useful,
14 * but WITHOUT ANY WARRANTY; without even the implied warranty of
15 * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
16 * GNU General Public License for more details.
18 * You should have received a copy of the GNU General Public License along
19 * with this program; if not, write to the Free Software Foundation, Inc.,
20 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301, USA.
21 * http://www.gnu.org/copyleft/gpl.html
26 namespace Wikimedia\Rdbms
;
28 use Psr\Log\LoggerAwareInterface
;
29 use Psr\Log\LoggerInterface
;
30 use Psr\Log\NullLogger
;
31 use Wikimedia\ScopedCallback
;
32 use Wikimedia\Timestamp\ConvertibleTimestamp
;
37 use InvalidArgumentException
;
38 use UnexpectedValueException
;
43 * Relational database abstraction object
48 abstract class Database
implements IDatabase
, IMaintainableDatabase
, LoggerAwareInterface
{
49 /** Number of times to re-try an operation in case of deadlock */
50 const DEADLOCK_TRIES
= 4;
51 /** Minimum time to wait before retry, in microseconds */
52 const DEADLOCK_DELAY_MIN
= 500000;
53 /** Maximum time to wait before retry */
54 const DEADLOCK_DELAY_MAX
= 1500000;
56 /** How long before it is worth doing a dummy query to test the connection */
58 const PING_QUERY
= 'SELECT 1 AS ping';
60 const TINY_WRITE_SEC
= 0.010;
61 const SLOW_WRITE_SEC
= 0.500;
62 const SMALL_WRITE_ROWS
= 100;
64 /** @var string Lock granularity is on the level of the entire database */
65 const ATTR_DB_LEVEL_LOCKING
= 'db-level-locking';
66 /** @var string The SCHEMA keyword refers to a grouping of tables in a database */
67 const ATTR_SCHEMAS_AS_TABLE_GROUPS
= 'supports-schemas';
69 /** @var int New Database instance will not be connected yet when returned */
70 const NEW_UNCONNECTED
= 0;
71 /** @var int New Database instance will already be connected when returned */
72 const NEW_CONNECTED
= 1;
74 /** @var string The last SQL query attempted */
75 private $lastQuery = '';
76 /** @var float|bool UNIX timestamp of last write query */
77 private $lastWriteTime = false;
78 /** @var string|bool */
79 private $lastPhpError = false;
81 /** @var string Server that this instance is currently connected to */
83 /** @var string User that this instance is currently connected under the name of */
85 /** @var string Password used to establish the current connection */
87 /** @var array[] Map of (table => (dbname, schema, prefix) map) */
88 protected $tableAliases = [];
89 /** @var string[] Map of (index alias => index) */
90 protected $indexAliases = [];
91 /** @var bool Whether this PHP instance is for a CLI script */
93 /** @var string Agent name for query profiling */
95 /** @var array Parameters used by initConnection() to establish a connection */
96 protected $connectionParams = [];
97 /** @var BagOStuff APC cache */
99 /** @var LoggerInterface */
100 protected $connLogger;
101 /** @var LoggerInterface */
102 protected $queryLogger;
103 /** @var callable Error logging callback */
104 protected $errorLogger;
105 /** @var callable Deprecation logging callback */
106 protected $deprecationLogger;
108 /** @var object|resource|null Database connection */
109 protected $conn = null;
111 protected $opened = false;
113 /** @var array[] List of (callable, method name, atomic section id) */
114 protected $trxIdleCallbacks = [];
115 /** @var array[] List of (callable, method name, atomic section id) */
116 protected $trxPreCommitCallbacks = [];
117 /** @var array[] List of (callable, method name, atomic section id) */
118 protected $trxEndCallbacks = [];
119 /** @var callable[] Map of (name => callable) */
120 protected $trxRecurringCallbacks = [];
121 /** @var bool Whether to suppress triggering of transaction end callbacks */
122 protected $trxEndCallbacksSuppressed = false;
127 protected $lbInfo = [];
128 /** @var array|bool */
129 protected $schemaVars = false;
131 protected $sessionVars = [];
132 /** @var array|null */
133 protected $preparedArgs;
134 /** @var string|bool|null Stashed value of html_errors INI setting */
135 protected $htmlErrors;
137 protected $delimiter = ';';
138 /** @var DatabaseDomain */
139 protected $currentDomain;
140 /** @var integer|null Rows affected by the last query to query() or its CRUD wrappers */
141 protected $affectedRowCount;
144 * @var int Transaction status
146 protected $trxStatus = self
::STATUS_TRX_NONE
;
148 * @var Exception|null The last error that caused the status to become STATUS_TRX_ERROR
150 protected $trxStatusCause;
152 * @var array|null If wasKnownStatementRollbackError() prevented trxStatus from being set,
153 * the relevant details are stored here.
155 protected $trxStatusIgnoredCause;
157 * Either 1 if a transaction is active or 0 otherwise.
158 * The other Trx fields may not be meaningfull if this is 0.
162 protected $trxLevel = 0;
164 * Either a short hexidecimal string if a transaction is active or ""
167 * @see Database::trxLevel
169 protected $trxShortId = '';
171 * The UNIX time that the transaction started. Callers can assume that if
172 * snapshot isolation is used, then the data is *at least* up to date to that
173 * point (possibly more up-to-date since the first SELECT defines the snapshot).
176 * @see Database::trxLevel
178 private $trxTimestamp = null;
179 /** @var float Lag estimate at the time of BEGIN */
180 private $trxReplicaLag = null;
182 * Remembers the function name given for starting the most recent transaction via begin().
183 * Used to provide additional context for error reporting.
186 * @see Database::trxLevel
188 private $trxFname = null;
190 * Record if possible write queries were done in the last transaction started
193 * @see Database::trxLevel
195 private $trxDoneWrites = false;
197 * Record if the current transaction was started implicitly due to DBO_TRX being set.
200 * @see Database::trxLevel
202 private $trxAutomatic = false;
204 * Counter for atomic savepoint identifiers. Reset when a new transaction begins.
208 private $trxAtomicCounter = 0;
210 * Array of levels of atomicity within transactions
212 * @var array List of (name, unique ID, savepoint ID)
214 private $trxAtomicLevels = [];
216 * Record if the current transaction was started implicitly by Database::startAtomic
220 private $trxAutomaticAtomic = false;
222 * Track the write query callers of the current transaction
226 private $trxWriteCallers = [];
228 * @var float Seconds spent in write queries for the current transaction
230 private $trxWriteDuration = 0.0;
232 * @var int Number of write queries for the current transaction
234 private $trxWriteQueryCount = 0;
236 * @var int Number of rows affected by write queries for the current transaction
238 private $trxWriteAffectedRows = 0;
240 * @var float Like trxWriteQueryCount but excludes lock-bound, easy to replicate, queries
242 private $trxWriteAdjDuration = 0.0;
244 * @var int Number of write queries counted in trxWriteAdjDuration
246 private $trxWriteAdjQueryCount = 0;
248 * @var float RTT time estimate
250 private $rttEstimate = 0.0;
252 /** @var array Map of (name => 1) for locks obtained via lock() */
253 private $namedLocksHeld = [];
254 /** @var array Map of (table name => 1) for TEMPORARY tables */
255 protected $sessionTempTables = [];
257 /** @var IDatabase|null Lazy handle to the master DB this server replicates from */
258 private $lazyMasterHandle;
260 /** @var float UNIX timestamp */
261 protected $lastPing = 0.0;
263 /** @var int[] Prior flags member variable values */
264 private $priorFlags = [];
266 /** @var callable|null */
268 /** @var TransactionProfiler */
269 protected $trxProfiler;
272 protected $nonNativeInsertSelectBatchSize = 10000;
274 /** @var string Idiom used when a cancelable atomic section started the transaction */
275 private static $NOT_APPLICABLE = 'n/a';
276 /** @var string Prefix to the atomic section counter used to make savepoint IDs */
277 private static $SAVEPOINT_PREFIX = 'wikimedia_rdbms_atomic';
279 /** @var int Transaction is in a error state requiring a full or savepoint rollback */
280 const STATUS_TRX_ERROR
= 1;
281 /** @var int Transaction is active and in a normal state */
282 const STATUS_TRX_OK
= 2;
283 /** @var int No transaction is active */
284 const STATUS_TRX_NONE
= 3;
286 /** @var int Writes to this temporary table do not affect lastDoneWrites() */
287 const TEMP_NORMAL
= 1;
288 /** @var int Writes to this temporary table effect lastDoneWrites() */
289 const TEMP_PSEUDO_PERMANENT
= 2;
292 * @note exceptions for missing libraries/drivers should be thrown in initConnection()
293 * @param array $params Parameters passed from Database::factory()
295 protected function __construct( array $params ) {
296 foreach ( [ 'host', 'user', 'password', 'dbname', 'schema', 'tablePrefix' ] as $name ) {
297 $this->connectionParams
[$name] = $params[$name];
300 $this->cliMode
= $params['cliMode'];
301 // Agent name is added to SQL queries in a comment, so make sure it can't break out
302 $this->agent
= str_replace( '/', '-', $params['agent'] );
304 $this->flags
= $params['flags'];
305 if ( $this->flags
& self
::DBO_DEFAULT
) {
306 if ( $this->cliMode
) {
307 $this->flags
&= ~self
::DBO_TRX
;
309 $this->flags |
= self
::DBO_TRX
;
312 // Disregard deprecated DBO_IGNORE flag (T189999)
313 $this->flags
&= ~self
::DBO_IGNORE
;
315 $this->sessionVars
= $params['variables'];
317 $this->srvCache
= $params['srvCache'] ??
new HashBagOStuff();
319 $this->profiler
= is_callable( $params['profiler'] ) ?
$params['profiler'] : null;
320 $this->trxProfiler
= $params['trxProfiler'];
321 $this->connLogger
= $params['connLogger'];
322 $this->queryLogger
= $params['queryLogger'];
323 $this->errorLogger
= $params['errorLogger'];
324 $this->deprecationLogger
= $params['deprecationLogger'];
326 if ( isset( $params['nonNativeInsertSelectBatchSize'] ) ) {
327 $this->nonNativeInsertSelectBatchSize
= $params['nonNativeInsertSelectBatchSize'];
330 // Set initial dummy domain until open() sets the final DB/prefix
331 $this->currentDomain
= new DatabaseDomain(
332 $params['dbname'] != '' ?
$params['dbname'] : null,
333 $params['schema'] != '' ?
$params['schema'] : null,
334 $params['tablePrefix']
339 * Initialize the connection to the database over the wire (or to local files)
341 * @throws LogicException
342 * @throws InvalidArgumentException
343 * @throws DBConnectionError
346 final public function initConnection() {
347 if ( $this->isOpen() ) {
348 throw new LogicException( __METHOD__
. ': already connected.' );
350 // Establish the connection
351 $this->doInitConnection();
355 * Actually connect to the database over the wire (or to local files)
357 * @throws InvalidArgumentException
358 * @throws DBConnectionError
361 protected function doInitConnection() {
362 if ( strlen( $this->connectionParams
['user'] ) ) {
364 $this->connectionParams
['host'],
365 $this->connectionParams
['user'],
366 $this->connectionParams
['password'],
367 $this->connectionParams
['dbname'],
368 $this->connectionParams
['schema'],
369 $this->connectionParams
['tablePrefix']
372 throw new InvalidArgumentException( "No database user provided." );
377 * Open a new connection to the database (closing any existing one)
379 * @param string $server Database server host
380 * @param string $user Database user name
381 * @param string $password Database user password
382 * @param string $dbName Database name
383 * @param string|null $schema Database schema name
384 * @param string $tablePrefix Table prefix
386 * @throws DBConnectionError
388 abstract protected function open( $server, $user, $password, $dbName, $schema, $tablePrefix );
391 * Construct a Database subclass instance given a database type and parameters
393 * This also connects to the database immediately upon object construction
395 * @param string $dbType A possible DB type (sqlite, mysql, postgres,...)
396 * @param array $p Parameter map with keys:
397 * - host : The hostname of the DB server
398 * - user : The name of the database user the client operates under
399 * - password : The password for the database user
400 * - dbname : The name of the database to use where queries do not specify one.
401 * The database must exist or an error might be thrown. Setting this to the empty string
402 * will avoid any such errors and make the handle have no implicit database scope. This is
403 * useful for queries like SHOW STATUS, CREATE DATABASE, or DROP DATABASE. Note that a
404 * "database" in Postgres is rougly equivalent to an entire MySQL server. This the domain
405 * in which user names and such are defined, e.g. users are database-specific in Postgres.
406 * - schema : The database schema to use (if supported). A "schema" in Postgres is roughly
407 * equivalent to a "database" in MySQL. Note that MySQL and SQLite do not use schemas.
408 * - tablePrefix : Optional table prefix that is implicitly added on to all table names
409 * recognized in queries. This can be used in place of schemas for handle site farms.
410 * - flags : Optional bitfield of DBO_* constants that define connection, protocol,
411 * buffering, and transaction behavior. It is STRONGLY adviced to leave the DBO_DEFAULT
412 * flag in place UNLESS this this database simply acts as a key/value store.
413 * - driver: Optional name of a specific DB client driver. For MySQL, there is only the
414 * 'mysqli' driver; the old one 'mysql' has been removed.
415 * - variables: Optional map of session variables to set after connecting. This can be
416 * used to adjust lock timeouts or encoding modes and the like.
417 * - connLogger: Optional PSR-3 logger interface instance.
418 * - queryLogger: Optional PSR-3 logger interface instance.
419 * - profiler : Optional callback that takes a section name argument and returns
420 * a ScopedCallback instance that ends the profile section in its destructor.
421 * These will be called in query(), using a simplified version of the SQL that
422 * also includes the agent as a SQL comment.
423 * - trxProfiler: Optional TransactionProfiler instance.
424 * - errorLogger: Optional callback that takes an Exception and logs it.
425 * - deprecationLogger: Optional callback that takes a string and logs it.
426 * - cliMode: Whether to consider the execution context that of a CLI script.
427 * - agent: Optional name used to identify the end-user in query profiling/logging.
428 * - srvCache: Optional BagOStuff instance to an APC-style cache.
429 * - nonNativeInsertSelectBatchSize: Optional batch size for non-native INSERT SELECT emulation.
430 * @param int $connect One of the class constants (NEW_CONNECTED, NEW_UNCONNECTED) [optional]
431 * @return Database|null If the database driver or extension cannot be found
432 * @throws InvalidArgumentException If the database driver or extension cannot be found
435 final public static function factory( $dbType, $p = [], $connect = self
::NEW_CONNECTED
) {
436 $class = self
::getClass( $dbType, $p['driver'] ??
null );
438 if ( class_exists( $class ) && is_subclass_of( $class, IDatabase
::class ) ) {
439 // Resolve some defaults for b/c
440 $p['host'] = $p['host'] ??
false;
441 $p['user'] = $p['user'] ??
false;
442 $p['password'] = $p['password'] ??
false;
443 $p['dbname'] = $p['dbname'] ??
false;
444 $p['flags'] = $p['flags'] ??
0;
445 $p['variables'] = $p['variables'] ??
[];
446 $p['tablePrefix'] = $p['tablePrefix'] ??
'';
447 $p['schema'] = $p['schema'] ??
null;
448 $p['cliMode'] = $p['cliMode'] ??
( PHP_SAPI
=== 'cli' || PHP_SAPI
=== 'phpdbg' );
449 $p['agent'] = $p['agent'] ??
'';
450 if ( !isset( $p['connLogger'] ) ) {
451 $p['connLogger'] = new NullLogger();
453 if ( !isset( $p['queryLogger'] ) ) {
454 $p['queryLogger'] = new NullLogger();
456 $p['profiler'] = $p['profiler'] ??
null;
457 if ( !isset( $p['trxProfiler'] ) ) {
458 $p['trxProfiler'] = new TransactionProfiler();
460 if ( !isset( $p['errorLogger'] ) ) {
461 $p['errorLogger'] = function ( Exception
$e ) {
462 trigger_error( get_class( $e ) . ': ' . $e->getMessage(), E_USER_WARNING
);
465 if ( !isset( $p['deprecationLogger'] ) ) {
466 $p['deprecationLogger'] = function ( $msg ) {
467 trigger_error( $msg, E_USER_DEPRECATED
);
471 /** @var Database $conn */
472 $conn = new $class( $p );
473 if ( $connect == self
::NEW_CONNECTED
) {
474 $conn->initConnection();
484 * @param string $dbType A possible DB type (sqlite, mysql, postgres,...)
485 * @param string|null $driver Optional name of a specific DB client driver
486 * @return array Map of (Database::ATTR_* constant => value) for all such constants
487 * @throws InvalidArgumentException
490 final public static function attributesFromType( $dbType, $driver = null ) {
492 self
::ATTR_DB_LEVEL_LOCKING
=> false,
493 self
::ATTR_SCHEMAS_AS_TABLE_GROUPS
=> false
496 $class = self
::getClass( $dbType, $driver );
498 return call_user_func( [ $class, 'getAttributes' ] ) +
$defaults;
502 * @param string $dbType A possible DB type (sqlite, mysql, postgres,...)
503 * @param string|null $driver Optional name of a specific DB client driver
504 * @return string Database subclass name to use
505 * @throws InvalidArgumentException
507 private static function getClass( $dbType, $driver = null ) {
508 // For database types with built-in support, the below maps type to IDatabase
509 // implementations. For types with multipe driver implementations (PHP extensions),
510 // an array can be used, keyed by extension name. In case of an array, the
511 // optional 'driver' parameter can be used to force a specific driver. Otherwise,
512 // we auto-detect the first available driver. For types without built-in support,
513 // an class named "Database<Type>" us used, eg. DatabaseFoo for type 'foo'.
514 static $builtinTypes = [
515 'mssql' => DatabaseMssql
::class,
516 'mysql' => [ 'mysqli' => DatabaseMysqli
::class ],
517 'sqlite' => DatabaseSqlite
::class,
518 'postgres' => DatabasePostgres
::class,
521 $dbType = strtolower( $dbType );
524 if ( isset( $builtinTypes[$dbType] ) ) {
525 $possibleDrivers = $builtinTypes[$dbType];
526 if ( is_string( $possibleDrivers ) ) {
527 $class = $possibleDrivers;
528 } elseif ( (string)$driver !== '' ) {
529 if ( !isset( $possibleDrivers[$driver] ) ) {
530 throw new InvalidArgumentException( __METHOD__
.
531 " type '$dbType' does not support driver '{$driver}'" );
534 $class = $possibleDrivers[$driver];
536 foreach ( $possibleDrivers as $posDriver => $possibleClass ) {
537 if ( extension_loaded( $posDriver ) ) {
538 $class = $possibleClass;
544 $class = 'Database' . ucfirst( $dbType );
547 if ( $class === false ) {
548 throw new InvalidArgumentException( __METHOD__
.
