MediaWiki  1.34.0
DeferredUpdates Class Reference

Class for managing the deferred updates. More...

Collaboration diagram for DeferredUpdates:

Static Public Member Functions

static addCallableUpdate ( $callable, $stage=self::POSTSEND, $dbw=null)
 Add a callable update. More...
 
static addUpdate (DeferrableUpdate $update, $stage=self::POSTSEND)
 Add an update to the deferred list to be run later by execute() More...
 
static attemptUpdate (DeferrableUpdate $update, ILBFactory $lbFactory)
 Attempt to run an update with the appropriate transaction round state it expects. More...
 
static clearPendingUpdates ()
 Clear all pending updates without performing them. More...
 
static doUpdates ( $mode='run', $stage=self::ALL)
 Do any deferred updates and clear the list. More...
 
static getPendingUpdates ( $stage=self::ALL)
 
static pendingUpdatesCount ()
 
static tryOpportunisticExecute ( $mode='run')
 Run all deferred updates immediately if there are no DB writes active. More...
 

Public Attributes

const ALL = 0
 
const BIG_QUEUE_SIZE = 100
 
const POSTSEND = 2
 
const PRESEND = 1
 

Static Protected Member Functions

static handleUpdateQueue (array &$queue, $mode, $stage)
 Immediately run or enqueue a list of updates. More...
 

Static Private Member Functions

static areDatabaseTransactionsActive ()
 
static enqueueUpdates (array $updates)
 Enqueue a job for each EnqueueableDataUpdate item and return the other items. More...
 
static jobify (EnqueueableDataUpdate $update, LBFactory $lbFactory, LoggerInterface $logger, StatsdDataFactoryInterface $stats, $httpMethod)
 Push a task into the job queue system and catch/log any exceptions. More...
 
static push (array &$queue, DeferrableUpdate $update)
 
static run (DeferrableUpdate $update, LBFactory $lbFactory, LoggerInterface $logger, StatsdDataFactoryInterface $stats, $httpMethod)
 Run a task and catch/log any exceptions. More...
 

Static Private Attributes

static array null $executeContext
 Information about the current execute() call or null if not running. More...
 
static DeferrableUpdate[] $postSendUpdates = []
 Updates to be deferred until after request end. More...
 
static DeferrableUpdate[] $preSendUpdates = []
 Updates to be deferred until before request end. More...
 

Detailed Description

Class for managing the deferred updates.

In web request mode, deferred updates can be run at the end of the request, either before or after the HTTP response has been sent. In either case, they run after the DB commit step. If an update runs after the response is sent, it will not block clients. If sent before, it will run synchronously. These two modes are defined via PRESEND and POSTSEND constants, the latter being the default for addUpdate() and addCallableUpdate().

Updates that work through this system will be more likely to complete by the time the client makes their next request after this one than with the JobQueue system.

In CLI mode, deferred updates will run:

  • a) During DeferredUpdates::addUpdate if no LBFactory DB handles have writes pending
  • b) On commit of an LBFactory DB handle if no other such handles have writes pending
  • c) During an LBFactory::waitForReplication call if no LBFactory DBs have writes pending
  • d) When the queue is large and an LBFactory DB handle commits (EnqueueableDataUpdate only)
  • e) At the completion of Maintenance::execute()
See also
Maintenance::setLBFactoryTriggers

When updates are deferred, they go into one two FIFO "top-queues" (one for pre-send and one for post-send). Updates enqueued during doUpdate() of a "top" update go into the "sub-queue" for that update. After that method finishes, the sub-queue is run until drained. This continues for each top-queue job until the entire top queue is drained. This happens for the pre-send top-queue, and later on, the post-send top-queue, in execute().

Since
1.19

Definition at line 62 of file DeferredUpdates.php.

Member Function Documentation

◆ addCallableUpdate()

static DeferredUpdates::addCallableUpdate (   $callable,
  $stage = self::POSTSEND,
  $dbw = null 
)
static

Add a callable update.

In a lot of cases, we just need a callback/closure, defining a new DeferrableUpdate object is not necessary

See also
MWCallableUpdate::__construct()
Parameters
callable$callable
int$stageDeferredUpdates constant (PRESEND or POSTSEND) (since 1.27)
IDatabase | IDatabase[] | null$dbwAbort if this DB is rolled back optional

Definition at line 124 of file DeferredUpdates.php.

References addUpdate(), and wfGetCaller().

