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Diffstat (limited to 'Rx/NET/Source/System.Reactive.Linq/Reactive/Linq/Observable/Skip.cs')
| -rw-r--r-- | Rx/NET/Source/System.Reactive.Linq/Reactive/Linq/Observable/Skip.cs | 151 |
1 files changed, 151 insertions, 0 deletions
diff --git a/Rx/NET/Source/System.Reactive.Linq/Reactive/Linq/Observable/Skip.cs b/Rx/NET/Source/System.Reactive.Linq/Reactive/Linq/Observable/Skip.cs new file mode 100644 index 0000000..a092d99 --- /dev/null +++ b/Rx/NET/Source/System.Reactive.Linq/Reactive/Linq/Observable/Skip.cs @@ -0,0 +1,151 @@ +// Copyright (c) Microsoft Open Technologies, Inc. All rights reserved. See License.txt in the project root for license information. + +#if !NO_PERF +using System; +using System.Reactive.Concurrency; +using System.Reactive.Disposables; + +namespace System.Reactive.Linq.Observαble +{ + class Skip<TSource> : Producer<TSource> + { + private readonly IObservable<TSource> _source; + private readonly int _count; + private readonly TimeSpan _duration; + internal readonly IScheduler _scheduler; + + public Skip(IObservable<TSource> source, int count) + { + _source = source; + _count = count; + } + + public Skip(IObservable<TSource> source, TimeSpan duration, IScheduler scheduler) + { + _source = source; + _duration = duration; + _scheduler = scheduler; + } + + public IObservable<TSource> Ω(int count) + { + // + // Sum semantics: + // + // xs --o--o--o--o--o--o--| xs --o--o--o--o--o--o--| + // xs.Skip(2) --x--x--o--o--o--o--| xs.Skip(3) --x--x--x--o--o--o--| + // xs.Skip(2).Skip(3) --------x--x--x--o--| xs.Skip(3).Skip(2) -----------x--x--o--| + // + return new Skip<TSource>(_source, _count + count); + } + + public IObservable<TSource> Ω(TimeSpan duration) + { + // + // Maximum semantics: + // + // t 0--1--2--3--4--5--6--7-> t 0--1--2--3--4--5--6--7-> + // + // xs --o--o--o--o--o--o--| xs --o--o--o--o--o--o--| + // xs.Skip(2s) xxxxxxx-o--o--o--o--| xs.Skip(3s) xxxxxxxxxx-o--o--o--| + // xs.Skip(2s).Skip(3s) xxxxxxxxxx-o--o--o--| xs.Skip(3s).Skip(2s) xxxxxxx----o--o--o--| + // + if (duration <= _duration) + return this; + else + return new Skip<TSource>(_source, duration, _scheduler); + } + + protected override IDisposable Run(IObserver<TSource> observer, IDisposable cancel, Action<IDisposable> setSink) + { + if (_scheduler == null) + { + var sink = new _(this, observer, cancel); + setSink(sink); + return _source.SubscribeSafe(sink); + } + else + { + var sink = new τ(this, observer, cancel); + setSink(sink); + return sink.Run(); + } + } + + class _ : Sink<TSource>, IObserver<TSource> + { + private readonly Skip<TSource> _parent; + private int _remaining; + + public _(Skip<TSource> parent, IObserver<TSource> observer, IDisposable cancel) + : base(observer, cancel) + { + _parent = parent; + _remaining = _parent._count; + } + + public void OnNext(TSource value) + { + if (_remaining <= 0) + base._observer.OnNext(value); + else + _remaining--; + } + + public void OnError(Exception error) + { + base._observer.OnError(error); + base.Dispose(); + } + + public void OnCompleted() + { + base._observer.OnCompleted(); + base.Dispose(); + } + } + + class τ : Sink<TSource>, IObserver<TSource> + { + private readonly Skip<TSource> _parent; + private volatile bool _open; + + public τ(Skip<TSource> parent, IObserver<TSource> observer, IDisposable cancel) + : base(observer, cancel) + { + _parent = parent; + } + + public IDisposable Run() + { + var t = _parent._scheduler.Schedule(_parent._duration, Tick); + var d = _parent._source.SubscribeSafe(this); + return new CompositeDisposable(t, d); + } + + private void Tick() + { + _open = true; + } + + public void OnNext(TSource value) + { + if (_open) + base._observer.OnNext(value); + } + + public void OnError(Exception error) + { + base._observer.OnError(error); + base.Dispose(); + } + + public void OnCompleted() + { + base._observer.OnCompleted(); + base.Dispose(); + } + } + } +} +#endif
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