package metrics import ( "fmt" "io" "strings" "time" "golang.org/x/exp/slices" ) // Write sorts writes each metric in the given registry periodically to the // given io.Writer. func Write(r Registry, d time.Duration, w io.Writer) { for range time.Tick(d) { WriteOnce(r, w) } } // WriteOnce sorts and writes metrics in the given registry to the given // io.Writer. func WriteOnce(r Registry, w io.Writer) { var namedMetrics []namedMetric r.Each(func(name string, i interface{}) { namedMetrics = append(namedMetrics, namedMetric{name, i}) }) slices.SortFunc(namedMetrics, namedMetric.cmp) for _, namedMetric := range namedMetrics { switch metric := namedMetric.m.(type) { case Counter: fmt.Fprintf(w, "counter %s\n", namedMetric.name) fmt.Fprintf(w, " count: %9d\n", metric.Count()) case CounterFloat64: fmt.Fprintf(w, "counter %s\n", namedMetric.name) fmt.Fprintf(w, " count: %f\n", metric.Count()) case Gauge: fmt.Fprintf(w, "gauge %s\n", namedMetric.name) fmt.Fprintf(w, " value: %9d\n", metric.Value()) case GaugeFloat64: fmt.Fprintf(w, "gauge %s\n", namedMetric.name) fmt.Fprintf(w, " value: %f\n", metric.Value()) case Healthcheck: metric.Check() fmt.Fprintf(w, "healthcheck %s\n", namedMetric.name) fmt.Fprintf(w, " error: %v\n", metric.Error()) case Histogram: h := metric.Snapshot() ps := h.Percentiles([]float64{0.5, 0.75, 0.95, 0.99, 0.999}) fmt.Fprintf(w, "histogram %s\n", namedMetric.name) fmt.Fprintf(w, " count: %9d\n", h.Count()) fmt.Fprintf(w, " min: %9d\n", h.Min()) fmt.Fprintf(w, " max: %9d\n", h.Max()) fmt.Fprintf(w, " mean: %12.2f\n", h.Mean()) fmt.Fprintf(w, " stddev: %12.2f\n", h.StdDev()) fmt.Fprintf(w, " median: %12.2f\n", ps[0]) fmt.Fprintf(w, " 75%%: %12.2f\n", ps[1]) fmt.Fprintf(w, " 95%%: %12.2f\n", ps[2]) fmt.Fprintf(w, " 99%%: %12.2f\n", ps[3]) fmt.Fprintf(w, " 99.9%%: %12.2f\n", ps[4]) case Meter: m := metric.Snapshot() fmt.Fprintf(w, "meter %s\n", namedMetric.name) fmt.Fprintf(w, " count: %9d\n", m.Count()) fmt.Fprintf(w, " 1-min rate: %12.2f\n", m.Rate1()) fmt.Fprintf(w, " 5-min rate: %12.2f\n", m.Rate5()) fmt.Fprintf(w, " 15-min rate: %12.2f\n", m.Rate15()) fmt.Fprintf(w, " mean rate: %12.2f\n", m.RateMean()) case Timer: t := metric.Snapshot() ps := t.Percentiles([]float64{0.5, 0.75, 0.95, 0.99, 0.999}) fmt.Fprintf(w, "timer %s\n", namedMetric.name) fmt.Fprintf(w, " count: %9d\n", t.Count()) fmt.Fprintf(w, " min: %9d\n", t.Min()) fmt.Fprintf(w, " max: %9d\n", t.Max()) fmt.Fprintf(w, " mean: %12.2f\n", t.Mean()) fmt.Fprintf(w, " stddev: %12.2f\n", t.StdDev()) fmt.Fprintf(w, " median: %12.2f\n", ps[0]) fmt.Fprintf(w, " 75%%: %12.2f\n", ps[1]) fmt.Fprintf(w, " 95%%: %12.2f\n", ps[2]) fmt.Fprintf(w, " 99%%: %12.2f\n", ps[3]) fmt.Fprintf(w, " 99.9%%: %12.2f\n", ps[4]) fmt.Fprintf(w, " 1-min rate: %12.2f\n", t.Rate1()) fmt.Fprintf(w, " 5-min rate: %12.2f\n", t.Rate5()) fmt.Fprintf(w, " 15-min rate: %12.2f\n", t.Rate15()) fmt.Fprintf(w, " mean rate: %12.2f\n", t.RateMean()) } } } type namedMetric struct { name string m interface{} } func (m namedMetric) cmp(other namedMetric) int { return strings.Compare(m.name, other.name) }