public Dataflow([NotNull] ITargetBlock <TInput> startingBlock, [NotNull] IDataflowBlock finalBlock)
{
if (startingBlock == null)
{
throw new ArgumentNullException(nameof(startingBlock));
}
if (finalBlock == null)
{
throw new ArgumentNullException(nameof(finalBlock));
}
if (finalBlock.GetType().GetInterfaces().Any(type => type.IsGenericType &&
type.GetGenericTypeDefinition() == typeof(ISourceBlock <>)))
{
throw new ArgumentException(string.Format("Dataflow can not have final block of type {0} " +
"because it can not be awaited after completition of it's input.",
finalBlock.GetType()),
nameof(finalBlock));
}
this.startingBlock = startingBlock;
this.finalBlock = finalBlock;
this.status = DataflowStatus.NotStarted;
}
/// <summary>
/// Changes the dataflow <see cref="Status" /> to <see cref="DataflowStatus.InProgress" />.
/// </summary>
public void Start()
{
if (this.status != DataflowStatus.NotStarted)
{
throw new InvalidDataflowStatusException(this.status);
}
this.stopwatch = new Stopwatch();
this.stopwatch.Start();
this.status = DataflowStatus.InProgress;
}
/// <summary>
/// Signals the completion of data sending.
/// Returns the task that will be completed when remaining data in dataflow is processed.
/// </summary>
public async Task CompleteAsync()
{
if (this.status != DataflowStatus.InProgress)
{
throw new InvalidDataflowStatusException(this.status);
}
this.startingBlock.Complete();
this.status = DataflowStatus.AllDataSent;
var completion = this.startingBlock == this.finalBlock
? this.finalBlock.Completion
: Task.WhenAll(this.startingBlock.Completion, this.finalBlock.Completion);
await completion.ConfigureAwait(false);
this.stopwatch.Stop();
this.status = DataflowStatus.Completed;
}
public InvalidDataflowStatusException(DataflowStatus status, Exception innerException = null)
: base(string.Format("Dataflow status is invalid {0} for performing current operation.", status), innerException)
{
this.status = status;
}