1 /*
2 * ====================================================================
3 * Licensed to the Apache Software Foundation (ASF) under one
4 * or more contributor license agreements. See the NOTICE file
5 * distributed with this work for additional information
6 * regarding copyright ownership. The ASF licenses this file
7 * to you under the Apache License, Version 2.0 (the
8 * "License"); you may not use this file except in compliance
9 * with the License. You may obtain a copy of the License at
10 *
11 * http://www.apache.org/licenses/LICENSE-2.0
12 *
13 * Unless required by applicable law or agreed to in writing,
14 * software distributed under the License is distributed on an
15 * "AS IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY
16 * KIND, either express or implied. See the License for the
17 * specific language governing permissions and limitations
18 * under the License.
19 * ====================================================================
20 *
21 * This software consists of voluntary contributions made by many
22 * individuals on behalf of the Apache Software Foundation. For more
23 * information on the Apache Software Foundation, please see
24 * <http://www.apache.org/>.
25 *
26 */
27
28 package org.apache.hc.core5.http.impl.io;
29
30 import java.io.IOException;
31 import java.io.InputStream;
32
33 import org.apache.hc.core5.http.StreamClosedException;
34 import org.apache.hc.core5.http.io.SessionInputBuffer;
35 import org.apache.hc.core5.util.Args;
36
37 /**
38 * Input stream that reads data without any transformation. The end of the
39 * content entity is demarcated by closing the underlying connection
40 * (EOF condition). Entities transferred using this input stream can be of
41 * unlimited length.
42 * <p>
43 * Note that this class NEVER closes the underlying stream, even when
44 * {@link #close()} gets called. Instead, the stream will be marked as
45 * closed and no further reading will be permitted.
46 *
47 * @since 4.0
48 */
49 public class IdentityInputStream extends InputStream {
50
51 private final SessionInputBuffer buffer;
52 private final InputStream inputStream;
53
54 private boolean closed;
55
56 /**
57 * Default constructor.
58 *
59 * @param buffer Session input buffer
60 * @param inputStream Input stream
61 */
62 public IdentityInputStream(final SessionInputBuffer buffer, final InputStream inputStream) {
63 super();
64 this.buffer = Args.notNull(buffer, "Session input buffer");
65 this.inputStream = Args.notNull(inputStream, "Input stream");
66 }
67
68 @Override
69 public int available() throws IOException {
70 if (this.closed) {
71 return 0;
72 }
73 final int n = this.buffer.length();
74 return n > 0 ? n : this.inputStream.available();
75 }
76
77 /**
78 * Marks this stream as closed, but does NOT close the underlying stream.
79 * @throws IOException If an I/O problem occurs.
80 */
81 @Override
82 public void close() throws IOException {
83 this.closed = true;
84 }
85
86 @Override
87 public int read() throws IOException {
88 if (this.closed) {
89 throw new StreamClosedException();
90 }
91 return this.buffer.read(this.inputStream);
92 }
93
94 @Override
95 public int read(final byte[] b, final int off, final int len) throws IOException {
96 if (this.closed) {
97 throw new StreamClosedException();
98 }
99 return this.buffer.read(b, off, len, this.inputStream);
100 }
101
102 }