Lucene.Net.Index.IndexReader.ListCommits C# (CSharp) Method

		public static System.Collections.Generic.ICollection<IndexCommit> ListCommits(Directory dir)
		{
			return DirectoryReader.ListCommits(dir);
		}

        //Rolls back index to a chosen ID
        private void  RollBackLast(int id)
        {
            // System.out.println("Attempting to rollback to "+id);
            System.String ids  = "-" + id;
            IndexCommit   last = null;

            System.Collections.ICollection commits = IndexReader.ListCommits(dir);
            for (System.Collections.IEnumerator iterator = commits.GetEnumerator(); iterator.MoveNext();)
            {
                IndexCommit commit = (IndexCommit)iterator.Current;
                System.Collections.Generic.IDictionary <string, string> ud = commit.GetUserData();
                if (ud.Count > 0)
                {
                    if (((System.String)ud["index"]).EndsWith(ids))
                    {
                        last = commit;
                    }
                }
            }

            if (last == null)
            {
                throw new System.SystemException("Couldn't find commit point " + id);
            }

            IndexWriter w = new IndexWriter(dir, new WhitespaceAnalyzer(), new RollbackDeletionPolicy(this, id), MaxFieldLength.UNLIMITED, last);

            System.Collections.Generic.IDictionary <string, string> data = new System.Collections.Generic.Dictionary <string, string>();
            data["index"] = "Rolled back to 1-" + id;
            w.Commit(data);
            w.Close();
        }