--- /dev/null
+# -*- coding: utf-8 -*-
+# This file is part of Wolnelektury, licensed under GNU Affero GPLv3 or later.
+# Copyright © Fundacja Nowoczesna Polska. See NOTICE for more information.
+#
+from os.path import abspath, join, exists
+from shutil import rmtree
+from waiter.settings import WAITER_ROOT
+
+
+def check_abspath(path):
+ abs_path = abspath(join(WAITER_ROOT, path))
+ if not abs_path.startswith(WAITER_ROOT):
+ raise ValueError('Path not inside WAITER_ROOT.')
+ return abs_path
+
+
+def clear_cache(path):
+ abs_path = check_abspath(path)
+ if exists(abs_path):
+ rmtree(abs_path)