span.go

package work

import (
	"runtime"

	opentracing "github.com/opentracing/opentracing-go"
	"github.com/opentracing/opentracing-go/ext"
)

// StartSpan will start a new span with no parent span.
func StartSpan(operationName string) opentracing.Span {
	return StartSpanWithParent(nil, operationName)
}

// StartSpanWithParent will start a new span with a parent span.
// example:
//      span:= StartSpanWithParent(c.Get("tracing-context"),
func StartSpanWithParent(parent opentracing.SpanContext, operationName string) opentracing.Span {
	options := []opentracing.StartSpanOption{
		opentracing.Tag{Key: ext.SpanKindRPCServer.Key, Value: ext.SpanKindRPCServer.Value},
		opentracing.Tag{Key: "current-goroutines", Value: runtime.NumGoroutine()},
	}

	if parent != nil {
		options = append(options, opentracing.ChildOf(parent))
	}

	return opentracing.StartSpan(operationName, options...)
}