[PRW 2.0] (part3) moved type specific conversions to prompb and writev2 codecs.

Signed-off-by: bwplotka <bwplotka@gmail.com>

prompb/codec.go

@@ -0,0 +1,198 @@
+// Copyright 2024 Prometheus Team
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package prompb
+
+import (
+	"strings"
+
+	"github.com/prometheus/common/model"
+
+	"github.com/prometheus/prometheus/model/exemplar"
+	"github.com/prometheus/prometheus/model/histogram"
+	"github.com/prometheus/prometheus/model/labels"
+)
+
+// NOTE(bwplotka): This file's code is tested in /prompb/rwcommon.
+
+// ToLabels return model labels.Labels from timeseries' remote labels.
+func (m TimeSeries) ToLabels(b *labels.ScratchBuilder, _ []string) labels.Labels {
+	return labelProtosToLabels(b, m.GetLabels())
+}
+
+// ToLabels return model labels.Labels from timeseries' remote labels.
+func (m ChunkedSeries) ToLabels(b *labels.ScratchBuilder, _ []string) labels.Labels {
+	return labelProtosToLabels(b, m.GetLabels())
+}
+
+func labelProtosToLabels(b *labels.ScratchBuilder, labelPairs []Label) labels.Labels {
+	b.Reset()
+	for _, l := range labelPairs {
+		b.Add(l.Name, l.Value)
+	}
+	b.Sort()
+	return b.Labels()
+}
+
+// FromLabels transforms labels into prompb labels. The buffer slice
+// will be used to avoid allocations if it is big enough to store the labels.
+func FromLabels(lbls labels.Labels, buf []Label) []Label {
+	result := buf[:0]
+	lbls.Range(func(l labels.Label) {
+		result = append(result, Label{
+			Name:  l.Name,
+			Value: l.Value,
+		})
+	})
+	return result
+}
+
+// FromMetadataType transforms a Prometheus metricType into prompb metricType. Since the former is a string we need to transform it to an enum.
+func FromMetadataType(t model.MetricType) MetricMetadata_MetricType {
+	mt := strings.ToUpper(string(t))
+	v, ok := MetricMetadata_MetricType_value[mt]
+	if !ok {
+		return MetricMetadata_UNKNOWN
+	}
+	return MetricMetadata_MetricType(v)
+}
+
+// IsFloatHistogram returns true if the histogram is float.
+func (h Histogram) IsFloatHistogram() bool {
+	_, ok := h.GetCount().(*Histogram_CountFloat)
+	return ok
+}
+
+// ToIntHistogram returns integer Prometheus histogram from the remote implementation
+// of integer histogram. It's a caller responsibility to check if it's not a float histogram.
+func (h Histogram) ToIntHistogram() *histogram.Histogram {
+	return &histogram.Histogram{
+		CounterResetHint: histogram.CounterResetHint(h.ResetHint),
+		Schema:           h.Schema,
+		ZeroThreshold:    h.ZeroThreshold,
+		ZeroCount:        h.GetZeroCountInt(),
+		Count:            h.GetCountInt(),
+		Sum:              h.Sum,
+		PositiveSpans:    spansProtoToSpans(h.GetPositiveSpans()),
+		PositiveBuckets:  h.GetPositiveDeltas(),
+		NegativeSpans:    spansProtoToSpans(h.GetNegativeSpans()),
+		NegativeBuckets:  h.GetNegativeDeltas(),
+	}
+}
+
+// ToFloatHistogram returns float Prometheus histogram from the remote implementation
+// of float histogram. If the underlying implementation is an integer histogram, a
+// conversion is performed.
+func (h Histogram) ToFloatHistogram() *histogram.FloatHistogram {
+	if h.IsFloatHistogram() {
+		return &histogram.FloatHistogram{
+			CounterResetHint: histogram.CounterResetHint(h.ResetHint),
+			Schema:           h.Schema,
+			ZeroThreshold:    h.ZeroThreshold,
+			ZeroCount:        h.GetZeroCountFloat(),
+			Count:            h.GetCountFloat(),
+			Sum:              h.Sum,
+			PositiveSpans:    spansProtoToSpans(h.GetPositiveSpans()),
+			PositiveBuckets:  h.GetPositiveCounts(),
+			NegativeSpans:    spansProtoToSpans(h.GetNegativeSpans()),
+			NegativeBuckets:  h.GetNegativeCounts(),
+		}
+	}
+	// Conversion from integer histogram.
+	return &histogram.FloatHistogram{
+		CounterResetHint: histogram.CounterResetHint(h.ResetHint),
+		Schema:           h.Schema,
+		ZeroThreshold:    h.ZeroThreshold,
+		ZeroCount:        float64(h.GetZeroCountInt()),
+		Count:            float64(h.GetCountInt()),
+		Sum:              h.Sum,
+		PositiveSpans:    spansProtoToSpans(h.GetPositiveSpans()),
+		PositiveBuckets:  deltasToCounts(h.GetPositiveDeltas()),
+		NegativeSpans:    spansProtoToSpans(h.GetNegativeSpans()),
+		NegativeBuckets:  deltasToCounts(h.GetNegativeDeltas()),
+	}
+}
+
+func spansProtoToSpans(s []BucketSpan) []histogram.Span {
+	spans := make([]histogram.Span, len(s))
+	for i := 0; i < len(s); i++ {
+		spans[i] = histogram.Span{Offset: s[i].Offset, Length: s[i].Length}
+	}
+
+	return spans
+}
+
+func deltasToCounts(deltas []int64) []float64 {
+	counts := make([]float64, len(deltas))
+	var cur float64
+	for i, d := range deltas {
+		cur += float64(d)
+		counts[i] = cur
+	}
+	return counts
+}
+
+// FromIntHistogram returns remote Histogram from the integer Histogram.
+func FromIntHistogram(timestamp int64, h *histogram.Histogram) Histogram {
+	return Histogram{
+		Count:          &Histogram_CountInt{CountInt: h.Count},
+		Sum:            h.Sum,
+		Schema:         h.Schema,
+		ZeroThreshold:  h.ZeroThreshold,
+		ZeroCount:      &Histogram_ZeroCountInt{ZeroCountInt: h.ZeroCount},
+		NegativeSpans:  spansToSpansProto(h.NegativeSpans),
+		NegativeDeltas: h.NegativeBuckets,
+		PositiveSpans:  spansToSpansProto(h.PositiveSpans),
+		PositiveDeltas: h.PositiveBuckets,
+		ResetHint:      Histogram_ResetHint(h.CounterResetHint),
+		Timestamp:      timestamp,
+	}
+}
+
+// FromFloatHistogram returns remote Histogram from the float Histogram.
+func FromFloatHistogram(timestamp int64, fh *histogram.FloatHistogram) Histogram {
+	return Histogram{
+		Count:          &Histogram_CountFloat{CountFloat: fh.Count},
+		Sum:            fh.Sum,
+		Schema:         fh.Schema,
+		ZeroThreshold:  fh.ZeroThreshold,
+		ZeroCount:      &Histogram_ZeroCountFloat{ZeroCountFloat: fh.ZeroCount},
+		NegativeSpans:  spansToSpansProto(fh.NegativeSpans),
+		NegativeCounts: fh.NegativeBuckets,
+		PositiveSpans:  spansToSpansProto(fh.PositiveSpans),
+		PositiveCounts: fh.PositiveBuckets,
+		ResetHint:      Histogram_ResetHint(fh.CounterResetHint),
+		Timestamp:      timestamp,
+	}
+}
+
+func spansToSpansProto(s []histogram.Span) []BucketSpan {
+	spans := make([]BucketSpan, len(s))
+	for i := 0; i < len(s); i++ {
+		spans[i] = BucketSpan{Offset: s[i].Offset, Length: s[i].Length}
+	}
+
+	return spans
+}
+
+// ToExemplar converts remote exemplar to model exemplar.
+func (m Exemplar) ToExemplar(b *labels.ScratchBuilder, _ []string) exemplar.Exemplar {
+	timestamp := m.Timestamp
+
+	return exemplar.Exemplar{
+		Labels: labelProtosToLabels(b, m.GetLabels()),
+		Value:  m.Value,
+		Ts:     timestamp,
+		HasTs:  timestamp != 0,
+	}
+}

