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1   /*
2    * Copyright (C) 2016, Christian Halstrick <christian.halstrick@sap.com>
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  package org.eclipse.jgit.lfs;
44  
45  import java.io.IOException;
46  import java.io.InputStream;
47  import java.io.OutputStream;
48  import java.nio.file.Files;
49  import java.nio.file.Path;
50  import java.nio.file.StandardCopyOption;
51  
52  import org.eclipse.jgit.attributes.FilterCommand;
53  import org.eclipse.jgit.attributes.FilterCommandFactory;
54  import org.eclipse.jgit.attributes.FilterCommandRegistry;
55  import org.eclipse.jgit.lfs.errors.CorruptMediaFile;
56  import org.eclipse.jgit.lfs.internal.AtomicObjectOutputStream;
57  import org.eclipse.jgit.lfs.lib.AnyLongObjectId;
58  import org.eclipse.jgit.lfs.lib.Constants;
59  import org.eclipse.jgit.lib.Repository;
60  import org.eclipse.jgit.util.FileUtils;
61  
62  /**
63   * Built-in LFS clean filter
64   *
65   * When new content is about to be added to the git repository and this filter
66   * is configured for that content, then this filter will replace the original
67   * content with content of a so-called LFS pointer file. The pointer file
68   * content will then be added to the git repository. Additionally this filter
69   * writes the original content in a so-called 'media file' to '.git/lfs/objects/
70   * &lt;first-two-characters-of-contentid&gt;/&lt;rest-of-contentid&gt;'
71   *
72   * @see <a href="https://github.com/github/git-lfs/blob/master/docs/spec.md">Git
73   *      LFS Specification</a>
74   * @since 4.6
75   */
76  public class CleanFilter extends FilterCommand {
77  	/**
78  	 * The factory is responsible for creating instances of
79  	 * {@link org.eclipse.jgit.lfs.CleanFilter}
80  	 */
81  	public final static FilterCommandFactory FACTORY = new FilterCommandFactory() {
82  
83  		@Override
84  		public FilterCommand create(Repository db, InputStream in,
85  				OutputStream out) throws IOException {
86  			return new CleanFilter(db, in, out);
87  		}
88  	};
89  
90  	/**
91  	 * Registers this filter by calling
92  	 * {@link FilterCommandRegistry#register(String, FilterCommandFactory)}
93  	 */
94  	static void register() {
95  		FilterCommandRegistry
96  				.register(org.eclipse.jgit.lib.Constants.BUILTIN_FILTER_PREFIX
97  						+ Constants.ATTR_FILTER_DRIVER_PREFIX
98  						+ org.eclipse.jgit.lib.Constants.ATTR_FILTER_TYPE_CLEAN,
99  						FACTORY);
100 	}
101 
102 	// Used to compute the hash for the original content
103 	private AtomicObjectOutputStream aOut;
104 
105 	private Lfs lfsUtil;
106 
107 	// the size of the original content
108 	private long size;
109 
110 	// a temporary file into which the original content is written. When no
111 	// errors occur this file will be renamed to the mediafile
112 	private Path tmpFile;
113 
114 	/**
115 	 * Constructor for CleanFilter.
116 	 *
117 	 * @param db
118 	 *            the repository
119 	 * @param in
120 	 *            an {@link java.io.InputStream} providing the original content
121 	 * @param out
122 	 *            the {@link java.io.OutputStream} into which the content of the
123 	 *            pointer file should be written. That's the content which will
124 	 *            be added to the git repository
125 	 * @throws java.io.IOException
126 	 *             when the creation of the temporary file fails or when no
127 	 *             {@link java.io.OutputStream} for this file can be created
128 	 */
129 	public CleanFilter(Repository db, InputStream in, OutputStream out)
130 			throws IOException {
131 		super(in, out);
132 		lfsUtil = new Lfs(db);
133 		Files.createDirectories(lfsUtil.getLfsTmpDir());
134 		tmpFile = lfsUtil.createTmpFile();
135 		this.aOut = new AtomicObjectOutputStream(tmpFile.toAbsolutePath());
136 	}
137 
138 	/** {@inheritDoc} */
139 	@Override
140 	public int run() throws IOException {
141 		try {
142 			byte[] buf = new byte[8192];
143 			int length = in.read(buf);
144 			if (length != -1) {
145 				aOut.write(buf, 0, length);
146 				size += length;
147 				return length;
148 			} else {
149 				aOut.close();
150 				AnyLongObjectId loid = aOut.getId();
151 				aOut = null;
152 				Path mediaFile = lfsUtil.getMediaFile(loid);
153 				if (Files.isRegularFile(mediaFile)) {
154 					long fsSize = Files.size(mediaFile);
155 					if (fsSize != size) {
156 						throw new CorruptMediaFile(mediaFile, size, fsSize);
157 					} else {
158 						FileUtils.delete(tmpFile.toFile());
159 					}
160 				} else {
161 					Path parent = mediaFile.getParent();
162 					if (parent != null) {
163 						FileUtils.mkdirs(parent.toFile(), true);
164 					}
165 					FileUtils.rename(tmpFile.toFile(), mediaFile.toFile(),
166 							StandardCopyOption.ATOMIC_MOVE);
167 				}
168 				LfsPointer lfsPointer = new LfsPointer(loid, size);
169 				lfsPointer.encode(out);
170 				in.close();
171 				out.close();
172 				return -1;
173 			}
174 		} catch (IOException e) {
175 			if (aOut != null) {
176 				aOut.abort();
177 			}
178 			in.close();
179 			out.close();
180 			throw e;
181 		}
182 	}
183 }