Instana tracer implementation

vendor/github.com/opentracing/basictracer-go/wire/carrier.go

@@ -0,0 +1,40 @@
+package wire
+
+// ProtobufCarrier is a DelegatingCarrier that uses protocol buffers as the
+// the underlying datastructure. The reason for implementing DelagatingCarrier
+// is to allow for end users to serialize the underlying protocol buffers using
+// jsonpb or any other serialization forms they want.
+type ProtobufCarrier TracerState
+
+// SetState set's the tracer state.
+func (p *ProtobufCarrier) SetState(traceID, spanID uint64, sampled bool) {
+	p.TraceId = traceID
+	p.SpanId = spanID
+	p.Sampled = sampled
+}
+
+// State returns the tracer state.
+func (p *ProtobufCarrier) State() (traceID, spanID uint64, sampled bool) {
+	traceID = p.TraceId
+	spanID = p.SpanId
+	sampled = p.Sampled
+	return traceID, spanID, sampled
+}
+
+// SetBaggageItem sets a baggage item.
+func (p *ProtobufCarrier) SetBaggageItem(key, value string) {
+	if p.BaggageItems == nil {
+		p.BaggageItems = map[string]string{key: value}
+		return
+	}
+
+	p.BaggageItems[key] = value
+}
+
+// GetBaggage iterates over each baggage item and executes the callback with
+// the key:value pair.
+func (p *ProtobufCarrier) GetBaggage(f func(k, v string)) {
+	for k, v := range p.BaggageItems {
+		f(k, v)
+	}
+}