prompb/custom.go

@@ -17,14 +17,6 @@ import (
 	"sync"
 )
 
-func (m Sample) T() int64   { return m.Timestamp }
-func (m Sample) V() float64 { return m.Value }
-
-func (h Histogram) IsFloatHistogram() bool {
-	_, ok := h.GetCount().(*Histogram_CountFloat)
-	return ok
-}
-
 func (r *ChunkedReadResponse) PooledMarshal(p *sync.Pool) ([]byte, error) {
 	size := r.Size()
 	data, ok := p.Get().(*[]byte)

prompb/io/prometheus/write/v2/codec.go

@@ -0,0 +1,183 @@
+// Copyright 2024 Prometheus Team
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package writev2
+
+import (
+	"strings"
+
+	"github.com/prometheus/common/model"
+
+	"github.com/prometheus/prometheus/prompb"
+
+	"github.com/prometheus/prometheus/model/exemplar"
+	"github.com/prometheus/prometheus/model/histogram"
+	"github.com/prometheus/prometheus/model/labels"
+	"github.com/prometheus/prometheus/model/metadata"
+)
+
+// NOTE(bwplotka): This file's code is tested in /prompb/rwcommon.
+
+// ToLabels return model labels.Labels from timeseries' remote labels.
+func (m TimeSeries) ToLabels(b *labels.ScratchBuilder, symbols []string) labels.Labels {
+	return desymbolizeLabels(b, m.GetLabelsRefs(), symbols)
+}
+
+// ToMetadata return model metadata from timeseries' remote metadata.
+func (m TimeSeries) ToMetadata(symbols []string) metadata.Metadata {
+	mt := strings.ToLower(m.Metadata.Type.String())
+	return metadata.Metadata{
+		Type: model.MetricType(mt), // TODO(@tpaschalis) a better way for this?
+		Unit: symbols[m.Metadata.UnitRef],
+		Help: symbols[m.Metadata.HelpRef],
+	}
+}
+
+// FromMetadataType transforms a Prometheus metricType into writev2 metricType. Since the former is a string we need to transform it to an enum.
+func FromMetadataType(t model.MetricType) Metadata_MetricType {
+	mt := strings.ToUpper(string(t))
+	v, ok := prompb.MetricMetadata_MetricType_value[mt]
+	if !ok {
+		return Metadata_METRIC_TYPE_UNSPECIFIED
+	}
+	return Metadata_MetricType(v)
+}
+
+// IsFloatHistogram returns true if the histogram is float.
+func (h Histogram) IsFloatHistogram() bool {
+	_, ok := h.GetCount().(*Histogram_CountFloat)
+	return ok
+}
+
+// ToIntHistogram returns integer Prometheus histogram from the remote implementation
+// of integer histogram. It's a caller responsibility to check if it's not a float histogram.
+func (h Histogram) ToIntHistogram() *histogram.Histogram {
+	return &histogram.Histogram{
+		CounterResetHint: histogram.CounterResetHint(h.ResetHint),
+		Schema:           h.Schema,
+		ZeroThreshold:    h.ZeroThreshold,
+		ZeroCount:        h.GetZeroCountInt(),
+		Count:            h.GetCountInt(),
+		Sum:              h.Sum,
+		PositiveSpans:    spansProtoToSpans(h.GetPositiveSpans()),
+		PositiveBuckets:  h.GetPositiveDeltas(),
+		NegativeSpans:    spansProtoToSpans(h.GetNegativeSpans()),
+		NegativeBuckets:  h.GetNegativeDeltas(),
+	}
+}
+
+// ToFloatHistogram returns float Prometheus histogram from the remote implementation
+// of float histogram. If the underlying implementation is an integer histogram, a
+// conversion is performed.
+func (h Histogram) ToFloatHistogram() *histogram.FloatHistogram {
+	if h.IsFloatHistogram() {
+		return &histogram.FloatHistogram{
+			CounterResetHint: histogram.CounterResetHint(h.ResetHint),
+			Schema:           h.Schema,
+			ZeroThreshold:    h.ZeroThreshold,
+			ZeroCount:        h.GetZeroCountFloat(),
+			Count:            h.GetCountFloat(),
+			Sum:              h.Sum,
+			PositiveSpans:    spansProtoToSpans(h.GetPositiveSpans()),
+			PositiveBuckets:  h.GetPositiveCounts(),
+			NegativeSpans:    spansProtoToSpans(h.GetNegativeSpans()),
+			NegativeBuckets:  h.GetNegativeCounts(),
+		}
+	}
+	// Conversion from integer histogram.
+	return &histogram.FloatHistogram{
+		CounterResetHint: histogram.CounterResetHint(h.ResetHint),
+		Schema:           h.Schema,
+		ZeroThreshold:    h.ZeroThreshold,
+		ZeroCount:        float64(h.GetZeroCountInt()),
+		Count:            float64(h.GetCountInt()),
+		Sum:              h.Sum,
+		PositiveSpans:    spansProtoToSpans(h.GetPositiveSpans()),
+		PositiveBuckets:  deltasToCounts(h.GetPositiveDeltas()),
+		NegativeSpans:    spansProtoToSpans(h.GetNegativeSpans()),
+		NegativeBuckets:  deltasToCounts(h.GetNegativeDeltas()),
+	}
+}
+
+func spansProtoToSpans(s []BucketSpan) []histogram.Span {
+	spans := make([]histogram.Span, len(s))
+	for i := 0; i < len(s); i++ {
+		spans[i] = histogram.Span{Offset: s[i].Offset, Length: s[i].Length}
+	}
+
+	return spans
+}
+
+func deltasToCounts(deltas []int64) []float64 {
+	counts := make([]float64, len(deltas))
+	var cur float64
+	for i, d := range deltas {
+		cur += float64(d)
+		counts[i] = cur
+	}
+	return counts
+}
+
+// FromIntHistogram returns remote Histogram from the integer Histogram.
+func FromIntHistogram(timestamp int64, h *histogram.Histogram) Histogram {
+	return Histogram{
+		Count:          &Histogram_CountInt{CountInt: h.Count},
+		Sum:            h.Sum,
+		Schema:         h.Schema,
+		ZeroThreshold:  h.ZeroThreshold,
+		ZeroCount:      &Histogram_ZeroCountInt{ZeroCountInt: h.ZeroCount},
+		NegativeSpans:  spansToSpansProto(h.NegativeSpans),
+		NegativeDeltas: h.NegativeBuckets,
+		PositiveSpans:  spansToSpansProto(h.PositiveSpans),
+		PositiveDeltas: h.PositiveBuckets,
+		ResetHint:      Histogram_ResetHint(h.CounterResetHint),
+		Timestamp:      timestamp,
+	}
+}
+
+// FromFloatHistogram returns remote Histogram from the float Histogram.
+func FromFloatHistogram(timestamp int64, fh *histogram.FloatHistogram) Histogram {
+	return Histogram{
+		Count:          &Histogram_CountFloat{CountFloat: fh.Count},
+		Sum:            fh.Sum,
+		Schema:         fh.Schema,
+		ZeroThreshold:  fh.ZeroThreshold,
+		ZeroCount:      &Histogram_ZeroCountFloat{ZeroCountFloat: fh.ZeroCount},
+		NegativeSpans:  spansToSpansProto(fh.NegativeSpans),
+		NegativeCounts: fh.NegativeBuckets,
+		PositiveSpans:  spansToSpansProto(fh.PositiveSpans),
+		PositiveCounts: fh.PositiveBuckets,
+		ResetHint:      Histogram_ResetHint(fh.CounterResetHint),
+		Timestamp:      timestamp,
+	}
+}
+
+func spansToSpansProto(s []histogram.Span) []BucketSpan {
+	spans := make([]BucketSpan, len(s))
+	for i := 0; i < len(s); i++ {
+		spans[i] = BucketSpan{Offset: s[i].Offset, Length: s[i].Length}
+	}
+
+	return spans
+}
+
+func (m Exemplar) ToExemplar(b *labels.ScratchBuilder, symbols []string) exemplar.Exemplar {
+	timestamp := m.Timestamp
+
+	return exemplar.Exemplar{
+		Labels: desymbolizeLabels(b, m.LabelsRefs, symbols),
+		Value:  m.Value,
+		Ts:     timestamp,
+		HasTs:  timestamp != 0,
+	}
+}

