// ftpd is a server implementation based on the following:
// - RFC  959 (https://tools.ietf.org/html/rfc959)
// - RFC 3659 (https://tools.ietf.org/html/rfc3659)
// - suggested implementation details from https://cr.yp.to/ftp/filesystem.html
//
// Copyright (C) 2020 Michael Theall
//
// This program 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.
//
// This program 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 this program.  If not, see <https://www.gnu.org/licenses/>.

#pragma once

#include <cstddef>
#include <memory>

class IOBuffer
{
public:
	~IOBuffer ();

	IOBuffer (std::size_t size_);

	char *freeArea () const;
	std::size_t freeSize () const;
	void markFree (std::size_t size_);

	char *usedArea () const;
	std::size_t usedSize () const;
	void markUsed (std::size_t size_);

	bool empty () const;
	std::size_t capacity () const;
	void clear ();
	void coalesce ();

private:
	std::unique_ptr<char[]> m_buffer;
	std::size_t const m_size;
	std::size_t m_start = 0;
	std::size_t m_end   = 0;
};