public BatchSubscriber(
EventConsumerGrain grain,
IEventDataFormatter eventDataFormatter,
IEventConsumer eventConsumer,
Func <IEventSubscriber, IEventSubscription> factory,
TaskScheduler scheduler)
{
this.eventDataFormatter = eventDataFormatter;
var batchSize = Math.Max(1, eventConsumer !.BatchSize);
var batchDelay = Math.Max(100, eventConsumer.BatchDelay);
var parse = new TransformBlock <Job, Job>(job =>
{
if (job.StoredEvent != null)
{
job.ShouldHandle = eventConsumer.Handles(job.StoredEvent);
}
if (job.ShouldHandle)
{
try
{
job.Event = ParseKnownEvent(job.StoredEvent !);
}
catch (Exception ex)
{
job.Exception = ex;
}
}
return(job);
}, new ExecutionDataflowBlockOptions
{
BoundedCapacity = batchSize,
MaxDegreeOfParallelism = 1,
MaxMessagesPerTask = 1
});
var buffer = AsyncHelper.CreateBatchBlock <Job>(batchSize, batchDelay, new GroupingDataflowBlockOptions
{
BoundedCapacity = batchSize * 2
});
var handle = new ActionBlock <IList <Job> >(async jobs =>
{
foreach (var jobsBySender in jobs.GroupBy <Job, object>(x => x.Sender))
{
var sender = jobsBySender.Key;
if (ReferenceEquals(sender, eventSubscription.Sender))
{
var exception = jobs.FirstOrDefault(x => x.Exception != null)?.Exception;
if (exception != null)
{
await grain.OnErrorAsync(Sender, exception);
}
else
{
await grain.OnEventsAsync(Sender, GetEvents(jobsBySender), GetPosition(jobsBySender));
}
}
}
},
new ExecutionDataflowBlockOptions
{
BoundedCapacity = 2,
MaxDegreeOfParallelism = 1,
MaxMessagesPerTask = 1,
TaskScheduler = scheduler
});
parse.LinkTo(buffer, new DataflowLinkOptions
{
PropagateCompletion = true
});
buffer.LinkTo(handle, new DataflowLinkOptions
{
PropagateCompletion = true
});
pipelineStart = parse;
pipelineEnd = handle;
eventSubscription = factory(this);
}