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  package org.eclipse.jgit.treewalk;
  
  import static org.junit.Assert.assertEquals;
  import static org.junit.Assert.assertFalse;
  import static org.junit.Assert.assertNotNull;
  import static org.junit.Assert.assertTrue;
  
  import java.io.File;
  import java.io.IOException;
  import java.security.MessageDigest;
  
  import org.eclipse.jgit.api.Git;
  import org.eclipse.jgit.dircache.DirCache;
  import org.eclipse.jgit.dircache.DirCacheCheckout;
  import org.eclipse.jgit.dircache.DirCacheEditor;
  import org.eclipse.jgit.dircache.DirCacheEditor.PathEdit;
  import org.eclipse.jgit.dircache.DirCacheEntry;
  import org.eclipse.jgit.dircache.DirCacheIterator;
  import org.eclipse.jgit.errors.CorruptObjectException;
  import org.eclipse.jgit.errors.IncorrectObjectTypeException;
  import org.eclipse.jgit.errors.MissingObjectException;
  import org.eclipse.jgit.junit.RepositoryTestCase;
  import org.eclipse.jgit.lib.ConfigConstants;
  import org.eclipse.jgit.lib.Constants;
  import org.eclipse.jgit.lib.FileMode;
  import org.eclipse.jgit.lib.ObjectId;
  import org.eclipse.jgit.lib.ObjectReader;
  import org.eclipse.jgit.revwalk.RevCommit;
  import org.eclipse.jgit.treewalk.WorkingTreeIterator.MetadataDiff;
  import org.eclipse.jgit.treewalk.filter.PathFilter;
  import org.eclipse.jgit.util.FileUtils;
  import org.eclipse.jgit.util.RawParseUtils;
  import org.junit.Before;
  import org.junit.Test;
  
  public class FileTreeIteratorTest extends RepositoryTestCase {
  	private final String[] paths = { "a,", "a,b", "a/b", "a0b" };
  
  	private long[] mtime;
  
  	@Before
  	public void setUp() throws Exception {
  		super.setUp();
  
  		// We build the entries backwards so that on POSIX systems we
  		// are likely to get the entries in the trash directory in the
  		// opposite order of what they should be in for the iteration.
  		// This should stress the sorting code better than doing it in
  		// the correct order.
  		//
  		mtime = new long[paths.length];
  		for (int i = paths.length - 1; i >= 0; i--) {
  			final String s = paths[i];
  			writeTrashFile(s, s);
  			mtime[i] = new File(trash, s).lastModified();
  		}
 	}
 
 	@Test
 	public void testGetEntryContentLength() throws Exception {
 		final FileTreeIterator fti = new FileTreeIterator(db);
 		fti.next(1);
 		assertEquals(3, fti.getEntryContentLength());
 		fti.back(1);
 		assertEquals(2, fti.getEntryContentLength());
 		fti.next(1);
 		assertEquals(3, fti.getEntryContentLength());
 		fti.reset();
 		assertEquals(2, fti.getEntryContentLength());
 	}
 
 	@Test
 	public void testEmptyIfRootIsFile() throws Exception {
 		final File r = new File(trash, paths[0]);
 		assertTrue(r.isFile());
 		final FileTreeIterator fti = new FileTreeIterator(r, db.getFS(),
 				db.getConfig().get(WorkingTreeOptions.KEY));
 		assertTrue(fti.first());
 		assertTrue(fti.eof());
 	}
 
 	@Test
 	public void testEmptyIfRootDoesNotExist() throws Exception {
 		final File r = new File(trash, "not-existing-file");
 		assertFalse(r.exists());
 		final FileTreeIterator fti = new FileTreeIterator(r, db.getFS(),
 				db.getConfig().get(WorkingTreeOptions.KEY));
 		assertTrue(fti.first());
 		assertTrue(fti.eof());
 	}
 
 	@Test
 	public void testEmptyIfRootIsEmpty() throws Exception {
 		final File r = new File(trash, "not-existing-file");
 		assertFalse(r.exists());
 		FileUtils.mkdir(r);
 
 		final FileTreeIterator fti = new FileTreeIterator(r, db.getFS(),
 				db.getConfig().get(WorkingTreeOptions.KEY));
 		assertTrue(fti.first());
 		assertTrue(fti.eof());
 	}
 
