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    private final int bufferSize;
045
046    protected FileManager(final String fileName, final OutputStream os, final boolean append, final boolean locking,
047            final String advertiseURI, final Layout<? extends Serializable> layout, final int bufferSize) {
048        super(os, fileName, layout);
049        this.isAppend = append;
050        this.isLocking = locking;
051        this.advertiseURI = advertiseURI;
052        this.bufferSize = bufferSize;
053    }
054
055    /**
056     * Returns the FileManager.
057     * @param fileName The name of the file to manage.
058     * @param append true if the file should be appended to, false if it should be overwritten.
059     * @param locking true if the file should be locked while writing, false otherwise.
060     * @param bufferedIo true if the contents should be buffered as they are written.
061     * @param advertiseUri the URI to use when advertising the file
062     * @param layout The layout
063     * @param bufferSize buffer size for buffered IO
064     * @return A FileManager for the File.
065     */
066    public static FileManager getFileManager(final String fileName, final boolean append, boolean locking,
067            final boolean bufferedIo, final String advertiseUri, final Layout<? extends Serializable> layout,
068            final int bufferSize) {
069
070        if (locking && bufferedIo) {
071            locking = false;
072        }
073        return (FileManager) getManager(fileName, new FactoryData(append, locking, bufferedIo, bufferSize,
074                advertiseUri, layout), FACTORY);
075    }
076
077    @Override
078    protected synchronized void write(final byte[] bytes, final int offset, final int length)  {
079
080        if (isLocking) {
081            final FileChannel channel = ((FileOutputStream) getOutputStream()).getChannel();
082            try {
083                /* Lock the whole file. This could be optimized to only lock from the current file
084                   position. Note that locking may be advisory on some systems and mandatory on others,
085                   so locking just from the current position would allow reading on systems where
086                   locking is mandatory.  Also, Java 6 will throw an exception if the region of the
087                   file is already locked by another FileChannel in the same JVM. Hopefully, that will
088                   be avoided since every file should have a single file manager - unless two different
089                   files strings are configured that somehow map to the same file.*/
090                final FileLock lock = channel.lock(0, Long.MAX_VALUE, false);
091                try {
092                    super.write(bytes, offset, length);
093                } finally {
094                    lock.release();
095                }
096            } catch (final IOException ex) {
097                throw new AppenderLoggingException("Unable to obtain lock on " + getName(), ex);
098            }
099
100        } else {
101            super.write(bytes, offset, length);
102        }
103    }
104
105    /**
106     * Returns the name of the File being managed.
107     * @return The name of the File being managed.
108     */
109    public String getFileName() {
110        return getName();
111    }
112
113    /**
114     * Returns the append status.
115     * @return true if the file will be appended to, false if it is overwritten.
116     */
117    public boolean isAppend() {
118        return isAppend;
119    }
120
121    /**
122     * Returns the lock status.
123     * @return true if the file will be locked when writing, false otherwise.
124     */
125    public boolean isLocking() {
126        return isLocking;
127    }
128    
129    /**
130     * Returns the buffer size to use if the appender was configured with BufferedIO=true, otherwise returns a negative
131     * number.
132     * @return the buffer size, or a negative number if the output stream is not buffered
133     */
134    public int getBufferSize() {
135        return bufferSize;
136    }
137
138    /**
139     * FileManager's content format is specified by: <code>Key: "fileURI" Value: provided "advertiseURI" param</code>.
140     *
141     * @return Map of content format keys supporting FileManager
142     */
143    @Override
144    public Map<String, String> getContentFormat() {
145        final Map<String, String> result = new HashMap<String, String>(super.getContentFormat());
146        result.put("fileURI", advertiseURI);
147        return result;
148    }
149
150    /**
151     * Factory Data.
152     */
153    private static class FactoryData {
154        private final boolean append;
155        private final boolean locking;
156        private final boolean bufferedIO;
157        private final int bufferSize;
158        private final String advertiseURI;
159        private final Layout<? extends Serializable> layout;
160
161        /**
162         * Constructor.
163         * @param append Append status.
164         * @param locking Locking status.
165         * @param bufferedIO Buffering flag.
166         * @param bufferSize Buffer size.
167         * @param advertiseURI the URI to use when advertising the file
168         */
169        public FactoryData(final boolean append, final boolean locking, final boolean bufferedIO, final int bufferSize,
170                final String advertiseURI, final Layout<? extends Serializable> layout) {
171            this.append = append;
172            this.locking = locking;
173            this.bufferedIO = bufferedIO;
174            this.bufferSize = bufferSize;
175            this.advertiseURI = advertiseURI;
176            this.layout = layout;
177        }
178    }
179
180    /**
181     * Factory to create a FileManager.
182     */
183    private static class FileManagerFactory implements ManagerFactory<FileManager, FactoryData> {
184
185        /**
186         * Create a FileManager.
187         * @param name The name of the File.
188         * @param data The FactoryData
189         * @return The FileManager for the File.
190         */
191        @Override
192        public FileManager createManager(final String name, final FactoryData data) {
193            final File file = new File(name);
194            final File parent = file.getParentFile();
195            if (null != parent && !parent.exists()) {
196                parent.mkdirs();
197            }
198
199            OutputStream os;
200            try {
201                os = new FileOutputStream(name, data.append);
202                int bufferSize = data.bufferSize;
203                if (data.bufferedIO) {
204                    os = new BufferedOutputStream(os, bufferSize);
205                } else {
206                    bufferSize = -1; // signals to RollingFileManager not to use BufferedOutputStream
207                }
208                return new FileManager(name, os, data.append, data.locking, data.advertiseURI, data.layout, bufferSize);
209            } catch (final FileNotFoundException ex) {
210                LOGGER.error("FileManager (" + name + ") " + ex);
211            }
212            return null;
213        }
214    }
215
216}