/*
    * Copyright (C) 2010, Christian Halstrick <christian.halstrick@sap.com>
    * and other copyright owners as documented in the project's IP log.
    *
    * 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
    *
   * 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.
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   * THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND
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  package org.eclipse.jgit.lib;
  
  import static java.lang.Long.valueOf;
  import static org.junit.Assert.assertEquals;
  import static org.junit.Assert.assertTrue;
  import static org.junit.Assume.assumeTrue;
  
  import java.io.File;
  import java.io.FileOutputStream;
  import java.io.IOException;
  import java.util.TreeSet;
  
  import org.eclipse.jgit.api.Git;
  import org.eclipse.jgit.junit.RepositoryTestCase;
  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.junit.Test;
  
  public class RacyGitTests extends RepositoryTestCase {
  	@Test
  	public void testIterator() throws IllegalStateException, IOException,
  			InterruptedException {
  		TreeSet<Long> modTimes = new TreeSet<>();
  		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);
  		try (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());
 				}
 			}
 		}
 	}
 
 	@Test
 	public void testRacyGitDetection() throws Exception {
 		TreeSet<Long> modTimes = new TreeSet<>();
 		File lastFile;
 
 		// 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())));
 
 		// create two files
 		addToWorkDir("a", "a");
 		lastFile = addToWorkDir("b", "b");
 
 		// 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)));
 
 		// now add both files to the index. No racy git expected
 		resetIndex(new FileTreeIteratorWithTimeControl(db, modTimes));
 
 		assertEquals(
 				"[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
 		long indexMod = db.getIndexFile().lastModified();
 		modTimes.add(Long.valueOf(indexMod));
 
 		// modify one file
 		long aMod = addToWorkDir("a", "a2").lastModified();
 		assumeTrue(aMod == indexMod);
 
 		// 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));
 
 		db.readDirCache();
 		// although racily clean a should not be reported as being dirty
 		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));
 	}
 
 	private File addToWorkDir(String path, String content) throws IOException {
 		File f = new File(db.getWorkTree(), path);
 		try (FileOutputStream fos = new FileOutputStream(f)) {
 			fos.write(content.getBytes(Constants.CHARACTER_ENCODING));
 			return f;
 		}
 	}
 }