50 lines
1.0 KiB
Go
50 lines
1.0 KiB
Go
package metrics
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import (
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"fmt"
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"io"
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)
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// NewGauge registers and returns gauge with the given name, which calls f
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// to obtain gauge value.
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//
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// name must be valid Prometheus-compatible metric with possible labels.
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// For instance,
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//
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// * foo
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// * foo{bar="baz"}
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// * foo{bar="baz",aaa="b"}
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//
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// f must be safe for concurrent calls.
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//
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// The returned gauge is safe to use from concurrent goroutines.
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func NewGauge(name string, f func() float64) *Gauge {
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g := &Gauge{
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f: f,
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}
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registerMetric(name, g)
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return g
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}
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// Gauge is a float64 gauge.
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//
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// See also Counter, which could be used as a gauge with Set and Dec calls.
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type Gauge struct {
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f func() float64
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}
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// Get returns the current value for g.
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func (g *Gauge) Get() float64 {
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return g.f()
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}
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func (g *Gauge) marshalTo(prefix string, w io.Writer) {
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v := g.f()
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if float64(int64(v)) == v {
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// Marshal integer values without scientific notations
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fmt.Fprintf(w, "%s %d\n", prefix, int64(v))
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} else {
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fmt.Fprintf(w, "%s %g\n", prefix, v)
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}
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}
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