Functions to get cache objects. More...

Collaboration diagram for ObjectCache:

[legend]

Static Public Member Functions
static	clear ()
	Clear all the cached instances. More...

static	getInstance ( $id)
	Get a cached instance of the specified type of cache object. More...

static	getLocalClusterInstance ()
	Get the main cluster-local cache object. More...

static	getLocalServerInstance ( $fallback=CACHE_NONE)
	Factory function for CACHE_ACCEL (referenced from configuration) More...

static	isDatabaseId ( $id)
	Determine whether a config ID would access the database. More...

static	makeLocalServerCache ()
	Create a new BagOStuff instance for local-server caching. More...

static	newAnything ( $params)
	Factory function for CACHE_ANYTHING (referenced by configuration) More...

static	newFromParams (array $params, MediaWikiServices $services=null)
	Create a new cache object from parameters. More...

Static Public Attributes
static BagOStuff[]	$instances = []
	Map of (id => BagOStuff) More...

static string	$localServerCacheClass

Detailed Description

Functions to get cache objects.

The word "cache" has two main dictionary meanings, and both are used in this factory class. They are:

a) Cache (the computer science definition). A place to store copies or computations on existing data for higher access speeds.
b) Storage. A place to store lightweight data that is not canonically stored anywhere else (e.g. a "hoard" of objects).

Primary entry points:

ObjectCache::getLocalServerInstance( $fallbackType ) Purpose: Memory cache for very hot keys. Stored only on the individual web server (typically APC or APCu for web requests, and EmptyBagOStuff in CLI mode). Not replicated to the other servers.
ObjectCache::getLocalClusterInstance() Purpose: Memory storage for per-cluster coordination and tracking. A typical use case would be a rate limit counter or cache regeneration mutex. Stored centrally within the local data-center. Not replicated to other DCs. Configured by $wgMainCacheType.
ObjectCache::getInstance( $cacheType ) Purpose: Special cases (like tiered memory/disk caches). Get a specific cache type by key in $wgObjectCaches.

All the above BagOStuff cache instances have their makeKey() method scoped to the current wiki ID. Use makeGlobalKey() to avoid this scoping when using keys that need to be shared amongst wikis.

Definition at line 66 of file ObjectCache.php.

Member Function Documentation

◆ clear()

static ObjectCache::clear ( )

static

Clear all the cached instances.

Definition at line 349 of file ObjectCache.php.

Referenced by MediaWiki\MediaWikiServices\disableStorage(), and MediaWiki\Maintenance\ForkController\prepareEnvironment().

◆ getInstance()

static ObjectCache::getInstance ( $id )

static

Get a cached instance of the specified type of cache object.

Parameters

string | int $id A key in $wgObjectCaches.

Returns: BagOStuff

Definition at line 82 of file ObjectCache.php.

Referenced by MediaWiki\Session\SessionManager\__construct(), SpecialVersion\getCreditsForExtension(), getLocalServerInstance(), LanguageConverter\loadTables(), and newAnything().

◆ getLocalClusterInstance()

static ObjectCache::getLocalClusterInstance ( )

static

Get the main cluster-local cache object.

Since: 1.27

Returns: BagOStuff

Definition at line 316 of file ObjectCache.php.

Referenced by MediaWiki\Auth\ThrottlePreAuthenticationProvider\__construct(), MediaWiki\Auth\Throttler\__construct(), MediaWiki\Auth\AuthManager\autoCreateUser(), ResetAuthenticationThrottle\clearLoginThrottle(), ResetAuthenticationThrottle\clearSignupThrottle(), MediaWiki\Auth\AuthManager\continueAccountCreation(), FileCacheBase\getMissesRecent(), FileCacheBase\incrMissesRecent(), BotPassword\login(), JobQueueGroup\push(), JobQueueGroup\queuesHaveJobs(), MediaWiki\ResourceLoader\ResourceLoader\saveModuleDependenciesInternal(), WikiPage\triggerOpportunisticLinksUpdate(), and wfGenerateThumbnail().

