com.hs.mail.imap.schedule.MessageCompressor.java Source code

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Here is the source code for com.hs.mail.imap.schedule.MessageCompressor.java

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/*
 * Copyright 2010 the original author or authors.
 * 
 *  Licensed under the Apache License, Version 2.0 (the "License");
 *  you may not use this file except in compliance with the License.
 *  You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 *  Unless required by applicable law or agreed to in writing, software
 *  distributed under the License is distributed on an "AS IS" BASIS,
 *  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 *  See the License for the specific language governing permissions and
 *  limitations under the License.
 */
package com.hs.mail.imap.schedule;

import java.io.File;
import java.io.FilenameFilter;
import java.io.IOException;
import java.util.Date;

import org.apache.commons.lang.time.DateFormatUtils;
import org.apache.commons.lang.time.DateUtils;
import org.apache.log4j.Logger;

import com.hs.mail.container.config.Config;
import com.hs.mail.util.FileUtils;

/**
 * 
 * @author Won Chul Doh
 * @since Oct 2, 2010
 *
 */
public class MessageCompressor {

    static Logger logger = Logger.getLogger(MessageCompressor.class);

    private static final String DOT_GZIP_EXTENSION = "." + FileUtils.GZIP_EXTENSION;
    private static final String COMPRESSED = ".compressed";

    public MessageCompressor() {
        super();
    }

    public void compress(String prop, long timeLimit) {
        Date base = ScheduleUtils.getDateBefore(prop);
        if (base != null) {
            Date start = getStartDate(base);
            if (start != null) {
                Date date = start;
                if (logger.isDebugEnabled()) {
                    logger.debug("Compressing directories from " + DateFormatUtils.ISO_DATE_FORMAT.format(start)
                            + " to " + DateFormatUtils.ISO_DATE_FORMAT.format(base));
                }
                while (date.before(base) && System.currentTimeMillis() < timeLimit) {
                    compressDirectories(date, timeLimit);
                    date = DateUtils.addDays(date, 1);
                }
            }
        }
    }

    public static File getDataDirectory(Date date, long physmessageid) {
        return new File(Config.getDataDirectory(), Config.getSubDirectory(date, physmessageid));
    }

    private Date getStartDate(Date date) {
        while (true) {
            File dir = getDataDirectory(date, 0).getParentFile();
            if (dir.exists()) {
                File[] subdirs = dir.listFiles();
                for (int i = 0; i < subdirs.length; i++) {
                    if (new File(subdirs[i], COMPRESSED).exists()) {
                        return date;
                    }
                }
            } else if (!dir.getParentFile().getParentFile().exists()) {
                return DateUtils.addDays(date, 1);
            }
            date = DateUtils.addDays(date, -1);
        }
    }

    private void compressDirectories(Date date, long timeLimit) {
        File directory = getDataDirectory(date, 0).getParentFile();
        if (directory.exists()) {
            File[] subdirs = directory.listFiles();
            for (int i = 0; i < subdirs.length && System.currentTimeMillis() < timeLimit; i++) {
                if (!new File(subdirs[i], COMPRESSED).exists()) {
                    if (logger.isDebugEnabled()) {
                        logger.debug("Start compressing " + subdirs[i].getAbsolutePath());
                    }
                    compressDirectory(subdirs[i]);
                }
            }
        }
    }

    private void compressDirectory(File directory) {
        File[] files = directory.listFiles(new FilenameFilter() {
            public boolean accept(File dir, String name) {
                return !name.endsWith(DOT_GZIP_EXTENSION);
            }
        });
        for (int i = 0; i < files.length; i++) {
            compressFile(files[i]);
        }
        FileUtils.createNewFile(new File(directory, COMPRESSED));
    }

    private void compressFile(File srcFile) {
        File destFile = null;
        try {
            destFile = new File(srcFile.getCanonicalPath() + DOT_GZIP_EXTENSION);
            FileUtils.compress(srcFile, destFile);
            srcFile.delete();
        } catch (IOException e) {
            if (srcFile.exists() && destFile != null && destFile.exists()) {
                destFile.delete();
            }
        }
    }

}