org.silverpeas.core.io.temp.LastModifiedDateFileTask.java Source code

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Here is the source code for org.silverpeas.core.io.temp.LastModifiedDateFileTask.java

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/*
 * Copyright (C) 2000 - 2018 Silverpeas
 *
 * This program is free software: you can redistribute it and/or modify
 * it under the terms of the GNU Affero General Public License as
 * published by the Free Software Foundation, either version 3 of the
 * License, or (at your option) any later version.
 *
 * As a special exception to the terms and conditions of version 3.0 of
 * the GPL, you may redistribute this Program in connection with Free/Libre
 * Open Source Software ("FLOSS") applications as described in Silverpeas's
 * FLOSS exception.  You should have received a copy of the text describing
 * the FLOSS exception, and it is also available here:
 * "https://www.silverpeas.org/legal/floss_exception.html"
 *
 * 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 Affero General Public License for more details.
 *
 * You should have received a copy of the GNU Affero General Public License
 * along with this program.  If not, see <http://www.gnu.org/licenses/>.
 */
package org.silverpeas.core.io.temp;

import org.apache.commons.io.FileUtils;
import org.apache.commons.io.filefilter.FileFilterUtils;
import org.apache.commons.lang3.tuple.Pair;
import org.silverpeas.core.cache.service.CacheServiceProvider;
import org.silverpeas.core.thread.ManagedThreadPool;
import org.silverpeas.core.util.logging.SilverLogger;

import java.io.File;
import java.util.LinkedHashMap;
import java.util.Map;

/**
 * A task in order to update asynchronously the last modified date of given file and folders.
 */
public class LastModifiedDateFileTask implements Runnable {

    private static final Map<File, Long> requestMap = new LinkedHashMap<>();

    /**
     * All the requests are processed by a single background thread. This thread is built and
     * started by the start method.
     */
    private static boolean running = false;

    /**
     * Builds and starts the thread which will process all the requests. This method is
     * synchronized on the requests queue in order to guarantee that only one
     * LastModifiedDateFileThread is running.
     */
    private static void startIfNotAlreadyDone() {
        if (!isRunning()) {
            running = true;
            ManagedThreadPool.getPool().invoke(new LastModifiedDateFileTask());
        }
    }

    /**
     * Add a file to process.
     * @param file
     */
    public static void addFile(File file) {
        synchronized (requestMap) {
            requestMap.put(file, System.currentTimeMillis());
            startIfNotAlreadyDone();
        }
    }

    /**
     * Indicates if the thread is running.
     * @return true if running, false otherwise.
     */
    public static boolean isRunning() {
        synchronized (requestMap) {
            return running;
        }
    }

    /**
     * The constructor is private : only one MailSenderThread will be created to process all the
     * request.
     */
    private LastModifiedDateFileTask() {
    }

    /**
     * Process all the requests. This method should be private but is already declared public in
     * the
     * base class Thread.
     */
    @Override
    public void run() {
        Pair<File, Long> pair = nextRequest();

        // The loop condition must be verified on a private attribute of run method (not on the static
        // running attribute) in order to avoid concurrent access.
        while (pair != null) {
            CacheServiceProvider.clearAllThreadCaches();

            /*
             * Each request is processed out of the synchronized block so the others threads (which put
             * the requests) will not be blocked.
             */
            try {
                File currentFile = pair.getKey();
                Long lastModifiedDate = pair.getValue();
                if (currentFile.isFile()) {
                    setLastModifiedDate(currentFile, lastModifiedDate);
                } else if (currentFile.isDirectory()) {
                    for (File file : FileUtils.listFilesAndDirs(currentFile, FileFilterUtils.trueFileFilter(),
                            FileFilterUtils.trueFileFilter())) {
                        setLastModifiedDate(file, lastModifiedDate);
                    }
                }
            } catch (Exception e) {
                SilverLogger.getLogger(e);
            }

            // Getting the next request if any.
            pair = nextRequest();
        }
    }

    private void setLastModifiedDate(final File file, final long lastModifiedDate) {
        boolean isOk = file.setLastModified(lastModifiedDate);
        if (!isOk) {
            SilverLogger.getLogger(this).warn("Unable set last modification date to file " + file.getPath());
        }
    }

    /**
     * Gets the next request.
     * @return the next request.
     */
    private Pair<File, Long> nextRequest() {
        synchronized (requestMap) {
            final Pair<File, Long> nextRequest;
            if (!requestMap.isEmpty()) {
                File file = requestMap.keySet().iterator().next();
                Long newLastModifiedTime = requestMap.remove(file);
                nextRequest = Pair.of(file, newLastModifiedTime);
            } else {
                nextRequest = null;
                running = false;
            }
            return nextRequest;
        }
    }
}