Class for managing the deferred updates. More...

Collaboration diagram for DeferredUpdates:

Static Public Member Functions
static	addCallableUpdate ( $callable, $stage=self::POSTSEND, IDatabase $dbw=null)
	Add a callable update.

static	addUpdate (DeferrableUpdate $update, $stage=self::POSTSEND)
	Add an update to the deferred list to be run later by execute()

static	clearPendingUpdates ()
	Clear all pending updates without performing them.

static	doUpdates ( $mode='run', $stage=self::ALL)
	Do any deferred updates and clear the list.

static	pendingUpdatesCount ()

static	setImmediateMode ( $value)

static	tryOpportunisticExecute ( $mode='run')
	Run all deferred updates immediately if there are no DB writes active.

Public Attributes
const	ALL = 0

const	BIG_QUEUE_SIZE = 100

const	POSTSEND = 2

const	PRESEND = 1

Static Protected Member Functions
static	execute (array &$queue, $mode, $stage)
	Immediately run/queue a list of updates.

Static Private Member Functions
static	areDatabaseTransactionsActive ()

static	enqueueUpdates (array $updates)
	Enqueue a job for each EnqueueableDataUpdate item and return the other items.

static	push (array &$queue, DeferrableUpdate $update)

static	runUpdate (DeferrableUpdate $update, LBFactory $lbFactory, $stage)

Static Private Attributes
static array null	$executeContext
	Information about the current execute() call or null if not running.

static DeferrableUpdate[]	$postSendUpdates = []
	Updates to be deferred until after request end.

static DeferrableUpdate[]	$preSendUpdates = []
	Updates to be deferred until before request end.

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, updates run immediately if no DB writes are pending. Otherwise, they run when:

a) Any waitForReplication() call if no writes are pending on any DB
b) A commit happens on Maintenance::getDB( DB_MASTER ) if no writes are pending on any DB
c) EnqueueableDataUpdate tasks may enqueue on commit of Maintenance::getDB( DB_MASTER )
d) At the completion of Maintenance::execute()

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 50 of file DeferredUpdates.php.

Member Function Documentation

◆ addCallableUpdate()

static DeferredUpdates::addCallableUpdate	(		$callable,
			$stage = `self::POSTSEND`,
		IDatabase	$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
integer	$stage	DeferredUpdates constant (PRESEND or POSTSEND) (since 1.27)
IDatabase \| null	$dbw	Abort if this DB is rolled back [optional] (since 1.28)

Definition at line 105 of file DeferredUpdates.php.

References wfGetCaller().

Referenced by MediaWiki\Logger\Monolog\BufferHandler\handle().

◆ addUpdate()

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

static

Add an update to the deferred list to be run later by execute()

In CLI mode, callback magic will also be used to run updates when safe

Parameters

DeferrableUpdate	$update	Some object that implements doUpdate()
integer	$stage	DeferredUpdates constant (PRESEND or POSTSEND) (since 1.27)

Definition at line 73 of file DeferredUpdates.php.

References $wgCommandLineMode, and global.

◆ areDatabaseTransactionsActive()

static DeferredUpdates::areDatabaseTransactionsActive ( )

staticprivate

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

Definition at line 342 of file DeferredUpdates.php.

References $lbFactory, IDatabase\explicitTrxActive(), LoadBalancer\forEachOpenMasterConnection(), use, and IDatabase\writesOrCallbacksPending().

◆ 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 334 of file DeferredUpdates.php.

◆ doUpdates()

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

static

Do any deferred updates and clear the list.

Parameters

string	$mode	Use "enqueue" to use the job queue when possible [Default: "run"]
integer	$stage	DeferredUpdates constant (PRESEND, POSTSEND, or ALL) (since 1.27)

Definition at line 117 of file DeferredUpdates.php.

References execute().

◆ enqueueUpdates()

static DeferredUpdates::enqueueUpdates ( array $updates )

staticprivate

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

Parameters

DeferrableUpdate[] $updates A list of deferred update instances

Returns: DeferrableUpdate[] Remaining updates that do not support being queued

Definition at line 307 of file DeferredUpdates.php.

References as, and JobQueueGroup\singleton().

