/// <summary>
/// Creates the queue of the name <paramref name="queueName"/> if it does not already exist,
/// the queue is attached to <see cref="DequeuAndProcessCommand"/> using a <see cref="Thread"/>.
/// </summary>
/// <param name="queueName">The name of the queue to check and create.</param>
protected void CreateQueueAndAttachListenerIfNotExist(string queueName)
{
if (!QueueTracker.ContainsKey(queueName))
{
QueueTrackerLock.EnterWriteLock();
try
{
if (!QueueTracker.ContainsKey(queueName))
{
QueueTracker.TryAdd(queueName, new ConcurrentQueue <ICommand <TAuthenticationToken> >());
new Thread(() =>
{
Thread.CurrentThread.Name = queueName;
DequeuAndProcessCommand(queueName);
}).Start();
}
}
catch (Exception exception)
{
Logger.LogError(string.Format("Processing a request to start a thread for the queue '{0}' failed.", queueName), exception: exception);
}
finally
{
QueueTrackerLock.ExitWriteLock();
}
}
}
protected void DequeuAndProcessCommand(string queueName)
{
while (true)
{
try
{
ConcurrentQueue <ICommand <TAuthenticationToken> > queue;
if (QueueTracker.TryGetValue(queueName, out queue))
{
while (!queue.IsEmpty)
{
ICommand <TAuthenticationToken> command;
if (queue.TryDequeue(out command))
{
try
{
CorrelationIdHelper.SetCorrelationId(command.CorrelationId);
}
catch (Exception exception)
{
Logger.LogError(string.Format("Trying to set the CorrelationId from the command type {1} for a request for the queue '{0}' failed.", queueName, command.GetType()), exception: exception);
}
try
{
AuthenticationTokenHelper.SetAuthenticationToken(command.AuthenticationToken);
}
catch (Exception exception)
{
Logger.LogError(string.Format("Trying to set the AuthenticationToken from the command type {1} for a request for the queue '{0}' failed.", queueName, command.GetType()), exception: exception);
}
try
{
ReceiveCommand(command);
}
catch (Exception exception)
{
Logger.LogError(string.Format("Processing the command type {1} for a request for the queue '{0}' failed.", queueName, command.GetType()), exception: exception);
queue.Enqueue(command);
}
}
else
{
Logger.LogDebug(string.Format("Trying to dequeue a command from the queue '{0}' failed.", queueName));
}
}
}
else
{
Logger.LogDebug(string.Format("Trying to find the queue '{0}' failed.", queueName));
}
Thread.Sleep(100);
}
catch (Exception exception)
{
Logger.LogError(string.Format("Dequeuing and processing a request for the queue '{0}' failed.", queueName), exception: exception);
}
}
}
/// <summary>
/// Adds the provided <paramref name="command"/> to the <see cref="QueueTracker"/> of the queue <paramref name="targetQueueName"/>.
/// </summary>
private void EnqueueCommand(string targetQueueName, ICommand <TAuthenticationToken> command)
{
var queue = QueueTracker.GetOrAdd(targetQueueName, new ConcurrentQueue <ICommand <TAuthenticationToken> >());
queue.Enqueue(command);
}
/// <summary>
/// Takes an <see cref="IEvent{TAuthenticationToken}"/> off the queue of <paramref name="queueName"/>
/// and calls <see cref="ReceiveEvent"/>. Repeats in a loop until the queue is empty.
/// </summary>
/// <param name="queueName">The name of the queue process.</param>
protected void DequeuAndProcessEvent(string queueName)
{
SpinWait.SpinUntil
(
() =>
{
try
{
ConcurrentQueue <IEvent <TAuthenticationToken> > queue;
if (QueueTracker.TryGetValue(queueName, out queue))
{
while (!queue.IsEmpty)
{
IEvent <TAuthenticationToken> @event;
if (queue.TryDequeue(out @event))
{
try
{
CorrelationIdHelper.SetCorrelationId(@event.CorrelationId);
}
catch (Exception exception)
{
Logger.LogError(string.Format("Trying to set the CorrelationId from the event type {1} for a request for the queue '{0}' failed.", queueName, @event.GetType()), exception: exception);
}
try
{
AuthenticationTokenHelper.SetAuthenticationToken(@event.AuthenticationToken);
}
catch (Exception exception)
{
Logger.LogError(string.Format("Trying to set the AuthenticationToken from the event type {1} for a request for the queue '{0}' failed.", queueName, @event.GetType()), exception: exception);
}
try
{
ReceiveEvent(@event);
}
catch (Exception exception)
{
Logger.LogError(string.Format("Processing the event type {1} for a request for the queue '{0}' failed.", queueName, @event.GetType()), exception: exception);
queue.Enqueue(@event);
}
}
else
{
Logger.LogDebug(string.Format("Trying to dequeue a event from the queue '{0}' failed.", queueName));
}
}
}
else
{
Logger.LogDebug(string.Format("Trying to find the queue '{0}' failed.", queueName));
}
Thread.Sleep(100);
}
catch (Exception exception)
{
Logger.LogError(string.Format("Dequeuing and processing a request for the queue '{0}' failed.", queueName), exception: exception);
}
// Always return false to keep this spinning.
return(false);
},
sleepInMilliseconds: 1000
);
}
/// <summary>
/// Adds the provided <paramref name="event"/> to the <see cref="QueueTracker"/> of the queue <paramref name="targetQueueName"/>.
/// </summary>
private void EnqueueEvent(string targetQueueName, IEvent <TAuthenticationToken> @event)
{
var queue = QueueTracker.GetOrAdd(targetQueueName, new ConcurrentQueue <IEvent <TAuthenticationToken> >());
queue.Enqueue(@event);
}
