private async Task <DataflowContext> DownloadFeedAsync(DataflowContext context)
{
try
{
await Retriable.RetryAsync(
async() =>
{
if (File.Exists(context.Destination))
{
context.AlreadyDownloaded = true;
Console.WriteLine("Already Downloaded: " + context.Destination);
return;
}
else
{
var fileInfo = new FileInfo(context.Destination);
if (!fileInfo.Directory.Exists)
{
fileInfo.Directory.Create();
}
}
using (HttpClient client = this.httpClientFactory.CreateClient())
{
var request = new HttpRequestMessage(HttpMethod.Get, context.Source);
HttpResponseMessage response = await client.SendAsync(request).ConfigureAwait(false);
using (Stream streamToReadFrom = await response.Content.ReadAsStreamAsync().ConfigureAwait(false))
{
using (Stream streamToWriteTo = File.Open(context.Destination, FileMode.Create))
{
await streamToReadFrom.CopyToAsync(streamToWriteTo).ConfigureAwait(false);
}
}
Console.WriteLine("Downloaded: " + context.Destination);
response.EnsureSuccessStatusCode();
}
},
CancellationToken.None,
new Backoff(5, TimeSpan.FromSeconds(1)),
new AnyException()).ConfigureAwait(false);
context.IsFaulted = false;
}
catch (Exception ex)
{
context.IsFaulted = true;
context.FaultError = ex.Message;
Console.WriteLine("Error Downloading: " + context.Destination);
}
return(context);
}
public async Task DownloadAsync(List <ContentItem> feed, string outputPath)
{
var downloadFeedBlock = new ActionBlock <DataflowContext>(context => this.DownloadFeedAsync(context), new ExecutionDataflowBlockOptions {
MaxDegreeOfParallelism = Environment.ProcessorCount
});
foreach (var contentItem in feed)
{
foreach (var attachment in contentItem.Content.Attachments)
{
var context = new DataflowContext {
Source = attachment.Url, Destination = Path.GetFullPath(Path.Join(outputPath, attachment.Path))
};
downloadFeedBlock.Post(context);
}
}
downloadFeedBlock.Complete();
await downloadFeedBlock.Completion.ConfigureAwait(false);
Console.WriteLine("File Download Completed");
}