Java Code Examples for org.apache.hadoop.hdfs.server.namenode.INodeDirectory#getChildrenList()

/**
 * @return If there is no corresponding directory diff for the given
 *         snapshot, this means that the current children list should be
 *         returned for the snapshot. Otherwise we calculate the children list
 *         for the snapshot and return it. 
 */
public ReadOnlyList<INode> getChildrenList(INodeDirectory currentINode,
    final int snapshotId) {
  final DirectoryDiff diff = diffs.getDiffById(snapshotId);
  return diff != null ? diff.getChildrenList(currentINode) : currentINode
      .getChildrenList(Snapshot.CURRENT_STATE_ID);
}
 

/**
 * @return If there is no corresponding directory diff for the given
 *         snapshot, this means that the current children list should be
 *         returned for the snapshot. Otherwise we calculate the children list
 *         for the snapshot and return it. 
 */
public ReadOnlyList<INode> getChildrenList(INodeDirectory currentINode,
    final int snapshotId) {
  final DirectoryDiff diff = diffs.getDiffById(snapshotId);
  return diff != null ? diff.getChildrenList(currentINode) : currentINode
      .getChildrenList(Snapshot.CURRENT_STATE_ID);
}
 

/**
 * After the following operations:
 * Rename a dir -> create a snapshot s on dst tree -> rename the renamed dir
 * again -> delete snapshot s on dst tree
 * 
 * Make sure we only delete the snapshot s under the renamed dir.
 */
@Test
public void testRenameDirAndDeleteSnapshot_4() throws Exception {
  final Path sdir1 = new Path("/dir1");
  final Path sdir2 = new Path("/dir2");
  final Path foo = new Path(sdir1, "foo");
  final Path bar = new Path(foo, "bar");
  DFSTestUtil.createFile(hdfs, bar, BLOCKSIZE, REPL, SEED);
  hdfs.mkdirs(sdir2);
  
  SnapshotTestHelper.createSnapshot(hdfs, sdir1, "s1");
  SnapshotTestHelper.createSnapshot(hdfs, sdir2, "s2");
  
  final Path foo2 = new Path(sdir2, "foo");
  hdfs.rename(foo, foo2);
  
  // create two new files under foo2
  final Path bar2 = new Path(foo2, "bar2");
  DFSTestUtil.createFile(hdfs, bar2, BLOCKSIZE, REPL, SEED);
  final Path bar3 = new Path(foo2, "bar3");
  DFSTestUtil.createFile(hdfs, bar3, BLOCKSIZE, REPL, SEED);
  
  // create a new snapshot on sdir2
  hdfs.createSnapshot(sdir2, "s3");
  
  // rename foo2 again
  hdfs.rename(foo2, foo);
  // delete snapshot s3
  hdfs.deleteSnapshot(sdir2, "s3");
  
  // check
  final INodeDirectory dir1Node = fsdir.getINode4Write(sdir1.toString())
      .asDirectory();
  // sdir1 + s1 + foo_s1 (foo) + foo (foo + s1 + bar~bar3)
  QuotaCounts q1 = dir1Node.getDirectoryWithQuotaFeature().getSpaceConsumed();
  assertEquals(7, q1.getNameSpace());
  final INodeDirectory dir2Node = fsdir.getINode4Write(sdir2.toString())
      .asDirectory();
  QuotaCounts q2 = dir2Node.getDirectoryWithQuotaFeature().getSpaceConsumed();
  assertEquals(1, q2.getNameSpace());
  
  final Path foo_s1 = SnapshotTestHelper.getSnapshotPath(sdir1, "s1",
      foo.getName());
  final INode fooRef = fsdir.getINode(foo_s1.toString());
  assertTrue(fooRef instanceof INodeReference.WithName);
  INodeReference.WithCount wc = 
      (WithCount) fooRef.asReference().getReferredINode();
  assertEquals(2, wc.getReferenceCount());
  INodeDirectory fooNode = wc.getReferredINode().asDirectory();
  ReadOnlyList<INode> children = fooNode
      .getChildrenList(Snapshot.CURRENT_STATE_ID);
  assertEquals(3, children.size());
  assertEquals(bar.getName(), children.get(0).getLocalName());
  assertEquals(bar2.getName(), children.get(1).getLocalName());
  assertEquals(bar3.getName(), children.get(2).getLocalName());
  List<DirectoryDiff> diffList = fooNode.getDiffs().asList();
  assertEquals(1, diffList.size());
  Snapshot s1 = dir1Node.getSnapshot(DFSUtil.string2Bytes("s1"));
  assertEquals(s1.getId(), diffList.get(0).getSnapshotId());
  ChildrenDiff diff = diffList.get(0).getChildrenDiff();
  // bar2 and bar3 in the created list
  assertEquals(2, diff.getList(ListType.CREATED).size());
  assertEquals(0, diff.getList(ListType.DELETED).size());
  
  final INode fooRef2 = fsdir.getINode4Write(foo.toString());
  assertTrue(fooRef2 instanceof INodeReference.DstReference);
  INodeReference.WithCount wc2 = 
      (WithCount) fooRef2.asReference().getReferredINode();
  assertSame(wc, wc2);
  assertSame(fooRef2, wc.getParentReference());
  
  restartClusterAndCheckImage(true);
}
 

/**
 * Clean an inode while we move it from the deleted list of post to the
 * deleted list of prior.
 * @param bsps The block storage policy suite.
 * @param inode The inode to clean.
 * @param post The post snapshot.
 * @param prior The id of the prior snapshot.
 * @param collectedBlocks Used to collect blocks for later deletion.
 * @return Quota usage update.
 */
private static QuotaCounts cleanDeletedINode(
    final BlockStoragePolicySuite bsps, INode inode,
    final int post, final int prior,
    final BlocksMapUpdateInfo collectedBlocks,
    final List<INode> removedINodes) {
  QuotaCounts counts = new QuotaCounts.Builder().build();
  Deque<INode> queue = new ArrayDeque<INode>();
  queue.addLast(inode);
  while (!queue.isEmpty()) {
    INode topNode = queue.pollFirst();
    if (topNode instanceof INodeReference.WithName) {
      INodeReference.WithName wn = (INodeReference.WithName) topNode;
      if (wn.getLastSnapshotId() >= post) {
        INodeReference.WithCount wc =
            (INodeReference.WithCount) wn.getReferredINode();
        if (wc.getLastWithName() == wn && wc.getParentReference() == null) {
          // this wn is the last wn inside of the wc, also the dstRef node has
          // been deleted. In this case, we should treat the referred file/dir
          // as normal case
          queue.add(wc.getReferredINode());
        } else {
          wn.cleanSubtree(bsps, post, prior, collectedBlocks, removedINodes);
        }
      }
      // For DstReference node, since the node is not in the created list of
      // prior, we should treat it as regular file/dir
    } else if (topNode.isFile() && topNode.asFile().isWithSnapshot()) {
      INodeFile file = topNode.asFile();
      counts.add(file.getDiffs().deleteSnapshotDiff(bsps, post, prior, file,
          collectedBlocks, removedINodes));
    } else if (topNode.isDirectory()) {
      INodeDirectory dir = topNode.asDirectory();
      ChildrenDiff priorChildrenDiff = null;
      DirectoryWithSnapshotFeature sf = dir.getDirectoryWithSnapshotFeature();
      if (sf != null) {
        // delete files/dirs created after prior. Note that these
        // files/dirs, along with inode, were deleted right after post.
        DirectoryDiff priorDiff = sf.getDiffs().getDiffById(prior);
        if (priorDiff != null && priorDiff.getSnapshotId() == prior) {
          priorChildrenDiff = priorDiff.getChildrenDiff();
          counts.add(priorChildrenDiff.destroyCreatedList(bsps, dir,
              collectedBlocks, removedINodes));
        }
      }
      
