/// <summary>
/// Throttles the downloads.
/// </summary>
/// <param name="source">Source file.</param>
/// <param name="cancellationToken">A <see cref="CancellationToken"/> to observe while waiting for the task to complete.</param>
/// <returns>A task representing the completion of this function.</returns>
private static async Task Throttle(SourceFile source, CancellationToken cancellationToken)
{
Console.WriteLine("Waiting to download {0}", source.FileName);
await Throttler.WaitAsync();
try
{
await DownloadFile(source, cancellationToken);
}
finally
{
Throttler.Release();
}
}
/// <summary>
/// Downloads a single file.
/// </summary>
/// <param name="source">Source file.</param>
/// <param name="cancellationToken">A <see cref="CancellationToken"/> to observe while waiting for the task to complete.</param>
/// <returns>A task representing the completion of this function.</returns>
private static async Task DownloadFile(SourceFile source, CancellationToken cancellationToken)
{
var path = Path.Combine(Program.Options.DownloadPath, source.FileName);
Console.WriteLine("Downloading {0}", path);
using (var client = new HttpClient())
{
using (var output = new FileStream(path, FileMode.Create, FileAccess.Write, FileShare.None))
using (var stream = await client.GetStreamAsync(source.Uri))
{
await stream.CopyToAsync(output);
}
}
Console.WriteLine("Completed {0}", path);
}
/// <summary>
/// Retries the downloads.
/// </summary>
/// <param name="source">Source file.</param>
/// <param name="cancellationToken">A <see cref="CancellationToken"/> to observe while waiting for the task to complete.</param>
/// <returns>A task representing the completion of this function.</returns>
private static async Task Retry(SourceFile source, CancellationToken cancellationToken)
{
while (!cancellationToken.IsCancellationRequested)
{
try
{
await Throttle(source, cancellationToken);
return;
}
catch (Exception ex)
{
Console.WriteLine(ex.Message);
}
}
}