/*************************************************************************
 *  Copyright (C) 2010 by Volker Lanz <vl@fidra.de>                      *
 *                                                                       *
 *  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 <http://www.gnu.org/licenses/>.*
 *************************************************************************/

#if !defined(COPYSOURCESHRED__H)

#define COPYSOURCESHRED__H

#include "core/copysource.h"

#include <QFile>

class CopyTarget;

/** A source for securely overwriting a partition (shredding).

	Represents a source of data (random or zeros) to copy from. Used to securely overwrite data on disk.

	@author Volker Lanz <vl@fidra.de>
*/
class CopySourceShred : public CopySource
{
	public:
		CopySourceShred(qint64 size, qint32 sectorsize);

	public:
		virtual bool open();
		virtual bool readSectors(void* buffer, qint64 readOffset, qint64 numSectors);
		virtual qint64 length() const;

		virtual qint32 sectorSize() const { return m_SectorSize; } /**< @return the file's sector size */
		virtual bool overlaps(const CopyTarget&) const { return false; } /**< @return false for shred source */
		virtual qint64 firstSector() const { return 0; } /**< @return 0 for shred source */
		virtual qint64 lastSector() const { return length(); } /**< @return equal to length for shred source. @see length() */

	protected:
		QFile& sourceFile() { return m_SourceFile; }
		const QFile& sourceFile() const { return m_SourceFile; }
		qint32 size() const { return m_Size; }

	private:
		qint64 m_Size;
		qint32 m_SectorSize;
		QFile m_SourceFile;
};

#endif