Referenced by MediaWiki\Auth\AuthManager\autoCreateUser(), MediaWiki\Auth\LocalPasswordPrimaryAuthenticationProvider\beginPrimaryAuthentication(), SpecialEditWatchlist\cleanupWatchlist(), User\clearNotification(), FileBackendMultiWrite\doDirectoryOp(), LinksDeletionUpdate\doIncrementalUpdate(), FileBackendMultiWrite\doOperationsInternal(), FileBackendMultiWrite\doQuickOperationsInternal(), MediaWiki\Storage\DerivedPageDataUpdater\doUpdates(), WikiPage\doViewUpdates(), EditPage\edit(), RollbackAction\enableTransactionalTimelimit(), ApiRollback\execute(), MovePageForm\execute(), MediaWiki\Logger\Monolog\BufferHandler\handle(), Category\initialize(), UserGroupMembership\insert(), WikiPage\insertRedirect(), LocalFile\maybeUpgradeRow(), RecentChange\notifyEdit(), RecentChange\notifyNew(), WikiPage\onArticleEdit(), ManualLogEntry\publish(), WikiPage\purgeInterwikiCheckKey(), MediaWiki\Session\SessionBackend\save(), SpecialSearch\saveNamespaces(), MediaWiki\Storage\PageUpdater\saveRevision(), Pingback\schedulePingback(), RevDelList\setVisibility(), MediaWiki\Block\BlockManager\trackBlockWithCookie(), WikiPage\updateCategoryCounts(), WatchedItemStore\updateNotificationTimestamp(), and EditPage\updateWatchlist().

◆ addUpdate()

static DeferredUpdates::addUpdate ( DeferrableUpdate  $update,
  $stage = self::POSTSEND 
)
static

◆ areDatabaseTransactionsActive()

static DeferredUpdates::areDatabaseTransactionsActive ( )
staticprivate
Returns
bool If a transaction round is active or connection is not ready for commit()

Definition at line 479 of file DeferredUpdates.php.

References Wikimedia\Rdbms\IDatabase\explicitTrxActive(), Wikimedia\Rdbms\LoadBalancer\forEachOpenMasterConnection(), and Wikimedia\Rdbms\IDatabase\writesOrCallbacksPending().

◆ attemptUpdate()

static DeferredUpdates::attemptUpdate ( DeferrableUpdate  $update,
ILBFactory  $lbFactory 
)
static

Attempt to run an update with the appropriate transaction round state it expects.

DeferredUpdate classes that wrap the execution of bundles of other DeferredUpdate instances can use this method to run the updates. Any such wrapper class should always use TRX_ROUND_ABSENT itself.

Parameters
DeferrableUpdate$update
ILBFactory$lbFactory
Since
1.34

Definition at line 356 of file DeferredUpdates.php.

References Wikimedia\Rdbms\ILBFactory\beginMasterChanges(), Wikimedia\Rdbms\ILBFactory\commitMasterChanges(), DeferrableUpdate\doUpdate(), Wikimedia\Rdbms\ILBFactory\getEmptyTransactionTicket(), and Wikimedia\Rdbms\ILBFactory\hasTransactionRound().

Referenced by MediaWiki\Storage\DerivedPageDataUpdater\doSecondaryDataUpdates(), and run().

◆ clearPendingUpdates()

static DeferredUpdates::clearPendingUpdates ( )
static

Clear all pending updates without performing them.

Generally, you don't want or need to call this. Unit tests need it though.

Definition at line 471 of file DeferredUpdates.php.

◆ doUpdates()

static DeferredUpdates::doUpdates (   $mode = 'run',
  $stage = self::ALL 
)
static

Do any deferred updates and clear the list.

If $stage is self::ALL then the queue of PRESEND updates will be resolved, followed by the queue of POSTSEND updates

Parameters
string$modeUse "enqueue" to use the job queue when possible [Default: "run"]
int$stageDeferredUpdates constant (PRESEND, POSTSEND, or ALL) (since 1.27)

Definition at line 139 of file DeferredUpdates.php.

References ALL, and handleUpdateQueue().

Referenced by JobRunner\executeJob(), RefreshLinks\fixLinksFromArticle(), NamespaceDupes\mergePage(), MediaWiki\preOutputCommit(), MediaWiki\restInPeace(), and tryOpportunisticExecute().

◆ enqueueUpdates()

static DeferredUpdates::enqueueUpdates ( array  $updates)
staticprivate

Enqueue a job for each EnqueueableDataUpdate item and return the other items.

Parameters
DeferrableUpdate[]$updatesA list of deferred update instances
Returns
DeferrableUpdate[] Remaining updates that do not support being queued

Definition at line 427 of file DeferredUpdates.php.

References JobQueueGroup\singleton().

Referenced by tryOpportunisticExecute().

