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