traefik/vendor/github.com/codahale/hdrhistogram/window.go

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2017-02-07 21:33:23 +00:00
package hdrhistogram
// A WindowedHistogram combines histograms to provide windowed statistics.
type WindowedHistogram struct {
idx int
h []Histogram
m *Histogram
Current *Histogram
}
// NewWindowed creates a new WindowedHistogram with N underlying histograms with
// the given parameters.
func NewWindowed(n int, minValue, maxValue int64, sigfigs int) *WindowedHistogram {
w := WindowedHistogram{
idx: -1,
h: make([]Histogram, n),
m: New(minValue, maxValue, sigfigs),
}
for i := range w.h {
w.h[i] = *New(minValue, maxValue, sigfigs)
}
w.Rotate()
return &w
}
// Merge returns a histogram which includes the recorded values from all the
// sections of the window.
func (w *WindowedHistogram) Merge() *Histogram {
w.m.Reset()
for _, h := range w.h {
w.m.Merge(&h)
}
return w.m
}
// Rotate resets the oldest histogram and rotates it to be used as the current
// histogram.
func (w *WindowedHistogram) Rotate() {
w.idx++
w.Current = &w.h[w.idx%len(w.h)]
w.Current.Reset()
}