    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.Serializable;
    020    import java.util.HashMap;
    021    import java.util.Map;
    022
    023    import org.apache.logging.log4j.core.Filter;
    024    import org.apache.logging.log4j.core.Layout;
    025    import org.apache.logging.log4j.core.LogEvent;
    026    import org.apache.logging.log4j.core.config.Configuration;
    027    import org.apache.logging.log4j.core.config.plugins.Plugin;
    028    import org.apache.logging.log4j.core.config.plugins.PluginAttribute;
    029    import org.apache.logging.log4j.core.config.plugins.PluginConfiguration;
    030    import org.apache.logging.log4j.core.config.plugins.PluginElement;
    031    import org.apache.logging.log4j.core.config.plugins.PluginFactory;
    032    import org.apache.logging.log4j.core.layout.PatternLayout;
    033    import org.apache.logging.log4j.core.net.Advertiser;
    034    import org.apache.logging.log4j.core.util.Booleans;
    035    import org.apache.logging.log4j.core.util.Integers;
    036
    037    /**
    038     * Memory Mapped File Appender.
    039     *
    040     * @since 2.1
    041     */
    042    @Plugin(name = "MemoryMappedFile", category = "Core", elementType = "appender", printObject = true)
    043    public final class MemoryMappedFileAppender extends AbstractOutputStreamAppender<MemoryMappedFileManager> {
    044
    045        private static final long serialVersionUID = 1L;
    046
    047        private static final int MAX_REGION_LENGTH = 1 << 30; // 1GB
    048        private static final int MIN_REGION_LENGTH = 256;
    049
    050        private final String fileName;
    051        private Object advertisement;
    052        private final Advertiser advertiser;
    053
    054        private MemoryMappedFileAppender(final String name, final Layout<? extends Serializable> layout,
    055                final Filter filter, final MemoryMappedFileManager manager, final String filename,
    056                final boolean ignoreExceptions, final boolean immediateFlush, final Advertiser advertiser) {
    057            super(name, layout, filter, ignoreExceptions, immediateFlush, manager);
    058            if (advertiser != null) {
    059                final Map<String, String> configuration = new HashMap<String, String>(layout.getContentFormat());
    060                configuration.putAll(manager.getContentFormat());
    061                configuration.put("contentType", layout.getContentType());
    062                configuration.put("name", name);
    063                advertisement = advertiser.advertise(configuration);
    064            }
    065            this.fileName = filename;
    066            this.advertiser = advertiser;
    067        }
    068
    069        @Override
    070        public void stop() {
    071            super.stop();
    072            if (advertiser != null) {
    073                advertiser.unadvertise(advertisement);
    074            }
    075        }
    076
    077        /**
    078         * Write the log entry rolling over the file when required.
    079         *
    080         * @param event The LogEvent.
    081         */
    082        @Override
    083        public void append(final LogEvent event) {
    084
    085            // Leverage the nice batching behaviour of async Loggers/Appenders:
    086            // we can signal the file manager that it needs to flush the buffer
    087            // to disk at the end of a batch.
    088            // From a user's point of view, this means that all log events are
    089            // _always_ available in the log file, without incurring the overhead
    090            // of immediateFlush=true.
    091            getManager().setEndOfBatch(event.isEndOfBatch());
    092            super.append(event);
    093        }
    094
    095        /**
    096         * Returns the file name this appender is associated with.
    097         *
    098         * @return The File name.
    099         */
    100        public String getFileName() {
    101            return this.fileName;
    102        }
    103
    104        /**
    105         * Returns the length of the memory mapped region.
    106         *
    107         * @return the length of the memory mapped region
    108         */
    109        public int getRegionLength() {
    110            return getManager().getRegionLength();
    111        }
    112
    113        /**
    114         * Create a Memory Mapped File Appender.
    115         *
    116         * @param fileName The name and path of the file.
    117         * @param append "True" if the file should be appended to, "false" if it should be overwritten. The default is
    118         *            "true".
    119         * @param name The name of the Appender.
    120         * @param immediateFlush "true" if the contents should be flushed on every write, "false" otherwise. The default is
    121         *            "true".
