Bump github.com/spf13/cobra to v1.2.1

Fixes #9730

Signed-off-by: Paul Holzinger <pholzing@redhat.com>

5 files changed, 376 insertions, 102 deletions

diff --git a/vendor/go.opencensus.io/trace/basetypes.go b/vendor/go.opencensus.io/trace/basetypes.go
index 0c54492a2..c8e26ed63 100644
--- a/vendor/go.opencensus.io/trace/basetypes.go
+++ b/vendor/go.opencensus.io/trace/basetypes.go
@@ -49,6 +49,16 @@ type Attribute struct {
 	value interface{}
 }
 
+// Key returns the attribute's key
+func (a *Attribute) Key() string {
+	return a.key
+}
+
+// Value returns the attribute's value
+func (a *Attribute) Value() interface{} {
+	return a.value
+}
+
 // BoolAttribute returns a bool-valued attribute.
 func BoolAttribute(key string, value bool) Attribute {
 	return Attribute{key: key, value: value}
diff --git a/vendor/go.opencensus.io/trace/lrumap.go b/vendor/go.opencensus.io/trace/lrumap.go
index dc7a295c7..908c2497e 100644
--- a/vendor/go.opencensus.io/trace/lrumap.go
+++ b/vendor/go.opencensus.io/trace/lrumap.go
@@ -44,7 +44,7 @@ func (lm lruMap) len() int {
 }
 
 func (lm lruMap) keys() []interface{} {
-	keys := []interface{}{}
+	keys := make([]interface{}, len(lm.cacheKeys))
 	for k := range lm.cacheKeys {
 		keys = append(keys, k)
 	}
diff --git a/vendor/go.opencensus.io/trace/spanstore.go b/vendor/go.opencensus.io/trace/spanstore.go
index c442d9902..e601f76f2 100644
--- a/vendor/go.opencensus.io/trace/spanstore.go
+++ b/vendor/go.opencensus.io/trace/spanstore.go
@@ -48,8 +48,10 @@ func (i internalOnly) ReportActiveSpans(name string) []*SpanData {
 	var out []*SpanData
 	s.mu.Lock()
 	defer s.mu.Unlock()
-	for span := range s.active {
-		out = append(out, span.makeSpanData())
+	for activeSpan := range s.active {
+		if s, ok := activeSpan.(*span); ok {
+			out = append(out, s.makeSpanData())
+		}
 	}
 	return out
 }
@@ -185,7 +187,7 @@ func (i internalOnly) ReportSpansByLatency(name string, minLatency, maxLatency t
 // bucketed by latency.
 type spanStore struct {
 	mu                     sync.Mutex // protects everything below.
-	active                 map[*Span]struct{}
+	active                 map[SpanInterface]struct{}
 	errors                 map[int32]*bucket
 	latency                []bucket
 	maxSpansPerErrorBucket int
@@ -194,7 +196,7 @@ type spanStore struct {
 // newSpanStore creates a span store.
 func newSpanStore(name string, latencyBucketSize int, errorBucketSize int) *spanStore {
 	s := &spanStore{
-		active:                 make(map[*Span]struct{}),
+		active:                 make(map[SpanInterface]struct{}),
 		latency:                make([]bucket, len(defaultLatencies)+1),
 		maxSpansPerErrorBucket: errorBucketSize,
 	}
@@ -271,7 +273,7 @@ func (s *spanStore) resize(latencyBucketSize int, errorBucketSize int) {
 }
 
 // add adds a span to the active bucket of the spanStore.
-func (s *spanStore) add(span *Span) {
+func (s *spanStore) add(span SpanInterface) {
 	s.mu.Lock()
 	s.active[span] = struct{}{}
 	s.mu.Unlock()
@@ -279,7 +281,7 @@ func (s *spanStore) add(span *Span) {
 
