public static IObservable <TSource> Delay <TSource>(this IObservable <TSource> source, TimeSpan dueTime, IScheduler scheduler)
{
// This code is borrowed from Rx(rx.codeplex.com)
return(Observable.Create <TSource>(observer =>
{
var gate = new object();
var q = new Queue <Timestamped <Notification <TSource> > >();
var active = false;
var running = false;
var cancelable = new SerialDisposable();
var exception = default(Exception);
var subscription = source.Materialize().Timestamp(scheduler).Subscribe(notification =>
{
var shouldRun = false;
lock (gate)
{
if (notification.Value.Kind == NotificationKind.OnError)
{
q.Clear();
q.Enqueue(notification);
exception = notification.Value.Exception;
shouldRun = !running;
}
else
{
q.Enqueue(new Timestamped <Notification <TSource> >(notification.Value, notification.Timestamp.Add(dueTime)));
shouldRun = !active;
active = true;
}
}
if (shouldRun)
{
if (exception != null)
{
observer.OnError(exception);
}
else
{
var d = new SingleAssignmentDisposable();
cancelable.Disposable = d;
d.Disposable = scheduler.Schedule(dueTime, self =>
{
lock (gate)
{
if (exception != null)
{
return;
}
running = true;
}
Notification <TSource> result;
do
{
result = null;
lock (gate)
{
if (q.Count > 0 && q.Peek().Timestamp.CompareTo(scheduler.Now) <= 0)
{
result = q.Dequeue().Value;
}
}
if (result != null)
{
result.Accept(observer);
}
} while (result != null);
var shouldRecurse = false;
var recurseDueTime = TimeSpan.Zero;
var e = default(Exception);
lock (gate)
{
if (q.Count > 0)
{
shouldRecurse = true;
recurseDueTime = TimeSpan.FromTicks(Math.Max(0, q.Peek().Timestamp.Subtract(scheduler.Now).Ticks));
}
else
{
active = false;
}
e = exception;
running = false;
}
if (e != null)
{
observer.OnError(e);
}
else if (shouldRecurse)
{
self(recurseDueTime);
}
});
}
}
});
return new CompositeDisposable(subscription, cancelable);
}));
}
public static IObservable <TSource> Throttle <TSource>(this IObservable <TSource> source, TimeSpan dueTime, IScheduler scheduler)
{
// this code is borrowed from Rx Official(rx.codeplex.com)
return(new AnonymousObservable <TSource>(observer =>
{
var gate = new object();
var value = default(TSource);
var hasValue = false;
var cancelable = new SerialDisposable();
var id = 0UL;
var subscription = source.Subscribe(x =>
{
ulong currentid;
lock (gate)
{
hasValue = true;
value = x;
id = unchecked (id + 1);
currentid = id;
}
var d = new SingleAssignmentDisposable();
cancelable.Disposable = d;
d.Disposable = scheduler.Schedule(dueTime, () =>
{
lock (gate)
{
if (hasValue && id == currentid)
{
observer.OnNext(value);
}
hasValue = false;
}
});
},
exception =>
{
cancelable.Dispose();
lock (gate)
{
observer.OnError(exception);
hasValue = false;
id = unchecked (id + 1);
}
},
() =>
{
cancelable.Dispose();
lock (gate)
{
if (hasValue)
{
observer.OnNext(value);
}
observer.OnCompleted();
hasValue = false;
id = unchecked (id + 1);
}
});
return new CompositeDisposable(subscription, cancelable);
}));
}
public static IObservable <IList <T> > Buffer <T>(this IObservable <T> source, TimeSpan timeSpan, int count, IScheduler scheduler)
{
if (source == null)
{
throw new ArgumentNullException("source");
}
if (count <= 0)
{
throw new ArgumentOutOfRangeException("count <= 0");
}
return(Observable.Create <IList <T> >(observer =>
{
var list = new List <T>();
var gate = new object();
var timerId = 0L;
