1 /*
2 * Copyright (C) 2009-2010, Google Inc.
3 * and other copyright owners as documented in the project's IP log.
4 *
5 * This program and the accompanying materials are made available
6 * under the terms of the Eclipse Distribution License v1.0 which
7 * accompanies this distribution, is reproduced below, and is
8 * available at http://www.eclipse.org/org/documents/edl-v10.php
9 *
10 * All rights reserved.
11 *
12 * Redistribution and use in source and binary forms, with or
13 * without modification, are permitted provided that the following
14 * conditions are met:
15 *
16 * - Redistributions of source code must retain the above copyright
17 * notice, this list of conditions and the following disclaimer.
18 *
19 * - Redistributions in binary form must reproduce the above
20 * copyright notice, this list of conditions and the following
21 * disclaimer in the documentation and/or other materials provided
22 * with the distribution.
23 *
24 * - Neither the name of the Eclipse Foundation, Inc. nor the
25 * names of its contributors may be used to endorse or promote
26 * products derived from this software without specific prior
27 * written permission.
28 *
29 * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
30 * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES,
31 * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES
32 * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE
33 * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR
34 * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
35 * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT
36 * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES;
37 * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER
38 * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT,
39 * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE)
40 * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF
41 * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
42 */
43
44 package org.eclipse.jgit.util.io;
45
46 import java.io.IOException;
47 import java.io.InputStream;
48 import java.io.InterruptedIOException;
49 import java.io.OutputStream;
50
51 /** Thread to copy from an input stream to an output stream. */
52 public class StreamCopyThread extends Thread {
53 private static final int BUFFER_SIZE = 1024;
54
55 private final InputStream src;
56
57 private final OutputStream dst;
58
59 private volatile boolean done;
60
61 /**
62 * Create a thread to copy data from an input stream to an output stream.
63 *
64 * @param i
65 * stream to copy from. The thread terminates when this stream
66 * reaches EOF. The thread closes this stream before it exits.
67 * @param o
68 * stream to copy into. The destination stream is automatically
69 * closed when the thread terminates.
70 */
71 public StreamCopyThread(final InputStream i, final OutputStream o) {
72 setName(Thread.currentThread().getName() + "-StreamCopy"); //$NON-NLS-1$
73 src = i;
74 dst = o;
75 }
76
77 /**
78 * Request the thread to flush the output stream as soon as possible.
79 * <p>
80 * This is an asynchronous request to the thread. The actual flush will
81 * happen at some future point in time, when the thread wakes up to process
82 * the request.
83 */
84 public void flush() {
85 interrupt();
86 }
87
88 /**
89 * Request that the thread terminate, and wait for it.
90 * <p>
91 * This method signals to the copy thread that it should stop as soon as
92 * there is no more IO occurring.
93 *
94 * @throws InterruptedException
95 * the calling thread was interrupted.
96 */
97 public void halt() throws InterruptedException {
98 for (;;) {
99 join(250 /* milliseconds */);
100 if (isAlive()) {
101 done = true;
102 interrupt();
103 } else
104 break;
105 }
106 }
107
108 @Override
109 public void run() {
110 try {
111 final byte[] buf = new byte[BUFFER_SIZE];
112 int interruptCounter = 0;
113 for (;;) {
114 try {
115 if (interruptCounter > 0) {
116 dst.flush();
117 interruptCounter--;
118 }
119
120 if (done)
121 break;
122
123 final int n;
124 try {
125 n = src.read(buf);
126 } catch (InterruptedIOException wakey) {
127 interruptCounter++;
128 continue;
129 }
130 if (n < 0)
131 break;
132
133 boolean writeInterrupted = false;
134 for (;;) {
135 try {
136 dst.write(buf, 0, n);
137 } catch (InterruptedIOException wakey) {
138 writeInterrupted = true;
139 continue;
140 }
141
142 // set interrupt status, which will be checked
143 // when we block in src.read
144 if (writeInterrupted)
145 interrupt();
146 break;
147 }
148 } catch (IOException e) {
149 break;
150 }
151 }
152 } finally {
153 try {
154 src.close();
155 } catch (IOException e) {
156 // Ignore IO errors on close
157 }
158 try {
159 dst.close();
160 } catch (IOException e) {
161 // Ignore IO errors on close
162 }
163 }
164 }
165 }