 // finished removes a span from the active set, and adds a corresponding
 // SpanData to a latency or error bucket.
-func (s *spanStore) finished(span *Span, sd *SpanData) {
+func (s *spanStore) finished(span SpanInterface, sd *SpanData) {
 	latency := sd.EndTime.Sub(sd.StartTime)
 	if latency < 0 {
 		latency = 0
diff --git a/vendor/go.opencensus.io/trace/trace.go b/vendor/go.opencensus.io/trace/trace.go
index 3f8977b41..861df9d39 100644
--- a/vendor/go.opencensus.io/trace/trace.go
+++ b/vendor/go.opencensus.io/trace/trace.go
@@ -28,12 +28,16 @@ import (
 	"go.opencensus.io/trace/tracestate"
 )
 
+type tracer struct{}
+
+var _ Tracer = &tracer{}
+
 // Span represents a span of a trace.  It has an associated SpanContext, and
 // stores data accumulated while the span is active.
 //
 // Ideally users should interact with Spans by calling the functions in this
 // package that take a Context parameter.
-type Span struct {
+type span struct {
 	// data contains information recorded about the span.
 	//
 	// It will be non-nil if we are exporting the span or recording events for it.
@@ -66,7 +70,7 @@ type Span struct {
 // IsRecordingEvents returns true if events are being recorded for this span.
 // Use this check to avoid computing expensive annotations when they will never
 // be used.
-func (s *Span) IsRecordingEvents() bool {
+func (s *span) IsRecordingEvents() bool {
 	if s == nil {
 		return false
 	}
@@ -109,13 +113,13 @@ type SpanContext struct {
 type contextKey struct{}
 
 // FromContext returns the Span stored in a context, or nil if there isn't one.
-func FromContext(ctx context.Context) *Span {
+func (t *tracer) FromContext(ctx context.Context) *Span {
 	s, _ := ctx.Value(contextKey{}).(*Span)
 	return s
 }
 
 // NewContext returns a new context with the given Span attached.
-func NewContext(parent context.Context, s *Span) context.Context {
+func (t *tracer) NewContext(parent context.Context, s *Span) context.Context {
 	return context.WithValue(parent, contextKey{}, s)
 }
 
@@ -166,12 +170,14 @@ func WithSampler(sampler Sampler) StartOption {
 //
 // Returned context contains the newly created span. You can use it to
 // propagate the returned span in process.
-func StartSpan(ctx context.Context, name string, o ...StartOption) (context.Context, *Span) {
+func (t *tracer) StartSpan(ctx context.Context, name string, o ...StartOption) (context.Context, *Span) {
 	var opts StartOptions
 	var parent SpanContext
-	if p := FromContext(ctx); p != nil {
-		p.addChild()
-		parent = p.spanContext
+	if p := t.FromContext(ctx); p != nil {
+		if ps, ok := p.internal.(*span); ok {
+			ps.addChild()
+		}
+		parent = p.SpanContext()
 	}
 	for _, op := range o {
 		op(&opts)
@@ -180,7 +186,8 @@ func StartSpan(ctx context.Context, name string, o ...StartOption) (context.Cont
 
 	ctx, end := startExecutionTracerTask(ctx, name)
 	span.executionTracerTaskEnd = end
-	return NewContext(ctx, span), span
+	extSpan := NewSpan(span)
+	return t.NewContext(ctx, extSpan), extSpan
 }
 
 // StartSpanWithRemoteParent starts a new child span of the span from the given parent.
@@ -190,7 +197,7 @@ func StartSpan(ctx context.Context, name string, o ...StartOption) (context.Cont
 //
 // Returned context contains the newly created span. You can use it to
 // propagate the returned span in process.
-func StartSpanWithRemoteParent(ctx context.Context, name string, parent SpanContext, o ...StartOption) (context.Context, *Span) {
+func (t *tracer) StartSpanWithRemoteParent(ctx context.Context, name string, parent SpanContext, o ...StartOption) (context.Context, *Span) {
 	var opts StartOptions
 	for _, op := range o {
 		op(&opts)
@@ -198,19 +205,24 @@ func StartSpanWithRemoteParent(ctx context.Context, name string, parent SpanCont
 	span := startSpanInternal(name, parent != SpanContext{}, parent, true, opts)
 	ctx, end := startExecutionTracerTask(ctx, name)
 	span.executionTracerTaskEnd = end
-	return NewContext(ctx, span), span
+	extSpan := NewSpan(span)
+	return t.NewContext(ctx, extSpan), extSpan
 }
 
