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1   /*
2    *  Licensed to the Apache Software Foundation (ASF) under one
3    *  or more contributor license agreements.  See the NOTICE file
4    *  distributed with this work for additional information
5    *  regarding copyright ownership.  The ASF licenses this file
6    *  to you under the Apache License, Version 2.0 (the
7    *  "License"); you may not use this file except in compliance
8    *  with the License.  You may obtain a copy of the License at
9    *
10   *    http://www.apache.org/licenses/LICENSE-2.0
11   *
12   *  Unless required by applicable law or agreed to in writing,
13   *  software distributed under the License is distributed on an
14   *  "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
15   *  KIND, either express or implied.  See the License for the
16   *  specific language governing permissions and limitations
17   *  under the License.
18   *
19   */
20  package org.apache.mina.core.file;
21  
22  import java.io.IOException;
23  import java.nio.channels.FileChannel;
24  
25  
26  /**
27   * TODO Add documentation
28   * 
29   * 
30   * @author <a href="http://mina.apache.org">Apache MINA Project</a>
31   */
32  public class DefaultFileRegion implements FileRegion {
33  
34      private final FileChannel channel;
35  
36      private final long originalPosition;
37      private long position;
38      private long remainingBytes;
39  
40      public DefaultFileRegion(FileChannel channel) throws IOException {
41          this(channel, 0, channel.size());
42      }
43      
44      public DefaultFileRegion(FileChannel channel, long position, long remainingBytes) {
45          if (channel == null) {
46              throw new IllegalArgumentException("channel can not be null");
47          }
48          if (position < 0) {
49              throw new IllegalArgumentException("position may not be less than 0");
50          }
51          if (remainingBytes < 0) {
52              throw new IllegalArgumentException("remainingBytes may not be less than 0");
53          }
54          this.channel = channel;
55          this.originalPosition = position;
56          this.position = position;
57          this.remainingBytes = remainingBytes;
58      }
59  
60      public long getWrittenBytes() {
61          return position - originalPosition;
62      }
63  
64      public long getRemainingBytes() {
65          return remainingBytes;
66      }
67  
68      public FileChannel getFileChannel() {
69          return channel;
70      }
71  
72      public long getPosition() {
73          return position;
74      }
75  
76      public void update(long value) {
77          position += value;
78          remainingBytes -= value;
79      }
80  
81  }