ClientRetryPolicy
using Microsoft.Extensions.Logging;
using System.ClientModel.Internal;
using System.Collections.Generic;
using System.Runtime.CompilerServices;
using System.Threading;
using System.Threading.Tasks;
namespace System.ClientModel.Primitives
{
    [System.Runtime.CompilerServices.NullableContext(1)]
    [System.Runtime.CompilerServices.Nullable(0)]
    public class ClientRetryPolicy : PipelinePolicy
    {
        private static readonly TimeSpan DefaultInitialDelay = TimeSpan.FromSeconds(0.8);
        private readonly int _maxRetries;
        private readonly TimeSpan _initialDelay;
        [System.Runtime.CompilerServices.Nullable(2)]
        private readonly PipelineRetryLogger _retryLogger;
        internal const int DefaultMaxRetries = 3;
        public static ClientRetryPolicy Default { get; } = new ClientRetryPolicy(3);
        public ClientRetryPolicy(int maxRetries = 3)
            : this(maxRetries, true, null)
        {
        }
        [System.Runtime.CompilerServices.NullableContext(2)]
        public ClientRetryPolicy(int maxRetries, bool enableLogging, ILoggerFactory loggerFactory)
        {
            _maxRetries = maxRetries;
            _initialDelay = DefaultInitialDelay;
            _retryLogger = (enableLogging ? new PipelineRetryLogger(loggerFactory) : null);
        }
        public sealed override void Process(PipelineMessage message, IReadOnlyList<PipelinePolicy> pipeline, int currentIndex)
        {
            ProcessSyncOrAsync(message, pipeline, currentIndex, false).EnsureCompleted();
        }
        [AsyncStateMachine(typeof(<ProcessAsync>d__11))]
        public sealed override ValueTask ProcessAsync(PipelineMessage message, IReadOnlyList<PipelinePolicy> pipeline, int currentIndex)
        {
            <ProcessAsync>d__11 stateMachine = default(<ProcessAsync>d__11);
            stateMachine.<>t__builder = AsyncValueTaskMethodBuilder.Create();
            stateMachine.<>4__this = this;
            stateMachine.message = message;
            stateMachine.pipeline = pipeline;
            stateMachine.currentIndex = currentIndex;
            stateMachine.<>1__state = -1;
            stateMachine.<>t__builder.Start(ref stateMachine);
            return stateMachine.<>t__builder.Task;
        }
        [AsyncStateMachine(typeof(<ProcessSyncOrAsync>d__12))]
        private ValueTask ProcessSyncOrAsync(PipelineMessage message, IReadOnlyList<PipelinePolicy> pipeline, int currentIndex, bool async)
        {
            <ProcessSyncOrAsync>d__12 stateMachine = default(<ProcessSyncOrAsync>d__12);
            stateMachine.<>t__builder = AsyncValueTaskMethodBuilder.Create();
            stateMachine.<>4__this = this;
            stateMachine.message = message;
            stateMachine.pipeline = pipeline;
            stateMachine.currentIndex = currentIndex;
            stateMachine.async = async;
            stateMachine.<>1__state = -1;
            stateMachine.<>t__builder.Start(ref stateMachine);
            return stateMachine.<>t__builder.Task;
        }
        protected virtual void OnSendingRequest(PipelineMessage message)
        {
        }
        protected virtual ValueTask OnSendingRequestAsync(PipelineMessage message)
        {
            return default(ValueTask);
        }
        protected virtual void OnRequestSent(PipelineMessage message)
        {
        }
        protected virtual ValueTask OnRequestSentAsync(PipelineMessage message)
        {
            return default(ValueTask);
        }
        protected virtual void OnTryComplete(PipelineMessage message)
        {
        }
        internal bool ShouldRetryInternal(PipelineMessage message, [System.Runtime.CompilerServices.Nullable(2)] Exception exception)
        {
            return ShouldRetryInternalSyncOrAsync(message, exception, false).EnsureCompleted();