-func startSpanInternal(name string, hasParent bool, parent SpanContext, remoteParent bool, o StartOptions) *Span {
-	span := &Span{}
-	span.spanContext = parent
+func startSpanInternal(name string, hasParent bool, parent SpanContext, remoteParent bool, o StartOptions) *span {
+	s := &span{}
+	s.spanContext = parent
 
 	cfg := config.Load().(*Config)
+	if gen, ok := cfg.IDGenerator.(*defaultIDGenerator); ok {
+		// lazy initialization
+		gen.init()
+	}
 
 	if !hasParent {
-		span.spanContext.TraceID = cfg.IDGenerator.NewTraceID()
+		s.spanContext.TraceID = cfg.IDGenerator.NewTraceID()
 	}
-	span.spanContext.SpanID = cfg.IDGenerator.NewSpanID()
+	s.spanContext.SpanID = cfg.IDGenerator.NewSpanID()
 	sampler := cfg.DefaultSampler
 
 	if !hasParent || remoteParent || o.Sampler != nil {
@@ -222,47 +234,47 @@ func startSpanInternal(name string, hasParent bool, parent SpanContext, remotePa
 		if o.Sampler != nil {
 			sampler = o.Sampler
 		}
-		span.spanContext.setIsSampled(sampler(SamplingParameters{
+		s.spanContext.setIsSampled(sampler(SamplingParameters{
 			ParentContext:   parent,
-			TraceID:         span.spanContext.TraceID,
-			SpanID:          span.spanContext.SpanID,
+			TraceID:         s.spanContext.TraceID,
+			SpanID:          s.spanContext.SpanID,
 			Name:            name,
 			HasRemoteParent: remoteParent}).Sample)
 	}
 
-	if !internal.LocalSpanStoreEnabled && !span.spanContext.IsSampled() {
-		return span
+	if !internal.LocalSpanStoreEnabled && !s.spanContext.IsSampled() {
+		return s
 	}
 
-	span.data = &SpanData{
-		SpanContext:     span.spanContext,
+	s.data = &SpanData{
+		SpanContext:     s.spanContext,
 		StartTime:       time.Now(),
 		SpanKind:        o.SpanKind,
 		Name:            name,
 		HasRemoteParent: remoteParent,
 	}
-	span.lruAttributes = newLruMap(cfg.MaxAttributesPerSpan)
-	span.annotations = newEvictedQueue(cfg.MaxAnnotationEventsPerSpan)
-	span.messageEvents = newEvictedQueue(cfg.MaxMessageEventsPerSpan)
-	span.links = newEvictedQueue(cfg.MaxLinksPerSpan)
+	s.lruAttributes = newLruMap(cfg.MaxAttributesPerSpan)
+	s.annotations = newEvictedQueue(cfg.MaxAnnotationEventsPerSpan)
+	s.messageEvents = newEvictedQueue(cfg.MaxMessageEventsPerSpan)
+	s.links = newEvictedQueue(cfg.MaxLinksPerSpan)
 
 	if hasParent {
-		span.data.ParentSpanID = parent.SpanID
+		s.data.ParentSpanID = parent.SpanID
 	}
 	if internal.LocalSpanStoreEnabled {
 		var ss *spanStore
 		ss = spanStoreForNameCreateIfNew(name)
 		if ss != nil {
-			span.spanStore = ss
-			ss.add(span)
+			s.spanStore = ss
+			ss.add(s)
 		}
 	}
 
