| 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, lm 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(lm).([]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 | } |
| 130 |
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