CloudQueue GetQueueReference(AzureQueueAccessInformation accessInfo)
{
var creds = new StorageCredentials(accessInfo.Token);
var uri = new Uri(accessInfo.StorageUri.PrimaryUri);
var client = new CloudQueueClient(uri, creds);
var queue = client.GetQueueReference(accessInfo.QueueName);
return(queue);
}
/// <summary>
/// The MonitorQueue method fetches and processes messages from the queue that is identified by calling GetQueueAccessInformation.
/// It will continue to process messages until ContinueMonitoring returns false.
/// The ProcessMessage delegate is used to process each message, and if the processing fails, the OnError delegate is called.
/// Both ProcessMessage and OnError should return TRUE to indicate that the message should be deleted from the queue.
/// </summary>
public void MonitorQueue()
{
AzureQueueAccessInformation accessInfo = null;
while (ContinueMonitoring == null || ContinueMonitoring())
{
// If we don't have valid queue access information then get some
if (accessInfo == null || DateTime.UtcNow.AddHours(-1) > accessInfo.Expires)
{
try
{
accessInfo = GetQueueAccessInformation();
queue = null;
}
catch (AggregateException ex)
{
// If we have an error handler, then delegate to it
if (OnError != null)
{
OnError(ex.InnerException, null);
}
return; // Abort
}
}
// Get a reference to the Azure queue
if (queue == null)
{
queue = GetQueueReference(accessInfo);
}
// Process the next message
var message = queue.GetMessage();
if (message != null)
{
var delete = ProcessMessage(message);
if (delete)
{
queue.DeleteMessage(message);
}
}
// Wait a little bit before checking the queue again if we didn't
// get a message
if (message == null)
{
Thread.Sleep(1000);
}
}
}
