private async Task <MemoryStream> DownloadAndCacheAsync(string url, string filename, string filepath, CancellationToken token, TimeSpan?duration)
{
if (duration == null)
{
duration = new TimeSpan(30, 0, 0, 0); // by default we cache data 30 days
}
int headersTimeout = ImageService.Config.HttpHeadersTimeout;
int readTimeout = ImageService.Config.HttpReadTimeout - headersTimeout;
var cancelHeadersToken = new CancellationTokenSource();
cancelHeadersToken.CancelAfter(TimeSpan.FromSeconds(headersTimeout));
var linkedHeadersToken = CancellationTokenSource.CreateLinkedTokenSource(token, cancelHeadersToken.Token);
using (var response = await DownloadHttpClient.GetAsync(url, HttpCompletionOption.ResponseHeadersRead, linkedHeadersToken.Token).ConfigureAwait(false))
{
if (!response.IsSuccessStatusCode || response.Content == null)
{
return(null);
}
var cancelReadToken = new CancellationTokenSource();
cancelReadToken.CancelAfter(TimeSpan.FromSeconds(readTimeout));
var responseBytes = await response.Content.ReadAsByteArrayAsync().ConfigureAwait(false);
var memoryStream = new MemoryStream(responseBytes, false);
memoryStream.Position = 0;
_diskCache.AddToSavingQueueIfNotExists(filename, responseBytes, duration.Value);
return(memoryStream);
}
}
private async Task <MemoryStream> DownloadStreamAndCacheAsync(string url, string filename, string filepath, CancellationToken token, TimeSpan?duration)
{
var responseBytes = await DownloadAsync(url, filename, filepath, token).ConfigureAwait(false);
if (responseBytes == null)
{
return(null);
}
var memoryStream = new MemoryStream(responseBytes, false);
memoryStream.Position = 0;
_diskCache.AddToSavingQueueIfNotExists(filename, responseBytes, duration ?? new TimeSpan(30, 0, 0, 0)); // by default we cache data 30 days)
return(memoryStream);
}
