org.eclipse.jgit.test/tst/org/eclipse/jgit/lib/RacyGitTests.java

   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 java.io.File;
  46 import java.io.FileNotFoundException;
  47 import java.io.FileOutputStream;
  48 import java.io.IOException;
  49 import java.util.TreeSet;
  50
  51 import org.eclipse.jgit.dircache.DirCacheBuilder;
  52 import org.eclipse.jgit.dircache.DirCacheEntry;
  53 import org.eclipse.jgit.treewalk.FileTreeIterator;
  54 import org.eclipse.jgit.treewalk.FileTreeIteratorWithTimeControl;
  55 import org.eclipse.jgit.treewalk.NameConflictTreeWalk;
  56
  57 public class RacyGitTests extends RepositoryTestCase {
  58         public void testIterator() throws IllegalStateException, IOException,
  59                         InterruptedException {
  60                 TreeSet<Long> modTimes = new TreeSet<Long>();
  61                 File lastFile = null;
  62                 for (int i = 0; i < 10; i++) {
  63                         lastFile = new File(db.getWorkTree(), "0." + i);
  64                         lastFile.createNewFile();
  65                         if (i == 5)
  66                                 fsTick(lastFile);
  67                 }
  68                 modTimes.add(fsTick(lastFile));
  69                 for (int i = 0; i < 10; i++) {
  70                         lastFile = new File(db.getWorkTree(), "1." + i);
  71                         lastFile.createNewFile();
  72                 }
  73                 modTimes.add(fsTick(lastFile));
  74                 for (int i = 0; i < 10; i++) {
  75                         lastFile = new File(db.getWorkTree(), "2." + i);
  76                         lastFile.createNewFile();
  77                         if (i % 4 == 0)
  78                                 fsTick(lastFile);
  79                 }
  80                 FileTreeIteratorWithTimeControl fileIt = new FileTreeIteratorWithTimeControl(
  81                                 db, modTimes);
  82                 NameConflictTreeWalk tw = new NameConflictTreeWalk(db);
  83                 tw.reset();
  84                 tw.addTree(fileIt);
  85                 tw.setRecursive(true);
  86                 FileTreeIterator t;
  87                 long t0 = 0;
  88                 for (int i = 0; i < 10; i++) {
  89                         assertTrue(tw.next());
  90                         t = tw.getTree(0, FileTreeIterator.class);
  91                         if (i == 0)
  92                                 t0 = t.getEntryLastModified();
  93                         else
  94                                 assertEquals(t0, t.getEntryLastModified());
  95                 }
  96                 long t1 = 0;
  97                 for (int i = 0; i < 10; i++) {
  98                         assertTrue(tw.next());
  99                         t = tw.getTree(0, FileTreeIterator.class);
 100                         if (i == 0) {
 101                                 t1 = t.getEntryLastModified();
 102                                 assertTrue(t1 > t0);
 103                         } else
 104                                 assertEquals(t1, t.getEntryLastModified());
 105                 }
 106                 long t2 = 0;
 107                 for (int i = 0; i < 10; i++) {
 108                         assertTrue(tw.next());
 109                         t = tw.getTree(0, FileTreeIterator.class);
 110                         if (i == 0) {
 111                                 t2 = t.getEntryLastModified();
 112                                 assertTrue(t2 > t1);
 113                         } else
 114                                 assertEquals(t2, t.getEntryLastModified());
 115                 }
 116         }
 117
 118         public void testRacyGitDetection() throws IOException,
 119                         IllegalStateException, InterruptedException {
 120                 TreeSet<Long> modTimes = new TreeSet<Long>();
 121                 File lastFile;
 122
 123                 // wait to ensure that modtimes of the file doesn't match last index
 124                 // file modtime
 125                 modTimes.add(fsTick(db.getIndexFile()));
 126
 127                 // create two files
 128                 addToWorkDir("a", "a");
 129                 lastFile = addToWorkDir("b", "b");
 130
 131                 // wait to ensure that file-modTimes and therefore index entry modTime
 132                 // doesn't match the modtime of index-file after next persistance
 133                 modTimes.add(fsTick(lastFile));
 134
 135                 // now add both files to the index. No racy git expected
 136                 addToIndex(modTimes);
 137
 138                 assertEquals(
 139                                 "[a, mode:100644, time:t0, length:1, sha1:2e65efe2a145dda7ee51d1741299f848e5bf752e]" +
 140                                 "[b, mode:100644, time:t0, length:1, sha1:63d8dbd40c23542e740659a7168a0ce3138ea748]",
 141                                 indexState(SMUDGE | MOD_TIME | LENGTH | CONTENT_ID));
 142
 143                 // Remember the last modTime of index file. All modifications times of
 144                 // further modification are translated to this value so it looks that
 145                 // files have been modified in the same time slot as the index file
 146                 modTimes.add(Long.valueOf(db.getIndexFile().lastModified()));
 147
 148                 // modify one file
 149                 addToWorkDir("a", "a2");
 150                 // now update the index the index. 'a' has to be racily clean -- because
 151                 // it's modification time is exactly the same as the previous index file
 152                 // mod time.