        }
        [System.Runtime.CompilerServices.NullableContext(0)]
        [AsyncStateMachine(typeof(<ShouldRetryInternalAsync>d__19))]
        internal ValueTask<bool> ShouldRetryInternalAsync([System.Runtime.CompilerServices.Nullable(1)] PipelineMessage message, [System.Runtime.CompilerServices.Nullable(2)] Exception exception)
        {
            <ShouldRetryInternalAsync>d__19 stateMachine = default(<ShouldRetryInternalAsync>d__19);
            stateMachine.<>t__builder = AsyncValueTaskMethodBuilder<bool>.Create();
            stateMachine.<>4__this = this;
            stateMachine.message = message;
            stateMachine.exception = exception;
            stateMachine.<>1__state = -1;
            stateMachine.<>t__builder.Start(ref stateMachine);
            return stateMachine.<>t__builder.Task;
        }
        [System.Runtime.CompilerServices.NullableContext(0)]
        [AsyncStateMachine(typeof(<ShouldRetryInternalSyncOrAsync>d__20))]
        private ValueTask<bool> ShouldRetryInternalSyncOrAsync([System.Runtime.CompilerServices.Nullable(1)] PipelineMessage message, [System.Runtime.CompilerServices.Nullable(2)] Exception exception, bool async)
        {
            <ShouldRetryInternalSyncOrAsync>d__20 stateMachine = default(<ShouldRetryInternalSyncOrAsync>d__20);
            stateMachine.<>t__builder = AsyncValueTaskMethodBuilder<bool>.Create();
            stateMachine.<>4__this = this;
            stateMachine.message = message;
            stateMachine.exception = exception;
            stateMachine.async = async;
            stateMachine.<>1__state = -1;
            stateMachine.<>t__builder.Start(ref stateMachine);
            return stateMachine.<>t__builder.Task;
        }
        protected virtual bool ShouldRetry(PipelineMessage message, [System.Runtime.CompilerServices.Nullable(2)] Exception exception)
        {
            if (message.RetryCount >= _maxRetries)
                return false;
            if (!message.ResponseClassifier.TryClassify(message, exception, out bool isRetriable))
                PipelineMessageClassifier.Default.TryClassify(message, exception, out isRetriable);
            return isRetriable;
        }
        [System.Runtime.CompilerServices.NullableContext(0)]
        protected virtual ValueTask<bool> ShouldRetryAsync([System.Runtime.CompilerServices.Nullable(1)] PipelineMessage message, [System.Runtime.CompilerServices.Nullable(2)] Exception exception)
        {
            return new ValueTask<bool>(ShouldRetry(message, exception));
        }
        protected virtual TimeSpan GetNextDelay(PipelineMessage message, int tryCount)
        {
            double num = (double)(1 << tryCount - 1) * _initialDelay.TotalMilliseconds;
            TimeSpan value;
            if (message.Response != null && PipelineResponseHeaders.TryGetRetryAfter(message.Response, out value) && value.TotalMilliseconds > num)
                return value;
            return TimeSpan.FromMilliseconds(num);
        }
        [AsyncStateMachine(typeof(<WaitAsync>d__24))]
        protected virtual Task WaitAsync(TimeSpan time, CancellationToken cancellationToken)
        {
            <WaitAsync>d__24 stateMachine = default(<WaitAsync>d__24);
            stateMachine.<>t__builder = AsyncTaskMethodBuilder.Create();
            stateMachine.time = time;
            stateMachine.cancellationToken = cancellationToken;
            stateMachine.<>1__state = -1;
            stateMachine.<>t__builder.Start(ref stateMachine);
            return stateMachine.<>t__builder.Task;
        }
        protected virtual void Wait(TimeSpan time, CancellationToken cancellationToken)
        {
            if (cancellationToken.WaitHandle.WaitOne(time))
                CancellationHelper.ThrowIfCancellationRequested(cancellationToken, null);
        }
    }
}