public async Task <AuxiliaryFileResult <PopularityTransferData> > ReadLatestIndexedAsync(
IAccessCondition accessCondition,
StringCache stringCache)
{
var stopwatch = Stopwatch.StartNew();
var blobName = GetLatestIndexedBlobName();
var blobReference = Container.GetBlobReference(blobName);
_logger.LogInformation("Reading the latest indexed popularity transfers from {BlobName}.", blobName);
bool modified;
var data = new PopularityTransferData();
AuxiliaryFileMetadata metadata;
try
{
using (var stream = await blobReference.OpenReadAsync(accessCondition))
{
ReadStream(stream, (from, to) => data.AddTransfer(stringCache.Dedupe(from), stringCache.Dedupe(to)));
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;
data = null;
metadata = null;
}
stopwatch.Stop();
_telemetryService.TrackReadLatestIndexedPopularityTransfers(data?.Count, modified, stopwatch.Elapsed);
return(new AuxiliaryFileResult <PopularityTransferData>(
modified,
data,
metadata));
}