 153                 addToIndex(modTimes);
 154
 155                 db.readDirCache();
 156                 // although racily clean a should not be reported as being dirty
 157                 assertEquals(
 158                                 "[a, mode:100644, time:t1, smudged, length:0]" +
 159                                 "[b, mode:100644, time:t0, length:1]",
 160                                 indexState(SMUDGE|MOD_TIME|LENGTH));
 161         }
 162
 163         /**
 164          * Waits until it is guaranteed that the filesystem timer (used e.g. for
 165          * lastModified) has a value greater than the lastmodified time of the given
 166          * file. This is done by touch a file, reading the lastmodified and sleeping
 167          * attribute sleeping
 168          *
 169          * @param lastFile
 170          * @return return the last measured value of the filesystem timer which is
 171          *         greater than then the lastmodification time of lastfile.
 172          * @throws InterruptedException
 173          * @throws IOException
 174          */
 175         public static long fsTick(File lastFile) throws InterruptedException,
 176                         IOException {
 177                 long sleepTime = 1;
 178                 File tmp = File.createTempFile("FileTreeIteratorWithTimeControl", null);
 179                 try {
 180                         long startTime = (lastFile == null) ? tmp.lastModified() : lastFile
 181                                         .lastModified();
 182                         long actTime = tmp.lastModified();
 183                         while (actTime <= startTime) {
 184                                 Thread.sleep(sleepTime);
 185                                 sleepTime *= 5;
 186                                 tmp.setLastModified(System.currentTimeMillis());
 187                                 actTime = tmp.lastModified();
 188                         }
 189                         return actTime;
 190                 } finally {
 191                         tmp.delete();
 192                 }
 193         }
 194
 195         private void addToIndex(TreeSet<Long> modTimes)
 196                         throws FileNotFoundException, IOException {
 197                 DirCacheBuilder builder = db.lockDirCache().builder();
 198                 FileTreeIterator fIt = new FileTreeIteratorWithTimeControl(
 199                                 db, modTimes);
 200                 DirCacheEntry dce;
 201                 while (!fIt.eof()) {
 202                         dce = new DirCacheEntry(fIt.getEntryPathString());
 203                         dce.setFileMode(fIt.getEntryFileMode());
 204                         dce.setLastModified(fIt.getEntryLastModified());
 205                         dce.setLength((int) fIt.getEntryLength());
 206                         dce.setObjectId(fIt.getEntryObjectId());
 207                         builder.add(dce);
 208                         fIt.next(1);
 209                 }
 210                 builder.commit();
 211         }
 212
 213         private File addToWorkDir(String path, String content) throws IOException {
 214                 File f = new File(db.getWorkTree(), path);
 215                 FileOutputStream fos = new FileOutputStream(f);
 216                 try {
 217                         fos.write(content.getBytes(Constants.CHARACTER_ENCODING));
 218                         return f;
 219                 } finally {
 220                         fos.close();
 221                 }
 222         }
 223 }