WANObjectCacheReaper Class Reference

Class for scanning through chronological, log-structured data or change logs and locally purging cache keys related to entities that appear in this data. More...

Inheritance diagram for WANObjectCacheReaper:

Collaboration diagram for WANObjectCacheReaper:

Public Member Functions
	__construct (WANObjectCache $cache, BagOStuff $store, callable $logCallback, callable $keyCallback, array $params)
	getState ()
	invoke ( $n=100)
	Check and reap stale keys based on a chunk of events.
	setLogger (LoggerInterface $logger)

Protected Attributes
WANObjectCache	$cache
string	$channel
int	$initialStartWindow
callable	$keyListCallback
callable	$logChunkCallback
LoggerInterface	$logger
BagOStuff	$store

Detailed Description

Class for scanning through chronological, log-structured data or change logs and locally purging cache keys related to entities that appear in this data.

This is useful for repairing cache when purges are missed by using a reliable stream, such as Kafka or a replicated MySQL table. Purge loss between datacenters is expected to be more common than within them.

Since

1.28

Definition at line 37 of file WANObjectCacheReaper.php.

Constructor & Destructor Documentation

__construct()

WANObjectCacheReaper::__construct	(	WANObjectCache	$cache,
		BagOStuff	$store,
		callable	$logCallback,
		callable	$keyCallback,
		array	$params )

Parameters

WANObjectCache	$cache	Cache to reap bad keys from
BagOStuff	$store	Cache to store positions use for locking
callable	$logCallback	Callback taking arguments: The starting position as a UNIX timestamp The starting unique ID used for breaking timestamp collisions or null The ending position as a UNIX timestamp The maximum number of results to return It returns a list of maps of (key: cache key, pos: UNIX timestamp, id: unique ID) for each key affected, with the corrosponding event timestamp/ID information. The events should be in ascending order, by (timestamp,id).
callable	$keyCallback	Callback taking arguments: The WANObjectCache instance An object from the event log It should return a list of WAN cache keys. The callback must fully duck-type test the object, since can be any model class.
array	$params	Additional options: channel: the name of the update event stream. Default: WANObjectCache::DEFAULT_PURGE_CHANNEL. initialStartWindow: seconds back in time to start if the position is lost. Default: 1 hour. logger: an SPL monolog instance [optional]

Definition at line 77 of file WANObjectCacheReaper.php.

References $cache, $params, $store, and cache.

Member Function Documentation

getState()

WANObjectCacheReaper::getState

(

)

Returns

array|bool Returns (pos, id) map or false if not set

Definition at line 199 of file WANObjectCacheReaper.php.

invoke()

WANObjectCacheReaper::invoke ( $n = 100 )

final

Check and reap stale keys based on a chunk of events.

Parameters

int

$n

Number of events

Returns

int Number of keys checked

Definition at line 113 of file WANObjectCacheReaper.php.

References $initialStartWindow, $keys, and cache.

setLogger()

WANObjectCacheReaper::setLogger

(

LoggerInterface

$logger

)

Definition at line 103 of file WANObjectCacheReaper.php.

References $logger.

Member Data Documentation

$cache

WANObjectCache WANObjectCacheReaper::$cache

protected

Definition at line 39 of file WANObjectCacheReaper.php.

Referenced by __construct().

$channel

string WANObjectCacheReaper::$channel

protected

Definition at line 50 of file WANObjectCacheReaper.php.

$initialStartWindow

int WANObjectCacheReaper::$initialStartWindow

protected

Definition at line 52 of file WANObjectCacheReaper.php.

Referenced by invoke().

$keyListCallback

callable WANObjectCacheReaper::$keyListCallback

protected

Definition at line 45 of file WANObjectCacheReaper.php.

$logChunkCallback

callable WANObjectCacheReaper::$logChunkCallback

protected

Definition at line 43 of file WANObjectCacheReaper.php.

$logger

LoggerInterface WANObjectCacheReaper::$logger

protected

Definition at line 47 of file WANObjectCacheReaper.php.

Referenced by setLogger().

$store

BagOStuff WANObjectCacheReaper::$store

protected

Definition at line 41 of file WANObjectCacheReaper.php.

Referenced by __construct().

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

• includes/libs/objectcache/WANObjectCacheReaper.php