001/*
002 * The contents of this file are subject to the terms of the Common Development and
003 * Distribution License (the License). You may not use this file except in compliance with the
004 * License.
005 *
006 * You can obtain a copy of the License at legal/CDDLv1.0.txt. See the License for the
007 * specific language governing permission and limitations under the License.
008 *
009 * When distributing Covered Software, include this CDDL Header Notice in each file and include
010 * the License file at legal/CDDLv1.0.txt. If applicable, add the following below the CDDL
011 * Header, with the fields enclosed by brackets [] replaced by your own identifying
012 * information: "Portions copyright [year] [name of copyright owner]".
013 *
014 * Copyright 2015-2016 ForgeRock AS.
015 */
016package org.forgerock.audit.retention;
017
018import java.io.File;
019import java.util.Collections;
020import java.util.Comparator;
021import java.util.LinkedList;
022import java.util.List;
023
024import org.forgerock.audit.util.LastModifiedTimeFileComparator;
025
026/**
027 * A {@link RetentionPolicy} that will retain/delete log files based off the total disk space used.
028 */
029public class DiskSpaceUsedRetentionPolicy implements RetentionPolicy {
030    private final long maxDiskSpaceToUse;
031    private final Comparator<File> comparator = new LastModifiedTimeFileComparator();
032
033    /**
034     * Constructs a {@link DiskSpaceUsedRetentionPolicy} with a given maximum of disk space to use in bytes.
035     * @param maxDiskSpaceToUse The maximum amount of disk space the historical audit files can occupy.
036     */
037    public DiskSpaceUsedRetentionPolicy(final long maxDiskSpaceToUse) {
038        this.maxDiskSpaceToUse = maxDiskSpaceToUse;
039    }
040
041    @Override
042    public List<File> deleteFiles(FileNamingPolicy fileNamingPolicy) {
043        final List<File> archivedFiles = fileNamingPolicy.listFiles();
044        long currentDiskSpaceUsed = 0L;
045        for (final File file: archivedFiles) {
046            currentDiskSpaceUsed += file.length();
047        }
048
049        if (currentDiskSpaceUsed <= maxDiskSpaceToUse) {
050            return Collections.emptyList();
051        }
052
053        final long freeSpaceNeeded = currentDiskSpaceUsed - maxDiskSpaceToUse;
054        Collections.sort(archivedFiles, comparator);
055
056        long freedSpace = 0L;
057        List<File> filesToDelete = new LinkedList<>();
058        for (File file : archivedFiles) {
059            filesToDelete.add(file);
060            freedSpace += file.length();
061            if (freedSpace >= freeSpaceNeeded) {
062                break;
063            }
064        }
065
066        return filesToDelete;
067    }
068}