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    }