001/*
002 * Logback: the reliable, generic, fast and flexible logging framework.
003 * Copyright (C) 1999-2026, QOS.ch. All rights reserved.
004 *
005 * This program and the accompanying materials are dual-licensed under
006 * either the terms of the Eclipse Public License v2.0 as published by
007 * the Eclipse Foundation
008 *
009 *   or (per the licensee's choosing)
010 *
011 * under the terms of the GNU Lesser General Public License version 2.1
012 * as published by the Free Software Foundation.
013 */
014
015package ch.qos.logback.core.rolling.helper;
016
017import ch.qos.logback.core.status.ErrorStatus;
018import ch.qos.logback.core.status.WarnStatus;
019
020import java.io.File;
021import java.io.FileInputStream;
022import java.io.FileOutputStream;
023import java.util.zip.GZIPOutputStream;
024
025import static ch.qos.logback.core.rolling.helper.CompressionMode.GZ_SUFFIX;
026
027public class GZCompressionStrategy extends CompressionStrategyBase {
028
029
030    @Override
031    public void compress(String originalFileName, String compressedFileName, String innerEntryName) {
032
033        File file2gz = new File(originalFileName);
034
035        if (!file2gz.exists()) {
036            addStatus(new WarnStatus("The file to compress named [" + originalFileName + "] does not exist.", this));
037
038            return;
039        }
040
041        if (!compressedFileName.endsWith(GZ_SUFFIX)) {
042            compressedFileName = compressedFileName + GZ_SUFFIX;
043        }
044
045        File gzedFile = new File(compressedFileName);
046
047        if (gzedFile.exists()) {
048            addWarn("The target compressed file named [" + compressedFileName + "] exist already. Aborting file compression.");
049            return;
050        }
051
052        addInfo("GZ compressing [" + file2gz + "] as [" + gzedFile + "]");
053        createMissingTargetDirsIfNecessary(gzedFile);
054        boolean compressionSucceeded = false;
055        try (FileInputStream fis = new FileInputStream(originalFileName);
056             GZIPOutputStream gzos = new GZIPOutputStream(new FileOutputStream(compressedFileName), BUFFER_SIZE)) {
057
058            byte[] inbuf = new byte[BUFFER_SIZE];
059            int n;
060
061            while ((n = fis.read(inbuf)) != -1) {
062                gzos.write(inbuf, 0, n);
063            }
064
065            compressionSucceeded = true;
066            addInfo("Done GZ compressing [" + file2gz + "] as [" + gzedFile + "]");
067        } catch (Exception e) {
068            addStatus(new ErrorStatus("Error occurred while compressing [" + originalFileName + "] into [" + compressedFileName + "].", this, e));
069        }
070
071
072        // Delete the original only after successful compression so a failure leaves it intact.
073        if (compressionSucceeded) {
074            if (!file2gz.delete()) {
075                addStatus(new WarnStatus("Could not delete [" + originalFileName + "].", this));
076            }
077        } else {
078            addStatus(new WarnStatus("Compression of [" + originalFileName + "] failed. Original file left intact.", this));
079        }
080
081    }
082
083}