 	@Test
 	public void testEmptyIteratorOnEmptyDirectory() throws Exception {
 		String nonExistingFileName = "not-existing-file";
 		final File r = new File(trash, nonExistingFileName);
 		assertFalse(r.exists());
 		FileUtils.mkdir(r);
 
 		final FileTreeIterator parent = new FileTreeIterator(db);
 
 		while (!parent.getEntryPathString().equals(nonExistingFileName))
 			parent.next(1);
 
 		final FileTreeIterator childIter = new FileTreeIterator(parent, r,
 				db.getFS());
 		assertTrue(childIter.first());
 		assertTrue(childIter.eof());
 
 		String parentPath = parent.getEntryPathString();
 		assertEquals(nonExistingFileName, parentPath);
 
 		// must be "not-existing-file/", but getEntryPathString() was broken by
 		// 445363 too
 		String childPath = childIter.getEntryPathString();
 
 		// in bug 445363 the iterator wrote garbage to the parent "path" field
 		EmptyTreeIterator e = childIter.createEmptyTreeIterator();
 		assertNotNull(e);
 
 		// check if parent path is not overridden by empty iterator (bug 445363)
 		// due bug 445363 this was "/ot-existing-file" instead of
 		// "not-existing-file"
 		assertEquals(parentPath, parent.getEntryPathString());
 		assertEquals(parentPath + "/", childPath);
 		assertEquals(parentPath + "/", childIter.getEntryPathString());
 		assertEquals(childPath + "/", e.getEntryPathString());
 	}
 
 	@Test
 	public void testSimpleIterate() throws Exception {
 		final FileTreeIterator top = new FileTreeIterator(trash, db.getFS(),
 				db.getConfig().get(WorkingTreeOptions.KEY));
 
 		assertTrue(top.first());
 		assertFalse(top.eof());
 		assertEquals(FileMode.REGULAR_FILE.getBits(), top.mode);
 		assertEquals(paths[0], nameOf(top));
 		assertEquals(paths[0].length(), top.getEntryLength());
 		assertEquals(mtime[0], top.getEntryLastModified());
 
 		top.next(1);
 		assertFalse(top.first());
 		assertFalse(top.eof());
 		assertEquals(FileMode.REGULAR_FILE.getBits(), top.mode);
 		assertEquals(paths[1], nameOf(top));
 		assertEquals(paths[1].length(), top.getEntryLength());
 		assertEquals(mtime[1], top.getEntryLastModified());
 
 		top.next(1);
 		assertFalse(top.first());
 		assertFalse(top.eof());
 		assertEquals(FileMode.TREE.getBits(), top.mode);
 
 		final ObjectReader reader = db.newObjectReader();
 		final AbstractTreeIterator sub = top.createSubtreeIterator(reader);
 		assertTrue(sub instanceof FileTreeIterator);
 		final FileTreeIterator subfti = (FileTreeIterator) sub;
 		assertTrue(sub.first());
 		assertFalse(sub.eof());
 		assertEquals(paths[2], nameOf(sub));
 		assertEquals(paths[2].length(), subfti.getEntryLength());
 		assertEquals(mtime[2], subfti.getEntryLastModified());
 
 		sub.next(1);
 		assertTrue(sub.eof());
 
 		top.next(1);
 		assertFalse(top.first());
 		assertFalse(top.eof());
 		assertEquals(FileMode.REGULAR_FILE.getBits(), top.mode);
 		assertEquals(paths[3], nameOf(top));
 		assertEquals(paths[3].length(), top.getEntryLength());
 		assertEquals(mtime[3], top.getEntryLastModified());
 
 		top.next(1);
 		assertTrue(top.eof());
 	}
 
 	@Test
 	public void testComputeFileObjectId() throws Exception {
 		final FileTreeIterator top = new FileTreeIterator(trash, db.getFS(),
 				db.getConfig().get(WorkingTreeOptions.KEY));
 
 		final MessageDigest md = Constants.newMessageDigest();
 		md.update(Constants.encodeASCII(Constants.TYPE_BLOB));
 		md.update((byte) ' ');
 		md.update(Constants.encodeASCII(paths[0].length()));
 		md.update((byte) 0);
 		md.update(Constants.encode(paths[0]));
 		final ObjectId expect = ObjectId.fromRaw(md.digest());
 
 		assertEquals(expect, top.getEntryObjectId());
 
