/// <summary>
/// Dequeue an item from the queue. The queue is single consumer, DequeueAsync must not be called again until the previous dequeue operation have completed.
/// Warning: The returned IFutureItem must not be awaited more than once.
/// </summary>
/// <returns>A future of the dequeued item.</returns>
public IFutureItem DequeueAsync()
{
FutureItem futureItem = new FutureItem();
lock (_queue)
{
if (_pendingDequeue != null)
{
throw new InvalidOperationException("Dequeue operation is already in progress. This queue is single consumer.");
}
if (_isDisposed)
{
futureItem.SetCanceled();
}
else if (_queue.Count > 0)
{
T value = _queue.Dequeue();
futureItem.SetItem(value);
}
else if (_addingCompleted)
{
futureItem.SetCanceled();
}
else
{
_pendingDequeue = futureItem;
}
}
return(futureItem);
}
/// <summary>
/// Add an item to the queue. Can be called concurrently.
/// </summary>
/// <returns>True if the item was enqueued, otherwise False.</returns>
public bool Enqueue(T item)
{
FutureItem completedWaiter = null;
lock (_queue)
{
if (_addingCompleted)
{
return(false);
}
if (_pendingDequeue != null)
{
completedWaiter = _pendingDequeue;
_pendingDequeue = null;
}
else
{
_queue.Enqueue(item);
}
}
completedWaiter?.SetItem(item, _dispatcher);
return(true);
}
public async Task <FutureItemDto> Handle(CreateUserFutureItemCommand request, CancellationToken cancellationToken)
{
var user = await _userRepository.GetUserDetailsAsync(request.UserId);
var futureItem = new FutureItem(Guid.NewGuid(), request.Name, request.StorageUri, request.ItemType, request.IsActive);
user.CreateFutureItem(futureItem);
var result = await _userRepository.CommitAsync();
return(new FutureItemDto
{
Id = futureItem.Id,
Name = futureItem.Name,
ItemType = futureItem.ItemType,
StorageUri = futureItem.StorageUri,
IsActive = request.IsActive
});
}
public void CreateFutureItem(FutureItem item)
{
_futureItems.Add(item);
}