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 * https://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 package org.apache.commons.compress.utils;
20
21 import java.io.IOException;
22 import java.nio.ByteBuffer;
23 import java.nio.channels.SeekableByteChannel;
24
25 /**
26 * InputStream that delegates requests to the underlying SeekableByteChannel, making sure that only bytes from a certain range can be read.
27 *
28 * @ThreadSafe
29 * @since 1.21
30 */
31 public class BoundedSeekableByteChannelInputStream extends BoundedArchiveInputStream {
32
33 private final SeekableByteChannel channel;
34
35 /**
36 * Constructs a bounded stream on the underlying {@link SeekableByteChannel}
37 *
38 * @param start Position in the stream from where the reading of this bounded stream starts
39 * @param remaining Amount of bytes which are allowed to read from the bounded stream
40 * @param channel Channel which the reads will be delegated to
41 */
42 public BoundedSeekableByteChannelInputStream(final long start, final long remaining, final SeekableByteChannel channel) {
43 super(start, remaining);
44 this.channel = channel;
45 }
46
47 @Override
48 protected int read(final long pos, final ByteBuffer buf) throws IOException {
49 final int read;
50 synchronized (channel) {
51 channel.position(pos);
52 read = channel.read(buf);
53 }
54 buf.flip();
55 return read;
56 }
57 }