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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 int BIT_POSITION_1GB = 30; // 2^30 ~= 1GB
46      private static final int MAX_REGION_LENGTH = 1 << BIT_POSITION_1GB;
47      private static final int MIN_REGION_LENGTH = 256;
48  
49      private final String fileName;
50      private Object advertisement;
51      private final Advertiser advertiser;
52  
53      private MemoryMappedFileAppender(final String name, final Layout<? extends Serializable> layout,
54              final Filter filter, final MemoryMappedFileManager manager, final String filename,
55              final boolean ignoreExceptions, final boolean immediateFlush, final Advertiser advertiser) {
56          super(name, layout, filter, ignoreExceptions, immediateFlush, manager);
57          if (advertiser != null) {
58              final Map<String, String> configuration = new HashMap<>(layout.getContentFormat());
59              configuration.putAll(manager.getContentFormat());
60              configuration.put("contentType", layout.getContentType());
61              configuration.put("name", name);
62              advertisement = advertiser.advertise(configuration);
63          }
64          this.fileName = filename;
65          this.advertiser = advertiser;
66      }
67  
68      @Override
69      public void stop() {
70          super.stop();
71          if (advertiser != null) {
72              advertiser.unadvertise(advertisement);
73          }
74      }
75  
76      /**
77       * Write the log entry rolling over the file when required.
78       *
79       * @param event The LogEvent.
80       */
81      @Override
82      public void append(final LogEvent event) {
83  
84          // Leverage the nice batching behaviour of async Loggers/Appenders:
85          // we can signal the file manager that it needs to flush the buffer
86          // to disk at the end of a batch.
87          // From a user's point of view, this means that all log events are
88          // _always_ available in the log file, without incurring the overhead
89          // of immediateFlush=true.
90          getManager().setEndOfBatch(event.isEndOfBatch()); // FIXME manager's EndOfBatch threadlocal can be deleted
91          super.append(event); // TODO should only call force() if immediateFlush && endOfBatch?
92      }
93  
94      /**
95       * Returns the file name this appender is associated with.
96       *
97       * @return The File name.
98       */
99      public String getFileName() {
100         return this.fileName;
101     }
102 
103     /**
104      * Returns the length of the memory mapped region.
105      *
106      * @return the length of the memory mapped region
107      */
108     public int getRegionLength() {
109         return getManager().getRegionLength();
110     }
111 
112     /**
113      * Create a Memory Mapped File Appender.
114      *
115      * @param fileName The name and path of the file.
116      * @param append "True" if the file should be appended to, "false" if it should be overwritten. The default is
117      *            "true".
118      * @param name The name of the Appender.
119      * @param immediateFlush "true" if the contents should be flushed on every write, "false" otherwise. The default is
120      *            "true".
121      * @param regionLengthStr The buffer size, defaults to {@value MemoryMappedFileManager#DEFAULT_REGION_LENGTH}.
122      * @param ignore If {@code "true"} (default) exceptions encountered when appending events are logged; otherwise they
123      *            are propagated to the caller.
124      * @param layout The layout to use to format the event. If no layout is provided the default PatternLayout will be
125      *            used.
126      * @param filter The filter, if any, to use.
127      * @param advertise "true" if the appender configuration should be advertised, "false" otherwise.
128      * @param advertiseURI The advertised URI which can be used to retrieve the file contents.
129      * @param config The Configuration.
130      * @return The FileAppender.
131      */
132     @PluginFactory
133     public static MemoryMappedFileAppender createAppender(
134 // @formatter:off
135             @PluginAttribute("fileName") final String fileName, //
136             @PluginAttribute("append") final String append, //
137             @PluginAttribute("name") final String name, //
138             @PluginAttribute("immediateFlush") final String immediateFlush, //
139             @PluginAttribute("regionLength") final String regionLengthStr, //
140             @PluginAttribute("ignoreExceptions") final String ignore, //
141             @PluginElement("Layout") Layout<? extends Serializable> layout, //
142             @PluginElement("Filter") final Filter filter, //
143             @PluginAttribute("advertise") final String advertise, //
144             @PluginAttribute("advertiseURI") final String advertiseURI, //
145             @PluginConfiguration final Configuration config) {
146         // @formatter:on
147 
148         final boolean isAppend = Booleans.parseBoolean(append, true);
149         final boolean isForce = Booleans.parseBoolean(immediateFlush, false);
150         final boolean ignoreExceptions = Booleans.parseBoolean(ignore, true);
151         final boolean isAdvertise = Boolean.parseBoolean(advertise);
152         final int regionLength = Integers.parseInt(regionLengthStr, MemoryMappedFileManager.DEFAULT_REGION_LENGTH);
153         final int actualRegionLength = determineValidRegionLength(name, regionLength);
154 
155         if (name == null) {
156             LOGGER.error("No name provided for MemoryMappedFileAppender");
157             return null;
158         }
159 
160         if (fileName == null) {
161             LOGGER.error("No filename provided for MemoryMappedFileAppender with name " + name);
162             return null;
163         }
164         if (layout == null) {
165             layout = PatternLayout.createDefaultLayout();
166         }
167         final MemoryMappedFileManager manager = MemoryMappedFileManager.getFileManager(fileName, isAppend, isForce,
168                 actualRegionLength, advertiseURI, layout);
169         if (manager == null) {
170             return null;
171         }
172 
173         return new MemoryMappedFileAppender(name, layout, filter, manager, fileName, ignoreExceptions, false,
174                 isAdvertise ? config.getAdvertiser() : null);
175     }
176 
177     /**
178      * Converts the specified region length to a valid value.
179      */
180     private static int determineValidRegionLength(final String name, final int regionLength) {
181         if (regionLength > MAX_REGION_LENGTH) {
182             LOGGER.info("MemoryMappedAppender[{}] Reduced region length from {} to max length: {}", name, regionLength,
183                     MAX_REGION_LENGTH);
184             return MAX_REGION_LENGTH;
185         }
186         if (regionLength < MIN_REGION_LENGTH) {
187             LOGGER.info("MemoryMappedAppender[{}] Expanded region length from {} to min length: {}", name, regionLength,
188                     MIN_REGION_LENGTH);
189             return MIN_REGION_LENGTH;
190         }
191         final int result = Integers.ceilingNextPowerOfTwo(regionLength);
192         if (regionLength != result) {
193             LOGGER.info("MemoryMappedAppender[{}] Rounded up region length from {} to next power of two: {}", name,
194                     regionLength, result);
195         }
196         return result;
197     }
198 }