WithLatestFrom<TFirst, TSecond, TResult>
sealed class WithLatestFrom<TFirst, TSecond, TResult> : Producer<TResult, _<TFirst, TSecond, TResult>>
using System.Reactive.Disposables;
namespace System.Reactive.Linq.ObservableImpl
{
internal sealed class WithLatestFrom<TFirst, TSecond, TResult> : Producer<TResult, WithLatestFrom<TFirst, TSecond, TResult>._>
{
internal sealed class _ : Sink<TResult>
{
private sealed class FirstObserver : IObserver<TFirst>
{
private readonly _ _parent;
public FirstObserver(_ parent)
{
_parent = parent;
}
public void OnCompleted()
{
lock (_parent._gate) {
_parent._observer.OnCompleted();
_parent.Dispose();
}
}
public void OnError(Exception error)
{
lock (_parent._gate) {
_parent._observer.OnError(error);
_parent.Dispose();
}
}
public void OnNext(TFirst value)
{
if (_parent._hasLatest) {
TSecond latest = default(TSecond);
lock (_parent._latestGate) {
latest = _parent._latest;
}
TResult val = default(TResult);
try {
val = _parent._resultSelector(value, latest);
} catch (Exception error) {
lock (_parent._gate) {
_parent._observer.OnError(error);
_parent.Dispose();
}
return;
}
lock (_parent._gate) {
_parent._observer.OnNext(val);
}
}
}
}
private sealed class SecondObserver : IObserver<TSecond>
{
private readonly _ _parent;
private readonly IDisposable _self;
public SecondObserver(_ parent, IDisposable self)
{
_parent = parent;
_self = self;
}
public void OnCompleted()
{
_self.Dispose();
}
public void OnError(Exception error)
{
lock (_parent._gate) {
_parent._observer.OnError(error);
_parent.Dispose();
}
}
public void OnNext(TSecond value)
{
lock (_parent._latestGate) {
_parent._latest = value;
}
if (!_parent._hasLatest)
_parent._hasLatest = true;
}
}
private readonly Func<TFirst, TSecond, TResult> _resultSelector;
private object _gate;
private volatile bool _hasLatest;
private TSecond _latest;
private object _latestGate;
public _(Func<TFirst, TSecond, TResult> resultSelector, IObserver<TResult> observer, IDisposable cancel)
: base(observer, cancel)
{
_resultSelector = resultSelector;
}
public IDisposable Run(IObservable<TFirst> first, IObservable<TSecond> second)
{
_gate = new object();
_latestGate = new object();
SingleAssignmentDisposable singleAssignmentDisposable = new SingleAssignmentDisposable();
FirstObserver observer = new FirstObserver(this);
SecondObserver observer2 = new SecondObserver(this, singleAssignmentDisposable);
singleAssignmentDisposable.Disposable = ObservableExtensions.SubscribeSafe<TSecond>(second, (IObserver<TSecond>)observer2);
return StableCompositeDisposable.Create(ObservableExtensions.SubscribeSafe<TFirst>(first, (IObserver<TFirst>)observer), singleAssignmentDisposable);
}
}
private readonly IObservable<TFirst> _first;
private readonly IObservable<TSecond> _second;
private readonly Func<TFirst, TSecond, TResult> _resultSelector;
public WithLatestFrom(IObservable<TFirst> first, IObservable<TSecond> second, Func<TFirst, TSecond, TResult> resultSelector)
{
_first = first;
_second = second;
_resultSelector = resultSelector;
}
protected override _ CreateSink(IObserver<TResult> observer, IDisposable cancel)
{
return new _(_resultSelector, observer, cancel);
}
protected override IDisposable Run(_ sink)
{
return sink.Run(_first, _second);
}
}
}