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

143 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.Disposables;
using System.Threading;
namespace System.Reactive.Linq.ObservableImpl
{
internal sealed class Catch<TSource> : Producer<TSource, Catch<TSource>._>
{
private readonly IEnumerable<IObservable<TSource>> _sources;
public Catch(IEnumerable<IObservable<TSource>> sources)
{
_sources = sources;
}
protected override _ CreateSink(IObserver<TSource> observer) => new(observer);
protected override void Run(_ sink) => sink.Run(_sources);
internal sealed class _ : TailRecursiveSink<TSource>
{
public _(IObserver<TSource> observer)
: base(observer)
{
}
protected override IEnumerable<IObservable<TSource>>? Extract(IObservable<TSource> source)
{
if (source is Catch<TSource> @catch)
{
return @catch._sources;
}
return null;
}
private Exception? _lastException;
public override void OnError(Exception error)
{
_lastException = error;
Recurse();
}
protected override void Done()
{
if (_lastException != null)
{
ForwardOnError(_lastException);
}
else
{
ForwardOnCompleted();
}
}
protected override bool Fail(Exception error)
{
//
// Note that the invocation of _recurse in OnError will
// cause the next MoveNext operation to be enqueued, so
// we will still return to the caller immediately.
//
OnError(error);
return true;
}
}
}
internal sealed class Catch<TSource, TException> : Producer<TSource, Catch<TSource, TException>._> where TException : Exception
{
private readonly IObservable<TSource> _source;
private readonly Func<TException, IObservable<TSource>> _handler;
public Catch(IObservable<TSource> source, Func<TException, IObservable<TSource>> handler)
{
_source = source;
_handler = handler;
}
protected override _ CreateSink(IObserver<TSource> observer) => new(_handler, observer);
protected override void Run(_ sink) => sink.Run(_source);
internal sealed class _ : IdentitySink<TSource>
{
private readonly Func<TException, IObservable<TSource>> _handler;
public _(Func<TException, IObservable<TSource>> handler, IObserver<TSource> observer)
: base(observer)
{
_handler = handler;
}
private bool _once;
private SerialDisposableValue _subscription;
public override void Run(IObservable<TSource> source)
{
_subscription.TrySetFirst(source.SubscribeSafe(this));
}
protected override void Dispose(bool disposing)
{
if (disposing)
{
_subscription.Dispose();
}
base.Dispose(disposing);
}
public override void OnError(Exception error)
{
if (!Volatile.Read(ref _once) && error is TException e)
{
IObservable<TSource> result;
try
{
result = _handler(e);
}
catch (Exception ex)
{
ForwardOnError(ex);
return;
}
Volatile.Write(ref _once, true);
_subscription.Disposable = result.SubscribeSafe(this);
}
else
{
ForwardOnError(error);
}
}
}
}
}