diff options
Diffstat (limited to 'org.eclipse.jgit.test/tst/org/eclipse/jgit/lib/RacyGitTests.java')
| -rw-r--r-- | org.eclipse.jgit.test/tst/org/eclipse/jgit/lib/RacyGitTests.java | 209 |
1 files changed, 76 insertions, 133 deletions
diff --git a/org.eclipse.jgit.test/tst/org/eclipse/jgit/lib/RacyGitTests.java b/org.eclipse.jgit.test/tst/org/eclipse/jgit/lib/RacyGitTests.java index 99d6801f30..f25e5d10ff 100644 --- a/org.eclipse.jgit.test/tst/org/eclipse/jgit/lib/RacyGitTests.java +++ b/org.eclipse.jgit.test/tst/org/eclipse/jgit/lib/RacyGitTests.java @@ -1,175 +1,118 @@ /* - * Copyright (C) 2010, Christian Halstrick <christian.halstrick@sap.com> - * and other copyright owners as documented in the project's IP log. + * Copyright (C) 2010, Christian Halstrick <christian.halstrick@sap.com> and others * - * This program and the accompanying materials are made available - * under the terms of the Eclipse Distribution License v1.0 which - * accompanies this distribution, is reproduced below, and is - * available at http://www.eclipse.org/org/documents/edl-v10.php + * This program and the accompanying materials are made available under the + * terms of the Eclipse Distribution License v. 1.0 which is available at + * https://www.eclipse.org/org/documents/edl-v10.php. * - * All rights reserved. - * - * Redistribution and use in source and binary forms, with or - * without modification, are permitted provided that the following - * conditions are met: - * - * - Redistributions of source code must retain the above copyright - * notice, this list of conditions and the following disclaimer. - * - * - Redistributions in binary form must reproduce the above - * copyright notice, this list of conditions and the following - * disclaimer in the documentation and/or other materials provided - * with the distribution. - * - * - Neither the name of the Eclipse Foundation, Inc. nor the - * names of its contributors may be used to endorse or promote - * products derived from this software without specific prior - * written permission. - * - * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND - * CONTRIBUTORS "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, - * INCLUDING, BUT NOT LIMITED TO, THE IMPLIED WARRANTIES - * OF MERCHANTABILITY AND FITNESS FOR A PARTICULAR PURPOSE - * ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT OWNER OR - * CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL, - * SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT - * NOT LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; - * LOSS OF USE, DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER - * CAUSED AND ON ANY THEORY OF LIABILITY, WHETHER IN CONTRACT, - * STRICT LIABILITY, OR TORT (INCLUDING NEGLIGENCE OR OTHERWISE) - * ARISING IN ANY WAY OUT OF THE USE OF THIS SOFTWARE, EVEN IF - * ADVISED OF THE POSSIBILITY OF SUCH DAMAGE. + * SPDX-License-Identifier: BSD-3-Clause */ package org.eclipse.jgit.lib; -import static java.lang.Long.valueOf; +import static java.nio.charset.StandardCharsets.UTF_8; import static org.junit.Assert.assertEquals; +import static org.junit.Assert.assertFalse; import static org.junit.Assert.assertTrue; import java.io.File; import java.io.FileOutputStream; import java.io.IOException; -import java.util.TreeSet; +import java.time.Instant; +import org.eclipse.jgit.api.Git; +import org.eclipse.jgit.dircache.DirCache; import org.eclipse.jgit.junit.RepositoryTestCase; +import org.eclipse.jgit.junit.time.TimeUtil; import org.eclipse.jgit.treewalk.FileTreeIterator; -import org.eclipse.jgit.treewalk.FileTreeIteratorWithTimeControl; -import org.eclipse.jgit.treewalk.NameConflictTreeWalk; -import org.eclipse.jgit.util.FileUtils; +import org.eclipse.jgit.treewalk.WorkingTreeOptions; +import org.eclipse.jgit.util.FS; +import org.junit.Test; public class RacyGitTests extends RepositoryTestCase { - public void testIterator() throws IllegalStateException, IOException, - InterruptedException { - TreeSet<Long> modTimes = new TreeSet<Long>(); - File lastFile = null; - for (int i = 0; i < 10; i++) { - lastFile = new File(db.getWorkTree(), "0." + i); - FileUtils.createNewFile(lastFile); - if (i == 5) - fsTick(lastFile); - } - modTimes.add(valueOf(fsTick(lastFile))); - for (int i = 0; i < 10; i++) { - lastFile = new File(db.getWorkTree(), "1." + i); - FileUtils.createNewFile(lastFile); - } - modTimes.add(valueOf(fsTick(lastFile))); - for (int i = 0; i < 10; i++) { - lastFile = new File(db.getWorkTree(), "2." + i); - FileUtils.createNewFile(lastFile); - if (i % 4 == 0) - fsTick(lastFile); - } - FileTreeIteratorWithTimeControl fileIt = new FileTreeIteratorWithTimeControl( - db, modTimes); - NameConflictTreeWalk tw = new NameConflictTreeWalk(db); - tw.addTree(fileIt); - tw.setRecursive(true); - FileTreeIterator t; - long t0 = 0; - for (int i = 0; i < 10; i++) { - assertTrue(tw.next()); - t = tw.getTree(0, FileTreeIterator.class); - if (i == 0) - t0 = t.getEntryLastModified(); - else - assertEquals(t0, t.getEntryLastModified()); - } - long t1 = 0; - for (int i = 0; i < 10; i++) { - assertTrue(tw.next()); - t = tw.getTree(0, FileTreeIterator.class); - if (i == 