github.com/calmw/ethereum@v0.1.1/metrics/writer.go (about)

     1  package metrics
     2  
     3  import (
     4  	"fmt"
     5  	"io"
     6  	"sort"
     7  	"time"
     8  )
     9  
    10  // Write sorts writes each metric in the given registry periodically to the
    11  // given io.Writer.
    12  func Write(r Registry, d time.Duration, w io.Writer) {
    13  	for range time.Tick(d) {
    14  		WriteOnce(r, w)
    15  	}
    16  }
    17  
    18  // WriteOnce sorts and writes metrics in the given registry to the given
    19  // io.Writer.
    20  func WriteOnce(r Registry, w io.Writer) {
    21  	var namedMetrics namedMetricSlice
    22  	r.Each(func(name string, i interface{}) {
    23  		namedMetrics = append(namedMetrics, namedMetric{name, i})
    24  	})
    25  
    26  	sort.Sort(namedMetrics)
    27  	for _, namedMetric := range namedMetrics {
    28  		switch metric := namedMetric.m.(type) {
    29  		case Counter:
    30  			fmt.Fprintf(w, "counter %s\n", namedMetric.name)
    31  			fmt.Fprintf(w, "  count:       %9d\n", metric.Count())
    32  		case CounterFloat64:
    33  			fmt.Fprintf(w, "counter %s\n", namedMetric.name)
    34  			fmt.Fprintf(w, "  count:       %f\n", metric.Count())
    35  		case Gauge:
    36  			fmt.Fprintf(w, "gauge %s\n", namedMetric.name)
    37  			fmt.Fprintf(w, "  value:       %9d\n", metric.Value())
    38  		case GaugeFloat64:
    39  			fmt.Fprintf(w, "gauge %s\n", namedMetric.name)
    40  			fmt.Fprintf(w, "  value:       %f\n", metric.Value())
    41  		case Healthcheck:
    42  			metric.Check()
    43  			fmt.Fprintf(w, "healthcheck %s\n", namedMetric.name)
    44  			fmt.Fprintf(w, "  error:       %v\n", metric.Error())
    45  		case Histogram:
    46  			h := metric.Snapshot()
    47  			ps := h.Percentiles([]float64{0.5, 0.75, 0.95, 0.99, 0.999})
    48  			fmt.Fprintf(w, "histogram %s\n", namedMetric.name)
    49  			fmt.Fprintf(w, "  count:       %9d\n", h.Count())
    50  			fmt.Fprintf(w, "  min:         %9d\n", h.Min())
    51  			fmt.Fprintf(w, "  max:         %9d\n", h.Max())
    52  			fmt.Fprintf(w, "  mean:        %12.2f\n", h.Mean())
    53  			fmt.Fprintf(w, "  stddev:      %12.2f\n", h.StdDev())
    54  			fmt.Fprintf(w, "  median:      %12.2f\n", ps[0])
    55  			fmt.Fprintf(w, "  75%%:         %12.2f\n", ps[1])
    56  			fmt.Fprintf(w, "  95%%:         %12.2f\n", ps[2])
    57  			fmt.Fprintf(w, "  99%%:         %12.2f\n", ps[3])
    58  			fmt.Fprintf(w, "  99.9%%:       %12.2f\n", ps[4])
    59  		case Meter:
    60  			m := metric.Snapshot()
    61  			fmt.Fprintf(w, "meter %s\n", namedMetric.name)
    62  			fmt.Fprintf(w, "  count:       %9d\n", m.Count())
    63  			fmt.Fprintf(w, "  1-min rate:  %12.2f\n", m.Rate1())
    64  			fmt.Fprintf(w, "  5-min rate:  %12.2f\n", m.Rate5())
    65  			fmt.Fprintf(w, "  15-min rate: %12.2f\n", m.Rate15())
    66  			fmt.Fprintf(w, "  mean rate:   %12.2f\n", m.RateMean())
    67  		case Timer:
    68  			t := metric.Snapshot()
    69  			ps := t.Percentiles([]float64{0.5, 0.75, 0.95, 0.99, 0.999})
    70  			fmt.Fprintf(w, "timer %s\n", namedMetric.name)
    71  			fmt.Fprintf(w, "  count:       %9d\n", t.Count())
    72  			fmt.Fprintf(w, "  min:         %9d\n", t.Min())
    73  			fmt.Fprintf(w, "  max:         %9d\n", t.Max())
    74  			fmt.Fprintf(w, "  mean:        %12.2f\n", t.Mean())
    75  			fmt.Fprintf(w, "  stddev:      %12.2f\n", t.StdDev())
    76  			fmt.Fprintf(w, "  median:      %12.2f\n", ps[0])
    77  			fmt.Fprintf(w, "  75%%:         %12.2f\n", ps[1])
    78  			fmt.Fprintf(w, "  95%%:         %12.2f\n", ps[2])
    79  			fmt.Fprintf(w, "  99%%:         %12.2f\n", ps[3])
    80  			fmt.Fprintf(w, "  99.9%%:       %12.2f\n", ps[4])
    81  			fmt.Fprintf(w, "  1-min rate:  %12.2f\n", t.Rate1())
    82  			fmt.Fprintf(w, "  5-min rate:  %12.2f\n", t.Rate5())
    83  			fmt.Fprintf(w, "  15-min rate: %12.2f\n", t.Rate15())
    84  			fmt.Fprintf(w, "  mean rate:   %12.2f\n", t.RateMean())
    85  		}
    86  	}
    87  }
    88  
    89  type namedMetric struct {
    90  	name string
    91  	m    interface{}
    92  }
    93  
    94  // namedMetricSlice is a slice of namedMetrics that implements sort.Interface.
    95  type namedMetricSlice []namedMetric
    96  
    97  func (nms namedMetricSlice) Len() int { return len(nms) }
    98  
    99  func (nms namedMetricSlice) Swap(i, j int) { nms[i], nms[j] = nms[j], nms[i] }
   100  
   101  func (nms namedMetricSlice) Less(i, j int) bool {
   102  	return nms[i].name < nms[j].name
   103  }