//******************************************************************************************************//  ITFtpTransfer.cs - Gbtc////  Copyright © 2020, Grid Protection Alliance.  All Rights Reserved.////  Licensed to the Grid Protection Alliance (GPA) under one or more contributor license agreements. See//  the NOTICE file distributed with this work for additional information regarding copyright ownership.//  The GPA licenses this file to you under the MIT License (MIT), the "License"; you may not use this//  file except in compliance with the License. You may obtain a copy of the License at:////      http://opensource.org/licenses/MIT////  Unless agreed to in writing, the subject software distributed under the License is distributed on an//  "AS-IS" BASIS, WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied. Refer to the//  License for the specific language governing permissions and limitations.////  Code Modification History://  ----------------------------------------------------------------------------------------------------//  05/12/2020 - J. Ritchie Carroll//       Generated original version of source code.////****************************************************************************************************** #region [ Contributor License Agreements ] //*******************************************************************************************************////   Code based on the following project://        https://github.com/Callisto82/tftp.net//  //   Copyright © 2011, Michael Baer////******************************************************************************************************* #endregion using System;using System.IO; // ReSharper disable InconsistentNamingnamespace GSF.Net.TFtp{    public delegate void TFtpEventHandler(ITFtpTransfer transfer);    public delegate void TFtpProgressHandler(ITFtpTransfer transfer, TFtpTransferProgress progress);    public delegate void TFtpErrorHandler(ITFtpTransfer transfer, TFtpTransferError error);     public enum TFtpTransferMode    {        ascii,        octet,        mail    }     /// <summary>    /// Represents a single data transfer between a TFTP server and client.    /// </summary>    public interface ITFtpTransfer : IDisposable    {        /// <summary>        /// Event that is being called while data is being transferred.        /// </summary>        event TFtpProgressHandler OnProgress;         /// <summary>        /// Event that will be called once the data transfer is finished.        /// </summary>        event TFtpEventHandler OnFinished;          /// <summary>        /// Event that will be called if there is an error during the data transfer.        /// Currently, this will return instances of ErrorFromRemoteEndpoint or NetworkError.        /// </summary>        event TFtpErrorHandler OnError;         /// <summary>        /// Requested TFTP transfer mode. For outgoing transfers, this member may be used to set the transfer mode.        /// </summary>        TFtpTransferMode TransferMode { get; set; }         /// <summary>        /// Transfer block size. Set this member to control the TFTP block size option (RFC 2349).        /// </summary>        int BlockSize { get; set; }         /// <summary>        /// Timeout after which commands are sent again.        /// This member is also transmitted as the TFTP timeout interval option (RFC 2349).        /// </summary>        TimeSpan RetryTimeout { get; set; }         /// <summary>        /// Number of times that a RetryTimeout may occur before the transfer is cancelled with a TimeoutError.        /// </summary>        int RetryCount { get; set; }         /// <summary>        /// TFTP can transfer up to 65535 blocks. After that, the block counter wraps to either zero or one, depending on the expectations of the client.        /// </summary>        BlockCounterWrapAround BlockCounterWrapping { get; set; }         /// <summary>        /// Expected transfer size in bytes. 0 if size is unknown.        /// </summary>        long ExpectedSize { get; set; }         /// <summary>        /// Filename for the transferred file.        /// </summary>        string Filename { get; }         /// <summary>        /// You can set your own object here to associate custom data with this transfer.        /// </summary>        object UserContext { get; set; }         /// <summary>        /// Call this function to start the transfer.        /// </summary>        /// <param name="data">The stream from which data is either read (when sending) or written to (when receiving).</param>        void Start(Stream data);         /// <summary>        /// Cancel the currently running transfer, possibly sending the provided reason to the remote endpoint.        /// </summary>        void Cancel(TFtpErrorPacket reason);    }}