reporter: report Links

libpf/apm.go

@@ -8,3 +8,4 @@ type APMTraceID [16]byte
 type APMTransactionID = APMSpanID
 
 var InvalidAPMSpanID = APMSpanID{0, 0, 0, 0, 0, 0, 0, 0}
+var InvalidAPMTraceID = APMTraceID{0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0, 0}

reporter/internal/pdata/generate.go

@@ -61,13 +61,15 @@ func (p *Pdata) Generate(tree samples.TraceEventsTree,
 	mappingSet := make(orderedset.OrderedSet[libpf.FrameMapping], 64)
 	stackSet := make(orderedset.OrderedSet[stackInfo], 64)
 	locationSet := make(orderedset.OrderedSet[locationInfo], 64)
+	linkSet := make(orderedset.OrderedSet[linkInfo], 64)
 
 	// By specification, the first element should be empty.
 	stringSet.Add("")
 	funcSet.Add(funcInfo{})
 	mappingSet.Add(libpf.FrameMapping{})
 	stackSet.Add(stackInfo{})
 	locationSet.Add(locationInfo{})
+	linkSet.Add(linkInfo{})
 
 	dic.LinkTable().AppendEmpty()
 	dic.MappingTable().AppendEmpty()
@@ -103,7 +105,7 @@ func (p *Pdata) Generate(tree samples.TraceEventsTree,
 
 			prof := sp.Profiles().AppendEmpty()
 			if err := p.setProfile(dic, attrMgr,
-				stringSet, funcSet, mappingSet, stackSet, locationSet,
+				stringSet, funcSet, mappingSet, stackSet, locationSet, linkSet,
 				origin, toEvents.Events[origin], prof,
 				collectionStartTime, collectionEndTime); err != nil {
 				return profiles, err
@@ -143,6 +145,7 @@ func (p *Pdata) setProfile(
 	mappingSet orderedset.OrderedSet[libpf.FrameMapping],
 	stackSet orderedset.OrderedSet[stackInfo],
 	locationSet orderedset.OrderedSet[locationInfo],
+	linkSet orderedset.OrderedSet[linkInfo],
 	origin libpf.Origin,
 	events samples.SampleToEvents,
 	profile pprofile.Profile,
@@ -177,6 +180,21 @@ func (p *Pdata) setProfile(
 			sample.Values().Append(traceInfo.OffTimes...)
 		}
 
+		if sampleKey.SpanID != libpf.InvalidAPMSpanID &&
+			sampleKey.TraceID != libpf.InvalidAPMTraceID {
+			link, ok := linkSet.AddWithCheck(linkInfo{
+				traceID: sampleKey.TraceID,
+				spanID:  sampleKey.SpanID,
+			})
+			if !ok {
+				l := dic.LinkTable().AppendEmpty()
+				l.SetSpanID(pcommon.SpanID(sampleKey.SpanID))
+				l.SetTraceID(pcommon.TraceID(sampleKey.TraceID))
+
+			}
+			sample.SetLinkIndex(link)
+		}
+
 		locationIndices := make([]int32, 0, len(traceInfo.Frames))
 		// Walk every frame of the trace.
 		for _, uniqueFrame := range traceInfo.Frames {

