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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.ByteArrayOutputStream;
47  import java.io.IOException;
48  import java.io.OutputStream;
49  import java.io.OutputStreamWriter;
50  import java.io.Writer;
51  
52  import org.eclipse.jgit.lib.Constants;
53  import org.eclipse.jgit.util.RawParseUtils;
54  
55  /**
56   * Combines messages from an OutputStream (hopefully in UTF-8) and a Writer.
57   * <p>
58   * This class is primarily meant for {@code BaseConnection} in contexts where a
59   * standard error stream from a command execution, as well as messages from a
60   * side-band channel, need to be combined together into a buffer to represent
61   * the complete set of messages from a remote repository.
62   * <p>
63   * Writes made to the writer are re-encoded as UTF-8 and interleaved into the
64   * buffer that {@link #getRawStream()} also writes to.
65   * <p>
66   * {@link #toString()} returns all written data, after converting it to a String
67   * under the assumption of UTF-8 encoding.
68   * <p>
69   * Internally {@link org.eclipse.jgit.util.RawParseUtils#decode(byte[])} is used
70   * by {@code toString()} tries to work out a reasonably correct character set
71   * for the raw data.
72   */
73  public class MessageWriter extends Writer {
74  	private final ByteArrayOutputStream buf;
75  
76  	private final OutputStreamWriter enc;
77  
78  	/**
79  	 * Create an empty writer.
80  	 */
81  	public MessageWriter() {
82  		buf = new ByteArrayOutputStream();
83  		enc = new OutputStreamWriter(getRawStream(), Constants.CHARSET);
84  	}
85  
86  	/** {@inheritDoc} */
87  	@Override
88  	public void write(char[] cbuf, int off, int len) throws IOException {
89  		synchronized (buf) {
90  			enc.write(cbuf, off, len);
91  			enc.flush();
92  		}
93  	}
94  
95  	/**
96  	 * Get the underlying byte stream that character writes to this writer drop
97  	 * into.
98  	 *
99  	 * @return the underlying byte stream that character writes to this writer
100 	 *         drop into. Writes to this stream should should be in UTF-8.
101 	 */
102 	public OutputStream getRawStream() {
103 		return buf;
104 	}
105 
106 	/** {@inheritDoc} */
107 	@Override
108 	public void close() throws IOException {
109 		// Do nothing, we are buffered with no resources.
110 	}
111 
112 	/** {@inheritDoc} */
113 	@Override
114 	public void flush() throws IOException {
115 		// Do nothing, we are buffered with no resources.
116 	}
117 
118 	/** @return string version of all buffered data. */
119 	/** {@inheritDoc} */
120 	@Override
121 	public String toString() {
122 		return RawParseUtils.decode(buf.toByteArray());
123 	}
124 }