549 " no viable database extension found for type '$dbType'" );
556 * @return array Map of (Database::ATTR_* constant => value
559 protected static function getAttributes() {
564 * Set the PSR-3 logger interface to use for query logging. (The logger
565 * interfaces for connection logging and error logging can be set with the
568 * @param LoggerInterface $logger
570 public function setLogger( LoggerInterface
$logger ) {
571 $this->queryLogger
= $logger;
574 public function getServerInfo() {
575 return $this->getServerVersion();
578 public function bufferResults( $buffer = null ) {
579 $res = !$this->getFlag( self
::DBO_NOBUFFER
);
580 if ( $buffer !== null ) {
582 ?
$this->clearFlag( self
::DBO_NOBUFFER
)
583 : $this->setFlag( self
::DBO_NOBUFFER
);
589 public function trxLevel() {
590 return $this->trxLevel
;
593 public function trxTimestamp() {
594 return $this->trxLevel ?
$this->trxTimestamp
: null;
598 * @return int One of the STATUS_TRX_* class constants
601 public function trxStatus() {
602 return $this->trxStatus
;
605 public function tablePrefix( $prefix = null ) {
606 $old = $this->currentDomain
->getTablePrefix();
607 if ( $prefix !== null ) {
608 $this->currentDomain
= new DatabaseDomain(
609 $this->currentDomain
->getDatabase(),
610 $this->currentDomain
->getSchema(),
618 public function dbSchema( $schema = null ) {
619 if ( strlen( $schema ) && $this->getDBname() === null ) {
620 throw new DBUnexpectedError( $this, "Cannot set schema to '$schema'; no database set." );
623 $old = $this->currentDomain
->getSchema();
624 if ( $schema !== null ) {
625 $this->currentDomain
= new DatabaseDomain(
626 $this->currentDomain
->getDatabase(),
627 // DatabaseDomain uses null for unspecified schemas
628 strlen( $schema ) ?
$schema : null,
629 $this->currentDomain
->getTablePrefix()
637 * @return string Schema to use to qualify relations in queries
639 protected function relationSchemaQualifier() {
640 return $this->dbSchema();
643 public function getLBInfo( $name = null ) {
644 if ( is_null( $name ) ) {
645 return $this->lbInfo
;
648 if ( array_key_exists( $name, $this->lbInfo
) ) {
649 return $this->lbInfo
[$name];
655 public function setLBInfo( $name, $value = null ) {
656 if ( is_null( $value ) ) {
657 $this->lbInfo
= $name;
659 $this->lbInfo
[$name] = $value;
663 public function setLazyMasterHandle( IDatabase
$conn ) {
664 $this->lazyMasterHandle
= $conn;
668 * @return IDatabase|null
669 * @see setLazyMasterHandle()
672 protected function getLazyMasterHandle() {
673 return $this->lazyMasterHandle
;
676 public function implicitGroupby() {
680 public function implicitOrderby() {
684 public function lastQuery() {
685 return $this->lastQuery
;
688 public function doneWrites() {
689 return (bool)$this->lastWriteTime
;
692 public function lastDoneWrites() {
693 return $this->lastWriteTime ?
: false;
696 public function writesPending() {
697 return $this->trxLevel
&& $this->trxDoneWrites
;
700 public function writesOrCallbacksPending() {
701 return $this->trxLevel
&& (
702 $this->trxDoneWrites ||
703 $this->trxIdleCallbacks ||
704 $this->trxPreCommitCallbacks ||
705 $this->trxEndCallbacks
709 public function preCommitCallbacksPending() {
710 return $this->trxLevel
&& $this->trxPreCommitCallbacks
;
714 * @return string|null
716 final protected function getTransactionRoundId() {
717 // If transaction round participation is enabled, see if one is active
718 if ( $this->getFlag( self
::DBO_TRX
) ) {
719 $id = $this->getLBInfo( 'trxRoundId' );
721 return is_string( $id ) ?
$id : null;
727 public function pendingWriteQueryDuration( $type = self
::ESTIMATE_TOTAL
) {
728 if ( !$this->trxLevel
) {
730 } elseif ( !$this->trxDoneWrites
) {
735 case self
::ESTIMATE_DB_APPLY
:
736 return $this->pingAndCalculateLastTrxApplyTime();
737 default: // everything
738 return $this->trxWriteDuration
;
743 * @return float Time to apply writes to replicas based on trxWrite* fields
745 private function pingAndCalculateLastTrxApplyTime() {
748 $rttAdjTotal = $this->trxWriteAdjQueryCount
* $rtt;
749 $applyTime = max( $this->trxWriteAdjDuration
- $rttAdjTotal, 0 );
750 // For omitted queries, make them count as something at least
751 $omitted = $this->trxWriteQueryCount
- $this->trxWriteAdjQueryCount
;
752 $applyTime +
= self
::TINY_WRITE_SEC
* $omitted;
757 public function pendingWriteCallers() {
758 return $this->trxLevel ?
$this->trxWriteCallers
: [];
761 public function pendingWriteRowsAffected() {
762 return $this->trxWriteAffectedRows
;
766 * List the methods that have write queries or callbacks for the current transaction
768 * This method should not be used outside of Database/LoadBalancer
773 public function pendingWriteAndCallbackCallers() {
774 $fnames = $this->pendingWriteCallers();
776 $this->trxIdleCallbacks
,
777 $this->trxPreCommitCallbacks
,
778 $this->trxEndCallbacks
780 foreach ( $callbacks as $callback ) {
781 $fnames[] = $callback[1];
791 private function flatAtomicSectionList() {
792 return array_reduce( $this->trxAtomicLevels
, function ( $accum, $v ) {
793 return $accum === null ?
$v[0] : "$accum, " . $v[0];
797 public function isOpen() {
798 return $this->opened
;
801 public function setFlag( $flag, $remember = self
::REMEMBER_NOTHING
) {
802 if ( ( $flag & self
::DBO_IGNORE
) ) {
803 throw new UnexpectedValueException( "Modifying DBO_IGNORE is not allowed." );
806 if ( $remember === self
::REMEMBER_PRIOR
) {
807 array_push( $this->priorFlags
, $this->flags
);
809 $this->flags |
= $flag;
812 public function clearFlag( $flag, $remember = self
::REMEMBER_NOTHING
) {
813 if ( ( $flag & self
::DBO_IGNORE
) ) {
814 throw new UnexpectedValueException( "Modifying DBO_IGNORE is not allowed." );
817 if ( $remember === self
::REMEMBER_PRIOR
) {
818 array_push( $this->priorFlags
, $this->flags
);
820 $this->flags
&= ~
$flag;
823 public function restoreFlags( $state = self
::RESTORE_PRIOR
) {
824 if ( !$this->priorFlags
) {
828 if ( $state === self
::RESTORE_INITIAL
) {
829 $this->flags
= reset( $this->priorFlags
);
830 $this->priorFlags
= [];
832 $this->flags
= array_pop( $this->priorFlags
);
836 public function getFlag( $flag ) {
837 return (bool)( $this->flags
& $flag );
841 * @param string $name Class field name
843 * @deprecated Since 1.28
845 public function getProperty( $name ) {
849 public function getDomainID() {
850 return $this->currentDomain
->getId();
853 final public function getWikiID() {
854 return $this->getDomainID();
858 * Get information about an index into an object
859 * @param string $table Table name
860 * @param string $index Index name
861 * @param string $fname Calling function name
862 * @return mixed Database-specific index description class or false if the index does not exist
864 abstract function indexInfo( $table, $index, $fname = __METHOD__
);
867 * Wrapper for addslashes()
869 * @param string $s String to be slashed.
870 * @return string Slashed string.
872 abstract function strencode( $s );
875 * Set a custom error handler for logging errors during database connection
877 protected function installErrorHandler() {
878 $this->lastPhpError
= false;
879 $this->htmlErrors
= ini_set( 'html_errors', '0' );
880 set_error_handler( [ $this, 'connectionErrorLogger' ] );
884 * Restore the previous error handler and return the last PHP error for this DB
886 * @return bool|string
888 protected function restoreErrorHandler() {
889 restore_error_handler();
890 if ( $this->htmlErrors
!== false ) {
891 ini_set( 'html_errors', $this->htmlErrors
);
894 return $this->getLastPHPError();
898 * @return string|bool Last PHP error for this DB (typically connection errors)
900 protected function getLastPHPError() {
901 if ( $this->lastPhpError
) {
902 $error = preg_replace( '!\[<a.*</a>\]!', '', $this->lastPhpError
);
903 $error = preg_replace( '!^.*?:\s?(.*)$!', '$1', $error );
912 * Error handler for logging errors during database connection
913 * This method should not be used outside of Database classes
916 * @param string $errstr
918 public function connectionErrorLogger( $errno, $errstr ) {
919 $this->lastPhpError
= $errstr;
923 * Create a log context to pass to PSR-3 logger functions.
925 * @param array $extras Additional data to add to context
928 protected function getLogContext( array $extras = [] ) {
931 'db_server' => $this->server
,
932 'db_name' => $this->getDBname(),
933 'db_user' => $this->user
,
939 final public function close() {
940 $exception = null; // error to throw after disconnecting
942 $wasOpen = $this->opened
;
943 // This should mostly do nothing if the connection is already closed
945 // Roll back any dangling transaction first
946 if ( $this->trxLevel
) {
947 if ( $this->trxAtomicLevels
) {
948 // Cannot let incomplete atomic sections be committed
949 $levels = $this->flatAtomicSectionList();
950 $exception = new DBUnexpectedError(
952 __METHOD__
. ": atomic sections $levels are still open."
954 } elseif ( $this->trxAutomatic
) {
955 // Only the connection manager can commit non-empty DBO_TRX transactions
956 // (empty ones we can silently roll back)
957 if ( $this->writesOrCallbacksPending() ) {
958 $exception = new DBUnexpectedError(
961 ": mass commit/rollback of peer transaction required (DBO_TRX set)."
965 // Manual transactions should have been committed or rolled
966 // back, even if empty.
967 $exception = new DBUnexpectedError(
969 __METHOD__
. ": transaction is still open (from {$this->trxFname})."
973 if ( $this->trxEndCallbacksSuppressed
) {
974 $exception = $exception ?
: new DBUnexpectedError(
976 __METHOD__
. ': callbacks are suppressed; cannot properly commit.'
980 // Rollback the changes and run any callbacks as needed
981 $this->rollback( __METHOD__
, self
::FLUSHING_INTERNAL
);
984 // Close the actual connection in the binding handle
985 $closed = $this->closeConnection();
987 $closed = true; // already closed; nothing to do
991 $this->opened
= false;
993 // Throw any unexpected errors after having disconnected
994 if ( $exception instanceof Exception
) {
998 // Note that various subclasses call close() at the start of open(), which itself is
999 // called by replaceLostConnection(). In that case, just because onTransactionResolution()
1000 // callbacks are pending does not mean that an exception should be thrown. Rather, they
1001 // will be executed after the reconnection step.
1003 // Sanity check that no callbacks are dangling
1004 $fnames = $this->pendingWriteAndCallbackCallers();
1006 throw new RuntimeException(
1007 "Transaction callbacks are still pending:\n" . implode( ', ', $fnames )
1016 * Make sure there is an open connection handle (alive or not) as a sanity check
1018 * This guards against fatal errors to the binding handle not being defined
1019 * in cases where open() was never called or close() was already called
1021 * @throws DBUnexpectedError
1023 final protected function assertHasConnectionHandle() {
1024 if ( !$this->isOpen() ) {
1025 throw new DBUnexpectedError( $this, "DB connection was already closed." );
1030 * Make sure that this server is not marked as a replica nor read-only as a sanity check
1032 * @throws DBReadOnlyRoleError
1033 * @throws DBReadOnlyError
1035 protected function assertIsWritableMaster() {
1036 if ( $this->getLBInfo( 'replica' ) === true ) {
1037 throw new DBReadOnlyRoleError(
1039 'Write operations are not allowed on replica database connections.'
1042 $reason = $this->getReadOnlyReason();
1043 if ( $reason !== false ) {
1044 throw new DBReadOnlyError( $this, "Database is read-only: $reason" );
1049 * Closes underlying database connection
1051 * @return bool Whether connection was closed successfully
1053 abstract protected function closeConnection();
1056 * @deprecated since 1.32
1057 * @param string $error Fallback message, if none is given by DB
1058 * @throws DBConnectionError
1060 public function reportConnectionError( $error = 'Unknown error' ) {
1061 call_user_func( $this->deprecationLogger
, 'Use of ' . __METHOD__
. ' is deprecated.' );
1062 throw new DBConnectionError( $this, $this->lastError() ?
: $error );
1066 * Run a query and return a DBMS-dependent wrapper or boolean
1068 * This is meant to handle the basic command of actually sending a query to the
1069 * server via the driver. No implicit transaction, reconnection, nor retry logic
1070 * should happen here. The higher level query() method is designed to handle those
1071 * sorts of concerns. This method should not trigger such higher level methods.
1073 * The lastError() and lastErrno() methods should meaningfully reflect what error,
1074 * if any, occured during the last call to this method. Methods like executeQuery(),
1075 * query(), select(), insert(), update(), delete(), and upsert() implement their calls
1076 * to doQuery() such that an immediately subsequent call to lastError()/lastErrno()
1077 * meaningfully reflects any error that occured during that public query method call.
1079 * For SELECT queries, this returns either:
1080 * - a) A driver-specific value/resource, only on success. This can be iterated
1081 * over by calling fetchObject()/fetchRow() until there are no more rows.
1082 * Alternatively, the result can be passed to resultObject() to obtain a
1083 * ResultWrapper instance which can then be iterated over via "foreach".
1084 * - b) False, on any query failure
1086 * For non-SELECT queries, this returns either:
1087 * - a) A driver-specific value/resource, only on success
1088 * - b) True, only on success (e.g. no meaningful result other than "OK")
1089 * - c) False, on any query failure
1091 * @param string $sql SQL query
1092 * @return mixed|bool An object, resource, or true on success; false on failure
1094 abstract protected function doQuery( $sql );
1097 * Determine whether a query writes to the DB. When in doubt, this returns true.
1101 * - Subsequent web requests should not need to wait for replication from
1102 * the master position seen by this web request, unless this request made
1103 * changes to the master. This is handled by ChronologyProtector by checking
1104 * doneWrites() at the end of the request. doneWrites() returns true if any
1105 * query set lastWriteTime; which query() does based on isWriteQuery().
1107 * - Reject write queries to replica DBs, in query().
1109 * @param string $sql
1112 protected function isWriteQuery( $sql ) {
1113 // BEGIN and COMMIT queries are considered read queries here.
1114 // Database backends and drivers (MySQL, MariaDB, php-mysqli) generally
1115 // treat these as write queries, in that their results have "affected rows"
1116 // as meta data as from writes, instead of "num rows" as from reads.
1117 // But, we treat them as read queries because when reading data (from
1118 // either replica or master) we use transactions to enable repeatable-read
1119 // snapshots, which ensures we get consistent results from the same snapshot
1120 // for all queries within a request. Use cases:
1121 // - Treating these as writes would trigger ChronologyProtector (see method doc).
1122 // - We use this method to reject writes to replicas, but we need to allow
1123 // use of transactions on replicas for read snapshots. This is fine given
1124 // that transactions by themselves don't make changes, only actual writes
1125 // within the transaction matter, which we still detect.
1127 '/^(?:SELECT|BEGIN|ROLLBACK|COMMIT|SAVEPOINT|RELEASE|SET|SHOW|EXPLAIN|USE|\(SELECT)\b/i',
1133 * @param string $sql
1134 * @return string|null
1136 protected function getQueryVerb( $sql ) {
1137 return preg_match( '/^\s*([a-z]+)/i', $sql, $m ) ?
strtoupper( $m[1] ) : null;
1141 * Determine whether a SQL statement is sensitive to isolation level.
1143 * A SQL statement is considered transactable if its result could vary
1144 * depending on the transaction isolation level. Operational commands
1145 * such as 'SET' and 'SHOW' are not considered to be transactable.
1147 * Main purpose: Used by query() to decide whether to begin a transaction
1148 * before the current query (in DBO_TRX mode, on by default).
1150 * @param string $sql
1153 protected function isTransactableQuery( $sql ) {
1155 $this->getQueryVerb( $sql ),
1156 [ 'BEGIN', 'ROLLBACK', 'COMMIT', 'SET', 'SHOW', 'CREATE', 'ALTER', 'USE' ],
1162 * @param string $sql A SQL query
1163 * @param bool $pseudoPermanent Treat any table from CREATE TEMPORARY as pseudo-permanent
1164 * @return int|null A self::TEMP_* constant for temp table operations or null otherwise
1166 protected function registerTempTableWrite( $sql, $pseudoPermanent ) {
1167 static $qt = '[`"\']?(\w+)[`"\']?'; // quoted table
1170 '/^CREATE\s+TEMPORARY\s+TABLE\s+(?:IF\s+NOT\s+EXISTS\s+)?' . $qt . '/i',
1174 $type = $pseudoPermanent ? self
::TEMP_PSEUDO_PERMANENT
: self
::TEMP_NORMAL
;
1175 $this->sessionTempTables
[$matches[1]] = $type;
1178 } elseif ( preg_match(
1179 '/^DROP\s+(?:TEMPORARY\s+)?TABLE\s+(?:IF\s+EXISTS\s+)?' . $qt . '/i',
1183 $type = $this->sessionTempTables
[$matches[1]] ??
null;
1184 unset( $this->sessionTempTables
[$matches[1]] );
1187 } elseif ( preg_match(
1188 '/^TRUNCATE\s+(?:TEMPORARY\s+)?TABLE\s+(?:IF\s+EXISTS\s+)?' . $qt . '/i',
1192 return $this->sessionTempTables
[$matches[1]] ??
null;
1193 } elseif ( preg_match(
1194 '/^(?:(?:INSERT|REPLACE)\s+(?:\w+\s+)?INTO|UPDATE|DELETE\s+FROM)\s+' . $qt . '/i',
1198 return $this->sessionTempTables
[$matches[1]] ??
null;
1204 public function query( $sql, $fname = __METHOD__
, $flags = 0 ) {
1205 $flags = (int)$flags; // b/c; this field used to be a bool
1206 // Sanity check that the SQL query is appropriate in the current context and is
1207 // allowed for an outside caller (e.g. does not break transaction/session tracking).
