From ab58cae33bcb83cf204af6c496ea4055407ddaad Mon Sep 17 00:00:00 2001
From: Gustavo Silva Paiva <guustavo.paiva@gmail.com>
Date: Mon, 7 Oct 2019 13:40:36 -0300
Subject: [PATCH] export Links in Jaeger exporter. (#173)

---
 exporter/trace/jaeger/jaeger.go      | 25 +++++++++++++------------
 exporter/trace/jaeger/jaeger_test.go | 21 +++++++++++++++++++++
 2 files changed, 34 insertions(+), 12 deletions(-)

diff --git a/exporter/trace/jaeger/jaeger.go b/exporter/trace/jaeger/jaeger.go
index 14a1f882c49..51ed9002a80 100644
--- a/exporter/trace/jaeger/jaeger.go
+++ b/exporter/trace/jaeger/jaeger.go
@@ -182,16 +182,18 @@ func spanDataToThrift(data *trace.SpanData) *gen.Span {
 			Fields:    fields,
 		})
 	}
-	//TODO: [rghetia] add links.
-	//
-	//var refs []*gen.SpanRef
-	//for _, link := range data.Links {
-	//	refs = append(refs, &gen.SpanRef{
-	//		TraceIdHigh: bytesToInt64(link.TraceID[0:8]),
-	//		TraceIdLow:  bytesToInt64(link.TraceID[8:16]),
-	//		SpanId:      bytesToInt64(link.SpanID[:]),
-	//	})
-	//}
+
+	var refs []*gen.SpanRef
+	for _, link := range data.Links {
+		refs = append(refs, &gen.SpanRef{
+			TraceIdHigh: int64(link.TraceID.High),
+			TraceIdLow:  int64(link.TraceID.Low),
+			SpanId:      int64(link.SpanID),
+			// TODO(paivagustavo): properly set the reference type when specs are defined
+			//  see https://github.com/open-telemetry/opentelemetry-specification/issues/65
+			RefType: gen.SpanRefType_CHILD_OF,
+		})
+	}
 
 	return &gen.Span{
 		TraceIdHigh:   int64(data.SpanContext.TraceID.High),
@@ -204,8 +206,7 @@ func spanDataToThrift(data *trace.SpanData) *gen.Span {
 		Duration:      data.EndTime.Sub(data.StartTime).Nanoseconds() / 1000,
 		Tags:          tags,
 		Logs:          logs,
-		// TODO: goes with Links.
-		// References:    refs,
+		References:    refs,
 	}
 }
 
diff --git a/exporter/trace/jaeger/jaeger_test.go b/exporter/trace/jaeger/jaeger_test.go
index 256041bfe3b..3e97a71ac23 100644
--- a/exporter/trace/jaeger/jaeger_test.go
+++ b/exporter/trace/jaeger/jaeger_test.go
@@ -19,6 +19,8 @@ import (
 	"testing"
 	"time"
 
+	apitrace "go.opentelemetry.io/api/trace"
+
 	"github.com/google/go-cmp/cmp"
 	"google.golang.org/grpc/codes"
 
@@ -34,6 +36,9 @@ func Test_spanDataToThrift(t *testing.T) {
 	traceID := core.TraceID{High: 0x0102030405060708, Low: 0x090a0b0c0d0e0f10}
 	spanID := uint64(0x0102030405060708)
 
+	linkTraceID := core.TraceID{High: 0x0102030405060709, Low: 0x090a0b0c0d0e0f11}
+	linkSpanID := uint64(0x0102030405060709)
+
 	keyValue := "value"
 	statusCodeValue := int64(2)
 	doubleValue := float64(123.456)
@@ -55,6 +60,14 @@ func Test_spanDataToThrift(t *testing.T) {
 				Name:      "/foo",
 				StartTime: now,
 				EndTime:   now,
+				Links: []apitrace.Link{
+					apitrace.Link{
+						SpanContext: core.SpanContext{
+							TraceID: linkTraceID,
+							SpanID:  linkSpanID,
+						},
+					},
+				},
 				Attributes: []core.KeyValue{
 					{
 						Key:   core.Key{Name: "key"},
@@ -82,6 +95,14 @@ func Test_spanDataToThrift(t *testing.T) {
 					{Key: "status.code", VType: gen.TagType_LONG, VLong: &statusCodeValue},
 					{Key: "status.message", VType: gen.TagType_STRING, VStr: &statusMessage},
 				},
+				References: []*gen.SpanRef{
+					&gen.SpanRef{
+						RefType:     gen.SpanRefType_CHILD_OF,
+						TraceIdLow:  int64(linkTraceID.Low),
+						TraceIdHigh: int64(linkTraceID.High),
+						SpanId:      int64(linkSpanID),
+					},
+				},
 				// TODO [rghetia]: check Logs when event is added.
 			},
 		},