      for (INode child : dir.getChildrenList(prior)) {
        if (priorChildrenDiff != null
            && priorChildrenDiff.search(ListType.DELETED,
                child.getLocalNameBytes()) != null) {
          continue;
        }
        queue.addLast(child);
      }
    }
  }
  return counts;
}
 

/**
 * After the following operations:
 * Rename a dir -> create a snapshot s on dst tree -> delete the renamed dir
 * -> delete snapshot s on dst tree
 * 
 * Make sure we destroy everything created after the rename under the renamed
 * dir.
 */
@Test
public void testRenameDirAndDeleteSnapshot_3() throws Exception {
  final Path sdir1 = new Path("/dir1");
  final Path sdir2 = new Path("/dir2");
  final Path foo = new Path(sdir1, "foo");
  final Path bar = new Path(foo, "bar");
  DFSTestUtil.createFile(hdfs, bar, BLOCKSIZE, REPL, SEED);
  hdfs.mkdirs(sdir2);
  
  SnapshotTestHelper.createSnapshot(hdfs, sdir1, "s1");
  SnapshotTestHelper.createSnapshot(hdfs, sdir2, "s2");
  
  final Path foo2 = new Path(sdir2, "foo");
  hdfs.rename(foo, foo2);
  
  // create two new files under foo2
  final Path bar2 = new Path(foo2, "bar2");
  DFSTestUtil.createFile(hdfs, bar2, BLOCKSIZE, REPL, SEED);
  final Path bar3 = new Path(foo2, "bar3");
  DFSTestUtil.createFile(hdfs, bar3, BLOCKSIZE, REPL, SEED);
  
  // create a new snapshot on sdir2
  hdfs.createSnapshot(sdir2, "s3");
  
  // delete foo2
  hdfs.delete(foo2, true);
  // delete s3
  hdfs.deleteSnapshot(sdir2, "s3");
  
  // check
  final INodeDirectory dir1Node = fsdir.getINode4Write(sdir1.toString())
      .asDirectory();
  QuotaCounts q1 = dir1Node.getDirectoryWithQuotaFeature().getSpaceConsumed();
  assertEquals(3, q1.getNameSpace());
  final INodeDirectory dir2Node = fsdir.getINode4Write(sdir2.toString())
      .asDirectory();
  QuotaCounts q2 = dir2Node.getDirectoryWithQuotaFeature().getSpaceConsumed();
  assertEquals(1, q2.getNameSpace());
  
  final Path foo_s1 = SnapshotTestHelper.getSnapshotPath(sdir1, "s1",
      foo.getName());
  INode fooRef = fsdir.getINode(foo_s1.toString());
  assertTrue(fooRef instanceof INodeReference.WithName);
  INodeReference.WithCount wc = 
      (WithCount) fooRef.asReference().getReferredINode();
  assertEquals(1, wc.getReferenceCount());
  INodeDirectory fooNode = wc.getReferredINode().asDirectory();
  ReadOnlyList<INode> children = fooNode
      .getChildrenList(Snapshot.CURRENT_STATE_ID);
  assertEquals(1, children.size());
  assertEquals(bar.getName(), children.get(0).getLocalName());
  List<DirectoryDiff> diffList = fooNode.getDiffs().asList();
  assertEquals(1, diffList.size());
  Snapshot s1 = dir1Node.getSnapshot(DFSUtil.string2Bytes("s1"));
  assertEquals(s1.getId(), diffList.get(0).getSnapshotId());
  ChildrenDiff diff = diffList.get(0).getChildrenDiff();
  assertEquals(0, diff.getList(ListType.CREATED).size());
  assertEquals(0, diff.getList(ListType.DELETED).size());
  
  restartClusterAndCheckImage(true);
}
 

/**
 * Test rename to an invalid name (xxx/.snapshot)
 */
@Test
public void testRenameUndo_7() throws Exception {
  final Path root = new Path("/");
  final Path foo = new Path(root, "foo");
  final Path bar = new Path(foo, "bar");
  DFSTestUtil.createFile(hdfs, bar, BLOCKSIZE, REPL, SEED);
  
  // create a snapshot on root
  SnapshotTestHelper.createSnapshot(hdfs, root, snap1);
  
  // rename bar to /foo/.snapshot which is invalid
  final Path invalid = new Path(foo, HdfsConstants.DOT_SNAPSHOT_DIR);
  try {
    hdfs.rename(bar, invalid);
    fail("expect exception since invalid name is used for rename");
  } catch (Exception e) {
    GenericTestUtils.assertExceptionContains("\"" +
        HdfsConstants.DOT_SNAPSHOT_DIR + "\" is a reserved name", e);
  }
  
  // check
  INodeDirectory rootNode = fsdir.getINode4Write(root.toString())
      .asDirectory();
  INodeDirectory fooNode = fsdir.getINode4Write(foo.toString()).asDirectory();
  ReadOnlyList<INode> children = fooNode
      .getChildrenList(Snapshot.CURRENT_STATE_ID);
  assertEquals(1, children.size());
  List<DirectoryDiff> diffList = fooNode.getDiffs().asList();
  assertEquals(1, diffList.size());
  DirectoryDiff diff = diffList.get(0);
  // this diff is generated while renaming
  Snapshot s1 = rootNode.getSnapshot(DFSUtil.string2Bytes(snap1));
  assertEquals(s1.getId(), diff.getSnapshotId());
  // after undo, the diff should be empty
  assertTrue(diff.getChildrenDiff().getList(ListType.DELETED).isEmpty());
  assertTrue(diff.getChildrenDiff().getList(ListType.CREATED).isEmpty());
  
  // bar was converted to filewithsnapshot while renaming
  INodeFile barNode = fsdir.getINode4Write(bar.toString()).asFile();
  assertSame(barNode, children.get(0));
  assertSame(fooNode, barNode.getParent());
  List<FileDiff> barDiffList = barNode.getDiffs().asList();
  assertEquals(1, barDiffList.size());
  FileDiff barDiff = barDiffList.get(0);
  assertEquals(s1.getId(), barDiff.getSnapshotId());
  
