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.LinkedList;
021import java.util.List;
022
023/**
024 * Created a size based file retention policy. This policy stores a set number of archived files.
025 */
026public class SizeBasedRetentionPolicy implements RetentionPolicy {
027    private final int maxNumberOfFiles;
028
029    /**
030     * Constructs a SizeBasedRetentionPolicy with a given maximum number of archived files. A negative value
031     * disables pruning of old archive files.
032     * @param maxNumberOfFiles The maximum number of archive files to keep. A negative value will disable
033     *                         pruning old archive files.
034     */
035    public SizeBasedRetentionPolicy(final int maxNumberOfFiles) {
036        this.maxNumberOfFiles = maxNumberOfFiles;
037    }
038
039    @Override
040    public List<File> deleteFiles(FileNamingPolicy fileNamingPolicy) {
041        final List<File> managedArchivedFiles = fileNamingPolicy.listFiles();
042        final int numberOfManagedArchiveFiles = managedArchivedFiles.size();
043        if (maxNumberOfFiles <= 0 || numberOfManagedArchiveFiles <= maxNumberOfFiles) {
044            return Collections.emptyList();
045        } else {
046            final List<File> filesToDelete =
047                    new LinkedList<>(managedArchivedFiles.subList(0, numberOfManagedArchiveFiles - maxNumberOfFiles));
048            return filesToDelete;
049        }
050    }
051}