perf: optimize pprof split

pkg/distributor/distributor.go

@@ -820,7 +820,7 @@ func extractSampleSeries(
 ) {
 	for _, series := range req.Series {
 		for _, p := range series.Samples {
-			v := &sampleSeriesVisitor{profile: p.Profile.Profile}
+			v := &sampleSeriesVisitor{profile: p.Profile}
 			pprofsplit.VisitSampleSeries(
 				p.Profile.Profile,
 				series.Labels,
@@ -834,22 +834,28 @@ func extractSampleSeries(
 				CountDiscardedBytes(string(validation.DroppedByRelabelRules), int64(v.discardedBytes))
 		}
 	}
-
 	return result, bytesRelabelDropped, profilesRelabelDropped
 }
 
 type sampleSeriesVisitor struct {
-	profile *profilev1.Profile
+	profile *pprof.Profile
 	exp     *pprof.SampleExporter
 	series  []*distributormodel.ProfileSeries
 
 	discardedBytes    int
 	discardedProfiles int
 }
 
+func (v *sampleSeriesVisitor) VisitProfile(labels []*typesv1.LabelPair) {
+	v.series = append(v.series, &distributormodel.ProfileSeries{
+		Samples: []*distributormodel.ProfileSample{{Profile: v.profile}},
+		Labels:  labels,
+	})
+}
+
 func (v *sampleSeriesVisitor) VisitSampleSeries(labels []*typesv1.LabelPair, samples []*profilev1.Sample) {
 	if v.exp == nil {
-		v.exp = pprof.NewSampleExporter(v.profile)
+		v.exp = pprof.NewSampleExporter(v.profile.Profile)
 	}
 	v.series = append(v.series, &distributormodel.ProfileSeries{
 		Samples: []*distributormodel.ProfileSample{{Profile: exportSamples(v.exp, samples)}},

pkg/experiment/ingester/segment.go

@@ -453,9 +453,9 @@ func (s *segment) ingest(ctx context.Context, tenantID string, p *profilev1.Prof
 	rules := s.sw.limits.IngestionRelabelingRules(tenantID)
 	usage := s.sw.limits.DistributorUsageGroups(tenantID).GetUsageGroups(tenantID, labels)
 	appender := &sampleAppender{
-		id:       id,
-		head:     s.headForIngest(k),
-		exporter: pprofmodel.NewSampleExporter(p),
+		head:    s.headForIngest(k),
+		profile: p,
+		id:      id,
 	}
 	pprofsplit.VisitSampleSeries(p, labels, rules, appender)
 	size -= appender.discardedBytes
@@ -467,13 +467,21 @@ func (s *segment) ingest(ctx context.Context, tenantID string, p *profilev1.Prof
 type sampleAppender struct {
 	id       uuid.UUID
 	head     *memdb.Head
+	profile  *profilev1.Profile
 	exporter *pprofmodel.SampleExporter
 
 	discardedProfiles int
 	discardedBytes    int
 }
 
+func (v *sampleAppender) VisitProfile(labels []*typesv1.LabelPair) {
+	v.head.Ingest(v.profile, v.id, labels)
+}
+
 func (v *sampleAppender) VisitSampleSeries(labels []*typesv1.LabelPair, samples []*profilev1.Sample) {
+	if v.exporter == nil {
+		v.exporter = pprofmodel.NewSampleExporter(v.profile)
+	}
 	var n profilev1.Profile
 	v.exporter.ExportSamples(&n, samples)
 	v.head.Ingest(&n, v.id, labels)

pkg/model/pprof_split/pprof_split.go

@@ -11,6 +11,10 @@ import (
 )
 
 type SampleSeriesVisitor interface {
+	// VisitProfile is called when no sample labels are present in
+	// the profile, or if all the sample labels are identical.
+	// Provided labels are the series labels processed with relabeling rules.
+	VisitProfile([]*typesv1.LabelPair)
 	VisitSampleSeries([]*typesv1.LabelPair, []*profilev1.Sample)
 	Discarded(profiles, bytes int)
 }
@@ -44,7 +48,7 @@ func VisitSampleSeries(
 			}
 		}
 		if len(profile.Sample) > 0 {
-			visitor.VisitSampleSeries(builder.Labels(), profile.Sample)
+			visitor.VisitProfile(builder.Labels())
 		}
 		return
 	}