internal override void Combine(MutableAggregation other, double fraction)
{
if (!(other is MutableSum mutable))
{
throw new ArgumentException("MutableSum expected.");
}
this.Sum += fraction * mutable.Sum;
}
internal override void Combine(MutableAggregation other, double fraction)
{
if (!(other is MutableCount mutable))
{
throw new ArgumentException("MutableCount expected.");
}
var result = fraction * mutable.Count;
long rounded = (long)Math.Round(result);
this.Count += rounded;
}
// We don't compute fractional MutableDistribution, it's either whole or none.
internal override void Combine(MutableAggregation other, double fraction)
{
MutableDistribution mutableDistribution = other as MutableDistribution;
if (mutableDistribution == null)
{
throw new ArgumentException("MutableDistribution expected.");
}
if (Math.Abs(1.0 - fraction) > TOLERANCE)
{
return;
}
if (!(this.BucketBoundaries.Equals(mutableDistribution.BucketBoundaries)))
{
throw new ArgumentException("Bucket boundaries should match.");
}
// Algorithm for calculating the combination of sum of squared deviations:
// https://en.wikipedia.org/wiki/Algorithms_for_calculating_variance#Parallel_algorithm.
if (this.Count + mutableDistribution.Count > 0)
{
double delta = mutableDistribution.Mean - this.Mean;
this.SumOfSquaredDeviations =
this.SumOfSquaredDeviations
+ mutableDistribution.SumOfSquaredDeviations
+ Math.Pow(delta, 2)
* this.Count
* mutableDistribution.Count
/ (this.Count + mutableDistribution.Count);
}
this.Count += mutableDistribution.Count;
this.Sum += mutableDistribution.Sum;
this.Mean = this.Sum / this.Count;
if (mutableDistribution.Min < this.Min)
{
this.Min = mutableDistribution.Min;
}
if (mutableDistribution.Max > this.Max)
{
this.Max = mutableDistribution.Max;
}
long[] bucketCounts = mutableDistribution.BucketCounts;
for (int i = 0; i < bucketCounts.Length; i++)
{
this.BucketCounts[i] += bucketCounts[i];
}
}
internal override void Combine(MutableAggregation other, double fraction)
{
if (!(other is MutableLastValue mutable))
{
throw new ArgumentException("MutableLastValue expected.");
}
MutableLastValue otherValue = (MutableLastValue)other;
// Assume other is always newer than this, because we combined interval buckets in time order.
// If there's a newer value, overwrite current value.
this.LastValue = otherValue.Initialized ? otherValue.LastValue : this.LastValue;
}
internal static IAggregationData CreateAggregationData(MutableAggregation aggregation, IMeasure measure)
{
return(aggregation.Match <IAggregationData>(
(msum) =>
{
return measure.Match <IAggregationData>(
(mdouble) =>
{
return SumDataDouble.Create(msum.Sum);
},
(mlong) =>
{
return SumDataLong.Create((long)Math.Round(msum.Sum));
},
(invalid) =>
{
throw new ArgumentException();
});
},
CreateCountData,
CreateMeanData,
CreateDistributionData,
(mlval) =>
{
return measure.Match <IAggregationData>(
(mdouble) =>
{
return LastValueDataDouble.Create(mlval.LastValue);
},
(mlong) =>
{
if (Double.IsNaN(mlval.LastValue))
{
return LastValueDataLong.Create(0);
}
return LastValueDataLong.Create((long)Math.Round(mlval.LastValue));
},
(invalid) =>
{
throw new ArgumentException();
});
}
));
}
internal override void Combine(MutableAggregation other, double fraction)
{
MutableMean mutable = other as MutableMean;
if (mutable == null)
{
throw new ArgumentException("MutableMean expected.");
}
var result = fraction * mutable.Count;
long rounded = (long)Math.Round(result);
Count += rounded;
this.Sum += mutable.Sum * fraction;
if (mutable.Min < this.Min)
{
this.Min = mutable.Min;
}
if (mutable.Max > this.Max)
{
this.Max = mutable.Max;
}
}
internal abstract void Combine(MutableAggregation other, double fraction);
private static void Sum(MutableAggregation combined, IAggregationData data)
{
data.Match <object>(
(arg) =>
{
if (combined is MutableSum sum)
{
sum.Add(arg.Sum);
}
return(null);
},
(arg) =>
{
if (combined is MutableSum sum)
{
sum.Add(arg.Sum);
}
return(null);
},
(arg) =>
{
if (combined is MutableCount count)
{
count.Add(arg.Count);
}
return(null);
},
(arg) =>
{
if (combined is MutableMean mean)
{
mean.Count = mean.Count + arg.Count;
mean.Sum = mean.Sum + (arg.Count * arg.Mean);
if (arg.Min < mean.Min)
{
mean.Min = arg.Min;
}
if (arg.Max > mean.Max)
{
mean.Max = arg.Max;
}
}
return(null);
},
(arg) =>
{
if (combined is MutableDistribution dist)
{
// Algorithm for calculating the combination of sum of squared deviations:
// https://en.wikipedia.org/wiki/Algorithms_for_calculating_variance#Parallel_algorithm.
if (dist.Count + arg.Count > 0)
{
double delta = arg.Mean - dist.Mean;
dist.SumOfSquaredDeviations =
dist.SumOfSquaredDeviations
+ arg.SumOfSquaredDeviations
+ (Math.Pow(delta, 2)
* dist.Count
* arg.Count
/ (dist.Count + arg.Count));
}
dist.Count += arg.Count;
dist.Sum += arg.Mean * arg.Count;
dist.Mean = dist.Sum / dist.Count;
if (arg.Min < dist.Min)
{
dist.Min = arg.Min;
}
if (arg.Max > dist.Max)
{
dist.Max = arg.Max;
}
IList <long> bucketCounts = arg.BucketCounts;
for (int i = 0; i < bucketCounts.Count; i++)
{
dist.BucketCounts[i] += bucketCounts[i];
}
}
return(null);
},
(arg) =>
{
if (combined is MutableLastValue lastValue)
{
lastValue.Initialized = true;
if (double.IsNaN(lastValue.LastValue))
{
lastValue.LastValue = arg.LastValue;
}
else
{
lastValue.LastValue += arg.LastValue;
}
}
return(null);
},
(arg) =>
{
if (combined is MutableLastValue lastValue)
{
lastValue.Initialized = true;
if (double.IsNaN(lastValue.LastValue))
{
lastValue.LastValue = arg.LastValue;
}
else
{
lastValue.LastValue += arg.LastValue;
}
}
return(null);
},
(arg) =>
{
throw new ArgumentException();
});
}
