.config/coc/extensions/coc-go-data/tools/pkg/mod/golang.org/x/tools@v0.0.0-20201028153306-37f0764111ff/internal/event/export/prometheus/prometheus.go

   1 // Copyright 2019 The Go Authors. All rights reserved.
   2 // Use of this source code is governed by a BSD-style
   3 // license that can be found in the LICENSE file.
   4
   5 package prometheus
   6
   7 import (
   8         "bytes"
   9         "context"
  10         "fmt"
  11         "net/http"
  12         "sort"
  13         "sync"
  14
  15         "golang.org/x/tools/internal/event"
  16         "golang.org/x/tools/internal/event/core"
  17         "golang.org/x/tools/internal/event/export/metric"
  18         "golang.org/x/tools/internal/event/label"
  19 )
  20
  21 func New() *Exporter {
  22         return &Exporter{}
  23 }
  24
  25 type Exporter struct {
  26         mu      sync.Mutex
  27         metrics []metric.Data
  28 }
  29
  30 func (e *Exporter) ProcessEvent(ctx context.Context, ev core.Event, ln label.Map) context.Context {
  31         if !event.IsMetric(ev) {
  32                 return ctx
  33         }
  34         e.mu.Lock()
  35         defer e.mu.Unlock()
  36         metrics := metric.Entries.Get(ln).([]metric.Data)
  37         for _, data := range metrics {
  38                 name := data.Handle()
  39                 // We keep the metrics in name sorted order so the page is stable and easy
  40                 // to read. We do this with an insertion sort rather than sorting the list
  41                 // each time
  42                 index := sort.Search(len(e.metrics), func(i int) bool {
  43                         return e.metrics[i].Handle() >= name
  44                 })
  45                 if index >= len(e.metrics) || e.metrics[index].Handle() != name {
  46                         // we have a new metric, so we need to make a space for it
  47                         old := e.metrics
  48                         e.metrics = make([]metric.Data, len(old)+1)
  49                         copy(e.metrics, old[:index])
  50                         copy(e.metrics[index+1:], old[index:])
  51                 }
  52                 e.metrics[index] = data
  53         }
  54         return ctx
  55 }
  56
  57 func (e *Exporter) header(w http.ResponseWriter, name, description string, isGauge, isHistogram bool) {
  58         kind := "counter"
  59         if isGauge {
  60                 kind = "gauge"
  61         }
  62         if isHistogram {
  63                 kind = "histogram"
  64         }
  65         fmt.Fprintf(w, "# HELP %s %s\n", name, description)
  66         fmt.Fprintf(w, "# TYPE %s %s\n", name, kind)
  67 }
  68
  69 func (e *Exporter) row(w http.ResponseWriter, name string, group []label.Label, extra string, value interface{}) {
  70         fmt.Fprint(w, name)
  71         buf := &bytes.Buffer{}
  72         fmt.Fprint(buf, group)
  73         if extra != "" {
  74                 if buf.Len() > 0 {
  75                         fmt.Fprint(buf, ",")
  76                 }
  77                 fmt.Fprint(buf, extra)
  78         }
  79         if buf.Len() > 0 {
  80                 fmt.Fprint(w, "{")
  81                 buf.WriteTo(w)
  82                 fmt.Fprint(w, "}")
  83         }
  84         fmt.Fprintf(w, " %v\n", value)
  85 }
  86
  87 func (e *Exporter) Serve(w http.ResponseWriter, r *http.Request) {
  88         e.mu.Lock()
  89         defer e.mu.Unlock()
  90         for _, data := range e.metrics {
  91                 switch data := data.(type) {
  92                 case *metric.Int64Data:
  93                         e.header(w, data.Info.Name, data.Info.Description, data.IsGauge, false)
  94                         for i, group := range data.Groups() {
  95                                 e.row(w, data.Info.Name, group, "", data.Rows[i])
  96                         }
  97
  98                 case *metric.Float64Data:
  99                         e.header(w, data.Info.Name, data.Info.Description, data.IsGauge, false)
 100                         for i, group := range data.Groups() {
 101                                 e.row(w, data.Info.Name, group, "", data.Rows[i])
 102                         }
 103
 104                 case *metric.HistogramInt64Data:
 105                         e.header(w, data.Info.Name, data.Info.Description, false, true)
 106                         for i, group := range data.Groups() {
 107                                 row := data.Rows[i]
 108                                 for j, b := range data.Info.Buckets {
 109                                         e.row(w, data.Info.Name+"_bucket", group, fmt.Sprintf(`le="%v"`, b), row.Values[j])
 110                                 }
 111                                 e.row(w, data.Info.Name+"_bucket", group, `le="+Inf"`, row.Count)
 112                                 e.row(w, data.Info.Name+"_count", group, "", row.Count)
 113                                 e.row(w, data.Info.Name+"_sum", group, "", row.Sum)
 114                         }
 115
 116                 case *metric.HistogramFloat64Data:
 117                         e.header(w, data.Info.Name, data.Info.Description, false, true)
 118                         for i, group := range data.Groups() {
 119                                 row := data.Rows[i]
 120                                 for j, b := range data.Info.Buckets {
 121                                         e.row(w, data.Info.Name+"_bucket", group, fmt.Sprintf(`le="%v"`, b), row.Values[j])
 122                                 }
 123                                 e.row(w, data.Info.Name+"_bucket", group, `le="+Inf"`, row.Count)
 124                                 e.row(w, data.Info.Name+"_count", group, "", row.Count)
 125                                 e.row(w, data.Info.Name+"_sum", group, "", row.Sum)
 126                         }
 127                 }
 128         }
 129 }