/* XXL: The eXtensible and fleXible Library for data processing

Copyright (C) 2000-2011 Prof. Dr. Bernhard Seeger
                        Head of the Database Research Group
                        Department of Mathematics and Computer Science
                        University of Marburg
                        Germany

This library is free software; you can redistribute it and/or
modify it under the terms of the GNU Lesser General Public
License as published by the Free Software Foundation; either
version 3 of the License, or (at your option) any later version.

This library 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
Lesser General Public License for more details.

You should have received a copy of the GNU Lesser General Public
License along with this library;  If not, see <http://www.gnu.org/licenses/>. 

    http://code.google.com/p/xxl/

*/

package xxl.core.io.raw;

/**
 * Interface for raw file that contains sectors. This interface is implemented 
 * in NativeRawAccess, -RAF, and -RAM.
 * 
 */
public interface RawAccess {

	/**
	 * Opens a device/file.
	 *
	 * @param filename name of file or device
	 * @exception RawAccessException a specialized RuntimeException
	 */
	public void open(String filename) throws RawAccessException;

	/**
	 * Closes a device/file.
	 *
	 * @exception RawAccessException a specialized RuntimeException
	 */
	public void close() throws RawAccessException;

	/**
	 * Writes a sector of a characteristic length to the file/device.
	 *
	 * @param block byte array which will be written to the sector
	 * @param sector number of the sector in the file/device where the block will be written
	 * @exception RawAccessException a specialized RuntimeException
	 */
	public void write(byte[] block, long sector) throws RawAccessException;

	/**
	 * Reads a sector of characteristic Bytes length from the file/device.
	 *
	 * @param block byte array of which will be written to the sector
	 * @param sector number of the sector in the file/device from where the block will be read
	 * @exception RawAccessException a specialized RuntimeException
	 */
	public void read(byte[] block, long sector) throws RawAccessException;

	/**
	 * Returns the amount of sectors in the file/device.
	 *
	 * @return amount of sectors
	 */
	public long getNumSectors();

	/**
	 * Returns the size of a sector of the file/device.
	 *
	 * @return size of sectors
	 */
	public int getSectorSize();
}