protected override Task <HttpResponseMessage> SendAsync(HttpRequestMessage request, CancellationToken cancellationToken)
{
var identifier = GetUserIdentifier(request);
if (string.IsNullOrEmpty(identifier))
{
return(CreateResponse(request, HttpStatusCode.Forbidden, "Could not identify client."));
}
var maxRequests = _maxRequestsForUserIdentifier(identifier);
ThrottleEntry entry = null;
if (_store.TryGetValue(identifier, out entry))
{
if (entry.PeriodStart + _period < DateTime.UtcNow)
{
_store.Rollover(identifier);
}
}
_store.IncrementRequests(identifier);
if (!_store.TryGetValue(identifier, out entry))
{
return(CreateResponse(request, HttpStatusCode.Forbidden, "Could not identify client."));
}
Task <HttpResponseMessage> response = null;
if (entry.Requests > maxRequests)
{
response = CreateResponse(request, HttpStatusCode.ServiceUnavailable, _message);
}
else
{
response = base.SendAsync(request, cancellationToken);
}
return(response.ContinueWith(task =>
{
var remaining = maxRequests - entry.Requests;
if (remaining < 0)
{
remaining = 0;
}
var httpResponse = task.Result;
httpResponse.Headers.Add("RateLimit-Limit", maxRequests.ToString());
httpResponse.Headers.Add("RateLimit-Remaining", remaining.ToString());
return httpResponse;
}));
}
public bool TryGetValue(string key, out ThrottleEntry entry)
{
return(_throttleStore.TryGetValue(key, out entry));
}
public bool TryGetValue(string key, out ThrottleEntry entry)
{
return _throttleStore.TryGetValue(key, out entry);
}