/// <summary>
/// Occurs when the server returns an error code of 500 or higher.
/// </summary>
/// <param name="e">Arguments for the event.</param>
protected virtual void OnServerError(RetryEventArgs e)
{
ServerError?.Invoke(this, e);
}
/// <summary>
/// Occurs when a request fails because the rate limit has been exceeded (status code 429).
/// </summary>
/// <param name="e">Arguments for the event.</param>
protected virtual void OnRateLimitExceeded(RetryEventArgs e)
{
RateLimitExceeded?.Invoke(this, e);
}
/// <summary>
/// Occurs when the client fails to connect to the server while executing a request.
/// </summary>
/// <param name="e">Arguments for the event.</param>
protected virtual void OnConnectionFailed(RetryEventArgs e)
{
ConnectionFailed?.Invoke(this, e);
}
/// <summary>
/// Occurs when a request times out.
/// </summary>
/// <param name="e">Arguments for the event.</param>
protected virtual void OnRequestTimedOut(RetryEventArgs e)
{
RequestTimedOut?.Invoke(this, e);
}
/// <summary>
/// Determines which action to take for the given response.
/// </summary>
/// <param name="response">An <see cref="HttpResponseMessage"/>.</param>
/// <param name="attemptCount">The number of times the request has been attempted so far.</param>
/// <param name="token">The cancellation token to cancel the operation.</param>
/// <returns>A <see cref="ResponseAction"/>.</returns>
protected virtual async Task <ResponseAction> DetermineResponseAction(RiotResponse response, int attemptCount, CancellationToken token)
{
if (response.TimedOut)
{
var args = new RetryEventArgs(response, attemptCount)
{
Retry = Settings.RetryOnTimeout
};
OnRequestTimedOut(args);
// Note: never retry if the token is cancelled. It will certainly fail the next time, too.
if (args.Retry && !token.IsCancellationRequested)
{
return(ResponseAction.Retry);
}
if (Settings.ThrowOnError)
{
throw new RestTimeoutException(response, response.Exception);
}
return(ResponseAction.ReturnDefault);
}
if (response.Response == null)
{
var args = new RetryEventArgs(response, attemptCount)
{
Retry = Settings.RetryOnConnectionFailure
};
OnConnectionFailed(args);
if (args.Retry)
{
return(ResponseAction.Retry);
}
if (Settings.ThrowOnError)
{
throw new ConnectionFailedException(response, response.Exception);
}
return(ResponseAction.ReturnDefault);
}
var statusCode = (int)response.Response.StatusCode;
if (statusCode == 429)
{
var args = new RetryEventArgs(response, attemptCount)
{
Retry = Settings.RetryOnRateLimitExceeded
};
OnRateLimitExceeded(args);
if (args.Retry)
{
return(ResponseAction.Retry);
}
if (Settings.ThrowOnError)
{
throw new RateLimitExceededException(response);
}
return(ResponseAction.ReturnDefault);
}
if (statusCode == 404)
{
OnResourceNotFound(new ResponseEventArgs(response));
if (Settings.ThrowOnNotFound)
{
throw new NotFoundException(response);
}
return(ResponseAction.ReturnDefault);
}
if (statusCode >= 500)
{
var args = new RetryEventArgs(response, attemptCount)
{
Retry = Settings.RetryOnServerError
};
OnServerError(args);
if (args.Retry)
{
return(ResponseAction.Retry);
}
if (Settings.ThrowOnError)
{
var message = await GetServerErrorMessage(response).ConfigureAwait(false);
if (message != null)
{
throw new RestException(response, message);
}
else
{
throw new RestException(response);
}
}
return(ResponseAction.ReturnDefault);
}
if (statusCode >= 400)
{
var message = await GetServerErrorMessage(response).ConfigureAwait(false);
OnResponseError(new ResponseEventArgs(response, message));
if (Settings.ThrowOnError)
{
if (message != null)
{
throw new RestException(response, message, response.Exception);
}
else
{
throw new RestException(response, response.Exception);
}
}
return(ResponseAction.ReturnDefault);
}
return(ResponseAction.Return);
}
/// <summary>
/// Sends a request.
/// </summary>
/// <param name="request">The request to send.</param>
/// <param name="methodName">The name of the method being executed (for rate limiting purposes).</param>
/// <param name="platformId">The platform ID corresponding to the server. This should equal one of the <see cref="Models.PlatformId"/> values.</param>
/// <param name="token">The cancellation token to cancel the operation.</param>
/// <returns>A task that represents the asynchronous operation.</returns>
protected async Task <RiotResponse> SendAsync(HttpRequestMessage request, string methodName, string platformId, CancellationToken token)
{
DateTime targetTime = DateTime.UtcNow;
if (retryAfterTimes.TryGetValue(platformId, out DateTime retryAfter) && retryAfter > targetTime)
{
targetTime = retryAfter;
}
if (rateLimiter != null)
{
var limiterDelayTime = rateLimiter.AddRequestOrGetDelay(methodName, platformId);
if (limiterDelayTime > targetTime)
{
targetTime = limiterDelayTime;
}
}
if (targetTime <= DateTime.UtcNow)
{
try
{
var response = await client.SendAsync(request, token).ConfigureAwait(false);
return(new RiotResponse(response));
}
catch (TaskCanceledException ex)
{
return(new RiotResponse(null, ex, true));
}
catch (Exception ex)
{
return(new RiotResponse(null, ex));
}
}
else
{
// We need to throttle. Add requests to a queue to ensure that they are processed in order, so one request doesn't get starved.
var args = new RetryEventArgs(null, 1)
{
Retry = Settings.RetryOnRateLimitExceeded
};
OnRateLimitExceeded(args);
if (!args.Retry)
{
if (Settings.ThrowOnError)
{
throw new RateLimitExceededException();
}
return(null);
}
// Create a task to re-send but DON'T start it until targetTime.
var task = new Task <Task <RiotResponse> >(() => SendAsync(request, methodName, platformId, token), token);
ConcurrentQueue <Task <Task <RiotResponse> > > addedQueue = null;
var queue = throttledRequestQueues.GetOrAdd(targetTime, (dt) =>
{
return(addedQueue = new ConcurrentQueue <Task <Task <RiotResponse> > >());
});
queue.Enqueue(task);
// Checking that addedQueue == queue is the only way to guarantee that the new queue was really added.
// According to Microsoft docs: "If you call GetOrAdd simultaneously on different threads, addValueFactory may be called multiple times,
// but its key/value pair might not be added to the dictionary for every call."
if (addedQueue == queue)
{
ProcessRequestQueue(targetTime);
}
return(await await task);
}
}