 		// Verify it was cached by removing the file and getting it again.
 		//
 		FileUtils.delete(new File(trash, paths[0]));
 		assertEquals(expect, top.getEntryObjectId());
 	}
 
 	@Test
 	public void testDirCacheMatchingId() throws Exception {
 		File f = writeTrashFile("file", "content");
 		Git git = new Git(db);
 		writeTrashFile("file", "content");
 		fsTick(f);
 		git.add().addFilepattern("file").call();
 		DirCacheEntry dce = db.readDirCache().getEntry("file");
 		TreeWalk tw = new TreeWalk(db);
 		FileTreeIterator fti = new FileTreeIterator(trash, db.getFS(), db
 				.getConfig().get(WorkingTreeOptions.KEY));
 		tw.addTree(fti);
 		DirCacheIterator dci = new DirCacheIterator(db.readDirCache());
 		tw.addTree(dci);
 		fti.setDirCacheIterator(tw, 1);
 		while (tw.next() && !tw.getPathString().equals("file")) {
 			//
 		}
 		assertEquals(MetadataDiff.EQUAL, fti.compareMetadata(dce));
 		ObjectId fromRaw = ObjectId.fromRaw(fti.idBuffer(), fti.idOffset());
 		assertEquals("6b584e8ece562ebffc15d38808cd6b98fc3d97ea",
 				fromRaw.getName());
 		try (ObjectReader objectReader = db.newObjectReader()) {
 			assertFalse(fti.isModified(dce, false, objectReader));
 		}
 	}
 
 	@Test
 	public void testIsModifiedSymlinkAsFile() throws Exception {
 		writeTrashFile("symlink", "content");
 		Git git = new Git(db);
 		db.getConfig().setString(ConfigConstants.CONFIG_CORE_SECTION, null,
 				ConfigConstants.CONFIG_KEY_SYMLINKS, "false");
 		git.add().addFilepattern("symlink").call();
 		git.commit().setMessage("commit").call();
 
 		// Modify previously committed DirCacheEntry and write it back to disk
 		DirCacheEntry dce = db.readDirCache().getEntry("symlink");
 		dce.setFileMode(FileMode.SYMLINK);
 		try (ObjectReader objectReader = db.newObjectReader()) {
 			DirCacheCheckout.checkoutEntry(db, dce, objectReader);
 
 			FileTreeIterator fti = new FileTreeIterator(trash, db.getFS(),
 					db.getConfig().get(WorkingTreeOptions.KEY));
 			while (!fti.getEntryPathString().equals("symlink"))
 				fti.next(1);
 			assertFalse(fti.isModified(dce, false, objectReader));
 		}
 	}
 
 	@Test
 	public void testIsModifiedFileSmudged() throws Exception {
 		File f = writeTrashFile("file", "content");
 		Git git = new Git(db);
 		// The idea of this test is to check the smudged handling
 		// Hopefully fsTick will make sure our entry gets smudged
 		fsTick(f);
 		writeTrashFile("file", "content");
 		long lastModified = f.lastModified();
 		git.add().addFilepattern("file").call();
 		writeTrashFile("file", "conten2");
 		f.setLastModified(lastModified);
 		// We cannot trust this to go fast enough on
 		// a system with less than one-second lastModified
 		// resolution, so we force the index to have the
 		// same timestamp as the file we look at.
 		db.getIndexFile().setLastModified(lastModified);
 		DirCacheEntry dce = db.readDirCache().getEntry("file");
 		FileTreeIterator fti = new FileTreeIterator(trash, db.getFS(), db
 				.getConfig().get(WorkingTreeOptions.KEY));
 		while (!fti.getEntryPathString().equals("file"))
 			fti.next(1);
 		// If the rounding trick does not work we could skip the compareMetaData
 		// test and hope that we are usually testing the intended code path.
 		assertEquals(MetadataDiff.SMUDGED, fti.compareMetadata(dce));
 		try (ObjectReader objectReader = db.newObjectReader()) {
 			assertTrue(fti.isModified(dce, false, objectReader));
 		}
 	}
 