prompb/io/prometheus/write/v2/custom.go

@@ -20,11 +20,6 @@ import (
 func (m Sample) T() int64   { return m.Timestamp }
 func (m Sample) V() float64 { return m.Value }
 
-func (h Histogram) IsFloatHistogram() bool {
-	_, ok := h.GetCount().(*Histogram_CountFloat)
-	return ok
-}
-
 func (m *Request) OptimizedMarshal(dst []byte) ([]byte, error) {
 	siz := m.Size()
 	if cap(dst) < siz {

prompb/io/prometheus/write/v2/symbols.go

@@ -72,9 +72,9 @@ func (t *SymbolsTable) Reset() {
 	}
 }
 
-// DesymbolizeLabels decodes label references, with given symbols to labels.
+// desymbolizeLabels decodes label references, with given symbols to labels.
-func DesymbolizeLabels(labelRefs []uint32, symbols []string) labels.Labels {
+func desymbolizeLabels(b *labels.ScratchBuilder, labelRefs []uint32, symbols []string) labels.Labels {
-	b := labels.NewScratchBuilder(len(labelRefs))
+	b.Reset()
 	for i := 0; i < len(labelRefs); i += 2 {
 		b.Add(symbols[labelRefs[i]], symbols[labelRefs[i+1]])
 	}

prompb/io/prometheus/write/v2/symbols_test.go

@@ -49,7 +49,8 @@ func TestSymbolsTable(t *testing.T) {
 	ls := labels.FromStrings("__name__", "qwer", "zxcv", "1234")
 	encoded := s.SymbolizeLabels(ls, nil)
 	require.Equal(t, []uint32{1, 3, 4, 5}, encoded)
-	decoded := DesymbolizeLabels(encoded, s.Symbols())
+	b := labels.NewScratchBuilder(len(encoded))
+	decoded := desymbolizeLabels(&b, encoded, s.Symbols())
 	require.Equal(t, ls, decoded)
 
 	// Different buf.