  // restart cluster multiple times to make sure the fsimage and edits log are
  // correct. Note that when loading fsimage, foo and bar will be converted 
  // back to normal INodeDirectory and INodeFile since they do not store any 
  // snapshot data
  hdfs.setSafeMode(SafeModeAction.SAFEMODE_ENTER);
  hdfs.saveNamespace();
  hdfs.setSafeMode(SafeModeAction.SAFEMODE_LEAVE);
  cluster.shutdown();
  cluster = new MiniDFSCluster.Builder(conf).format(false)
      .numDataNodes(REPL).build();
  cluster.waitActive();
  restartClusterAndCheckImage(true);
}
 

/**
 * Test the undo section of the second-time rename.
 */
@Test
public void testRenameUndo_3() throws Exception {
  final Path sdir1 = new Path("/dir1");
  final Path sdir2 = new Path("/dir2");
  final Path sdir3 = new Path("/dir3");
  hdfs.mkdirs(sdir1);
  hdfs.mkdirs(sdir2);
  hdfs.mkdirs(sdir3);
  final Path foo = new Path(sdir1, "foo");
  final Path bar = new Path(foo, "bar");
  DFSTestUtil.createFile(hdfs, bar, BLOCKSIZE, REPL, SEED);
  
  SnapshotTestHelper.createSnapshot(hdfs, sdir1, "s1");
  SnapshotTestHelper.createSnapshot(hdfs, sdir2, "s2");
  
  INodeDirectory dir3 = fsdir.getINode4Write(sdir3.toString()).asDirectory();
  INodeDirectory mockDir3 = spy(dir3);
  doReturn(false).when(mockDir3).addChild((INode) anyObject(), anyBoolean(),
          Mockito.anyInt());
  INodeDirectory root = fsdir.getINode4Write("/").asDirectory();
  root.replaceChild(dir3, mockDir3, fsdir.getINodeMap());
  
  final Path foo_dir2 = new Path(sdir2, "foo2");
  final Path foo_dir3 = new Path(sdir3, "foo3");
  hdfs.rename(foo, foo_dir2);
  boolean result = hdfs.rename(foo_dir2, foo_dir3);
  assertFalse(result);
  
  // check the current internal details
  INodeDirectory dir1Node = fsdir.getINode4Write(sdir1.toString())
      .asDirectory();
  Snapshot s1 = dir1Node.getSnapshot(DFSUtil.string2Bytes("s1"));
  INodeDirectory dir2Node = fsdir.getINode4Write(sdir2.toString())
      .asDirectory();
  Snapshot s2 = dir2Node.getSnapshot(DFSUtil.string2Bytes("s2"));
  ReadOnlyList<INode> dir2Children = dir2Node
      .getChildrenList(Snapshot.CURRENT_STATE_ID);
  assertEquals(1, dir2Children.size());
  List<DirectoryDiff> dir2Diffs = dir2Node.getDiffs().asList();
  assertEquals(1, dir2Diffs.size());
  assertEquals(s2.getId(), dir2Diffs.get(0).getSnapshotId());
  ChildrenDiff childrenDiff = dir2Diffs.get(0).getChildrenDiff();
  assertEquals(0, childrenDiff.getList(ListType.DELETED).size());
  assertEquals(1, childrenDiff.getList(ListType.CREATED).size());
  final Path foo_s2 = SnapshotTestHelper.getSnapshotPath(sdir2, "s2", "foo2");
  assertFalse(hdfs.exists(foo_s2));
  
  INode fooNode = fsdir.getINode4Write(foo_dir2.toString());
  assertTrue(childrenDiff.getList(ListType.CREATED).get(0) == fooNode);
  assertTrue(fooNode instanceof INodeReference.DstReference);
  List<DirectoryDiff> fooDiffs = fooNode.asDirectory().getDiffs().asList();
  assertEquals(1, fooDiffs.size());
  assertEquals(s1.getId(), fooDiffs.get(0).getSnapshotId());
  
  // create snapshot on sdir2 and rename again
  hdfs.createSnapshot(sdir2, "s3");
  result = hdfs.rename(foo_dir2, foo_dir3);
  assertFalse(result);

  // check internal details again
  dir2Node = fsdir.getINode4Write(sdir2.toString()).asDirectory();
  Snapshot s3 = dir2Node.getSnapshot(DFSUtil.string2Bytes("s3"));
  fooNode = fsdir.getINode4Write(foo_dir2.toString());
  dir2Children = dir2Node.getChildrenList(Snapshot.CURRENT_STATE_ID);
  assertEquals(1, dir2Children.size());
  dir2Diffs = dir2Node.getDiffs().asList();
  assertEquals(2, dir2Diffs.size());
  assertEquals(s2.getId(), dir2Diffs.get(0).getSnapshotId());
  assertEquals(s3.getId(), dir2Diffs.get(1).getSnapshotId());
  
  childrenDiff = dir2Diffs.get(0).getChildrenDiff();
  assertEquals(0, childrenDiff.getList(ListType.DELETED).size());
  assertEquals(1, childrenDiff.getList(ListType.CREATED).size());
  assertTrue(childrenDiff.getList(ListType.CREATED).get(0) == fooNode);
  
  childrenDiff = dir2Diffs.get(1).getChildrenDiff();
  assertEquals(0, childrenDiff.getList(ListType.DELETED).size());
  assertEquals(0, childrenDiff.getList(ListType.CREATED).size());
  
  final Path foo_s3 = SnapshotTestHelper.getSnapshotPath(sdir2, "s3", "foo2");
  assertFalse(hdfs.exists(foo_s2));
  assertTrue(hdfs.exists(foo_s3));
  
  assertTrue(fooNode instanceof INodeReference.DstReference);
  fooDiffs = fooNode.asDirectory().getDiffs().asList();
  assertEquals(2, fooDiffs.size());
  assertEquals(s1.getId(), fooDiffs.get(0).getSnapshotId());
  assertEquals(s3.getId(), fooDiffs.get(1).getSnapshotId());
}
 

/**
 * Test the undo section of rename. Before the rename, we create the renamed 
 * file/dir after taking the snapshot.
 */
@Test
public void testRenameUndo_2() throws Exception {
  final Path sdir1 = new Path("/dir1");
  final Path sdir2 = new Path("/dir2");
  hdfs.mkdirs(sdir1);
  hdfs.mkdirs(sdir2);
  final Path dir2file = new Path(sdir2, "file");
  DFSTestUtil.createFile(hdfs, dir2file, BLOCKSIZE, REPL, SEED);
  
  SnapshotTestHelper.createSnapshot(hdfs, sdir1, "s1");
  
  // create foo after taking snapshot
  final Path foo = new Path(sdir1, "foo");
  final Path bar = new Path(foo, "bar");
  DFSTestUtil.createFile(hdfs, bar, BLOCKSIZE, REPL, SEED);
  
