/*
JPC: An x86 PC Hardware Emulator for a pure Java Virtual Machine
Release Version 2.4
A project from the Physics Dept, The University of Oxford
Copyright (C) 2007-2010 The University of Oxford
This program is free software; you can redistribute it and/or modify
it under the terms of the GNU General Public License version 2 as published by
the Free Software Foundation.
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, write to the Free Software Foundation, Inc.,
51 Franklin Street, Fifth Floor, Boston, MA 02110-1301 USA.
Details (including contact information) can be found at:
jpc.sourceforge.net
or the developer website
sourceforge.net/projects/jpc/
Conceived and Developed by:
Rhys Newman, Ian Preston, Chris Dennis
End of licence header
*/
package org.jpc.support;
import java.io.*;
/**
* IO device used for backing subclasses of {@link RawBlockDevice}.
* @author Chris Dennis
*/
public interface SeekableIODevice
{
/**
* Move read/write offset to given location (in bytes) from the start of the
* device.
* @param offset location to seek to
* @throws java.io.IOException if <code>offset</code> is invalid
*/
public void seek(long offset) throws IOException;
/**
* Writes <code>length</code> bytes from <code>data</code> starting at
* offset into the device.
* @param data buffer to read data from
* @param offset start offset in <code>data<code>
* @param length number of bytes to write
* @return number of bytes written
* @throws java.io.IOException on I/O error.
*/
public int write(byte[] data, int offset, int length) throws IOException;
/**
* Reads <code>length</code> bytes from the device, writing into
* <code>data</code> at <code>offset</code>.
* @param data buffer to write data into
* @param offset start offset in <code>data</code>
* @param length number of bytes to read
* @return number of bytes read
* @throws java.io.IOException on I/O error
*/
public int read(byte[] data, int offset, int length) throws IOException;
/**
* Returns the length of the device.
* @return device length
*/
public long length();
/**
* Returns <code>true</code> if the device cannot be written to.
* @return <code>true</code> if read-only
*/
public boolean readOnly();
/**
* Closes and releases the resources associated with this instance.
*/
public void close() throws IOException;
/**
* Configure device using the given <code>String</code>. What this object
* chooses to do with the given <code>String</code> is implementation
* dependant.
* @param opts configuration string
* @throws java.io.IOException on an I/O error configuring the device
* @throws java.lang.IllegalArgumentException if the configuration string is invalid.
*/
public void configure(String opts) throws IOException, IllegalArgumentException;
}