Ensure we have at least one mapping in pprof

Author: cyriltovena

pkg/phlaredb/head_test.go

@@ -335,6 +335,7 @@ func TestHeadIngestRealProfiles(t *testing.T) {
 		"testdata/profile",
 		"testdata/profile_uncompressed",
 		"testdata/profile_python",
+		"testdata/profile_java",
 	}
 
 	head := newTestHead(t)

pkg/phlaredb/testdata/profile_java

@@ -189,9 +189,7 @@ func (s *sortedSample) Swap(i, j int) {
 	s.hashes[i], s.hashes[j] = s.hashes[j], s.hashes[i]
 }
 
-var (
-	currentTime = time.Now
-)
+var currentTime = time.Now
 
 // Normalize normalizes the profile by:
 //   - Removing all duplicate samples (summing their values).
@@ -207,6 +205,8 @@ func (p *Profile) Normalize() {
 		p.TimeNanos = currentTime().UnixNano()
 	}
 
+	p.ensureHasMapping()
+
 	// first we sort the samples location ids.
 	hashes := p.hasher.Hashes(p.Sample)
 
@@ -251,6 +251,29 @@ func (p *Profile) Normalize() {
 	p.clearSampleReferences(removedSamples)
 }
 
+// ensureHasMapping ensures all locations have at least a mapping.
+func (p *Profile) ensureHasMapping() {
+	var mId uint64
+	for _, m := range p.Mapping {
+		if mId < m.Id {
+			mId = m.Id
+		}
+	}
+	var fake *profilev1.Mapping
+	for _, l := range p.Location {
+		if l.MappingId == 0 {
+			if fake == nil {
+				fake = &profilev1.Mapping{
+					Id:          mId + 1,
+					MemoryLimit: ^uint64(0),
+				}
+				p.Mapping = append(p.Mapping, fake)
+			}
+			l.MappingId = fake.Id
+		}
+	}
+}
+
 func (p *Profile) clearSampleReferences(samples []*profilev1.Sample) {
 	if len(samples) == 0 {
 		return

pkg/pprof/pprof.go

@@ -68,10 +68,13 @@ func TestNormalizeProfile(t *testing.T) {
 		Sample: []*profilev1.Sample{
 			{LocationId: []uint64{2, 3}, Value: []int64{0, 1}, Label: []*profilev1.Label{}},
 		},
-		Mapping: []*profilev1.Mapping{},
+		Mapping: []*profilev1.Mapping{{
+			Id:          1,
+			MemoryLimit: ^uint64(0),
+		}},
 		Location: []*profilev1.Location{
-			{Id: 2, Line: []*profilev1.Line{{FunctionId: 2, Line: 1}, {FunctionId: 3, Line: 3}}},
-			{Id: 3, Line: []*profilev1.Line{{FunctionId: 3, Line: 1}, {FunctionId: 4, Line: 3}}},
+			{Id: 2, MappingId: 1, Line: []*profilev1.Line{{FunctionId: 2, Line: 1}, {FunctionId: 3, Line: 3}}},
+			{Id: 3, MappingId: 1, Line: []*profilev1.Line{{FunctionId: 3, Line: 1}, {FunctionId: 4, Line: 3}}},
 		},
 		Function: []*profilev1.Function{
 			{Id: 2, Name: 6, SystemName: 7, Filename: 8, StartLine: 1},
@@ -137,6 +140,19 @@ func TestRemoveDuplicateSampleStacktraces(t *testing.T) {
 	require.Equal(t, total-duplicate, len(p.Sample), "unexpected total samples")
 }
 
+func TestEmptyMappingJava(t *testing.T) {
+	p, err := OpenFile("testdata/profile_java")
+	require.NoError(t, err)
+	require.Len(t, p.Mapping, 0)
+
+	p.Normalize()
+	require.Len(t, p.Mapping, 1)
+
+	for _, loc := range p.Location {
+		require.Equal(t, loc.MappingId, uint64(1))
+	}
+}
+
 func countSampleDuplicates(p *Profile) int {
 	hashes := p.hasher.Hashes(p.Sample)
 	uniq := map[uint64][]*profilev1.Sample{}