Restarter.java

package thaw.plugins;

import java.awt.GridLayout;
import java.util.Iterator;
import java.util.Observable;
import java.util.Observer;
import java.util.Random;
import java.util.Vector;

import javax.swing.JCheckBox;
import javax.swing.JLabel;
import javax.swing.JPanel;
import javax.swing.JTextField;

import thaw.core.Core;
import thaw.core.I18n;
import thaw.core.Logger;
import thaw.core.Plugin;
import thaw.core.ThawThread;
import thaw.core.ThawRunnable;
import thaw.fcp.FCPTransferQuery;

/**
 * This plugin, after a given time, restart all/some the failed downloads (if maxDownloads >= 0, downloads to restart are choosen randomly).
 * A not too bad example to show how to make plugins.
 * @deprecated When this plugin was created, MaxRetries was stupidly set to 0 instead of -1 => now this plugin is useless.
 */
public class Restarter implements Observer, ThawRunnable, Plugin {

	private int interval = 180; /* in s */
	private boolean restartFatals = false;

	private int timeElapsed = 0;

	private Core core;
	private boolean running = true;

	private Thread restarter = null;

	private JPanel configPanel;

	private JLabel restartIntervalLabel;
	private JTextField restartIntervalField;

	private JCheckBox restartFatalsBox;


	public boolean run(final Core core) {
		this.core = core;

		core.getConfig().addListener("restartInterval", this);
		core.getConfig().addListener("restartFatals",   this);

		/* Reloading value from the configuration */
		try {
			if((core.getConfig().getValue("restartInterval") != null)
			   && (core.getConfig().getValue("restartFatals") != null)) {
				interval = Integer.parseInt(core.getConfig().getValue("restartInterval"));
				restartFatals = Boolean.valueOf(core.getConfig().getValue("restartFatals")).booleanValue();
			}
		} catch(final Exception e) { /* probably conversion errors */ /* Yes I know, it's dirty */
			Logger.notice(this, "Unable to read / understand value from the config. Using default values");
		}


		/* Adding restart config tab to the config window */
		configPanel = new JPanel();
		configPanel.setLayout(new GridLayout(15, 1));

		restartIntervalLabel = new JLabel(I18n.getMessage("thaw.plugin.restarter.interval"));
		restartIntervalField = new JTextField(Integer.toString(interval));

		restartFatalsBox = new JCheckBox(I18n.getMessage("thaw.plugin.restarter.restartFatals"), restartFatals);

		configPanel.add(restartIntervalLabel);
		configPanel.add(restartIntervalField);
		configPanel.add(restartFatalsBox);

		core.getConfigWindow().addTab(I18n.getMessage("thaw.plugin.restarter.configTabName"),
					      thaw.gui.IconBox.minRefreshAction,
					      configPanel);
		core.getConfigWindow().addObserver(this);

		running = true;
		restarter = new ThawThread(this, "Restarter", this);
		restarter.start();

		return true;
	}


	public void stop() {
		core.getConfigWindow().removeTab(configPanel);
		core.getConfigWindow().deleteObserver(this);
		running = false;
	}


	public void run() {
		while(running) {
			try {

				for(timeElapsed = 0 ; (timeElapsed < interval) && running; timeElapsed++) {
					Thread.sleep(1000);
				}

			} catch(final java.lang.InterruptedException e) {
				// We really really really don't care.
			}

			Logger.info(this, "Restarting some failed downloads (if there are some)");

			if(!running)
				break;

			final int maxDownloads = core.getQueueManager().getMaxDownloads();
			int alreadyRunning = 0;
			int failed = 0;
			final Vector runningQueue = core.getQueueManager().getRunningQueue();

			try {
				synchronized(runningQueue) {

					if(maxDownloads >= 0) {
						/* We count how many are really running
						   and we write down those which are failed */
						for(final Iterator it = runningQueue.iterator();
						    it.hasNext();) {
							final FCPTransferQuery query = (FCPTransferQuery)it.next();

							if(query.getQueryType() != 1)
								continue;

							if(query.isRunning() && !query.isFinished()) {
								alreadyRunning++;
							}

							if(query.isFinished() && !query.isSuccessful()
							   && (restartFatals || !query.isFatallyFailed()) ) {
								failed++;
							}
						}

						/* We choose randomly the ones to restart */
						while((alreadyRunning < maxDownloads) && (failed > 0)) {
							final int toRestart = (new Random()).nextInt(failed);

							final Iterator it = runningQueue.iterator();
							int i = 0;

							while(it.hasNext()) {
								final FCPTransferQuery query = (FCPTransferQuery)it.next();

								if(query.getQueryType() != 1)
									continue;

								if(query.isFinished() && !query.isSuccessful()
								   && (restartFatals || !query.isFatallyFailed())) {
									if(i == toRestart) {
										restartQuery(query);
										break;
									}

									i++;
								}
							}

							alreadyRunning++;
							failed--;
						}


					} else { /* => if maxDownloads < 0 */

						/* We restart them all */
						for(final Iterator it = runningQueue.iterator();
						    it.hasNext();) {
							final FCPTransferQuery query = (FCPTransferQuery)it.next();
							if((query.getQueryType() == 1) && query.isFinished()
							   && !query.isSuccessful()
							   && (restartFatals || !query.isFatallyFailed()))
								restartQuery(query);
						}
					}

				}
			} catch(final Exception e) {
				Logger.error(this, "Exception : "+e);
			}

		}
	}


	public void restartQuery(final FCPTransferQuery query) {
		query.stop(core.getQueueManager());

		if(query.getMaxAttempt() >= 0)
			query.setAttempt(0);

		query.start(core.getQueueManager());
	}

	public void update(final Observable o, final Object arg) {
		if(o == core.getConfigWindow()) {

			if(arg == core.getConfigWindow().getOkButton()){
				core.getConfig().setValue("restartInterval", restartIntervalField.getText());
				core.getConfig().setValue("restartFatals",
							  Boolean.toString(restartFatalsBox.isSelected()));

				/* Plugin will be stop() and start(), so no need to reload config */

				return;
			}

			if(arg == core.getConfigWindow().getCancelButton()) {
				restartIntervalField.setText(Integer.toString(interval));
				restartFatalsBox.setSelected(restartFatals);

				return;
			}
		}
	}

	public String getNameForUser() {
		return I18n.getMessage("thaw.plugin.restarter.restarter");
	}

	public javax.swing.ImageIcon getIcon() {
		return thaw.gui.IconBox.refreshAction;
	}
}