/**
* Compute the alpha decay factor such that the weight of an entry with age 'targetAgeInSeconds' is targetWeight'
*/
public static double ComputeAlpha(double targetWeight, long targetAgeInSeconds)
{
ParameterCheck.Check(targetAgeInSeconds > 0, "targetAgeInSeconds must be > 0");
ParameterCheck.Check(targetWeight > 0 && targetWeight < 1, "targetWeight must be in range (0, 1)");
return(-Math.Log(targetWeight) / targetAgeInSeconds);
}
public void Merge(DecayCounter decayCounter)
{
if (decayCounter == null)
{
throw new ArgumentNullException("decayCounter");
}
ParameterCheck.Check(decayCounter.Alpha == this.Alpha, $"Expected decayCounter to have alpha {this.Alpha}, but was {decayCounter.Alpha}.");
lock (SyncRoot)
{
// if the landmark this counter is behind the other counter
if (this.LandmarkInSeconds < decayCounter.LandmarkInSeconds)
{
// rescale this counter to the other counter, and add
this.RescaleToNewLandmark(decayCounter.LandmarkInSeconds);
this.Count += decayCounter.Count;
}
else
{
// rescale the other counter and add
double OtherRescaledCount = decayCounter.Count / this.Weight(this.LandmarkInSeconds, decayCounter.LandmarkInSeconds);
this.Count += OtherRescaledCount;
}
}
}
public long ToBytes()
{
double Bytes = this.GetValue(DataSizeUnit.BYTE);
ParameterCheck.Check(Bytes <= Int64.MaxValue, "Size in bytes is too large to be represented in bytes as a long.");
return((long)Bytes);
}
public static Slice Allocate(int capacity)
{
if (capacity == 0)
{
return(EMPTY_SLICE);
}
ParameterCheck.Check(capacity <= MAX_ARRAY_SIZE, $"Cannot allocate slice largert than {MAX_ARRAY_SIZE} bytes.");
return(new Slice(new byte[capacity]));
}