1
2
3
4
5
6
7
8
9
10
11
12
13
14
15
16
17
18
19
20
21
22
23
24
25
26
27
28
29
30
31
32
33
34
35
36
37
38
39
40
41
42
43
44
45
46
47
48
49
50
51
52
53
54
55
56
57
58
59
60
61
62
63
64
65
66
67
68
69
70
71
72
73
74
75
76
77
78
79
80
81
82
83
|
/*
Implements some additional prometheus metrics that we need for privacy preserving
counts of users and proxies
*/
package main
import (
"sync/atomic"
"github.com/prometheus/client_golang/prometheus"
dto "github.com/prometheus/client_model/go"
"google.golang.org/protobuf/proto"
)
// New Prometheus counter type that produces rounded counts of metrics
// for privacy preserving reasons
type RoundedCounter interface {
prometheus.Metric
Inc()
}
type roundedCounter struct {
total uint64 //reflects the true count
value uint64 //reflects the rounded count
desc *prometheus.Desc
labelPairs []*dto.LabelPair
}
// Implements the RoundedCounter interface
func (c *roundedCounter) Inc() {
atomic.AddUint64(&c.total, 1)
if c.total > c.value {
atomic.AddUint64(&c.value, 8)
}
}
// Implements the prometheus.Metric interface
func (c *roundedCounter) Desc() *prometheus.Desc {
return c.desc
}
// Implements the prometheus.Metric interface
func (c *roundedCounter) Write(m *dto.Metric) error {
m.Label = c.labelPairs
m.Counter = &dto.Counter{Value: proto.Float64(float64(c.value))}
return nil
}
// New prometheus vector type that will track RoundedCounter metrics
// accross multiple labels
type RoundedCounterVec struct {
*prometheus.MetricVec
}
func NewRoundedCounterVec(opts prometheus.CounterOpts, labelNames []string) *RoundedCounterVec {
desc := prometheus.NewDesc(
prometheus.BuildFQName(opts.Namespace, opts.Subsystem, opts.Name),
opts.Help,
labelNames,
opts.ConstLabels,
)
return &RoundedCounterVec{
MetricVec: prometheus.NewMetricVec(desc, func(lvs ...string) prometheus.Metric {
if len(lvs) != len(labelNames) {
panic("inconsistent cardinality")
}
return &roundedCounter{desc: desc, labelPairs: prometheus.MakeLabelPairs(desc, lvs)}
}),
}
}
// Helper function to return the underlying RoundedCounter metric from MetricVec
func (v *RoundedCounterVec) With(labels prometheus.Labels) RoundedCounter {
metric, err := v.GetMetricWith(labels)
if err != nil {
panic(err)
}
return metric.(RoundedCounter)
}
|
