thin-provisioning-tools/error_set.h

// Copyright (C) 2011 Red Hat, Inc. All rights reserved.
//
// This file is part of the thin-provisioning-tools source.
//
// thin-provisioning-tools is free software: you can redistribute it
// and/or modify it under the terms of the GNU General Public License
// as published by the Free Software Foundation, either version 3 of
// the License, or (at your option) any later version.
//
// thin-provisioning-tools is distributed in the hope that it will be
// useful, but WITHOUT ANY WARRANTY; without even the implied warranty
// of MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
// GNU General Public License for more details.
//
// You should have received a copy of the GNU General Public License along
// with thin-provisioning-tools.  If not, see
// <http://www.gnu.org/licenses/>.

#ifndef ERROR_SET_H
#define ERROR_SET_H

#include <boost/optional.hpp>
#include <boost/shared_ptr.hpp>
#include <list>
#include <iosfwd>
#include <string>

//----------------------------------------------------------------

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(boost::optional<error_set::ptr> maybe_errs);
		void add_child(std::string const &err);
		bool empty() const;

	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