var d = new CompositeDisposable(2);
var timerD = new SerialDisposable();
// timer
d.Add(timerD);
Action createTimer = () =>
{
var currentTimerId = timerId;
var timerS = new SingleAssignmentDisposable();
timerD.Disposable = timerS; // restart timer(dispose before)
timerS.Disposable = scheduler.Schedule(timeSpan, self =>
{
List <T> currentList;
lock (gate)
{
if (currentTimerId != timerId)
{
return;
}
currentList = list;
if (currentList.Count != 0)
{
list = new List <T>();
}
}
if (currentList.Count != 0)
{
observer.OnNext(currentList);
}
self(timeSpan);
});
};
createTimer();
// subscription
d.Add(source.Subscribe(x =>
{
List <T> currentList = null;
lock (gate)
{
list.Add(x);
if (list.Count == count)
{
currentList = list;
list = new List <T>();
timerId++;
createTimer();
}
}
if (currentList != null)
{
observer.OnNext(currentList);
}
}, observer.OnError, () =>
{
lock (gate)
{
timerId++;
}
var currentList = list;
observer.OnNext(currentList);
observer.OnCompleted();
}));
return d;
}));
}
public static IObservable <IList <T> > Buffer <T>(this IObservable <T> source, TimeSpan timeSpan, TimeSpan timeShift, IScheduler scheduler)
{
if (source == null)
{
throw new ArgumentNullException("source");
}
return(Observable.Create <IList <T> >(observer =>
{
var totalTime = TimeSpan.Zero;
var nextShift = timeShift;
var nextSpan = timeSpan;
var gate = new object();
var q = new Queue <IList <T> >();
var timerD = new SerialDisposable();
var createTimer = default(Action);
createTimer = () =>
{
var m = new SingleAssignmentDisposable();
timerD.Disposable = m;
var isSpan = false;
var isShift = false;
if (nextSpan == nextShift)
{
isSpan = true;
isShift = true;
}
else if (nextSpan < nextShift)
{
isSpan = true;
}
else
{
isShift = true;
}
var newTotalTime = isSpan ? nextSpan : nextShift;
var ts = newTotalTime - totalTime;
totalTime = newTotalTime;
if (isSpan)
{
nextSpan += timeShift;
}
if (isShift)
{
nextShift += timeShift;
}
m.Disposable = scheduler.Schedule(ts, () =>
{
lock (gate)
{
if (isShift)
{
var s = new List <T>();
q.Enqueue(s);
}
if (isSpan)
{
var s = q.Dequeue();
observer.OnNext(s);
}
}
createTimer();
});
};
q.Enqueue(new List <T>());
createTimer();
return source.Subscribe(
x =>
{
lock (gate)
{
foreach (var s in q)
{
s.Add(x);
}
}
},
observer.OnError,
() =>
{
lock (gate)
{
foreach (var list in q)
{
observer.OnNext(list);
}
observer.OnCompleted();
}
}
);
}));
}
public static IObservable <TSource> ThrottleFrame <TSource>(this IObservable <TSource> source, int frameCount, FrameCountType frameCountType = FrameCountType.Update)
{
return(new Observable.AnonymousObservable <TSource>(observer =>
{
var gate = new object();
var value = default(TSource);
var hasValue = false;
var cancelable = new SerialDisposable();
var id = 0UL;
var subscription = source.Subscribe(x =>
{
ulong currentid;
lock (gate)
{
hasValue = true;
value = x;
id = unchecked (id + 1);
currentid = id;
}
var d = new SingleAssignmentDisposable();
cancelable.Disposable = d;
d.Disposable = IntervalFrame(frameCount, frameCountType)
.Subscribe(_ =>
{
lock (gate)
{
if (hasValue && id == currentid)
{
observer.OnNext(value);
}
hasValue = false;
}
});
},
exception =>
{
cancelable.Dispose();
lock (gate)
{
observer.OnError(exception);
hasValue = false;
id = unchecked (id + 1);
}
},
() =>
{
cancelable.Dispose();
lock (gate)
{
if (hasValue)
{
observer.OnNext(value);
}
observer.OnCompleted();
