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.nio.channels.FileChannel;
23
24 /**
25 * Indicates the region of a file to be sent to the remote host.
26 *
27 * @author <a href="http://mina.apache.org">Apache MINA Project</a>
28 */
29 public interface FileRegion {
30
31 /**
32 * The open <tt>FileChannel</tt> from which data will be read to send to
33 * remote host.
34 *
35 * @return An open <tt>FileChannel</tt>.
36 */
37 FileChannel getFileChannel();
38
39 /**
40 * The current file position from which data will be read.
41 *
42 * @return The current file position.
43 */
44 long getPosition();
45
46 /**
47 * Updates the current file position based on the specified amount. This
48 * increases the value returned by {@link #getPosition()} and
49 * {@link #getWrittenBytes()} by the given amount and decreases the value
50 * returned by {@link #getRemainingBytes()} by the given {@code amount}.
51 *
52 * @param amount
53 * The new value for the file position.
54 */
55 void update(long amount);
56
57 /**
58 * The number of bytes remaining to be written from the file to the remote
59 * host.
60 *
61 * @return The number of bytes remaining to be written.
62 */
63 long getRemainingBytes();
64
65 /**
66 * The total number of bytes already written.
67 *
68 * @return The total number of bytes already written.
69 */
70 long getWrittenBytes();
71
72 /**
73 * Provides an absolute filename for the underlying FileChannel.
74 *
75 * @return the absolute filename, or <tt>null</tt> if the FileRegion
76 * does not know the filename
77 */
78 String getFilename();
79 }
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