/**
* Copyright (c) 2012, University of Konstanz, Distributed Systems Group
* All rights reserved.
*
* Redistribution and use in source and binary forms, with or without
* modification, are permitted provided that the following conditions are met:
* * Redistributions of source code must retain the above copyright
* notice, this list of conditions and the following disclaimer.
* * Redistributions in binary form must reproduce the above copyright
* notice, this list of conditions and the following disclaimer in the
* documentation and/or other materials provided with the distribution.
* * Neither the name of the University of Konstanz nor the
* names of its contributors may be used to endorse or promote products
* derived from this software without specific prior written permission.
*
* THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS "AS IS" AND
* ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT LIMITED TO, THE IMPLIED
* WARRANTIES OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE ARE
* DISCLAIMED. IN NO EVENT SHALL <COPYRIGHT HOLDER> BE LIABLE FOR ANY
* DIRECT, INDIRECT, INCIDENTAL, SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES
* (INCLUDING, BUT NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
* LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND
* ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
* (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE OF THIS
* SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
*/
package org.jscsi.initiator.connection;
import java.nio.ByteBuffer;
import java.util.concurrent.Callable;
import org.jscsi.initiator.connection.phase.IPhase;
/**
* <h1>ITask</h1>
* <p/>
* This interface defines all methods, which a task has to support.
*
* @author Sebastian Graf, University of Konstanz
*/
public interface ITask {
/**
* This method is call, when this <code>ITask</code> instance is polled from
* the head of the <code>taskQueue</code> to start a task.
*
* @return Void nothing at all
* @throws Exception
* if any error occurs.
*/
public Void call() throws Exception;
}
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
/**
* <h1>AbstractTask</h1>
* <p/>
* This abstract class defines all common methods, for the implementing Tasks.
*
* @author Volker Wildi
*/
abstract class AbstractTask implements ITask {
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
/** The <code>Session</code> instance of this task. */
protected final Session session;
/** The <code>IPhase</code> instance of this task. */
protected IPhase phase;
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
/**
* Constructor to create a new, empty <code>AbstractTask</code> subclass
* instance, which is initialized with the given values.
*
* @param initCaller
* The invoking caller of this task.
* @param referenceSession
* The session, where this task is executed in.
*/
AbstractTask(final Session referenceSession) {
session = referenceSession;
phase = referenceSession.phase;
}
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
/** {@inheritDoc} */
@Override
public final String toString() {
return getClass().getSimpleName();
}
}
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
/**
* <h1>LoginTask</h1>
* <p/>
* This defines a LoginTask.
*
* @author Volker Wildi
*/
final class LoginTask extends AbstractTask {
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
/**
* Constructor to create a new, empty <code>LoginTask</code> instance, which
* is initialized with the given values.
*
*
* @param referenceSession
* The session, where this task is executed in.
*/
LoginTask(final Session referenceSession) {
super(referenceSession);
}
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
/** {@inheritDoc} */
public final Void call() throws Exception {
if (phase.login(session)) {
session.finishedTask(this);
}
return null;
}
}
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
/**
* <h1>LogoutTask</h1>
* <p/>
* This defines a LogoutTask.
*
* @author Volker Wildi
*/
final class LogoutTask extends AbstractTask {
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
/**
* Constructor to create a new, empty <code>LogoutTask</code> instance,
* which is initialized with the given values.
*
*
* @param referenceSession
* The session, where this task is executed in.
*/
LogoutTask(final Session referenceSession) {
super(referenceSession);
}
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
/** {@inheritDoc} */
public final Void call() throws Exception {
if (phase.logoutSession(this, session)) {
session.finishedTask(this);
}
return null;
}
}
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
/**
* <h1>IOTask</h1>
* <p/>
* This defines a IOTask.
*
* @author Sebastian Graf, University of Konstanz
*/
abstract class IOTask extends AbstractTask implements Callable<Void> {
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
/** The buffer to store/read the data of this IOTask. */
protected final ByteBuffer buffer;
/** The logical block address of the start of this task. */
protected final int logicalBlockAddress;
/** The length (in bytes) of this task. */
protected final long length;
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
/**
* Constructor to create a new, empty <code>IOTask</code> instance, which is
* initialized with the given values.
*
*
* @param referenceSession
* The session, where this task is executed in.
* @param dst
* Destination ByteBuffer.
* @param initLogicalBlockAddress
* Initial logical Block Address.
* @param initLength
* length of buffer
*/
IOTask(final Session referenceSession, final ByteBuffer dst, final int initLogicalBlockAddress,
final long initLength) {
super(referenceSession);
buffer = dst;
logicalBlockAddress = initLogicalBlockAddress;
length = initLength;
}
}
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
/**
* <h1>ReadTask</h1>
* <p/>
* This defines a ReadTask.
*
* @author Volker Wildi
*/
final class ReadTask extends IOTask {
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
/**
* Constructor to create a new, empty <code>ReadTask</code> instance, which
* is initialized with the given values.
*
* @param referenceSession
* The session, where this task is executed in.
* @param dst
* Destination ByteBuffer.
* @param initLogicalBlockAddress
* Initial logical Block Address.
* @param initLength
* length of buffer
*/
ReadTask(final Session referenceSession, final ByteBuffer dst, final int initLogicalBlockAddress,
final long initLength) {
super(referenceSession, dst, initLogicalBlockAddress, initLength);
}
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
/** {@inheritDoc} */
public final Void call() throws Exception {
try {phase.read(this, session, buffer, logicalBlockAddress, length);} finally {
session.finishedTask(this);
}
return null;
}
}
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
/**
* <h1>WriteTask</h1>
* <p/>
* This defines a WriteTask.
*
* @author Volker Wildi
*/
final class WriteTask extends IOTask {
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
/**
* Constructor to create a new, empty <code>WriteTask</code> instance, which
* is initialized with the given values.
*
*
* @param referenceSession
* The session, where this task is executed in.
* @param src
* Source ByteBuffer.
* @param initLogicalBlockAddress
* Initial logical Block Address.
* @param initLength
* length of buffer
*/
WriteTask(final Session referenceSession, final ByteBuffer src, final int initLogicalBlockAddress,
final long initLength) {
super(referenceSession, src, initLogicalBlockAddress, initLength);
}
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
/** {@inheritDoc} */
public final Void call() throws Exception {
if (phase.write(this, session, buffer, logicalBlockAddress, length)) {
session.finishedTask(this);
}
return null;
}
}
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------
// --------------------------------------------------------------------------