prompb/rwcommon/codec_test.go

@@ -0,0 +1,230 @@
+// Copyright 2024 Prometheus Team
+// Licensed under the Apache License, Version 2.0 (the "License");
+// you may not use this file except in compliance with the License.
+// You may obtain a copy of the License at
+//
+// http://www.apache.org/licenses/LICENSE-2.0
+//
+// Unless required by applicable law or agreed to in writing, software
+// distributed under the License is distributed on an "AS IS" BASIS,
+// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
+// See the License for the specific language governing permissions and
+// limitations under the License.
+
+package rwcommon
+
+import (
+	"testing"
+
+	"github.com/prometheus/common/model"
+	"github.com/stretchr/testify/require"
+
+	"github.com/prometheus/prometheus/model/labels"
+
+	"github.com/prometheus/prometheus/model/histogram"
+
+	"github.com/prometheus/prometheus/prompb"
+	writev2 "github.com/prometheus/prometheus/prompb/io/prometheus/write/v2"
+)
+
+func TestToLabels(t *testing.T) {
+	expected := labels.FromStrings("__name__", "metric1", "foo", "bar")
+
+	t.Run("v1", func(t *testing.T) {
+		ts := prompb.TimeSeries{Labels: []prompb.Label{{Name: "__name__", Value: "metric1"}, {Name: "foo", Value: "bar"}}}
+		b := labels.NewScratchBuilder(2)
+		require.Equal(t, expected, ts.ToLabels(&b, nil))
+		require.Equal(t, ts.Labels, prompb.FromLabels(expected, nil))
+		require.Equal(t, ts.Labels, prompb.FromLabels(expected, ts.Labels))
+	})
+	t.Run("v2", func(t *testing.T) {
+		v2Symbols := []string{"", "__name__", "metric1", "foo", "bar"}
+		ts := writev2.TimeSeries{LabelsRefs: []uint32{1, 2, 3, 4}}
+		b := labels.NewScratchBuilder(2)
+		require.Equal(t, expected, ts.ToLabels(&b, v2Symbols))
+		// No need for FromLabels in our prod code as we use symbol table to do so.
+	})
+}
+
+func TestFromMetadataType(t *testing.T) {
+	for _, tc := range []struct {
+		desc       string
+		input      model.MetricType
+		expectedV1 prompb.MetricMetadata_MetricType
+		expectedV2 writev2.Metadata_MetricType
+	}{
+		{
+			desc:       "with a single-word metric",
+			input:      model.MetricTypeCounter,
+			expectedV1: prompb.MetricMetadata_COUNTER,
+			expectedV2: writev2.Metadata_METRIC_TYPE_COUNTER,
+		},
+		{
+			desc:       "with a two-word metric",
+			input:      model.MetricTypeStateset,
+			expectedV1: prompb.MetricMetadata_STATESET,
+			expectedV2: writev2.Metadata_METRIC_TYPE_STATESET,
+		},
+		{
+			desc:       "with an unknown metric",
+			input:      "not-known",
+			expectedV1: prompb.MetricMetadata_UNKNOWN,
+			expectedV2: writev2.Metadata_METRIC_TYPE_UNSPECIFIED,
+		},
+	} {
+		t.Run(tc.desc, func(t *testing.T) {
+			t.Run("v1", func(t *testing.T) {
+				require.Equal(t, tc.expectedV1, prompb.FromMetadataType(tc.input))
+			})
+			t.Run("v2", func(t *testing.T) {
+				require.Equal(t, tc.expectedV2, writev2.FromMetadataType(tc.input))
+			})
+		})
+	}
+}
+
+func TestToHistogram_Empty(t *testing.T) {
+	t.Run("v1", func(t *testing.T) {
+		require.NotNilf(t, prompb.Histogram{}.ToIntHistogram(), "")
+		require.NotNilf(t, prompb.Histogram{}.ToFloatHistogram(), "")
+	})
+	t.Run("v2", func(t *testing.T) {
+		require.NotNilf(t, writev2.Histogram{}.ToIntHistogram(), "")
+		require.NotNilf(t, writev2.Histogram{}.ToFloatHistogram(), "")
+	})
+}
+
+func testIntHistogram() histogram.Histogram {
+	return histogram.Histogram{
+		CounterResetHint: histogram.GaugeType,
+		Schema:           0,
+		Count:            19,
+		Sum:              2.7,
+		ZeroThreshold:    1e-128,
+		PositiveSpans: []histogram.Span{
+			{Offset: 0, Length: 4},
+			{Offset: 0, Length: 0},
+			{Offset: 0, Length: 3},
+		},
+		PositiveBuckets: []int64{1, 2, -2, 1, -1, 0, 0},
+		NegativeSpans: []histogram.Span{
+			{Offset: 0, Length: 5},
+			{Offset: 1, Length: 0},
+			{Offset: 0, Length: 1},
+		},
+		NegativeBuckets: []int64{1, 2, -2, 1, -1, 0},
+	}
+}
+
+func testFloatHistogram() histogram.FloatHistogram {
+	return histogram.FloatHistogram{
+		CounterResetHint: histogram.GaugeType,
+		Schema:           0,
+		Count:            19,
+		Sum:              2.7,
+		ZeroThreshold:    1e-128,
+		PositiveSpans: []histogram.Span{
+			{Offset: 0, Length: 4},
+			{Offset: 0, Length: 0},
+			{Offset: 0, Length: 3},
+		},
+		PositiveBuckets: []float64{1, 3, 1, 2, 1, 1, 1},
+		NegativeSpans: []histogram.Span{
+			{Offset: 0, Length: 5},
+			{Offset: 1, Length: 0},
+			{Offset: 0, Length: 1},
+		},
+		NegativeBuckets: []float64{1, 3, 1, 2, 1, 1},
+	}
+}
+
+func TestFromIntToFloatOrIntHistogram(t *testing.T) {
+	testIntHist := testIntHistogram()
+	testFloatHist := testFloatHistogram()
+
+	t.Run("v1", func(t *testing.T) {
+		h := prompb.FromIntHistogram(123, &testIntHist)
+		require.False(t, h.IsFloatHistogram())
+		require.Equal(t, int64(123), h.Timestamp)
+		require.Equal(t, &testIntHist, h.ToIntHistogram())
+		require.Equal(t, &testFloatHist, h.ToFloatHistogram())
+	})
+	t.Run("v2", func(t *testing.T) {
+		h := writev2.FromIntHistogram(123, &testIntHist)
+		require.False(t, h.IsFloatHistogram())
+		require.Equal(t, int64(123), h.Timestamp)
+		require.Equal(t, &testIntHist, h.ToIntHistogram())
+		require.Equal(t, &testFloatHist, h.ToFloatHistogram())
+	})
+}
+
+func TestFromFloatToFloatHistogram(t *testing.T) {
+	testFloatHist := testFloatHistogram()
+
+	t.Run("v1", func(t *testing.T) {
+		h := prompb.FromFloatHistogram(123, &testFloatHist)
+		require.True(t, h.IsFloatHistogram())
+		require.Equal(t, int64(123), h.Timestamp)
+		require.Equal(t, &testFloatHist, h.ToFloatHistogram())
+	})
+	t.Run("v2", func(t *testing.T) {
+		h := writev2.FromFloatHistogram(123, &testFloatHist)
+		require.True(t, h.IsFloatHistogram())
+		require.Equal(t, int64(123), h.Timestamp)
+		require.Equal(t, &testFloatHist, h.ToFloatHistogram())
+	})
+}
+
+func TestFromIntOrFloatHistogram_ResetHint(t *testing.T) {
+	for _, tc := range []struct {
+		input      histogram.CounterResetHint
+		expectedV1 prompb.Histogram_ResetHint
+		expectedV2 writev2.Histogram_ResetHint
+	}{
+		{
+			input:      histogram.UnknownCounterReset,
+			expectedV1: prompb.Histogram_UNKNOWN,
+			expectedV2: writev2.Histogram_RESET_HINT_UNSPECIFIED,
+		},
+		{
+			input:      histogram.CounterReset,
+			expectedV1: prompb.Histogram_YES,
+			expectedV2: writev2.Histogram_RESET_HINT_YES,
+		},
+		{
+			input:      histogram.NotCounterReset,
+			expectedV1: prompb.Histogram_NO,
+			expectedV2: writev2.Histogram_RESET_HINT_NO,
+		},
+		{
+			input:      histogram.GaugeType,
+			expectedV1: prompb.Histogram_GAUGE,
+			expectedV2: writev2.Histogram_RESET_HINT_GAUGE,
+		},
+	} {
+		t.Run("", func(t *testing.T) {
+			t.Run("v1", func(t *testing.T) {
+				h := testIntHistogram()
+				h.CounterResetHint = tc.input
+				got := prompb.FromIntHistogram(1337, &h)
+				require.Equal(t, tc.expectedV1, got.GetResetHint())
+
+				fh := testFloatHistogram()
+				fh.CounterResetHint = tc.input
+				got2 := prompb.FromFloatHistogram(1337, &fh)
+				require.Equal(t, tc.expectedV1, got2.GetResetHint())
+			})
+			t.Run("v2", func(t *testing.T) {
+				h := testIntHistogram()
+				h.CounterResetHint = tc.input
+				got := writev2.FromIntHistogram(1337, &h)
+				require.Equal(t, tc.expectedV2, got.GetResetHint())
+
+				fh := testFloatHistogram()
+				fh.CounterResetHint = tc.input
+				got2 := writev2.FromFloatHistogram(1337, &fh)
+				require.Equal(t, tc.expectedV2, got2.GetResetHint())
+			})
+		})
+	}
+}

storage/remote/codec.go

@@ -22,7 +22,6 @@ import (
 	"net/http"
 	"slices"
 	"sort"
-	"strings"
 	"sync"
 
 	"github.com/gogo/protobuf/proto"
@@ -30,10 +29,8 @@ import (
 	"github.com/prometheus/common/model"
 	"go.opentelemetry.io/collector/pdata/pmetric/pmetricotlp"
 