-	return span
+	return s
 }
 
 // End ends the span.
-func (s *Span) End() {
+func (s *span) End() {
 	if s == nil {
 		return
 	}
@@ -292,7 +304,7 @@ func (s *Span) End() {
 
 // makeSpanData produces a SpanData representing the current state of the Span.
 // It requires that s.data is non-nil.
-func (s *Span) makeSpanData() *SpanData {
+func (s *span) makeSpanData() *SpanData {
 	var sd SpanData
 	s.mu.Lock()
 	sd = *s.data
@@ -317,7 +329,7 @@ func (s *Span) makeSpanData() *SpanData {
 }
 
 // SpanContext returns the SpanContext of the span.
-func (s *Span) SpanContext() SpanContext {
+func (s *span) SpanContext() SpanContext {
 	if s == nil {
 		return SpanContext{}
 	}
@@ -325,7 +337,7 @@ func (s *Span) SpanContext() SpanContext {
 }
 
 // SetName sets the name of the span, if it is recording events.
-func (s *Span) SetName(name string) {
+func (s *span) SetName(name string) {
 	if !s.IsRecordingEvents() {
 		return
 	}
@@ -335,7 +347,7 @@ func (s *Span) SetName(name string) {
 }
 
 // SetStatus sets the status of the span, if it is recording events.
-func (s *Span) SetStatus(status Status) {
+func (s *span) SetStatus(status Status) {
 	if !s.IsRecordingEvents() {
 		return
 	}
@@ -344,32 +356,32 @@ func (s *Span) SetStatus(status Status) {
 	s.mu.Unlock()
 }
 
-func (s *Span) interfaceArrayToLinksArray() []Link {
-	linksArr := make([]Link, 0)
+func (s *span) interfaceArrayToLinksArray() []Link {
+	linksArr := make([]Link, 0, len(s.links.queue))
 	for _, value := range s.links.queue {
 		linksArr = append(linksArr, value.(Link))
 	}
 	return linksArr
 }
 
-func (s *Span) interfaceArrayToMessageEventArray() []MessageEvent {
-	messageEventArr := make([]MessageEvent, 0)
+func (s *span) interfaceArrayToMessageEventArray() []MessageEvent {
+	messageEventArr := make([]MessageEvent, 0, len(s.messageEvents.queue))
 	for _, value := range s.messageEvents.queue {
 		messageEventArr = append(messageEventArr, value.(MessageEvent))
 	}
 	return messageEventArr
 }
 
-func (s *Span) interfaceArrayToAnnotationArray() []Annotation {
-	annotationArr := make([]Annotation, 0)
+func (s *span) interfaceArrayToAnnotationArray() []Annotation {
+	annotationArr := make([]Annotation, 0, len(s.annotations.queue))
 	for _, value := range s.annotations.queue {
 		annotationArr = append(annotationArr, value.(Annotation))
 	}
 	return annotationArr
 }
 
-func (s *Span) lruAttributesToAttributeMap() map[string]interface{} {
-	attributes := make(map[string]interface{})
+func (s *span) lruAttributesToAttributeMap() map[string]interface{} {
+	attributes := make(map[string]interface{}, s.lruAttributes.len())
 	for _, key := range s.lruAttributes.keys() {
 		value, ok := s.lruAttributes.get(key)
 		if ok {
@@ -380,13 +392,13 @@ func (s *Span) lruAttributesToAttributeMap() map[string]interface{} {
 	return attributes
 }
 
-func (s *Span) copyToCappedAttributes(attributes []Attribute) {
+func (s *span) copyToCappedAttributes(attributes []Attribute) {
 	for _, a := range attributes {
 		s.lruAttributes.add(a.key, a.value)
 	}
 }
 
