org.jscsi.initiator.devices.WhiskasDevice Maven / Gradle / Ivy

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/**
 * 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  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.devices;

import org.apache.log4j.Level;
import org.apache.log4j.Logger;
import org.apache.log4j.net.SocketHubAppender;
import org.apache.log4j.spi.LoggingEvent;

/**
 * JSCSIDevice
 * 
 * Implements a Device that generates the log events to visualize reads and
 * writes with the Wiskas Eclipse Plugin.
 * 
 * 
 * @author Bastian Lemke
 */
public class WhiskasDevice implements Device {

    private final Device device;

    private int blockSize = -1;

    private long blockCount = -1;

    private SocketHubAppender sha;

    private Logger logger;

    /**
     * Constructor to create an WhiskasDevice. The Device has to be initialized
     * before it can be used.
     * 
     * @param initDevice
     *            device to use
     * @throws Exception
     *             if any error occurs
     */
    public WhiskasDevice(final Device initDevice) throws Exception {

        device = initDevice;
    }

    /** {@inheritDoc} */
    public void close() throws Exception {

        if (blockCount == -1) {
            throw new NullPointerException();
        }

        /* Generate teardown message for Whiskas */
        String logMessage = "teardown " + device.getName();
        LoggingEvent logEvent = new LoggingEvent(Logger.class.getName(),
                logger, Level.ALL, logMessage, null);
        sha.append(logEvent);

        blockSize = -1;
        blockCount = -1;

        sha.close();
    }

    /** {@inheritDoc} */
    public int getBlockSize() {

        if (blockSize == -1) {
            throw new IllegalStateException(
                    "You first have to open the Device!");
        }

        return blockSize;
    }

    /** {@inheritDoc} */
    public String getName() {

        return "WhiskasDevice(" + device.getName() + ")";
    }

    /** {@inheritDoc} */
    public long getBlockCount() {

        if (blockCount == -1) {
            throw new IllegalStateException(
                    "You first have to open the Device!");
        }

        return blockCount;
    }

    /** {@inheritDoc} */
    public void open() throws Exception {

        if (blockCount != -1) {
            throw new IllegalStateException("WhiskasDevice is already opened!");
        }

        device.open();

        sha = LogAppender.getInstance();
        logger = Logger.getLogger(WhiskasDevice.class);

        blockSize = device.getBlockSize();
        blockCount = device.getBlockCount();
    }

    /** {@inheritDoc} */
    public void read(final long address, final byte[] data) throws Exception {

        if (blockCount == -1) {
            throw new IllegalStateException(
                    "You first have to open the Device!");
        }

        /* Generate log message for Whiskas */
        String logMessage = device.getName() + ",r," + address + ","
                + data.length / device.getBlockSize();
        LoggingEvent logEvent = new LoggingEvent(Logger.class.getName(),
                logger, Level.ALL, logMessage, null);
        sha.append(logEvent);

        device.read(address, data);
    }

    /** {@inheritDoc} */
    public void write(final long address, final byte[] data) throws Exception {

        if (blockCount == -1) {
            throw new IllegalStateException(
                    "You first have to open the Device!");
        }

        /* Generate log message for Whiskas */
        String logMessage = device.getName() + ",w," + address + ","
                + data.length / device.getBlockSize();
        LoggingEvent logEvent = new LoggingEvent(Logger.class.getName(),
                logger, Level.ALL, logMessage, null);
        sha.append(logEvent);

        device.write(address, data);
    }
}

/**
 * Singleton to prevent the SocketHupAppender from beeing opened more than once.
 * 
 * @author Bastian Lemke
 */
final class LogAppender {

    private static SocketHubAppender sha = null;

    private static final int SOCKET_PORT = 1986;

    private LogAppender() {

    }

    /**
     * Get an instance of the SocketHupAppender.
     * 
     * @return sha
     */
    public static synchronized SocketHubAppender getInstance() {

        if (sha == null) {
            sha = new SocketHubAppender(SOCKET_PORT);
        }
        return sha;
    }
}