public static IEnumerable <T> ConstantThreadedBuffer <T>(this IEnumerable <T> seq, int maxBatches, int batchSize)
{
BatchBlockingCollection <T> buffer = new BatchBlockingCollection <T>(maxBatches, batchSize);
CancellationTokenSource cancel = new CancellationTokenSource();
var runner = Task.Run(() =>
{
foreach (var t in seq)
{
if (cancel.IsCancellationRequested)
{
break;
}
buffer.Add(t, cancel.Token);
}
buffer.Complete();
});
void cancelAndWait()
{
cancel.Cancel();
runner.Wait();
}
using (new DisposeAction(cancelAndWait))
{
foreach (var t in buffer)
{
yield return(t);
}
}
}
public static IEnumerable <T> TaskedThreadedBuffer <T>(this IEnumerable <T> seq, int maxBatches, int batchSize)
{
BatchBlockingCollection <T> buffer = new BatchBlockingCollection <T>(batchSize);
Task readerTask = null;
bool completed = false;
var en = seq.GetEnumerator();
CancellationTokenSource cancel = new CancellationTokenSource();
Exception e = null;
Action runReader = () =>
{
if (readerTask != null)
{
readerTask.GetAwaiter().GetResult();
}
if (completed)
{
return;
}
readerTask = Task.Run(() =>
{
while (buffer.BatchCount < maxBatches)
{
if (cancel.IsCancellationRequested)
{
break;
}
try
{
if (!en.MoveNext())
{
completed = true;
buffer.Complete();
return;
}
buffer.Add(en.Current, cancel.Token);
}
catch (Exception ex)
{
buffer.Complete();
cancel.Cancel();
e = ex;
}
}
readerTask = null;
});
};
runReader();
void cancelAndWait()
{
cancel.Cancel();
buffer.Complete();
readerTask?.Wait();
}
using (new DisposeAction(cancelAndWait))
{
foreach (var t in buffer)
{
yield return(t);
if (buffer.BatchCount < maxBatches / 2 || buffer.BatchCount == 0)
{
if (!completed)
{
runReader();
}
}
}
if (e != null)
{
throw e;
}
}
}