-func (s *Span) addChild() {
+func (s *span) addChild() {
 	if !s.IsRecordingEvents() {
 		return
 	}
@@ -398,7 +410,7 @@ func (s *Span) addChild() {
 // AddAttributes sets attributes in the span.
 //
 // Existing attributes whose keys appear in the attributes parameter are overwritten.
-func (s *Span) AddAttributes(attributes ...Attribute) {
+func (s *span) AddAttributes(attributes ...Attribute) {
 	if !s.IsRecordingEvents() {
 		return
 	}
@@ -407,49 +419,27 @@ func (s *Span) AddAttributes(attributes ...Attribute) {
 	s.mu.Unlock()
 }
 
-// copyAttributes copies a slice of Attributes into a map.
-func copyAttributes(m map[string]interface{}, attributes []Attribute) {
-	for _, a := range attributes {
-		m[a.key] = a.value
-	}
-}
-
-func (s *Span) lazyPrintfInternal(attributes []Attribute, format string, a ...interface{}) {
+func (s *span) printStringInternal(attributes []Attribute, str string) {
 	now := time.Now()
-	msg := fmt.Sprintf(format, a...)
-	var m map[string]interface{}
-	s.mu.Lock()
+	var am map[string]interface{}
 	if len(attributes) != 0 {
-		m = make(map[string]interface{})
-		copyAttributes(m, attributes)
+		am = make(map[string]interface{}, len(attributes))
+		for _, attr := range attributes {
+			am[attr.key] = attr.value
+		}
 	}
-	s.annotations.add(Annotation{
-		Time:       now,
-		Message:    msg,
-		Attributes: m,
-	})
-	s.mu.Unlock()
-}
-
-func (s *Span) printStringInternal(attributes []Attribute, str string) {
-	now := time.Now()
-	var a map[string]interface{}
 	s.mu.Lock()
-	if len(attributes) != 0 {
-		a = make(map[string]interface{})
-		copyAttributes(a, attributes)
-	}
 	s.annotations.add(Annotation{
 		Time:       now,
 		Message:    str,
-		Attributes: a,
+		Attributes: am,
 	})
 	s.mu.Unlock()
 }
 
 // Annotate adds an annotation with attributes.
 // Attributes can be nil.
-func (s *Span) Annotate(attributes []Attribute, str string) {
+func (s *span) Annotate(attributes []Attribute, str string) {
 	if !s.IsRecordingEvents() {
 		return
 	}
@@ -457,11 +447,11 @@ func (s *Span) Annotate(attributes []Attribute, str string) {
 }
 
 // Annotatef adds an annotation with attributes.
-func (s *Span) Annotatef(attributes []Attribute, format string, a ...interface{}) {
+func (s *span) Annotatef(attributes []Attribute, format string, a ...interface{}) {
 	if !s.IsRecordingEvents() {
 		return
 	}
-	s.lazyPrintfInternal(attributes, format, a...)
+	s.printStringInternal(attributes, fmt.Sprintf(format, a...))
 }
 
 // AddMessageSendEvent adds a message send event to the span.
@@ -470,7 +460,7 @@ func (s *Span) Annotatef(attributes []Attribute, format string, a ...interface{}
 // unique in this span and the same between the send event and the receive
 // event (this allows to identify a message between the sender and receiver).
 // For example, this could be a sequence id.
-func (s *Span) AddMessageSendEvent(messageID, uncompressedByteSize, compressedByteSize int64) {
+func (s *span) AddMessageSendEvent(messageID, uncompressedByteSize, compressedByteSize int64) {
 	if !s.IsRecordingEvents() {
 		return
 	}
@@ -492,7 +482,7 @@ func (s *Span) AddMessageSendEvent(messageID, uncompressedByteSize, compressedBy
 // unique in this span and the same between the send event and the receive
 // event (this allows to identify a message between the sender and receiver).
 // For example, this could be a sequence id.
-func (s *Span) AddMessageReceiveEvent(messageID, uncompressedByteSize, compressedByteSize int64) {
+func (s *span) AddMessageReceiveEvent(messageID, uncompressedByteSize, compressedByteSize int64) {
 	if !s.IsRecordingEvents() {
 		return
 	}
@@ -509,7 +499,7 @@ func (s *Span) AddMessageReceiveEvent(messageID, uncompressedByteSize, compresse
 }
 
