99 lines
2.6 KiB
C#
99 lines
2.6 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.Concurrent;
|
|
using System.Collections.Generic;
|
|
using System.Diagnostics;
|
|
using System.Reactive.Disposables;
|
|
using System.Threading;
|
|
|
|
namespace System.Reactive.Linq.ObservableImpl
|
|
{
|
|
internal sealed class GetEnumerator<TSource> : IEnumerator<TSource>, IObserver<TSource>
|
|
{
|
|
private readonly ConcurrentQueue<TSource> _queue;
|
|
private TSource? _current;
|
|
private Exception? _error;
|
|
private bool _done;
|
|
private bool _disposed;
|
|
private SingleAssignmentDisposableValue _subscription;
|
|
|
|
private readonly SemaphoreSlim _gate;
|
|
|
|
public GetEnumerator()
|
|
{
|
|
_queue = new ConcurrentQueue<TSource>();
|
|
_gate = new SemaphoreSlim(0);
|
|
}
|
|
|
|
public IEnumerator<TSource> Run(IObservable<TSource> source)
|
|
{
|
|
//
|
|
// [OK] Use of unsafe Subscribe: non-pretentious exact mirror with the dual GetEnumerator method.
|
|
//
|
|
_subscription.Disposable = source.Subscribe/*Unsafe*/(this);
|
|
return this;
|
|
}
|
|
|
|
public void OnNext(TSource value)
|
|
{
|
|
_queue.Enqueue(value);
|
|
_gate.Release();
|
|
}
|
|
|
|
public void OnError(Exception error)
|
|
{
|
|
_error = error;
|
|
_subscription.Dispose();
|
|
_gate.Release();
|
|
}
|
|
|
|
public void OnCompleted()
|
|
{
|
|
_done = true;
|
|
_subscription.Dispose();
|
|
_gate.Release();
|
|
}
|
|
|
|
public bool MoveNext()
|
|
{
|
|
_gate.Wait();
|
|
|
|
if (_disposed)
|
|
{
|
|
throw new ObjectDisposedException("");
|
|
}
|
|
|
|
if (_queue.TryDequeue(out _current))
|
|
{
|
|
return true;
|
|
}
|
|
|
|
_error?.Throw();
|
|
|
|
Debug.Assert(_done);
|
|
|
|
_gate.Release(); // In the (rare) case the user calls MoveNext again we shouldn't block!
|
|
return false;
|
|
}
|
|
|
|
public TSource Current => _current!; // NB: Only called after MoveNext returns true and assigns a value.
|
|
|
|
object Collections.IEnumerator.Current => _current!;
|
|
|
|
public void Dispose()
|
|
{
|
|
_subscription.Dispose();
|
|
|
|
_disposed = true;
|
|
_gate.Release();
|
|
}
|
|
|
|
public void Reset()
|
|
{
|
|
throw new NotSupportedException();
|
|
}
|
|
}
|
|
}
|