◆ execute()

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

staticprotected

Immediately run/queue a list of updates.

Parameters

DeferrableUpdate[]	&$queue	List of DeferrableUpdate objects
string	$mode	Use "enqueue" to use the job queue when possible
integer	$stage	Class constant (PRESEND, POSTSEND) (since 1.28)

Exceptions

ErrorPageError	Happens on top-level calls
Exception	Happens on second-level calls

Definition at line 166 of file DeferredUpdates.php.

References $e, $lbFactory, $name, $queue, $services, as, RequestContext\getMain(), and key.

◆ pendingUpdatesCount()

static DeferredUpdates::pendingUpdatesCount ( )

static

Returns: integer Number of enqueued updates

Since: 1.28

Definition at line 326 of file DeferredUpdates.php.

◆ push()

static DeferredUpdates::push	(	array &	$queue,
		DeferrableUpdate	$update
	)

staticprivate

Parameters

DeferrableUpdate[]	$queue
DeferrableUpdate	$update

Definition at line 142 of file DeferredUpdates.php.

References $queue.

◆ runUpdate()

static DeferredUpdates::runUpdate	(	DeferrableUpdate	$update,
		LBFactory	$lbFactory,
			$stage
	)

staticprivate

Parameters

DeferrableUpdate	$update
LBFactory	$lbFactory
integer	$stage

Returns: ErrorPageError|null

Definition at line 251 of file DeferredUpdates.php.

References $e, $lbFactory, and DeferrableUpdate\doUpdate().

◆ setImmediateMode()

static DeferredUpdates::setImmediateMode ( $value )

static

Parameters

bool $value Whether to just immediately run updates in addUpdate()

Since: 1.28

Deprecated:: 1.29 Causes issues in Web-executed jobs - see T165714 and T100085.

Definition at line 134 of file DeferredUpdates.php.

References wfDeprecated().

◆ tryOpportunisticExecute()

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

static

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

If $mode is 'run' but there are busy databates, EnqueueableDataUpdate tasks will be enqueued anyway for the sake of progress.

Parameters

string $mode Use "enqueue" to use the job queue when possible

Returns: bool Whether updates were allowed to run

Since: 1.28

Definition at line 279 of file DeferredUpdates.php.

Member Data Documentation

◆ $executeContext

array null DeferredUpdates::$executeContext

staticprivate

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

Definition at line 63 of file DeferredUpdates.php.

◆ $postSendUpdates

DeferrableUpdate [] DeferredUpdates::$postSendUpdates = []

staticprivate

Updates to be deferred until after request end.

Definition at line 54 of file DeferredUpdates.php.

◆ $preSendUpdates

DeferrableUpdate [] DeferredUpdates::$preSendUpdates = []

staticprivate

Updates to be deferred until before request end.

Definition at line 52 of file DeferredUpdates.php.

◆ ALL

const DeferredUpdates::ALL = 0

Definition at line 56 of file DeferredUpdates.php.

◆ BIG_QUEUE_SIZE

const DeferredUpdates::BIG_QUEUE_SIZE = 100

Definition at line 60 of file DeferredUpdates.php.

◆ POSTSEND

const DeferredUpdates::POSTSEND = 2

Definition at line 58 of file DeferredUpdates.php.

◆ PRESEND

const DeferredUpdates::PRESEND = 1

Definition at line 57 of file DeferredUpdates.php.

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

includes/deferred/DeferredUpdates.php

Static Public Member Functions

Public Attributes

Static Protected Member Functions

Static Private Member Functions

Static Private Attributes

Detailed Description

Member Function Documentation

◆ addCallableUpdate()

◆ addUpdate()

◆ areDatabaseTransactionsActive()

◆ clearPendingUpdates()

◆ doUpdates()

◆ enqueueUpdates()

◆ execute()

◆ pendingUpdatesCount()

◆ push()

◆ runUpdate()

◆ setImmediateMode()

◆ tryOpportunisticExecute()

Member Data Documentation

◆ $executeContext

◆ $postSendUpdates

◆ $preSendUpdates

◆ ALL

◆ BIG_QUEUE_SIZE

◆ POSTSEND

◆ PRESEND