 // AddLink adds a link to the span.
-func (s *Span) AddLink(l Link) {
+func (s *span) AddLink(l Link) {
 	if !s.IsRecordingEvents() {
 		return
 	}
@@ -518,7 +508,7 @@ func (s *Span) AddLink(l Link) {
 	s.mu.Unlock()
 }
 
-func (s *Span) String() string {
+func (s *span) String() string {
 	if s == nil {
 		return "<nil>"
 	}
@@ -534,20 +524,9 @@ func (s *Span) String() string {
 var config atomic.Value // access atomically
 
 func init() {
-	gen := &defaultIDGenerator{}
-	// initialize traceID and spanID generators.
-	var rngSeed int64
-	for _, p := range []interface{}{
-		&rngSeed, &gen.traceIDAdd, &gen.nextSpanID, &gen.spanIDInc,
-	} {
-		binary.Read(crand.Reader, binary.LittleEndian, p)
-	}
-	gen.traceIDRand = rand.New(rand.NewSource(rngSeed))
-	gen.spanIDInc |= 1
-
 	config.Store(&Config{
 		DefaultSampler:             ProbabilitySampler(defaultSamplingProbability),
-		IDGenerator:                gen,
+		IDGenerator:                &defaultIDGenerator{},
 		MaxAttributesPerSpan:       DefaultMaxAttributesPerSpan,
 		MaxAnnotationEventsPerSpan: DefaultMaxAnnotationEventsPerSpan,
 		MaxMessageEventsPerSpan:    DefaultMaxMessageEventsPerSpan,
@@ -571,6 +550,24 @@ type defaultIDGenerator struct {
 
 	traceIDAdd  [2]uint64
 	traceIDRand *rand.Rand
+
+	initOnce sync.Once
+}
+
+// init initializes the generator on the first call to avoid consuming entropy
+// unnecessarily.
+func (gen *defaultIDGenerator) init() {
+	gen.initOnce.Do(func() {
+		// initialize traceID and spanID generators.
+		var rngSeed int64
+		for _, p := range []interface{}{
+			&rngSeed, &gen.traceIDAdd, &gen.nextSpanID, &gen.spanIDInc,
+		} {
+			binary.Read(crand.Reader, binary.LittleEndian, p)
+		}
+		gen.traceIDRand = rand.New(rand.NewSource(rngSeed))
+		gen.spanIDInc |= 1
+	})
 }
 
