Fix Goutham's comments

Signed-off-by: Ganesh Vernekar <[email protected]>

Author: codesome

pkg/ingester/label_pairs.go

@@ -88,25 +88,3 @@ func (a labelPairs) equal(b labels.Labels) bool {
 	}
 	return true
 }
-
-func newLabelPairs(metric labels.Labels) []client.LabelPair {
-	lp := make([]client.LabelPair, 0, len(metric))
-	for _, m := range metric {
-		lp = append(lp, client.LabelPair{
-			Name:  []byte(m.Name),
-			Value: []byte(m.Value),
-		})
-	}
-	return lp
-}
-
-func newLabelPairsFromLabelAdapters(metric []client.LabelAdapter) []client.LabelPair {
-	lp := make([]client.LabelPair, 0, len(metric))
-	for _, m := range metric {
-		lp = append(lp, client.LabelPair{
-			Name:  []byte(m.Name),
-			Value: []byte(m.Value),
-		})
-	}
-	return lp
-}

pkg/ingester/series.go

@@ -10,7 +10,6 @@ import (
 	"github.com/prometheus/prometheus/pkg/value"
 
 	"github.com/cortexproject/cortex/pkg/chunk/encoding"
-	"github.com/cortexproject/cortex/pkg/ingester/client"
 	"github.com/cortexproject/cortex/pkg/prom1/storage/metric"
 )
 
@@ -51,11 +50,6 @@ func newMemorySeries(m labels.Labels) *memorySeries {
 	}
 }
 
-// helper to extract the not-necessarily-sorted type used elsewhere, without casting everywhere.
-func (s *memorySeries) labels() []client.LabelPair {
-	return newLabelPairs(s.metric)
-}
-
 // add adds a sample pair to the series, possibly creating a new chunk.
 // The caller must have locked the fingerprint of the series.
 func (s *memorySeries) add(v model.SamplePair) error {

pkg/ingester/user_state.go

@@ -231,7 +231,7 @@ func (u *userState) createSeriesWithFingerprint(fp model.Fingerprint, metric lab
 	if record != nil {
 		record.Labels = append(record.Labels, Labels{
 			Fingerprint: uint64(fp),
-			Labels:      newLabelPairsFromLabelAdapters(metric),
+			Labels:      metric,
 		})
 	}
 

pkg/ingester/wal.go

@@ -351,7 +351,7 @@ func (w *walWrapper) checkpointSeries(cp *wal.WAL, userID string, fp model.Finge
 	buf, err := proto.Marshal(&Series{
 		UserId:      userID,
 		Fingerprint: uint64(fp),
-		Labels:      series.labels(),
+		Labels:      client.FromLabelsToLabelAdapters(series.metric),
 		Chunks:      wireChunks,
 	})
 	if err != nil {
@@ -472,6 +472,11 @@ Loop:
 		if err := proto.Unmarshal(reader.Record(), s); err != nil {
 			return err
 		}
+		// The yoloString from the unmarshal of LabelAdapter gets corrupted
+		// when travelling through the channel. Hence making a copy of that.
+		// This extra alloc during the read path is fine as it's only 1 time
+		// and saves extra allocs during write path by having LabelAdapter.
+		s.Labels = copyLabelAdapters(s.Labels)
 
 		select {
 		case errFromChan = <-errChan:
@@ -502,6 +507,17 @@ Loop:
 	return nil
 }
 
+func copyLabelAdapters(las []client.LabelAdapter) []client.LabelAdapter {
+	for i := range las {
+		n, v := make([]byte, len(las[i].Name)), make([]byte, len(las[i].Value))
+		copy(n, las[i].Name)
+		copy(v, las[i].Value)
+		las[i].Name = string(n)
+		las[i].Value = string(v)
+	}
+	return las
+}
+
 func processCheckpointRecord(userStates *userStates, seriesPool *sync.Pool, stateCache map[string]*userState,
 	seriesCache map[string]map[uint64]*memorySeries, seriesChan <-chan *Series, errChan chan error) {
 	var la []client.LabelAdapter
@@ -580,7 +596,6 @@ func processWAL(name string, startSegment int, userStates *userStates, nWorkers
 	defer closer.Close()
 
 	var (
-		la          []client.LabelAdapter
 		errFromChan error
 		record      = &Record{}
 	)
@@ -605,15 +620,7 @@ Loop:
 				if ok {
 					continue
 				}
-
-				la = la[:0]
-				for _, l := range labels.Labels {
-					la = append(la, client.LabelAdapter{
-						Name:  string(l.Name),
-						Value: string(l.Value),
-					})
-				}
-				_, err := state.createSeriesWithFingerprint(model.Fingerprint(labels.Fingerprint), la, nil, true)
+				_, err := state.createSeriesWithFingerprint(model.Fingerprint(labels.Fingerprint), labels.Labels, nil, true)
 				if err != nil {
 					return err
 				}

pkg/ingester/wal.pb.go

@@ -15,7 +15,7 @@ message Record {
 
 message Labels {
   uint64 fingerprint = 1;
-  repeated cortex.LabelPair labels = 2 [(gogoproto.nullable) = false];
+  repeated cortex.LabelPair labels = 2 [(gogoproto.nullable) = false, (gogoproto.customtype) = "github.com/cortexproject/cortex/pkg/ingester/client.LabelAdapter"];
 }
 
 message Sample {
@@ -27,6 +27,6 @@ message Sample {
 message Series {
   string user_id = 1;
   uint64 fingerprint = 2;
-  repeated cortex.LabelPair labels = 3 [(gogoproto.nullable) = false];
+  repeated cortex.LabelPair labels = 3 [(gogoproto.nullable) = false, (gogoproto.customtype) = "github.com/cortexproject/cortex/pkg/ingester/client.LabelAdapter"];
   repeated cortex.Chunk chunks = 4 [(gogoproto.nullable) = false];
 }