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 }