 // NewSpanID returns a non-zero span ID from a randomly-chosen sequence.
diff --git a/vendor/go.opencensus.io/trace/trace_api.go b/vendor/go.opencensus.io/trace/trace_api.go
new file mode 100644
index 000000000..9e2c3a999
--- /dev/null
+++ b/vendor/go.opencensus.io/trace/trace_api.go
@@ -0,0 +1,265 @@
+// Copyright 2020, OpenCensus Authors
+//
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+//     http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package trace
+
+import (
+	"context"
+)
+
+// DefaultTracer is the tracer used when package-level exported functions are invoked.
+var DefaultTracer Tracer = &tracer{}
+
+// Tracer can start spans and access context functions.
+type Tracer interface {
+
+	// StartSpan starts a new child span of the current span in the context. If
+	// there is no span in the context, creates a new trace and span.
+	//
+	// Returned context contains the newly created span. You can use it to
+	// propagate the returned span in process.
+	StartSpan(ctx context.Context, name string, o ...StartOption) (context.Context, *Span)
+
+	// StartSpanWithRemoteParent starts a new child span of the span from the given parent.
+	//
+	// If the incoming context contains a parent, it ignores. StartSpanWithRemoteParent is
+	// preferred for cases where the parent is propagated via an incoming request.
+	//
+	// Returned context contains the newly created span. You can use it to
+	// propagate the returned span in process.
+	StartSpanWithRemoteParent(ctx context.Context, name string, parent SpanContext, o ...StartOption) (context.Context, *Span)
+
+	// FromContext returns the Span stored in a context, or nil if there isn't one.
+	FromContext(ctx context.Context) *Span
+
+	// NewContext returns a new context with the given Span attached.
+	NewContext(parent context.Context, s *Span) context.Context
+}
+
+// StartSpan starts a new child span of the current span in the context. If
+// there is no span in the context, creates a new trace and span.
+//
+// Returned context contains the newly created span. You can use it to
+// propagate the returned span in process.
+func StartSpan(ctx context.Context, name string, o ...StartOption) (context.Context, *Span) {
+	return DefaultTracer.StartSpan(ctx, name, o...)
+}
+
+// StartSpanWithRemoteParent starts a new child span of the span from the given parent.
+//
+// If the incoming context contains a parent, it ignores. StartSpanWithRemoteParent is
+// preferred for cases where the parent is propagated via an incoming request.
+//
+// Returned context contains the newly created span. You can use it to
+// propagate the returned span in process.
+func StartSpanWithRemoteParent(ctx context.Context, name string, parent SpanContext, o ...StartOption) (context.Context, *Span) {
+	return DefaultTracer.StartSpanWithRemoteParent(ctx, name, parent, o...)
+}
+
+// FromContext returns the Span stored in a context, or a Span that is not
+// recording events if there isn't one.
+func FromContext(ctx context.Context) *Span {
+	return DefaultTracer.FromContext(ctx)
+}
+
+// NewContext returns a new context with the given Span attached.
+func NewContext(parent context.Context, s *Span) context.Context {
+	return DefaultTracer.NewContext(parent, s)
+}
+
+// SpanInterface represents a span of a trace.  It has an associated SpanContext, and
+// stores data accumulated while the span is active.
+//
+// Ideally users should interact with Spans by calling the functions in this
+// package that take a Context parameter.
+type SpanInterface interface {
+
+	// IsRecordingEvents returns true if events are being recorded for this span.
+	// Use this check to avoid computing expensive annotations when they will never
+	// be used.
+	IsRecordingEvents() bool
+
+	// End ends the span.
+	End()
+
+	// SpanContext returns the SpanContext of the span.
+	SpanContext() SpanContext
+
+	// SetName sets the name of the span, if it is recording events.
+	SetName(name string)
+
+	// SetStatus sets the status of the span, if it is recording events.
+	SetStatus(status Status)
+
+	// AddAttributes sets attributes in the span.
+	//
+	// Existing attributes whose keys appear in the attributes parameter are overwritten.
+	AddAttributes(attributes ...Attribute)
+
+	// Annotate adds an annotation with attributes.
+	// Attributes can be nil.
+	Annotate(attributes []Attribute, str string)
+
+	// Annotatef adds an annotation with attributes.
+	Annotatef(attributes []Attribute, format string, a ...interface{})
+
+	// AddMessageSendEvent adds a message send event to the span.
+	//
