[caching/mapping_array] add damage visitor

caching/mapping_array.cc

@@ -26,3 +26,49 @@ mapping_traits::pack(value_type const &value, disk_type &disk)
 }
 
 //----------------------------------------------------------------
+
+missing_mappings::missing_mappings(run<uint32_t> const &keys,
+				   std::string const &desc)
+	: keys_(keys),
+	  desc_(desc)
+{
+
+}
+
+void
+missing_mappings::visit(damage_visitor &v) const
+{
+	v.visit(*this);
+}
+
+namespace {
+	struct no_op_visitor {
+		virtual void visit(uint32_t index,
+				   mapping_traits::value_type const &v) {
+		}
+	};
+
+	class ll_damage_visitor {
+	public:
+		ll_damage_visitor(damage_visitor &v)
+		: v_(v) {
+		}
+
+		virtual void visit(array_detail::damage const &d) {
+			v_.visit(missing_mappings(d.lost_keys_, d.desc_));
+		}
+
+	private:
+		damage_visitor &v_;
+	};
+}
+
+void
+caching::check_mapping_array(mapping_array const &array, damage_visitor &visitor)
+{
+	no_op_visitor vv;
+	ll_damage_visitor ll(visitor);
+	array.visit_values(vv, ll);
+}
+
+//----------------------------------------------------------------