log.go

Documentation: github.com/rcrowley/go-metrics

     1  package metrics
     2  
     3  import (
     4  	"time"
     5  )
     6  
     7  type Logger interface {
     8  	Printf(format string, v ...interface{})
     9  }
    10  
    11  // Log outputs each metric in the given registry periodically using the given logger.
    12  func Log(r Registry, freq time.Duration, l Logger) {
    13  	LogScaled(r, freq, time.Nanosecond, l)
    14  }
    15  
    16  // LogOnCue outputs each metric in the given registry on demand through the channel
    17  // using the given logger
    18  func LogOnCue(r Registry, ch chan interface{}, l Logger) {
    19  	LogScaledOnCue(r, ch, time.Nanosecond, l)
    20  }
    21  
    22  // LogScaled outputs each metric in the given registry periodically using the given
    23  // logger. Print timings in `scale` units (eg time.Millisecond) rather than nanos.
    24  func LogScaled(r Registry, freq time.Duration, scale time.Duration, l Logger) {
    25  	ch := make(chan interface{})
    26  	go func(channel chan interface{}) {
    27  		for _ = range time.Tick(freq) {
    28  			channel <- struct{}{}
    29  		}
    30  	}(ch)
    31  	LogScaledOnCue(r, ch, scale, l)
    32  }
    33  
    34  // LogScaledOnCue outputs each metric in the given registry on demand through the channel
    35  // using the given logger. Print timings in `scale` units (eg time.Millisecond) rather
    36  // than nanos.
    37  func LogScaledOnCue(r Registry, ch chan interface{}, scale time.Duration, l Logger) {
    38  	du := float64(scale)
    39  	duSuffix := scale.String()[1:]
    40  
    41  	for _ = range ch {
    42  		r.Each(func(name string, i interface{}) {
    43  			switch metric := i.(type) {
    44  			case Counter:
    45  				l.Printf("counter %s\n", name)
    46  				l.Printf("  count:       %9d\n", metric.Count())
    47  			case Gauge:
    48  				l.Printf("gauge %s\n", name)
    49  				l.Printf("  value:       %9d\n", metric.Value())
    50  			case GaugeFloat64:
    51  				l.Printf("gauge %s\n", name)
    52  				l.Printf("  value:       %f\n", metric.Value())
    53  			case Healthcheck:
    54  				metric.Check()
    55  				l.Printf("healthcheck %s\n", name)
    56  				l.Printf("  error:       %v\n", metric.Error())
    57  			case Histogram:
    58  				h := metric.Snapshot()
    59  				ps := h.Percentiles([]float64{0.5, 0.75, 0.95, 0.99, 0.999})
    60  				l.Printf("histogram %s\n", name)
    61  				l.Printf("  count:       %9d\n", h.Count())
    62  				l.Printf("  min:         %9d\n", h.Min())
    63  				l.Printf("  max:         %9d\n", h.Max())
    64  				l.Printf("  mean:        %12.2f\n", h.Mean())
    65  				l.Printf("  stddev:      %12.2f\n", h.StdDev())
    66  				l.Printf("  median:      %12.2f\n", ps[0])
    67  				l.Printf("  75%%:         %12.2f\n", ps[1])
    68  				l.Printf("  95%%:         %12.2f\n", ps[2])
    69  				l.Printf("  99%%:         %12.2f\n", ps[3])
    70  				l.Printf("  99.9%%:       %12.2f\n", ps[4])
    71  			case Meter:
    72  				m := metric.Snapshot()
    73  				l.Printf("meter %s\n", name)
    74  				l.Printf("  count:       %9d\n", m.Count())
    75  				l.Printf("  1-min rate:  %12.2f\n", m.Rate1())
    76  				l.Printf("  5-min rate:  %12.2f\n", m.Rate5())
    77  				l.Printf("  15-min rate: %12.2f\n", m.Rate15())
    78  				l.Printf("  mean rate:   %12.2f\n", m.RateMean())
    79  			case Timer:
    80  				t := metric.Snapshot()
    81  				ps := t.Percentiles([]float64{0.5, 0.75, 0.95, 0.99, 0.999})
    82  				l.Printf("timer %s\n", name)
    83  				l.Printf("  count:       %9d\n", t.Count())
    84  				l.Printf("  min:         %12.2f%s\n", float64(t.Min())/du, duSuffix)
    85  				l.Printf("  max:         %12.2f%s\n", float64(t.Max())/du, duSuffix)
    86  				l.Printf("  mean:        %12.2f%s\n", t.Mean()/du, duSuffix)
    87  				l.Printf("  stddev:      %12.2f%s\n", t.StdDev()/du, duSuffix)
    88  				l.Printf("  median:      %12.2f%s\n", ps[0]/du, duSuffix)
    89  				l.Printf("  75%%:         %12.2f%s\n", ps[1]/du, duSuffix)
    90  				l.Printf("  95%%:         %12.2f%s\n", ps[2]/du, duSuffix)
    91  				l.Printf("  99%%:         %12.2f%s\n", ps[3]/du, duSuffix)
    92  				l.Printf("  99.9%%:       %12.2f%s\n", ps[4]/du, duSuffix)
    93  				l.Printf("  1-min rate:  %12.2f\n", t.Rate1())
    94  				l.Printf("  5-min rate:  %12.2f\n", t.Rate5())
    95  				l.Printf("  15-min rate: %12.2f\n", t.Rate15())
    96  				l.Printf("  mean rate:   %12.2f\n", t.RateMean())
    97  			}
    98  		})
    99  	}
   100  }
   101
View as plain text