/// <summary>Initializes a new instance of the <see cref="StoragePageBlob"/> class.</summary>
/// <param name="parent">The parent blob container.</param>
/// <param name="sdk">The SDK blob to wrap.</param>
public StoragePageBlob(IStorageBlobContainer parent, CloudPageBlob sdk)
{
_parent = parent;
_sdk = sdk;
_properties = new StorageBlobProperties(sdk);
}
/// <summary>Initializes a new instance of the <see cref="StorageBlockBlob"/> class.</summary>
/// <param name="parent">The parent blob container.</param>
/// <param name="sdk">The SDK blob to wrap.</param>
public StorageBlockBlob(IStorageBlobContainer parent, CloudBlockBlob sdk)
{
_parent = parent;
_sdk = sdk;
_properties = new StorageBlobProperties(sdk);
}
/// <summary>
/// This method is called each polling interval for all containers. The method divides the
/// budget of allocated number of blobs to query, for each container we query a page of
/// that size and we keep the continuation token for the next time. AS a curser, we use
/// the time stamp when the current cycle on the container started. blobs newer than that
/// time will be considered new and registrations will be notified
/// </summary>
/// <param name="container"></param>
/// <param name="containerScanInfo"> Information that includes the last cycle start
/// the continuation token and the current cycle start for a container</param>
/// <param name="cancellationToken"></param>
/// <returns></returns>
public async Task <IEnumerable <IStorageBlob> > PollNewBlobsAsync(
IStorageBlobContainer container, ContainerScanInfo containerScanInfo, CancellationToken cancellationToken)
{
IEnumerable <IStorageListBlobItem> currentBlobs;
IStorageBlobResultSegment blobSegment;
int blobPollLimitPerContainer = _scanBlobLimitPerPoll / _scanInfo.Count;
BlobContinuationToken continuationToken = containerScanInfo.ContinuationToken;
// if starting the cycle, reset the sweep time
if (continuationToken == null)
{
containerScanInfo.CurrentSweepCycleLatestModified = DateTime.MinValue;
}
try
{
blobSegment = await container.ListBlobsSegmentedAsync(prefix : null, useFlatBlobListing : true,
blobListingDetails : BlobListingDetails.None, maxResults : blobPollLimitPerContainer, currentToken : continuationToken,
options : null, operationContext : null, cancellationToken : cancellationToken);
currentBlobs = blobSegment.Results;
}
catch (StorageException exception)
{
if (exception.IsNotFound())
{
return(Enumerable.Empty <IStorageBlob>());
}
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 > containerScanInfo.CurrentSweepCycleLatestModified)
{
containerScanInfo.CurrentSweepCycleLatestModified = lastModifiedTimestamp;
}
if (lastModifiedTimestamp > containerScanInfo.LastSweepCycleLatestModified)
{
newBlobs.Add(currentBlob);
}
}
// record continuation token for next chunk retrieval
containerScanInfo.ContinuationToken = blobSegment.ContinuationToken;
// if ending a cycle then copy currentSweepCycleStartTime to lastSweepCycleStartTime, if changed
if (blobSegment.ContinuationToken == null &&
containerScanInfo.CurrentSweepCycleLatestModified > containerScanInfo.LastSweepCycleLatestModified)
{
containerScanInfo.LastSweepCycleLatestModified = containerScanInfo.CurrentSweepCycleLatestModified;
}
return(newBlobs);
}
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));
}
