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d2f2902b-79c4-43cd-8c09-341e33fc6017/v0.11.0

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timer.go @d2f2902b-79c4-43cd-8c09-341e33fc6017/v0.11.0raw · history · blame

package metrics

import "time"

// Timer acts as a stopwatch, sending observations to a wrapped histogram.
// It's a bit of helpful syntax sugar for h.Observe(time.Since(x)).
type Timer struct {
	h Histogram
	t time.Time
	u time.Duration
}

// NewTimer wraps the given histogram and records the current time.
func NewTimer(h Histogram) *Timer {
	return &Timer{
		h: h,
		t: time.Now(),
		u: time.Second,
	}
}

// ObserveDuration captures the number of seconds since the timer was
// constructed, and forwards that observation to the histogram.
func (t *Timer) ObserveDuration() {
	d := float64(time.Since(t.t).Nanoseconds()) / float64(t.u)
	if d < 0 {
		d = 0
	}
	t.h.Observe(d)
}

// Unit sets the unit of the float64 emitted by the timer.
// By default, the timer emits seconds.
func (t *Timer) Unit(u time.Duration) {
	t.u = u
}