public static IQueueSource <T> Where <T>(this IQueueSource <T> queue, Func <T, Task <bool> > predicate, int?capacity = null)
{
AsyncQueue <T> outQueue = new AsyncQueue <T>(capacity ?? 2);
Func <Task> worker = async delegate {
while (true)
{
Option <T> item = await queue.Dequeue(CancellationToken.None);
if (!item.HasValue)
{
break;
}
if (await predicate(item.Value))
{
await outQueue.Enqueue(item.Value, CancellationToken.None);
}
}
outQueue.WriteEof();
};
Task _dummy = Task.Run(worker);
return(outQueue);
}
public static IQueueSource <U> Select <T, U>(this IQueueSource <T> queue, Func <T, Task <U> > func, int?capacity = null)
{
AsyncQueue <U> outQueue = new AsyncQueue <U>(capacity ?? 2);
Func <Task> worker = async delegate {
while (true)
{
Option <T> item = await queue.Dequeue(CancellationToken.None);
if (!item.HasValue)
{
break;
}
U item2 = await func(item.Value);
await outQueue.Enqueue(item2, CancellationToken.None);
}
outQueue.WriteEof();
};
Task.Run(worker);
return(outQueue);
}
public static Func <Task> ParallelForEach <T>(IQueueSource <T> source, ParallelWorker parallelWorker, Func <ForEachInfo <T>, Task> processAsync, Func <Task> onCloseAsync, ExceptionCollector ec)
{
Func <Task> t = async delegate()
{
IdleDetector idleDetector = new IdleDetector();
try
{
while (true)
{
var item = await source.Dequeue(ec.CancellationToken);
if (!item.HasValue)
{
break;
}
T itemValue = item.Value;
idleDetector.Enter();
await parallelWorker.StartWorkItem
(
async workerId =>
{
try
{
await processAsync(new ForEachInfo <T>(itemValue, 0, workerId, ec.CancellationToken));
}
catch (Exception exc)
{
ec.Add(exc);
}
finally
{
idleDetector.Leave();
}
},
ec.CancellationToken
);
}
}
finally
{
await idleDetector.WaitForIdle(CancellationToken.None);
if (onCloseAsync != null)
{
try
{
await onCloseAsync();
}
catch (Exception exc)
{
ec.Add(exc);
}
}
}
};
return(t);
}
public static IQueueSource <T> ParallelWhere <T>(this IQueueSource <T> queue, ParallelWorker parallelWorker, Func <T, Task <bool> > predicate, int?capacity = null)
{
AsyncQueue <T> outQueue = new AsyncQueue <T>(capacity ?? 2);
IdleDetector idleDetector = new IdleDetector();
Func <Task> workPoster = async delegate()
{
while (true)
{
Option <T> item = await queue.Dequeue(CancellationToken.None);
if (!item.HasValue)
{
break;
}
T itemValue = item.Value;
idleDetector.Enter();
Task doingWork = await parallelWorker.StartWorkItem
(
async (int workerId) =>
{
try
{
if (await predicate(itemValue))
{
await outQueue.Enqueue(itemValue, CancellationToken.None);
}
}
finally
{
idleDetector.Leave();
}
},
CancellationToken.None
);
}
await idleDetector.WaitForIdle(CancellationToken.None);
outQueue.WriteEof();
};
Task.Run(workPoster);
return(outQueue);
}
public static IEnumerable <T> AsEnumerable <T>(this IQueueSource <T> queue)
{
BlockingCollection <T> bc = new BlockingCollection <T>();
Func <Task> feed = async delegate()
{
while (true)
{
Option <T> item = await queue.Dequeue(CancellationToken.None);
if (item.HasValue)
{
bc.Add(item.Value);
}
else
{
break;
}
}
bc.CompleteAdding();
};
Task _dummy = Task.Run(feed);
while (true)
{
T item2 = default(T);
bool success = false;
try
{
item2 = bc.Take();
success = true;
}
catch (InvalidOperationException exc)
{
// BlockingCollection ran out of items
System.Diagnostics.Debug.WriteLine(exc);
}
if (!success)
{
break;
}
yield return(item2);
}
}
public static Func <Task> ForEach <T>(IQueueSource <T> source, Func <ForEachInfo <T>, Task> processAsync, Func <Task> onCloseAsync, ExceptionCollector ec)
{
Func <Task> t = async delegate()
{
try
{
while (true)
{
var item = await source.Dequeue(ec.CancellationToken);
if (!item.HasValue)
{
break;
}
try
{
await processAsync(new ForEachInfo <T>(item.Value, 0, 0, ec.CancellationToken));
}
catch (Exception exc)
{
ec.Add(exc);
break;
}
}
}
finally
{
if (onCloseAsync != null)
{
try
{
await onCloseAsync();
}
catch (Exception exc)
{
ec.Add(exc);
}
}
}
};
return(t);
}
public static IQueueSource <T> Reorder <T>(this IQueueSource <T> queue, Func <T, int> getOrder, int first, int?capacity = null)
{
AsyncQueue <T> outQueue = new AsyncQueue <T>(capacity ?? 2);
Func <Task> worker = async delegate {
int next = first;
ImmutableDictionary <int, T> buffer = ImmutableDictionary <int, T> .Empty;
while (true)
{
Option <T> item = await queue.Dequeue(CancellationToken.None);
if (!item.HasValue)
{
break;
}
int order = getOrder(item.Value);
if (order == next)
{
await outQueue.Enqueue(item.Value, CancellationToken.None);
++next;
while (buffer.ContainsKey(next))
{
await outQueue.Enqueue(buffer[next], CancellationToken.None);
buffer = buffer.Remove(next);
++next;
}
}
else
{
buffer = buffer.Add(order, item.Value);
}
}
outQueue.WriteEof();
};
Task.Run(worker);
return(outQueue);
}