  INodeDirectory dir2 = fsdir.getINode4Write(sdir2.toString()).asDirectory();
  INodeDirectory mockDir2 = spy(dir2);
  doReturn(false).when(mockDir2).addChild((INode) anyObject(), anyBoolean(),
          Mockito.anyInt());
  INodeDirectory root = fsdir.getINode4Write("/").asDirectory();
  root.replaceChild(dir2, mockDir2, fsdir.getINodeMap());
  
  final Path newfoo = new Path(sdir2, "foo");
  boolean result = hdfs.rename(foo, newfoo);
  assertFalse(result);
  
  // check the current internal details
  INodeDirectory dir1Node = fsdir.getINode4Write(sdir1.toString())
      .asDirectory();
  Snapshot s1 = dir1Node.getSnapshot(DFSUtil.string2Bytes("s1"));
  ReadOnlyList<INode> dir1Children = dir1Node
      .getChildrenList(Snapshot.CURRENT_STATE_ID);
  assertEquals(1, dir1Children.size());
  assertEquals(foo.getName(), dir1Children.get(0).getLocalName());
  List<DirectoryDiff> dir1Diffs = dir1Node.getDiffs().asList();
  assertEquals(1, dir1Diffs.size());
  assertEquals(s1.getId(), dir1Diffs.get(0).getSnapshotId());
  
  // after the undo of rename, the created list of sdir1 should contain 
  // 1 element
  ChildrenDiff childrenDiff = dir1Diffs.get(0).getChildrenDiff();
  assertEquals(0, childrenDiff.getList(ListType.DELETED).size());
  assertEquals(1, childrenDiff.getList(ListType.CREATED).size());
  
  INode fooNode = fsdir.getINode4Write(foo.toString());
  assertTrue(fooNode instanceof INodeDirectory);
  assertTrue(childrenDiff.getList(ListType.CREATED).get(0) == fooNode);
  
  final Path foo_s1 = SnapshotTestHelper.getSnapshotPath(sdir1, "s1", "foo");
  assertFalse(hdfs.exists(foo_s1));
  
  // check sdir2
  assertFalse(hdfs.exists(newfoo));
  INodeDirectory dir2Node = fsdir.getINode4Write(sdir2.toString())
      .asDirectory();
  assertFalse(dir2Node.isWithSnapshot());
  ReadOnlyList<INode> dir2Children = dir2Node
      .getChildrenList(Snapshot.CURRENT_STATE_ID);
  assertEquals(1, dir2Children.size());
  assertEquals(dir2file.getName(), dir2Children.get(0).getLocalName());
}
 

/**
 * Test the undo section of rename. Before the rename, we create the renamed 
 * file/dir before taking the snapshot.
 */
@Test
public void testRenameUndo_1() throws Exception {
  final Path sdir1 = new Path("/dir1");
  final Path sdir2 = new Path("/dir2");
  hdfs.mkdirs(sdir1);
  hdfs.mkdirs(sdir2);
  final Path foo = new Path(sdir1, "foo");
  final Path bar = new Path(foo, "bar");
  DFSTestUtil.createFile(hdfs, bar, BLOCKSIZE, REPL, SEED);
  final Path dir2file = new Path(sdir2, "file");
  DFSTestUtil.createFile(hdfs, dir2file, BLOCKSIZE, REPL, SEED);
  
  SnapshotTestHelper.createSnapshot(hdfs, sdir1, "s1");
  
  INodeDirectory dir2 = fsdir.getINode4Write(sdir2.toString()).asDirectory();
  INodeDirectory mockDir2 = spy(dir2);
  doReturn(false).when(mockDir2).addChild((INode) anyObject(), anyBoolean(),
         Mockito.anyInt());
  INodeDirectory root = fsdir.getINode4Write("/").asDirectory();
  root.replaceChild(dir2, mockDir2, fsdir.getINodeMap());
  
  final Path newfoo = new Path(sdir2, "foo");
  boolean result = hdfs.rename(foo, newfoo);
  assertFalse(result);
  
  // check the current internal details
  INodeDirectory dir1Node = fsdir.getINode4Write(sdir1.toString())
      .asDirectory();
  Snapshot s1 = dir1Node.getSnapshot(DFSUtil.string2Bytes("s1"));
  ReadOnlyList<INode> dir1Children = dir1Node
      .getChildrenList(Snapshot.CURRENT_STATE_ID);
  assertEquals(1, dir1Children.size());
  assertEquals(foo.getName(), dir1Children.get(0).getLocalName());
  List<DirectoryDiff> dir1Diffs = dir1Node.getDiffs().asList();
  assertEquals(1, dir1Diffs.size());
  assertEquals(s1.getId(), dir1Diffs.get(0).getSnapshotId());
  
  // after the undo of rename, both the created and deleted list of sdir1
  // should be empty
  ChildrenDiff childrenDiff = dir1Diffs.get(0).getChildrenDiff();
  assertEquals(0, childrenDiff.getList(ListType.DELETED).size());
  assertEquals(0, childrenDiff.getList(ListType.CREATED).size());
  
  INode fooNode = fsdir.getINode4Write(foo.toString());
  assertTrue(fooNode.isDirectory() && fooNode.asDirectory().isWithSnapshot());
  List<DirectoryDiff> fooDiffs = fooNode.asDirectory().getDiffs().asList();
  assertEquals(1, fooDiffs.size());
  assertEquals(s1.getId(), fooDiffs.get(0).getSnapshotId());
  
  final Path foo_s1 = SnapshotTestHelper.getSnapshotPath(sdir1, "s1", "foo");
  INode fooNode_s1 = fsdir.getINode(foo_s1.toString());
  assertTrue(fooNode_s1 == fooNode);
  
  // check sdir2
  assertFalse(hdfs.exists(newfoo));
  INodeDirectory dir2Node = fsdir.getINode4Write(sdir2.toString())
      .asDirectory();
  assertFalse(dir2Node.isWithSnapshot());
  ReadOnlyList<INode> dir2Children = dir2Node
      .getChildrenList(Snapshot.CURRENT_STATE_ID);
  assertEquals(1, dir2Children.size());
  assertEquals(dir2file.getName(), dir2Children.get(0).getLocalName());
}
 

/**
 * Scan all CacheDirectives.  Use the information to figure out
 * what cache replication factor each block should have.
 */
private void rescanCacheDirectives() {
  FSDirectory fsDir = namesystem.getFSDirectory();
  final long now = new Date().getTime();
  for (CacheDirective directive : cacheManager.getCacheDirectives()) {
    scannedDirectives++;
    // Skip processing this entry if it has expired
    if (directive.getExpiryTime() > 0 && directive.getExpiryTime() <= now) {
      LOG.debug("Directive {}: the directive expired at {} (now = {})",
           directive.getId(), directive.getExpiryTime(), now);
      continue;
    }
    String path = directive.getPath();
    INode node;
    try {
      node = fsDir.getINode(path);
    } catch (UnresolvedLinkException e) {
      // We don't cache through symlinks
      LOG.debug("Directive {}: got UnresolvedLinkException while resolving "
              + "path {}", directive.getId(), path
      );
      continue;
    }
    if (node == null)  {
      LOG.debug("Directive {}: No inode found at {}", directive.getId(),
          path);
    } else if (node.isDirectory()) {
      INodeDirectory dir = node.asDirectory();
      ReadOnlyList<INode> children = dir
          .getChildrenList(Snapshot.CURRENT_STATE_ID);
      for (INode child : children) {
        if (child.isFile()) {
          rescanFile(directive, child.asFile());
        }
      }
    } else if (node.isFile()) {
      rescanFile(directive, node.asFile());
    } else {
      LOG.debug("Directive {}: ignoring non-directive, non-file inode {} ",
          directive.getId(), node);
    }
  }
}
 