hasValue = false;
id = unchecked (id + 1);
}
});
return new CompositeDisposable(subscription, cancelable);
}));
}
public static IObservable <TSource> Catch <TSource>(this IEnumerable <IObservable <TSource> > sources)
{
// this code is borrowed from RxOfficial(rx.codeplex.com) and modified
return(Observable.Create <TSource>(observer =>
{
var gate = new object();
var isDisposed = false;
var e = sources.AsSafeEnumerable().GetEnumerator();
var subscription = new SerialDisposable();
var lastException = default(Exception);
var cancelable = Scheduler.DefaultSchedulers.TailRecursion.Schedule(self =>
{
lock (gate)
{
var current = default(IObservable <TSource>);
var hasNext = false;
var ex = default(Exception);
if (!isDisposed)
{
try
{
hasNext = e.MoveNext();
if (hasNext)
{
current = e.Current;
}
else
{
e.Dispose();
}
}
catch (Exception exception)
{
ex = exception;
e.Dispose();
}
}
else
{
return;
}
if (ex != null)
{
observer.OnError(ex);
return;
}
if (!hasNext)
{
if (lastException != null)
{
observer.OnError(lastException);
}
else
{
observer.OnCompleted();
}
return;
}
var d = new SingleAssignmentDisposable();
subscription.Disposable = d;
d.Disposable = current.Subscribe(observer.OnNext, exception =>
{
lastException = exception;
self();
}, observer.OnCompleted);
}
});
return new CompositeDisposable(subscription, cancelable, Disposable.Create(() =>
{
lock (gate)
{
e.Dispose();
isDisposed = true;
}
}));
}));
}
public static IObservable <T> Switch <T>(this IObservable <IObservable <T> > sources)
{
// this code is borrwed from RxOfficial(rx.codeplex.com)
return(Observable.Create <T>(observer =>
{
var gate = new object();
var innerSubscription = new SerialDisposable();
var isStopped = false;
var latest = 0UL;
var hasLatest = false;
var subscription = sources.Subscribe(
innerSource =>
{
var id = default(ulong);
lock (gate)
{
id = unchecked (++latest);
hasLatest = true;
}
var d = new SingleAssignmentDisposable();
innerSubscription.Disposable = d;
d.Disposable = innerSource.Subscribe(
x =>
{
lock (gate)
{
if (latest == id)
{
observer.OnNext(x);
}
}
},
exception =>
{
lock (gate)
{
if (latest == id)
{
observer.OnError(exception);
}
}
},
() =>
{
lock (gate)
{
if (latest == id)
{
hasLatest = false;
if (isStopped)
{
observer.OnCompleted();
}
}
}
});
},
exception =>
{
lock (gate)
observer.OnError(exception);
},
() =>
{
lock (gate)
{
isStopped = true;
if (!hasLatest)
{
observer.OnCompleted();
}
}
});
return new CompositeDisposable(subscription, innerSubscription);
}));
}
/// <summary>
/// <para>Specialized for single async operations like Task.WhenAll, Zip.Take(1).</para>
/// <para>If sequence is empty, return T[0] array.</para>
/// </summary>
public static IObservable <T[]> WhenAll <T>(this IEnumerable <IObservable <T> > sources)
{
var array = sources as IObservable <T>[];
if (array != null)
{
return(WhenAll(array));
}
return(Observable.Create <T[]>(observer =>
{
var _sources = sources as IList <IObservable <T> >;
if (_sources == null)
{
_sources = new List <IObservable <T> >();
foreach (var item in sources)
{
_sources.Add(item);
}
}
var gate = new object();
var length = _sources.Count;
var completedCount = 0;
var values = new T[length];
if (length == 0)
{
observer.OnNext(values);
observer.OnCompleted();
return Disposable.Empty;
}
var subscriptions = new IDisposable[length];
for (int index = 0; index < length; index++)
{
