private void UpdateBucket(BaseRestRequest request, RestResponse response, TaskCompletionSource <bool> ratelimitTcs)
{
var bucket = request.RateLimitBucket;
if (response.Headers == null)
{
if (response.ResponseCode != 429) // do not fail when ratelimit was or the next request will be scheduled hitting the rate limit again
{
this.FailInitialRateLimitTest(request, ratelimitTcs);
}
return;
}
var hs = response.Headers;
if (hs.TryGetValue("X-RateLimit-Global", out var isglobal) && isglobal.ToLowerInvariant() == "true")
{
if (response.ResponseCode != 429)
{
this.FailInitialRateLimitTest(request, ratelimitTcs);
}
return;
}
var r1 = hs.TryGetValue("X-RateLimit-Limit", out var usesmax);
var r2 = hs.TryGetValue("X-RateLimit-Remaining", out var usesleft);
var r3 = hs.TryGetValue("X-RateLimit-Reset", out var reset);
var r4 = hs.TryGetValue("X-Ratelimit-Reset-After", out var resetAfter);
var r5 = hs.TryGetValue("X-Ratelimit-Bucket", out var hash);
if (!r1 || !r2 || !r3 || !r4)
{
//If the limits were determined before this request, make the bucket initial again.
if (response.ResponseCode != 429)
{
this.FailInitialRateLimitTest(request, ratelimitTcs, ratelimitTcs == null);
}
return;
}
var clienttime = DateTimeOffset.UtcNow;
var resettime = new DateTimeOffset(1970, 1, 1, 0, 0, 0, TimeSpan.Zero).AddSeconds(double.Parse(reset, CultureInfo.InvariantCulture));
var servertime = clienttime;
if (hs.TryGetValue("Date", out var raw_date))
{
servertime = DateTimeOffset.Parse(raw_date, CultureInfo.InvariantCulture).ToUniversalTime();
}
var resetdelta = resettime - servertime;
//var difference = clienttime - servertime;
//if (Math.Abs(difference.TotalSeconds) >= 1)
//// this.Logger.LogMessage(LogLevel.DebugBaseDiscordClient.RestEventId, $"Difference between machine and server time: {difference.TotalMilliseconds.ToString("#,##0.00", CultureInfo.InvariantCulture)}ms", DateTime.Now);
//else
// difference = TimeSpan.Zero;
if (request.RateLimitWaitOverride.HasValue)
{
resetdelta = TimeSpan.FromSeconds(request.RateLimitWaitOverride.Value);
}
var newReset = clienttime + resetdelta;
if (this.UseResetAfter)
{
bucket.ResetAfter = TimeSpan.FromSeconds(double.Parse(resetAfter, CultureInfo.InvariantCulture));
newReset = clienttime + bucket.ResetAfter.Value + (request.RateLimitWaitOverride.HasValue
? resetdelta
: TimeSpan.Zero);
bucket._resetAfterOffset = newReset;
}
else
{
bucket.Reset = newReset;
}
var maximum = int.Parse(usesmax, CultureInfo.InvariantCulture);
var remaining = int.Parse(usesleft, CultureInfo.InvariantCulture);
if (ratelimitTcs != null)
{
// initial population of the ratelimit data
bucket.SetInitialValues(maximum, remaining, newReset);
_ = Task.Run(() => ratelimitTcs.TrySetResult(true));
}
else
{
// only update the bucket values if this request was for a newer interval than the one
// currently in the bucket, to avoid issues with concurrent requests in one bucket
// remaining is reset by TryResetLimit and not the response, just allow that to happen when it is time
if (bucket._nextReset == 0)
{
bucket._nextReset = newReset.UtcTicks;
}
}
this.UpdateHashCaches(request, bucket, hash);
}
// to allow proper rescheduling of the first request from a bucket
private async Task ExecuteRequestAsync(BaseRestRequest request, RateLimitBucket bucket, TaskCompletionSource <bool> ratelimitTcs)
{
if (this._disposed)
{
return;
}
HttpResponseMessage res = default;
try
{
await this.GlobalRateLimitEvent.WaitAsync().ConfigureAwait(false);
if (bucket == null)
{
bucket = request.RateLimitBucket;
}
if (ratelimitTcs == null)
{
ratelimitTcs = await this.WaitForInitialRateLimit(bucket).ConfigureAwait(false);
}
if (ratelimitTcs == null) // ckeck rate limit only if we are not the probe request
{
var now = DateTimeOffset.UtcNow;
await bucket.TryResetLimitAsync(now).ConfigureAwait(false);
// Decrement the remaining number of requests as there can be other concurrent requests before this one finishes and has a chance to update the bucket
#pragma warning disable 420 // interlocked access is always volatile
if (Interlocked.Decrement(ref bucket._remaining) < 0)
#pragma warning restore 420 // blaze it
