$this->maxCacheKeys = $maxKeys;
}
+ /**
+ * @param array $values Key/value map in order of increasingly recent access
+ * @param int $maxKeys
+ * @return MapCacheLRU
+ * @since 1.30
+ */
+ public static function newFromArray( array $values, $maxKeys ) {
+ $mapCache = new self( $maxKeys );
+ $mapCache->cache = ( count( $values ) > $maxKeys )
+ ? array_slice( $values, -$maxKeys, null, true )
+ : $values;
+
+ return $mapCache;
+ }
+
+ /**
+ * @return array Key/value map in order of increasingly recent access
+ * @since 1.30
+ */
+ public function toArray() {
+ return $this->cache;
+ }
+
/**
* Set a key/value pair.
* 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.
*
+ * To reduce evictions due to one-off use of many new keys, $rank can be
+ * set to have keys start at the top of a bottom fraction of the list. A value
+ * of 3/8 means values start at the top of the bottom 3/8s of the list and are
+ * moved to the top of the list when accessed a second time.
+ *
* @param string $key
* @param mixed $value
+ * @param float $rank Bottom fraction of the list where keys start off [Default: 1.0]
* @return void
*/
- public function set( $key, $value ) {
+ public function set( $key, $value, $rank = 1.0 ) {
if ( $this->has( $key ) ) {
$this->ping( $key );
} elseif ( count( $this->cache ) >= $this->maxCacheKeys ) {
$evictKey = key( $this->cache );
unset( $this->cache[$evictKey] );
}
- $this->cache[$key] = $value;
+
+ if ( $rank < 1.0 && $rank > 0 ) {
+ $offset = intval( $rank * count( $this->cache ) );
+ $this->cache = array_slice( $this->cache, 0, $offset, true )
+ + [ $key => $value ]
+ + array_slice( $this->cache, $offset, null, true );
+ } else {
+ $this->cache[$key] = $value;
+ }
}
/**
*/
public function has( $key ) {
if ( !is_int( $key ) && !is_string( $key ) ) {
- throw new MWException( __METHOD__ . ' called with invalid key. Must be string or integer.' );
+ throw new UnexpectedValueException(
+ __METHOD__ . ' called with invalid key. Must be string or integer.' );
}
return array_key_exists( $key, $this->cache );
}
* @since 1.28
* @param string $key
* @param callable $callback Callback that will produce the value
+ * @param float $rank Bottom fraction of the list where keys start off [Default: 1.0]
* @return mixed The cached value if found or the result of $callback otherwise
*/
- public function getWithSetCallback( $key, callable $callback ) {
+ public function getWithSetCallback( $key, callable $callback, $rank = 1.0 ) {
if ( $this->has( $key ) ) {
$value = $this->get( $key );
} else {
$value = call_user_func( $callback );
if ( $value !== false ) {
- $this->set( $key, $value );
+ $this->set( $key, $value, $rank );
}
}