var source = _sources[index];
var capturedIndex = index;
var d = new SingleAssignmentDisposable();
d.Disposable = source.Subscribe(x =>
{
lock (gate)
{
values[capturedIndex] = x;
}
}, ex =>
{
lock (gate)
{
observer.OnError(ex);
}
}, () =>
{
lock (gate)
{
completedCount++;
if (completedCount == length)
{
observer.OnNext(values);
observer.OnCompleted();
}
}
});
subscriptions[index] = d;
}
return new CompositeDisposable(subscriptions);
}));
}
public static IObservable <IList <TSource> > CombineLatest <TSource>(params IObservable <TSource>[] sources)
{
// this code is borrwed from RxOfficial(rx.codeplex.com)
return(Observable.Create <IList <TSource> >(observer =>
{
var srcs = sources.ToArray();
var N = srcs.Length;
var hasValue = new bool[N];
var hasValueAll = false;
var values = new List <TSource>(N);
for (int i = 0; i < N; i++)
{
values.Add(default(TSource));
}
var isDone = new bool[N];
var next = new Action <int>(i =>
{
hasValue[i] = true;
if (hasValueAll || (hasValueAll = hasValue.All(x => x)))
{
var res = values.ToList();
observer.OnNext(res);
}
else if (isDone.Where((x, j) => j != i).All(x => x))
{
observer.OnCompleted();
return;
}
});
var done = new Action <int>(i =>
{
isDone[i] = true;
if (isDone.All(x => x))
{
observer.OnCompleted();
return;
}
});
var subscriptions = new SingleAssignmentDisposable[N];
var gate = new object();
for (int i = 0; i < N; i++)
{
var j = i;
subscriptions[j] = new SingleAssignmentDisposable
{
Disposable = srcs[j].Synchronize(gate).Subscribe(
x =>
{
values[j] = x;
next(j);
},
observer.OnError,
() =>
{
done(j);
}
)
};
}
return new CompositeDisposable(subscriptions);
}));
}
static IObservable <T> ConcatCore <T>(IEnumerable <IObservable <T> > sources)
{
return(Observable.Create <T>(observer =>
{
var isDisposed = false;
var e = sources.AsSafeEnumerable().GetEnumerator();
var subscription = new SerialDisposable();
var gate = new object();
var schedule = Scheduler.DefaultSchedulers.TailRecursion.Schedule(self =>
{
lock (gate)
{
if (isDisposed)
{
return;
}
var current = default(IObservable <T>);
var hasNext = false;
var ex = default(Exception);
try
{
hasNext = e.MoveNext();
if (hasNext)
{
current = e.Current;
if (current == null)
{
throw new InvalidOperationException("sequence is null.");
}
}
else
{
e.Dispose();
}
}
catch (Exception exception)
{
ex = exception;
e.Dispose();
}
if (ex != null)
{
observer.OnError(ex);
return;
}
if (!hasNext)
{
observer.OnCompleted();
return;
}
var source = e.Current;
var d = new SingleAssignmentDisposable();
subscription.Disposable = d;
d.Disposable = source.Subscribe(observer.OnNext, observer.OnError, self); // OnCompleted, run self
}
});
return new CompositeDisposable(schedule, subscription, Disposable.Create(() =>
{
lock (gate)
{
isDisposed = true;
e.Dispose();
}
}));
}));
}
public static IObservable <IList <T> > Zip <T>(params IObservable <T>[] sources)
{
return(Observable.Create <IList <T> >(observer =>
{
var gate = new object();
var length = sources.Length;
var queues = new Queue <T> [length];
for (int i = 0; i < length; i++)
{
queues[i] = new Queue <T>();
}
var isDone = new bool[length];
Action <int> dequeue = index =>
{
lock (gate)
{
if (queues.All(x => x.Count > 0))
{
var result = queues.Select(x => x.Dequeue()).ToList();
observer.OnNext(result);
return;
}
if (isDone.Where((x, i) => i != index).All(x => x))
{
observer.OnCompleted();
return;
}
}
};
