Creating symbols table on the query stream response

pkg/distributor/query.go

@@ -283,6 +283,7 @@ func (d *Distributor) queryIngesterStream(ctx context.Context, replicationSet ri
 				return nil, validation.LimitError(dataBytesLimitErr.Error())
 			}
 
+			result.DesymbolizeLabels()
 			result.Chunkseries = append(result.Chunkseries, resp.Chunkseries...)
 		}
 		return result, nil

pkg/ingester/client/custom.go

@@ -3,7 +3,11 @@ package client
 import (
 	"encoding/binary"
 
+	writev2 "github.com/prometheus/prometheus/prompb/io/prometheus/write/v2"
+
 	"github.com/cortexproject/cortex/pkg/chunk/encoding"
+	"github.com/cortexproject/cortex/pkg/cortexpb"
+	"github.com/prometheus/prometheus/model/labels"
 )
 
 // ChunksCount returns the number of chunks in response.
@@ -45,3 +49,45 @@ func (m *QueryStreamResponse) SamplesCount() (count int) {
 	}
 	return
 }
+
+func (m *QueryStreamResponse) DesymbolizeLabels() {
+	if len(m.Symbols) == 0 {
+		return
+	}
+
+	b := labels.NewScratchBuilder(0)
+
+	for i, cs := range m.Chunkseries {
+		if len(cs.LabelsRefs) > 0 {
+			m.Chunkseries[i].Labels = cortexpb.FromLabelsToLabelAdapters(desymbolizeLabels(&b, cs.LabelsRefs, m.Symbols))
+		}
+		cs.LabelsRefs = cs.LabelsRefs[:0]
+		b.Reset()
+	}
+	m.Symbols = m.Symbols[:0]
+}
+
+func (m *QueryStreamResponse) SymbolizeLabels() {
+	if len(m.Symbols) > 0 {
+		return
+	}
+
+	st := writev2.NewSymbolTable()
+	for i, _ := range m.Chunkseries {
+		if len(m.Chunkseries[i].Labels) > 0 {
+			m.Chunkseries[i].LabelsRefs = st.SymbolizeLabels(cortexpb.FromLabelAdaptersToLabels(m.Chunkseries[i].Labels), m.Chunkseries[i].LabelsRefs)
+		}
+		m.Chunkseries[i].Labels = m.Chunkseries[i].Labels[:0]
+	}
+	m.Symbols = st.Symbols()
+}
+
+// desymbolizeLabels decodes label references, with given symbols to labels.
+func desymbolizeLabels(b *labels.ScratchBuilder, labelRefs []uint32, symbols []string) labels.Labels {
+	b.Reset()
+	for i := 0; i < len(labelRefs); i += 2 {
+		b.Add(symbols[labelRefs[i]], symbols[labelRefs[i+1]])
+	}
+	b.Sort()
+	return b.Labels()
+}

pkg/ingester/client/custom_test.go

@@ -1,6 +1,7 @@
 package client
 
 import (
+	github_com_cortexproject_cortex_pkg_cortexpb "github.com/cortexproject/cortex/pkg/cortexpb"
 	"testing"
 	"time"
 
@@ -11,6 +12,31 @@ import (
 	"github.com/cortexproject/cortex/pkg/util"
 )
 
+func TestSYmbolizeLabels(t *testing.T) {
+	chunkSeries := []TimeSeriesChunk{
+		{
+			Labels: []github_com_cortexproject_cortex_pkg_cortexpb.LabelAdapter{
+				{"N1", "V1"},
+				{"N1", "V2"},
+				{"N3", "V3"},
+			},
+			Chunks: []Chunk{{Encoding: int32(encoding.PrometheusXorChunk), Data: []byte("data1")}},
+		},
+		{
+			Labels: []github_com_cortexproject_cortex_pkg_cortexpb.LabelAdapter{
+				{"V1", "N3"},
+				{"N2", "V3"},
+				{"Final", "Final2"},
+			},
+			Chunks: []Chunk{{Encoding: int32(encoding.PrometheusXorChunk), Data: []byte("data1")}},
+		},
+	}
+
+	r := QueryStreamResponse{Chunkseries: chunkSeries}
+	r.SymbolizeLabels()
+	r.DesymbolizeLabels()
+}
+
 func TestSamplesCount(t *testing.T) {
 	floatChk := util.GenerateChunk(t, time.Second, model.Time(0), 100, encoding.PrometheusXorChunk)
 	histogramChk := util.GenerateChunk(t, time.Second, model.Time(0), 300, encoding.PrometheusHistogramChunk)