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Diffstat (limited to 'Rx.NET/System.Reactive.Core/Reactive/Internal/Producer.cs')
| -rw-r--r-- | Rx.NET/System.Reactive.Core/Reactive/Internal/Producer.cs | 87 |
1 files changed, 87 insertions, 0 deletions
diff --git a/Rx.NET/System.Reactive.Core/Reactive/Internal/Producer.cs b/Rx.NET/System.Reactive.Core/Reactive/Internal/Producer.cs new file mode 100644 index 0000000..93b83de --- /dev/null +++ b/Rx.NET/System.Reactive.Core/Reactive/Internal/Producer.cs @@ -0,0 +1,87 @@ +// Copyright (c) Microsoft Open Technologies, Inc. All rights reserved. See License.txt in the project root for license information. + +#if !NO_PERF +using System.Reactive.Concurrency; +using System.Reactive.Disposables; + +namespace System.Reactive +{ + /// <summary> + /// Base class for implementation of query operators, providing performance benefits over the use of Observable.Create. + /// </summary> + /// <typeparam name="TSource">Type of the resulting sequence's elements.</typeparam> + internal abstract class Producer<TSource> : IObservable<TSource> + { + /// <summary> + /// Publicly visible Subscribe method. + /// </summary> + /// <param name="observer">Observer to send notifications on. The implementation of a producer must ensure the correct message grammar on the observer.</param> + /// <returns>IDisposable to cancel the subscription. This causes the underlying sink to be notified of unsubscription, causing it to prevent further messages from being sent to the observer.</returns> + public IDisposable Subscribe(IObserver<TSource> observer) + { + if (observer == null) + throw new ArgumentNullException("observer"); + + return SubscribeRaw(observer, true); + } + + internal IDisposable SubscribeRaw(IObserver<TSource> observer, bool enableSafeguard) + { + var state = new State(); + state.observer = observer; + state.sink = new SingleAssignmentDisposable(); + state.subscription = new SingleAssignmentDisposable(); + + var d = new CompositeDisposable(2) { state.sink, state.subscription }; + + // + // See AutoDetachObserver.cs for more information on the safeguarding requirement and + // its implementation aspects. + // + if (enableSafeguard) + { + state.observer = SafeObserver<TSource>.Create(state.observer, d); + } + + if (CurrentThreadScheduler.IsScheduleRequired) + { + CurrentThreadScheduler.Instance.Schedule(state, Run); + } + else + { + state.subscription.Disposable = this.Run(state.observer, state.subscription, state.Assign); + } + + return d; + } + + struct State + { + public SingleAssignmentDisposable sink; + public SingleAssignmentDisposable subscription; + public IObserver<TSource> observer; + + public void Assign(IDisposable s) + { + sink.Disposable = s; + } + } + + private IDisposable Run(IScheduler _, State x) + { + x.subscription.Disposable = this.Run(x.observer, x.subscription, x.Assign); + return Disposable.Empty; + } + + /// <summary> + /// Core implementation of the query operator, called upon a new subscription to the producer object. + /// </summary> + /// <param name="observer">Observer to send notifications on. The implementation of a producer must ensure the correct message grammar on the observer.</param> + /// <param name="cancel">The subscription disposable object returned from the Run call, passed in such that it can be forwarded to the sink, allowing it to dispose the subscription upon sending a final message (or prematurely for other reasons).</param> + /// <param name="setSink">Callback to communicate the sink object to the subscriber, allowing consumers to tunnel a Dispose call into the sink, which can stop the processing.</param> + /// <returns>Disposable representing all the resources and/or subscriptions the operator uses to process events.</returns> + /// <remarks>The <paramref name="observer">observer</paramref> passed in to this method is not protected using auto-detach behavior upon an OnError or OnCompleted call. The implementation must ensure proper resource disposal and enforce the message grammar.</remarks> + protected abstract IDisposable Run(IObserver<TSource> observer, IDisposable cancel, Action<IDisposable> setSink); + } +} +#endif
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