/**
 * Clean an inode while we move it from the deleted list of post to the
 * deleted list of prior.
 * @param bsps The block storage policy suite.
 * @param inode The inode to clean.
 * @param post The post snapshot.
 * @param prior The id of the prior snapshot.
 * @param collectedBlocks Used to collect blocks for later deletion.
 * @return Quota usage update.
 */
private static QuotaCounts cleanDeletedINode(
    final BlockStoragePolicySuite bsps, INode inode,
    final int post, final int prior,
    final BlocksMapUpdateInfo collectedBlocks,
    final List<INode> removedINodes) {
  QuotaCounts counts = new QuotaCounts.Builder().build();
  Deque<INode> queue = new ArrayDeque<INode>();
  queue.addLast(inode);
  while (!queue.isEmpty()) {
    INode topNode = queue.pollFirst();
    if (topNode instanceof INodeReference.WithName) {
      INodeReference.WithName wn = (INodeReference.WithName) topNode;
      if (wn.getLastSnapshotId() >= post) {
        wn.cleanSubtree(bsps, post, prior, collectedBlocks, removedINodes);
      }
      // For DstReference node, since the node is not in the created list of
      // prior, we should treat it as regular file/dir
    } else if (topNode.isFile() && topNode.asFile().isWithSnapshot()) {
      INodeFile file = topNode.asFile();
      counts.add(file.getDiffs().deleteSnapshotDiff(bsps, post, prior, file,
          collectedBlocks, removedINodes));
    } else if (topNode.isDirectory()) {
      INodeDirectory dir = topNode.asDirectory();
      ChildrenDiff priorChildrenDiff = null;
      DirectoryWithSnapshotFeature sf = dir.getDirectoryWithSnapshotFeature();
      if (sf != null) {
        // delete files/dirs created after prior. Note that these
        // files/dirs, along with inode, were deleted right after post.
        DirectoryDiff priorDiff = sf.getDiffs().getDiffById(prior);
        if (priorDiff != null && priorDiff.getSnapshotId() == prior) {
          priorChildrenDiff = priorDiff.getChildrenDiff();
          counts.add(priorChildrenDiff.destroyCreatedList(bsps, dir,
              collectedBlocks, removedINodes));
        }
      }
      
      for (INode child : dir.getChildrenList(prior)) {
        if (priorChildrenDiff != null
            && priorChildrenDiff.search(ListType.DELETED,
                child.getLocalNameBytes()) != null) {
          continue;
        }
        queue.addLast(child);
      }
    }
  }
  return counts;
}
 

/**
 * After the following operations:
 * Rename a dir -> create a snapshot s on dst tree -> rename the renamed dir
 * again -> delete snapshot s on dst tree
 * 
 * Make sure we only delete the snapshot s under the renamed dir.
 */
@Test
public void testRenameDirAndDeleteSnapshot_4() throws Exception {
  final Path sdir1 = new Path("/dir1");
  final Path sdir2 = new Path("/dir2");
  final Path foo = new Path(sdir1, "foo");
  final Path bar = new Path(foo, "bar");
  DFSTestUtil.createFile(hdfs, bar, BLOCKSIZE, REPL, SEED);
  hdfs.mkdirs(sdir2);
  
  SnapshotTestHelper.createSnapshot(hdfs, sdir1, "s1");
  SnapshotTestHelper.createSnapshot(hdfs, sdir2, "s2");
  
  final Path foo2 = new Path(sdir2, "foo");
  hdfs.rename(foo, foo2);
  
  // create two new files under foo2
  final Path bar2 = new Path(foo2, "bar2");
  DFSTestUtil.createFile(hdfs, bar2, BLOCKSIZE, REPL, SEED);
  final Path bar3 = new Path(foo2, "bar3");
  DFSTestUtil.createFile(hdfs, bar3, BLOCKSIZE, REPL, SEED);
  
  // create a new snapshot on sdir2
  hdfs.createSnapshot(sdir2, "s3");
  
  // rename foo2 again
  hdfs.rename(foo2, foo);
  // delete snapshot s3
  hdfs.deleteSnapshot(sdir2, "s3");
  
  // check
  final INodeDirectory dir1Node = fsdir.getINode4Write(sdir1.toString())
      .asDirectory();
  // sdir1 + s1 + foo_s1 (foo) + foo (foo + s1 + bar~bar3)
  QuotaCounts q1 = dir1Node.getDirectoryWithQuotaFeature().getSpaceConsumed();
  assertEquals(7, q1.getNameSpace());
  final INodeDirectory dir2Node = fsdir.getINode4Write(sdir2.toString())
      .asDirectory();
  QuotaCounts q2 = dir2Node.getDirectoryWithQuotaFeature().getSpaceConsumed();
  assertEquals(1, q2.getNameSpace());
  
  final Path foo_s1 = SnapshotTestHelper.getSnapshotPath(sdir1, "s1",
      foo.getName());
  final INode fooRef = fsdir.getINode(foo_s1.toString());
  assertTrue(fooRef instanceof INodeReference.WithName);
  INodeReference.WithCount wc = 
      (WithCount) fooRef.asReference().getReferredINode();
  assertEquals(2, wc.getReferenceCount());
  INodeDirectory fooNode = wc.getReferredINode().asDirectory();
  ReadOnlyList<INode> children = fooNode
      .getChildrenList(Snapshot.CURRENT_STATE_ID);
  assertEquals(3, children.size());
  assertEquals(bar.getName(), children.get(0).getLocalName());
  assertEquals(bar2.getName(), children.get(1).getLocalName());
  assertEquals(bar3.getName(), children.get(2).getLocalName());
  List<DirectoryDiff> diffList = fooNode.getDiffs().asList();
  assertEquals(1, diffList.size());
  Snapshot s1 = dir1Node.getSnapshot(DFSUtil.string2Bytes("s1"));
  assertEquals(s1.getId(), diffList.get(0).getSnapshotId());
  ChildrenDiff diff = diffList.get(0).getChildrenDiff();
  // bar2 and bar3 in the created list
  assertEquals(2, diff.getList(ListType.CREATED).size());
  assertEquals(0, diff.getList(ListType.DELETED).size());
  
