.config/coc/extensions/coc-go-data/tools/pkg/mod/golang.org/x/tools@v0.0.0-20201028153306-37f0764111ff/internal/event/export/metric/exporter.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 metric aggregates events into metrics that can be exported.
   6 package metric
   7
   8 import (
   9         "context"
  10         "sync"
  11         "time"
  12
  13         "golang.org/x/tools/internal/event"
  14         "golang.org/x/tools/internal/event/core"
  15         "golang.org/x/tools/internal/event/keys"
  16         "golang.org/x/tools/internal/event/label"
  17 )
  18
  19 var Entries = keys.New("metric_entries", "The set of metrics calculated for an event")
  20
  21 type Config struct {
  22         subscribers map[interface{}][]subscriber
  23 }
  24
  25 type subscriber func(time.Time, label.Map, label.Label) Data
  26
  27 func (e *Config) subscribe(key label.Key, s subscriber) {
  28         if e.subscribers == nil {
  29                 e.subscribers = make(map[interface{}][]subscriber)
  30         }
  31         e.subscribers[key] = append(e.subscribers[key], s)
  32 }
  33
  34 func (e *Config) Exporter(output event.Exporter) event.Exporter {
  35         var mu sync.Mutex
  36         return func(ctx context.Context, ev core.Event, lm label.Map) context.Context {
  37                 if !event.IsMetric(ev) {
  38                         return output(ctx, ev, lm)
  39                 }
  40                 mu.Lock()
  41                 defer mu.Unlock()
  42                 var metrics []Data
  43                 for index := 0; ev.Valid(index); index++ {
  44                         l := ev.Label(index)
  45                         if !l.Valid() {
  46                                 continue
  47                         }
  48                         id := l.Key()
  49                         if list := e.subscribers[id]; len(list) > 0 {
  50                                 for _, s := range list {
  51                                         metrics = append(metrics, s(ev.At(), lm, l))
  52                                 }
  53                         }
  54                 }
  55                 lm = label.MergeMaps(label.NewMap(Entries.Of(metrics)), lm)
  56                 return output(ctx, ev, lm)
  57         }
  58 }