Add ICacheDriver->getAllKeys method

src/Core/Cache/DatabaseCacheDriver.php

@@ -13,6 +13,16 @@ use Friendica\Util\DateTimeFormat;
  */
 class DatabaseCacheDriver extends AbstractCacheDriver implements ICacheDriver
 {
+	/**
+	 * (@inheritdoc)
+	 */
+	public function getAllKeys()
+	{
+		$stmt = DBA::select('cache', ['k'], ['`expires` >= ?', DateTimeFormat::utcNow()]);
+
+		return DBA::toArray($stmt);
+	}
+
 	/**
 	 * (@inheritdoc)
 	 */