c# .net Leaky Bucket

클라이언트 요청 제한 Leaky Bucket

 

public class LeakyBucket
{
    private readonly int Capacity;
    private int Used;
    private readonly long LeakInterval;
    private long LastLeakTime;

    public LeakyBucket(int maxRequestPerSecond)
    {
        Capacity = maxRequestPerSecond;
        Used = 0;
        LeakInterval = (1000 / maxRequestPerSecond) * TimeSpan.TicksPerMillisecond;
        LastLeakTime = DateTime.UtcNow.Ticks;
    }

    public bool Allow()
    {
        // Leak
        long now = DateTime.UtcNow.Ticks;
        if (now > LastLeakTime)
        {
            long leaks = (now - LastLeakTime) / LeakInterval;
            if (leaks > 0L)
            {
                if (Used <= leaks)
                    Used = 0;
                else
                    Used -= (int) leaks;

                LastLeakTime = now;
            }
        }

        if (++Used >= Capacity)
            return false;

        return true;
    }
}