/// <summary>
/// Invoked upon a remote request to download a file.
/// </summary>
/// <param name="username">The username of the requesting user.</param>
/// <param name="endpoint">The IP endpoint of the requesting user.</param>
/// <param name="filename">The filename of the requested file.</param>
/// <param name="tracker">(for example purposes) the ITransferTracker used to track progress.</param>
/// <returns>A Task representing the asynchronous operation.</returns>
/// <exception cref="DownloadEnqueueException">Thrown when the download is rejected. The Exception message will be passed to the remote user.</exception>
/// <exception cref="Exception">Thrown on any other Exception other than a rejection. A generic message will be passed to the remote user for security reasons.</exception>
private Task EnqueueDownloadAction(string username, IPEndPoint endpoint, string filename, ITransferTracker tracker)
{
filename = filename.ToLocalOSPath();
var fileInfo = new FileInfo(filename);
if (!fileInfo.Exists)
{
Console.WriteLine($"[UPLOAD REJECTED] File {filename} not found.");
throw new DownloadEnqueueException($"File not found.");
}
// create a new cancellation token source so that we can cancel the upload from the UI.
var cts = new CancellationTokenSource();
var topts = new TransferOptions(stateChanged: (e) => tracker.AddOrUpdate(e, cts), progressUpdated: (e) => tracker.AddOrUpdate(e, cts));
// accept all download requests, and begin the upload immediately.
// normally there would be an internal queue, and uploads would be handled separately.
Task.Run(async() =>
{
using (var stream = new FileStream(fileInfo.FullName, FileMode.Open))
{
await Client.UploadAsync(username, fileInfo.FullName, fileInfo.Length, stream, options: topts, cancellationToken: cts.Token);
}
}).ContinueWith(t =>
{
Console.WriteLine($"[UPLOAD FAILED] {t.Exception}");
}, TaskContinuationOptions.NotOnRanToCompletion); // fire and forget
// return a completed task so that the invoking code can respond to the remote client.
return(Task.CompletedTask);
}
/// <summary>
/// Invoked upon a remote request to download a file.
/// </summary>
/// <param name="username">The username of the requesting user.</param>
/// <param name="endpoint">The IP endpoint of the requesting user.</param>
/// <param name="filename">The filename of the requested file.</param>
/// <param name="tracker">(for example purposes) the ITransferTracker used to track progress.</param>
/// <returns>A Task representing the asynchronous operation.</returns>
/// <exception cref="DownloadEnqueueException">Thrown when the download is rejected. The Exception message will be passed to the remote user.</exception>
/// <exception cref="Exception">Thrown on any other Exception other than a rejection. A generic message will be passed to the remote user for security reasons.</exception>
private Task EnqueueDownloadAction(string username, IPEndPoint endpoint, string filename, ITransferTracker tracker)
{
_ = endpoint;
filename = filename.ToLocalOSPath();
var fileInfo = new FileInfo(filename);
if (!fileInfo.Exists)
{
Console.WriteLine($"[UPLOAD REJECTED] File {filename} not found.");
throw new DownloadEnqueueException($"File not found.");
}
if (tracker.TryGet(TransferDirection.Upload, username, filename, out _))
{
// in this case, a re-requested file is a no-op. normally we'd want to respond with a
// PlaceInQueueResponse
Console.WriteLine($"[UPLOAD RE-REQUESTED] [{username}/{filename}]");
return(Task.CompletedTask);
}
// create a new cancellation token source so that we can cancel the upload from the UI.
var cts = new CancellationTokenSource();
var topts = new TransferOptions(stateChanged: (e) => tracker.AddOrUpdate(e, cts), progressUpdated: (e) => tracker.AddOrUpdate(e, cts), governor: (t, c) => Task.Delay(1, c));
// accept all download requests, and begin the upload immediately.
// normally there would be an internal queue, and uploads would be handled separately.
Task.Run(async() =>
{
using var stream = new FileStream(fileInfo.FullName, FileMode.Open, FileAccess.Read);
await Client.UploadAsync(username, fileInfo.FullName, fileInfo.Length, stream, options: topts, cancellationToken: cts.Token);
}).ContinueWith(t =>
{
Console.WriteLine($"[UPLOAD FAILED] {t.Exception}");
}, TaskContinuationOptions.NotOnRanToCompletion); // fire and forget
// return a completed task so that the invoking code can respond to the remote client.
return(Task.CompletedTask);
}