Functions to get cache objects. More...

Collaboration diagram for ObjectCache:

[legend]

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

static	detectLocalServerCache ()
	Detects which local server cache library is present and returns a configuration for it. 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 DefaultSettings.php) More...

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

static	newAnything ( $params)
	Factory function for CACHE_ANYTHING (referenced from DefaultSettings.php) More...

static	newFromParams ( $params)
	Create a new cache object from parameters. More...

static	newWANCacheFromParams (array $params)
	Create a new cache object of the specified type. More...

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

static WANObjectCache[]	$wanInstances = []
	Map of (id => WANObjectCache) More...

Static Private Member Functions
static	getDefaultKeyspace ()
	Get the default keyspace for this wiki. More...

static	newFromId ( $id)
	Create a new cache object of the specified type. More...

static	newWANCacheFromId ( $id)
	Create a new cache object of the specified type. More...

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).

The former should always use strongly consistent stores, so callers don't have to deal with stale reads. The latter may be eventually consistent, but callers can use BagOStuff:READ_LATEST to see the latest available data.

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 cache instances (BagOStuff and WANObjectCache) 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 68 of file ObjectCache.php.

Member Function Documentation

◆ clear()

static ObjectCache::clear ( )

static

Clear all the cached instances.

Definition at line 351 of file ObjectCache.php.

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

◆ detectLocalServerCache()

static ObjectCache::detectLocalServerCache ( )

static

Detects which local server cache library is present and returns a configuration for it.

Since: 1.32

Returns: int|string Index to cache in $wgObjectCaches

Definition at line 362 of file ObjectCache.php.

References CACHE_NONE.

Referenced by ExtensionRegistry\loadFromQueue().

◆ getDefaultKeyspace()

static ObjectCache::getDefaultKeyspace ( )

staticprivate

Get the default keyspace for this wiki.

This is either the value of the CachePrefix configuration variable, or (if the former is unset) the DBname configuration variable, with DBprefix (if defined).

Returns: string

Definition at line 139 of file ObjectCache.php.

References $wgCachePrefix, and WikiMap\getCurrentWikiDbDomain().

Referenced by newFromParams().

◆ getInstance()

static ObjectCache::getInstance ( $id )

static

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

Parameters

string $id A key in $wgObjectCaches.

Returns: BagOStuff

Definition at line 80 of file ObjectCache.php.

References newFromId().

Referenced by MediaWiki\Session\SessionManager\__construct(), Installer\__construct(), WikiPage\doDeleteArticleBatched(), ApiScribuntoConsole\execute(), getLocalClusterInstance(), getLocalServerInstance(), newAnything(), ManageJobs\repushAbandoned(), Article\showMissingArticle(), wfGetCache(), and wfGetMessageCacheStorage().

◆ getLocalClusterInstance()

static ObjectCache::getLocalClusterInstance ( )

static

Get the main cluster-local cache object.

Since: 1.27

Returns: BagOStuff

Definition at line 342 of file ObjectCache.php.

References $wgMainCacheType, and getInstance().

Referenced by MediaWiki\Auth\ThrottlePreAuthenticationProvider\__construct(), MediaWiki\Auth\Throttler\__construct(), PoolWorkArticleView\__construct(), Pingback\acquireLock(), MediaWiki\Auth\AuthManager\autoCreateUser(), ResetAuthenticationThrottle\clearLoginThrottle(), ResetAuthenticationThrottle\clearSignupThrottle(), MediaWiki\Auth\AuthManager\continueAccountCreation(), WANCacheReapUpdate\doUpdate(), SpamBlacklist\filter(), CacheHelper\getCacheKeyString(), ApiCategoryTree\getHTML(), FileCacheBase\getMissesRecent(), SimpleCaptcha\increaseBadLoginCounter(), FileCacheBase\incrMissesRecent(), SimpleCaptcha\isBadLoginPerUserTriggered(), SimpleCaptcha\isBadLoginTriggered(), BotPassword\login(), User\pingLimiter(), JobQueueGroup\push(), JobQueueGroup\queuesHaveJobs(), SimpleCaptcha\resetBadLoginCounter(), ResourceLoaderModule\saveFileDependencies(), WikiPage\triggerOpportunisticLinksUpdate(), wfForeignMemcKey(), wfGenerateThumbnail(), wfGetMainCache(), wfGlobalCacheKey(), and wfMemcKey().

◆ getLocalServerInstance()

static ObjectCache::getLocalServerInstance ( $fallback = CACHE_NONE )

static

Factory function for CACHE_ACCEL (referenced from DefaultSettings.php)

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 268 of file ObjectCache.php.

References $cache, $fallback, CACHE_NONE, and getInstance().

Referenced by FileContentsHasher\__construct(), ResourceLoaderFileModule\compileLessFile(), FileBackendGroup\config(), IcuCollation\getFirstLetterData(), MediaWikiGadgetsDefinitionRepo\loadGadgets(), Scribunto_LuaEngine\loadLibraryFromFile(), and ScribuntoHooks\reportTiming().

◆ getWANInstance()

static ObjectCache::getWANInstance ( $id )

static

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

Since: 1.26

Parameters

string $id A key in $wgWANObjectCaches.

Returns: WANObjectCache

Deprecated:: since 1.34 Use MediaWikiServices::getMainWANObjectCache instead

Definition at line 96 of file ObjectCache.php.

References newWANCacheFromId(), and wfDeprecated().

◆ newAnything()

static ObjectCache::newAnything ( $params )

static

Factory function for CACHE_ANYTHING (referenced from DefaultSettings.php)

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