{
this.Logger.LogDebug(LoggerEvents.RatelimitDiag, "Request for {0} is blocked", bucket.ToString());
var delay = bucket.Reset - now;
var resetDate = bucket.Reset;
if (this.UseResetAfter)
{
delay = bucket.ResetAfter.Value;
resetDate = bucket._resetAfterOffset;
}
if (delay < new TimeSpan(-TimeSpan.TicksPerMinute))
{
this.Logger.LogError(LoggerEvents.RatelimitDiag, "Failed to retrieve ratelimits - giving up and allowing next request for bucket");
bucket._remaining = 1;
}
if (delay < TimeSpan.Zero)
{
delay = TimeSpan.FromMilliseconds(100);
}
this.Logger.LogWarning(LoggerEvents.RatelimitPreemptive, "Pre-emptive ratelimit triggered - waiting until {0:yyyy-MM-dd HH:mm:ss zzz} ({1:c}).", resetDate, delay);
Task.Delay(delay)
.ContinueWith(_ => this.ExecuteRequestAsync(request, null, null))
.LogTaskFault(this.Logger, LogLevel.Error, LoggerEvents.RestError, "Error while executing request");
return;
}
this.Logger.LogDebug(LoggerEvents.RatelimitDiag, "Request for {0} is allowed", bucket.ToString());
}
else
{
this.Logger.LogDebug(LoggerEvents.RatelimitDiag, "Initial request for {0} is allowed", bucket.ToString());
}
var req = this.BuildRequest(request);
var response = new RestResponse();
try
{
if (this._disposed)
{
return;
}
res = await HttpClient.SendAsync(req, HttpCompletionOption.ResponseContentRead, CancellationToken.None).ConfigureAwait(false);
var bts = await res.Content.ReadAsByteArrayAsync().ConfigureAwait(false);
var txt = Utilities.UTF8.GetString(bts, 0, bts.Length);
this.Logger.LogTrace(LoggerEvents.RestRx, txt);
response.Headers = res.Headers.ToDictionary(xh => xh.Key, xh => string.Join("\n", xh.Value), StringComparer.OrdinalIgnoreCase);
response.Response = txt;
response.ResponseCode = (int)res.StatusCode;
}
catch (HttpRequestException httpex)
{
this.Logger.LogError(LoggerEvents.RestError, httpex, "Request to {0} triggered an HttpException", request.Url);
request.SetFaulted(httpex);
this.FailInitialRateLimitTest(request, ratelimitTcs);
return;
}
this.UpdateBucket(request, response, ratelimitTcs);
Exception ex = null;
switch (response.ResponseCode)
{
case 400:
case 405:
ex = new BadRequestException(request, response);
break;
case 401:
case 403:
ex = new UnauthorizedException(request, response);
break;
case 404:
ex = new NotFoundException(request, response);
break;
case 413:
ex = new RequestSizeException(request, response);
break;
case 429:
ex = new RateLimitException(request, response);
// check the limit info and requeue
this.Handle429(response, out var wait, out var global);
if (wait != null)
{
if (global)
{
this.Logger.LogError(LoggerEvents.RatelimitHit, "Global ratelimit hit, cooling down");
try
{
this.GlobalRateLimitEvent.Reset();
await wait.ConfigureAwait(false);
}
finally
{
// we don't want to wait here until all the blocked requests have been run, additionally Set can never throw an exception that could be suppressed here
_ = this.GlobalRateLimitEvent.SetAsync();
}
this.ExecuteRequestAsync(request, bucket, ratelimitTcs)
.LogTaskFault(this.Logger, LogLevel.Error, LoggerEvents.RestError, "Error while retrying request");
}
else
{
this.Logger.LogError(LoggerEvents.RatelimitHit, "Ratelimit hit, requeueing request to {0}", request.Url);
await wait.ConfigureAwait(false);
this.ExecuteRequestAsync(request, bucket, ratelimitTcs)
.LogTaskFault(this.Logger, LogLevel.Error, LoggerEvents.RestError, "Error while retrying request");
}
return;
}
break;
case 500:
case 502:
case 503:
case 504:
ex = new ServerErrorException(request, response);
break;
}
if (ex != null)
{
request.SetFaulted(ex);
}
else
{
request.SetCompleted(response);
}
}
catch (Exception ex)
{
this.Logger.LogError(LoggerEvents.RestError, ex, "Request to {0} triggered an exception", request.Url);
// if something went wrong and we couldn't get rate limits for the first request here, allow the next request to run
if (bucket != null && ratelimitTcs != null && bucket._limitTesting != 0)
{
this.FailInitialRateLimitTest(request, ratelimitTcs);
}
if (!request.TrySetFaulted(ex))
{
throw;
}
}
finally
{
res?.Dispose();
// Get and decrement active requests in this bucket by 1.
