docs/vendor/github.com/cloudevents/sdk-go/v2/client/observability.go

95 lines
2.7 KiB
Go

package client
import (
"context"
"github.com/cloudevents/sdk-go/v2/event"
"github.com/cloudevents/sdk-go/v2/extensions"
"github.com/cloudevents/sdk-go/v2/observability"
"go.opencensus.io/stats"
"go.opencensus.io/stats/view"
"go.opencensus.io/trace"
)
var (
// LatencyMs measures the latency in milliseconds for the CloudEvents
// client methods.
LatencyMs = stats.Float64("cloudevents.io/sdk-go/client/latency", "The latency in milliseconds for the CloudEvents client methods.", "ms")
)
var (
// LatencyView is an OpenCensus view that shows client method latency.
LatencyView = &view.View{
Name: "client/latency",
Measure: LatencyMs,
Description: "The distribution of latency inside of client for CloudEvents.",
Aggregation: view.Distribution(0, .01, .1, 1, 10, 100, 1000, 10000),
TagKeys: observability.LatencyTags(),
}
)
type observed int32
// Adheres to Observable
var _ observability.Observable = observed(0)
const (
specversionAttr = "cloudevents.specversion"
typeAttr = "cloudevents.type"
sourceAttr = "cloudevents.source"
subjectAttr = "cloudevents.subject"
datacontenttypeAttr = "cloudevents.datacontenttype"
reportSend observed = iota
reportRequest
reportStartReceiver
)
// MethodName implements Observable.MethodName
func (o observed) MethodName() string {
switch o {
case reportSend:
return "send"
case reportRequest:
return "request"
case reportStartReceiver:
return "start_receiver"
default:
return "unknown"
}
}
// LatencyMs implements Observable.LatencyMs
func (o observed) LatencyMs() *stats.Float64Measure {
return LatencyMs
}
func EventTraceAttributes(e event.EventReader) []trace.Attribute {
as := []trace.Attribute{
trace.StringAttribute(specversionAttr, e.SpecVersion()),
trace.StringAttribute(typeAttr, e.Type()),
trace.StringAttribute(sourceAttr, e.Source()),
}
if sub := e.Subject(); sub != "" {
as = append(as, trace.StringAttribute(subjectAttr, sub))
}
if dct := e.DataContentType(); dct != "" {
as = append(as, trace.StringAttribute(datacontenttypeAttr, dct))
}
return as
}
// TraceSpan returns context and trace.Span based on event. Caller must call span.End()
func TraceSpan(ctx context.Context, e event.Event) (context.Context, *trace.Span) {
var span *trace.Span
if ext, ok := extensions.GetDistributedTracingExtension(e); ok {
ctx, span = ext.StartChildSpan(ctx, observability.ClientSpanName, trace.WithSpanKind(trace.SpanKindServer))
}
if span == nil {
ctx, span = trace.StartSpan(ctx, observability.ClientSpanName, trace.WithSpanKind(trace.SpanKindServer))
}
if span.IsRecordingEvents() {
span.AddAttributes(EventTraceAttributes(&e)...)
}
return ctx, span
}