import org.apache.hadoop.hdfs.server.namenode.snapshot.Snapshot.Root; //导入依赖的package包/类
/**
 * Get a listing of all the snapshots of a snapshottable directory
 */
private DirectoryListing getSnapshotsListing(String src, byte[] startAfter)
    throws UnresolvedLinkException, IOException {
  Preconditions.checkState(hasReadLock());
  Preconditions.checkArgument(
      src.endsWith(HdfsConstants.SEPARATOR_DOT_SNAPSHOT_DIR), 
      "%s does not end with %s", src, HdfsConstants.SEPARATOR_DOT_SNAPSHOT_DIR);
  
  final String dirPath = normalizePath(src.substring(0,
      src.length() - HdfsConstants.DOT_SNAPSHOT_DIR.length()));
  
  final INode node = this.getINode(dirPath);
  final INodeDirectorySnapshottable dirNode = INodeDirectorySnapshottable
      .valueOf(node, dirPath);
  final ReadOnlyList<Snapshot> snapshots = dirNode.getSnapshotList();
  int skipSize = ReadOnlyList.Util.binarySearch(snapshots, startAfter);
  skipSize = skipSize < 0 ? -skipSize - 1 : skipSize + 1;
  int numOfListing = Math.min(snapshots.size() - skipSize, this.lsLimit);
  final HdfsFileStatus listing[] = new HdfsFileStatus[numOfListing];
  for (int i = 0; i < numOfListing; i++) {
    Root sRoot = snapshots.get(i + skipSize).getRoot();
    listing[i] = createFileStatus(sRoot.getLocalNameBytes(), sRoot, null);
  }
  return new DirectoryListing(
      listing, snapshots.size() - skipSize - numOfListing);
}
 

import org.apache.hadoop.hdfs.server.namenode.snapshot.Snapshot.Root; //导入依赖的package包/类
/**
 * Get a listing of all the snapshots of a snapshottable directory
 */
private DirectoryListing getSnapshotsListing(String src, byte[] startAfter)
    throws UnresolvedLinkException, IOException {
  Preconditions.checkState(hasReadLock());
  Preconditions.checkArgument(
      src.endsWith(HdfsConstants.SEPARATOR_DOT_SNAPSHOT_DIR),
      "%s does not end with %s", src, HdfsConstants.SEPARATOR_DOT_SNAPSHOT_DIR);

  final String dirPath = normalizePath(src.substring(0,
      src.length() - HdfsConstants.DOT_SNAPSHOT_DIR.length()));
  
  final INode node = this.getINode(dirPath);
  final INodeDirectory dirNode = INodeDirectory.valueOf(node, dirPath);
  final DirectorySnapshottableFeature sf = dirNode.getDirectorySnapshottableFeature();
  if (sf == null) {
    throw new SnapshotException(
        "Directory is not a snapshottable directory: " + dirPath);
  }
  final ReadOnlyList<Snapshot> snapshots = sf.getSnapshotList();
  int skipSize = ReadOnlyList.Util.binarySearch(snapshots, startAfter);
  skipSize = skipSize < 0 ? -skipSize - 1 : skipSize + 1;
  int numOfListing = Math.min(snapshots.size() - skipSize, this.lsLimit);
  final HdfsFileStatus listing[] = new HdfsFileStatus[numOfListing];
  for (int i = 0; i < numOfListing; i++) {
    Root sRoot = snapshots.get(i + skipSize).getRoot();
    listing[i] = createFileStatus(sRoot.getLocalNameBytes(), sRoot,
        BlockStoragePolicySuite.ID_UNSPECIFIED, Snapshot.CURRENT_STATE_ID,
        false, null);
  }
  return new DirectoryListing(
      listing, snapshots.size() - skipSize - numOfListing);
}
 

import org.apache.hadoop.hdfs.server.namenode.snapshot.Snapshot.Root; //导入依赖的package包/类
/**
 * Get a listing of all the snapshots of a snapshottable directory
 */
private DirectoryListing getSnapshotsListing(String src, byte[] startAfter)
    throws UnresolvedLinkException, IOException {
  Preconditions.checkState(hasReadLock());
  Preconditions.checkArgument(
      src.endsWith(HdfsConstants.SEPARATOR_DOT_SNAPSHOT_DIR), 
      "%s does not end with %s", src, HdfsConstants.SEPARATOR_DOT_SNAPSHOT_DIR);
  
  final String dirPath = normalizePath(src.substring(0,
      src.length() - HdfsConstants.DOT_SNAPSHOT_DIR.length()));
  
  final INode node = this.getINode(dirPath);
  final INodeDirectorySnapshottable dirNode = INodeDirectorySnapshottable
      .valueOf(node, dirPath);
  final ReadOnlyList<Snapshot> snapshots = dirNode.getSnapshotList();
  int skipSize = ReadOnlyList.Util.binarySearch(snapshots, startAfter);
  skipSize = skipSize < 0 ? -skipSize - 1 : skipSize + 1;
  int numOfListing = Math.min(snapshots.size() - skipSize, this.lsLimit);
  final HdfsFileStatus listing[] = new HdfsFileStatus[numOfListing];
  for (int i = 0; i < numOfListing; i++) {
    Root sRoot = snapshots.get(i + skipSize).getRoot();
    listing[i] = createFileStatus(sRoot.getLocalNameBytes(), sRoot,
        Snapshot.CURRENT_STATE_ID);
  }
  return new DirectoryListing(
      listing, snapshots.size() - skipSize - numOfListing);
}