Kit.Core/LibExternal/System.Reactive/Linq/Observable/TakeLastBuffer.cs

138 lines
4.3 KiB
C#

// Licensed to the .NET Foundation under one or more agreements.
// The .NET Foundation licenses this file to you under the MIT License.
// See the LICENSE file in the project root for more information.
using System.Collections.Generic;
using System.Reactive.Concurrency;
namespace System.Reactive.Linq.ObservableImpl
{
internal static class TakeLastBuffer<TSource>
{
internal sealed class Count : Producer<IList<TSource>, Count._>
{
private readonly IObservable<TSource> _source;
private readonly int _count;
public Count(IObservable<TSource> source, int count)
{
_source = source;
_count = count;
}
protected override _ CreateSink(IObserver<IList<TSource>> observer) => new(_count, observer);
protected override void Run(_ sink) => sink.Run(_source);
internal sealed class _ : Sink<TSource, IList<TSource>>
{
private readonly int _count;
private readonly Queue<TSource> _queue;
public _(int count, IObserver<IList<TSource>> observer)
: base(observer)
{
_count = count;
_queue = new Queue<TSource>();
}
public override void OnNext(TSource value)
{
_queue.Enqueue(value);
if (_queue.Count > _count)
{
_queue.Dequeue();
}
}
public override void OnCompleted()
{
var res = new List<TSource>(_queue.Count);
while (_queue.Count > 0)
{
res.Add(_queue.Dequeue());
}
ForwardOnNext(res);
ForwardOnCompleted();
}
}
}
internal sealed class Time : Producer<IList<TSource>, Time._>
{
private readonly IObservable<TSource> _source;
private readonly TimeSpan _duration;
private readonly IScheduler _scheduler;
public Time(IObservable<TSource> source, TimeSpan duration, IScheduler scheduler)
{
_source = source;
_duration = duration;
_scheduler = scheduler;
}
protected override _ CreateSink(IObserver<IList<TSource>> observer) => new(_duration, observer);
protected override void Run(_ sink) => sink.Run(_source, _scheduler);
internal sealed class _ : Sink<TSource, IList<TSource>>
{
private readonly TimeSpan _duration;
private readonly Queue<Reactive.TimeInterval<TSource>> _queue;
public _(TimeSpan duration, IObserver<IList<TSource>> observer)
: base(observer)
{
_duration = duration;
_queue = new Queue<Reactive.TimeInterval<TSource>>();
}
private IStopwatch? _watch;
public void Run(IObservable<TSource> source, IScheduler scheduler)
{
_watch = scheduler.StartStopwatch();
Run(source);
}
public override void OnNext(TSource value)
{
var now = _watch!.Elapsed;
_queue.Enqueue(new Reactive.TimeInterval<TSource>(value, now));
Trim(now);
}
public override void OnCompleted()
{
var now = _watch!.Elapsed;
Trim(now);
var res = new List<TSource>(_queue.Count);
while (_queue.Count > 0)
{
res.Add(_queue.Dequeue().Value);
}
ForwardOnNext(res);
ForwardOnCompleted();
}
private void Trim(TimeSpan now)
{
while (_queue.Count > 0 && now - _queue.Peek().Interval >= _duration)
{
_queue.Dequeue();
}
}
}
}
}
}