private bool ApplyThrottling(HttpActionContext filterContext, out EnableThrottlingAttribute attr)
{
var applyThrottling = false;
attr = null;
if (filterContext.ActionDescriptor.ControllerDescriptor.GetCustomAttributes <EnableThrottlingAttribute>(true).Count > 0)
{
attr = filterContext.ActionDescriptor.ControllerDescriptor.GetCustomAttributes <EnableThrottlingAttribute>(true).First();
applyThrottling = true;
}
if (filterContext.ActionDescriptor.GetCustomAttributes <EnableThrottlingAttribute>(true).Count > 0)
{
attr = filterContext.ActionDescriptor.GetCustomAttributes <EnableThrottlingAttribute>(true).First();
applyThrottling = true;
}
// explicit disabled
if (filterContext.ActionDescriptor.GetCustomAttributes <DisableThrottingAttribute>(true).Count > 0)
{
applyThrottling = false;
}
return(applyThrottling);
}
public override void OnActionExecuting(HttpActionContext actionContext)
{
EnableThrottlingAttribute attrPolicy = null;
var applyThrottling = ApplyThrottling(actionContext, out attrPolicy);
// get policy from repo
if (policyRepository != null)
{
policy = policyRepository.FirstOrDefault(ThrottleManager.GetPolicyKey());
}
if (Policy != null && applyThrottling)
{
core.Repository = Repository;
core.Policy = Policy;
var identity = SetIndentity(actionContext.Request);
if (!core.IsWhitelisted(identity))
{
TimeSpan timeSpan = TimeSpan.FromSeconds(1);
// get default rates
var defRates = core.RatesWithDefaults(Policy.Rates.ToList());
if (Policy.StackBlockedRequests)
{
// all requests including the rejected ones will stack in this order: week, day, hour, min, sec
// if a client hits the hour limit then the minutes and seconds counters will expire and will eventually get erased from cache
defRates.Reverse();
}
// apply policy
foreach (var rate in defRates)
{
var rateLimitPeriod = rate.Key;
var rateLimit = rate.Value;
timeSpan = core.GetTimeSpanFromPeriod(rateLimitPeriod);
// apply EnableThrottlingAttribute policy
var attrLimit = attrPolicy.GetLimit(rateLimitPeriod);
if (attrLimit > 0)
{
rateLimit = attrLimit;
}
// apply global rules
core.ApplyRules(identity, timeSpan, rateLimitPeriod, ref rateLimit);
if (rateLimit > 0)
{
// increment counter
string requestId;
var throttleCounter = core.ProcessRequest(identity, timeSpan, rateLimitPeriod, out requestId);
// check if key expired
if (throttleCounter.Timestamp + timeSpan < DateTime.UtcNow)
{
continue;
}
// check if limit is reached
if (throttleCounter.TotalRequests > rateLimit)
{
// log blocked request
if (Logger != null)
{
Logger.Log(core.ComputeLogEntry(requestId, identity, throttleCounter, rateLimitPeriod.ToString(), rateLimit, actionContext.Request));
}
var message = !string.IsNullOrEmpty(this.QuotaExceededMessage)
? this.QuotaExceededMessage
: "API calls quota exceeded! maximum admitted {0} per {1}.";
var content = this.QuotaExceededContent != null
? this.QuotaExceededContent(rateLimit, rateLimitPeriod)
: string.Format(message, rateLimit, rateLimitPeriod);
// add status code and retry after x seconds to response
actionContext.Response = QuotaExceededResponse(
actionContext.Request,
string.Format(message, rateLimit, rateLimitPeriod),
QuotaExceededResponseCode,
core.RetryAfterFrom(throttleCounter.Timestamp, rateLimitPeriod));
}
}
}
}
}
base.OnActionExecuting(actionContext);
}
private bool ApplyThrottling(HttpActionContext filterContext, out EnableThrottlingAttribute attr)
{
var applyThrottling = false;
attr = null;
if (filterContext.ActionDescriptor.ControllerDescriptor.GetCustomAttributes<EnableThrottlingAttribute>(true).Any())
{
attr = filterContext.ActionDescriptor.ControllerDescriptor.GetCustomAttributes<EnableThrottlingAttribute>(true).First();
applyThrottling = true;
}
if (filterContext.ActionDescriptor.GetCustomAttributes<EnableThrottlingAttribute>(true).Any())
{
attr = filterContext.ActionDescriptor.GetCustomAttributes<EnableThrottlingAttribute>(true).First();
applyThrottling = true;
}
// explicit disabled
if (filterContext.ActionDescriptor.GetCustomAttributes<DisableThrottingAttribute>(true).Any())
{
applyThrottling = false;
}
return applyThrottling;
}