◆ getPendingUpdates()

static DeferredUpdates::getPendingUpdates (   $stage = self::ALL)
static
Parameters
int$stageDeferredUpdates constant (PRESEND, POSTSEND, or ALL)
Returns
DeferrableUpdate[]
Since
1.29

Definition at line 456 of file DeferredUpdates.php.

◆ handleUpdateQueue()

static DeferredUpdates::handleUpdateQueue ( array &  $queue,
  $mode,
  $stage 
)
staticprotected

Immediately run or enqueue a list of updates.

Parameters
DeferrableUpdate[]&$queueList of DeferrableUpdate objects
string$modeEither "run" or "enqueue" (to use the job queue when possible)
int$stageClass constant (PRESEND, POSTSEND) (since 1.28)
Exceptions
ErrorPageErrorHappens on top-level calls
ExceptionHappens on second-level calls

Definition at line 187 of file DeferredUpdates.php.

References $queue, RequestContext\getMain(), jobify(), and run().

Referenced by doUpdates().

◆ jobify()

static DeferredUpdates::jobify ( EnqueueableDataUpdate  $update,
LBFactory  $lbFactory,
LoggerInterface  $logger,
StatsdDataFactoryInterface  $stats,
  $httpMethod 
)
staticprivate

Push a task into the job queue system and catch/log any exceptions.

Parameters
EnqueueableDataUpdate$update
LBFactory$lbFactory
LoggerInterface$logger
StatsdDataFactoryInterface$stats
string$httpMethod

Definition at line 315 of file DeferredUpdates.php.

References EnqueueableDataUpdate\getAsJobSpecification(), Wikimedia\Rdbms\LBFactory\rollbackMasterChanges(), and JobQueueGroup\singleton().

Referenced by handleUpdateQueue().

◆ pendingUpdatesCount()

static DeferredUpdates::pendingUpdatesCount ( )
static
Returns
int Number of enqueued updates
Since
1.28

Definition at line 447 of file DeferredUpdates.php.

Referenced by tryOpportunisticExecute().

◆ push()

static DeferredUpdates::push ( array &  $queue,
DeferrableUpdate  $update 
)
staticprivate
Parameters
DeferrableUpdate[]$queue
DeferrableUpdate$update

Definition at line 158 of file DeferredUpdates.php.

References $queue.

Referenced by addUpdate().

◆ run()

static DeferredUpdates::run ( DeferrableUpdate  $update,
LBFactory  $lbFactory,
LoggerInterface  $logger,
StatsdDataFactoryInterface  $stats,
  $httpMethod 
)
staticprivate

Run a task and catch/log any exceptions.

Parameters
DeferrableUpdate$update
LBFactory$lbFactory
LoggerInterface$logger
StatsdDataFactoryInterface$stats
string$httpMethod
Returns
Exception|Throwable|null

Definition at line 268 of file DeferredUpdates.php.

References attemptUpdate(), and Wikimedia\Rdbms\LBFactory\rollbackMasterChanges().

Referenced by handleUpdateQueue().

◆ tryOpportunisticExecute()

static DeferredUpdates::tryOpportunisticExecute (   $mode = 'run')
static

Run all deferred updates immediately if there are no DB writes active.

If there are many deferred updates pending, $mode is 'run', and there are still busy LBFactory database handles, then any EnqueueableDataUpdate tasks might be enqueued as jobs to be executed later.

Parameters
string$modeUse "enqueue" to use the job queue when possible
Returns
bool Whether updates were allowed to run
Since
1.28

Definition at line 399 of file DeferredUpdates.php.

References doUpdates(), enqueueUpdates(), and pendingUpdatesCount().

Referenced by addUpdate(), and Maintenance\setLBFactoryTriggers().

Member Data Documentation

◆ $executeContext

array null DeferredUpdates::$executeContext
staticprivate

Information about the current execute() call or null if not running.

Definition at line 75 of file DeferredUpdates.php.

◆ $postSendUpdates

DeferrableUpdate [] DeferredUpdates::$postSendUpdates = []
staticprivate

Updates to be deferred until after request end.

Definition at line 66 of file DeferredUpdates.php.

◆ $preSendUpdates

DeferrableUpdate [] DeferredUpdates::$preSendUpdates = []
staticprivate

Updates to be deferred until before request end.

Definition at line 64 of file DeferredUpdates.php.

◆ ALL

const DeferredUpdates::ALL = 0

Definition at line 68 of file DeferredUpdates.php.

Referenced by doUpdates().

◆ BIG_QUEUE_SIZE

const DeferredUpdates::BIG_QUEUE_SIZE = 100

Definition at line 72 of file DeferredUpdates.php.

◆ POSTSEND

◆ PRESEND


The documentation for this class was generated from the following file: