SecureDeleteWinForms.WipeTools.WipeSpeed.UpdateSpeed C# (CSharp) Method

        public long UpdateSpeed(long wiped)
        {
            values[position % MaxSpeedSteps] = wiped;
            times[position % MaxSpeedSteps] = Environment.TickCount;
            position++;

            // update ?
            if(Environment.TickCount - lastTick >= SpeedUpdateInterval) {
                int count = Math.Min(position, SpeedUpdateInterval);
                speed = 0;

                if(count < SpeedUpdateInterval) {
                    for(int i = 0; i < position; i++) {
                        if(i >= 1) {
                            long speedDiff = Math.Abs(values[i % MaxSpeedSteps] - values[(i - 1) % MaxSpeedSteps]);
                            int timeDiff = Math.Abs(times[i % MaxSpeedSteps] - times[(i - 1) % MaxSpeedSteps]);
                            speed += (1000 * speedDiff) / Math.Max(1, timeDiff);
                        }
                    }
                }
                else {
                    for(int i = 0; i < count; i++) {
                        speed += values[position % MaxSpeedSteps] - values[(position - 1) % MaxSpeedSteps];
                    }
                }

                speed /= Math.Max(1, count);
                lastTick = Environment.TickCount;
            }

            if(position == int.MaxValue) {
                position = MaxSpeedSteps;
            }

            return speed;
        }