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 * https://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
18 package org.apache.commons.io.channels;
19
20 import java.io.IOException;
21 import java.nio.ByteBuffer;
22 import java.nio.channels.FileChannel;
23 import java.nio.channels.ReadableByteChannel;
24
25 /**
26 * Simulates a non-blocking file channel by returning 0 from reads every other call as allowed by {@link ReadableByteChannel} and {@link FileChannel}.
27 */
28 class NonBlockingFileChannelProxy extends FileChannelProxy {
29
30 boolean toggleRead0;
31
32 NonBlockingFileChannelProxy(final FileChannel fileChannel) {
33 super(fileChannel);
34 }
35
36 private boolean flipState() {
37 return toggleRead0 = !toggleRead0;
38 }
39
40 @Override
41 public int read(final ByteBuffer dst) throws IOException {
42 return flipState() ? 0 : super.read(dst);
43 }
44
45 @Override
46 public int read(final ByteBuffer dst, final long position) throws IOException {
47 flipState();
48 return flipState() ? 0 : super.read(dst, position);
49 }
50
51 @Override
52 public long read(final ByteBuffer[] dsts, final int offset, final int length) throws IOException {
53 return flipState() ? 0 : super.read(dsts, offset, length);
54 }
55 }