1 files changed, 102 insertions, 0 deletions
diff --git a/www/wiki/extensions/SemanticMediaWiki/src/Utils/Lru.php b/www/wiki/extensions/SemanticMediaWiki/src/Utils/Lru.php
new file mode 100644
index 00000000..2f785bbf
--- /dev/null
+++ b/www/wiki/extensions/SemanticMediaWiki/src/Utils/Lru.php
@@ -0,0 +1,102 @@
+<?php
+
+namespace SMW\Utils;
+
+/**
+ * @license GNU GPL v2+
+ * @since 3.0
+ *
+ * @author mwjames
+ */
+class Lru {
+
+	/**
+	 * @var integer
+	 */
+	private $size;
+
+	/**
+	 * @var array
+	 */
+	private $cache = [];
+
+	/**
+	 * @var array
+	 */
+	private $count = 0;
+
+	/**
+	 * @since 3.0
+	 *
+	 * @param integer size
+	 */
+	public function __construct( $size = 1000 ) {
+		$this->size = $size;
+	}
+
+	/**
+	 * @since 3.0
+	 *
+	 * @param string|integer $key
+	 * @param mixed $value
+	 */
+	public function set( $key, $value ) {
+
+		$this->count++;
+
+		if ( isset( $this->cache[$key] ) ) {
+			$this->count--;
+			$value = $this->cache[$key];
+			unset( $this->cache[$key] );
+		} elseif ( $this->count > $this->size ) {
+			$this->count--;
+			reset( $this->cache );
+			unset( $this->cache[ key( $this->cache ) ] );
+		}
+
+		$this->cache[$key] = $value;
+	}
+
+	/**
+	 * @since 3.0
+	 *
+	 * @param string|integer $key
+	 *
+	 * @return mixed
+	 */
+	public function get( $key, $default = null ) {
+
+		if ( !isset( $this->cache[$key] ) ) {
+			return $default;
+		}
+
+		$value = $this->cache[$key];
+		unset( $this->cache[$key] );
+		$this->cache[$key] = $value;
+
+		return $value;
+	}
+
+	/**
+	 * @since 3.0
+	 *
+	 * @param string|integer $key
+	 */
+	public function delete( $key ) {
+
+		if ( !isset( $this->cache[$key] ) ) {
+			return $default;
+		}
+
+		$this->count--;
+		unset( $this->cache[$key] );
+	}
+
+	/**
+	 * @since 3.0
+	 */
+	public function toArray() {
+		return $this->cache;
+	}
+
+}