public IAsync Receive(Action <Result> handler)
{
IAsyncSource source = Async.NewSource();
bool flag = false;
object sync = this.sync;
lock (sync)
{
if (this.result != null)
{
flag = true;
}
else
{
if (this.handlers == null)
{
this.handlers = new List <Tuple <Action <Result>, IAsyncSource> >(1);
}
this.handlers.Add(Tuple.Create <Action <Result>, IAsyncSource>(handler, source));
}
}
if (flag)
{
Result result = handler.Try <Result>(this.result);
source.SetResult(result);
}
return(source.AsReceiveOnly());
}
public IAsync Enqueue(QueueSide qSide, Action callback)
{
Validate.Begin().IsNotNull <Action>(callback, "callback").IsTrue(((qSide == QueueSide.Front) || (qSide == QueueSide.Back)), "qSide is not a valid member of the QueueSide enumeration").Check();
IAsyncSource source = Async.NewSource();
if (this.pleaseAbort)
{
source.Throw(new OperationCanceledException("The work queue has shut down."));
}
else
{
object sync = this.Sync;
lock (sync)
{
Action item = delegate {
callback.Try().Into(source);
};
Action action2 = delegate {
source.Throw(new OperationCanceledException("The dispatcher has shut down."));
};
if (qSide == QueueSide.Front)
{
this.runFnQ.EnqueueFront(item);
this.cancelFnQ.EnqueueFront(action2);
}
else
{
this.runFnQ.Enqueue(item);
this.cancelFnQ.Enqueue(action2);
}
ThreadPool.QueueUserWorkItem(this.threadPoolCallback);
}
}
return(source.AsReceiveOnly());
}
public IAsync BeginTry(Action callback)
{
base.VerifyAccess();
IAsyncSource async = Async.NewSource();
this.syncContext.Post(delegate(object _) {
async.SetResult(callback.Try());
});
return(async);
}
public AsyncPump(
[NotNull] IAsyncSource <T> source,
[NotNull] IAsyncTarget <T> target
)
{
if (source == null)
{
throw new ArgumentNullException("source");
}
if (target == null)
{
throw new ArgumentNullException("target");
}
m_source = source;
m_target = target;
}
/// <summary>Pump the content of a source into a list</summary>
public static async Task <List <T> > PumpToListAsync <T>(this IAsyncSource <T> source, CancellationToken ct)
{
if (ct.IsCancellationRequested)
{
ct.ThrowIfCancellationRequested();
}
var buffer = new Buffer <T>();
var target = CreateTarget <T>(
(x, _) => buffer.Add(x)
);
await PumpToAsync <T>(source, target, ct).ConfigureAwait(false);
return(buffer.ToList());
}
public static IAsync <T> BeginEval <T>(this IAsyncWorkQueue queue, Func <T> f)
{
IAsyncSource <T> source = Async.NewSource <T>();
queue.BeginTry(delegate {
try
{
Result <T> result = f.Eval <T>();
source.SetResult(result);
}
catch (Exception exception)
{
source.Throw <T>(new TargetInvocationException(exception));
}
});
return(source.AsReceiveOnly <T>());
}
public IAsync BeginTry(Action callback)
{
IAsyncSource source = Async.NewSource();
this.dispatcher.BeginInvoke(delegate {
try
{
Result @void = Result.Void;
callback();
source.SetResult(@void);
}
catch (Exception exception1)
{
Result result = Result.NewError(exception1);
source.SetResult(result);
}
}, Array.Empty <object>());
return(source.AsReceiveOnly());
}
public static async Task <List <TOutput> > TransformToListAsync <TInput, TOutput>(IAsyncSource <TInput> source, Func <TInput, CancellationToken, Task <TOutput> > transform, CancellationToken ct, int?maxConcurrency = null, TaskScheduler scheduler = null)
{
ct.ThrowIfCancellationRequested();
using (var queue = CreateOrderPreservingAsyncBuffer <TOutput>(maxConcurrency ?? 32))
{
using (var pipe = CreateAsyncTransform <TInput, TOutput>(transform, queue, scheduler))
{
// start the output pump
var output = PumpToListAsync(queue, ct);
// start the intput pump
var input = PumpToAsync(source, pipe, ct);
await Task.WhenAll(input, output).ConfigureAwait(false);
return(output.Result);
}
}
}