1208 $this->assertQueryIsCurrentlyAllowed( $sql, $fname );
1210 // Send the query to the server and fetch any corresponding errors
1211 list( $ret, $err, $errno, $unignorable ) = $this->executeQuery( $sql, $fname, $flags );
1212 if ( $ret === false ) {
1213 $ignoreErrors = $this->hasFlags( $flags, self
::QUERY_SILENCE_ERRORS
);
1214 // Throw an error unless both the ignore flag was set and a rollback is not needed
1215 $this->reportQueryError( $err, $errno, $sql, $fname, $ignoreErrors && !$unignorable );
1218 return $this->resultObject( $ret );
1222 * Execute a query, retrying it if there is a recoverable connection loss
1224 * This is similar to query() except:
1225 * - It does not prevent all non-ROLLBACK queries if there is a corrupted transaction
1226 * - It does not disallow raw queries that are supposed to use dedicated IDatabase methods
1227 * - It does not throw exceptions for common error cases
1229 * This is meant for internal use with Database subclasses.
1231 * @param string $sql Original SQL query
1232 * @param string $fname Name of the calling function
1233 * @param int $flags Bitfield of class QUERY_* constants
1234 * @return array An n-tuple of:
1235 * - mixed|bool: An object, resource, or true on success; false on failure
1236 * - string: The result of calling lastError()
1237 * - int: The result of calling lastErrno()
1238 * - bool: Whether a rollback is needed to allow future non-rollback queries
1239 * @throws DBUnexpectedError
1241 final protected function executeQuery( $sql, $fname, $flags ) {
1242 $this->assertHasConnectionHandle();
1244 $priorTransaction = $this->trxLevel
;
1246 if ( $this->isWriteQuery( $sql ) ) {
1247 # In theory, non-persistent writes are allowed in read-only mode, but due to things
1248 # like https://bugs.mysql.com/bug.php?id=33669 that might not work anyway...
1249 $this->assertIsWritableMaster();
1250 # Do not treat temporary table writes as "meaningful writes" since they are only
1251 # visible to one session and are not permanent. Profile them as reads. Integration
1252 # tests can override this behavior via $flags.
1253 $pseudoPermanent = $this->hasFlags( $flags, self
::QUERY_PSEUDO_PERMANENT
);
1254 $tableType = $this->registerTempTableWrite( $sql, $pseudoPermanent );
1255 $isPermWrite = ( $tableType !== self
::TEMP_NORMAL
);
1256 # DBConnRef uses QUERY_REPLICA_ROLE to enforce the replica role for raw SQL queries
1257 if ( $isPermWrite && $this->hasFlags( $flags, self
::QUERY_REPLICA_ROLE
) ) {
1258 throw new DBReadOnlyRoleError( $this, "Cannot write; target role is DB_REPLICA" );
1261 $isPermWrite = false;
1264 // Add trace comment to the begin of the sql string, right after the operator.
1265 // Or, for one-word queries (like "BEGIN" or COMMIT") add it to the end (T44598)
1266 $commentedSql = preg_replace( '/\s|$/', " /* $fname {$this->agent} */ ", $sql, 1 );
1268 // Send the query to the server and fetch any corresponding errors
1269 list( $ret, $err, $errno, $recoverableSR, $recoverableCL, $reconnected ) =
1270 $this->executeQueryAttempt( $sql, $commentedSql, $isPermWrite, $fname, $flags );
1271 // Check if the query failed due to a recoverable connection loss
1272 if ( $ret === false && $recoverableCL && $reconnected ) {
1273 // Silently resend the query to the server since it is safe and possible
1274 list( $ret, $err, $errno, $recoverableSR, $recoverableCL ) =
1275 $this->executeQueryAttempt( $sql, $commentedSql, $isPermWrite, $fname, $flags );
1278 $corruptedTrx = false;
1280 if ( $ret === false ) {
1281 if ( $priorTransaction ) {
1282 if ( $recoverableSR ) {
1283 # We're ignoring an error that caused just the current query to be aborted.
1284 # But log the cause so we can log a deprecation notice if a caller actually
1286 $this->trxStatusIgnoredCause
= [ $err, $errno, $fname ];
1287 } elseif ( !$recoverableCL ) {
1288 # Either the query was aborted or all queries after BEGIN where aborted.
1289 # In the first case, the only options going forward are (a) ROLLBACK, or
1290 # (b) ROLLBACK TO SAVEPOINT (if one was set). If the later case, the only
1291 # option is ROLLBACK, since the snapshots would have been released.
1292 $corruptedTrx = true; // cannot recover
1293 $this->trxStatus
= self
::STATUS_TRX_ERROR
;
1294 $this->trxStatusCause
=
1295 $this->getQueryExceptionAndLog( $err, $errno, $sql, $fname );
1296 $this->trxStatusIgnoredCause
= null;
1301 return [ $ret, $err, $errno, $corruptedTrx ];
1305 * Wrapper for doQuery() that handles DBO_TRX, profiling, logging, affected row count
1306 * tracking, and reconnects (without retry) on query failure due to connection loss
1308 * @param string $sql Original SQL query
1309 * @param string $commentedSql SQL query with debugging/trace comment
1310 * @param bool $isPermWrite Whether the query is a (non-temporary table) write
1311 * @param string $fname Name of the calling function
1312 * @param int $flags Bitfield of class QUERY_* constants
1313 * @return array An n-tuple of:
1314 * - mixed|bool: An object, resource, or true on success; false on failure
1315 * - string: The result of calling lastError()
1316 * - int: The result of calling lastErrno()
1317 * - bool: Whether a statement rollback error occured
1318 * - bool: Whether a disconnect *both* happened *and* was recoverable
1319 * - bool: Whether a reconnection attempt was *both* made *and* succeeded
1320 * @throws DBUnexpectedError
1322 private function executeQueryAttempt( $sql, $commentedSql, $isPermWrite, $fname, $flags ) {
1323 $priorWritesPending = $this->writesOrCallbacksPending();
1325 if ( ( $flags & self
::QUERY_IGNORE_DBO_TRX
) == 0 ) {
1326 $this->beginIfImplied( $sql, $fname );
1329 // Keep track of whether the transaction has write queries pending
1330 if ( $isPermWrite ) {
1331 $this->lastWriteTime
= microtime( true );
1332 if ( $this->trxLevel
&& !$this->trxDoneWrites
) {
1333 $this->trxDoneWrites
= true;
1334 $this->trxProfiler
->transactionWritingIn(
1335 $this->server
, $this->getDomainID(), $this->trxShortId
);
1339 $prefix = !is_null( $this->getLBInfo( 'master' ) ) ?
'query-m: ' : 'query: ';
1340 $generalizedSql = new GeneralizedSql( $sql, $this->trxShortId
, $prefix );
1342 $startTime = microtime( true );
1343 $ps = $this->profiler
1344 ?
( $this->profiler
)( $generalizedSql->stringify() )
1346 $this->affectedRowCount
= null;
1347 $this->lastQuery
= $sql;
1348 $ret = $this->doQuery( $commentedSql );
1349 $lastError = $this->lastError();
1350 $lastErrno = $this->lastErrno();
1352 $this->affectedRowCount
= $this->affectedRows();
1353 unset( $ps ); // profile out (if set)
1354 $queryRuntime = max( microtime( true ) - $startTime, 0.0 );
1356 $recoverableSR = false; // recoverable statement rollback?
1357 $recoverableCL = false; // recoverable connection loss?
1358 $reconnected = false; // reconnection both attempted and succeeded?
1360 if ( $ret !== false ) {
1361 $this->lastPing
= $startTime;
1362 if ( $isPermWrite && $this->trxLevel
) {
1363 $this->updateTrxWriteQueryTime( $sql, $queryRuntime, $this->affectedRows() );
1364 $this->trxWriteCallers
[] = $fname;
1366 } elseif ( $this->wasConnectionError( $lastErrno ) ) {
1367 # Check if no meaningful session state was lost
1368 $recoverableCL = $this->canRecoverFromDisconnect( $sql, $priorWritesPending );
1369 # Update session state tracking and try to restore the connection
1370 $reconnected = $this->replaceLostConnection( __METHOD__
);
1372 # Check if only the last query was rolled back
1373 $recoverableSR = $this->wasKnownStatementRollbackError();
1376 if ( $sql === self
::PING_QUERY
) {
1377 $this->rttEstimate
= $queryRuntime;
1380 $this->trxProfiler
->recordQueryCompletion(
1384 $isPermWrite ?
$this->affectedRows() : $this->numRows( $ret )
1387 // Avoid the overhead of logging calls unless debug mode is enabled
1388 if ( $this->getFlag( self
::DBO_DEBUG
) ) {
1389 $this->queryLogger
->debug(
1390 "{method} [{runtime}s]: $sql",
1393 'db_host' => $this->getServer(),
1394 'domain' => $this->getDomainID(),
1395 'runtime' => round( $queryRuntime, 3 )
1400 return [ $ret, $lastError, $lastErrno, $recoverableSR, $recoverableCL, $reconnected ];
1404 * Start an implicit transaction if DBO_TRX is enabled and no transaction is active
1406 * @param string $sql
1407 * @param string $fname
1409 private function beginIfImplied( $sql, $fname ) {
1412 $this->getFlag( self
::DBO_TRX
) &&
1413 $this->isTransactableQuery( $sql )
1415 $this->begin( __METHOD__
. " ($fname)", self
::TRANSACTION_INTERNAL
);
1416 $this->trxAutomatic
= true;
1421 * Update the estimated run-time of a query, not counting large row lock times
1423 * LoadBalancer can be set to rollback transactions that will create huge replication
1424 * lag. It bases this estimate off of pendingWriteQueryDuration(). Certain simple
1425 * queries, like inserting a row can take a long time due to row locking. This method
1426 * uses some simple heuristics to discount those cases.
1428 * @param string $sql A SQL write query
1429 * @param float $runtime Total runtime, including RTT
1430 * @param int $affected Affected row count
1432 private function updateTrxWriteQueryTime( $sql, $runtime, $affected ) {
1433 // Whether this is indicative of replica DB runtime (except for RBR or ws_repl)
1434 $indicativeOfReplicaRuntime = true;
1435 if ( $runtime > self
::SLOW_WRITE_SEC
) {
1436 $verb = $this->getQueryVerb( $sql );
1437 // insert(), upsert(), replace() are fast unless bulky in size or blocked on locks
1438 if ( $verb === 'INSERT' ) {
1439 $indicativeOfReplicaRuntime = $this->affectedRows() > self
::SMALL_WRITE_ROWS
;
1440 } elseif ( $verb === 'REPLACE' ) {
1441 $indicativeOfReplicaRuntime = $this->affectedRows() > self
::SMALL_WRITE_ROWS
/ 2;
1445 $this->trxWriteDuration +
= $runtime;
1446 $this->trxWriteQueryCount +
= 1;
1447 $this->trxWriteAffectedRows +
= $affected;
1448 if ( $indicativeOfReplicaRuntime ) {
1449 $this->trxWriteAdjDuration +
= $runtime;
1450 $this->trxWriteAdjQueryCount +
= 1;
1455 * Error out if the DB is not in a valid state for a query via query()
1457 * @param string $sql
1458 * @param string $fname
1459 * @throws DBTransactionStateError
1461 private function assertQueryIsCurrentlyAllowed( $sql, $fname ) {
1462 $verb = $this->getQueryVerb( $sql );
1463 if ( $verb === 'USE' ) {
1464 throw new DBUnexpectedError( $this, "Got USE query; use selectDomain() instead." );
1467 if ( $verb === 'ROLLBACK' ) { // transaction/savepoint
1471 if ( $this->trxStatus
< self
::STATUS_TRX_OK
) {
1472 throw new DBTransactionStateError(
1474 "Cannot execute query from $fname while transaction status is ERROR.",
1476 $this->trxStatusCause
1478 } elseif ( $this->trxStatus
=== self
::STATUS_TRX_OK
&& $this->trxStatusIgnoredCause
) {
1479 list( $iLastError, $iLastErrno, $iFname ) = $this->trxStatusIgnoredCause
;
1480 call_user_func( $this->deprecationLogger
,
1481 "Caller from $fname ignored an error originally raised from $iFname: " .
1482 "[$iLastErrno] $iLastError"
1484 $this->trxStatusIgnoredCause
= null;
1488 public function assertNoOpenTransactions() {
1489 if ( $this->explicitTrxActive() ) {
1490 throw new DBTransactionError(
1492 "Explicit transaction still active. A caller may have caught an error. "
1493 . "Open transactions: " . $this->flatAtomicSectionList()
1499 * Determine whether it is safe to retry queries after a database connection is lost
1501 * @param string $sql SQL query
1502 * @param bool $priorWritesPending Whether there is a transaction open with
1503 * possible write queries or transaction pre-commit/idle callbacks
1504 * waiting on it to finish.
1505 * @return bool True if it is safe to retry the query, false otherwise
1507 private function canRecoverFromDisconnect( $sql, $priorWritesPending ) {
1508 # Transaction dropped; this can mean lost writes, or REPEATABLE-READ snapshots.
1509 # Dropped connections also mean that named locks are automatically released.
1510 # Only allow error suppression in autocommit mode or when the lost transaction
1511 # didn't matter anyway (aside from DBO_TRX snapshot loss).
1512 if ( $this->namedLocksHeld
) {
1513 return false; // possible critical section violation
1514 } elseif ( $this->sessionTempTables
) {
1515 return false; // tables might be queried latter
1516 } elseif ( $sql === 'COMMIT' ) {
1517 return !$priorWritesPending; // nothing written anyway? (T127428)
1518 } elseif ( $sql === 'ROLLBACK' ) {
1519 return true; // transaction lost...which is also what was requested :)
1520 } elseif ( $this->explicitTrxActive() ) {
1521 return false; // don't drop atomocity and explicit snapshots
1522 } elseif ( $priorWritesPending ) {
1523 return false; // prior writes lost from implicit transaction
1530 * Clean things up after session (and thus transaction) loss before reconnect
1532 private function handleSessionLossPreconnect() {
1533 // Clean up tracking of session-level things...
1534 // https://dev.mysql.com/doc/refman/5.7/en/implicit-commit.html
1535 // https://www.postgresql.org/docs/9.2/static/sql-createtable.html (ignoring ON COMMIT)
1536 $this->sessionTempTables
= [];
1537 // https://dev.mysql.com/doc/refman/5.7/en/miscellaneous-functions.html#function_get-lock
1538 // https://www.postgresql.org/docs/9.4/static/functions-admin.html#FUNCTIONS-ADVISORY-LOCKS
1539 $this->namedLocksHeld
= [];
1540 // Session loss implies transaction loss
1541 $this->trxLevel
= 0;
1542 $this->trxAtomicCounter
= 0;
1543 $this->trxIdleCallbacks
= []; // T67263; transaction already lost
1544 $this->trxPreCommitCallbacks
= []; // T67263; transaction already lost
1545 // @note: leave trxRecurringCallbacks in place
1546 if ( $this->trxDoneWrites
) {
1547 $this->trxProfiler
->transactionWritingOut(
1549 $this->getDomainID(),
1551 $this->pendingWriteQueryDuration( self
::ESTIMATE_TOTAL
),
1552 $this->trxWriteAffectedRows
1558 * Clean things up after session (and thus transaction) loss after reconnect
1560 private function handleSessionLossPostconnect() {
1562 // Handle callbacks in trxEndCallbacks, e.g. onTransactionResolution().
1563 // If callback suppression is set then the array will remain unhandled.
1564 $this->runOnTransactionIdleCallbacks( self
::TRIGGER_ROLLBACK
);
1565 } catch ( Exception
$ex ) {
1566 // Already logged; move on...
1569 // Handle callbacks in trxRecurringCallbacks, e.g. setTransactionListener()
1570 $this->runTransactionListenerCallbacks( self
::TRIGGER_ROLLBACK
);
1571 } catch ( Exception
$ex ) {
1572 // Already logged; move on...
1577 * Checks whether the cause of the error is detected to be a timeout.
1579 * It returns false by default, and not all engines support detecting this yet.
1580 * If this returns false, it will be treated as a generic query error.
1582 * @param string $error Error text
1583 * @param int $errno Error number
1586 protected function wasQueryTimeout( $error, $errno ) {
1591 * Report a query error. Log the error, and if neither the object ignore
1592 * flag nor the $ignoreErrors flag is set, throw a DBQueryError.
1594 * @param string $error
1596 * @param string $sql
1597 * @param string $fname
1598 * @param bool $ignore
1599 * @throws DBQueryError
1601 public function reportQueryError( $error, $errno, $sql, $fname, $ignore = false ) {
1603 $this->queryLogger
->debug( "SQL ERROR (ignored): $error\n" );
1605 $exception = $this->getQueryExceptionAndLog( $error, $errno, $sql, $fname );
1612 * @param string $error
1613 * @param string|int $errno
1614 * @param string $sql
1615 * @param string $fname
1618 private function getQueryExceptionAndLog( $error, $errno, $sql, $fname ) {
1619 $sql1line = mb_substr( str_replace( "\n", "\\n", $sql ), 0, 5 * 1024 );
1620 $this->queryLogger
->error(
1621 "{fname}\t{db_server}\t{errno}\t{error}\t{sql1line}",
1622 $this->getLogContext( [
1623 'method' => __METHOD__
,
1626 'sql1line' => $sql1line,
1628 'trace' => ( new RuntimeException() )->getTraceAsString()
1631 $this->queryLogger
->debug( "SQL ERROR: " . $error . "\n" );
1632 if ( $this->wasQueryTimeout( $error, $errno ) ) {
1633 $e = new DBQueryTimeoutError( $this, $error, $errno, $sql, $fname );
1634 } elseif ( $this->wasConnectionError( $errno ) ) {
1635 $e = new DBQueryDisconnectedError( $this, $error, $errno, $sql, $fname );
1637 $e = new DBQueryError( $this, $error, $errno, $sql, $fname );
1643 public function freeResult( $res ) {
1646 public function selectField(
1647 $table, $var, $cond = '', $fname = __METHOD__
, $options = [], $join_conds = []
1649 if ( $var === '*' ) { // sanity
1650 throw new DBUnexpectedError( $this, "Cannot use a * field: got '$var'" );
1653 if ( !is_array( $options ) ) {
1654 $options = [ $options ];
1657 $options['LIMIT'] = 1;
1659 $res = $this->select( $table, $var, $cond, $fname, $options, $join_conds );
1660 if ( $res === false ) {
1661 throw new DBUnexpectedError( $this, "Got false from select()" );
1664 $row = $this->fetchRow( $res );
1665 if ( $row === false ) {
1669 return reset( $row );
1672 public function selectFieldValues(
1673 $table, $var, $cond = '', $fname = __METHOD__
, $options = [], $join_conds = []
1675 if ( $var === '*' ) { // sanity
1676 throw new DBUnexpectedError( $this, "Cannot use a * field" );
1677 } elseif ( !is_string( $var ) ) { // sanity
1678 throw new DBUnexpectedError( $this, "Cannot use an array of fields" );
1681 if ( !is_array( $options ) ) {
1682 $options = [ $options ];
1685 $res = $this->select( $table, [ 'value' => $var ], $cond, $fname, $options, $join_conds );
1686 if ( $res === false ) {
1687 throw new DBUnexpectedError( $this, "Got false from select()" );
1691 foreach ( $res as $row ) {
1692 $values[] = $row->value
;
1699 * Returns an optional USE INDEX clause to go after the table, and a
1700 * string to go at the end of the query.