_ = this.RequestQueue.TryGetValue(bucket.BucketId, out var count);
this.RequestQueue[bucket.BucketId] = Interlocked.Decrement(ref count);
// If it's 0 or less, we can remove the bucket from the active request queue,
// along with any of its past routes.
if (count <= 0)
{
foreach (var r in bucket.RouteHashes)
{
if (this.RequestQueue.ContainsKey(r))
{
_ = this.RequestQueue.TryRemove(r, out _);
}
}
}
}
}
protected internal void SetCompleted(RestResponse response) => this.RequestTaskSource.SetResult(response);
// to allow proper rescheduling of the first request from a bucket
private async Task ExecuteRequestAsync(BaseRestRequest request, RateLimitBucket bucket, TaskCompletionSource <bool> ratelimitTcs)
{
try
{
await this.GlobalRateLimitEvent.WaitAsync();
if (bucket == null)
{
bucket = request.RateLimitBucket;
}
if (ratelimitTcs == null)
{
ratelimitTcs = await this.WaitForInitialRateLimit(bucket);
}
if (ratelimitTcs == null) // ckeck rate limit only if we are not the probe request
{
var now = DateTimeOffset.UtcNow;
await bucket.TryResetLimit(now);
// Decrement the remaining number of requests as there can be other concurrent requests before this one finishes and has a chance to update the bucket
#pragma warning disable 420 // interlocked access is always volatile
if (Interlocked.Decrement(ref bucket._remaining) < 0)
#pragma warning restore 420
{
request.Discord.DebugLogger.LogMessage(LogLevel.Debug, "REST", $"Request for bucket {bucket}. Blocking.", DateTime.Now);
var delay = bucket.Reset - now;
if (delay < new TimeSpan(-TimeSpan.TicksPerMinute))
{
request.Discord.DebugLogger.LogMessage(LogLevel.Error, "REST", "Failed to retrieve ratelimits. Giving up and allowing next request for bucket.", DateTime.Now);
bucket._remaining = 1;
}
if (delay < TimeSpan.Zero)
{
delay = TimeSpan.FromMilliseconds(100);
}
request.Discord.DebugLogger.LogMessage(LogLevel.Warning, "REST", $"Pre-emptive ratelimit triggered, waiting until {bucket.Reset:yyyy-MM-dd HH:mm:ss zzz} ({delay:c})", DateTime.Now);
request.Discord.DebugLogger.LogTaskFault(Task.Delay(delay).ContinueWith(t => this.ExecuteRequestAsync(request, null, null)), LogLevel.Error, "RESET", "Error while executing request: ");
return;
}
request.Discord.DebugLogger.LogMessage(LogLevel.Debug, "REST", $"Request for bucket {bucket}. Allowing.", DateTime.Now);
}
else
{
request.Discord.DebugLogger.LogMessage(LogLevel.Debug, "REST", $"Initial Request for bucket {bucket}. Allowing.", DateTime.Now);
}
var req = this.BuildRequest(request);
var response = new RestResponse();
try
{
var res = await HttpClient.SendAsync(req, CancellationToken.None).ConfigureAwait(false);
var bts = await res.Content.ReadAsByteArrayAsync().ConfigureAwait(false);
var txt = UTF8.GetString(bts, 0, bts.Length);
response.Headers = res.Headers.ToDictionary(xh => xh.Key, xh => string.Join("\n", xh.Value));
response.Response = txt;
response.ResponseCode = (int)res.StatusCode;
}
catch (HttpRequestException httpex)
{
request.Discord.DebugLogger.LogMessage(LogLevel.Error, "REST", $"Request to {request.Url} triggered an HttpException: {httpex.Message}", DateTime.Now);
request.SetFaulted(httpex);
this.FailInitialRateLimitTest(bucket, ratelimitTcs);
return;
}
this.UpdateBucket(request, response, ratelimitTcs);
Exception ex = null;
switch (response.ResponseCode)
{
case 400:
case 405:
ex = new BadRequestException(request, response);
break;
case 401:
case 403:
ex = new UnauthorizedException(request, response);
break;
case 404:
ex = new NotFoundException(request, response);
break;
case 429:
ex = new RateLimitException(request, response);
// check the limit info and requeue
this.Handle429(response, out var wait, out var global);
if (wait != null)
{
if (global)
{
request.Discord.DebugLogger.LogMessage(LogLevel.Error, "REST", "Global ratelimit hit, cooling down", DateTime.Now);