    122         * @param regionLengthStr The buffer size, defaults to {@value MemoryMappedFileManager#DEFAULT_REGION_LENGTH}.
    123         * @param ignore If {@code "true"} (default) exceptions encountered when appending events are logged; otherwise they
    124         *            are propagated to the caller.
    125         * @param layout The layout to use to format the event. If no layout is provided the default PatternLayout will be
    126         *            used.
    127         * @param filter The filter, if any, to use.
    128         * @param advertise "true" if the appender configuration should be advertised, "false" otherwise.
    129         * @param advertiseURI The advertised URI which can be used to retrieve the file contents.
    130         * @param config The Configuration.
    131         * @return The FileAppender.
    132         */
    133        @PluginFactory
    134        public static MemoryMappedFileAppender createAppender(
    135    // @formatter:off
    136                @PluginAttribute("fileName") final String fileName, //
    137                @PluginAttribute("append") final String append, //
    138                @PluginAttribute("name") final String name, //
    139                @PluginAttribute("immediateFlush") final String immediateFlush, //
    140                @PluginAttribute("regionLength") final String regionLengthStr, //
    141                @PluginAttribute("ignoreExceptions") final String ignore, //
    142                @PluginElement("Layout") Layout<? extends Serializable> layout, //
    143                @PluginElement("Filter") final Filter filter, //
    144                @PluginAttribute("advertise") final String advertise, //
    145                @PluginAttribute("advertiseURI") final String advertiseURI, //
    146                @PluginConfiguration final Configuration config) {
    147            // @formatter:on
    148
    149            final boolean isAppend = Booleans.parseBoolean(append, true);
    150            final boolean isForce = Booleans.parseBoolean(immediateFlush, false);
    151            final boolean ignoreExceptions = Booleans.parseBoolean(ignore, true);
    152            final boolean isAdvertise = Boolean.parseBoolean(advertise);
    153            final int regionLength = Integers.parseInt(regionLengthStr, MemoryMappedFileManager.DEFAULT_REGION_LENGTH);
    154            final int actualRegionLength = determineValidRegionLength(name, regionLength);
    155
    156            if (name == null) {
    157                LOGGER.error("No name provided for MemoryMappedFileAppender");
    158                return null;
    159            }
    160
    161            if (fileName == null) {
    162                LOGGER.error("No filename provided for MemoryMappedFileAppender with name " + name);
    163                return null;
    164            }
    165            if (layout == null) {
    166                layout = PatternLayout.createDefaultLayout();
    167            }
    168            final MemoryMappedFileManager manager = MemoryMappedFileManager.getFileManager(fileName, isAppend, isForce,
    169                    actualRegionLength, advertiseURI, layout);
    170            if (manager == null) {
    171                return null;
    172            }
    173
    174            return new MemoryMappedFileAppender(name, layout, filter, manager, fileName, ignoreExceptions, isForce,
    175                    isAdvertise ? config.getAdvertiser() : null);
    176        }
    177
    178        /**
    179         * Converts the specified region length to a valid value.
    180         */
    181        private static int determineValidRegionLength(final String name, final int regionLength) {
    182            if (regionLength > MAX_REGION_LENGTH) {
    183                LOGGER.info("MemoryMappedAppender[{}] Reduced region length from {} to max length: {}", name, regionLength,
    184                        MAX_REGION_LENGTH);
    185                return MAX_REGION_LENGTH;
    186            }
    187            if (regionLength < MIN_REGION_LENGTH) {
    188                LOGGER.info("MemoryMappedAppender[{}] Expanded region length from {} to min length: {}", name, regionLength,
    189                        MIN_REGION_LENGTH);
    190                return MIN_REGION_LENGTH;
    191            }
    192            final int result = Integers.ceilingNextPowerOfTwo(regionLength);
    193            if (regionLength != result) {
    194                LOGGER.info("MemoryMappedAppender[{}] Rounded up region length from {} to next power of two: {}", name,
    195                        regionLength, result);
    196            }
    197            return result;
    198        }
    199    }