1702 * @param array $options Associative array of options to be turned into
1703 * an SQL query, valid keys are listed in the function.
1705 * @see Database::select()
1707 protected function makeSelectOptions( $options ) {
1708 $preLimitTail = $postLimitTail = '';
1713 foreach ( $options as $key => $option ) {
1714 if ( is_numeric( $key ) ) {
1715 $noKeyOptions[$option] = true;
1719 $preLimitTail .= $this->makeGroupByWithHaving( $options );
1721 $preLimitTail .= $this->makeOrderBy( $options );
1723 if ( isset( $noKeyOptions['FOR UPDATE'] ) ) {
1724 $postLimitTail .= ' FOR UPDATE';
1727 if ( isset( $noKeyOptions['LOCK IN SHARE MODE'] ) ) {
1728 $postLimitTail .= ' LOCK IN SHARE MODE';
1731 if ( isset( $noKeyOptions['DISTINCT'] ) ||
isset( $noKeyOptions['DISTINCTROW'] ) ) {
1732 $startOpts .= 'DISTINCT';
1735 # Various MySQL extensions
1736 if ( isset( $noKeyOptions['STRAIGHT_JOIN'] ) ) {
1737 $startOpts .= ' /*! STRAIGHT_JOIN */';
1740 if ( isset( $noKeyOptions['HIGH_PRIORITY'] ) ) {
1741 $startOpts .= ' HIGH_PRIORITY';
1744 if ( isset( $noKeyOptions['SQL_BIG_RESULT'] ) ) {
1745 $startOpts .= ' SQL_BIG_RESULT';
1748 if ( isset( $noKeyOptions['SQL_BUFFER_RESULT'] ) ) {
1749 $startOpts .= ' SQL_BUFFER_RESULT';
1752 if ( isset( $noKeyOptions['SQL_SMALL_RESULT'] ) ) {
1753 $startOpts .= ' SQL_SMALL_RESULT';
1756 if ( isset( $noKeyOptions['SQL_CALC_FOUND_ROWS'] ) ) {
1757 $startOpts .= ' SQL_CALC_FOUND_ROWS';
1760 if ( isset( $noKeyOptions['SQL_CACHE'] ) ) {
1761 $startOpts .= ' SQL_CACHE';
1764 if ( isset( $noKeyOptions['SQL_NO_CACHE'] ) ) {
1765 $startOpts .= ' SQL_NO_CACHE';
1768 if ( isset( $options['USE INDEX'] ) && is_string( $options['USE INDEX'] ) ) {
1769 $useIndex = $this->useIndexClause( $options['USE INDEX'] );
1773 if ( isset( $options['IGNORE INDEX'] ) && is_string( $options['IGNORE INDEX'] ) ) {
1774 $ignoreIndex = $this->ignoreIndexClause( $options['IGNORE INDEX'] );
1779 return [ $startOpts, $useIndex, $preLimitTail, $postLimitTail, $ignoreIndex ];
1783 * Returns an optional GROUP BY with an optional HAVING
1785 * @param array $options Associative array of options
1787 * @see Database::select()
1790 protected function makeGroupByWithHaving( $options ) {
1792 if ( isset( $options['GROUP BY'] ) ) {
1793 $gb = is_array( $options['GROUP BY'] )
1794 ?
implode( ',', $options['GROUP BY'] )
1795 : $options['GROUP BY'];
1796 $sql .= ' GROUP BY ' . $gb;
1798 if ( isset( $options['HAVING'] ) ) {
1799 $having = is_array( $options['HAVING'] )
1800 ?
$this->makeList( $options['HAVING'], self
::LIST_AND
)
1801 : $options['HAVING'];
1802 $sql .= ' HAVING ' . $having;
1809 * Returns an optional ORDER BY
1811 * @param array $options Associative array of options
1813 * @see Database::select()
1816 protected function makeOrderBy( $options ) {
1817 if ( isset( $options['ORDER BY'] ) ) {
1818 $ob = is_array( $options['ORDER BY'] )
1819 ?
implode( ',', $options['ORDER BY'] )
1820 : $options['ORDER BY'];
1822 return ' ORDER BY ' . $ob;
1828 public function select(
1829 $table, $vars, $conds = '', $fname = __METHOD__
, $options = [], $join_conds = []
1831 $sql = $this->selectSQLText( $table, $vars, $conds, $fname, $options, $join_conds );
1833 return $this->query( $sql, $fname );
1836 public function selectSQLText( $table, $vars, $conds = '', $fname = __METHOD__
,
1837 $options = [], $join_conds = []
1839 if ( is_array( $vars ) ) {
1840 $fields = implode( ',', $this->fieldNamesWithAlias( $vars ) );
1845 $options = (array)$options;
1846 $useIndexes = ( isset( $options['USE INDEX'] ) && is_array( $options['USE INDEX'] ) )
1847 ?
$options['USE INDEX']
1850 isset( $options['IGNORE INDEX'] ) &&
1851 is_array( $options['IGNORE INDEX'] )
1853 ?
$options['IGNORE INDEX']
1857 $this->selectOptionsIncludeLocking( $options ) &&
1858 $this->selectFieldsOrOptionsAggregate( $vars, $options )
1860 // Some DB types (postgres/oracle) disallow FOR UPDATE with aggregate
1861 // functions. Discourage use of such queries to encourage compatibility.
1863 $this->deprecationLogger
,
1864 __METHOD__
. ": aggregation used with a locking SELECT ($fname)."
1868 if ( is_array( $table ) ) {
1870 $this->tableNamesWithIndexClauseOrJOIN(
1871 $table, $useIndexes, $ignoreIndexes, $join_conds );
1872 } elseif ( $table != '' ) {
1874 $this->tableNamesWithIndexClauseOrJOIN(
1875 [ $table ], $useIndexes, $ignoreIndexes, [] );
1880 list( $startOpts, $useIndex, $preLimitTail, $postLimitTail, $ignoreIndex ) =
1881 $this->makeSelectOptions( $options );
1883 if ( is_array( $conds ) ) {
1884 $conds = $this->makeList( $conds, self
::LIST_AND
);
1887 if ( $conds === null ||
$conds === false ) {
1888 $this->queryLogger
->warning(
1892 . ' with incorrect parameters: $conds must be a string or an array'
1897 if ( $conds === '' ||
$conds === '*' ) {
1898 $sql = "SELECT $startOpts $fields $from $useIndex $ignoreIndex $preLimitTail";
1899 } elseif ( is_string( $conds ) ) {
1900 $sql = "SELECT $startOpts $fields $from $useIndex $ignoreIndex " .
1901 "WHERE $conds $preLimitTail";
1903 throw new DBUnexpectedError( $this, __METHOD__
. ' called with incorrect parameters' );
1906 if ( isset( $options['LIMIT'] ) ) {
1907 $sql = $this->limitResult( $sql, $options['LIMIT'],
1908 $options['OFFSET'] ??
false );
1910 $sql = "$sql $postLimitTail";
1912 if ( isset( $options['EXPLAIN'] ) ) {
1913 $sql = 'EXPLAIN ' . $sql;
1919 public function selectRow( $table, $vars, $conds, $fname = __METHOD__
,
1920 $options = [], $join_conds = []
1922 $options = (array)$options;
1923 $options['LIMIT'] = 1;
1925 $res = $this->select( $table, $vars, $conds, $fname, $options, $join_conds );
1926 if ( $res === false ) {
1927 throw new DBUnexpectedError( $this, "Got false from select()" );
1930 if ( !$this->numRows( $res ) ) {
1934 return $this->fetchObject( $res );
1937 public function estimateRowCount(
1938 $table, $var = '*', $conds = '', $fname = __METHOD__
, $options = [], $join_conds = []
1940 $conds = $this->normalizeConditions( $conds, $fname );
1941 $column = $this->extractSingleFieldFromList( $var );
1942 if ( is_string( $column ) && !in_array( $column, [ '*', '1' ] ) ) {
1943 $conds[] = "$column IS NOT NULL";
1946 $res = $this->select(
1947 $table, [ 'rowcount' => 'COUNT(*)' ], $conds, $fname, $options, $join_conds
1949 $row = $res ?
$this->fetchRow( $res ) : [];
1951 return isset( $row['rowcount'] ) ?
(int)$row['rowcount'] : 0;
1954 public function selectRowCount(
1955 $tables, $var = '*', $conds = '', $fname = __METHOD__
, $options = [], $join_conds = []
1957 $conds = $this->normalizeConditions( $conds, $fname );
1958 $column = $this->extractSingleFieldFromList( $var );
1959 if ( is_string( $column ) && !in_array( $column, [ '*', '1' ] ) ) {
1960 $conds[] = "$column IS NOT NULL";
1963 $res = $this->select(
1965 'tmp_count' => $this->buildSelectSubquery(
1974 [ 'rowcount' => 'COUNT(*)' ],
1978 $row = $res ?
$this->fetchRow( $res ) : [];
1980 return isset( $row['rowcount'] ) ?
(int)$row['rowcount'] : 0;
1984 * @param string|array $options
1987 private function selectOptionsIncludeLocking( $options ) {
1988 $options = (array)$options;
1989 foreach ( [ 'FOR UPDATE', 'LOCK IN SHARE MODE' ] as $lock ) {
1990 if ( in_array( $lock, $options, true ) ) {
1999 * @param array|string $fields
2000 * @param array|string $options
2003 private function selectFieldsOrOptionsAggregate( $fields, $options ) {
2004 foreach ( (array)$options as $key => $value ) {
2005 if ( is_string( $key ) ) {
2006 if ( preg_match( '/^(?:GROUP BY|HAVING)$/i', $key ) ) {
2009 } elseif ( is_string( $value ) ) {
2010 if ( preg_match( '/^(?:DISTINCT|DISTINCTROW)$/i', $value ) ) {
2016 $regex = '/^(?:COUNT|MIN|MAX|SUM|GROUP_CONCAT|LISTAGG|ARRAY_AGG)\s*\\(/i';
2017 foreach ( (array)$fields as $field ) {
2018 if ( is_string( $field ) && preg_match( $regex, $field ) ) {
2027 * @param array|string $conds
2028 * @param string $fname
2031 final protected function normalizeConditions( $conds, $fname ) {
2032 if ( $conds === null ||
$conds === false ) {
2033 $this->queryLogger
->warning(
2037 . ' with incorrect parameters: $conds must be a string or an array'
2042 if ( !is_array( $conds ) ) {
2043 $conds = ( $conds === '' ) ?
[] : [ $conds ];
2050 * @param array|string $var Field parameter in the style of select()
2051 * @return string|null Column name or null; ignores aliases
2052 * @throws DBUnexpectedError Errors out if multiple columns are given
2054 final protected function extractSingleFieldFromList( $var ) {
2055 if ( is_array( $var ) ) {
2058 } elseif ( count( $var ) == 1 ) {
2059 $column = $var[0] ??
reset( $var );
2061 throw new DBUnexpectedError( $this, __METHOD__
. ': got multiple columns.' );
2070 public function lockForUpdate(
2071 $table, $conds = '', $fname = __METHOD__
, $options = [], $join_conds = []
2073 if ( !$this->trxLevel
&& !$this->getFlag( self
::DBO_TRX
) ) {
2074 throw new DBUnexpectedError(
2076 __METHOD__
. ': no transaction is active nor is DBO_TRX set'
2080 $options = (array)$options;
2081 $options[] = 'FOR UPDATE';
2083 return $this->selectRowCount( $table, '*', $conds, $fname, $options, $join_conds );
2086 public function fieldExists( $table, $field, $fname = __METHOD__
) {
2087 $info = $this->fieldInfo( $table, $field );
2092 public function indexExists( $table, $index, $fname = __METHOD__
) {
2093 if ( !$this->tableExists( $table ) ) {
2097 $info = $this->indexInfo( $table, $index, $fname );
2098 if ( is_null( $info ) ) {
2101 return $info !== false;
2105 abstract public function tableExists( $table, $fname = __METHOD__
);
2107 public function indexUnique( $table, $index ) {
2108 $indexInfo = $this->indexInfo( $table, $index );
2110 if ( !$indexInfo ) {
2114 return !$indexInfo[0]->Non_unique
;
2118 * Helper for Database::insert().
2120 * @param array $options
2123 protected function makeInsertOptions( $options ) {
2124 return implode( ' ', $options );
2127 public function insert( $table, $a, $fname = __METHOD__
, $options = [] ) {
2128 # No rows to insert, easy just return now
2129 if ( !count( $a ) ) {
2133 $table = $this->tableName( $table );
2135 if ( !is_array( $options ) ) {
2136 $options = [ $options ];
2139 $options = $this->makeInsertOptions( $options );
2141 if ( isset( $a[0] ) && is_array( $a[0] ) ) {
2143 $keys = array_keys( $a[0] );
2146 $keys = array_keys( $a );
2149 $sql = 'INSERT ' . $options .
2150 " INTO $table (" . implode( ',', $keys ) . ') VALUES ';
2154 foreach ( $a as $row ) {
2160 $sql .= '(' . $this->makeList( $row ) . ')';
2163 $sql .= '(' . $this->makeList( $a ) . ')';
2166 $this->query( $sql, $fname );
2172 * Make UPDATE options array for Database::makeUpdateOptions
2174 * @param array $options
2177 protected function makeUpdateOptionsArray( $options ) {
2178 if ( !is_array( $options ) ) {
2179 $options = [ $options ];
2184 if ( in_array( 'IGNORE', $options ) ) {
2192 * Make UPDATE options for the Database::update function
2194 * @param array $options The options passed to Database::update
2197 protected function makeUpdateOptions( $options ) {
2198 $opts = $this->makeUpdateOptionsArray( $options );
2200 return implode( ' ', $opts );
2203 public function update( $table, $values, $conds, $fname = __METHOD__
, $options = [] ) {
2204 $table = $this->tableName( $table );
2205 $opts = $this->makeUpdateOptions( $options );
2206 $sql = "UPDATE $opts $table SET " . $this->makeList( $values, self
::LIST_SET
);
2208 if ( $conds !== [] && $conds !== '*' ) {
2209 $sql .= " WHERE " . $this->makeList( $conds, self
::LIST_AND
);
2212 $this->query( $sql, $fname );
2217 public function makeList( $a, $mode = self
::LIST_COMMA
) {
2218 if ( !is_array( $a ) ) {
2219 throw new DBUnexpectedError( $this, __METHOD__
. ' called with incorrect parameters' );
2225 foreach ( $a as $field => $value ) {
2227 if ( $mode == self
::LIST_AND
) {
2229 } elseif ( $mode == self
::LIST_OR
) {
2238 if ( ( $mode == self
::LIST_AND ||
$mode == self
::LIST_OR
) && is_numeric( $field ) ) {
2239 $list .= "($value)";
2240 } elseif ( $mode == self
::LIST_SET
&& is_numeric( $field ) ) {
2243 ( $mode == self
::LIST_AND ||
$mode == self
::LIST_OR
) && is_array( $value )
2245 // Remove null from array to be handled separately if found
2246 $includeNull = false;
2247 foreach ( array_keys( $value, null, true ) as $nullKey ) {
2248 $includeNull = true;
2249 unset( $value[$nullKey] );
2251 if ( count( $value ) == 0 && !$includeNull ) {
2252 throw new InvalidArgumentException(
2253 __METHOD__
. ": empty input for field $field" );
2254 } elseif ( count( $value ) == 0 ) {
2255 // only check if $field is null
2256 $list .= "$field IS NULL";
2258 // IN clause contains at least one valid element
2259 if ( $includeNull ) {
2260 // Group subconditions to ensure correct precedence
2263 if ( count( $value ) == 1 ) {
2264 // Special-case single values, as IN isn't terribly efficient
2265 // Don't necessarily assume the single key is 0; we don't
2266 // enforce linear numeric ordering on other arrays here.
2267 $value = array_values( $value )[0];
2268 $list .= $field . " = " . $this->addQuotes( $value );
2270 $list .= $field . " IN (" . $this->makeList( $value ) . ") ";
2272 // if null present in array, append IS NULL
2273 if ( $includeNull ) {
2274 $list .= " OR $field IS NULL)";
2277 } elseif ( $value === null ) {
2278 if ( $mode == self
::LIST_AND ||
$mode == self
::LIST_OR
) {
2279 $list .= "$field IS ";
2280 } elseif ( $mode == self
::LIST_SET
) {
2281 $list .= "$field = ";
2286 $mode == self
::LIST_AND ||
$mode == self
::LIST_OR ||
$mode == self
::LIST_SET
2288 $list .= "$field = ";
2290 $list .= $mode == self
::LIST_NAMES ?
$value : $this->addQuotes( $value );
2297 public function makeWhereFrom2d( $data, $baseKey, $subKey ) {
2300 foreach ( $data as $base => $sub ) {
2301 if ( count( $sub ) ) {
2302 $conds[] = $this->makeList(
2303 [ $baseKey => $base, $subKey => array_keys( $sub ) ],
2309 return $this->makeList( $conds, self
::LIST_OR
);
2311 // Nothing to search for...
2316 public function aggregateValue( $valuedata, $valuename = 'value' ) {
2320 public function bitNot( $field ) {
2324 public function bitAnd( $fieldLeft, $fieldRight ) {
2325 return "($fieldLeft & $fieldRight)";
2328 public function bitOr( $fieldLeft, $fieldRight ) {
2329 return "($fieldLeft | $fieldRight)";
2332 public function buildConcat( $stringList ) {
2333 return 'CONCAT(' . implode( ',', $stringList ) . ')';
2336 public function buildGroupConcatField(
2337 $delim, $table, $field, $conds = '', $join_conds = []
2339 $fld = "GROUP_CONCAT($field SEPARATOR " . $this->addQuotes( $delim ) . ')';
2341 return '(' . $this->selectSQLText( $table, $fld, $conds, null, [], $join_conds ) . ')';
2344 public function buildSubstring( $input, $startPosition, $length = null ) {
2345 $this->assertBuildSubstringParams( $startPosition, $length );
2346 $functionBody = "$input FROM $startPosition";
2347 if ( $length !== null ) {
2348 $functionBody .= " FOR $length";
2350 return 'SUBSTRING(' . $functionBody . ')';
2354 * Check type and bounds for parameters to self::buildSubstring()
2356 * All supported databases have substring functions that behave the same for
2357 * positive $startPosition and non-negative $length, but behaviors differ when
2358 * given 0 or negative $startPosition or negative $length. The simplest
2359 * solution to that is to just forbid those values.