try
{
this.GlobalRateLimitEvent.Reset();
await wait.ConfigureAwait(false);
}
finally
{
// we don't want to wait here until all the blocked requests have been run, additionally Set can never throw an exception that could be suppressed here
_ = this.GlobalRateLimitEvent.Set();
}
request.Discord.DebugLogger.LogTaskFault(ExecuteRequestAsync(request, bucket, ratelimitTcs), LogLevel.Error, "REST", "Error while retrying request: ");
}
else
{
request.Discord.DebugLogger.LogMessage(LogLevel.Error, "REST", $"Ratelimit hit, requeueing request to {request.Url}", DateTime.Now);
await wait.ConfigureAwait(false);
request.Discord.DebugLogger.LogTaskFault(this.ExecuteRequestAsync(request, bucket, ratelimitTcs), LogLevel.Error, "REST", "Error while retrying request: ");
}
return;
}
break;
}
if (ex != null)
{
request.SetFaulted(ex);
}
else
{
request.SetCompleted(response);
}
}
catch (Exception ex)
{
request.Discord.DebugLogger.LogMessage(LogLevel.Error, "REST", $"Request to {request.Url} triggered an {ex.GetType().Name}: {ex.Message}\n{ex.StackTrace}", DateTime.Now);
// if something went wrong and we couldn't get rate limits for the first request here, allow the next request to run
if (bucket != null && ratelimitTcs != null && bucket._limitTesting != 0)
{
this.FailInitialRateLimitTest(bucket, ratelimitTcs);
}
if (!request.TrySetFaulted(ex))
{
throw;
}
}
}
public async Task ExecuteRequestAsync(BaseRestRequest request)
{
if (request == null)
{
throw new ArgumentNullException(nameof(request));
}
await this.RequestSemaphore.WaitAsync().ConfigureAwait(false);
var bucket = request.RateLimitBucket;
var now = DateTimeOffset.UtcNow;
if (bucket.Remaining <= 0 && bucket.Maximum > 0 && now < bucket.Reset)
{
request.Discord.DebugLogger.LogMessage(LogLevel.Warning, "REST", $"Pre-emptive ratelimit triggered, waiting until {bucket.Reset.ToString("yyyy-MM-dd HH:mm:ss zzz")}", DateTime.Now);
_ = Task.Delay(bucket.Reset - now).ContinueWith(t => this.ExecuteRequestAsync(request));
this.RequestSemaphore.Release();
return;
}
var req = this.BuildRequest(request);
var response = new RestResponse();
try
{
var res = await HttpClient.SendAsync(req, HttpCompletionOption.ResponseContentRead).ConfigureAwait(false);
var bts = await res.Content.ReadAsByteArrayAsync().ConfigureAwait(false);
var txt = UTF8.GetString(bts, 0, bts.Length);
response.Headers = res.Headers.ToDictionary(xh => xh.Key, xh => string.Join("\n", xh.Value));
response.Response = txt;
response.ResponseCode = (int)res.StatusCode;
}
catch (HttpRequestException httpex)
{
request.Discord.DebugLogger.LogMessage(LogLevel.Error, "REST", $"Request to {request.Url} triggered an HttpException: {httpex.Message}", DateTime.Now);
request.SetFaulted(httpex);
this.RequestSemaphore.Release();
return;
}
this.UpdateBucket(request, response);
Exception ex = null;
switch (response.ResponseCode)
{
case 400:
case 405:
ex = new BadRequestException(request, response);
break;
case 401:
case 403:
ex = new UnauthorizedException(request, response);
break;
case 404:
ex = new NotFoundException(request, response);
break;
case 429:
ex = new RateLimitException(request, response);
// check the limit info, if more than one minute, fault, otherwise requeue
this.Handle429(response, out var wait, out var global);
if (wait != null)
{
wait = wait.ContinueWith(t => this.ExecuteRequestAsync(request));
if (global)
{
request.Discord.DebugLogger.LogMessage(LogLevel.Error, "REST", "Global ratelimit hit, cooling down", DateTime.Now);
await wait.ConfigureAwait(false);
}
else
{
request.Discord.DebugLogger.LogMessage(LogLevel.Error, "REST", $"Ratelimit hit, requeueing request to {request.Url}", DateTime.Now);
}
this.RequestSemaphore.Release();
return;
}
break;
}
this.RequestSemaphore.Release();
if (ex != null)
{
request.SetFaulted(ex);
}
else
{
request.SetCompleted(response);
}
}