mirror of
https://github.com/tailscale/tailscale.git
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50 lines
1.2 KiB
Go
50 lines
1.2 KiB
Go
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// Copyright (c) Tailscale Inc & AUTHORS
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// SPDX-License-Identifier: BSD-3-Clause
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package prober
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import (
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"slices"
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"sync"
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)
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// histogram serves as an adapter to the Prometheus histogram datatype.
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// The prober framework passes labels at custom metric collection time that
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// it expects to be coupled with the returned metrics. See ProbeClass.Metrics
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// and its call sites. Native prometheus histograms cannot be collected while
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// injecting more labels. Instead we use this type and pass observations +
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// collection labels to prometheus.MustNewConstHistogram() at prometheus
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// metric collection time.
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type histogram struct {
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count uint64
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sum float64
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buckets []float64
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bucketedCounts map[float64]uint64
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mx sync.Mutex
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}
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// newHistogram constructs a histogram that buckets data based on the given
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// slice of upper bounds.
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func newHistogram(buckets []float64) *histogram {
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slices.Sort(buckets)
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return &histogram{
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buckets: buckets,
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bucketedCounts: make(map[float64]uint64, len(buckets)),
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}
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}
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func (h *histogram) add(v float64) {
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h.mx.Lock()
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defer h.mx.Unlock()
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h.count++
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h.sum += v
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for _, b := range h.buckets {
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if v > b {
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continue
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}
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h.bucketedCounts[b] += 1
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}
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}
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