public async Task DequeueAsync(Func <IQueueItem <T>, Task <bool> > processor)
{
_logger.LogTrace("LargeMessageQueue<T>: DequeueAsync - attempting dequeue");
await _referenceQueue.DequeueAsync(async message =>
{
if (message != null)
{
_logger.LogTrace("LargeMessageQueue<T>: DequeueAsync - dequeued large message with blob reference {BLOBREFERENCE}", message.Item.BlobReference);
IBlob blob;
T item;
try
{
blob = _blobRepository.Get(message.Item.BlobReference);
var serializedObjectText = await blob.DownloadStringAsync(Encoding.UTF8);
await _referenceQueue.ExtendLeaseAsync(message);
item = _serializer.Deserialize <T>(serializedObjectText);
await _referenceQueue.ExtendLeaseAsync(message);
}
catch (Exception ex)
{
_logger.LogTrace("LargeMessageQueue<T>: DequeueAsync - unable to download blob {BLOBREFERENCE}", message.Item.BlobReference);
if (_errorHandler != null)
{
return(await _errorHandler.UnableToDownloadBlobAsync(ex, message));
}
throw new LargeMessageQueueException("Unable to download blob", ex, message);
}
bool result = await processor(new LargeMessageQueueItem <T>(item, message.DequeueCount, message));
if (result)
{
try
{
_logger.LogTrace("LargeMessageQueue<T>: DequeueAsync - deleting blob reference {BLOBREFERENCE}", message.Item.BlobReference);
await _referenceQueue.ExtendLeaseAsync(message);
await blob.DeleteAsync();
}
catch (Exception ex)
{
_logger.LogTrace("LargeMessageQueue<T>: DequeueAsync - unable to delete blob reference {BLOBREFERENCE}", message.Item.BlobReference);
if (_errorHandler != null)
{
return(await _errorHandler.UnableToDeleteBlobAsync(ex, message));
}
throw new LargeMessageQueueException("Unable to delete blob, abandoning queue item", ex, message);
}
}
return(result);
}
return(await processor(null));
});
}
public async Task DequeueAsync(Func <IQueueItem <T>, Task <bool> > processor, TimeSpan?visibilityTimeout)
{
CloudQueueMessage message = await _queue.GetMessageAsync(visibilityTimeout, null, null);
if (message != null)
{
_logger?.LogTrace("AsyncQueue: DequeueAsync - dequeued item from queue {QUEUENAME}", _queueName);
T item = _serializer.Deserialize <T>(message.AsString);
if (await processor(new CloudQueueItem <T>(message, item, message.DequeueCount, message.PopReceipt)))
{
_logger?.LogTrace("AsyncQueue: DequeueAsync - deleting item from queue {QUEUENAME}", _queueName);
await _queue.DeleteMessageAsync(message);
}
else
{
_logger?.LogTrace("AsyncQueue: DequeueAsync - returnng item to queue {QUEUENAME}", _queueName);
}
}
else
{
await processor(null);
}
}