Kit.Core/LibExternal/System.Reactive/Joins/JoinObserver.cs

106 lines
2.9 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.Disposables;
using System.Reactive.Linq;
namespace System.Reactive.Joins
{
internal interface IJoinObserver : IDisposable
{
void Subscribe(object gate);
void Dequeue();
}
internal sealed class JoinObserver<T> : ObserverBase<Notification<T>>, IJoinObserver
{
private object? _gate;
private readonly IObservable<T> _source;
private readonly Action<Exception> _onError;
private readonly List<ActivePlan> _activePlans;
private SingleAssignmentDisposableValue _subscription;
private bool _isDisposed;
public JoinObserver(IObservable<T> source, Action<Exception> onError)
{
_source = source;
_onError = onError;
Queue = new Queue<Notification<T>>();
_activePlans = new List<ActivePlan>();
}
public Queue<Notification<T>> Queue { get; }
public void AddActivePlan(ActivePlan activePlan)
{
_activePlans.Add(activePlan);
}
public void Subscribe(object gate)
{
_gate = gate;
_subscription.Disposable = _source.Materialize().SubscribeSafe(this);
}
public void Dequeue()
{
Queue.Dequeue();
}
protected override void OnNextCore(Notification<T> notification)
{
lock (_gate!) // NB: Called after Subscribe(object) is called.
{
if (!_isDisposed)
{
if (notification.Kind == NotificationKind.OnError)
{
_onError(notification.Exception!);
return;
}
Queue.Enqueue(notification);
foreach (var activePlan in _activePlans.ToArray()) // Working on a copy since _activePlans might change while iterating.
{
activePlan.Match();
}
}
}
}
protected override void OnErrorCore(Exception exception)
{
}
protected override void OnCompletedCore()
{
}
internal void RemoveActivePlan(ActivePlan activePlan)
{
_activePlans.Remove(activePlan);
if (_activePlans.Count == 0)
{
Dispose();
}
}
protected override void Dispose(bool disposing)
{
base.Dispose(disposing);
if (!_isDisposed)
{
if (disposing)
{
_subscription.Dispose();
}
_isDisposed = true;
}
}
}
}