--- /dev/null
+<?php
+
+/**
+ * @file
+ * Definition of Drush\Config\StorageFilter.
+ */
+
+namespace Drush\Config;
+
+use Drupal\Core\Config\StorageInterface;
+
+interface StorageFilter {
+
+ /**
+ * Filters configuration data after it is read from storage.
+ *
+ * @param string $name
+ * The name of a configuration object to load.
+ * @param array $data
+ * The configuration data to filter.
+ *
+ * @return array $data
+ * The filtered data.
+ */
+ public function filterRead($name, $data);
+
+ /**
+ * Filter configuration data before it is written to storage.
+ *
+ * @param string $name
+ * The name of a configuration object to save.
+ * @param array $data
+ * The configuration data to filter.
+ * @param StorageInterface
+ * The storage object that the filtered data will be
+ * written to. Provided in case the filter needs to
+ * read the existing configuration before writing it.
+ *
+ * @return array $data
+ * The filtered data.
+ */
+ public function filterWrite($name, array $data, StorageInterface $storage);
+
+}