private async Task <TResult> TryExecuteAsync <TResult>(Func <Task <TResult> > funcToThrottle)
{
await this.WaitIfNeededAsync();
var result = await funcToThrottle();
TrueShipLogger.Log().Debug("Throttler: request executed successfully");
this.SubtractQuota();
return(result);
}
private async void SubtractQuota()
{
await this.semaphore.WaitAsync();
try
{
this._remainingQuota--;
if (this._remainingQuota < 0)
{
this._remainingQuota = 0;
}
}
finally
{
this.semaphore.Release();
}
this._requestTimer.Start();
TrueShipLogger.Log().Debug("Throttler: substracted quota, now available {0}", this._remainingQuota);
}
private async Task WaitIfNeededAsync()
{
await this.semaphore.WaitAsync();
try
{
this.UpdateRequestQuoteFromTimer();
if (this._remainingQuota != 0)
{
return;
}
}
finally
{
this.semaphore.Release();
}
TrueShipLogger.Log().Debug("Throttler: quota exceeded. Waiting...");
await this._delay();
}
public async Task <TResult> ExecuteAsync <TResult>(Func <Task <TResult> > funcToThrottle)
{
var retryCount = 0;
while (true)
{
var shouldWait = false;
try
{
TrueShipLogger.Log().Debug("Throttler: trying execute request for the {0} time", retryCount);
return(await this.TryExecuteAsync(funcToThrottle).ConfigureAwait(false));
}
catch (Exception ex)
{
if (!this.IsExceptionFromThrottling(ex))
{
throw;
}
if (retryCount >= this._maxRetryCount)
{
throw new ThrottlerException("Throttle max retry count reached", ex);
}
TrueShipLogger.Log().Debug("Throttler: got throttling exception. Retrying...");
this._remainingQuota = 0;
this._requestTimer.Restart();
shouldWait = true;
retryCount++;
// try again through loop
}
if (shouldWait)
{
TrueShipLogger.Log().Debug("Throttler: waiting before next retry...");
await this._delay();
}
}
}
private void UpdateRequestQuoteFromTimer()
{
if (!this._requestTimer.IsRunning || this._remainingQuota == this._maxQuota)
{
return;
}
var totalSeconds = this._requestTimer.Elapsed.TotalSeconds;
var elapsed = ( int )Math.Floor(totalSeconds);
var quotaReleased = this._releasedQuotaCalculator(elapsed);
TrueShipLogger.Log().Debug("Throttler: {0} seconds elapsed, quota released: {1}", elapsed, quotaReleased);
if (quotaReleased == 0)
{
return;
}
this._remainingQuota = Math.Min(this._remainingQuota + quotaReleased, this._maxQuota);
TrueShipLogger.Log().Debug("Throttler: added quota, now available {0}", this._remainingQuota);
this._requestTimer.Reset();
}