  final INode fooRef2 = fsdir.getINode4Write(foo.toString());
  assertTrue(fooRef2 instanceof INodeReference.DstReference);
  INodeReference.WithCount wc2 = 
      (WithCount) fooRef2.asReference().getReferredINode();
  assertSame(wc, wc2);
  assertSame(fooRef2, wc.getParentReference());
  
  restartClusterAndCheckImage(true);
}
 

/**
 * After the following operations:
 * Rename a dir -> create a snapshot s on dst tree -> delete the renamed dir
 * -> delete snapshot s on dst tree
 * 
 * Make sure we destroy everything created after the rename under the renamed
 * dir.
 */
@Test
public void testRenameDirAndDeleteSnapshot_3() throws Exception {
  final Path sdir1 = new Path("/dir1");
  final Path sdir2 = new Path("/dir2");
  final Path foo = new Path(sdir1, "foo");
  final Path bar = new Path(foo, "bar");
  DFSTestUtil.createFile(hdfs, bar, BLOCKSIZE, REPL, SEED);
  hdfs.mkdirs(sdir2);
  
  SnapshotTestHelper.createSnapshot(hdfs, sdir1, "s1");
  SnapshotTestHelper.createSnapshot(hdfs, sdir2, "s2");
  
  final Path foo2 = new Path(sdir2, "foo");
  hdfs.rename(foo, foo2);
  
  // create two new files under foo2
  final Path bar2 = new Path(foo2, "bar2");
  DFSTestUtil.createFile(hdfs, bar2, BLOCKSIZE, REPL, SEED);
  final Path bar3 = new Path(foo2, "bar3");
  DFSTestUtil.createFile(hdfs, bar3, BLOCKSIZE, REPL, SEED);
  
  // create a new snapshot on sdir2
  hdfs.createSnapshot(sdir2, "s3");
  
  // delete foo2
  hdfs.delete(foo2, true);
  // delete s3
  hdfs.deleteSnapshot(sdir2, "s3");
  
  // check
  final INodeDirectory dir1Node = fsdir.getINode4Write(sdir1.toString())
      .asDirectory();
  QuotaCounts q1 = dir1Node.getDirectoryWithQuotaFeature().getSpaceConsumed();
  assertEquals(3, q1.getNameSpace());
  final INodeDirectory dir2Node = fsdir.getINode4Write(sdir2.toString())
      .asDirectory();
  QuotaCounts q2 = dir2Node.getDirectoryWithQuotaFeature().getSpaceConsumed();
  assertEquals(1, q2.getNameSpace());
  
  final Path foo_s1 = SnapshotTestHelper.getSnapshotPath(sdir1, "s1",
      foo.getName());
  INode fooRef = fsdir.getINode(foo_s1.toString());
  assertTrue(fooRef instanceof INodeReference.WithName);
  INodeReference.WithCount wc = 
      (WithCount) fooRef.asReference().getReferredINode();
  assertEquals(1, wc.getReferenceCount());
  INodeDirectory fooNode = wc.getReferredINode().asDirectory();
  ReadOnlyList<INode> children = fooNode
      .getChildrenList(Snapshot.CURRENT_STATE_ID);
  assertEquals(1, children.size());
  assertEquals(bar.getName(), children.get(0).getLocalName());
  List<DirectoryDiff> diffList = fooNode.getDiffs().asList();
  assertEquals(1, diffList.size());
  Snapshot s1 = dir1Node.getSnapshot(DFSUtil.string2Bytes("s1"));
  assertEquals(s1.getId(), diffList.get(0).getSnapshotId());
  ChildrenDiff diff = diffList.get(0).getChildrenDiff();
  assertEquals(0, diff.getList(ListType.CREATED).size());
  assertEquals(0, diff.getList(ListType.DELETED).size());
  
  restartClusterAndCheckImage(true);
}
 

/**
 * Test rename to an invalid name (xxx/.snapshot)
 */
@Test
public void testRenameUndo_7() throws Exception {
  final Path root = new Path("/");
  final Path foo = new Path(root, "foo");
  final Path bar = new Path(foo, "bar");
  DFSTestUtil.createFile(hdfs, bar, BLOCKSIZE, REPL, SEED);
  
  // create a snapshot on root
  SnapshotTestHelper.createSnapshot(hdfs, root, snap1);
  
  // rename bar to /foo/.snapshot which is invalid
  final Path invalid = new Path(foo, HdfsConstants.DOT_SNAPSHOT_DIR);
  try {
    hdfs.rename(bar, invalid);
    fail("expect exception since invalid name is used for rename");
  } catch (Exception e) {
    GenericTestUtils.assertExceptionContains("\"" +
        HdfsConstants.DOT_SNAPSHOT_DIR + "\" is a reserved name", e);
  }
  
  // check
  INodeDirectory rootNode = fsdir.getINode4Write(root.toString())
      .asDirectory();
  INodeDirectory fooNode = fsdir.getINode4Write(foo.toString()).asDirectory();
  ReadOnlyList<INode> children = fooNode
      .getChildrenList(Snapshot.CURRENT_STATE_ID);
  assertEquals(1, children.size());
  List<DirectoryDiff> diffList = fooNode.getDiffs().asList();
  assertEquals(1, diffList.size());
  DirectoryDiff diff = diffList.get(0);
  // this diff is generated while renaming
  Snapshot s1 = rootNode.getSnapshot(DFSUtil.string2Bytes(snap1));
  assertEquals(s1.getId(), diff.getSnapshotId());
  // after undo, the diff should be empty
  assertTrue(diff.getChildrenDiff().getList(ListType.DELETED).isEmpty());
  assertTrue(diff.getChildrenDiff().getList(ListType.CREATED).isEmpty());
  
  // bar was converted to filewithsnapshot while renaming
  INodeFile barNode = fsdir.getINode4Write(bar.toString()).asFile();
  assertSame(barNode, children.get(0));
  assertSame(fooNode, barNode.getParent());
  List<FileDiff> barDiffList = barNode.getDiffs().asList();
  assertEquals(1, barDiffList.size());
  FileDiff barDiff = barDiffList.get(0);
  assertEquals(s1.getId(), barDiff.getSnapshotId());
  
  // restart cluster multiple times to make sure the fsimage and edits log are
  // correct. Note that when loading fsimage, foo and bar will be converted 
  // back to normal INodeDirectory and INodeFile since they do not store any 
  // snapshot data
  hdfs.setSafeMode(SafeModeAction.SAFEMODE_ENTER);
  hdfs.saveNamespace();
  hdfs.setSafeMode(SafeModeAction.SAFEMODE_LEAVE);
  cluster.shutdown();
  cluster = new MiniDFSCluster.Builder(conf).format(false)
      .numDataNodes(REPL).build();
  cluster.waitActive();
  restartClusterAndCheckImage(true);
}
 