-	"github.com/prometheus/prometheus/model/exemplar"
 	"github.com/prometheus/prometheus/model/histogram"
 	"github.com/prometheus/prometheus/model/labels"
-	"github.com/prometheus/prometheus/model/metadata"
 	"github.com/prometheus/prometheus/prompb"
 	writev2 "github.com/prometheus/prometheus/prompb/io/prometheus/write/v2"
 	"github.com/prometheus/prometheus/storage"
@@ -155,10 +152,10 @@ func ToQueryResult(ss storage.SeriesSet, sampleLimit int) (*prompb.QueryResult,
 				})
 			case chunkenc.ValHistogram:
 				ts, h := iter.AtHistogram(nil)
-				histograms = append(histograms, HistogramToHistogramProto(ts, h))
+				histograms = append(histograms, prompb.FromIntHistogram(ts, h))
 			case chunkenc.ValFloatHistogram:
 				ts, fh := iter.AtFloatHistogram(nil)
-				histograms = append(histograms, FloatHistogramToHistogramProto(ts, fh))
+				histograms = append(histograms, prompb.FromFloatHistogram(ts, fh))
 			default:
 				return nil, ss.Warnings(), fmt.Errorf("unrecognized value type: %s", valType)
 			}
@@ -168,7 +165,7 @@ func ToQueryResult(ss storage.SeriesSet, sampleLimit int) (*prompb.QueryResult,
 		}
 
 		resp.Timeseries = append(resp.Timeseries, &prompb.TimeSeries{
-			Labels:     labelsToLabelsProto(series.Labels(), nil),
+			Labels:     prompb.FromLabels(series.Labels(), nil),
 			Samples:    samples,
 			Histograms: histograms,
 		})
@@ -184,7 +181,7 @@ func FromQueryResult(sortSeries bool, res *prompb.QueryResult) storage.SeriesSet
 		if err := validateLabelsAndMetricName(ts.Labels); err != nil {
 			return errSeriesSet{err: err}
 		}
-		lbls := labelProtosToLabels(&b, ts.Labels)
+		lbls := ts.ToLabels(&b, nil)
 		series = append(series, &concreteSeries{labels: lbls, floats: ts.Samples, histograms: ts.Histograms})
 	}
 
@@ -237,7 +234,7 @@ func StreamChunkedReadResponses(
 	for ss.Next() {
 		series := ss.At()
 		iter = series.Iterator(iter)
-		lbls = MergeLabels(labelsToLabelsProto(series.Labels(), lbls), sortedExternalLabels)
+		lbls = MergeLabels(prompb.FromLabels(series.Labels(), lbls), sortedExternalLabels)
 
 		maxDataLength := maxBytesInFrame
 		for _, lbl := range lbls {
@@ -483,21 +480,16 @@ func (c *concreteSeriesIterator) AtHistogram(*histogram.Histogram) (int64, *hist
 		panic("iterator is not on an integer histogram sample")
 	}
 	h := c.series.histograms[c.histogramsCur]
-	return h.Timestamp, HistogramProtoToHistogram(h)
+	return h.Timestamp, h.ToIntHistogram()
 }
 
 // AtFloatHistogram implements chunkenc.Iterator.
 func (c *concreteSeriesIterator) AtFloatHistogram(*histogram.FloatHistogram) (int64, *histogram.FloatHistogram) {
-	switch c.curValType {
+	if c.curValType == chunkenc.ValHistogram || c.curValType == chunkenc.ValFloatHistogram {
-	case chunkenc.ValHistogram:
 		fh := c.series.histograms[c.histogramsCur]
-		return fh.Timestamp, HistogramProtoToFloatHistogram(fh)
+		return fh.Timestamp, fh.ToFloatHistogram() // integer will be auto-converted.
-	case chunkenc.ValFloatHistogram:
-		fh := c.series.histograms[c.histogramsCur]
-		return fh.Timestamp, FloatHistogramProtoToFloatHistogram(fh)
-	default:
-		panic("iterator is not on a histogram sample")
 	}
+	panic("iterator is not on a histogram sample")
 }
 
 // AtT implements chunkenc.Iterator.
@@ -619,292 +611,6 @@ func FromLabelMatchers(matchers []*prompb.LabelMatcher) ([]*labels.Matcher, erro
 	return result, nil
 }
 
