1 files changed, 66 insertions, 0 deletions
diff --git a/vendor/github.com/vbauerster/mpb/decor/moving-average.go b/vendor/github.com/vbauerster/mpb/decor/moving-average.go
new file mode 100644
index 000000000..f9596a27f
--- /dev/null
+++ b/vendor/github.com/vbauerster/mpb/decor/moving-average.go
@@ -0,0 +1,66 @@
+package decor
+
+import (
+	"sort"
+
+	"github.com/VividCortex/ewma"
+)
+
+// MovingAverage is the interface that computes a moving average over a time-
+// series stream of numbers. The average may be over a window or exponentially
+// decaying.
+type MovingAverage interface {
+	Add(float64)
+	Value() float64
+	Set(float64)
+}
+
+type medianWindow [3]float64
+
+func (s *medianWindow) Len() int           { return len(s) }
+func (s *medianWindow) Swap(i, j int)      { s[i], s[j] = s[j], s[i] }
+func (s *medianWindow) Less(i, j int) bool { return s[i] < s[j] }
+
+func (s *medianWindow) Add(value float64) {
+	s[0], s[1] = s[1], s[2]
+	s[2] = value
+}
+
+func (s *medianWindow) Value() float64 {
+	tmp := *s
+	sort.Sort(&tmp)
+	return tmp[1]
+}
+
+func (s *medianWindow) Set(value float64) {
+	for i := 0; i < len(s); i++ {
+		s[i] = value
+	}
+}
+
+// NewMedian is fixed last 3 samples median MovingAverage.
+func NewMedian() MovingAverage {
+	return new(medianWindow)
+}
+
+type medianEwma struct {
+	count  uint
+	median MovingAverage
+	MovingAverage
+}
+
+func (s *medianEwma) Add(v float64) {
+	s.median.Add(v)
+	if s.count >= 2 {
+		s.MovingAverage.Add(s.median.Value())
+	}
+	s.count++
+}
+
+// NewMedianEwma is ewma based MovingAverage, which gets its values from median MovingAverage.
+func NewMedianEwma(age ...float64) MovingAverage {
+	return &medianEwma{
+		MovingAverage: ewma.NewMovingAverage(age...),
+		median:        NewMedian(),
+	}
+}