◆ getLocalServerInstance()

static ObjectCache::getLocalServerInstance ( $fallback = CACHE_NONE )

static

Factory function for CACHE_ACCEL (referenced from configuration)

This will look for any APC or APCu style server-local cache. A fallback cache can be specified if none is found.

// Direct calls
ObjectCache::getLocalServerInstance( $fallbackType );

// From $wgObjectCaches via newFromParams()
ObjectCache::getLocalServerInstance( [ 'fallback' => $fallbackType ] );

Parameters

int | string | array $fallback Fallback cache or parameter map with 'fallback'

Returns: BagOStuff

Exceptions

InvalidArgumentException

Since: 1.27

Definition at line 298 of file ObjectCache.php.

References $fallback, CACHE_NONE, and getInstance().

Referenced by MediaWiki\Html\TemplateParser\__construct(), and MediaWiki\ResourceLoader\FileModule\compileLessString().

◆ isDatabaseId()

static ObjectCache::isDatabaseId ( $id )

static

Determine whether a config ID would access the database.

Parameters

string | int $id A key in $wgObjectCaches

Returns: bool

Definition at line 326 of file ObjectCache.php.

References $wgObjectCaches.

◆ makeLocalServerCache()

static ObjectCache::makeLocalServerCache ( )

static

Create a new BagOStuff instance for local-server caching.

Only use this if you explicitly require the creation of a fresh instance. Whenever possible, use or inject the object from MediaWikiServices::getLocalServerObjectCache() instead.

NOTE: This method is called very early via Setup.php by ExtensionRegistry, and thus must remain fairly standalone so as to not cause initialization of the MediaWikiServices singleton.

Since: 1.35

Returns: BagOStuff

Definition at line 367 of file ObjectCache.php.

◆ newAnything()

static ObjectCache::newAnything ( $params )

static

Factory function for CACHE_ANYTHING (referenced by configuration)

CACHE_ANYTHING means that stuff has to be cached, not caching is not an option. If a caching method is configured for any of the main caches ($wgMainCacheType, $wgMessageCacheType, $wgParserCacheType), then CACHE_ANYTHING will effectively be an alias to the configured cache choice for that. If no cache choice is configured (by default $wgMainCacheType is CACHE_NONE), then CACHE_ANYTHING will forward to CACHE_DB.

Parameters

array $params

Returns: BagOStuff

Definition at line 242 of file ObjectCache.php.

References getInstance().

◆ newFromParams()

static ObjectCache::newFromParams	(	array	$params,
		MediaWikiServices	$services = `null`
	)

static

Create a new cache object from parameters.

Parameters

array	$params	Must have 'factory' or 'class' property. factory: Callback passed $params that returns BagOStuff. class: BagOStuff subclass constructed with $params. loggroup: Alias to set 'logger' key with LoggerFactory group. .. Other parameters passed to factory or class.
MediaWikiServices \| null	$services	[internal]

Returns: BagOStuff

Definition at line 146 of file ObjectCache.php.

Member Data Documentation

◆ $instances

BagOStuff [] ObjectCache::$instances = []

static

Map of (id => BagOStuff)

Definition at line 68 of file ObjectCache.php.

◆ $localServerCacheClass

string ObjectCache::$localServerCacheClass

static

Access: internal: for ObjectCacheTest

Definition at line 74 of file ObjectCache.php.

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

includes/objectcache/ObjectCache.php

Static Public Member Functions

Static Public Attributes

Detailed Description

Member Function Documentation

◆ clear()

◆ getInstance()

◆ getLocalClusterInstance()

◆ getLocalServerInstance()

◆ isDatabaseId()

◆ makeLocalServerCache()

◆ newAnything()

◆ newFromParams()

Member Data Documentation

◆ $instances

◆ $localServerCacheClass