/// <summary>Consumes all the elements of the source, and publish them to the target, one by one and in order</summary>
/// <param name="source">Source that produces elements asynchronously</param>
/// <param name="target">Target that consumes elements asynchronously</param>
/// <param name="ct">Cancellation token</param>
/// <returns>Task that completes when all the elements of the source have been published to the target, or fails if on the first error, or the token is cancelled unexpectedly</returns>
/// <remarks>The pump will only read one element at a time, and wait for it to be published to the target, before reading the next element.</remarks>
public static async Task PumpToAsync <T>(this IAsyncSource <T> source, IAsyncTarget <T> target, CancellationToken ct)
{
ct.ThrowIfCancellationRequested();
bool notifiedCompletion = false;
bool notifiedError = false;
try
{
//LogPump("Starting pump");
while (!ct.IsCancellationRequested)
{
//LogPump("Waiting for next");
var current = await source.ReceiveAsync(ct).ConfigureAwait(false);
//LogPump("Received " + (current.HasValue ? "value" : current.Failed ? "error" : "completion") + ", publishing... " + current);
if (ct.IsCancellationRequested)
{
// REVIEW: should we notify the target?
// REVIEW: if the item is IDisposble, who will clean up?
break;
}
// push the data/error/completion on to the target, which will triage and update its state accordingly
await target.Publish(current, ct).ConfigureAwait(false);
if (current.Failed)
{ // bounce the error back to the caller
//REVIEW: SHOULD WE? We poush the error to the target, and the SAME error to the caller... who should be responsible for handling it?
// => target should know about the error (to cancel something)
// => caller should maybe also know that the pump failed unexpectedly....
notifiedError = true;
current.ThrowForNonSuccess(); // throws an exception right here
return; // should not be reached
}
else if (current.IsEmpty)
{ // the source has completed, stop the pump
//LogPump("Completed");
notifiedCompletion = true;
return;
}
}
// notify cancellation if it happend while we were pumping
if (ct.IsCancellationRequested)
{
//LogPump("We were cancelled!");
throw new OperationCanceledException(ct);
}
}
catch (Exception e)
{
//LogPump("Failed: " + e);
if (!notifiedCompletion && !notifiedError)
{ // notify the target that we crashed while fetching the next
try
{
//LogPump("Push error down to target: " + e.Message);
target.OnError(ExceptionDispatchInfo.Capture(e));
notifiedError = true;
}
catch (Exception x) when(!x.IsFatalError())
{
//LogPump("Failed to notify target of error: " + x.Message);
}
}
throw;
}
finally
{
if (!notifiedCompletion)
{ // we must be sure to complete the target if we haven't done so yet!
//LogPump("Notify target of completion due to unexpected conditions");
target.OnCompleted();
}
//LogPump("Stopped pump");
}
}
public static bool Into <T>(this Result <T> result, IAsyncSource <T> async) => async.SetResult(result);
public static bool Into(this Result result, IAsyncSource async) => async.SetResult(result);
public static bool ErrorInto <T, U>(this Result <T> tResult, IAsyncSource <U> source) => (tResult.IsError && source.Throw <U>(tResult.Error));
public static IAsync <T> AsReceiveOnly <T>(this IAsyncSource <T> source) => source;
public static IAsync AsReceiveOnly(this IAsyncSource source) => source;
public static bool Throw <T>(this IAsyncSource <T> source, Exception ex) => source.SetResult(Result.NewError <T>(ex));
public static bool Return <T>(this IAsyncSource <T> source, T value) => source.SetResult(Result.New <T>(value));
public static bool Return(this IAsyncSource source) => source.SetResult(Result.Void);