public async Task TestSlowConsumer()
{
var stopwatch = Stopwatch.StartNew();
void Log(string message)
{
Debug.WriteLine($"[{stopwatch.ElapsedMilliseconds:D3}ms] {message}", nameof(TestSlowConsumer));
}
IPropagatorBlock <int, int> CreateDelayBlock(int delay, int multiplier)
{
return(new TransformBlock <int, int>(
async x =>
{
Log("Delay Enter " + x);
await Task.Delay(delay);
Log("Delay Return " + x);
return x * multiplier;
},
new ExecutionDataflowBlockOptions()
{
BoundedCapacity = 1,
SingleProducerConstrained = true,
}));
}
var sourceBlock = new BufferBlock <int>();
var block1 = CreateDelayBlock(100, 1);
var block2 = CreateDelayBlock(150, 10);
var testBlock = FluentDataflow.Merge(new ISourceBlock <int>[] { block1, block2 });
var consumer = new TransformBlock <int, int>(
async x =>
{
Log("Consumer Enter " + x);
await Task.Delay(50);
Log("Consumer Return " + x);
return(x);
},
new ExecutionDataflowBlockOptions()
{
BoundedCapacity = 1
}
);
sourceBlock.LinkWithCompletion(block1);
sourceBlock.LinkWithCompletion(block2);
testBlock.LinkWithCompletion(consumer);
sourceBlock.Post(1); // to block1
sourceBlock.Post(2); // to block2
sourceBlock.Post(3); // to block1
sourceBlock.Post(4); // to block2
sourceBlock.Complete();
var timeoutToken = TestUtils.CancelAfter(new TimeSpan(2 * TimeSpan.TicksPerSecond));
(await consumer.AsAsyncEnumerable().ToArrayAsync(timeoutToken))
.Is(1, 20, 3, 40);
}