2361 * @param int $startPosition
2362 * @param int|null $length
2365 protected function assertBuildSubstringParams( $startPosition, $length ) {
2366 if ( !is_int( $startPosition ) ||
$startPosition <= 0 ) {
2367 throw new InvalidArgumentException(
2368 '$startPosition must be a positive integer'
2371 if ( !( is_int( $length ) && $length >= 0 ||
$length === null ) ) {
2372 throw new InvalidArgumentException(
2373 '$length must be null or an integer greater than or equal to 0'
2378 public function buildStringCast( $field ) {
2379 // In theory this should work for any standards-compliant
2380 // SQL implementation, although it may not be the best way to do it.
2381 return "CAST( $field AS CHARACTER )";
2384 public function buildIntegerCast( $field ) {
2385 return 'CAST( ' . $field . ' AS INTEGER )';
2388 public function buildSelectSubquery(
2389 $table, $vars, $conds = '', $fname = __METHOD__
,
2390 $options = [], $join_conds = []
2392 return new Subquery(
2393 $this->selectSQLText( $table, $vars, $conds, $fname, $options, $join_conds )
2397 public function databasesAreIndependent() {
2401 final public function selectDB( $db ) {
2402 $this->selectDomain( new DatabaseDomain(
2404 $this->currentDomain
->getSchema(),
2405 $this->currentDomain
->getTablePrefix()
2411 final public function selectDomain( $domain ) {
2412 $this->doSelectDomain( DatabaseDomain
::newFromId( $domain ) );
2415 protected function doSelectDomain( DatabaseDomain
$domain ) {
2416 $this->currentDomain
= $domain;
2419 public function getDBname() {
2420 return $this->currentDomain
->getDatabase();
2423 public function getServer() {
2424 return $this->server
;
2427 public function tableName( $name, $format = 'quoted' ) {
2428 if ( $name instanceof Subquery
) {
2429 throw new DBUnexpectedError(
2431 __METHOD__
. ': got Subquery instance when expecting a string.'
2435 # Skip the entire process when we have a string quoted on both ends.
2436 # Note that we check the end so that we will still quote any use of
2437 # use of `database`.table. But won't break things if someone wants
2438 # to query a database table with a dot in the name.
2439 if ( $this->isQuotedIdentifier( $name ) ) {
2443 # Lets test for any bits of text that should never show up in a table
2444 # name. Basically anything like JOIN or ON which are actually part of
2445 # SQL queries, but may end up inside of the table value to combine
2446 # sql. Such as how the API is doing.
2447 # Note that we use a whitespace test rather than a \b test to avoid
2448 # any remote case where a word like on may be inside of a table name
2449 # surrounded by symbols which may be considered word breaks.
2450 if ( preg_match( '/(^|\s)(DISTINCT|JOIN|ON|AS)(\s|$)/i', $name ) !== 0 ) {
2451 $this->queryLogger
->warning(
2452 __METHOD__
. ": use of subqueries is not supported this way.",
2453 [ 'trace' => ( new RuntimeException() )->getTraceAsString() ]
2459 # Split database and table into proper variables.
2460 list( $database, $schema, $prefix, $table ) = $this->qualifiedTableComponents( $name );
2462 # Quote $table and apply the prefix if not quoted.
2463 # $tableName might be empty if this is called from Database::replaceVars()
2464 $tableName = "{$prefix}{$table}";
2465 if ( $format === 'quoted'
2466 && !$this->isQuotedIdentifier( $tableName )
2467 && $tableName !== ''
2469 $tableName = $this->addIdentifierQuotes( $tableName );
2472 # Quote $schema and $database and merge them with the table name if needed
2473 $tableName = $this->prependDatabaseOrSchema( $schema, $tableName, $format );
2474 $tableName = $this->prependDatabaseOrSchema( $database, $tableName, $format );
2480 * Get the table components needed for a query given the currently selected database
2482 * @param string $name Table name in the form of db.schema.table, db.table, or table
2483 * @return array (DB name or "" for default, schema name, table prefix, table name)
2485 protected function qualifiedTableComponents( $name ) {
2486 # We reverse the explode so that database.table and table both output the correct table.
2487 $dbDetails = explode( '.', $name, 3 );
2488 if ( count( $dbDetails ) == 3 ) {
2489 list( $database, $schema, $table ) = $dbDetails;
2490 # We don't want any prefix added in this case
2492 } elseif ( count( $dbDetails ) == 2 ) {
2493 list( $database, $table ) = $dbDetails;
2494 # We don't want any prefix added in this case
2496 # In dbs that support it, $database may actually be the schema
2497 # but that doesn't affect any of the functionality here
2500 list( $table ) = $dbDetails;
2501 if ( isset( $this->tableAliases
[$table] ) ) {
2502 $database = $this->tableAliases
[$table]['dbname'];
2503 $schema = is_string( $this->tableAliases
[$table]['schema'] )
2504 ?
$this->tableAliases
[$table]['schema']
2505 : $this->relationSchemaQualifier();
2506 $prefix = is_string( $this->tableAliases
[$table]['prefix'] )
2507 ?
$this->tableAliases
[$table]['prefix']
2508 : $this->tablePrefix();
2511 $schema = $this->relationSchemaQualifier(); # Default schema
2512 $prefix = $this->tablePrefix(); # Default prefix
2516 return [ $database, $schema, $prefix, $table ];
2520 * @param string|null $namespace Database or schema
2521 * @param string $relation Name of table, view, sequence, etc...
2522 * @param string $format One of (raw, quoted)
2523 * @return string Relation name with quoted and merged $namespace as needed
2525 private function prependDatabaseOrSchema( $namespace, $relation, $format ) {
2526 if ( strlen( $namespace ) ) {
2527 if ( $format === 'quoted' && !$this->isQuotedIdentifier( $namespace ) ) {
2528 $namespace = $this->addIdentifierQuotes( $namespace );
2530 $relation = $namespace . '.' . $relation;
2536 public function tableNames() {
2537 $inArray = func_get_args();
2540 foreach ( $inArray as $name ) {
2541 $retVal[$name] = $this->tableName( $name );
2547 public function tableNamesN() {
2548 $inArray = func_get_args();
2551 foreach ( $inArray as $name ) {
2552 $retVal[] = $this->tableName( $name );
2559 * Get an aliased table name
2561 * This returns strings like "tableName AS newTableName" for aliased tables
2562 * and "(SELECT * from tableA) newTablename" for subqueries (e.g. derived tables)
2564 * @see Database::tableName()
2565 * @param string|Subquery $table Table name or object with a 'sql' field
2566 * @param string|bool $alias Table alias (optional)
2567 * @return string SQL name for aliased table. Will not alias a table to its own name
2569 protected function tableNameWithAlias( $table, $alias = false ) {
2570 if ( is_string( $table ) ) {
2571 $quotedTable = $this->tableName( $table );
2572 } elseif ( $table instanceof Subquery
) {
2573 $quotedTable = (string)$table;
2575 throw new InvalidArgumentException( "Table must be a string or Subquery." );
2578 if ( $alias === false ||
$alias === $table ) {
2579 if ( $table instanceof Subquery
) {
2580 throw new InvalidArgumentException( "Subquery table missing alias." );
2583 return $quotedTable;
2585 return $quotedTable . ' ' . $this->addIdentifierQuotes( $alias );
2590 * Gets an array of aliased table names
2592 * @param array $tables [ [alias] => table ]
2593 * @return string[] See tableNameWithAlias()
2595 protected function tableNamesWithAlias( $tables ) {
2597 foreach ( $tables as $alias => $table ) {
2598 if ( is_numeric( $alias ) ) {
2601 $retval[] = $this->tableNameWithAlias( $table, $alias );
2608 * Get an aliased field name
2609 * e.g. fieldName AS newFieldName
2611 * @param string $name Field name
2612 * @param string|bool $alias Alias (optional)
2613 * @return string SQL name for aliased field. Will not alias a field to its own name
2615 protected function fieldNameWithAlias( $name, $alias = false ) {
2616 if ( !$alias ||
(string)$alias === (string)$name ) {
2619 return $name . ' AS ' . $this->addIdentifierQuotes( $alias ); // PostgreSQL needs AS
2624 * Gets an array of aliased field names
2626 * @param array $fields [ [alias] => field ]
2627 * @return string[] See fieldNameWithAlias()
2629 protected function fieldNamesWithAlias( $fields ) {
2631 foreach ( $fields as $alias => $field ) {
2632 if ( is_numeric( $alias ) ) {
2635 $retval[] = $this->fieldNameWithAlias( $field, $alias );
2642 * Get the aliased table name clause for a FROM clause
2643 * which might have a JOIN and/or USE INDEX or IGNORE INDEX clause
2645 * @param array $tables ( [alias] => table )
2646 * @param array $use_index Same as for select()
2647 * @param array $ignore_index Same as for select()
2648 * @param array $join_conds Same as for select()
2651 protected function tableNamesWithIndexClauseOrJOIN(
2652 $tables, $use_index = [], $ignore_index = [], $join_conds = []
2656 $use_index = (array)$use_index;
2657 $ignore_index = (array)$ignore_index;
2658 $join_conds = (array)$join_conds;
2660 foreach ( $tables as $alias => $table ) {
2661 if ( !is_string( $alias ) ) {
2662 // No alias? Set it equal to the table name
2666 if ( is_array( $table ) ) {
2667 // A parenthesized group
2668 if ( count( $table ) > 1 ) {
2669 $joinedTable = '(' .
2670 $this->tableNamesWithIndexClauseOrJOIN(
2671 $table, $use_index, $ignore_index, $join_conds ) . ')';
2674 $innerTable = reset( $table );
2675 $innerAlias = key( $table );
2676 $joinedTable = $this->tableNameWithAlias(
2678 is_string( $innerAlias ) ?
$innerAlias : $innerTable
2682 $joinedTable = $this->tableNameWithAlias( $table, $alias );
2685 // Is there a JOIN clause for this table?
2686 if ( isset( $join_conds[$alias] ) ) {
2687 list( $joinType, $conds ) = $join_conds[$alias];
2688 $tableClause = $joinType;
2689 $tableClause .= ' ' . $joinedTable;
2690 if ( isset( $use_index[$alias] ) ) { // has USE INDEX?
2691 $use = $this->useIndexClause( implode( ',', (array)$use_index[$alias] ) );
2693 $tableClause .= ' ' . $use;
2696 if ( isset( $ignore_index[$alias] ) ) { // has IGNORE INDEX?
2697 $ignore = $this->ignoreIndexClause(
2698 implode( ',', (array)$ignore_index[$alias] ) );
2699 if ( $ignore != '' ) {
2700 $tableClause .= ' ' . $ignore;
2703 $on = $this->makeList( (array)$conds, self
::LIST_AND
);
2705 $tableClause .= ' ON (' . $on . ')';
2708 $retJOIN[] = $tableClause;
2709 } elseif ( isset( $use_index[$alias] ) ) {
2710 // Is there an INDEX clause for this table?
2711 $tableClause = $joinedTable;
2712 $tableClause .= ' ' . $this->useIndexClause(
2713 implode( ',', (array)$use_index[$alias] )
2716 $ret[] = $tableClause;
2717 } elseif ( isset( $ignore_index[$alias] ) ) {
2718 // Is there an INDEX clause for this table?
2719 $tableClause = $joinedTable;
2720 $tableClause .= ' ' . $this->ignoreIndexClause(
2721 implode( ',', (array)$ignore_index[$alias] )
2724 $ret[] = $tableClause;
2726 $tableClause = $joinedTable;
2728 $ret[] = $tableClause;
2732 // We can't separate explicit JOIN clauses with ',', use ' ' for those
2733 $implicitJoins = implode( ',', $ret );
2734 $explicitJoins = implode( ' ', $retJOIN );
2736 // Compile our final table clause
2737 return implode( ' ', [ $implicitJoins, $explicitJoins ] );
2741 * Allows for index remapping in queries where this is not consistent across DBMS
2743 * @param string $index
2746 protected function indexName( $index ) {
2747 return $this->indexAliases
[$index] ??
$index;
2750 public function addQuotes( $s ) {
2751 if ( $s instanceof Blob
) {
2754 if ( $s === null ) {
2756 } elseif ( is_bool( $s ) ) {
2759 # This will also quote numeric values. This should be harmless,
2760 # and protects against weird problems that occur when they really
2761 # _are_ strings such as article titles and string->number->string
2762 # conversion is not 1:1.
2763 return "'" . $this->strencode( $s ) . "'";
2767 public function addIdentifierQuotes( $s ) {
2768 return '"' . str_replace( '"', '""', $s ) . '"';
2772 * Returns if the given identifier looks quoted or not according to
2773 * the database convention for quoting identifiers .
2775 * @note Do not use this to determine if untrusted input is safe.
2776 * A malicious user can trick this function.
2777 * @param string $name
2780 public function isQuotedIdentifier( $name ) {
2781 return $name[0] == '"' && substr( $name, -1, 1 ) == '"';
2786 * @param string $escapeChar
2789 protected function escapeLikeInternal( $s, $escapeChar = '`' ) {
2790 return str_replace( [ $escapeChar, '%', '_' ],
2791 [ "{$escapeChar}{$escapeChar}", "{$escapeChar}%", "{$escapeChar}_" ],
2795 public function buildLike() {
2796 $params = func_get_args();
2798 if ( count( $params ) > 0 && is_array( $params[0] ) ) {
2799 $params = $params[0];
2804 // We use ` instead of \ as the default LIKE escape character, since addQuotes()
2805 // may escape backslashes, creating problems of double escaping. The `
2806 // character has good cross-DBMS compatibility, avoiding special operators
2807 // in MS SQL like ^ and %
2810 foreach ( $params as $value ) {
2811 if ( $value instanceof LikeMatch
) {
2812 $s .= $value->toString();
2814 $s .= $this->escapeLikeInternal( $value, $escapeChar );
2819 $this->addQuotes( $s ) . ' ESCAPE ' . $this->addQuotes( $escapeChar ) . ' ';
2822 public function anyChar() {
2823 return new LikeMatch( '_' );
2826 public function anyString() {
2827 return new LikeMatch( '%' );
2830 public function nextSequenceValue( $seqName ) {
2835 * USE INDEX clause. Unlikely to be useful for anything but MySQL. This
2836 * is only needed because a) MySQL must be as efficient as possible due to
2837 * its use on Wikipedia, and b) MySQL 4.0 is kind of dumb sometimes about
2838 * which index to pick. Anyway, other databases might have different
2839 * indexes on a given table. So don't bother overriding this unless you're
2841 * @param string $index
2844 public function useIndexClause( $index ) {
2849 * IGNORE INDEX clause. Unlikely to be useful for anything but MySQL. This
2850 * is only needed because a) MySQL must be as efficient as possible due to
2851 * its use on Wikipedia, and b) MySQL 4.0 is kind of dumb sometimes about
2852 * which index to pick. Anyway, other databases might have different
2853 * indexes on a given table. So don't bother overriding this unless you're
2855 * @param string $index
2858 public function ignoreIndexClause( $index ) {
2862 public function replace( $table, $uniqueIndexes, $rows, $fname = __METHOD__
) {
2863 if ( count( $rows ) == 0 ) {
2867 $uniqueIndexes = (array)$uniqueIndexes;
2869 if ( !is_array( reset( $rows ) ) ) {
2874 $this->startAtomic( $fname, self
::ATOMIC_CANCELABLE
);
2875 $affectedRowCount = 0;
2876 foreach ( $rows as $row ) {
2877 // Delete rows which collide with this one
2878 $indexWhereClauses = [];
2879 foreach ( $uniqueIndexes as $index ) {
2880 $indexColumns = (array)$index;
2881 $indexRowValues = array_intersect_key( $row, array_flip( $indexColumns ) );
2882 if ( count( $indexRowValues ) != count( $indexColumns ) ) {
2883 throw new DBUnexpectedError(
2885 'New record does not provide all values for unique key (' .
2886 implode( ', ', $indexColumns ) . ')'
2888 } elseif ( in_array( null, $indexRowValues, true ) ) {
2889 throw new DBUnexpectedError(
2891 'New record has a null value for unique key (' .
2892 implode( ', ', $indexColumns ) . ')'
2895 $indexWhereClauses[] = $this->makeList( $indexRowValues, LIST_AND
);
2898 if ( $indexWhereClauses ) {
2899 $this->delete( $table, $this->makeList( $indexWhereClauses, LIST_OR
), $fname );
2900 $affectedRowCount +
= $this->affectedRows();
2903 // Now insert the row
2904 $this->insert( $table, $row, $fname );
2905 $affectedRowCount +
= $this->affectedRows();
2907 $this->endAtomic( $fname );
2908 $this->affectedRowCount
= $affectedRowCount;
2909 } catch ( Exception
$e ) {
2910 $this->cancelAtomic( $fname );
2916 * REPLACE query wrapper for MySQL and SQLite, which have a native REPLACE
2919 * @param string $table Table name
2920 * @param array|string $rows Row(s) to insert
2921 * @param string $fname Caller function name
2923 protected function nativeReplace( $table, $rows, $fname ) {
2924 $table = $this->tableName( $table );
2927 if ( !is_array( reset( $rows ) ) ) {
2931 $sql = "REPLACE INTO $table (" . implode( ',', array_keys( $rows[0] ) ) . ') VALUES ';
2934 foreach ( $rows as $row ) {
2941 $sql .= '(' . $this->makeList( $row ) . ')';
2944 $this->query( $sql, $fname );
2947 public function upsert( $table, array $rows, $uniqueIndexes, array $set,
2950 if ( $rows === [] ) {
2951 return true; // nothing to do
2954 $uniqueIndexes = (array)$uniqueIndexes;
2955 if ( !is_array( reset( $rows ) ) ) {
2959 if ( count( $uniqueIndexes ) ) {
2960 $clauses = []; // list WHERE clauses that each identify a single row
2961 foreach ( $rows as $row ) {
2962 foreach ( $uniqueIndexes as $index ) {
2963 $index = is_array( $index ) ?
