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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.File;
20  import java.io.IOException;
21  import java.io.OutputStream;
22  import java.io.RandomAccessFile;
23  import java.io.Serializable;
24  import java.nio.ByteBuffer;
25  import java.util.HashMap;
26  import java.util.Map;
27  
28  import org.apache.logging.log4j.core.Layout;
29  
30  /**
31   * Extends OutputStreamManager but instead of using a buffered output stream,
32   * this class uses a {@code ByteBuffer} and a {@code RandomAccessFile} to do the
33   * I/O.
34   */
35  public class RandomAccessFileManager extends OutputStreamManager {
36      static final int DEFAULT_BUFFER_SIZE = 256 * 1024;
37  
38      private static final RandomAccessFileManagerFactory FACTORY = new RandomAccessFileManagerFactory();
39  
40      private final boolean isImmediateFlush;
41      private final String advertiseURI;
42      private final RandomAccessFile randomAccessFile;
43      private final ByteBuffer buffer;
44      private final ThreadLocal<Boolean> isEndOfBatch = new ThreadLocal<Boolean>();
45  
46      protected RandomAccessFileManager(final RandomAccessFile file,
47              final String fileName, final OutputStream os,
48              final boolean immediateFlush, int bufferSize,
49              final String advertiseURI, final Layout<? extends Serializable> layout) {
50          super(os, fileName, layout);
51          this.isImmediateFlush = immediateFlush;
52          this.randomAccessFile = file;
53          this.advertiseURI = advertiseURI;
54          this.isEndOfBatch.set(Boolean.FALSE);
55  
56          // TODO make buffer size configurable?
57          this.buffer = ByteBuffer.allocate(bufferSize);
58      }
59  
60      /**
61       * Returns the RandomAccessFileManager.
62       *
63       * @param fileName The name of the file to manage.
64       * @param append true if the file should be appended to, false if it should
65       *            be overwritten.
66       * @param isFlush true if the contents should be flushed to disk on every
67       *            write
68       * @param bufferSize The buffer size.
69       * @param advertiseURI the URI to use when advertising the file
70       * @param layout The layout.
71       * @return A RandomAccessFileManager for the File.
72       */
73      public static RandomAccessFileManager getFileManager(final String fileName, final boolean append,
74              final boolean isFlush, int bufferSize, final String advertiseURI,
75              final Layout<? extends Serializable> layout) {
76          return (RandomAccessFileManager) getManager(fileName, new FactoryData(append,
77                  isFlush, bufferSize, advertiseURI, layout), FACTORY);
78      }
79  
80      public Boolean isEndOfBatch() {
81          return isEndOfBatch.get();
82      }
83  
84      public void setEndOfBatch(final boolean isEndOfBatch) {
85          this.isEndOfBatch.set(Boolean.valueOf(isEndOfBatch));
86      }
87  
88      @Override
89      protected synchronized void write(final byte[] bytes, int offset, int length) {
90          super.write(bytes, offset, length); // writes to dummy output stream
91  
92          int chunk = 0;
93          do {
94              if (length > buffer.remaining()) {
95                  flush();
96              }
97              chunk = Math.min(length, buffer.remaining());
98              buffer.put(bytes, offset, chunk);
99              offset += chunk;
100             length -= chunk;
101         } while (length > 0);
102 
103         if (isImmediateFlush || isEndOfBatch.get() == Boolean.TRUE) {
104             flush();
105         }
106     }
107 
108     @Override
109     public synchronized void flush() {
110         buffer.flip();
111         try {
112             randomAccessFile.write(buffer.array(), 0, buffer.limit());
113         } catch (final IOException ex) {
114             final String msg = "Error writing to RandomAccessFile " + getName();
115             throw new AppenderLoggingException(msg, ex);
116         }
117         buffer.clear();
118     }
119 
120     @Override
121     public synchronized void close() {
122         flush();
123         try {
124             randomAccessFile.close();
125         } catch (final IOException ex) {
126             LOGGER.error("Unable to close RandomAccessFile " + getName() + ". "
127                     + ex);
128         }
129     }
130 
131     /**
132      * Returns the name of the File being managed.
133      *
134      * @return The name of the File being managed.
135      */
136     public String getFileName() {
137         return getName();
138     }
139 
140     /** {@code OutputStream} subclass that does not write anything. */
141     static class DummyOutputStream extends OutputStream {
142         @Override
143         public void write(final int b) throws IOException {
144         }
145 
146         @Override
147         public void write(final byte[] b, final int off, final int len) throws IOException {
148         }
149     }
150 
151     /**
152      * FileManager's content format is specified by:
153      * <p/>
154      * Key: "fileURI" Value: provided "advertiseURI" param.
155      *
156      * @return Map of content format keys supporting FileManager
157      */
158     @Override
159     public Map<String, String> getContentFormat() {
160         final Map<String, String> result = new HashMap<String, String>(
161                 super.getContentFormat());
162         result.put("fileURI", advertiseURI);
163         return result;
164     }
165 
166     /**
167      * Factory Data.
168      */
169     private static class FactoryData {
170         private final boolean append;
171         private final boolean immediateFlush;
172         private final int bufferSize;
173         private final String advertiseURI;
174         private final Layout<? extends Serializable> layout;
175 
176         /**
177          * Constructor.
178          *
179          * @param append Append status.
180          * @param bufferSize TODO
181          */
182         public FactoryData(final boolean append, final boolean immediateFlush,
183                 int bufferSize, final String advertiseURI, final Layout<? extends Serializable> layout) {
184             this.append = append;
185             this.immediateFlush = immediateFlush;
186             this.bufferSize = bufferSize;
187             this.advertiseURI = advertiseURI;
188             this.layout = layout;
189         }
190     }
191 
192     /**
193      * Factory to create a RandomAccessFileManager.
194      */
195     private static class RandomAccessFileManagerFactory implements
196             ManagerFactory<RandomAccessFileManager, FactoryData> {
197 
198         /**
199          * Create a RandomAccessFileManager.
200          *
201          * @param name The name of the File.
202          * @param data The FactoryData
203          * @return The RandomAccessFileManager for the File.
204          */
205         @Override
206         public RandomAccessFileManager createManager(final String name, final FactoryData data) {
207             final File file = new File(name);
208             final File parent = file.getParentFile();
209             if (null != parent && !parent.exists()) {
210                 parent.mkdirs();
211             }
212             if (!data.append) {
213                 file.delete();
214             }
215 
216             final OutputStream os = new DummyOutputStream();
217             RandomAccessFile raf;
218             try {
219                 raf = new RandomAccessFile(name, "rw");
220                 if (data.append) {
221                     raf.seek(raf.length());
222                 } else {
223                     raf.setLength(0);
224                 }
225                 return new RandomAccessFileManager(raf, name, os, data.immediateFlush,
226                         data.bufferSize, data.advertiseURI, data.layout);
227             } catch (final Exception ex) {
228                 LOGGER.error("RandomAccessFileManager (" + name + ") " + ex);
229             }
230             return null;
231         }
232     }
233 
234 }