 	@Test
 	public void submoduleHeadMatchesIndex() throws Exception {
 		Git git = new Git(db);
 		writeTrashFile("file.txt", "content");
 		git.add().addFilepattern("file.txt").call();
 		final RevCommit id = git.commit().setMessage("create file").call();
 		final String path = "sub";
 		DirCache cache = db.lockDirCache();
 		DirCacheEditor editor = cache.editor();
 		editor.add(new PathEdit(path) {
 
 			public void apply(DirCacheEntry ent) {
 				ent.setFileMode(FileMode.GITLINK);
 				ent.setObjectId(id);
 			}
 		});
 		editor.commit();
 
 		Git.cloneRepository().setURI(db.getDirectory().toURI().toString())
 				.setDirectory(new File(db.getWorkTree(), path)).call()
 				.getRepository().close();
 
 		TreeWalk walk = new TreeWalk(db);
 		DirCacheIterator indexIter = new DirCacheIterator(db.readDirCache());
 		FileTreeIterator workTreeIter = new FileTreeIterator(db);
 		walk.addTree(indexIter);
 		walk.addTree(workTreeIter);
 		walk.setFilter(PathFilter.create(path));
 
 		assertTrue(walk.next());
 		assertTrue(indexIter.idEqual(workTreeIter));
 	}
 
 	@Test
 	public void submoduleWithNoGitDirectory() throws Exception {
 		Git git = new Git(db);
 		writeTrashFile("file.txt", "content");
 		git.add().addFilepattern("file.txt").call();
 		final RevCommit id = git.commit().setMessage("create file").call();
 		final String path = "sub";
 		DirCache cache = db.lockDirCache();
 		DirCacheEditor editor = cache.editor();
 		editor.add(new PathEdit(path) {
 
 			public void apply(DirCacheEntry ent) {
 				ent.setFileMode(FileMode.GITLINK);
 				ent.setObjectId(id);
 			}
 		});
 		editor.commit();
 
 		File submoduleRoot = new File(db.getWorkTree(), path);
 		assertTrue(submoduleRoot.mkdir());
 		assertTrue(new File(submoduleRoot, Constants.DOT_GIT).mkdir());
 
 		TreeWalk walk = new TreeWalk(db);
 		DirCacheIterator indexIter = new DirCacheIterator(db.readDirCache());
 		FileTreeIterator workTreeIter = new FileTreeIterator(db);
 		walk.addTree(indexIter);
 		walk.addTree(workTreeIter);
 		walk.setFilter(PathFilter.create(path));
 
 		assertTrue(walk.next());
 		assertFalse(indexIter.idEqual(workTreeIter));
 		assertEquals(ObjectId.zeroId(), workTreeIter.getEntryObjectId());
 	}
 
 	@Test
 	public void submoduleWithNoHead() throws Exception {
 		Git git = new Git(db);
 		writeTrashFile("file.txt", "content");
 		git.add().addFilepattern("file.txt").call();
 		final RevCommit id = git.commit().setMessage("create file").call();
 		final String path = "sub";
 		DirCache cache = db.lockDirCache();
 		DirCacheEditor editor = cache.editor();
 		editor.add(new PathEdit(path) {
 
 			public void apply(DirCacheEntry ent) {
 				ent.setFileMode(FileMode.GITLINK);
 				ent.setObjectId(id);
 			}
 		});
 		editor.commit();
 
 		assertNotNull(Git.init().setDirectory(new File(db.getWorkTree(), path))
 				.call().getRepository());
 
 		TreeWalk walk = new TreeWalk(db);
 		DirCacheIterator indexIter = new DirCacheIterator(db.readDirCache());
 		FileTreeIterator workTreeIter = new FileTreeIterator(db);
 		walk.addTree(indexIter);
 		walk.addTree(workTreeIter);
 		walk.setFilter(PathFilter.create(path));
 
 		assertTrue(walk.next());
 		assertFalse(indexIter.idEqual(workTreeIter));
 		assertEquals(ObjectId.zeroId(), workTreeIter.getEntryObjectId());
 	}
 
 	@Test
 	public void submoduleDirectoryIterator() throws Exception {
 		Git git = new Git(db);
 		writeTrashFile("file.txt", "content");
 		git.add().addFilepattern("file.txt").call();
 		final RevCommit id = git.commit().setMessage("create file").call();
 		final String path = "sub";
 		DirCache cache = db.lockDirCache();
 		DirCacheEditor editor = cache.editor();
 		editor.add(new PathEdit(path) {
 
 			public void apply(DirCacheEntry ent) {
 				ent.setFileMode(FileMode.GITLINK);
 				ent.setObjectId(id);
 			}
 		});
 		editor.commit();
 