+	// messageID is an identifier for the message, which is recommended to be
+	// unique in this span and the same between the send event and the receive
+	// event (this allows to identify a message between the sender and receiver).
+	// For example, this could be a sequence id.
+	AddMessageSendEvent(messageID, uncompressedByteSize, compressedByteSize int64)
+
+	// AddMessageReceiveEvent adds a message receive event to the span.
+	//
+	// messageID is an identifier for the message, which is recommended to be
+	// unique in this span and the same between the send event and the receive
+	// event (this allows to identify a message between the sender and receiver).
+	// For example, this could be a sequence id.
+	AddMessageReceiveEvent(messageID, uncompressedByteSize, compressedByteSize int64)
+
+	// AddLink adds a link to the span.
+	AddLink(l Link)
+
+	// String prints a string representation of a span.
+	String() string
+}
+
+// NewSpan is a convenience function for creating a *Span out of a *span
+func NewSpan(s SpanInterface) *Span {
+	return &Span{internal: s}
+}
+
+// Span is a struct wrapper around the SpanInt interface, which allows correctly handling
+// nil spans, while also allowing the SpanInterface implementation to be swapped out.
+type Span struct {
+	internal SpanInterface
+}
+
+// Internal returns the underlying implementation of the Span
+func (s *Span) Internal() SpanInterface {
+	return s.internal
+}
+
+// IsRecordingEvents returns true if events are being recorded for this span.
+// Use this check to avoid computing expensive annotations when they will never
+// be used.
+func (s *Span) IsRecordingEvents() bool {
+	if s == nil {
+		return false
+	}
+	return s.internal.IsRecordingEvents()
+}
+
+// End ends the span.
+func (s *Span) End() {
+	if s == nil {
+		return
+	}
+	s.internal.End()
+}
+
+// SpanContext returns the SpanContext of the span.
+func (s *Span) SpanContext() SpanContext {
+	if s == nil {
+		return SpanContext{}
+	}
+	return s.internal.SpanContext()
+}
+
+// SetName sets the name of the span, if it is recording events.
+func (s *Span) SetName(name string) {
+	if !s.IsRecordingEvents() {
+		return
+	}
+	s.internal.SetName(name)
+}
+
+// SetStatus sets the status of the span, if it is recording events.
+func (s *Span) SetStatus(status Status) {
+	if !s.IsRecordingEvents() {
+		return
+	}
+	s.internal.SetStatus(status)
+}
+
+// AddAttributes sets attributes in the span.
+//
+// Existing attributes whose keys appear in the attributes parameter are overwritten.
+func (s *Span) AddAttributes(attributes ...Attribute) {
+	if !s.IsRecordingEvents() {
+		return
+	}
+	s.internal.AddAttributes(attributes...)
+}
+
+// Annotate adds an annotation with attributes.
+// Attributes can be nil.
+func (s *Span) Annotate(attributes []Attribute, str string) {
+	if !s.IsRecordingEvents() {
+		return
+	}
+	s.internal.Annotate(attributes, str)
+}
+
+// Annotatef adds an annotation with attributes.
+func (s *Span) Annotatef(attributes []Attribute, format string, a ...interface{}) {
+	if !s.IsRecordingEvents() {
+		return
+	}
+	s.internal.Annotatef(attributes, format, a...)
+}
+
+// AddMessageSendEvent adds a message send event to the span.
+//
+// messageID is an identifier for the message, which is recommended to be
+// unique in this span and the same between the send event and the receive
+// event (this allows to identify a message between the sender and receiver).
+// For example, this could be a sequence id.
+func (s *Span) AddMessageSendEvent(messageID, uncompressedByteSize, compressedByteSize int64) {
+	if !s.IsRecordingEvents() {
+		return
+	}
+	s.internal.AddMessageSendEvent(messageID, uncompressedByteSize, compressedByteSize)
+}
+
+// AddMessageReceiveEvent adds a message receive event to the span.
+//
+// messageID is an identifier for the message, which is recommended to be
+// unique in this span and the same between the send event and the receive
+// event (this allows to identify a message between the sender and receiver).
+// For example, this could be a sequence id.
+func (s *Span) AddMessageReceiveEvent(messageID, uncompressedByteSize, compressedByteSize int64) {
+	if !s.IsRecordingEvents() {
+		return
+	}
+	s.internal.AddMessageReceiveEvent(messageID, uncompressedByteSize, compressedByteSize)
+}
+
+// AddLink adds a link to the span.
+func (s *Span) AddLink(l Link) {
+	if !s.IsRecordingEvents() {
+		return
+	}
+	s.internal.AddLink(l)
+}
+
+// String prints a string representation of a span.
+func (s *Span) String() string {
+	if s == nil {
+		return "<nil>"
+	}
+	return s.internal.String()
+}