0) { - t1 = t.getEntryLastModified(); - assertTrue(t1 > t0); - } else - assertEquals(t1, t.getEntryLastModified()); - } - long t2 = 0; - for (int i = 0; i < 10; i++) { - assertTrue(tw.next()); - t = tw.getTree(0, FileTreeIterator.class); - if (i == 0) { - t2 = t.getEntryLastModified(); - assertTrue(t2 > t1); - } else - assertEquals(t2, t.getEntryLastModified()); - } - } - public void testRacyGitDetection() throws IOException, - IllegalStateException, InterruptedException { - TreeSet<Long> modTimes = new TreeSet<Long>(); - File lastFile; + /** + * This test is inherently flaky in nature since using clocks in a computer + * to determine file modifications in a filesystem from Java is difficult + * and depends on many factors and we can't test all combinations + * + * If this test fails on your computer, don't worry but let us know if you + * are willing to provide details which may help to further improve handling + * of the racy git problem in JGit. + * + * Despite not being completely reproducible this test is still useful to + * detect regressions when running this test repeatedly on the same + * OS/filesystem/Java version (which we do on the CI used to build JGit). + * + * @see "https://git-scm.com/docs/racy-git" + * @see "https://www.youtube.com/watch?v=m44cAozuLNI" + */ + @Test + public void testRacyGitDetection() throws Exception { + // Reset to force creation of index file + try (Git git = new Git(db)) { + git.reset().call(); + } // wait to ensure that modtimes of the file doesn't match last index // file modtime - modTimes.add(valueOf(fsTick(db.getIndexFile()))); + fsTick(db.getIndexFile()); // create two files - addToWorkDir("a", "a"); - lastFile = addToWorkDir("b", "b"); + File a = writeToWorkDir("a", "a"); + File b = writeToWorkDir("b", "b"); + TimeUtil.setLastModifiedOf(a.toPath(), b.toPath()); + TimeUtil.setLastModifiedOf(b.toPath(), b.toPath()); // wait to ensure that file-modTimes and therefore index entry modTime // doesn't match the modtime of index-file after next persistance - modTimes.add(valueOf(fsTick(lastFile))); + fsTick(b); // now add both files to the index. No racy git expected - resetIndex(new FileTreeIteratorWithTimeControl(db, modTimes)); + resetIndex(new FileTreeIterator(db)); assertEquals( - "[a, mode:100644, time:t0, length:1, content:a]" + - "[b, mode:100644, time:t0, length:1, content:b]", + "[a, mode:100644, time:t0, length:1, content:a]" + + "[b, mode:100644, time:t0, length:1, content:b]", indexState(SMUDGE | MOD_TIME | LENGTH | CONTENT)); - // Remember the last modTime of index file. All modifications times of - // further modification are translated to this value so it looks that - // files have been modified in the same time slot as the index file - modTimes.add(Long.valueOf(db.getIndexFile().lastModified())); + // wait to ensure the file 'a' is updated at t1. + fsTick(db.getIndexFile()); - // modify one file - addToWorkDir("a", "a2"); - // now update the index the index. 'a' has to be racily clean -- because - // it's modification time is exactly the same as the previous index file - // mod time. - resetIndex(new FileTreeIteratorWithTimeControl(db, modTimes)); + // Create a racy git situation. This is a situation that the index is + // updated and then a file is modified within the same tick of the + // filesystem timestamp resolution. By changing the index file + // artificially, we create a fake racy situation. + File updatedA = writeToWorkDir("a", "a2"); + Instant newLastModified = TimeUtil + .setLastModifiedWithOffset(updatedA.toPath(), 100L); + resetIndex(new FileTreeIterator(db)); + FS.DETECTED.setLastModified(db.getIndexFile().toPath(), + newLastModified); - db.readDirCache(); - // although racily clean a should not be reported as being dirty + DirCache dc = db.readDirCache(); + // check index state: although racily clean a should not be reported as + // being dirty since we forcefully reset the index to match the working + // tree assertEquals( - "[a, mode:100644, time:t1, smudged, length:0, content:a2]" + - "[b, mode:100644, time:t0, length:1, content:b]", - indexState(SMUDGE|MOD_TIME|LENGTH|CONTENT)); + "[a, mode:100644, time:t1, smudged, length:0, content:a2]" + + "[b, mode:100644, time:t0, length:1, content:b]", + indexState(SMUDGE | MOD_TIME | LENGTH | CONTENT)); + + // compare state of files in working tree with index to check that + // FileTreeIterator.isModified() works as expected + FileTreeIterator f = new FileTreeIterator(db.getWorkTree(), db.getFS(), + db.getConfig().get(WorkingTreeOptions.KEY)); + assertTrue(f.findFile("a")); + try (ObjectReader reader = db.newObjectReader()) { + assertFalse(f.isModified(dc.getEntry("a"), false, reader)); + } } - private File addToWorkDir(String path, String content) throws IOException { + private File writeToWorkDir(String path, String content) throws IOException { File f = new File(db.getWorkTree(), path); - FileOutputStream fos = new FileOutputStream(f); - try { - fos.write(content.getBytes(Constants.CHARACTER_ENCODING)); + try (FileOutputStream fos = new FileOutputStream(f)) { + fos.write(content.getBytes(UTF_8)); return f; - } finally { - fos.close(); } } } |