/*
 * Copyright (C) 2003-2009 JNode.org
 *               2009,2010 Matthias Treydte <mt@waldheinz.de>
 *
 * 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 2.1 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, write to the Free Software Foundation, Inc.,
 * 51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
 */

package org.dbgl.waldheinz.fs.fat;

import java.io.IOException;
import java.nio.ByteBuffer;


/**
 * This is the abstraction used for a device that can hold a {@link FileSystem}.
 * 
 * @author Ewout Prangsma &lt;epr at jnode.org&gt;
 * @author Matthias Treydte &lt;waldheinz at gmail.com&gt;
 */
public interface BlockDevice {

	/**
	 * Gets the total length of this device in bytes.
	 * 
	 * @return the total number of bytes on this device
	 * @throws IOException on error getting the size of this device
	 */
	public abstract long getSize() throws IOException;

	/**
	 * Read a block of data from this device.
	 * 
	 * @param devOffset the byte offset where to read the data from
	 * @param dest the destination buffer where to store the data read
	 * @throws IOException on read error
	 */
	public abstract void read(long devOffset, ByteBuffer dest) throws IOException;

	/**
	 * Returns the size of a sector on this device.
	 * 
	 * @return the sector size in bytes
	 * @throws IOException on error determining the sector size
	 */
	public int getSectorSize() throws IOException;

	/**
	 * Closes this {@code BlockDevice}. No methods of this device may be accesses after this method was called.
	 * 
	 * @throws IOException on error closing this device
	 * @see #isClosed()
	 */
	public void close() throws IOException;

	/**
	 * Checks if this device was already closed. No methods may be called on a closed device (except this method).
	 * 
	 * @return if this device is closed
	 */
	public boolean isClosed();
}
