// By design, the code is mostly duplicated between the async and sync calls.
// Async retry
internal static Func <TRequest, CallSettings, Task <TResponse> > WithRetry <TRequest, TResponse>(
this Func <TRequest, CallSettings, Task <TResponse> > fn,
IClock clock, IScheduler scheduler, Func <TResponse, Task> postResponse) =>
async(request, callSettings) =>
{
RetrySettings retrySettings = callSettings.Retry;
if (retrySettings == null)
{
return(await fn(request, callSettings).ConfigureAwait(false));
}
DateTime?overallDeadline = callSettings.Expiration.CalculateDeadline(clock);
// Every attempt should use the same deadline, calculated from the start of the call.
if (callSettings.Expiration?.Type == ExpirationType.Timeout)
{
callSettings = callSettings.WithDeadline(overallDeadline.Value);
}
TimeSpan backoffDelay = retrySettings.InitialBackoff;
int attempt = 0;
while (true)
{
try
{
attempt++;
var response = await fn(request, callSettings).ConfigureAwait(false);
if (postResponse != null)
{
await postResponse(response).ConfigureAwait(false);
}
return(response);
}
catch (RpcException e) when(attempt < retrySettings.MaxAttempts && retrySettings.RetryFilter(e))
{
TimeSpan actualDelay = retrySettings.BackoffJitter.GetDelay(backoffDelay);
DateTime expectedRetryTime = clock.GetCurrentDateTimeUtc() + actualDelay;
if (expectedRetryTime > overallDeadline)
{
throw;
}
await scheduler.Delay(actualDelay, callSettings.CancellationToken.GetValueOrDefault()).ConfigureAwait(false);
backoffDelay = retrySettings.NextBackoff(backoffDelay);
}
}
};
// By design, the code is mostly duplicated between the async and sync calls.
// Async retry
internal static Func <TRequest, CallSettings, Task <TResponse> > WithRetry <TRequest, TResponse>(
this Func <TRequest, CallSettings, Task <TResponse> > fn,
IClock clock, IScheduler scheduler, Func <TResponse, Task> postResponse) =>
async(request, callSettings) =>
{
RetrySettings retrySettings = callSettings.Timing?.Retry;
if (retrySettings == null)
{
return(await fn(request, callSettings).ConfigureAwait(false));
}
DateTime?overallDeadline = retrySettings.TotalExpiration.CalculateDeadline(clock);
TimeSpan retryDelay = retrySettings.RetryBackoff.Delay;
TimeSpan callTimeout = retrySettings.TimeoutBackoff.Delay;
while (true)
{
DateTime attemptDeadline = clock.GetCurrentDateTimeUtc() + callTimeout;
// Note: this handles a null total deadline due to "<" returning false if overallDeadline is null.
DateTime combinedDeadline = overallDeadline < attemptDeadline ? overallDeadline.Value : attemptDeadline;
CallSettings attemptCallSettings = callSettings.WithCallTiming(CallTiming.FromDeadline(combinedDeadline));
try
{
var response = await fn(request, attemptCallSettings).ConfigureAwait(false);
if (postResponse != null)
{
await postResponse(response).ConfigureAwait(false);
}
return(response);
}
catch (RpcException e) when(retrySettings.RetryFilter(e))
{
TimeSpan actualDelay = retrySettings.DelayJitter.GetDelay(retryDelay);
DateTime expectedRetryTime = clock.GetCurrentDateTimeUtc() + actualDelay;
if (expectedRetryTime > overallDeadline)
{
throw;
}
await scheduler.Delay(actualDelay, callSettings.CancellationToken.GetValueOrDefault()).ConfigureAwait(false);
retryDelay = retrySettings.RetryBackoff.NextDelay(retryDelay);
callTimeout = retrySettings.TimeoutBackoff.NextDelay(callTimeout);
}
}
};