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 /**
52 * Thread to copy from an input stream to an output stream.
53 */
54 public class StreamCopyThread extends Thread {
55 private static final int BUFFER_SIZE = 1024;
56
57 private final InputStream src;
58
59 private final OutputStream dst;
60
61 private volatile boolean done;
62
63 /** Lock held by flush to avoid interrupting a write. */
64 private final Object writeLock;
65
66 /**
67 * Create a thread to copy data from an input stream to an output stream.
68 *
69 * @param i
70 * stream to copy from. The thread terminates when this stream
71 * reaches EOF. The thread closes this stream before it exits.
72 * @param o
73 * stream to copy into. The destination stream is automatically
74 * closed when the thread terminates.
75 */
76 public StreamCopyThread(final InputStream i, final OutputStream o) {
77 setName(Thread.currentThread().getName() + "-StreamCopy"); //$NON-NLS-1$
78 src = i;
79 dst = o;
80 writeLock = new Object();
81 }
82
83 /**
84 * Request the thread to flush the output stream as soon as possible.
85 * <p>
86 * This is an asynchronous request to the thread. The actual flush will
87 * happen at some future point in time, when the thread wakes up to process
88 * the request.
89 */
90 @Deprecated
91 public void flush() {
92 synchronized (writeLock) {
93 interrupt();
94 }
95 }
96
97 /**
98 * Request that the thread terminate, and wait for it.
99 * <p>
100 * This method signals to the copy thread that it should stop as soon as
101 * there is no more IO occurring.
102 *
103 * @throws java.lang.InterruptedException
104 * the calling thread was interrupted.
105 */
106 public void halt() throws InterruptedException {
107 for (;;) {
108 join(250 /* milliseconds */);
109 if (isAlive()) {
110 done = true;
111 interrupt();
112 } else
113 break;
114 }
115 }
116
117 /** {@inheritDoc} */
118 @Override
119 public void run() {
120 try {
121 final byte[] buf = new byte[BUFFER_SIZE];
122 boolean readInterrupted = false;
123 for (;;) {
124 try {
125 if (readInterrupted) {
126 synchronized (writeLock) {
127 boolean interruptedAgain = Thread.interrupted();
128 dst.flush();
129 if (interruptedAgain) {
130 interrupt();
131 }
132 }
133 readInterrupted = false;
134 }
135
136 if (done)
137 break;
138
139 final int n;
140 try {
141 n = src.read(buf);
142 } catch (InterruptedIOException wakey) {
143 readInterrupted = true;
144 continue;
145 }
146 if (n < 0)
147 break;
148
149 synchronized (writeLock) {
150 boolean writeInterrupted = Thread.interrupted();
151 dst.write(buf, 0, n);
152 if (writeInterrupted) {
153 interrupt();
154 }
155 }
156 } catch (IOException e) {
157 break;
158 }
159 }
160 } finally {
161 try {
162 src.close();
163 } catch (IOException e) {
164 // Ignore IO errors on close
165 }
166 try {
167 dst.close();
168 } catch (IOException e) {
169 // Ignore IO errors on close
170 }
171 }
172 }
173 }