View Javadoc

    1   /*
    2    * Licensed to the Apache Software Foundation (ASF) under one or more
    3    * contributor license agreements. See the NOTICE file distributed with
    4    * this work for additional information regarding copyright ownership.
    5    * The ASF licenses this file to You under the Apache license, Version 2.0
    6    * (the "License"); you may not use this file except in compliance with
    7    * the License. You may obtain a copy of the License at
    8    *
    9    *      http://www.apache.org/licenses/LICENSE-2.0
    10   *
    11   * Unless required by applicable law or agreed to in writing, software
    12   * distributed under the License is distributed on an "AS IS" BASIS,
    13   * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    14   * See the license for the specific language governing permissions and
    15   * limitations under the license.
    16   */
    17  package org.apache.logging.log4j.core.appender;
    18
    19  import java.io.Serializable;
    20  import java.util.HashMap;
    21  import java.util.Map;
    22
    23  import org.apache.logging.log4j.core.Filter;
    24  import org.apache.logging.log4j.core.Layout;
    25  import org.apache.logging.log4j.core.LogEvent;
    26  import org.apache.logging.log4j.core.config.Configuration;
    27  import org.apache.logging.log4j.core.config.plugins.Plugin;
    28  import org.apache.logging.log4j.core.config.plugins.PluginAttribute;
    29  import org.apache.logging.log4j.core.config.plugins.PluginConfiguration;
    30  import org.apache.logging.log4j.core.config.plugins.PluginElement;
    31  import org.apache.logging.log4j.core.config.plugins.PluginFactory;
    32  import org.apache.logging.log4j.core.layout.PatternLayout;
    33  import org.apache.logging.log4j.core.net.Advertiser;
    34  import org.apache.logging.log4j.core.util.Booleans;
    35  import org.apache.logging.log4j.core.util.Integers;
    36
    37  /**
    38   * Memory Mapped File Appender.
    39   *
    40   * @since 2.1
    41   */
    42  @Plugin(name = "MemoryMappedFile", category = "Core", elementType = "appender", printObject = true)
    43  public final class MemoryMappedFileAppender extends AbstractOutputStreamAppender<MemoryMappedFileManager> {
    44
    45      private static final long serialVersionUID = 1L;
    46
    47      private static final int MAX_REGION_LENGTH = 1 << 30; // 1GB
    48      private static final int MIN_REGION_LENGTH = 256;
    49
    50      private final String fileName;
    51      private Object advertisement;
    52      private final Advertiser advertiser;
    53
    54      private MemoryMappedFileAppender(final String name, final Layout<? extends Serializable> layout,
    55              final Filter filter, final MemoryMappedFileManager manager, final String filename,
    56              final boolean ignoreExceptions, final boolean immediateFlush, final Advertiser advertiser) {
    57          super(name, layout, filter, ignoreExceptions, immediateFlush, manager);
    58          if (advertiser != null) {
    59              final Map<String, String> configuration = new HashMap<String, String>(layout.getContentFormat());
    60              configuration.putAll(manager.getContentFormat());
    61              configuration.put("contentType", layout.getContentType());
    62              configuration.put("name", name);
    63              advertisement = advertiser.advertise(configuration);
    64          }
    65          this.fileName = filename;
    66          this.advertiser = advertiser;
    67      }
    68
    69      @Override
    70      public void stop() {
    71          super.stop();
    72          if (advertiser != null) {
    73              advertiser.unadvertise(advertisement);
    74          }
    75      }
    76
    77      /**
    78       * Write the log entry rolling over the file when required.
    79       *
    80       * @param event The LogEvent.
    81       */
    82      @Override
    83      public void append(final LogEvent event) {
    84
    85          // Leverage the nice batching behaviour of async Loggers/Appenders:
    86          // we can signal the file manager that it needs to flush the buffer
    87          // to disk at the end of a batch.
    88          // From a user's point of view, this means that all log events are
    89          // _always_ available in the log file, without incurring the overhead
    90          // of immediateFlush=true.
    91          getManager().setEndOfBatch(event.isEndOfBatch());
    92          super.append(event);
    93      }
    94
    95      /**
    96       * Returns the file name this appender is associated with.
    97       *
    98       * @return The File name.
    99       */
    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 }