public static async Task <Tuple <IEnumerable <IStorageBlob>, DateTime> > PollNewBlobsAsync(
IStorageBlobContainer container, DateTime previousTimestamp, CancellationToken cancellationToken)
{
DateTime updatedTimestamp = previousTimestamp;
IList <IStorageListBlobItem> currentBlobs;
try
{
currentBlobs = (await container.ListBlobsAsync(prefix: null, useFlatBlobListing: true,
cancellationToken: cancellationToken)).ToList();
}
catch (StorageException exception)
{
if (exception.IsNotFound())
{
return(new Tuple <IEnumerable <IStorageBlob>, DateTime>(
Enumerable.Empty <IStorageBlob>(), updatedTimestamp));
}
else
{
throw;
}
}
List <IStorageBlob> newBlobs = new List <IStorageBlob>();
// Type cast to IStorageBlob is safe due to useFlatBlobListing: true above.
foreach (IStorageBlob currentBlob in currentBlobs)
{
cancellationToken.ThrowIfCancellationRequested();
IStorageBlobProperties properties = currentBlob.Properties;
DateTime lastModifiedTimestamp = properties.LastModified.Value.UtcDateTime;
if (lastModifiedTimestamp > updatedTimestamp)
{
updatedTimestamp = lastModifiedTimestamp;
}
if (lastModifiedTimestamp > previousTimestamp)
{
newBlobs.Add(currentBlob);
}
}
return(new Tuple <IEnumerable <IStorageBlob>, DateTime>(newBlobs, updatedTimestamp));
}
public static async Task<Tuple<IEnumerable<IStorageBlob>, DateTime>> PollNewBlobsAsync(
IStorageBlobContainer container, DateTime previousTimestamp, CancellationToken cancellationToken)
{
DateTime updatedTimestamp = previousTimestamp;
IList<IStorageListBlobItem> currentBlobs;
try
{
currentBlobs = (await container.ListBlobsAsync(prefix: null, useFlatBlobListing: true,
cancellationToken: cancellationToken)).ToList();
}
catch (StorageException exception)
{
if (exception.IsNotFound())
{
return new Tuple<IEnumerable<IStorageBlob>, DateTime>(
Enumerable.Empty<IStorageBlob>(), updatedTimestamp);
}
else
{
throw;
}
}
List<IStorageBlob> newBlobs = new List<IStorageBlob>();
// Type cast to IStorageBlob is safe due to useFlatBlobListing: true above.
foreach (IStorageBlob currentBlob in currentBlobs)
{
cancellationToken.ThrowIfCancellationRequested();
try
{
await currentBlob.FetchAttributesAsync(cancellationToken);
}
catch (StorageException exception)
{
if (exception.IsNotFound())
{
continue;
}
else
{
throw;
}
}
IStorageBlobProperties properties = currentBlob.Properties;
DateTime lastModifiedTimestamp = properties.LastModified.Value.UtcDateTime;
if (lastModifiedTimestamp > updatedTimestamp)
{
updatedTimestamp = lastModifiedTimestamp;
}
if (lastModifiedTimestamp > previousTimestamp)
{
newBlobs.Add(currentBlob);
}
}
return new Tuple<IEnumerable<IStorageBlob>, DateTime>(newBlobs, updatedTimestamp);
}