Renci.SshNet.SftpClient.InternalUploadFile C# (CSharp) Method

        private void InternalUploadFile(Stream input, string path, Flags flags, SftpUploadAsyncResult asyncResult, Action<ulong> uploadCallback)
        {
            if (input == null)
                throw new ArgumentNullException("input");

            if (path.IsNullOrWhiteSpace())
                throw new ArgumentException("path");

            if (_sftpSession == null)
                throw new SshConnectionException("Client not connected.");

            var fullPath = _sftpSession.GetCanonicalPath(path);

            var handle = _sftpSession.RequestOpen(fullPath, flags);

            ulong offset = 0;

            // create buffer of optimal length
            var buffer = new byte[_sftpSession.CalculateOptimalWriteLength(_bufferSize, handle)];

            var bytesRead = input.Read(buffer, 0, buffer.Length);
            var expectedResponses = 0;
            var responseReceivedWaitHandle = new AutoResetEvent(false);

            do
            {
                //  Cancel upload
                if (asyncResult != null && asyncResult.IsUploadCanceled)
                    break;

                if (bytesRead > 0)
                {
                    var writtenBytes = offset + (ulong) bytesRead;

                    _sftpSession.RequestWrite(handle, offset, buffer, 0, bytesRead, null, s =>
                        {
                            if (s.StatusCode == StatusCodes.Ok)
                            {
                                Interlocked.Decrement(ref expectedResponses);
                                responseReceivedWaitHandle.Set();

                                //  Call callback to report number of bytes written
                                if (uploadCallback != null)
                                {
                                    //  Execute callback on different thread
                                    ThreadAbstraction.ExecuteThread(() => uploadCallback(writtenBytes));
                                }
                            }
                        });
                    Interlocked.Increment(ref expectedResponses);

                    offset += (ulong) bytesRead;

                    bytesRead = input.Read(buffer, 0, buffer.Length);
                }
                else if (expectedResponses > 0)
                {
                    //  Wait for expectedResponses to change
                    _sftpSession.WaitOnHandle(responseReceivedWaitHandle, OperationTimeout);
                }
            } while (expectedResponses > 0 || bytesRead > 0);

            _sftpSession.RequestClose(handle);
        }