 		Git.cloneRepository().setURI(db.getDirectory().toURI().toString())
 				.setDirectory(new File(db.getWorkTree(), path)).call()
 				.getRepository().close();
 
 		TreeWalk walk = new TreeWalk(db);
 		DirCacheIterator indexIter = new DirCacheIterator(db.readDirCache());
 		FileTreeIterator workTreeIter = new FileTreeIterator(db.getWorkTree(),
 				db.getFS(), db.getConfig().get(WorkingTreeOptions.KEY));
 		walk.addTree(indexIter);
 		walk.addTree(workTreeIter);
 		walk.setFilter(PathFilter.create(path));
 
 		assertTrue(walk.next());
 		assertTrue(indexIter.idEqual(workTreeIter));
 	}
 
 	@Test
 	public void submoduleNestedWithHeadMatchingIndex() throws Exception {
 		Git git = new Git(db);
 		writeTrashFile("file.txt", "content");
 		git.add().addFilepattern("file.txt").call();
 		final RevCommit id = git.commit().setMessage("create file").call();
 		final String path = "sub/dir1/dir2";
 		DirCache cache = db.lockDirCache();
 		DirCacheEditor editor = cache.editor();
 		editor.add(new PathEdit(path) {
 
 			public void apply(DirCacheEntry ent) {
 				ent.setFileMode(FileMode.GITLINK);
 				ent.setObjectId(id);
 			}
 		});
 		editor.commit();
 
 		Git.cloneRepository().setURI(db.getDirectory().toURI().toString())
 				.setDirectory(new File(db.getWorkTree(), path)).call()
 				.getRepository().close();
 
 		TreeWalk walk = new TreeWalk(db);
 		DirCacheIterator indexIter = new DirCacheIterator(db.readDirCache());
 		FileTreeIterator workTreeIter = new FileTreeIterator(db);
 		walk.addTree(indexIter);
 		walk.addTree(workTreeIter);
 		walk.setFilter(PathFilter.create(path));
 
 		assertTrue(walk.next());
 		assertTrue(indexIter.idEqual(workTreeIter));
 	}
 
 	@Test
 	public void idOffset() throws Exception {
 		Git git = new Git(db);
 		writeTrashFile("fileAinfsonly", "A");
 		File fileBinindex = writeTrashFile("fileBinindex", "B");
 		fsTick(fileBinindex);
 		git.add().addFilepattern("fileBinindex").call();
 		writeTrashFile("fileCinfsonly", "C");
 		TreeWalk tw = new TreeWalk(db);
 		DirCacheIterator indexIter = new DirCacheIterator(db.readDirCache());
 		FileTreeIterator workTreeIter = new FileTreeIterator(db);
 		tw.addTree(indexIter);
 		tw.addTree(workTreeIter);
 		workTreeIter.setDirCacheIterator(tw, 0);
 		assertEntry("d46c305e85b630558ee19cc47e73d2e5c8c64cdc", "a,", tw);
 		assertEntry("58ee403f98538ec02409538b3f80adf610accdec", "a,b", tw);
 		assertEntry("0000000000000000000000000000000000000000", "a", tw);
 		assertEntry("b8d30ff397626f0f1d3538d66067edf865e201d6", "a0b", tw);
 		// The reason for adding this test. Check that the id is correct for
 		// mixed
 		assertEntry("8c7e5a667f1b771847fe88c01c3de34413a1b220",
 				"fileAinfsonly", tw);
 		assertEntry("7371f47a6f8bd23a8fa1a8b2a9479cdd76380e54", "fileBinindex",
 				tw);
 		assertEntry("96d80cd6c4e7158dbebd0849f4fb7ce513e5828c",
 				"fileCinfsonly", tw);
 		assertFalse(tw.next());
 	}
 
 	private static void assertEntry(String sha1string, String path, TreeWalk tw)
 			throws MissingObjectException, IncorrectObjectTypeException,
 			CorruptObjectException, IOException {
 		assertTrue(tw.next());
 		assertEquals(path, tw.getPathString());
 		assertEquals(sha1string, tw.getObjectId(1).getName() /* 1=filetree here */);
 	}
 
 	private static String nameOf(final AbstractTreeIterator i) {
 		return RawParseUtils.decode(Constants.CHARSET, i.path, 0, i.pathLen);
 	}
 }