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 */
017package org.apache.logging.log4j.core.appender;
018
019import java.io.BufferedOutputStream;
020import java.io.File;
021import java.io.FileNotFoundException;
022import java.io.FileOutputStream;
023import java.io.IOException;
024import java.io.OutputStream;
025import java.io.Serializable;
026import java.nio.channels.FileChannel;
027import java.nio.channels.FileLock;
028import java.util.HashMap;
029import java.util.Map;
030
031import org.apache.logging.log4j.core.Layout;
032
033
034/**
035 * Manages actual File I/O for File Appenders.
036 */
037public class FileManager extends OutputStreamManager {
038
039    private static final FileManagerFactory FACTORY = new FileManagerFactory();
040
041    private final boolean isAppend;
042    private final boolean isLocking;
043    private final String advertiseURI;
044
045    protected FileManager(final String fileName, final OutputStream os, final boolean append, final boolean locking,
046                          final String advertiseURI, final Layout<? extends Serializable> layout) {
047        super(os, fileName, layout);
048        this.isAppend = append;
049        this.isLocking = locking;
050        this.advertiseURI = advertiseURI;
051    }
052
053    /**
054     * Returns the FileManager.
055     * @param fileName The name of the file to manage.
056     * @param append true if the file should be appended to, false if it should be overwritten.
057     * @param locking true if the file should be locked while writing, false otherwise.
058     * @param bufferedIO true if the contents should be buffered as they are written.
059     * @param advertiseURI the URI to use when advertising the file
060     * @param layout The layout
061     * @param bufferSize buffer size for buffered IO
062     * @return A FileManager for the File.
063     */
064    public static FileManager getFileManager(final String fileName, final boolean append, boolean locking,
065            final boolean bufferedIO, final String advertiseURI, final Layout<? extends Serializable> layout,
066            final int bufferSize) {
067
068        if (locking && bufferedIO) {
069            locking = false;
070        }
071        return (FileManager) getManager(fileName, new FactoryData(append, locking, bufferedIO, bufferSize,
072                advertiseURI, layout), FACTORY);
073    }
074
075    @Override
076    protected synchronized void write(final byte[] bytes, final int offset, final int length)  {
077
078        if (isLocking) {
079            final FileChannel channel = ((FileOutputStream) getOutputStream()).getChannel();
080            try {
081                /* Lock the whole file. This could be optimized to only lock from the current file
082                   position. Note that locking may be advisory on some systems and mandatory on others,
083                   so locking just from the current position would allow reading on systems where
084                   locking is mandatory.  Also, Java 6 will throw an exception if the region of the
085                   file is already locked by another FileChannel in the same JVM. Hopefully, that will
086                   be avoided since every file should have a single file manager - unless two different
087                   files strings are configured that somehow map to the same file.*/
088                final FileLock lock = channel.lock(0, Long.MAX_VALUE, false);
089                try {
090                    super.write(bytes, offset, length);
091                } finally {
092                    lock.release();
093                }
094            } catch (final IOException ex) {
095                throw new AppenderLoggingException("Unable to obtain lock on " + getName(), ex);
096            }
097
098        } else {
099            super.write(bytes, offset, length);
100        }
101    }
102
103    /**
104     * Returns the name of the File being managed.
105     * @return The name of the File being managed.
106     */
107    public String getFileName() {
108        return getName();
109    }
110
111    /**
112     * Returns the append status.
113     * @return true if the file will be appended to, false if it is overwritten.
114     */
115    public boolean isAppend() {
116        return isAppend;
117    }
118
119    /**
120     * Returns the lock status.
121     * @return true if the file will be locked when writing, false otherwise.
122     */
123    public boolean isLocking() {
124        return isLocking;
125    }
126
127    /**
128     * FileManager's content format is specified by: <code>Key: "fileURI" Value: provided "advertiseURI" param</code>.
129     *
130     * @return Map of content format keys supporting FileManager
131     */
132    @Override
133    public Map<String, String> getContentFormat() {
134        final Map<String, String> result = new HashMap<String, String>(super.getContentFormat());
135        result.put("fileURI", advertiseURI);
136        return result;
137    }
138
139    /**
140     * Factory Data.
141     */
142    private static class FactoryData {
143        private final boolean append;
144        private final boolean locking;
145        private final boolean bufferedIO;
146        private final int bufferSize;
147        private final String advertiseURI;
148        private final Layout<? extends Serializable> layout;
149
150        /**
151         * Constructor.
152         * @param append Append status.
153         * @param locking Locking status.
154         * @param bufferedIO Buffering flag.
155         * @param bufferSize Buffer size.
156         * @param advertiseURI the URI to use when advertising the file
157         */
158        public FactoryData(final boolean append, final boolean locking, final boolean bufferedIO, final int bufferSize,
159                final String advertiseURI, final Layout<? extends Serializable> layout) {
160            this.append = append;
161            this.locking = locking;
162            this.bufferedIO = bufferedIO;
163            this.bufferSize = bufferSize;
164            this.advertiseURI = advertiseURI;
165            this.layout = layout;
166        }
167    }
168
169    /**
170     * Factory to create a FileManager.
171     */
172    private static class FileManagerFactory implements ManagerFactory<FileManager, FactoryData> {
173
174        /**
175         * Create a FileManager.
176         * @param name The name of the File.
177         * @param data The FactoryData
178         * @return The FileManager for the File.
179         */
180        @Override
181        public FileManager createManager(final String name, final FactoryData data) {
182            final File file = new File(name);
183            final File parent = file.getParentFile();
184            if (null != parent && !parent.exists()) {
185                parent.mkdirs();
186            }
187
188            OutputStream os;
189            try {
190                os = new FileOutputStream(name, data.append);
191                if (data.bufferedIO) {
192                    os = new BufferedOutputStream(os, data.bufferSize);
193                }
194                return new FileManager(name, os, data.append, data.locking, data.advertiseURI, data.layout);
195            } catch (final FileNotFoundException ex) {
196                LOGGER.error("FileManager (" + name + ") " + ex);
197            }
198            return null;
199        }
200    }
201
202}