001/*
002 * Licensed to the Apache Software Foundation (ASF) under one or more
003 * contributor license agreements. See the NOTICE file distributed with
004 * this work for additional information regarding copyright ownership.
005 * The ASF licenses this file to You under the Apache license, Version 2.0
006 * (the "License"); you may not use this file except in compliance with
007 * the License. You may obtain a copy of the License at
008 *
009 *      http://www.apache.org/licenses/LICENSE-2.0
010 *
011 * Unless required by applicable law or agreed to in writing, software
012 * distributed under the License is distributed on an "AS IS" BASIS,
013 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
014 * See the license for the specific language governing permissions and
015 * limitations under the license.
016 */
017
018package org.apache.logging.log4j.core.appender.rolling.action;
019
020import org.apache.logging.log4j.core.config.plugins.Plugin;
021import org.apache.logging.log4j.core.config.plugins.PluginAttribute;
022import org.apache.logging.log4j.core.config.plugins.PluginFactory;
023
024/**
025 * {@link PathSorter} that sorts path by their LastModified attribute.
026 */
027@Plugin(name = "SortByModificationTime", category = "Core", printObject = true)
028public class PathSortByModificationTime implements PathSorter {
029
030    private final boolean recentFirst;
031    private final int multiplier;
032
033    /**
034     * Constructs a new SortByModificationTime sorter.
035     * 
036     * @param recentFirst if true, most recently modified paths should come first
037     */
038    public PathSortByModificationTime(final boolean recentFirst) {
039        this.recentFirst = recentFirst;
040        this.multiplier = recentFirst ? 1 : -1;
041    }
042
043    /**
044     * Create a PathSorter that sorts by lastModified time.
045     * 
046     * @param recentFirst if true, most recently modified paths should come first.
047     * @return A PathSorter.
048     */
049    @PluginFactory
050    public static PathSorter createSorter( //
051            @PluginAttribute(value = "recentFirst", defaultBoolean = true) final boolean recentFirst) {
052        return new PathSortByModificationTime(recentFirst);
053    }
054
055    /**
056     * Returns whether this sorter sorts recent files first.
057     * 
058     * @return whether this sorter sorts recent files first
059     */
060    public boolean isRecentFirst() {
061        return recentFirst;
062    }
063
064    /*
065     * (non-Javadoc)
066     * 
067     * @see java.util.Comparator#compare(java.lang.Object, java.lang.Object)
068     */
069    @Override
070    public int compare(final PathWithAttributes path1, final PathWithAttributes path2) {
071        final long lastModified1 = path1.getAttributes().lastModifiedTime().toMillis();
072        final long lastModified2 = path2.getAttributes().lastModifiedTime().toMillis();
073        int result = Long.signum(lastModified2 - lastModified1);
074        if (result == 0) { // if same time compare paths lexicographically
075            try {
076                // assuming paths contain counters and dates, use reverse lexicographical order:
077                // 20151129 before 20151128, path-2.log before path-1.log
078                result = path2.getPath().compareTo(path1.getPath());
079            } catch (final ClassCastException ex) {
080                result = path2.getPath().toString().compareTo(path1.getPath().toString());
081            }
082        }
083        return multiplier * result;
084    }
085}