var subscriptions = sources
.Select((source, index) =>
{
var d = new SingleAssignmentDisposable();
d.Disposable = source.Subscribe(x =>
{
lock (gate)
{
queues[index].Enqueue(x);
dequeue(index);
}
}, ex =>
{
lock (gate)
{
observer.OnError(ex);
}
}, () =>
{
lock (gate)
{
isDone[index] = true;
if (isDone.All(x => x))
{
observer.OnCompleted();
}
else
{
d.Dispose();
}
}
});
return d;
})
.ToArray();
return new CompositeDisposable(subscriptions)
{
Disposable.Create(() =>
{
lock (gate)
{
foreach (var item in queues)
{
item.Clear();
}
}
})
};
}));
}
public static IObservable <T> Merge <T>(this IObservable <IObservable <T> > sources, int maxConcurrent)
{
// this code is borrwed from RxOfficial(rx.codeplex.com)
return(Observable.Create <T>(observer =>
{
var gate = new object();
var q = new Queue <IObservable <T> >();
var isStopped = false;
var group = new CompositeDisposable();
var activeCount = 0;
var subscribe = default(Action <IObservable <T> >);
subscribe = xs =>
{
var subscription = new SingleAssignmentDisposable();
group.Add(subscription);
subscription.Disposable = xs.Subscribe(
x =>
{
lock (gate)
observer.OnNext(x);
},
exception =>
{
lock (gate)
observer.OnError(exception);
},
() =>
{
group.Remove(subscription);
lock (gate)
{
if (q.Count > 0)
{
var s = q.Dequeue();
subscribe(s);
}
else
{
activeCount--;
if (isStopped && activeCount == 0)
{
observer.OnCompleted();
}
}
}
});
};
group.Add(sources.Subscribe(
innerSource =>
{
lock (gate)
{
if (activeCount < maxConcurrent)
{
activeCount++;
subscribe(innerSource);
}
else
{
q.Enqueue(innerSource);
}
}
},
exception =>
{
lock (gate)
observer.OnError(exception);
},
() =>
{
lock (gate)
{
isStopped = true;
if (activeCount == 0)
{
observer.OnCompleted();
}
}
}));
return group;
}));
}
public static IObservable <T> Amb <T>(this IObservable <T> source, IObservable <T> second)
{
return(Observable.Create <T>(observer =>
{
var choice = AmbState.Neither;
var gate = new Object();
var leftSubscription = new SingleAssignmentDisposable();
var rightSubscription = new SingleAssignmentDisposable();
leftSubscription.Disposable = source.Subscribe(x =>
{
lock (gate)
{
if (choice == AmbState.Neither)
{
choice = AmbState.Left;
rightSubscription.Dispose();
// We can avoid lock every call but I'm not confident in AOT Safety.
// I'll try, check...
// left.Observer = observer;
}
}
if (choice == AmbState.Left)
{
observer.OnNext(x);
}
}, ex =>
{
lock (gate)
{
if (choice == AmbState.Neither)
{
choice = AmbState.Left;
rightSubscription.Dispose();
}
}
if (choice == AmbState.Left)
{
observer.OnError(ex);
}
}, () =>
{
lock (gate)
{
if (choice == AmbState.Neither)
{
choice = AmbState.Left;
rightSubscription.Dispose();
}
}
if (choice == AmbState.Left)
{
observer.OnCompleted();
}
});
rightSubscription.Disposable = second.Subscribe(x =>
{
lock (gate)
{
if (choice == AmbState.Neither)
{
choice = AmbState.Right;
leftSubscription.Dispose();
}
}
if (choice == AmbState.Right)
{
observer.OnNext(x);
}
}, ex =>
{
lock (gate)
{
if (choice == AmbState.Neither)
{
choice = AmbState.Right;
leftSubscription.Dispose();
}
}
if (choice == AmbState.Right)
{
observer.OnError(ex);
}
}, () =>
{
lock (gate)
{
if (choice == AmbState.Neither)
{
choice = AmbState.Right;
leftSubscription.Dispose();
}
}
if (choice == AmbState.Right)
{
observer.OnCompleted();
}
});
return new CompositeDisposable {
leftSubscription, rightSubscription
};
}));
}
