/// <exception cref="NGit.Errors.TransportException"></exception>
        private void Sendpack(IList <RemoteRefUpdate> updates, ProgressMonitor monitor)
        {
            string     pathPack = null;
            string     pathIdx  = null;
            PackWriter writer   = new PackWriter(transport.GetPackConfig(), local.NewObjectReader
                                                     ());

            try
            {
                ICollection <ObjectId> need = new HashSet <ObjectId>();
                ICollection <ObjectId> have = new HashSet <ObjectId>();
                foreach (RemoteRefUpdate r in updates)
                {
                    need.AddItem(r.GetNewObjectId());
                }
                foreach (Ref r_1 in GetRefs())
                {
                    have.AddItem(r_1.GetObjectId());
                    if (r_1.GetPeeledObjectId() != null)
                    {
                        have.AddItem(r_1.GetPeeledObjectId());
                    }
                }
                writer.PreparePack(monitor, need, have);
                // We don't have to continue further if the pack will
                // be an empty pack, as the remote has all objects it
                // needs to complete this change.
                //
                if (writer.GetObjectCount() == 0)
                {
                    return;
                }
                packNames = new LinkedHashMap <string, string>();
                foreach (string n in dest.GetPackNames())
                {
                    packNames.Put(n, n);
                }
                string @base    = "pack-" + writer.ComputeName().Name;
                string packName = @base + ".pack";
                pathPack = "pack/" + packName;
                pathIdx  = "pack/" + @base + ".idx";
                if (Sharpen.Collections.Remove(packNames, packName) != null)
                {
                    // The remote already contains this pack. We should
                    // remove the index before overwriting to prevent bad
                    // offsets from appearing to clients.
                    //
                    dest.WriteInfoPacks(packNames.Keys);
                    dest.DeleteFile(pathIdx);
                }
                // Write the pack file, then the index, as readers look the
                // other direction (index, then pack file).
                //
                string       wt = "Put " + Sharpen.Runtime.Substring(@base, 0, 12);
                OutputStream os = dest.WriteFile(pathPack, monitor, wt + "..pack");
                try
                {
                    os = new SafeBufferedOutputStream(os);
                    writer.WritePack(monitor, monitor, os);
                }
                finally
                {
                    os.Close();
                }
                os = dest.WriteFile(pathIdx, monitor, wt + "..idx");
                try
                {
                    os = new SafeBufferedOutputStream(os);
                    writer.WriteIndex(os);
                }
                finally
                {
                    os.Close();
                }
                // Record the pack at the start of the pack info list. This
                // way clients are likely to consult the newest pack first,
                // and discover the most recent objects there.
                //
                AList <string> infoPacks = new AList <string>();
                infoPacks.AddItem(packName);
                Sharpen.Collections.AddAll(infoPacks, packNames.Keys);
                dest.WriteInfoPacks(infoPacks);
            }
            catch (IOException err)
            {
                SafeDelete(pathIdx);
                SafeDelete(pathPack);
                throw new TransportException(uri, JGitText.Get().cannotStoreObjects, err);
            }
            finally
            {
                writer.Release();
            }
        }