/// <summary>Rename a snapshot</summary>
/// <param name="path">
/// The directory path where the snapshot was taken. Used for
/// generating exception message.
/// </param>
/// <param name="oldName">Old name of the snapshot</param>
/// <param name="newName">New name the snapshot will be renamed to</param>
/// <exception cref="Org.Apache.Hadoop.Hdfs.Protocol.SnapshotException">
/// Throw SnapshotException when either the snapshot with the old
/// name does not exist or a snapshot with the new name already
/// exists
/// </exception>
public virtual void RenameSnapshot(string path, string oldName, string newName)
{
if (newName.Equals(oldName))
{
return;
}
int indexOfOld = SearchSnapshot(DFSUtil.String2Bytes(oldName));
if (indexOfOld < 0)
{
throw new SnapshotException("The snapshot " + oldName + " does not exist for directory "
+ path);
}
else
{
byte[] newNameBytes = DFSUtil.String2Bytes(newName);
int indexOfNew = SearchSnapshot(newNameBytes);
if (indexOfNew >= 0)
{
throw new SnapshotException("The snapshot " + newName + " already exists for directory "
+ path);
}
// remove the one with old name from snapshotsByNames
Org.Apache.Hadoop.Hdfs.Server.Namenode.Snapshot.Snapshot snapshot = snapshotsByNames
.Remove(indexOfOld);
INodeDirectory ssRoot = snapshot.GetRoot();
ssRoot.SetLocalName(newNameBytes);
indexOfNew = -indexOfNew - 1;
if (indexOfNew <= indexOfOld)
{
snapshotsByNames.Add(indexOfNew, snapshot);
}
else
{
// indexOfNew > indexOfOld
snapshotsByNames.Add(indexOfNew - 1, snapshot);
}
}
}