public async Task <AuxiliaryFileResult <DownloadData> > ReadLatestIndexedAsync(
IAccessCondition accessCondition,
StringCache stringCache)
{
var stopwatch = Stopwatch.StartNew();
var blobName = GetLatestIndexedBlobName();
var blobReference = Container.GetBlobReference(blobName);
_logger.LogInformation("Reading the latest indexed downloads from {BlobName}.", blobName);
bool modified;
var downloads = new DownloadData();
AuxiliaryFileMetadata metadata;
try
{
using (var stream = await blobReference.OpenReadAsync(accessCondition))
{
ReadStream(
stream,
(id, version, downloadCount) =>
{
id = stringCache.Dedupe(id);
version = stringCache.Dedupe(version);
downloads.SetDownloadCount(id, version, downloadCount);
});
modified = true;
metadata = new AuxiliaryFileMetadata(
lastModified: new DateTimeOffset(blobReference.LastModifiedUtc, TimeSpan.Zero),
loadDuration: stopwatch.Elapsed,
fileSize: blobReference.Properties.Length,
etag: blobReference.ETag);
}
}
catch (StorageException ex) when(ex.RequestInformation.HttpStatusCode == (int)HttpStatusCode.NotModified)
{
_logger.LogInformation("The blob {BlobName} has not changed.", blobName);
modified = false;
downloads = null;
metadata = null;
}
stopwatch.Stop();
_telemetryService.TrackReadLatestIndexedDownloads(downloads?.Count, modified, stopwatch.Elapsed);
return(new AuxiliaryFileResult <DownloadData>(
modified,
downloads,
metadata));
}