    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    package org.apache.logging.log4j.core.appender;
    018
    019    import java.io.BufferedOutputStream;
    020    import java.io.File;
    021    import java.io.FileNotFoundException;
    022    import java.io.FileOutputStream;
    023    import java.io.IOException;
    024    import java.io.OutputStream;
    025    import java.io.Serializable;
    026    import java.nio.channels.FileChannel;
    027    import java.nio.channels.FileLock;
    028    import java.util.HashMap;
    029    import java.util.Map;
    030
    031    import org.apache.logging.log4j.core.Layout;
    032
    033
    034    /**
    035     * Manages actual File I/O for File Appenders.
    036     */
    037    public 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    }