/**
 * Test the undo section of the second-time rename.
 */
@Test
public void testRenameUndo_3() throws Exception {
  final Path sdir1 = new Path("/dir1");
  final Path sdir2 = new Path("/dir2");
  final Path sdir3 = new Path("/dir3");
  hdfs.mkdirs(sdir1);
  hdfs.mkdirs(sdir2);
  hdfs.mkdirs(sdir3);
  final Path foo = new Path(sdir1, "foo");
  final Path bar = new Path(foo, "bar");
  DFSTestUtil.createFile(hdfs, bar, BLOCKSIZE, REPL, SEED);
  
  SnapshotTestHelper.createSnapshot(hdfs, sdir1, "s1");
  SnapshotTestHelper.createSnapshot(hdfs, sdir2, "s2");
  
  INodeDirectory dir3 = fsdir.getINode4Write(sdir3.toString()).asDirectory();
  INodeDirectory mockDir3 = spy(dir3);
  doReturn(false).when(mockDir3).addChild((INode) anyObject(), anyBoolean(),
          Mockito.anyInt());
  INodeDirectory root = fsdir.getINode4Write("/").asDirectory();
  root.replaceChild(dir3, mockDir3, fsdir.getINodeMap());
  
  final Path foo_dir2 = new Path(sdir2, "foo2");
  final Path foo_dir3 = new Path(sdir3, "foo3");
  hdfs.rename(foo, foo_dir2);
  boolean result = hdfs.rename(foo_dir2, foo_dir3);
  assertFalse(result);
  
  // check the current internal details
  INodeDirectory dir1Node = fsdir.getINode4Write(sdir1.toString())
      .asDirectory();
  Snapshot s1 = dir1Node.getSnapshot(DFSUtil.string2Bytes("s1"));
  INodeDirectory dir2Node = fsdir.getINode4Write(sdir2.toString())
      .asDirectory();
  Snapshot s2 = dir2Node.getSnapshot(DFSUtil.string2Bytes("s2"));
  ReadOnlyList<INode> dir2Children = dir2Node
      .getChildrenList(Snapshot.CURRENT_STATE_ID);
  assertEquals(1, dir2Children.size());
  List<DirectoryDiff> dir2Diffs = dir2Node.getDiffs().asList();
  assertEquals(1, dir2Diffs.size());
  assertEquals(s2.getId(), dir2Diffs.get(0).getSnapshotId());
  ChildrenDiff childrenDiff = dir2Diffs.get(0).getChildrenDiff();
  assertEquals(0, childrenDiff.getList(ListType.DELETED).size());
  assertEquals(1, childrenDiff.getList(ListType.CREATED).size());
  final Path foo_s2 = SnapshotTestHelper.getSnapshotPath(sdir2, "s2", "foo2");
  assertFalse(hdfs.exists(foo_s2));
  
  INode fooNode = fsdir.getINode4Write(foo_dir2.toString());
  assertTrue(childrenDiff.getList(ListType.CREATED).get(0) == fooNode);
  assertTrue(fooNode instanceof INodeReference.DstReference);
  List<DirectoryDiff> fooDiffs = fooNode.asDirectory().getDiffs().asList();
  assertEquals(1, fooDiffs.size());
  assertEquals(s1.getId(), fooDiffs.get(0).getSnapshotId());
  
  // create snapshot on sdir2 and rename again
  hdfs.createSnapshot(sdir2, "s3");
  result = hdfs.rename(foo_dir2, foo_dir3);
  assertFalse(result);

  // check internal details again
  dir2Node = fsdir.getINode4Write(sdir2.toString()).asDirectory();
  Snapshot s3 = dir2Node.getSnapshot(DFSUtil.string2Bytes("s3"));
  fooNode = fsdir.getINode4Write(foo_dir2.toString());
  dir2Children = dir2Node.getChildrenList(Snapshot.CURRENT_STATE_ID);
  assertEquals(1, dir2Children.size());
  dir2Diffs = dir2Node.getDiffs().asList();
  assertEquals(2, dir2Diffs.size());
  assertEquals(s2.getId(), dir2Diffs.get(0).getSnapshotId());
  assertEquals(s3.getId(), dir2Diffs.get(1).getSnapshotId());
  
  childrenDiff = dir2Diffs.get(0).getChildrenDiff();
  assertEquals(0, childrenDiff.getList(ListType.DELETED).size());
  assertEquals(1, childrenDiff.getList(ListType.CREATED).size());
  assertTrue(childrenDiff.getList(ListType.CREATED).get(0) == fooNode);
  
  childrenDiff = dir2Diffs.get(1).getChildrenDiff();
  assertEquals(0, childrenDiff.getList(ListType.DELETED).size());
  assertEquals(0, childrenDiff.getList(ListType.CREATED).size());
  
  final Path foo_s3 = SnapshotTestHelper.getSnapshotPath(sdir2, "s3", "foo2");
  assertFalse(hdfs.exists(foo_s2));
  assertTrue(hdfs.exists(foo_s3));
  
  assertTrue(fooNode instanceof INodeReference.DstReference);
  fooDiffs = fooNode.asDirectory().getDiffs().asList();
  assertEquals(2, fooDiffs.size());
  assertEquals(s1.getId(), fooDiffs.get(0).getSnapshotId());
  assertEquals(s3.getId(), fooDiffs.get(1).getSnapshotId());
}
 

/**
 * Test the undo section of rename. Before the rename, we create the renamed 
 * file/dir after taking the snapshot.
 */
@Test
public void testRenameUndo_2() throws Exception {
  final Path sdir1 = new Path("/dir1");
  final Path sdir2 = new Path("/dir2");
  hdfs.mkdirs(sdir1);
  hdfs.mkdirs(sdir2);
  final Path dir2file = new Path(sdir2, "file");
  DFSTestUtil.createFile(hdfs, dir2file, BLOCKSIZE, REPL, SEED);
  
  SnapshotTestHelper.createSnapshot(hdfs, sdir1, "s1");
  
  // create foo after taking snapshot
  final Path foo = new Path(sdir1, "foo");
  final Path bar = new Path(foo, "bar");
  DFSTestUtil.createFile(hdfs, bar, BLOCKSIZE, REPL, SEED);
  
  INodeDirectory dir2 = fsdir.getINode4Write(sdir2.toString()).asDirectory();
  INodeDirectory mockDir2 = spy(dir2);
  doReturn(false).when(mockDir2).addChild((INode) anyObject(), anyBoolean(),
          Mockito.anyInt());
  INodeDirectory root = fsdir.getINode4Write("/").asDirectory();
  root.replaceChild(dir2, mockDir2, fsdir.getINodeMap());
  
  final Path newfoo = new Path(sdir2, "foo");
  boolean result = hdfs.rename(foo, newfoo);
  assertFalse(result);
  
