org.paxle.core.io.temp.impl.CommandTempReleaser.java Source code

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Here is the source code for org.paxle.core.io.temp.impl.CommandTempReleaser.java

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/**
 * This file is part of the Paxle project.
 * Visit http://www.paxle.net for more information.
 * Copyright 2007-2010 the original author or authors.
 *
 * Licensed under the terms of the Common Public License 1.0 ("CPL 1.0").
 * Any use, reproduction or distribution of this program constitutes the recipient's acceptance of this agreement.
 * The full license text is available under http://www.opensource.org/licenses/cpl1.0.txt
 * or in the file LICENSE.txt in the root directory of the Paxle distribution.
 *
 * Unless required by applicable law or agreed to in writing, this software is distributed
 * on an "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 */

package org.paxle.core.io.temp.impl;

import java.io.File;
import java.io.FileNotFoundException;
import java.util.LinkedList;
import java.util.Map;
import java.util.Queue;

import org.apache.commons.logging.Log;
import org.apache.commons.logging.LogFactory;
import org.apache.felix.scr.annotations.Component;
import org.apache.felix.scr.annotations.Property;
import org.apache.felix.scr.annotations.Reference;
import org.apache.felix.scr.annotations.Service;
import org.osgi.service.event.Event;
import org.osgi.service.event.EventConstants;
import org.osgi.service.event.EventHandler;
import org.paxle.core.doc.CommandEvent;
import org.paxle.core.doc.ICommand;
import org.paxle.core.doc.ICommandTracker;
import org.paxle.core.doc.ICrawlerDocument;
import org.paxle.core.doc.IParserDocument;
import org.paxle.core.io.temp.ITempFileManager;

/**
 * This component releases all the temporary files associated with a command on desctruction of the latter object
 */
@Component(immediate = true, metatype = false)
@Service(EventHandler.class)
@Property(name = EventConstants.EVENT_TOPIC, value = { CommandEvent.TOPIC_DESTROYED })
public class CommandTempReleaser implements EventHandler {

    /**
     * For logging
     */
    private final Log logger = LogFactory.getLog(CommandTempReleaser.class);

    @Reference
    protected ICommandTracker tracker;

    @Reference
    protected ITempFileManager tfm;

    private void releaseCommandFiles(final ICommand cmd, final Long id) {
        try {
            File file;
            final ICrawlerDocument cdoc = cmd.getCrawlerDocument();
            if (cdoc != null && (file = cdoc.getContent()) != null) {
                if (tfm.isKnown(file)) {
                    try {
                        tfm.releaseTempFile(file);
                    } catch (FileNotFoundException e) {
                        this.logger.warn("downloaded crawler-data not available for release");
                    }
                } else {
                    this.logger.debug(String.format("Crawlerdoc tempfile %s not managed by tempfilemanager",
                            file.toString()));
                }
            }

            final Queue<Map.Entry<String, IParserDocument>> pdocs = new LinkedList<Map.Entry<String, IParserDocument>>();

            IParserDocument pdoc = cmd.getParserDocument();
            Map.Entry<String, IParserDocument> entry = null;
            if (pdoc != null) {
                do {
                    if (entry != null) {
                        pdoc = entry.getValue();
                    }

                    if ((file = pdoc.getTextFile()) != null) {
                        if (tfm.isKnown(file)) {
                            try {
                                tfm.releaseTempFile(file);
                            } catch (FileNotFoundException e) {
                                final String msg = (entry == null) ? "parser-document"
                                        : "sub parser-document '" + entry.getKey() + "'";
                                logger.warn(String.format("data of %s of cmd [%06d] not available for release", msg,
                                        id));
                            }
                        } else {
                            this.logger.debug(String.format("Parserdoc tempfile %s not managed by tempfilemanager",
                                    file.toString()));
                        }
                    }

                    pdocs.addAll(pdoc.getSubDocs().entrySet());
                } while ((entry = pdocs.poll()) != null);
            }

        } catch (Throwable e) {
            this.logger.error(String.format("Unexpected '%s' while releasing temporary files of command '%s'.",
                    e.getClass().getName(), cmd.getLocation()), e);
        }
    }

    /**
     * @see EventHandler#handleEvent(Event)
     */
    public void handleEvent(Event event) {
        // getting the ID of the command that was destroyed
        final Long id = (Long) event.getProperty(CommandEvent.PROP_COMMAND_ID);

        // getting a reference command from the command-tracker
        final ICommand cmd = this.tracker.getCommandByID(id);
        if (cmd != null) {
            // releasing temp file(s)
            this.releaseCommandFiles(cmd, id);
        } else {
            this.logger.warn(
                    String.format("Commandtracker did not return a reference to the command with ID '%d'.", id));
        }
    }
}