$index : [ $index ]; // columns
2964 $rowKey = []; // unique key to this row
2965 foreach ( $index as $column ) {
2966 $rowKey[$column] = $row[$column];
2968 $clauses[] = $this->makeList( $rowKey, self
::LIST_AND
);
2971 $where = [ $this->makeList( $clauses, self
::LIST_OR
) ];
2976 $affectedRowCount = 0;
2978 $this->startAtomic( $fname, self
::ATOMIC_CANCELABLE
);
2979 # Update any existing conflicting row(s)
2980 if ( $where !== false ) {
2981 $this->update( $table, $set, $where, $fname );
2982 $affectedRowCount +
= $this->affectedRows();
2984 # Now insert any non-conflicting row(s)
2985 $this->insert( $table, $rows, $fname, [ 'IGNORE' ] );
2986 $affectedRowCount +
= $this->affectedRows();
2987 $this->endAtomic( $fname );
2988 $this->affectedRowCount
= $affectedRowCount;
2989 } catch ( Exception
$e ) {
2990 $this->cancelAtomic( $fname );
2997 public function deleteJoin( $delTable, $joinTable, $delVar, $joinVar, $conds,
3001 throw new DBUnexpectedError( $this, __METHOD__
. ' called with empty $conds' );
3004 $delTable = $this->tableName( $delTable );
3005 $joinTable = $this->tableName( $joinTable );
3006 $sql = "DELETE FROM $delTable WHERE $delVar IN (SELECT $joinVar FROM $joinTable ";
3007 if ( $conds != '*' ) {
3008 $sql .= 'WHERE ' . $this->makeList( $conds, self
::LIST_AND
);
3012 $this->query( $sql, $fname );
3015 public function textFieldSize( $table, $field ) {
3016 $table = $this->tableName( $table );
3017 $sql = "SHOW COLUMNS FROM $table LIKE \"$field\";";
3018 $res = $this->query( $sql, __METHOD__
);
3019 $row = $this->fetchObject( $res );
3023 if ( preg_match( '/\((.*)\)/', $row->Type
, $m ) ) {
3032 public function delete( $table, $conds, $fname = __METHOD__
) {
3034 throw new DBUnexpectedError( $this, __METHOD__
. ' called with no conditions' );
3037 $table = $this->tableName( $table );
3038 $sql = "DELETE FROM $table";
3040 if ( $conds != '*' ) {
3041 if ( is_array( $conds ) ) {
3042 $conds = $this->makeList( $conds, self
::LIST_AND
);
3044 $sql .= ' WHERE ' . $conds;
3047 $this->query( $sql, $fname );
3052 final public function insertSelect(
3053 $destTable, $srcTable, $varMap, $conds,
3054 $fname = __METHOD__
, $insertOptions = [], $selectOptions = [], $selectJoinConds = []
3056 static $hints = [ 'NO_AUTO_COLUMNS' ];
3058 $insertOptions = (array)$insertOptions;
3059 $selectOptions = (array)$selectOptions;
3061 if ( $this->cliMode
&& $this->isInsertSelectSafe( $insertOptions, $selectOptions ) ) {
3062 // For massive migrations with downtime, we don't want to select everything
3063 // into memory and OOM, so do all this native on the server side if possible.
3064 $this->nativeInsertSelect(
3070 array_diff( $insertOptions, $hints ),
3075 $this->nonNativeInsertSelect(
3081 array_diff( $insertOptions, $hints ),
3091 * @param array $insertOptions INSERT options
3092 * @param array $selectOptions SELECT options
3093 * @return bool Whether an INSERT SELECT with these options will be replication safe
3096 protected function isInsertSelectSafe( array $insertOptions, array $selectOptions ) {
3101 * Implementation of insertSelect() based on select() and insert()
3103 * @see IDatabase::insertSelect()
3105 * @param string $destTable
3106 * @param string|array $srcTable
3107 * @param array $varMap
3108 * @param array $conds
3109 * @param string $fname
3110 * @param array $insertOptions
3111 * @param array $selectOptions
3112 * @param array $selectJoinConds
3114 protected function nonNativeInsertSelect( $destTable, $srcTable, $varMap, $conds,
3115 $fname = __METHOD__
,
3116 $insertOptions = [], $selectOptions = [], $selectJoinConds = []
3118 // For web requests, do a locking SELECT and then INSERT. This puts the SELECT burden
3119 // on only the master (without needing row-based-replication). It also makes it easy to
3120 // know how big the INSERT is going to be.
3122 foreach ( $varMap as $dstColumn => $sourceColumnOrSql ) {
3123 $fields[] = $this->fieldNameWithAlias( $sourceColumnOrSql, $dstColumn );
3125 $selectOptions[] = 'FOR UPDATE';
3126 $res = $this->select(
3127 $srcTable, implode( ',', $fields ), $conds, $fname, $selectOptions, $selectJoinConds
3134 $affectedRowCount = 0;
3135 $this->startAtomic( $fname, self
::ATOMIC_CANCELABLE
);
3138 foreach ( $res as $row ) {
3139 $rows[] = (array)$row;
3141 // Avoid inserts that are too huge
3142 if ( count( $rows ) >= $this->nonNativeInsertSelectBatchSize
) {
3143 $ok = $this->insert( $destTable, $rows, $fname, $insertOptions );
3147 $affectedRowCount +
= $this->affectedRows();
3151 if ( $rows && $ok ) {
3152 $ok = $this->insert( $destTable, $rows, $fname, $insertOptions );
3154 $affectedRowCount +
= $this->affectedRows();
3158 $this->endAtomic( $fname );
3159 $this->affectedRowCount
= $affectedRowCount;
3161 $this->cancelAtomic( $fname );
3163 } catch ( Exception
$e ) {
3164 $this->cancelAtomic( $fname );
3170 * Native server-side implementation of insertSelect() for situations where
3171 * we don't want to select everything into memory
3173 * @see IDatabase::insertSelect()
3174 * @param string $destTable
3175 * @param string|array $srcTable
3176 * @param array $varMap
3177 * @param array $conds
3178 * @param string $fname
3179 * @param array $insertOptions
3180 * @param array $selectOptions
3181 * @param array $selectJoinConds
3183 protected function nativeInsertSelect( $destTable, $srcTable, $varMap, $conds,
3184 $fname = __METHOD__
,
3185 $insertOptions = [], $selectOptions = [], $selectJoinConds = []
3187 $destTable = $this->tableName( $destTable );
3189 if ( !is_array( $insertOptions ) ) {
3190 $insertOptions = [ $insertOptions ];
3193 $insertOptions = $this->makeInsertOptions( $insertOptions );
3195 $selectSql = $this->selectSQLText(
3197 array_values( $varMap ),
3204 $sql = "INSERT $insertOptions" .
3205 " INTO $destTable (" . implode( ',', array_keys( $varMap ) ) . ') ' .
3208 $this->query( $sql, $fname );
3211 public function limitResult( $sql, $limit, $offset = false ) {
3212 if ( !is_numeric( $limit ) ) {
3213 throw new DBUnexpectedError( $this,
3214 "Invalid non-numeric limit passed to limitResult()\n" );
3216 // This version works in MySQL and SQLite. It will very likely need to be
3217 // overridden for most other RDBMS subclasses.
3218 return "$sql LIMIT "
3219 . ( ( is_numeric( $offset ) && $offset != 0 ) ?
"{$offset}," : "" )
3223 public function unionSupportsOrderAndLimit() {
3224 return true; // True for almost every DB supported
3227 public function unionQueries( $sqls, $all ) {
3228 $glue = $all ?
') UNION ALL (' : ') UNION (';
3230 return '(' . implode( $glue, $sqls ) . ')';
3233 public function unionConditionPermutations(
3234 $table, $vars, array $permute_conds, $extra_conds = '', $fname = __METHOD__
,
3235 $options = [], $join_conds = []
3237 // First, build the Cartesian product of $permute_conds
3239 foreach ( $permute_conds as $field => $values ) {
3241 // Skip empty $values
3244 $values = array_unique( $values ); // For sanity
3246 foreach ( $conds as $cond ) {
3247 foreach ( $values as $value ) {
3248 $cond[$field] = $value;
3249 $newConds[] = $cond; // Arrays are by-value, not by-reference, so this works
3255 $extra_conds = $extra_conds === '' ?
[] : (array)$extra_conds;
3257 // If there's just one condition and no subordering, hand off to
3258 // selectSQLText directly.
3259 if ( count( $conds ) === 1 &&
3260 ( !isset( $options['INNER ORDER BY'] ) ||
!$this->unionSupportsOrderAndLimit() )
3262 return $this->selectSQLText(
3263 $table, $vars, $conds[0] +
$extra_conds, $fname, $options, $join_conds
3267 // Otherwise, we need to pull out the order and limit to apply after
3268 // the union. Then build the SQL queries for each set of conditions in
3269 // $conds. Then union them together (using UNION ALL, because the
3270 // product *should* already be distinct).
3271 $orderBy = $this->makeOrderBy( $options );
3272 $limit = $options['LIMIT'] ??
null;
3273 $offset = $options['OFFSET'] ??
false;
3274 $all = empty( $options['NOTALL'] ) && !in_array( 'NOTALL', $options );
3275 if ( !$this->unionSupportsOrderAndLimit() ) {
3276 unset( $options['ORDER BY'], $options['LIMIT'], $options['OFFSET'] );
3278 if ( array_key_exists( 'INNER ORDER BY', $options ) ) {
3279 $options['ORDER BY'] = $options['INNER ORDER BY'];
3281 if ( $limit !== null && is_numeric( $offset ) && $offset != 0 ) {
3282 // We need to increase the limit by the offset rather than
3283 // using the offset directly, otherwise it'll skip incorrectly
3284 // in the subqueries.
3285 $options['LIMIT'] = $limit +
$offset;
3286 unset( $options['OFFSET'] );
3291 foreach ( $conds as $cond ) {
3292 $sqls[] = $this->selectSQLText(
3293 $table, $vars, $cond +
$extra_conds, $fname, $options, $join_conds
3296 $sql = $this->unionQueries( $sqls, $all ) . $orderBy;
3297 if ( $limit !== null ) {
3298 $sql = $this->limitResult( $sql, $limit, $offset );
3304 public function conditional( $cond, $trueVal, $falseVal ) {
3305 if ( is_array( $cond ) ) {
3306 $cond = $this->makeList( $cond, self
::LIST_AND
);
3309 return " (CASE WHEN $cond THEN $trueVal ELSE $falseVal END) ";
3312 public function strreplace( $orig, $old, $new ) {
3313 return "REPLACE({$orig}, {$old}, {$new})";
3316 public function getServerUptime() {
3320 public function wasDeadlock() {
3324 public function wasLockTimeout() {
3328 public function wasConnectionLoss() {
3329 return $this->wasConnectionError( $this->lastErrno() );
3332 public function wasReadOnlyError() {
3336 public function wasErrorReissuable() {
3338 $this->wasDeadlock() ||
3339 $this->wasLockTimeout() ||
3340 $this->wasConnectionLoss()
3345 * Do not use this method outside of Database/DBError classes
3347 * @param int|string $errno
3348 * @return bool Whether the given query error was a connection drop
3350 public function wasConnectionError( $errno ) {
3355 * @return bool Whether it is known that the last query error only caused statement rollback
3356 * @note This is for backwards compatibility for callers catching DBError exceptions in
3357 * order to ignore problems like duplicate key errors or foriegn key violations
3360 protected function wasKnownStatementRollbackError() {
3361 return false; // don't know; it could have caused a transaction rollback
3364 public function deadlockLoop() {
3365 $args = func_get_args();
3366 $function = array_shift( $args );
3367 $tries = self
::DEADLOCK_TRIES
;
3369 $this->begin( __METHOD__
);
3372 /** @var Exception $e */
3376 $retVal = $function( ...$args );
3378 } catch ( DBQueryError
$e ) {
3379 if ( $this->wasDeadlock() ) {
3380 // Retry after a randomized delay
3381 usleep( mt_rand( self
::DEADLOCK_DELAY_MIN
, self
::DEADLOCK_DELAY_MAX
) );
3383 // Throw the error back up
3387 } while ( --$tries > 0 );
3389 if ( $tries <= 0 ) {
3390 // Too many deadlocks; give up
3391 $this->rollback( __METHOD__
);
3394 $this->commit( __METHOD__
);
3400 public function masterPosWait( DBMasterPos
$pos, $timeout ) {
3401 # Real waits are implemented in the subclass.
3405 public function getReplicaPos() {
3410 public function getMasterPos() {
3415 public function serverIsReadOnly() {
3419 final public function onTransactionResolution( callable
$callback, $fname = __METHOD__
) {
3420 if ( !$this->trxLevel
) {
3421 throw new DBUnexpectedError( $this, "No transaction is active." );
3423 $this->trxEndCallbacks
[] = [ $callback, $fname, $this->currentAtomicSectionId() ];
3426 final public function onTransactionCommitOrIdle( callable
$callback, $fname = __METHOD__
) {
3427 if ( !$this->trxLevel
&& $this->getTransactionRoundId() ) {
3428 // Start an implicit transaction similar to how query() does
3429 $this->begin( __METHOD__
, self
::TRANSACTION_INTERNAL
);
3430 $this->trxAutomatic
= true;
3433 $this->trxIdleCallbacks
[] = [ $callback, $fname, $this->currentAtomicSectionId() ];
3434 if ( !$this->trxLevel
) {
3435 $this->runOnTransactionIdleCallbacks( self
::TRIGGER_IDLE
);
3439 final public function onTransactionIdle( callable
$callback, $fname = __METHOD__
) {
3440 $this->onTransactionCommitOrIdle( $callback, $fname );
3443 final public function onTransactionPreCommitOrIdle( callable
$callback, $fname = __METHOD__
) {
3444 if ( !$this->trxLevel
&& $this->getTransactionRoundId() ) {
3445 // Start an implicit transaction similar to how query() does
3446 $this->begin( __METHOD__
, self
::TRANSACTION_INTERNAL
);
3447 $this->trxAutomatic
= true;
3450 if ( $this->trxLevel
) {
3451 $this->trxPreCommitCallbacks
[] = [ $callback, $fname, $this->currentAtomicSectionId() ];
3453 // No transaction is active nor will start implicitly, so make one for this callback
3454 $this->startAtomic( __METHOD__
, self
::ATOMIC_CANCELABLE
);
3457 $this->endAtomic( __METHOD__
);
3458 } catch ( Exception
$e ) {
3459 $this->cancelAtomic( __METHOD__
);
3466 * @return AtomicSectionIdentifier|null ID of the topmost atomic section level
3468 private function currentAtomicSectionId() {
3469 if ( $this->trxLevel
&& $this->trxAtomicLevels
) {
3470 $levelInfo = end( $this->trxAtomicLevels
);
3472 return $levelInfo[1];
3479 * @param AtomicSectionIdentifier $old
3480 * @param AtomicSectionIdentifier $new
3482 private function reassignCallbacksForSection(
3483 AtomicSectionIdentifier
$old, AtomicSectionIdentifier
$new
3485 foreach ( $this->trxPreCommitCallbacks
as $key => $info ) {
3486 if ( $info[2] === $old ) {
3487 $this->trxPreCommitCallbacks
[$key][2] = $new;
3490 foreach ( $this->trxIdleCallbacks
as $key => $info ) {
3491 if ( $info[2] === $old ) {
3492 $this->trxIdleCallbacks
[$key][2] = $new;
3495 foreach ( $this->trxEndCallbacks
as $key => $info ) {
3496 if ( $info[2] === $old ) {
3497 $this->trxEndCallbacks
[$key][2] = $new;
3503 * @param AtomicSectionIdentifier[] $sectionIds ID of an actual savepoint
3504 * @throws UnexpectedValueException
3506 private function modifyCallbacksForCancel( array $sectionIds ) {
3507 // Cancel the "on commit" callbacks owned by this savepoint
3508 $this->trxIdleCallbacks
= array_filter(
3509 $this->trxIdleCallbacks
,
3510 function ( $entry ) use ( $sectionIds ) {
3511 return !in_array( $entry[2], $sectionIds, true );
3514 $this->trxPreCommitCallbacks
= array_filter(
3515 $this->trxPreCommitCallbacks
,
3516 function ( $entry ) use ( $sectionIds ) {
3517 return !in_array( $entry[2], $sectionIds, true );
3520 // Make "on resolution" callbacks owned by this savepoint to perceive a rollback
3521 foreach ( $this->trxEndCallbacks
as $key => $entry ) {
3522 if ( in_array( $entry[2], $sectionIds, true ) ) {
3523 $callback = $entry[0];
3524 $this->trxEndCallbacks
[$key][0] = function () use ( $callback ) {
3525 return $callback( self
::TRIGGER_ROLLBACK
, $this );
3531 final public function setTransactionListener( $name, callable
$callback = null ) {
3533 $this->trxRecurringCallbacks
[$name] = $callback;
3535 unset( $this->trxRecurringCallbacks
[$name] );
3540 * Whether to disable running of post-COMMIT/ROLLBACK callbacks
3542 * This method should not be used outside of Database/LoadBalancer
3544 * @param bool $suppress
3547 final public function setTrxEndCallbackSuppression( $suppress ) {
3548 $this->trxEndCallbacksSuppressed
= $suppress;
3552 * Actually consume and run any "on transaction idle/resolution" callbacks.
3554 * This method should not be used outside of Database/LoadBalancer
3556 * @param int $trigger IDatabase::TRIGGER_* constant
3557 * @return int Number of callbacks attempted
3561 public function runOnTransactionIdleCallbacks( $trigger ) {
3562 if ( $this->trxLevel
) { // sanity
3563 throw new DBUnexpectedError( $this, __METHOD__
. ': a transaction is still open.' );
3566 if ( $this->trxEndCallbacksSuppressed
) {
3571 $autoTrx = $this->getFlag( self
::DBO_TRX
); // automatic begin() enabled?
3572 /** @var Exception $e */
3573 $e = null; // first exception
3574 do { // callbacks may add callbacks :)
3575 $callbacks = array_merge(
3576 $this->trxIdleCallbacks
,
3577 $this->trxEndCallbacks
// include "transaction resolution" callbacks
3579 $this->trxIdleCallbacks
= []; // consumed (and recursion guard)
3580 $this->trxEndCallbacks
= []; // consumed (recursion guard)
3581 foreach ( $callbacks as $callback ) {
3583 list( $phpCallback ) = $callback;
3584 $this->clearFlag( self
::DBO_TRX
); // make each query its own transaction
3586 // @phan-suppress-next-line PhanParamTooManyCallable
3587 call_user_func( $phpCallback, $trigger, $this );
3588 } catch ( Exception
$ex ) {
3589 call_user_func( $this->errorLogger
, $ex );
3591 // Some callbacks may use startAtomic/endAtomic, so make sure
3592 // their transactions are ended so other callbacks don't fail
3593 if ( $this->trxLevel() ) {
3594 $this->rollback( __METHOD__
, self
::FLUSHING_INTERNAL
);
3598 $this->setFlag( self
::DBO_TRX
); // restore automatic begin()
3600 $this->clearFlag( self
::DBO_TRX
); // restore auto-commit
3604 } while ( count( $this->trxIdleCallbacks
) );
3606 if ( $e instanceof Exception
) {
3607 throw $e; // re-throw any first exception
3614 * Actually consume and run any "on transaction pre-commit" callbacks.
