class ProcessCacheLRU {
/** @var Array */
protected $cache = array(); // (key => prop => value)
+ /** @var Array */
+ protected $cacheTimes = array(); // (key => prop => UNIX timestamp)
protected $maxCacheKeys; // integer; max entries
/**
* Set a property field for a cache entry.
- * This will prune the cache if it gets too large.
+ * This will prune the cache if it gets too large based on LRU.
* If the item is already set, it will be pushed to the top of the cache.
*
* @param $key string
$this->ping( $key ); // push to top
} elseif ( count( $this->cache ) >= $this->maxCacheKeys ) {
reset( $this->cache );
- unset( $this->cache[key( $this->cache )] );
+ $evictKey = key( $this->cache );
+ unset( $this->cache[$evictKey] );
+ unset( $this->cacheTimes[$evictKey] );
}
$this->cache[$key][$prop] = $value;
+ $this->cacheTimes[$key][$prop] = time();
}
/**
*
* @param $key string
* @param $prop string
+ * @param $maxAge integer Ignore items older than this many seconds (since 1.21)
* @return bool
*/
- public function has( $key, $prop ) {
- return isset( $this->cache[$key][$prop] );
+ public function has( $key, $prop, $maxAge = 0 ) {
+ if ( isset( $this->cache[$key][$prop] ) ) {
+ return ( $maxAge <= 0 || ( time() - $this->cacheTimes[$key][$prop] ) <= $maxAge );
+ }
+ return false;
}
/**
public function clear( $keys = null ) {
if ( $keys === null ) {
$this->cache = array();
+ $this->cacheTimes = array();
} else {
foreach ( (array)$keys as $key ) {
unset( $this->cache[$key] );
+ unset( $this->cacheTimes[$key] );
}
}
}
protected $maxFileSize = 4294967296; // integer bytes (4GiB)
+ const CACHE_TTL = 10; // integer; TTL in seconds for process cache entries
+
/**
* @see FileBackend::__construct()
*
wfProfileIn( __METHOD__ );
wfProfileIn( __METHOD__ . '-' . $this->name );
$latest = !empty( $params['latest'] ); // use latest data?
- if ( !$this->cheapCache->has( $path, 'stat' ) ) {
+ if ( !$this->cheapCache->has( $path, 'stat', self::CACHE_TTL ) ) {
$this->primeFileCache( array( $path ) ); // check persistent cache
}
- if ( $this->cheapCache->has( $path, 'stat' ) ) {
+ if ( $this->cheapCache->has( $path, 'stat', self::CACHE_TTL ) ) {
$stat = $this->cheapCache->get( $path, 'stat' );
// If we want the latest data, check that this cached
- // value was in fact fetched with the latest available data.
- if ( !$latest || $stat['latest'] ) {
+ // value was in fact fetched with the latest available data
+ // (the process cache is ignored if it contains a negative).
+ if ( !$latest || ( is_array( $stat ) && $stat['latest'] ) ) {
wfProfileOut( __METHOD__ . '-' . $this->name );
wfProfileOut( __METHOD__ );
return $stat;
$stat = $this->doGetFileStat( $params );
wfProfileOut( __METHOD__ . '-miss-' . $this->name );
wfProfileOut( __METHOD__ . '-miss' );
- if ( is_array( $stat ) ) { // don't cache negatives
+ if ( is_array( $stat ) ) { // file exists
$stat['latest'] = $latest;
$this->cheapCache->set( $path, 'stat', $stat );
$this->setFileCache( $path, $stat ); // update persistent cache
$this->cheapCache->set( $path, 'sha1',
array( 'hash' => $stat['sha1'], 'latest' => $latest ) );
}
- } else {
+ } elseif ( $stat === false ) { // file does not exist
+ $this->cheapCache->set( $path, 'stat', false );
wfDebug( __METHOD__ . ": File $path does not exist.\n" );
+ } else { // an error occurred
+ wfDebug( __METHOD__ . ": Could not stat file $path.\n" );
}
wfProfileOut( __METHOD__ . '-' . $this->name );
wfProfileOut( __METHOD__ );
wfProfileIn( __METHOD__ );
wfProfileIn( __METHOD__ . '-' . $this->name );
$latest = !empty( $params['latest'] ); // use latest data?
- if ( $this->cheapCache->has( $path, 'sha1' ) ) {
+ if ( $this->cheapCache->has( $path, 'sha1', self::CACHE_TTL ) ) {
$stat = $this->cheapCache->get( $path, 'sha1' );
// If we want the latest data, check that this cached
// value was in fact fetched with the latest available data.