AsyncDelayer.cs

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using System;
using System.Diagnostics;
using System.Threading;
using System.Threading.Tasks;
 
using Microsoft.Extensions.Logging;
 
namespace Tgstation.Server.Host.Utils
{
    sealed class AsyncDelayer : IAsyncDelayer
    {
        readonly ILogger<AsyncDelayer> logger;
 
        public AsyncDelayer(ILogger<AsyncDelayer> logger)
        {
            this.logger = logger ?? throw new ArgumentNullException(nameof(logger));
        }
 
        public async ValueTask Delay(TimeSpan timeSpan, CancellationToken cancellationToken)
        {
            // https://learn.microsoft.com/en-us/dotnet/api/system.threading.tasks.task.delay?view=net-8.0#system-threading-tasks-task-delay(system-timespan)
            const uint DelayMinutesLimit = UInt32.MaxValue - 1;
            Debug.Assert(DelayMinutesLimit == 4294967294, "Delay limit assertion failure!");
 
            var maxDelayIterations = 0UL;
            if (timeSpan.TotalMilliseconds >= UInt32.MaxValue)
            {
                maxDelayIterations = (ulong)Math.Floor(timeSpan.TotalMilliseconds / DelayMinutesLimit);
                logger.LogDebug("Breaking interval into {iterationCount} iterations", maxDelayIterations + 1);
                timeSpan = TimeSpan.FromMilliseconds(timeSpan.TotalMilliseconds - (maxDelayIterations * DelayMinutesLimit));
            }
 
            if (maxDelayIterations > 0)
            {
                var longDelayTimeSpan = TimeSpan.FromMilliseconds(DelayMinutesLimit);
                for (var i = 0UL; i < maxDelayIterations; ++i)
                {
                    logger.LogTrace("Long delay #{iteration}...", i + 1);
                    await Task.Delay(longDelayTimeSpan, cancellationToken);
                }
 
                logger.LogTrace("Final delay iteration #{iteration}...", maxDelayIterations + 1);
            }
 
            await Task.Delay(timeSpan, cancellationToken);
        }
    }
}