1 /*
2 * Copyright (C) 2010, 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.lib;
44
45 import static java.nio.charset.StandardCharsets.UTF_8;
46 import static org.junit.Assert.assertEquals;
47 import static org.junit.Assert.assertFalse;
48 import static org.junit.Assert.assertTrue;
49
50 import java.io.File;
51 import java.io.FileOutputStream;
52 import java.io.IOException;
53 import java.time.Instant;
54
55 import org.eclipse.jgit.api.Git;
56 import org.eclipse.jgit.dircache.DirCache;
57 import org.eclipse.jgit.junit.RepositoryTestCase;
58 import org.eclipse.jgit.junit.time.TimeUtil;
59 import org.eclipse.jgit.treewalk.FileTreeIterator;
60 import org.eclipse.jgit.treewalk.WorkingTreeOptions;
61 import org.eclipse.jgit.util.FS;
62 import org.junit.Test;
63
64 public class RacyGitTests extends RepositoryTestCase {
65
66 @Test
67 public void testRacyGitDetection() throws Exception {
68 // Reset to force creation of index file
69 try (Git git = new Git(db)) {
70 git.reset().call();
71 }
72
73 // wait to ensure that modtimes of the file doesn't match last index
74 // file modtime
75 fsTick(db.getIndexFile());
76
77 // create two files
78 File a = writeToWorkDir("a", "a");
79 File b = writeToWorkDir("b", "b");
80 TimeUtil.setLastModifiedOf(a.toPath(), b.toPath());
81 TimeUtil.setLastModifiedOf(b.toPath(), b.toPath());
82
83 // wait to ensure that file-modTimes and therefore index entry modTime
84 // doesn't match the modtime of index-file after next persistance
85 fsTick(b);
86
87 // now add both files to the index. No racy git expected
88 resetIndex(new FileTreeIterator(db));
89
90 assertEquals(
91 "[a, mode:100644, time:t0, length:1, content:a]"
92 + "[b, mode:100644, time:t0, length:1, content:b]",
93 indexState(SMUDGE | MOD_TIME | LENGTH | CONTENT));
94
95 // wait to ensure the file 'a' is updated at t1.
96 fsTick(db.getIndexFile());
97
98 // Create a racy git situation. This is a situation that the index is
99 // updated and then a file is modified within the same tick of the
100 // filesystem timestamp resolution. By changing the index file
101 // artificially, we create a fake racy situation.
102 File updatedA = writeToWorkDir("a", "a2");
103 Instant newLastModified = TimeUtil
104 .setLastModifiedWithOffset(updatedA.toPath(), 100L);
105 resetIndex(new FileTreeIterator(db));
106 FS.DETECTED.setLastModified(db.getIndexFile().toPath(),
107 newLastModified);
108
109 DirCache dc = db.readDirCache();
110 // check index state: although racily clean a should not be reported as
111 // being dirty since we forcefully reset the index to match the working
112 // tree
113 assertEquals(
114 "[a, mode:100644, time:t1, smudged, length:0, content:a2]"
115 + "[b, mode:100644, time:t0, length:1, content:b]",
116 indexState(SMUDGE | MOD_TIME | LENGTH | CONTENT));
117
118 // compare state of files in working tree with index to check that
119 // FileTreeIterator.isModified() works as expected
120 FileTreeIterator f = new FileTreeIterator(db.getWorkTree(), db.getFS(),
121 db.getConfig().get(WorkingTreeOptions.KEY));
122 assertTrue(f.findFile("a"));
123 try (ObjectReader reader = db.newObjectReader()) {
124 assertFalse(f.isModified(dc.getEntry("a"), false, reader));
125 }
126 }
127
128 private File writeToWorkDir(String path, String content) throws IOException {
129 File f = new File(db.getWorkTree(), path);
130 try (FileOutputStream fos = new FileOutputStream(f)) {
131 fos.write(content.getBytes(UTF_8));
132 return f;
133 }
134 }
135 }