<PackageReference Include="System.Reactive" Version="4.0.0-preview.4.build.391" />

TakeLast<TSource>

static class TakeLast<TSource>
using System.Collections.Generic; using System.Reactive.Concurrency; using System.Reactive.Disposables; namespace System.Reactive.Linq.ObservableImpl { internal static class TakeLast<TSource> { internal sealed class Count : Producer<TSource, Count._> { internal sealed class _ : Sink<TSource>, IObserver<TSource> { private readonly Count _parent; private Queue<TSource> _queue; private SingleAssignmentDisposable _subscription; private SingleAssignmentDisposable _loop; public _(Count parent, IObserver<TSource> observer, IDisposable cancel) : base(observer, cancel) { _parent = parent; _queue = new Queue<TSource>(); } public IDisposable Run() { _subscription = new SingleAssignmentDisposable(); _loop = new SingleAssignmentDisposable(); _subscription.Disposable = ObservableExtensions.SubscribeSafe<TSource>(_parent._source, (IObserver<TSource>)this); return StableCompositeDisposable.Create(_subscription, _loop); } public void OnNext(TSource value) { _queue.Enqueue(value); if (_queue.Count > _parent._count) _queue.Dequeue(); } public void OnError(Exception error) { _observer.OnError(error); base.Dispose(); } public void OnCompleted() { _subscription.Dispose(); ISchedulerLongRunning schedulerLongRunning = _parent._loopScheduler.AsLongRunning(); if (schedulerLongRunning != null) _loop.Disposable = schedulerLongRunning.ScheduleLongRunning(Loop); else _loop.Disposable = _parent._loopScheduler.Schedule(LoopRec); } private void LoopRec(Action recurse) { if (_queue.Count > 0) { _observer.OnNext(_queue.Dequeue()); recurse(); } else { _observer.OnCompleted(); base.Dispose(); } } private void Loop(ICancelable cancel) { int num = _queue.Count; while (!cancel.IsDisposed) { if (num == 0) { _observer.OnCompleted(); break; } _observer.OnNext(_queue.Dequeue()); num--; } base.Dispose(); } } private readonly IObservable<TSource> _source; private readonly int _count; private readonly IScheduler _loopScheduler; public Count(IObservable<TSource> source, int count, IScheduler loopScheduler) { _source = source; _count = count; _loopScheduler = loopScheduler; } protected override _ CreateSink(IObserver<TSource> observer, IDisposable cancel) { return new _(this, observer, cancel); } protected override IDisposable Run(_ sink) { return sink.Run(); } } internal sealed class Time : Producer<TSource, Time._> { internal sealed class _ : Sink<TSource>, IObserver<TSource> { private readonly Time _parent; private Queue<System.Reactive.TimeInterval<TSource>> _queue; private SingleAssignmentDisposable _subscription; private SingleAssignmentDisposable _loop; private IStopwatch _watch; public _(Time parent, IObserver<TSource> observer, IDisposable cancel) : base(observer, cancel) { _parent = parent; _queue = new Queue<System.Reactive.TimeInterval<TSource>>(); } public IDisposable Run() { _subscription = new SingleAssignmentDisposable(); _loop = new SingleAssignmentDisposable(); _watch = _parent._scheduler.StartStopwatch(); _subscription.Disposable = ObservableExtensions.SubscribeSafe<TSource>(_parent._source, (IObserver<TSource>)this); return StableCompositeDisposable.Create(_subscription, _loop); } public void OnNext(TSource value) { TimeSpan elapsed = _watch.Elapsed; _queue.Enqueue(new System.Reactive.TimeInterval<TSource>(value, elapsed)); Trim(elapsed); } public void OnError(Exception error) { _observer.OnError(error); base.Dispose(); } public void OnCompleted() { _subscription.Dispose(); TimeSpan elapsed = _watch.Elapsed; Trim(elapsed); ISchedulerLongRunning schedulerLongRunning = _parent._loopScheduler.AsLongRunning(); if (schedulerLongRunning != null) _loop.Disposable = schedulerLongRunning.ScheduleLongRunning(Loop); else _loop.Disposable = _parent._loopScheduler.Schedule(LoopRec); } private void LoopRec(Action recurse) { if (_queue.Count > 0) { _observer.OnNext(_queue.Dequeue().Value); recurse(); } else { _observer.OnCompleted(); base.Dispose(); } } private void Loop(ICancelable cancel) { int num = _queue.Count; while (!cancel.IsDisposed) { if (num == 0) { _observer.OnCompleted(); break; } _observer.OnNext(_queue.Dequeue().Value); num--; } base.Dispose(); } private void Trim(TimeSpan now) { while (_queue.Count > 0 && now - _queue.Peek().Interval >= _parent._duration) { _queue.Dequeue(); } } } private readonly IObservable<TSource> _source; private readonly TimeSpan _duration; private readonly IScheduler _scheduler; private readonly IScheduler _loopScheduler; public Time(IObservable<TSource> source, TimeSpan duration, IScheduler scheduler, IScheduler loopScheduler) { _source = source; _duration = duration; _scheduler = scheduler; _loopScheduler = loopScheduler; } protected override _ CreateSink(IObserver<TSource> observer, IDisposable cancel) { return new _(this, observer, cancel); } protected override IDisposable Run(_ sink) { return sink.Run(); } } } }