/*
   Copyright (C) 2001-2006, William Joseph.
   All Rights Reserved.

   This file is part of GtkRadiant.

   GtkRadiant 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 2 of the License, or
   (at your option) any later version.

   GtkRadiant 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 GtkRadiant; if not, write to the Free Software
   Foundation, Inc., 51 Franklin St, Fifth Floor, Boston, MA  02110-1301  USA
 */

#if !defined( INCLUDED_IDATASTREAM_H )
#define INCLUDED_IDATASTREAM_H

#include <cstddef>

class StreamBase
{
public:
typedef std::size_t size_type;
typedef unsigned char byte_type;
};

/// \brief A read-only byte-stream.
class InputStream : public StreamBase
{
public:
/// \brief Attempts to read the next \p length bytes from the stream to \p buffer.
/// Returns the number of bytes actually stored in \p buffer.
virtual size_type read( byte_type* buffer, size_type length ) = 0;
};

/// \brief A write-only byte-stream.
class OutputStream : public StreamBase
{
public:
/// \brief Attempts to write \p length bytes to the stream from \p buffer.
/// Returns the number of bytes actually read from \p buffer.
virtual size_type write( const byte_type* buffer, size_type length ) = 0;
};

class SeekableStream
{
public:
typedef int offset_type;
typedef std::size_t position_type;

enum seekdir
{
	beg,
	cur,
	end,
};

/// \brief Sets the current \p position of the stream relative to the start.
virtual position_type seek( position_type position ) = 0;
/// \brief Sets the current \p position of the stream relative to either the start, end or current position.
virtual position_type seek( offset_type offset, seekdir direction ) = 0;
/// \brief Returns the current position of the stream.
virtual position_type tell() const = 0;
};

/// \brief A seekable read-only byte-stream.
class SeekableInputStream : public InputStream, public SeekableStream
{
};

/// \brief A seekable write-only byte-stream.
class SeekableOutputStream : public OutputStream, public SeekableStream
{
};

#endif
