Kit.Core/LibExternal/System.Reactive/Concurrency/Scheduler.Services.cs

80 lines
4.5 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.
namespace System.Reactive.Concurrency
{
//
// NOTE: When adding interface-based optimizations here, ensure to add the type to the list of
// interface-based optimizations used by DisableOptimizations and the RawScheduler type.
//
public static partial class Scheduler
{
internal static Type[] Optimizations = {
typeof(ISchedulerLongRunning),
typeof(IStopwatchProvider),
typeof(ISchedulerPeriodic)
/* update this list if new interface-based optimizations are added */
};
/// <summary>
/// Returns the <see cref="ISchedulerLongRunning"/> implementation of the specified scheduler, or <c>null</c> if no such implementation is available.
/// </summary>
/// <param name="scheduler">Scheduler to get the <see cref="ISchedulerLongRunning"/> implementation for.</param>
/// <returns>The scheduler's <see cref="ISchedulerLongRunning"/> implementation if available; <c>null</c> otherwise.</returns>
/// <remarks>
/// This helper method is made available for query operator authors in order to discover scheduler services by using the required
/// IServiceProvider pattern, which allows for interception or redefinition of scheduler services.
/// </remarks>
public static ISchedulerLongRunning? AsLongRunning(this IScheduler scheduler) => As<ISchedulerLongRunning>(scheduler);
/// <summary>
/// Returns the <see cref="IStopwatchProvider"/> implementation of the specified scheduler, or <c>null</c> if no such implementation is available.
/// </summary>
/// <param name="scheduler">Scheduler to get the <see cref="IStopwatchProvider"/> implementation for.</param>
/// <returns>The scheduler's <see cref="IStopwatchProvider"/> implementation if available; <c>null</c> otherwise.</returns>
/// <remarks>
/// <para>
/// This helper method is made available for query operator authors in order to discover scheduler services by using the required
/// IServiceProvider pattern, which allows for interception or redefinition of scheduler services.
/// </para>
/// <para>
/// Consider using <see cref="StartStopwatch"/> in case a stopwatch is required, but use of emulation stopwatch based
/// on the scheduler's clock is acceptable. Use of this method is recommended for best-effort use of the stopwatch provider
/// scheduler service, where the caller falls back to not using stopwatches if this facility wasn't found.
/// </para>
/// </remarks>
public static IStopwatchProvider? AsStopwatchProvider(this IScheduler scheduler) => As<IStopwatchProvider>(scheduler);
/// <summary>
/// Returns the <see cref="ISchedulerPeriodic"/> implementation of the specified scheduler, or <c>null</c> if no such implementation is available.
/// </summary>
/// <param name="scheduler">Scheduler to get the <see cref="ISchedulerPeriodic"/> implementation for.</param>
/// <returns>The scheduler's <see cref="ISchedulerPeriodic"/> implementation if available; <c>null</c> otherwise.</returns>
/// <remarks>
/// <para>
/// This helper method is made available for query operator authors in order to discover scheduler services by using the required
/// IServiceProvider pattern, which allows for interception or redefinition of scheduler services.
/// </para>
/// <para>
/// Consider using the <see cref="SchedulePeriodic"/> extension methods for <see cref="IScheduler"/> in case periodic scheduling
/// is required and emulation of periodic behavior using other scheduler services is desirable. Use of this method is recommended
/// for best-effort use of the periodic scheduling service, where the caller falls back to not using periodic scheduling if this
/// facility wasn't found.
/// </para>
/// </remarks>
public static ISchedulerPeriodic? AsPeriodic(this IScheduler scheduler) => As<ISchedulerPeriodic>(scheduler);
private static T? As<T>(IScheduler scheduler)
where T : class
{
if (scheduler is IServiceProvider svc)
{
return (T?)svc.GetService(typeof(T));
}
return null;
}
}
}