Add basictracer.Span interface to access basictracer detail.

Add basictracer.Tracer interface to access basictracer options.

debug.go

@@ -26,7 +26,7 @@ func (s *spanImpl) maybeAssertSanityLocked() {
 			msg: fmt.Sprintf("span used after Finish()"),
 		})
 	}
-	if s.tracer.Options.DebugAssertSingleGoroutine {
+	if s.tracer.options.DebugAssertSingleGoroutine {
 		startID := curGoroutineID()
 		curID, ok := s.raw.Tags[debugGoroutineIDTag].(uint64)
 		if !ok {

span.go

@@ -9,6 +9,22 @@ import (
 	"github.com/opentracing/opentracing-go/ext"
 )
 
+// Span provides access to the essential details of the span, for use
+// by basictracer consumers.  These methods may only be called prior
+// to (*opentracing.Span).Finish().
+type Span interface {
+	opentracing.Span
+
+	// Context contains trace identifiers
+	Context() Context
+
+	// Operation names the work done by this span instance
+	Operation() string
+
+	// Start indicates when the span began
+	Start() time.Time
+}
+
 // Implements the `Span` interface. Created via tracerImpl (see
 // `basictracer.New()`).
 type spanImpl struct {
@@ -50,7 +66,7 @@ func (s *spanImpl) SetOperationName(operationName string) opentracing.Span {
 }
 
 func (s *spanImpl) trim() bool {
-	return !s.raw.Sampled && s.tracer.TrimUnsampledSpans
+	return !s.raw.Sampled && s.tracer.options.TrimUnsampledSpans
 }
 
 func (s *spanImpl) SetTag(key string, value interface{}) opentracing.Span {
@@ -119,8 +135,8 @@ func (s *spanImpl) FinishWithOptions(opts opentracing.FinishOptions) {
 	s.raw.Duration = duration
 
 	s.onFinish(s.raw)
-	s.tracer.Recorder.RecordSpan(s.raw)
-	if s.tracer.Options.DebugAssertUseAfterFinish {
+	s.tracer.options.Recorder.RecordSpan(s.raw)
+	if s.tracer.options.DebugAssertUseAfterFinish {
 		// This makes it much more likely to catch a panic on any subsequent
 		// operation since s.tracer is accessed on every call to `Lock`.
 		s.reset()
@@ -163,3 +179,15 @@ func (s *spanImpl) BaggageItem(restrictedKey string) string {
 func (s *spanImpl) Tracer() opentracing.Tracer {
 	return s.tracer
 }
+
+func (s *spanImpl) Context() Context {
+	return s.raw.Context
+}
+
+func (s *spanImpl) Operation() string {
+	return s.raw.Operation
+}
+
+func (s *spanImpl) Start() time.Time {
+	return s.raw.Start
+}

tracer.go

@@ -6,6 +6,15 @@ import (
 	opentracing "github.com/opentracing/opentracing-go"
 )
 
+// Tracer extends the opentracing.Tracer interface with methods to
+// probe implementation state, for use by basictracer consumers.
+type Tracer interface {
+	opentracing.Tracer
+
+	// Options gets the Options used in New() or NewWithOptions().
+	Options() Options
+}
+
 // Options allows creating a customized Tracer via NewWithOptions. The object
 // must not be updated when there is an active tracer using it.
 type Options struct {
@@ -78,7 +87,7 @@ func DefaultOptions() Options {
 
 // NewWithOptions creates a customized Tracer.
 func NewWithOptions(opts Options) opentracing.Tracer {
-	rval := &tracerImpl{Options: opts}
+	rval := &tracerImpl{options: opts}
 	rval.textPropagator = &textMapPropagator{rval}
 	rval.binaryPropagator = &binaryPropagator{rval}
 	rval.accessorPropagator = &accessorPropagator{rval}
@@ -97,7 +106,7 @@ func New(recorder SpanRecorder) opentracing.Tracer {
 
 // Implements the `Tracer` interface.
 type tracerImpl struct {
-	Options
+	options            Options
 	textPropagator     *textMapPropagator
 	binaryPropagator   *binaryPropagator
 	accessorPropagator *accessorPropagator
@@ -135,7 +144,7 @@ func (t *tracerImpl) StartSpanWithOptions(
 	sp := t.getSpan()
 	if opts.Parent == nil {
 		sp.raw.TraceID, sp.raw.SpanID = randomID2()
-		sp.raw.Sampled = t.ShouldSample(sp.raw.TraceID)
+		sp.raw.Sampled = t.options.ShouldSample(sp.raw.TraceID)
 	} else {
 		pr := opts.Parent.(*spanImpl)
 		sp.raw.TraceID = pr.raw.TraceID
@@ -168,12 +177,12 @@ func (t *tracerImpl) startSpanInternal(
 	tags opentracing.Tags,
 ) opentracing.Span {
 	sp.tracer = t
-	sp.event = t.NewSpanEventListener()
+	sp.event = t.options.NewSpanEventListener()
 	sp.raw.Operation = operationName
 	sp.raw.Start = startTime
 	sp.raw.Duration = -1
 	sp.raw.Tags = tags
-	if t.Options.DebugAssertSingleGoroutine {
+	if t.options.DebugAssertSingleGoroutine {
 		sp.SetTag(debugGoroutineIDTag, curGoroutineID())
 	}
 	defer sp.onCreate(operationName)
@@ -210,3 +219,7 @@ func (t *tracerImpl) Join(operationName string, format interface{}, carrier inte
 	}
 	return nil, opentracing.ErrUnsupportedFormat
 }
+
+func (t *tracerImpl) Options() Options {
+	return t.options
+}