-func exemplarProtoToExemplar(b *labels.ScratchBuilder, ep prompb.Exemplar) exemplar.Exemplar {
-	timestamp := ep.Timestamp
-
-	return exemplar.Exemplar{
-		Labels: labelProtosToLabels(b, ep.Labels),
-		Value:  ep.Value,
-		Ts:     timestamp,
-		HasTs:  timestamp != 0,
-	}
-}
-
-func exemplarProtoV2ToExemplar(ep writev2.Exemplar, symbols []string) exemplar.Exemplar {
-	timestamp := ep.Timestamp
-
-	return exemplar.Exemplar{
-		Labels: writev2.DesymbolizeLabels(ep.LabelsRefs, symbols),
-		Value:  ep.Value,
-		Ts:     timestamp,
-		HasTs:  timestamp != 0,
-	}
-}
-
-func metadataProtoV2ToMetadata(mp writev2.Metadata, symbols []string) metadata.Metadata {
-	return metadata.Metadata{
-		Type: metricTypeFromProtoV2Equivalent(mp.Type),
-		Unit: symbols[mp.UnitRef],
-		Help: symbols[mp.HelpRef],
-	}
-}
-
-// HistogramProtoToHistogram extracts a (normal integer) Histogram from the
-// provided proto message. The caller has to make sure that the proto message
-// represents an integer histogram and not a float histogram, or it panics.
-func HistogramProtoToHistogram(hp prompb.Histogram) *histogram.Histogram {
-	if hp.IsFloatHistogram() {
-		panic("HistogramProtoToHistogram called with a float histogram")
-	}
-	return &histogram.Histogram{
-		CounterResetHint: histogram.CounterResetHint(hp.ResetHint),
-		Schema:           hp.Schema,
-		ZeroThreshold:    hp.ZeroThreshold,
-		ZeroCount:        hp.GetZeroCountInt(),
-		Count:            hp.GetCountInt(),
-		Sum:              hp.Sum,
-		PositiveSpans:    spansProtoToSpans(hp.GetPositiveSpans()),
-		PositiveBuckets:  hp.GetPositiveDeltas(),
-		NegativeSpans:    spansProtoToSpans(hp.GetNegativeSpans()),
-		NegativeBuckets:  hp.GetNegativeDeltas(),
-	}
-}
-
-// HistogramProtoV2ToHistogram extracts a (normal integer) Histogram from the
-// provided proto message. The caller has to make sure that the proto message
-// represents an integer histogram and not a float histogram, or it panics.
-func HistogramProtoV2ToHistogram(hp writev2.Histogram) *histogram.Histogram {
-	if hp.IsFloatHistogram() {
-		panic("HistogramProtoToHistogram called with a float histogram")
-	}
-	return &histogram.Histogram{
-		CounterResetHint: histogram.CounterResetHint(hp.ResetHint),
-		Schema:           hp.Schema,
-		ZeroThreshold:    hp.ZeroThreshold,
-		ZeroCount:        hp.GetZeroCountInt(),
-		Count:            hp.GetCountInt(),
-		Sum:              hp.Sum,
-		PositiveSpans:    spansProtoV2ToSpans(hp.GetPositiveSpans()),
-		PositiveBuckets:  hp.GetPositiveDeltas(),
-		NegativeSpans:    spansProtoV2ToSpans(hp.GetNegativeSpans()),
-		NegativeBuckets:  hp.GetNegativeDeltas(),
-	}
-}
-
-// FloatHistogramProtoToFloatHistogram extracts a float Histogram from the
-// provided proto message to a Float Histogram. The caller has to make sure that
-// the proto message represents a float histogram and not an integer histogram,
-// or it panics.
-func FloatHistogramProtoToFloatHistogram(hp prompb.Histogram) *histogram.FloatHistogram {
-	if !hp.IsFloatHistogram() {
-		panic("FloatHistogramProtoToFloatHistogram called with an integer histogram")
-	}
-	return &histogram.FloatHistogram{
-		CounterResetHint: histogram.CounterResetHint(hp.ResetHint),
-		Schema:           hp.Schema,
-		ZeroThreshold:    hp.ZeroThreshold,
-		ZeroCount:        hp.GetZeroCountFloat(),
-		Count:            hp.GetCountFloat(),
-		Sum:              hp.Sum,
-		PositiveSpans:    spansProtoToSpans(hp.GetPositiveSpans()),
-		PositiveBuckets:  hp.GetPositiveCounts(),
-		NegativeSpans:    spansProtoToSpans(hp.GetNegativeSpans()),
-		NegativeBuckets:  hp.GetNegativeCounts(),
-	}
-}
-
-// FloatHistogramProtoV2ToFloatHistogram extracts a float Histogram from the
-// provided proto message to a Float Histogram. The caller has to make sure that
-// the proto message represents a float histogram and not an integer histogram,
-// or it panics.
-func FloatHistogramProtoV2ToFloatHistogram(hp writev2.Histogram) *histogram.FloatHistogram {
-	if !hp.IsFloatHistogram() {
-		panic("FloatHistogramProtoToFloatHistogram called with an integer histogram")
-	}
-	return &histogram.FloatHistogram{
-		CounterResetHint: histogram.CounterResetHint(hp.ResetHint),
-		Schema:           hp.Schema,
-		ZeroThreshold:    hp.ZeroThreshold,
-		ZeroCount:        hp.GetZeroCountFloat(),
-		Count:            hp.GetCountFloat(),
-		Sum:              hp.Sum,
-		PositiveSpans:    spansProtoV2ToSpans(hp.GetPositiveSpans()),
-		PositiveBuckets:  hp.GetPositiveCounts(),
-		NegativeSpans:    spansProtoV2ToSpans(hp.GetNegativeSpans()),
-		NegativeBuckets:  hp.GetNegativeCounts(),
-	}
-}
-
-// HistogramProtoToFloatHistogram extracts and converts a (normal integer) histogram from the provided proto message
-// to a float histogram. The caller has to make sure that the proto message represents an integer histogram and not a
-// float histogram, or it panics.
-func HistogramProtoToFloatHistogram(hp prompb.Histogram) *histogram.FloatHistogram {
-	if hp.IsFloatHistogram() {
-		panic("HistogramProtoToFloatHistogram called with a float histogram")
-	}
-	return &histogram.FloatHistogram{
-		CounterResetHint: histogram.CounterResetHint(hp.ResetHint),
-		Schema:           hp.Schema,
-		ZeroThreshold:    hp.ZeroThreshold,
-		ZeroCount:        float64(hp.GetZeroCountInt()),
-		Count:            float64(hp.GetCountInt()),
-		Sum:              hp.Sum,
-		PositiveSpans:    spansProtoToSpans(hp.GetPositiveSpans()),
-		PositiveBuckets:  deltasToCounts(hp.GetPositiveDeltas()),
-		NegativeSpans:    spansProtoToSpans(hp.GetNegativeSpans()),
-		NegativeBuckets:  deltasToCounts(hp.GetNegativeDeltas()),
-	}
-}
-
-func FloatV2HistogramProtoToFloatHistogram(hp writev2.Histogram) *histogram.FloatHistogram {
-	if !hp.IsFloatHistogram() {
-		panic("FloatHistogramProtoToFloatHistogram called with an integer histogram")
-	}
-	return &histogram.FloatHistogram{
-		CounterResetHint: histogram.CounterResetHint(hp.ResetHint),
-		Schema:           hp.Schema,
-		ZeroThreshold:    hp.ZeroThreshold,
-		ZeroCount:        hp.GetZeroCountFloat(),
-		Count:            hp.GetCountFloat(),
-		Sum:              hp.Sum,
-		PositiveSpans:    spansProtoV2ToSpans(hp.GetPositiveSpans()),
-		PositiveBuckets:  hp.GetPositiveCounts(),
-		NegativeSpans:    spansProtoV2ToSpans(hp.GetNegativeSpans()),
-		NegativeBuckets:  hp.GetNegativeCounts(),
-	}
-}
-
-// V2HistogramProtoToHistogram extracts a (normal integer) Histogram from the
-// provided proto message. The caller has to make sure that the proto message
-// represents an integer histogram and not a float histogram, or it panics.
-func V2HistogramProtoToHistogram(hp writev2.Histogram) *histogram.Histogram {
-	if hp.IsFloatHistogram() {
-		panic("HistogramProtoToHistogram called with a float histogram")
-	}
-	return &histogram.Histogram{
-		CounterResetHint: histogram.CounterResetHint(hp.ResetHint),
-		Schema:           hp.Schema,
-		ZeroThreshold:    hp.ZeroThreshold,
-		ZeroCount:        hp.GetZeroCountInt(),
-		Count:            hp.GetCountInt(),
-		Sum:              hp.Sum,
-		PositiveSpans:    spansProtoV2ToSpans(hp.GetPositiveSpans()),
-		PositiveBuckets:  hp.GetPositiveDeltas(),
-		NegativeSpans:    spansProtoV2ToSpans(hp.GetNegativeSpans()),
-		NegativeBuckets:  hp.GetNegativeDeltas(),
-	}
-}
-
-func spansProtoToSpans(s []prompb.BucketSpan) []histogram.Span {
-	spans := make([]histogram.Span, len(s))
-	for i := 0; i < len(s); i++ {
-		spans[i] = histogram.Span{Offset: s[i].Offset, Length: s[i].Length}
-	}
-
-	return spans
-}
-
-func spansProtoV2ToSpans(s []writev2.BucketSpan) []histogram.Span {
-	spans := make([]histogram.Span, len(s))
-	for i := 0; i < len(s); i++ {
-		spans[i] = histogram.Span{Offset: s[i].Offset, Length: s[i].Length}
-	}
-
-	return spans
-}
-
-func deltasToCounts(deltas []int64) []float64 {
-	counts := make([]float64, len(deltas))
-	var cur float64
-	for i, d := range deltas {
-		cur += float64(d)
-		counts[i] = cur
-	}
-	return counts
-}
-
-func HistogramToHistogramProto(timestamp int64, h *histogram.Histogram) prompb.Histogram {
-	return prompb.Histogram{
-		Count:          &prompb.Histogram_CountInt{CountInt: h.Count},
-		Sum:            h.Sum,
-		Schema:         h.Schema,
-		ZeroThreshold:  h.ZeroThreshold,
-		ZeroCount:      &prompb.Histogram_ZeroCountInt{ZeroCountInt: h.ZeroCount},
-		NegativeSpans:  spansToSpansProto(h.NegativeSpans),
-		NegativeDeltas: h.NegativeBuckets,
-		PositiveSpans:  spansToSpansProto(h.PositiveSpans),
-		PositiveDeltas: h.PositiveBuckets,
-		ResetHint:      prompb.Histogram_ResetHint(h.CounterResetHint),
-		Timestamp:      timestamp,
-	}
-}
-
-func HistogramToV2HistogramProto(timestamp int64, h *histogram.Histogram) writev2.Histogram {
-	return writev2.Histogram{
-		Count:          &writev2.Histogram_CountInt{CountInt: h.Count},
-		Sum:            h.Sum,
-		Schema:         h.Schema,
-		ZeroThreshold:  h.ZeroThreshold,
-		ZeroCount:      &writev2.Histogram_ZeroCountInt{ZeroCountInt: h.ZeroCount},
-		NegativeSpans:  spansToV2SpansProto(h.NegativeSpans),
-		NegativeDeltas: h.NegativeBuckets,
-		PositiveSpans:  spansToV2SpansProto(h.PositiveSpans),
-		PositiveDeltas: h.PositiveBuckets,
-		ResetHint:      writev2.Histogram_ResetHint(h.CounterResetHint),
-		Timestamp:      timestamp,
-	}
-}
-
-func FloatHistogramToHistogramProto(timestamp int64, fh *histogram.FloatHistogram) prompb.Histogram {
-	return prompb.Histogram{
-		Count:          &prompb.Histogram_CountFloat{CountFloat: fh.Count},
-		Sum:            fh.Sum,
-		Schema:         fh.Schema,
-		ZeroThreshold:  fh.ZeroThreshold,
-		ZeroCount:      &prompb.Histogram_ZeroCountFloat{ZeroCountFloat: fh.ZeroCount},
-		NegativeSpans:  spansToSpansProto(fh.NegativeSpans),
-		NegativeCounts: fh.NegativeBuckets,
-		PositiveSpans:  spansToSpansProto(fh.PositiveSpans),
-		PositiveCounts: fh.PositiveBuckets,
-		ResetHint:      prompb.Histogram_ResetHint(fh.CounterResetHint),
-		Timestamp:      timestamp,
-	}
-}
-
-func FloatHistogramToV2HistogramProto(timestamp int64, fh *histogram.FloatHistogram) writev2.Histogram {
-	return writev2.Histogram{
-		Count:          &writev2.Histogram_CountFloat{CountFloat: fh.Count},
-		Sum:            fh.Sum,
-		Schema:         fh.Schema,
-		ZeroThreshold:  fh.ZeroThreshold,
-		ZeroCount:      &writev2.Histogram_ZeroCountFloat{ZeroCountFloat: fh.ZeroCount},
-		NegativeSpans:  spansToV2SpansProto(fh.NegativeSpans),
-		NegativeCounts: fh.NegativeBuckets,
-		PositiveSpans:  spansToV2SpansProto(fh.PositiveSpans),
-		PositiveCounts: fh.PositiveBuckets,
-		ResetHint:      writev2.Histogram_ResetHint(fh.CounterResetHint),
-		Timestamp:      timestamp,
-	}
-}
-
-func spansToSpansProto(s []histogram.Span) []prompb.BucketSpan {
-	spans := make([]prompb.BucketSpan, len(s))
-	for i := 0; i < len(s); i++ {
-		spans[i] = prompb.BucketSpan{Offset: s[i].Offset, Length: s[i].Length}
-	}
-
-	return spans
-}
-
-func spansToV2SpansProto(s []histogram.Span) []writev2.BucketSpan {
-	spans := make([]writev2.BucketSpan, len(s))
-	for i := 0; i < len(s); i++ {
-		spans[i] = writev2.BucketSpan{Offset: s[i].Offset, Length: s[i].Length}
-	}
-
-	return spans
-}
-
 // LabelProtosToMetric unpack a []*prompb.Label to a model.Metric.
 func LabelProtosToMetric(labelPairs []*prompb.Label) model.Metric {
 	metric := make(model.Metric, len(labelPairs))
@@ -914,55 +620,6 @@ func LabelProtosToMetric(labelPairs []*prompb.Label) model.Metric {
 	return metric
 }
 
