/// <summary>
/// Insert or update
/// </summary>
public void Save(string id, ThrottleCounter throttleCounter, TimeSpan expirationTime)
{
if (HttpContext.Current.Cache[id] != null)
{
HttpContext.Current.Cache[id] = throttleCounter;
}
else
{
HttpContext.Current.Cache.Add(
id,
throttleCounter,
null,
Cache.NoAbsoluteExpiration,
expirationTime,
CacheItemPriority.Low,
null);
}
}
private ThrottleCounter ProcessRequest(RequestIdentity requestIdentity, TimeSpan timeSpan, RateLimitPeriod period, out string id)
{
var throttleCounter = new ThrottleCounter()
{
Timestamp = System.DateTime.UtcNow,
TotalRequests = 1
};
id = ComputeThrottleKey(requestIdentity, period);
//serial reads and writes
lock (_processLocker)
{
var entry = Repository.FirstOrDefault(id);
if (entry.HasValue)
{
//entry has not expired
if (entry.Value.Timestamp + timeSpan >= System.DateTime.UtcNow)
{
//increment request count
var totalRequests = entry.Value.TotalRequests + 1;
//deep copy
throttleCounter = new ThrottleCounter
{
Timestamp = entry.Value.Timestamp,
TotalRequests = totalRequests
};
}
}
//stores: id (string) - timestamp (datetime) - total (long)
Repository.Save(id, throttleCounter, timeSpan);
}
return throttleCounter;
}
private ThrottleLogEntry ComputeLogEntry(string requestId, RequestIdentity identity, ThrottleCounter throttleCounter, string rateLimitPeriod, long rateLimit, HttpRequestBase request)
{
return new ThrottleLogEntry
{
ClientIp = identity.ClientIp,
ClientKey = identity.ClientKey,
Endpoint = identity.Endpoint,
LogDate = System.DateTime.UtcNow,
RateLimit = rateLimit,
RateLimitPeriod = rateLimitPeriod,
RequestId = requestId,
StartPeriod = throttleCounter.Timestamp,
TotalRequests = throttleCounter.TotalRequests,
Request = request
};
}
