/*
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.*;
import java.util.logging.*;
/**
* A generic block device backed by a <code>SeekableIODevice</code> instance.
* @author Chris Dennis
*/
public abstract class RawBlockDevice implements BlockDevice
{
private static final Logger LOGGING = Logger.getLogger(RawBlockDevice.class.getName());
private SeekableIODevice data;
private long totalSectors;
/**
* Constructs an instance backed by the given <code>SeekableIODevice</code>.
* @param data device backing
*/
protected RawBlockDevice(SeekableIODevice data)
{
setData(data);
}
public int read(long sectorNumber, byte[] buffer, int size)
{
Integer t;
try {
data.seek(sectorNumber * SECTOR_SIZE);
int pos = 0;
int toRead = Math.min(buffer.length, SECTOR_SIZE * size);
while (true) {
if (pos >= toRead)
return pos;
int read = data.read(buffer, pos, toRead - pos);
if (read < 0)
return pos;
pos += read;
}
} catch (IOException e) {
LOGGING.log(Level.WARNING, "error reading sector " + sectorNumber + ", size = " +size, e);
return -1;
}
}
public int write(long sectorNumber, byte[] buffer, int size)
{
try {
data.seek(sectorNumber * SECTOR_SIZE);
data.write(buffer, 0, size * SECTOR_SIZE);
} catch (IOException e) {
LOGGING.log(Level.WARNING, "error waiting", e);
return -1;
}
return 0;
}
public long getTotalSectors()
{
return totalSectors;
}
public boolean isInserted()
{
return (data != null);
}
public boolean isReadOnly()
{
return data.readOnly();
}
public void close()
{
try {
if (data != null)
data.close();
} catch (IOException e) {
LOGGING.log(Level.INFO, "Couldn't close device", e);
}
}
public void configure(String specs) throws IOException
{
data.configure(specs);
}
/**
* Changes the backing for this device.
* @param data new backing device
*/
protected final void setData(SeekableIODevice data)
{
this.data = data;
if (data == null)
totalSectors = 0;
else
totalSectors = data.length() / SECTOR_SIZE;
}
public String toString()
{
if (data == null)
return "<empty>";
else
return data.toString();
}
}