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 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 given a minimum amount of disk space the file system
028 * must contain.
029 */
030public class FreeDiskSpaceRetentionPolicy implements RetentionPolicy {
031
032    private final long minFreeSpaceRequired;
033    private final Comparator<File> comparator = new LastModifiedTimeFileComparator();
034
035    /**
036     * Constructs a {@link FreeDiskSpaceRetentionPolicy} given a minimum amount of disk space the file system must
037     * contain.
038     * @param minFreeSpaceRequired The minimum amount of free disk space the the file system must contain in bytes.
039     */
040    public FreeDiskSpaceRetentionPolicy(final long minFreeSpaceRequired) {
041        this.minFreeSpaceRequired = minFreeSpaceRequired;
042    }
043
044    @Override
045    public List<File> deleteFiles(FileNamingPolicy fileNamingPolicy) {
046        final List<File> archivedFiles = fileNamingPolicy.listFiles();
047        if (archivedFiles.isEmpty()) {
048            return Collections.emptyList();
049        }
050
051        final long freeSpace = archivedFiles.get(0).getFreeSpace();
052        if (freeSpace >= minFreeSpaceRequired) {
053            return Collections.emptyList();
054        }
055
056        final long freeSpaceNeeded = minFreeSpaceRequired - freeSpace;
057
058        Collections.sort(archivedFiles, comparator);
059
060        long freedSpace = 0L;
061        List<File> filesToDelete = new LinkedList<>();
062        for (File file : archivedFiles) {
063            filesToDelete.add(file);
064            freedSpace += file.length();
065            if (freedSpace >= freeSpaceNeeded) {
066                break;
067            }
068        }
069        return filesToDelete;
070    }
071}