github.com/sj-piano/go-ethereum@v1.9.7/metrics/prometheus/collector.go (about)

     1  // Copyright 2019 The go-ethereum Authors
     2  // This file is part of the go-ethereum library.
     3  //
     4  // The go-ethereum library is free software: you can redistribute it and/or modify
     5  // it under the terms of the GNU Lesser General Public License as published by
     6  // the Free Software Foundation, either version 3 of the License, or
     7  // (at your option) any later version.
     8  //
     9  // The go-ethereum library is distributed in the hope that it will be useful,
    10  // but WITHOUT ANY WARRANTY; without even the implied warranty of
    11  // MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE. See the
    12  // GNU Lesser General Public License for more details.
    13  //
    14  // You should have received a copy of the GNU Lesser General Public License
    15  // along with the go-ethereum library. If not, see <http://www.gnu.org/licenses/>.
    16  
    17  package prometheus
    18  
    19  import (
    20  	"bytes"
    21  	"fmt"
    22  	"strconv"
    23  	"strings"
    24  
    25  	"github.com/ethereum/go-ethereum/metrics"
    26  )
    27  
    28  var (
    29  	typeGaugeTpl           = "# TYPE %s gauge\n"
    30  	typeCounterTpl         = "# TYPE %s counter\n"
    31  	typeSummaryTpl         = "# TYPE %s summary\n"
    32  	keyValueTpl            = "%s %v\n\n"
    33  	keyQuantileTagValueTpl = "%s {quantile=\"%s\"} %v\n\n"
    34  )
    35  
    36  // collector is a collection of byte buffers that aggregate Prometheus reports
    37  // for different metric types.
    38  type collector struct {
    39  	buff *bytes.Buffer
    40  }
    41  
    42  // newCollector createa a new Prometheus metric aggregator.
    43  func newCollector() *collector {
    44  	return &collector{
    45  		buff: &bytes.Buffer{},
    46  	}
    47  }
    48  
    49  func (c *collector) addCounter(name string, m metrics.Counter) {
    50  	c.writeGaugeCounter(name, m.Count())
    51  }
    52  
    53  func (c *collector) addGauge(name string, m metrics.Gauge) {
    54  	c.writeGaugeCounter(name, m.Value())
    55  }
    56  
    57  func (c *collector) addGaugeFloat64(name string, m metrics.GaugeFloat64) {
    58  	c.writeGaugeCounter(name, m.Value())
    59  }
    60  
    61  func (c *collector) addHistogram(name string, m metrics.Histogram) {
    62  	pv := []float64{0.5, 0.75, 0.95, 0.99, 0.999, 0.9999}
    63  	ps := m.Percentiles(pv)
    64  	c.writeSummaryCounter(name, m.Count())
    65  	for i := range pv {
    66  		c.writeSummaryPercentile(name, strconv.FormatFloat(pv[i], 'f', -1, 64), ps[i])
    67  	}
    68  }
    69  
    70  func (c *collector) addMeter(name string, m metrics.Meter) {
    71  	c.writeGaugeCounter(name, m.Count())
    72  }
    73  
    74  func (c *collector) addTimer(name string, m metrics.Timer) {
    75  	pv := []float64{0.5, 0.75, 0.95, 0.99, 0.999, 0.9999}
    76  	ps := m.Percentiles(pv)
    77  	c.writeSummaryCounter(name, m.Count())
    78  	for i := range pv {
    79  		c.writeSummaryPercentile(name, strconv.FormatFloat(pv[i], 'f', -1, 64), ps[i])
    80  	}
    81  }
    82  
    83  func (c *collector) addResettingTimer(name string, m metrics.ResettingTimer) {
    84  	if len(m.Values()) <= 0 {
    85  		return
    86  	}
    87  	ps := m.Percentiles([]float64{50, 95, 99})
    88  	val := m.Values()
    89  	c.writeSummaryCounter(name, len(val))
    90  	c.writeSummaryPercentile(name, "0.50", ps[0])
    91  	c.writeSummaryPercentile(name, "0.95", ps[1])
    92  	c.writeSummaryPercentile(name, "0.99", ps[2])
    93  }
    94  
    95  func (c *collector) writeGaugeCounter(name string, value interface{}) {
    96  	name = mutateKey(name)
    97  	c.buff.WriteString(fmt.Sprintf(typeGaugeTpl, name))
    98  	c.buff.WriteString(fmt.Sprintf(keyValueTpl, name, value))
    99  }
   100  
   101  func (c *collector) writeSummaryCounter(name string, value interface{}) {
   102  	name = mutateKey(name + "_count")
   103  	c.buff.WriteString(fmt.Sprintf(typeCounterTpl, name))
   104  	c.buff.WriteString(fmt.Sprintf(keyValueTpl, name, value))
   105  }
   106  
   107  func (c *collector) writeSummaryPercentile(name, p string, value interface{}) {
   108  	name = mutateKey(name)
   109  	c.buff.WriteString(fmt.Sprintf(typeSummaryTpl, name))
   110  	c.buff.WriteString(fmt.Sprintf(keyQuantileTagValueTpl, name, p, value))
   111  }
   112  
   113  func mutateKey(key string) string {
   114  	return strings.Replace(key, "/", "_", -1)
   115  }