reporter/internal/pdata/generate_test.go

@@ -593,7 +593,15 @@ func TestGenerate_NativeFrame(t *testing.T) {
 	}
 	events := map[libpf.Origin]samples.SampleToEvents{
 		support.TraceOriginSampling: {
-			{}: &samples.TraceEvents{
+			{
+				Hash:   libpf.NewTraceHash(0, 1),
+				Comm:   libpf.Intern("abc"),
+				TID:    42,
+				CPU:    73,
+				SpanID: libpf.APMSpanID{0x0, 0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7},
+				TraceID: libpf.APMTraceID{0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
+					0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27},
+			}: &samples.TraceEvents{
 				Frames: singleFrameNative(mappingFile, 0x1000, 0x1000, 0x2000, 0x100),
 				Timestamps: []uint64{
 					uint64(time.Unix(1010, 0).UnixNano()),
@@ -668,6 +676,50 @@ func TestGenerate_NativeFrame(t *testing.T) {
 	// since it's resolved by the backend. The function table should be empty.
 	assert.Equal(t, 1, dic.FunctionTable().Len(),
 		"Function table should be empty for native frames")
+
+	// Verify SpanID and TraceID are set via Link
+	linkIndex := sample.LinkIndex()
+	assert.Greater(t, linkIndex, int32(0), "Sample should have a link set (index > 0, since 0 is dummy)")
+	link := dic.LinkTable().At(int(linkIndex))
+	expectedSpanID := pcommon.SpanID{0x0, 0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7}
+	expectedTraceID := pcommon.TraceID{0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
+		0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27}
+	assert.Equal(t, expectedSpanID, link.SpanID())
+	assert.Equal(t, expectedTraceID, link.TraceID())
+
+	// Verify Comm, TID, and CPU are set in sample attributes
+	attributeIndices := sample.AttributeIndices().AsRaw()
+	assert.NotEmpty(t, attributeIndices, "Sample should have attributes")
+
+	attributeTable := dic.AttributeTable()
+	stringTable := dic.StringTable()
+
+	foundComm := false
+	foundTID := false
+	foundCPU := false
+
+	for _, attrIdx := range attributeIndices {
+		attr := attributeTable.At(int(attrIdx))
+		keyStrIdx := attr.KeyStrindex()
+		key := stringTable.At(int(keyStrIdx))
+
+		switch key {
+		case string(semconv.ThreadNameKey):
+			assert.Equal(t, "abc", attr.Value().Str())
+			foundComm = true
+		case string(semconv.ThreadIDKey):
+			assert.Equal(t, int64(42), attr.Value().Int())
+			foundTID = true
+		case string(semconv.CPULogicalNumberKey):
+			assert.Equal(t, int64(73), attr.Value().Int())
+			foundCPU = true
+		}
+	}
+
+	assert.True(t, foundComm, "Sample should have Comm attribute set")
+	assert.True(t, foundTID, "Sample should have TID attribute set")
+	assert.True(t, foundCPU, "Sample should have CPU attribute set")
+
 }
 
 func TestStackTableOrder(t *testing.T) {
@@ -761,7 +813,15 @@ func TestGenerate_Validate(t *testing.T) {
 	}
 	events := map[libpf.Origin]samples.SampleToEvents{
 		support.TraceOriginSampling: {
-			{}: &samples.TraceEvents{
+			{
+				Hash:   libpf.NewTraceHash(0, 1),
+				Comm:   libpf.Intern("abc"),
+				TID:    42,
+				CPU:    73,
+				SpanID: libpf.APMSpanID{0x0, 0x1, 0x2, 0x3, 0x4, 0x5, 0x6, 0x7},
+				TraceID: libpf.APMTraceID{0x10, 0x11, 0x12, 0x13, 0x14, 0x15, 0x16, 0x17,
+					0x20, 0x21, 0x22, 0x23, 0x24, 0x25, 0x26, 0x27},
+			}: &samples.TraceEvents{
 				Frames: singleFrameTrace(libpf.PythonFrame, mapping, 0x30,
 					funcName, filePath, 123),
 				Timestamps: []uint64{42},

reporter/internal/pdata/helper.go

@@ -35,3 +35,9 @@ func hashLocationIndices(locationIndices []int32) uint64 {
 	h.Write(pfunsafe.FromSlice(locationIndices))
 	return h.Sum64()
 }
+
+// linkInfo is a helper used to deduplicate Links.
+type linkInfo struct {
+	spanID  libpf.APMSpanID
+	traceID libpf.APMTraceID
+}

reporter/samples/samples.go

@@ -19,6 +19,8 @@ type TraceEventMeta struct {
 	Origin         libpf.Origin
 	OffTime        int64
 	PID, TID       libpf.PID
+	SpanID         libpf.APMSpanID
+	TraceID        libpf.APMTraceID
 }
 
 // TraceEvents holds known information about a trace.
@@ -78,4 +80,7 @@ type SampleKey struct {
 
 	TID int64
 	CPU int64
+
+	SpanID  libpf.APMSpanID
+	TraceID libpf.APMTraceID
 }