some work on cache_restore

caching/mapping_array.h

@@ -0,0 +1,32 @@
+#ifndef CACHE_MAPPING_ARRAY_H
+#define CACHE_MAPPING_ARRAY_H
+
+#include "persistent-data/data-structures/array.h"
+
+//----------------------------------------------------------------
+
+namespace caching {
+	namespace mapping_array_detail {
+		struct mapping {
+			uint64_t oblock_;
+			uint32_t flags_;
+		};
+
+		struct mapping_traits {
+			typedef base::le64 disk_type;
+			typedef mapping value_type;
+			typedef no_op_ref_counter<value_type> ref_counter;
+
+			static void unpack(disk_type const &disk, value_type &value);
+			static void pack(value_type const &value, disk_type &disk);
+		};
+
+		// FIXME: damage visitor stuff
+	}
+
+	typedef persistent_data::array<mapping_array_detail::mapping_traits> mapping_array;
+}
+
+//----------------------------------------------------------------
+
+#endif