-func labelProtosToLabels(b *labels.ScratchBuilder, labelPairs []prompb.Label) labels.Labels {
-	b.Reset()
-	for _, l := range labelPairs {
-		b.Add(l.Name, l.Value)
-	}
-	b.Sort()
-	return b.Labels()
-}
-
-// labelsToLabelsProto transforms labels into prompb labels. The buffer slice
-// will be used to avoid allocations if it is big enough to store the labels.
-func labelsToLabelsProto(lbls labels.Labels, buf []prompb.Label) []prompb.Label {
-	result := buf[:0]
-	lbls.Range(func(l labels.Label) {
-		result = append(result, prompb.Label{
-			Name:  l.Name,
-			Value: l.Value,
-		})
-	})
-	return result
-}
-
-// metricTypeToMetricTypeProto transforms a Prometheus metricType into prompb metricType. Since the former is a string we need to transform it to an enum.
-func metricTypeToMetricTypeProto(t model.MetricType) prompb.MetricMetadata_MetricType {
-	mt := strings.ToUpper(string(t))
-	v, ok := prompb.MetricMetadata_MetricType_value[mt]
-	if !ok {
-		return prompb.MetricMetadata_UNKNOWN
-	}
-
-	return prompb.MetricMetadata_MetricType(v)
-}
-
-// metricTypeToMetricTypeProtoV2 transforms a Prometheus metricType into writev2 metricType. Since the former is a string we need to transform it to an enum.
-func metricTypeToMetricTypeProtoV2(t model.MetricType) writev2.Metadata_MetricType {
-	mt := strings.ToUpper(string(t))
-	v, ok := prompb.MetricMetadata_MetricType_value[mt]
-	if !ok {
-		return writev2.Metadata_METRIC_TYPE_UNSPECIFIED
-	}
-
-	return writev2.Metadata_MetricType(v)
-}
-
-func metricTypeFromProtoV2Equivalent(t writev2.Metadata_MetricType) model.MetricType {
-	mt := strings.ToLower(t.String())
-	return model.MetricType(mt) // TODO(@tpaschalis) a better way for this?
-}
-
 // DecodeWriteRequest from an io.Reader into a prompb.WriteRequest, handling
 // snappy decompression.
 func DecodeWriteRequest(r io.Reader) (*prompb.WriteRequest, error) {
@@ -1055,74 +712,3 @@ func DecodeV2WriteRequestStr(r io.Reader) (*writev2.Request, error) {
 
