mediawiki-extensions-Echo/includes/cache/LocalCache.php
Timo Tijhof 59e1be5af9 Migrate LocalCache from MapCacheLRU to HashBagOStuff
Depends on If39d72983 for HashBagOStuff::clear().

Change-Id: I90a03ea44430223ef420be9175bea9bcc8da8cf5
2015-11-03 06:49:50 +00:00

100 lines
1.8 KiB
PHP

<?php
/**
* Base Local cache object, which borrows the concept from Flow user listener
*/
abstract class EchoLocalCache {
/**
* Max number of objects to hold in $targets. In theory, 1000
* is very hard to reach in a normal web request. We need to
* put cap so it doesn't reach memory limit when running email
* digest against large amount of notications
*/
const TARGET_MAX_NUM = 1000;
/**
* Target object cache
* @var HashBagOStuff
*/
protected $targets;
/**
* Lookup ids that have not been resolved for a target
* @param int[]
*/
protected $lookups = array();
/**
* Resolve ids in lookups to targets
*/
abstract protected function resolve();
/**
* Use Factory method like EchoTitleLocalCache::create()
*/
protected function __construct() {
$this->targets = new HashBagOStuff( array( 'maxKeys' => self::TARGET_MAX_NUM ) );
}
/**
* Add a key to the lookup and the key is used to resolve cache target
*
* @param int $key
*/
public function add( $key, $target = null ) {
if (
count( $this->lookups ) < self::TARGET_MAX_NUM
&& !$this->targets->get( $key )
) {
$this->lookups[$key] = $key;
}
}
/**
* Get the cache target based on the key
*
* @param int $key
* @return mixed|null
*/
public function get( $key ) {
$target = $this->targets->get( $key );
if ( $target ) {
return $target;
}
if ( isset( $this->lookups[$key] ) ) {
$this->resolve();
$target = $this->targets->get( $key );
if ( $target ) {
return $target;
}
}
return null;
}
/**
* Clear everything in local cache
*/
public function clearAll() {
$this->targets->clear();
$this->lookups = array();
}
/**
* @return int[]
*/
public function getLookups() {
return $this->lookups;
}
/**
* @return BagOStuff
*/
public function getTargets() {
return $this->targets;
}
}