3616 * This method should not be used outside of Database/LoadBalancer
3619 * @return int Number of callbacks attempted
3622 public function runOnTransactionPreCommitCallbacks() {
3625 $e = null; // first exception
3626 do { // callbacks may add callbacks :)
3627 $callbacks = $this->trxPreCommitCallbacks
;
3628 $this->trxPreCommitCallbacks
= []; // consumed (and recursion guard)
3629 foreach ( $callbacks as $callback ) {
3632 list( $phpCallback ) = $callback;
3633 $phpCallback( $this );
3634 } catch ( Exception
$ex ) {
3635 ( $this->errorLogger
)( $ex );
3639 } while ( count( $this->trxPreCommitCallbacks
) );
3641 if ( $e instanceof Exception
) {
3642 throw $e; // re-throw any first exception
3649 * Actually run any "transaction listener" callbacks.
3651 * This method should not be used outside of Database/LoadBalancer
3653 * @param int $trigger IDatabase::TRIGGER_* constant
3657 public function runTransactionListenerCallbacks( $trigger ) {
3658 if ( $this->trxEndCallbacksSuppressed
) {
3662 /** @var Exception $e */
3663 $e = null; // first exception
3665 foreach ( $this->trxRecurringCallbacks
as $phpCallback ) {
3667 $phpCallback( $trigger, $this );
3668 } catch ( Exception
$ex ) {
3669 ( $this->errorLogger
)( $ex );
3674 if ( $e instanceof Exception
) {
3675 throw $e; // re-throw any first exception
3680 * Create a savepoint
3682 * This is used internally to implement atomic sections. It should not be
3686 * @param string $identifier Identifier for the savepoint
3687 * @param string $fname Calling function name
3689 protected function doSavepoint( $identifier, $fname ) {
3690 $this->query( 'SAVEPOINT ' . $this->addIdentifierQuotes( $identifier ), $fname );
3694 * Release a savepoint
3696 * This is used internally to implement atomic sections. It should not be
3700 * @param string $identifier Identifier for the savepoint
3701 * @param string $fname Calling function name
3703 protected function doReleaseSavepoint( $identifier, $fname ) {
3704 $this->query( 'RELEASE SAVEPOINT ' . $this->addIdentifierQuotes( $identifier ), $fname );
3708 * Rollback to a savepoint
3710 * This is used internally to implement atomic sections. It should not be
3714 * @param string $identifier Identifier for the savepoint
3715 * @param string $fname Calling function name
3717 protected function doRollbackToSavepoint( $identifier, $fname ) {
3718 $this->query( 'ROLLBACK TO SAVEPOINT ' . $this->addIdentifierQuotes( $identifier ), $fname );
3722 * @param string $fname
3725 private function nextSavepointId( $fname ) {
3726 $savepointId = self
::$SAVEPOINT_PREFIX . ++
$this->trxAtomicCounter
;
3727 if ( strlen( $savepointId ) > 30 ) {
3728 // 30 == Oracle's identifier length limit (pre 12c)
3729 // With a 22 character prefix, that puts the highest number at 99999999.
3730 throw new DBUnexpectedError(
3732 'There have been an excessively large number of atomic sections in a transaction'
3733 . " started by $this->trxFname (at $fname)"
3737 return $savepointId;
3740 final public function startAtomic(
3741 $fname = __METHOD__
, $cancelable = self
::ATOMIC_NOT_CANCELABLE
3743 $savepointId = $cancelable === self
::ATOMIC_CANCELABLE ? self
::$NOT_APPLICABLE : null;
3745 if ( !$this->trxLevel
) {
3746 $this->begin( $fname, self
::TRANSACTION_INTERNAL
); // sets trxAutomatic
3747 // If DBO_TRX is set, a series of startAtomic/endAtomic pairs will result
3748 // in all changes being in one transaction to keep requests transactional.
3749 if ( $this->getFlag( self
::DBO_TRX
) ) {
3750 // Since writes could happen in between the topmost atomic sections as part
3751 // of the transaction, those sections will need savepoints.
3752 $savepointId = $this->nextSavepointId( $fname );
3753 $this->doSavepoint( $savepointId, $fname );
3755 $this->trxAutomaticAtomic
= true;
3757 } elseif ( $cancelable === self
::ATOMIC_CANCELABLE
) {
3758 $savepointId = $this->nextSavepointId( $fname );
3759 $this->doSavepoint( $savepointId, $fname );
3762 $sectionId = new AtomicSectionIdentifier
;
3763 $this->trxAtomicLevels
[] = [ $fname, $sectionId, $savepointId ];
3764 $this->queryLogger
->debug( 'startAtomic: entering level ' .
3765 ( count( $this->trxAtomicLevels
) - 1 ) . " ($fname)" );
3770 final public function endAtomic( $fname = __METHOD__
) {
3771 if ( !$this->trxLevel ||
!$this->trxAtomicLevels
) {
3772 throw new DBUnexpectedError( $this, "No atomic section is open (got $fname)." );
3775 // Check if the current section matches $fname
3776 $pos = count( $this->trxAtomicLevels
) - 1;
3777 list( $savedFname, $sectionId, $savepointId ) = $this->trxAtomicLevels
[$pos];
3778 $this->queryLogger
->debug( "endAtomic: leaving level $pos ($fname)" );
3780 if ( $savedFname !== $fname ) {
3781 throw new DBUnexpectedError(
3783 "Invalid atomic section ended (got $fname but expected $savedFname)."
3787 // Remove the last section (no need to re-index the array)
3788 array_pop( $this->trxAtomicLevels
);
3790 if ( !$this->trxAtomicLevels
&& $this->trxAutomaticAtomic
) {
3791 $this->commit( $fname, self
::FLUSHING_INTERNAL
);
3792 } elseif ( $savepointId !== null && $savepointId !== self
::$NOT_APPLICABLE ) {
3793 $this->doReleaseSavepoint( $savepointId, $fname );
3796 // Hoist callback ownership for callbacks in the section that just ended;
3797 // all callbacks should have an owner that is present in trxAtomicLevels.
3798 $currentSectionId = $this->currentAtomicSectionId();
3799 if ( $currentSectionId ) {
3800 $this->reassignCallbacksForSection( $sectionId, $currentSectionId );
3804 final public function cancelAtomic(
3805 $fname = __METHOD__
, AtomicSectionIdentifier
$sectionId = null
3807 if ( !$this->trxLevel ||
!$this->trxAtomicLevels
) {
3808 throw new DBUnexpectedError( $this, "No atomic section is open (got $fname)." );
3811 $excisedFnames = [];
3812 if ( $sectionId !== null ) {
3813 // Find the (last) section with the given $sectionId
3815 foreach ( $this->trxAtomicLevels
as $i => list( $asFname, $asId, $spId ) ) {
3816 if ( $asId === $sectionId ) {
3821 throw new DBUnexpectedError( $this, "Atomic section not found (for $fname)" );
3823 // Remove all descendant sections and re-index the array
3825 $len = count( $this->trxAtomicLevels
);
3826 for ( $i = $pos +
1; $i < $len; ++
$i ) {
3827 $excisedFnames[] = $this->trxAtomicLevels
[$i][0];
3828 $excisedIds[] = $this->trxAtomicLevels
[$i][1];
3830 $this->trxAtomicLevels
= array_slice( $this->trxAtomicLevels
, 0, $pos +
1 );
3831 $this->modifyCallbacksForCancel( $excisedIds );
3834 // Check if the current section matches $fname
3835 $pos = count( $this->trxAtomicLevels
) - 1;
3836 list( $savedFname, $savedSectionId, $savepointId ) = $this->trxAtomicLevels
[$pos];
3838 if ( $excisedFnames ) {
3839 $this->queryLogger
->debug( "cancelAtomic: canceling level $pos ($savedFname) " .
3840 "and descendants " . implode( ', ', $excisedFnames ) );
3842 $this->queryLogger
->debug( "cancelAtomic: canceling level $pos ($savedFname)" );
3845 if ( $savedFname !== $fname ) {
3846 throw new DBUnexpectedError(
3848 "Invalid atomic section ended (got $fname but expected $savedFname)."
3852 // Remove the last section (no need to re-index the array)
3853 array_pop( $this->trxAtomicLevels
);
3854 $this->modifyCallbacksForCancel( [ $savedSectionId ] );
3856 if ( $savepointId !== null ) {
3857 // Rollback the transaction to the state just before this atomic section
3858 if ( $savepointId === self
::$NOT_APPLICABLE ) {
3859 $this->rollback( $fname, self
::FLUSHING_INTERNAL
);
3861 $this->doRollbackToSavepoint( $savepointId, $fname );
3862 $this->trxStatus
= self
::STATUS_TRX_OK
; // no exception; recovered
3863 $this->trxStatusIgnoredCause
= null;
3865 } elseif ( $this->trxStatus
> self
::STATUS_TRX_ERROR
) {
3866 // Put the transaction into an error state if it's not already in one
3867 $this->trxStatus
= self
::STATUS_TRX_ERROR
;
3868 $this->trxStatusCause
= new DBUnexpectedError(
3870 "Uncancelable atomic section canceled (got $fname)."
3874 $this->affectedRowCount
= 0; // for the sake of consistency
3877 final public function doAtomicSection(
3878 $fname, callable
$callback, $cancelable = self
::ATOMIC_NOT_CANCELABLE
3880 $sectionId = $this->startAtomic( $fname, $cancelable );
3882 $res = $callback( $this, $fname );
3883 } catch ( Exception
$e ) {
3884 $this->cancelAtomic( $fname, $sectionId );
3888 $this->endAtomic( $fname );
3893 final public function begin( $fname = __METHOD__
, $mode = self
::TRANSACTION_EXPLICIT
) {
3894 static $modes = [ self
::TRANSACTION_EXPLICIT
, self
::TRANSACTION_INTERNAL
];
3895 if ( !in_array( $mode, $modes, true ) ) {
3896 throw new DBUnexpectedError( $this, "$fname: invalid mode parameter '$mode'." );
3899 // Protect against mismatched atomic section, transaction nesting, and snapshot loss
3900 if ( $this->trxLevel
) {
3901 if ( $this->trxAtomicLevels
) {
3902 $levels = $this->flatAtomicSectionList();
3903 $msg = "$fname: Got explicit BEGIN while atomic section(s) $levels are open.";
3904 throw new DBUnexpectedError( $this, $msg );
3905 } elseif ( !$this->trxAutomatic
) {
3906 $msg = "$fname: Explicit transaction already active (from {$this->trxFname}).";
3907 throw new DBUnexpectedError( $this, $msg );
3909 $msg = "$fname: Implicit transaction already active (from {$this->trxFname}).";
3910 throw new DBUnexpectedError( $this, $msg );
3912 } elseif ( $this->getFlag( self
::DBO_TRX
) && $mode !== self
::TRANSACTION_INTERNAL
) {
3913 $msg = "$fname: Implicit transaction expected (DBO_TRX set).";
3914 throw new DBUnexpectedError( $this, $msg );
3917 $this->assertHasConnectionHandle();
3919 $this->doBegin( $fname );
3920 $this->trxStatus
= self
::STATUS_TRX_OK
;
3921 $this->trxStatusIgnoredCause
= null;
3922 $this->trxAtomicCounter
= 0;
3923 $this->trxTimestamp
= microtime( true );
3924 $this->trxFname
= $fname;
3925 $this->trxDoneWrites
= false;
3926 $this->trxAutomaticAtomic
= false;
3927 $this->trxAtomicLevels
= [];
3928 $this->trxShortId
= sprintf( '%06x', mt_rand( 0, 0xffffff ) );
3929 $this->trxWriteDuration
= 0.0;
3930 $this->trxWriteQueryCount
= 0;
3931 $this->trxWriteAffectedRows
= 0;
3932 $this->trxWriteAdjDuration
= 0.0;
3933 $this->trxWriteAdjQueryCount
= 0;
3934 $this->trxWriteCallers
= [];
3935 // First SELECT after BEGIN will establish the snapshot in REPEATABLE-READ.
3936 // Get an estimate of the replication lag before any such queries.
3937 $this->trxReplicaLag
= null; // clear cached value first
3938 $this->trxReplicaLag
= $this->getApproximateLagStatus()['lag'];
3939 // T147697: make explicitTrxActive() return true until begin() finishes. This way, no
3940 // caller will think its OK to muck around with the transaction just because startAtomic()
3941 // has not yet completed (e.g. setting trxAtomicLevels).
3942 $this->trxAutomatic
= ( $mode === self
::TRANSACTION_INTERNAL
);
3946 * Issues the BEGIN command to the database server.
3948 * @see Database::begin()
3949 * @param string $fname
3951 protected function doBegin( $fname ) {
3952 $this->query( 'BEGIN', $fname );
3953 $this->trxLevel
= 1;
3956 final public function commit( $fname = __METHOD__
, $flush = self
::FLUSHING_ONE
) {
3957 static $modes = [ self
::FLUSHING_ONE
, self
::FLUSHING_ALL_PEERS
, self
::FLUSHING_INTERNAL
];
3958 if ( !in_array( $flush, $modes, true ) ) {
3959 throw new DBUnexpectedError( $this, "$fname: invalid flush parameter '$flush'." );
3962 if ( $this->trxLevel
&& $this->trxAtomicLevels
) {
3963 // There are still atomic sections open; this cannot be ignored
3964 $levels = $this->flatAtomicSectionList();
3965 throw new DBUnexpectedError(
3967 "$fname: Got COMMIT while atomic sections $levels are still open."
3971 if ( $flush === self
::FLUSHING_INTERNAL ||
$flush === self
::FLUSHING_ALL_PEERS
) {
3972 if ( !$this->trxLevel
) {
3973 return; // nothing to do
3974 } elseif ( !$this->trxAutomatic
) {
3975 throw new DBUnexpectedError(
3977 "$fname: Flushing an explicit transaction, getting out of sync."
3980 } elseif ( !$this->trxLevel
) {
3981 $this->queryLogger
->error(
3982 "$fname: No transaction to commit, something got out of sync." );
3983 return; // nothing to do
3984 } elseif ( $this->trxAutomatic
) {
3985 throw new DBUnexpectedError(
3987 "$fname: Expected mass commit of all peer transactions (DBO_TRX set)."
3991 $this->assertHasConnectionHandle();
3993 $this->runOnTransactionPreCommitCallbacks();
3995 $writeTime = $this->pendingWriteQueryDuration( self
::ESTIMATE_DB_APPLY
);
3996 $this->doCommit( $fname );
3997 $this->trxStatus
= self
::STATUS_TRX_NONE
;
3999 if ( $this->trxDoneWrites
) {
4000 $this->lastWriteTime
= microtime( true );
4001 $this->trxProfiler
->transactionWritingOut(
4003 $this->getDomainID(),
4006 $this->trxWriteAffectedRows
4010 // With FLUSHING_ALL_PEERS, callbacks will be explicitly run later
4011 if ( $flush !== self
::FLUSHING_ALL_PEERS
) {
4012 $this->runOnTransactionIdleCallbacks( self
::TRIGGER_COMMIT
);
4013 $this->runTransactionListenerCallbacks( self
::TRIGGER_COMMIT
);
4018 * Issues the COMMIT command to the database server.
4020 * @see Database::commit()
4021 * @param string $fname
4023 protected function doCommit( $fname ) {
4024 if ( $this->trxLevel
) {
4025 $this->query( 'COMMIT', $fname );
4026 $this->trxLevel
= 0;
4030 final public function rollback( $fname = __METHOD__
, $flush = '' ) {
4031 $trxActive = $this->trxLevel
;
4033 if ( $flush !== self
::FLUSHING_INTERNAL
4034 && $flush !== self
::FLUSHING_ALL_PEERS
4035 && $this->getFlag( self
::DBO_TRX
)
4037 throw new DBUnexpectedError(
4039 "$fname: Expected mass rollback of all peer transactions (DBO_TRX set)."
4044 $this->assertHasConnectionHandle();
4046 $this->doRollback( $fname );
4047 $this->trxStatus
= self
::STATUS_TRX_NONE
;
4048 $this->trxAtomicLevels
= [];
4049 // Estimate the RTT via a query now that trxStatus is OK
4050 $writeTime = $this->pingAndCalculateLastTrxApplyTime();
4052 if ( $this->trxDoneWrites
) {
4053 $this->trxProfiler
->transactionWritingOut(
4055 $this->getDomainID(),
4058 $this->trxWriteAffectedRows
4063 // Clear any commit-dependant callbacks. They might even be present
4064 // only due to transaction rounds, with no SQL transaction being active
4065 $this->trxIdleCallbacks
= [];
4066 $this->trxPreCommitCallbacks
= [];
4068 // With FLUSHING_ALL_PEERS, callbacks will be explicitly run later
4069 if ( $trxActive && $flush !== self
::FLUSHING_ALL_PEERS
) {
4071 $this->runOnTransactionIdleCallbacks( self
::TRIGGER_ROLLBACK
);
4072 } catch ( Exception
$e ) {
4073 // already logged; finish and let LoadBalancer move on during mass-rollback
4076 $this->runTransactionListenerCallbacks( self
::TRIGGER_ROLLBACK
);
4077 } catch ( Exception
$e ) {
4078 // already logged; let LoadBalancer move on during mass-rollback
4081 $this->affectedRowCount
= 0; // for the sake of consistency
4086 * Issues the ROLLBACK command to the database server.
4088 * @see Database::rollback()
4089 * @param string $fname
4091 protected function doRollback( $fname ) {
4092 if ( $this->trxLevel
) {
4093 # Disconnects cause rollback anyway, so ignore those errors
4094 $ignoreErrors = true;
4095 $this->query( 'ROLLBACK', $fname, $ignoreErrors );
4096 $this->trxLevel
= 0;
4100 public function flushSnapshot( $fname = __METHOD__
) {
4101 if ( $this->writesOrCallbacksPending() ||
$this->explicitTrxActive() ) {
4102 // This only flushes transactions to clear snapshots, not to write data
4103 $fnames = implode( ', ', $this->pendingWriteAndCallbackCallers() );
4104 throw new DBUnexpectedError(
4106 "$fname: Cannot flush snapshot because writes are pending ($fnames)."