  // check the current internal details
  INodeDirectory dir1Node = fsdir.getINode4Write(sdir1.toString())
      .asDirectory();
  Snapshot s1 = dir1Node.getSnapshot(DFSUtil.string2Bytes("s1"));
  ReadOnlyList<INode> dir1Children = dir1Node
      .getChildrenList(Snapshot.CURRENT_STATE_ID);
  assertEquals(1, dir1Children.size());
  assertEquals(foo.getName(), dir1Children.get(0).getLocalName());
  List<DirectoryDiff> dir1Diffs = dir1Node.getDiffs().asList();
  assertEquals(1, dir1Diffs.size());
  assertEquals(s1.getId(), dir1Diffs.get(0).getSnapshotId());
  
  // after the undo of rename, the created list of sdir1 should contain 
  // 1 element
  ChildrenDiff childrenDiff = dir1Diffs.get(0).getChildrenDiff();
  assertEquals(0, childrenDiff.getList(ListType.DELETED).size());
  assertEquals(1, childrenDiff.getList(ListType.CREATED).size());
  
  INode fooNode = fsdir.getINode4Write(foo.toString());
  assertTrue(fooNode instanceof INodeDirectory);
  assertTrue(childrenDiff.getList(ListType.CREATED).get(0) == fooNode);
  
  final Path foo_s1 = SnapshotTestHelper.getSnapshotPath(sdir1, "s1", "foo");
  assertFalse(hdfs.exists(foo_s1));
  
  // check sdir2
  assertFalse(hdfs.exists(newfoo));
  INodeDirectory dir2Node = fsdir.getINode4Write(sdir2.toString())
      .asDirectory();
  assertFalse(dir2Node.isWithSnapshot());
  ReadOnlyList<INode> dir2Children = dir2Node
      .getChildrenList(Snapshot.CURRENT_STATE_ID);
  assertEquals(1, dir2Children.size());
  assertEquals(dir2file.getName(), dir2Children.get(0).getLocalName());
}
 

/**
 * Test the undo section of rename. Before the rename, we create the renamed 
 * file/dir before taking the snapshot.
 */
@Test
public void testRenameUndo_1() throws Exception {
  final Path sdir1 = new Path("/dir1");
  final Path sdir2 = new Path("/dir2");
  hdfs.mkdirs(sdir1);
  hdfs.mkdirs(sdir2);
  final Path foo = new Path(sdir1, "foo");
  final Path bar = new Path(foo, "bar");
  DFSTestUtil.createFile(hdfs, bar, BLOCKSIZE, REPL, SEED);
  final Path dir2file = new Path(sdir2, "file");
  DFSTestUtil.createFile(hdfs, dir2file, BLOCKSIZE, REPL, SEED);
  
  SnapshotTestHelper.createSnapshot(hdfs, sdir1, "s1");
  
  INodeDirectory dir2 = fsdir.getINode4Write(sdir2.toString()).asDirectory();
  INodeDirectory mockDir2 = spy(dir2);
  doReturn(false).when(mockDir2).addChild((INode) anyObject(), anyBoolean(),
         Mockito.anyInt());
  INodeDirectory root = fsdir.getINode4Write("/").asDirectory();
  root.replaceChild(dir2, mockDir2, fsdir.getINodeMap());
  
  final Path newfoo = new Path(sdir2, "foo");
  boolean result = hdfs.rename(foo, newfoo);
  assertFalse(result);
  
  // check the current internal details
  INodeDirectory dir1Node = fsdir.getINode4Write(sdir1.toString())
      .asDirectory();
  Snapshot s1 = dir1Node.getSnapshot(DFSUtil.string2Bytes("s1"));
  ReadOnlyList<INode> dir1Children = dir1Node
      .getChildrenList(Snapshot.CURRENT_STATE_ID);
  assertEquals(1, dir1Children.size());
  assertEquals(foo.getName(), dir1Children.get(0).getLocalName());
  List<DirectoryDiff> dir1Diffs = dir1Node.getDiffs().asList();
  assertEquals(1, dir1Diffs.size());
  assertEquals(s1.getId(), dir1Diffs.get(0).getSnapshotId());
  
  // after the undo of rename, both the created and deleted list of sdir1
  // should be empty
  ChildrenDiff childrenDiff = dir1Diffs.get(0).getChildrenDiff();
  assertEquals(0, childrenDiff.getList(ListType.DELETED).size());
  assertEquals(0, childrenDiff.getList(ListType.CREATED).size());
  
  INode fooNode = fsdir.getINode4Write(foo.toString());
  assertTrue(fooNode.isDirectory() && fooNode.asDirectory().isWithSnapshot());
  List<DirectoryDiff> fooDiffs = fooNode.asDirectory().getDiffs().asList();
  assertEquals(1, fooDiffs.size());
  assertEquals(s1.getId(), fooDiffs.get(0).getSnapshotId());
  
  final Path foo_s1 = SnapshotTestHelper.getSnapshotPath(sdir1, "s1", "foo");
  INode fooNode_s1 = fsdir.getINode(foo_s1.toString());
  assertTrue(fooNode_s1 == fooNode);
  
  // check sdir2
  assertFalse(hdfs.exists(newfoo));
  INodeDirectory dir2Node = fsdir.getINode4Write(sdir2.toString())
      .asDirectory();
  assertFalse(dir2Node.isWithSnapshot());
  ReadOnlyList<INode> dir2Children = dir2Node
      .getChildrenList(Snapshot.CURRENT_STATE_ID);
  assertEquals(1, dir2Children.size());
  assertEquals(dir2file.getName(), dir2Children.get(0).getLocalName());
}
 

/**
 * Scan all CacheDirectives.  Use the information to figure out
 * what cache replication factor each block should have.
 */
private void rescanCacheDirectives() {
  FSDirectory fsDir = namesystem.getFSDirectory();
  final long now = new Date().getTime();
  for (CacheDirective directive : cacheManager.getCacheDirectives()) {
    scannedDirectives++;
    // Skip processing this entry if it has expired
    if (directive.getExpiryTime() > 0 && directive.getExpiryTime() <= now) {
      LOG.debug("Directive {}: the directive expired at {} (now = {})",
           directive.getId(), directive.getExpiryTime(), now);
      continue;
    }
    String path = directive.getPath();
    INode node;
    try {
      node = fsDir.getINode(path);
    } catch (UnresolvedLinkException e) {
      // We don't cache through symlinks
      LOG.debug("Directive {}: got UnresolvedLinkException while resolving "
              + "path {}", directive.getId(), path
      );
      continue;
    }
    if (node == null)  {
      LOG.debug("Directive {}: No inode found at {}", directive.getId(),
          path);
    } else if (node.isDirectory()) {
      INodeDirectory dir = node.asDirectory();
      ReadOnlyList<INode> children = dir
          .getChildrenList(Snapshot.CURRENT_STATE_ID);
      for (INode child : children) {
        if (child.isFile()) {
          rescanFile(directive, child.asFile());
        }
      }
    } else if (node.isFile()) {
      rescanFile(directive, node.asFile());
    } else {
      LOG.debug("Directive {}: ignoring non-directive, non-file inode {} ",
          directive.getId(), node);
    }
  }
}