private TransformBlock <PipelineItem <TItem>, PipelineItem <TItem> > BuildProcessingBlock <TItem>(
PipelineBlock <TItem> block,
PipelineTaskStep <TItem> step,
DataflowExecutionContext context,
CancellationToken cancellation)
{
return(new TransformBlock <PipelineItem <TItem>, PipelineItem <TItem> >(
x =>
{
if (x == null)
{
return x;
}
context.Events?.Raise(e => e.OnBlockStarted(block, x.Number, x.Item, step, context.StepContext.Task));
var sw = Stopwatch.StartNew();
try
{
block.Body(x.Item);
}
catch (Exception e)
{
throw new TaskExecutionException(e, step, block.GetExceptionData(x.Number));
}
sw.Stop();
context.TotalBlockDurations.AddOrUpdate(block.Name, sw.Elapsed, (_, duration) => duration + sw.Elapsed);
context.Events?.Raise(e => e.OnBlockEnded(block, x.Number, x.Item, step, context.StepContext.Task, sw.Elapsed));
return x;
},
new ExecutionDataflowBlockOptions
{
NameFormat = block.Name,
MaxDegreeOfParallelism = block.MaxDegreeOfParallelism,
BoundedCapacity = block.MaxDegreeOfParallelism,
EnsureOrdered = true,
CancellationToken = cancellation
}));
}
