View Javadoc
1   /*
2    * Copyright (C) 2017, Markus Duft <markus.duft@ssi-schaefer.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.nio.file.Files;
48  import java.nio.file.Path;
49  
50  import org.eclipse.jgit.lfs.lib.AnyLongObjectId;
51  import org.eclipse.jgit.lib.ObjectLoader;
52  import org.eclipse.jgit.lib.Repository;
53  import org.eclipse.jgit.util.TemporaryBuffer;
54  import org.eclipse.jgit.util.TemporaryBuffer.LocalFile;
55  
56  /**
57   * Provides transparently either a stream to the blob or a LFS media file if
58   * managed by LFS.
59   *
60   * @since 4.11
61   */
62  public class LfsBlobFilter {
63  
64  	/**
65  	 * In case the given {@link ObjectLoader} points to a LFS pointer file
66  	 * replace the loader with one pointing to the LFS media file contents.
67  	 * Missing LFS files are downloaded on the fly - same logic as the smudge
68  	 * filter.
69  	 *
70  	 * @param db
71  	 *            the repo
72  	 * @param loader
73  	 *            the loader for the blob
74  	 * @return either the original loader, or a loader for the LFS media file if
75  	 *         managed by LFS. Files are downloaded on demand if required.
76  	 * @throws IOException
77  	 *             in case of an error
78  	 */
79  	public static ObjectLoader smudgeLfsBlob(Repository db, ObjectLoader loader)
80  			throws IOException {
81  		if (loader.getSize() > LfsPointer.SIZE_THRESHOLD) {
82  			return loader;
83  		}
84  
85  		try (InputStream is = loader.openStream()) {
86  			LfsPointer ptr = LfsPointer.parseLfsPointer(is);
87  			if (ptr != null) {
88  				Lfs lfs = new Lfs(db);
89  				AnyLongObjectId oid = ptr.getOid();
90  				Path mediaFile = lfs.getMediaFile(oid);
91  				if (!Files.exists(mediaFile)) {
92  					SmudgeFilter.downloadLfsResource(lfs, db, ptr);
93  				}
94  
95  				return new LfsBlobLoader(mediaFile);
96  			}
97  		}
98  
99  		return loader;
100 	}
101 
102 	/**
103 	 * Run the LFS clean filter on the given stream and return a stream to the
104 	 * LFS pointer file buffer. Used when inserting objects.
105 	 *
106 	 * @param db
107 	 *            the {@link Repository}
108 	 * @param originalContent
109 	 *            the {@link InputStream} to the original content
110 	 * @return a {@link TemporaryBuffer} representing the LFS pointer. The
111 	 *         caller is responsible to destroy the buffer.
112 	 * @throws IOException
113 	 *             in case of any error.
114 	 */
115 	public static TemporaryBuffer cleanLfsBlob(Repository db,
116 			InputStream originalContent) throws IOException {
117 		LocalFile buffer = new TemporaryBuffer.LocalFile(null);
118 		CleanFilter f = new CleanFilter(db, originalContent, buffer);
119 		try {
120 			while (f.run() != -1) {
121 				// loop as long as f.run() tells there is work to do
122 			}
123 		} catch (IOException e) {
124 			buffer.destroy();
125 			throw e;
126 		}
127 		return buffer;
128 	}
129 
130 }