[thin_repair] repair now checks the data reference counts.

error_set.h

@@ -0,0 +1,49 @@
+#ifndef ERROR_SET_H
+#define ERROR_SET_H
+
+#include <boost/shared_ptr.hpp>
+#include <list>
+#include <iosfwd>
+
+//----------------------------------------------------------------
+
+namespace persistent_data {
+	// When checking the metadata for a thin device we don't want to
+	// stop at the first error.  Instead should collect as much
+	// information as possible.  The errors are hierarchical, so the
+	// user can control how much detail is displayed.
+	class error_set {
+	public:
+		typedef boost::shared_ptr<error_set> ptr;
+
+		error_set(std::string const &err);
+
+		std::string const &get_description() const;
+		std::list<error_set::ptr> const &get_children() const;
+		void add_child(error_set::ptr err);
+		void add_child(std::string const &err);
+
+	private:
+		std::string err_;
+		std::list<error_set::ptr> children_;
+	};
+
+	// The error_selector is a little proxy class used when printing
+	// errors to a stream.
+	class error_selector {
+	public:
+		error_selector(error_set::ptr errs, unsigned depth);
+
+		void print(std::ostream &out) const;
+
+	private:
+		error_set::ptr errs_;
+		unsigned depth_;
+	};
+
+	std::ostream &operator << (std::ostream &out, error_selector const &errs);
+}
+
+//----------------------------------------------------------------
+
+#endif