gtsocial-umbx

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event.go (4464B)

      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 event
      6 
      7 import (
      8 	"context"
      9 
     10 	"golang.org/x/tools/internal/event/core"
     11 	"golang.org/x/tools/internal/event/keys"
     12 	"golang.org/x/tools/internal/event/label"
     13 )
     14 
     15 // Exporter is a function that handles events.
     16 // It may return a modified context and event.
     17 type Exporter func(context.Context, core.Event, label.Map) context.Context
     18 
     19 // SetExporter sets the global exporter function that handles all events.
     20 // The exporter is called synchronously from the event call site, so it should
     21 // return quickly so as not to hold up user code.
     22 func SetExporter(e Exporter) {
     23 	core.SetExporter(core.Exporter(e))
     24 }
     25 
     26 // Log takes a message and a label list and combines them into a single event
     27 // before delivering them to the exporter.
     28 func Log(ctx context.Context, message string, labels ...label.Label) {
     29 	core.Export(ctx, core.MakeEvent([3]label.Label{
     30 		keys.Msg.Of(message),
     31 	}, labels))
     32 }
     33 
     34 // IsLog returns true if the event was built by the Log function.
     35 // It is intended to be used in exporters to identify the semantics of the
     36 // event when deciding what to do with it.
     37 func IsLog(ev core.Event) bool {
     38 	return ev.Label(0).Key() == keys.Msg
     39 }
     40 
     41 // Error takes a message and a label list and combines them into a single event
     42 // before delivering them to the exporter. It captures the error in the
     43 // delivered event.
     44 func Error(ctx context.Context, message string, err error, labels ...label.Label) {
     45 	core.Export(ctx, core.MakeEvent([3]label.Label{
     46 		keys.Msg.Of(message),
     47 		keys.Err.Of(err),
     48 	}, labels))
     49 }
     50 
     51 // IsError returns true if the event was built by the Error function.
     52 // It is intended to be used in exporters to identify the semantics of the
     53 // event when deciding what to do with it.
     54 func IsError(ev core.Event) bool {
     55 	return ev.Label(0).Key() == keys.Msg &&
     56 		ev.Label(1).Key() == keys.Err
     57 }
     58 
     59 // Metric sends a label event to the exporter with the supplied labels.
     60 func Metric(ctx context.Context, labels ...label.Label) {
     61 	core.Export(ctx, core.MakeEvent([3]label.Label{
     62 		keys.Metric.New(),
     63 	}, labels))
     64 }
     65 
     66 // IsMetric returns true if the event was built by the Metric function.
     67 // It is intended to be used in exporters to identify the semantics of the
     68 // event when deciding what to do with it.
     69 func IsMetric(ev core.Event) bool {
     70 	return ev.Label(0).Key() == keys.Metric
     71 }
     72 
     73 // Label sends a label event to the exporter with the supplied labels.
     74 func Label(ctx context.Context, labels ...label.Label) context.Context {
     75 	return core.Export(ctx, core.MakeEvent([3]label.Label{
     76 		keys.Label.New(),
     77 	}, labels))
     78 }
     79 
     80 // IsLabel returns true if the event was built by the Label function.
     81 // It is intended to be used in exporters to identify the semantics of the
     82 // event when deciding what to do with it.
     83 func IsLabel(ev core.Event) bool {
     84 	return ev.Label(0).Key() == keys.Label
     85 }
     86 
     87 // Start sends a span start event with the supplied label list to the exporter.
     88 // It also returns a function that will end the span, which should normally be
     89 // deferred.
     90 func Start(ctx context.Context, name string, labels ...label.Label) (context.Context, func()) {
     91 	return core.ExportPair(ctx,
     92 		core.MakeEvent([3]label.Label{
     93 			keys.Start.Of(name),
     94 		}, labels),
     95 		core.MakeEvent([3]label.Label{
     96 			keys.End.New(),
     97 		}, nil))
     98 }
     99 
    100 // IsStart returns true if the event was built by the Start function.
    101 // It is intended to be used in exporters to identify the semantics of the
    102 // event when deciding what to do with it.
    103 func IsStart(ev core.Event) bool {
    104 	return ev.Label(0).Key() == keys.Start
    105 }
    106 
    107 // IsEnd returns true if the event was built by the End function.
    108 // It is intended to be used in exporters to identify the semantics of the
    109 // event when deciding what to do with it.
    110 func IsEnd(ev core.Event) bool {
    111 	return ev.Label(0).Key() == keys.End
    112 }
    113 
    114 // Detach returns a context without an associated span.
    115 // This allows the creation of spans that are not children of the current span.
    116 func Detach(ctx context.Context) context.Context {
    117 	return core.Export(ctx, core.MakeEvent([3]label.Label{
    118 		keys.Detach.New(),
    119 	}, nil))
    120 }
    121 
    122 // IsDetach returns true if the event was built by the Detach function.
    123 // It is intended to be used in exporters to identify the semantics of the
    124 // event when deciding what to do with it.
    125 func IsDetach(ev core.Event) bool {
    126 	return ev.Label(0).Key() == keys.Detach
    127 }