4110 $this->commit( $fname, self
::FLUSHING_INTERNAL
);
4113 public function explicitTrxActive() {
4114 return $this->trxLevel
&& ( $this->trxAtomicLevels ||
!$this->trxAutomatic
);
4117 public function duplicateTableStructure(
4118 $oldName, $newName, $temporary = false, $fname = __METHOD__
4120 throw new RuntimeException( __METHOD__
. ' is not implemented in descendant class' );
4123 public function listTables( $prefix = null, $fname = __METHOD__
) {
4124 throw new RuntimeException( __METHOD__
. ' is not implemented in descendant class' );
4127 public function listViews( $prefix = null, $fname = __METHOD__
) {
4128 throw new RuntimeException( __METHOD__
. ' is not implemented in descendant class' );
4131 public function timestamp( $ts = 0 ) {
4132 $t = new ConvertibleTimestamp( $ts );
4133 // Let errors bubble up to avoid putting garbage in the DB
4134 return $t->getTimestamp( TS_MW
);
4137 public function timestampOrNull( $ts = null ) {
4138 if ( is_null( $ts ) ) {
4141 return $this->timestamp( $ts );
4145 public function affectedRows() {
4146 return ( $this->affectedRowCount
=== null )
4147 ?
$this->fetchAffectedRowCount() // default to driver value
4148 : $this->affectedRowCount
;
4152 * @return int Number of retrieved rows according to the driver
4154 abstract protected function fetchAffectedRowCount();
4157 * Take the result from a query, and wrap it in a ResultWrapper if
4158 * necessary. Boolean values are passed through as is, to indicate success
4159 * of write queries or failure.
4161 * Once upon a time, Database::query() returned a bare MySQL result
4162 * resource, and it was necessary to call this function to convert it to
4163 * a wrapper. Nowadays, raw database objects are never exposed to external
4164 * callers, so this is unnecessary in external code.
4166 * @param bool|IResultWrapper|resource $result
4167 * @return bool|IResultWrapper
4169 protected function resultObject( $result ) {
4172 } elseif ( $result instanceof ResultWrapper
) {
4174 } elseif ( $result === true ) {
4175 // Successful write query
4178 return new ResultWrapper( $this, $result );
4182 public function ping( &$rtt = null ) {
4183 // Avoid hitting the server if it was hit recently
4184 if ( $this->isOpen() && ( microtime( true ) - $this->lastPing
) < self
::PING_TTL
) {
4185 if ( !func_num_args() ||
$this->rttEstimate
> 0 ) {
4186 $rtt = $this->rttEstimate
;
4187 return true; // don't care about $rtt
4191 // This will reconnect if possible or return false if not
4192 $this->clearFlag( self
::DBO_TRX
, self
::REMEMBER_PRIOR
);
4193 $ok = ( $this->query( self
::PING_QUERY
, __METHOD__
, true ) !== false );
4194 $this->restoreFlags( self
::RESTORE_PRIOR
);
4197 $rtt = $this->rttEstimate
;
4204 * Close any existing (dead) database connection and open a new connection
4206 * @param string $fname
4207 * @return bool True if new connection is opened successfully, false if error
4209 protected function replaceLostConnection( $fname ) {
4210 $this->closeConnection();
4211 $this->opened
= false;
4212 $this->conn
= false;
4214 $this->handleSessionLossPreconnect();
4223 $this->tablePrefix()
4225 $this->lastPing
= microtime( true );
4228 $this->connLogger
->warning(
4229 $fname . ': lost connection to {dbserver}; reconnected',
4231 'dbserver' => $this->getServer(),
4232 'trace' => ( new RuntimeException() )->getTraceAsString()
4235 } catch ( DBConnectionError
$e ) {
4238 $this->connLogger
->error(
4239 $fname . ': lost connection to {dbserver} permanently',
4240 [ 'dbserver' => $this->getServer() ]
4244 $this->handleSessionLossPostconnect();
4249 public function getSessionLagStatus() {
4250 return $this->getRecordedTransactionLagStatus() ?
: $this->getApproximateLagStatus();
4254 * Get the replica DB lag when the current transaction started
4256 * This is useful when transactions might use snapshot isolation
4257 * (e.g. REPEATABLE-READ in innodb), so the "real" lag of that data
4258 * is this lag plus transaction duration. If they don't, it is still
4259 * safe to be pessimistic. This returns null if there is no transaction.
4261 * This returns null if the lag status for this transaction was not yet recorded.
4263 * @return array|null ('lag': seconds or false on error, 'since': UNIX timestamp of BEGIN)
4266 final protected function getRecordedTransactionLagStatus() {
4267 return ( $this->trxLevel
&& $this->trxReplicaLag
!== null )
4268 ?
[ 'lag' => $this->trxReplicaLag
, 'since' => $this->trxTimestamp() ]
4273 * Get a replica DB lag estimate for this server
4275 * @return array ('lag': seconds or false on error, 'since': UNIX timestamp of estimate)
4278 protected function getApproximateLagStatus() {
4280 'lag' => $this->getLBInfo( 'replica' ) ?
$this->getLag() : 0,
4281 'since' => microtime( true )
4286 * Merge the result of getSessionLagStatus() for several DBs
4287 * using the most pessimistic values to estimate the lag of
4288 * any data derived from them in combination
4290 * This is information is useful for caching modules
4292 * @see WANObjectCache::set()
4293 * @see WANObjectCache::getWithSetCallback()
4295 * @param IDatabase $db1
4296 * @param IDatabase|null $db2 [optional]
4297 * @return array Map of values:
4298 * - lag: highest lag of any of the DBs or false on error (e.g. replication stopped)
4299 * - since: oldest UNIX timestamp of any of the DB lag estimates
4300 * - pending: whether any of the DBs have uncommitted changes
4304 public static function getCacheSetOptions( IDatabase
$db1, IDatabase
$db2 = null ) {
4305 $res = [ 'lag' => 0, 'since' => INF
, 'pending' => false ];
4306 foreach ( func_get_args() as $db ) {
4307 /** @var IDatabase $db */
4308 $status = $db->getSessionLagStatus();
4309 if ( $status['lag'] === false ) {
4310 $res['lag'] = false;
4311 } elseif ( $res['lag'] !== false ) {
4312 $res['lag'] = max( $res['lag'], $status['lag'] );
4314 $res['since'] = min( $res['since'], $status['since'] );
4315 $res['pending'] = $res['pending'] ?
: $db->writesPending();
4321 public function getLag() {
4325 public function maxListLen() {
4329 public function encodeBlob( $b ) {
4333 public function decodeBlob( $b ) {
4334 if ( $b instanceof Blob
) {
4340 public function setSessionOptions( array $options ) {
4343 public function sourceFile(
4345 callable
$lineCallback = null,
4346 callable
$resultCallback = null,
4348 callable
$inputCallback = null
4350 Wikimedia\
suppressWarnings();
4351 $fp = fopen( $filename, 'r' );
4352 Wikimedia\restoreWarnings
();
4354 if ( $fp === false ) {
4355 throw new RuntimeException( "Could not open \"{$filename}\".\n" );
4359 $fname = __METHOD__
. "( $filename )";
4363 $error = $this->sourceStream(
4364 $fp, $lineCallback, $resultCallback, $fname, $inputCallback );
4365 } catch ( Exception
$e ) {
4375 public function setSchemaVars( $vars ) {
4376 $this->schemaVars
= $vars;
4379 public function sourceStream(
4381 callable
$lineCallback = null,
4382 callable
$resultCallback = null,
4383 $fname = __METHOD__
,
4384 callable
$inputCallback = null
4386 $delimiterReset = new ScopedCallback(
4387 function ( $delimiter ) {
4388 $this->delimiter
= $delimiter;
4390 [ $this->delimiter
]
4394 while ( !feof( $fp ) ) {
4395 if ( $lineCallback ) {
4396 call_user_func( $lineCallback );
4399 $line = trim( fgets( $fp ) );
4401 if ( $line == '' ) {
4405 if ( $line[0] == '-' && $line[1] == '-' ) {
4413 $done = $this->streamStatementEnd( $cmd, $line );
4417 if ( $done ||
feof( $fp ) ) {
4418 $cmd = $this->replaceVars( $cmd );
4420 if ( $inputCallback ) {
4421 $callbackResult = $inputCallback( $cmd );
4423 if ( is_string( $callbackResult ) ||
!$callbackResult ) {
4424 $cmd = $callbackResult;
4429 $res = $this->query( $cmd, $fname );
4431 if ( $resultCallback ) {
4432 $resultCallback( $res, $this );
4435 if ( $res === false ) {
4436 $err = $this->lastError();
4438 return "Query \"{$cmd}\" failed with error code \"$err\".\n";
4445 ScopedCallback
::consume( $delimiterReset );
4450 * Called by sourceStream() to check if we've reached a statement end
4452 * @param string &$sql SQL assembled so far
4453 * @param string &$newLine New line about to be added to $sql
4454 * @return bool Whether $newLine contains end of the statement
4456 public function streamStatementEnd( &$sql, &$newLine ) {
4457 if ( $this->delimiter
) {
4459 $newLine = preg_replace(
4460 '/' . preg_quote( $this->delimiter
, '/' ) . '$/', '', $newLine );
4461 if ( $newLine != $prev ) {
4470 * Database independent variable replacement. Replaces a set of variables
4471 * in an SQL statement with their contents as given by $this->getSchemaVars().
4473 * Supports '{$var}' `{$var}` and / *$var* / (without the spaces) style variables.
4475 * - '{$var}' should be used for text and is passed through the database's
4477 * - `{$var}` should be used for identifiers (e.g. table and database names).
4478 * It is passed through the database's addIdentifierQuotes method which
4479 * can be overridden if the database uses something other than backticks.
4480 * - / *_* / or / *$wgDBprefix* / passes the name that follows through the
4481 * database's tableName method.
4482 * - / *i* / passes the name that follows through the database's indexName method.
4483 * - In all other cases, / *$var* / is left unencoded. Except for table options,
4484 * its use should be avoided. In 1.24 and older, string encoding was applied.
4486 * @param string $ins SQL statement to replace variables in
4487 * @return string The new SQL statement with variables replaced
4489 protected function replaceVars( $ins ) {
4490 $vars = $this->getSchemaVars();
4491 return preg_replace_callback(
4493 /\* (\$wgDBprefix|[_i]) \*/ (\w*) | # 1-2. tableName, indexName
4494 \'\{\$ (\w+) }\' | # 3. addQuotes
4495 `\{\$ (\w+) }` | # 4. addIdentifierQuotes
4496 /\*\$ (\w+) \*/ # 5. leave unencoded
4498 function ( $m ) use ( $vars ) {
4499 // Note: Because of <https://bugs.php.net/bug.php?id=51881>,
4500 // check for both nonexistent keys *and* the empty string.
4501 if ( isset( $m[1] ) && $m[1] !== '' ) {
4502 if ( $m[1] === 'i' ) {
4503 return $this->indexName( $m[2] );
4505 return $this->tableName( $m[2] );
4507 } elseif ( isset( $m[3] ) && $m[3] !== '' && array_key_exists( $m[3], $vars ) ) {
4508 return $this->addQuotes( $vars[$m[3]] );
4509 } elseif ( isset( $m[4] ) && $m[4] !== '' && array_key_exists( $m[4], $vars ) ) {
4510 return $this->addIdentifierQuotes( $vars[$m[4]] );
4511 } elseif ( isset( $m[5] ) && $m[5] !== '' && array_key_exists( $m[5], $vars ) ) {
4512 return $vars[$m[5]];
4522 * Get schema variables. If none have been set via setSchemaVars(), then
4523 * use some defaults from the current object.
4527 protected function getSchemaVars() {
4528 if ( $this->schemaVars
) {
4529 return $this->schemaVars
;
4531 return $this->getDefaultSchemaVars();
4536 * Get schema variables to use if none have been set via setSchemaVars().
4538 * Override this in derived classes to provide variables for tables.sql
4539 * and SQL patch files.
4543 protected function getDefaultSchemaVars() {
4547 public function lockIsFree( $lockName, $method ) {
4548 // RDBMs methods for checking named locks may or may not count this thread itself.
4549 // In MySQL, IS_FREE_LOCK() returns 0 if the thread already has the lock. This is
4550 // the behavior choosen by the interface for this method.
4551 return !isset( $this->namedLocksHeld
[$lockName] );
4554 public function lock( $lockName, $method, $timeout = 5 ) {
4555 $this->namedLocksHeld
[$lockName] = 1;
4560 public function unlock( $lockName, $method ) {
4561 unset( $this->namedLocksHeld
[$lockName] );
4566 public function getScopedLockAndFlush( $lockKey, $fname, $timeout ) {
4567 if ( $this->writesOrCallbacksPending() ) {
4568 // This only flushes transactions to clear snapshots, not to write data
4569 $fnames = implode( ', ', $this->pendingWriteAndCallbackCallers() );
4570 throw new DBUnexpectedError(
4572 "$fname: Cannot flush pre-lock snapshot because writes are pending ($fnames)."
4576 if ( !$this->lock( $lockKey, $fname, $timeout ) ) {
4580 $unlocker = new ScopedCallback( function () use ( $lockKey, $fname ) {
4581 if ( $this->trxLevel() ) {
4582 // There is a good chance an exception was thrown, causing any early return
4583 // from the caller. Let any error handler get a chance to issue rollback().
4584 // If there isn't one, let the error bubble up and trigger server-side rollback.
4585 $this->onTransactionResolution(
4586 function () use ( $lockKey, $fname ) {
4587 $this->unlock( $lockKey, $fname );
4592 $this->unlock( $lockKey, $fname );
4596 $this->commit( $fname, self
::FLUSHING_INTERNAL
);
4601 public function namedLocksEnqueue() {
4605 public function tableLocksHaveTransactionScope() {
4609 final public function lockTables( array $read, array $write, $method ) {
4610 if ( $this->writesOrCallbacksPending() ) {
4611 throw new DBUnexpectedError( $this, "Transaction writes or callbacks still pending." );
4614 if ( $this->tableLocksHaveTransactionScope() ) {
4615 $this->startAtomic( $method );
4618 return $this->doLockTables( $read, $write, $method );
4622 * Helper function for lockTables() that handles the actual table locking
4624 * @param array $read Array of tables to lock for read access
4625 * @param array $write Array of tables to lock for write access
4626 * @param string $method Name of caller
4629 protected function doLockTables( array $read, array $write, $method ) {
4633 final public function unlockTables( $method ) {
4634 if ( $this->tableLocksHaveTransactionScope() ) {
4635 $this->endAtomic( $method );
4637 return true; // locks released on COMMIT/ROLLBACK
4640 return $this->doUnlockTables( $method );
4644 * Helper function for unlockTables() that handles the actual table unlocking
4646 * @param string $method Name of caller
4649 protected function doUnlockTables( $method ) {
4655 * @param string $tableName
4656 * @param string $fName
4657 * @return bool|IResultWrapper
4660 public function dropTable( $tableName, $fName = __METHOD__
) {
4661 if ( !$this->tableExists( $tableName, $fName ) ) {
4664 $sql = "DROP TABLE " . $this->tableName( $tableName ) . " CASCADE";
4666 return $this->query( $sql, $fName );
4669 public function getInfinity() {
4673 public function encodeExpiry( $expiry ) {
4674 return ( $expiry == '' ||
$expiry == 'infinity' ||
$expiry == $this->getInfinity() )
4675 ?
$this->getInfinity()
4676 : $this->timestamp( $expiry );
4679 public function decodeExpiry( $expiry, $format = TS_MW
) {
4680 if ( $expiry == '' ||
$expiry == 'infinity' ||
$expiry == $this->getInfinity() ) {
4684 return ConvertibleTimestamp
::convert( $format, $expiry );
4687 public function setBigSelects( $value = true ) {
4691 public function isReadOnly() {
4692 return ( $this->getReadOnlyReason() !== false );
4696 * @return string|bool Reason this DB is read-only or false if it is not
4698 protected function getReadOnlyReason() {
4699 $reason = $this->getLBInfo( 'readOnlyReason' );
4701 return is_string( $reason ) ?
$reason : false;
4704 public function setTableAliases( array $aliases ) {
4705 $this->tableAliases
= $aliases;
4708 public function setIndexAliases( array $aliases ) {
4709 $this->indexAliases
= $aliases;
4717 protected function hasFlags( $field, $flags ) {
4718 return ( ( $field & $flags ) === $flags );
4722 * Get the underlying binding connection handle
4724 * Makes sure the connection resource is set (disconnects and ping() failure can unset it).
4725 * This catches broken callers than catch and ignore disconnection exceptions.
4726 * Unlike checking isOpen(), this is safe to call inside of open().
4729 * @throws DBUnexpectedError
4732 protected function getBindingHandle() {
4733 if ( !$this->conn
) {
4734 throw new DBUnexpectedError(
4736 'DB connection was already closed or the connection dropped.'
4747 public function __toString() {
4748 return (string)$this->conn
;
4752 * Make sure that copies do not share the same client binding handle
4753 * @throws DBConnectionError
4755 public function __clone() {
4756 $this->connLogger
->warning(
4757 "Cloning " . static::class . " is not recommended; forking connection:\n" .
4758 ( new RuntimeException() )->getTraceAsString()
4761 if ( $this->isOpen() ) {
4762 // Open a new connection resource without messing with the old one
4763 $this->opened
= false;
4764 $this->conn
= false;
4765 $this->trxEndCallbacks
= []; // don't copy
4766 $this->handleSessionLossPreconnect(); // no trx or locks anymore
4773 $this->tablePrefix()
4775 $this->lastPing
= microtime( true );
4780 * Called by serialize. Throw an exception when DB connection is serialized.
4781 * This causes problems on some database engines because the connection is
4782 * not restored on unserialize.
4784 public function __sleep() {
4785 throw new RuntimeException( 'Database serialization may cause problems, since ' .
4786 'the connection is not restored on wakeup.' );
4790 * Run a few simple sanity checks and close dangling connections
4792 public function __destruct() {
4793 if ( $this->trxLevel
&& $this->trxDoneWrites
) {
4794 trigger_error( "Uncommitted DB writes (transaction from {$this->trxFname})." );
4797 $danglingWriters = $this->pendingWriteAndCallbackCallers();
4798 if ( $danglingWriters ) {
4799 $fnames = implode( ', ', $danglingWriters );
4800 trigger_error( "DB transaction writes or callbacks still pending ($fnames)." );
4803 if ( $this->conn
) {
4804 // Avoid connection leaks for sanity. Normally, resources close at script completion.
4805 // The connection might already be closed in zend/hhvm by now, so suppress warnings.
4806 Wikimedia\
suppressWarnings();
4807 $this->closeConnection();
4808 Wikimedia\restoreWarnings
();
4809 $this->conn
= false;
4810 $this->opened
= false;
4816 * @deprecated since 1.28
4818 class_alias( Database
::class, 'DatabaseBase' );
4821 * @deprecated since 1.29
4823 class_alias( Database
::class, 'Database' );