 	return &req, nil
 }
-
-func V2WriteRequestToWriteRequest(redReq *writev2.Request) (*prompb.WriteRequest, error) {
-	req := &prompb.WriteRequest{
-		Timeseries: make([]prompb.TimeSeries, len(redReq.Timeseries)),
-		// TODO handle metadata?
-	}
-
-	for i, rts := range redReq.Timeseries {
-		writev2.DesymbolizeLabels(rts.LabelsRefs, redReq.Symbols).Range(func(l labels.Label) {
-			req.Timeseries[i].Labels = append(req.Timeseries[i].Labels, prompb.Label{
-				Name:  l.Name,
-				Value: l.Value,
-			})
-		})
-
-		exemplars := make([]prompb.Exemplar, len(rts.Exemplars))
-		for j, e := range rts.Exemplars {
-			exemplars[j].Value = e.Value
-			exemplars[j].Timestamp = e.Timestamp
-			writev2.DesymbolizeLabels(e.LabelsRefs, redReq.Symbols).Range(func(l labels.Label) {
-				exemplars[j].Labels = append(exemplars[j].Labels, prompb.Label{
-					Name:  l.Name,
-					Value: l.Value,
-				})
-			})
-		}
-		req.Timeseries[i].Exemplars = exemplars
-
-		req.Timeseries[i].Samples = make([]prompb.Sample, len(rts.Samples))
-		for j, s := range rts.Samples {
-			req.Timeseries[i].Samples[j].Timestamp = s.Timestamp
-			req.Timeseries[i].Samples[j].Value = s.Value
-		}
-
-		req.Timeseries[i].Histograms = make([]prompb.Histogram, len(rts.Histograms))
-		for j, h := range rts.Histograms {
-			// TODO: double check
-			if h.IsFloatHistogram() {
-				req.Timeseries[i].Histograms[j].Count = &prompb.Histogram_CountFloat{CountFloat: h.GetCountFloat()}
-				req.Timeseries[i].Histograms[j].ZeroCount = &prompb.Histogram_ZeroCountFloat{ZeroCountFloat: h.GetZeroCountFloat()}
-			} else {
-				req.Timeseries[i].Histograms[j].Count = &prompb.Histogram_CountInt{CountInt: h.GetCountInt()}
-				req.Timeseries[i].Histograms[j].ZeroCount = &prompb.Histogram_ZeroCountInt{ZeroCountInt: h.GetZeroCountInt()}
-			}
-
-			for _, span := range h.NegativeSpans {
-				req.Timeseries[i].Histograms[j].NegativeSpans = append(req.Timeseries[i].Histograms[j].NegativeSpans, prompb.BucketSpan{
-					Offset: span.Offset,
-					Length: span.Length,
-				})
-			}
-			for _, span := range h.PositiveSpans {
-				req.Timeseries[i].Histograms[j].PositiveSpans = append(req.Timeseries[i].Histograms[j].PositiveSpans, prompb.BucketSpan{
-					Offset: span.Offset,
-					Length: span.Length,
-				})
-			}
-
-			req.Timeseries[i].Histograms[j].Sum = h.Sum
-			req.Timeseries[i].Histograms[j].Schema = h.Schema
-			req.Timeseries[i].Histograms[j].ZeroThreshold = h.ZeroThreshold
-			req.Timeseries[i].Histograms[j].NegativeDeltas = h.NegativeDeltas
-			req.Timeseries[i].Histograms[j].NegativeCounts = h.NegativeCounts
-			req.Timeseries[i].Histograms[j].PositiveDeltas = h.PositiveDeltas
-			req.Timeseries[i].Histograms[j].PositiveCounts = h.PositiveCounts
-			req.Timeseries[i].Histograms[j].ResetHint = prompb.Histogram_ResetHint(h.ResetHint)
-			req.Timeseries[i].Histograms[j].Timestamp = h.Timestamp
-		}
-	}
-	return req, nil
-}

storage/remote/codec_test.go

@@ -21,7 +21,6 @@ import (
 
 	"github.com/go-kit/log"
 	"github.com/gogo/protobuf/proto"
-	"github.com/prometheus/common/model"
 	"github.com/stretchr/testify/require"
 
 	"github.com/prometheus/prometheus/model/histogram"
@@ -59,7 +58,7 @@ var writeRequestFixture = &prompb.WriteRequest{
 			},
 			Samples:    []prompb.Sample{{Value: 1, Timestamp: 0}},
 			Exemplars:  []prompb.Exemplar{{Labels: []prompb.Label{{Name: "f", Value: "g"}}, Value: 1, Timestamp: 0}},
-			Histograms: []prompb.Histogram{HistogramToHistogramProto(0, &testHistogram), FloatHistogramToHistogramProto(1, testHistogram.ToFloat(nil))},
+			Histograms: []prompb.Histogram{prompb.FromIntHistogram(0, &testHistogram), prompb.FromFloatHistogram(1, testHistogram.ToFloat(nil))},
 		},
 		{
 			Labels: []prompb.Label{
@@ -71,7 +70,7 @@ var writeRequestFixture = &prompb.WriteRequest{
 			},
 			Samples:    []prompb.Sample{{Value: 2, Timestamp: 1}},
 			Exemplars:  []prompb.Exemplar{{Labels: []prompb.Label{{Name: "h", Value: "i"}}, Value: 2, Timestamp: 1}},
-			Histograms: []prompb.Histogram{HistogramToHistogramProto(2, &testHistogram), FloatHistogramToHistogramProto(3, testHistogram.ToFloat(nil))},
+			Histograms: []prompb.Histogram{prompb.FromIntHistogram(2, &testHistogram), prompb.FromFloatHistogram(3, testHistogram.ToFloat(nil))},
 		},
 	},
 }
@@ -79,37 +78,23 @@ var writeRequestFixture = &prompb.WriteRequest{
 // writeV2RequestFixture represents the same request as writeRequestFixture, but using the v2 representation.
 var writeV2RequestFixture = func() *writev2.Request {
 	st := writev2.NewSymbolTable()
-	var labels []uint32
+	b := labels.NewScratchBuilder(0)
-	for _, s := range []string{
+	labelRefs := st.SymbolizeLabels(writeRequestFixture.Timeseries[0].ToLabels(&b, nil), nil)
-		"__name__", "test_metric1",
+	exemplar1LabelRefs := st.SymbolizeLabels(writeRequestFixture.Timeseries[0].Exemplars[0].ToExemplar(&b, nil).Labels, nil)
-		"b", "c",
+	exemplar2LabelRefs := st.SymbolizeLabels(writeRequestFixture.Timeseries[0].Exemplars[0].ToExemplar(&b, nil).Labels, nil)
-		"baz", "qux",
-		"d", "e",
-		"foo", "bar",
-	} {
-		ref := st.Symbolize(s)
-		labels = append(labels, ref)
-	}
-	for _, s := range []string{
-		"f", "g", // 10, 11
-		"h", "i", // 12, 13
-	} {
-		_ = st.Symbolize(s)
-	}
-
 	return &writev2.Request{
 		Timeseries: []writev2.TimeSeries{
 			{
-				LabelsRefs: labels,
+				LabelsRefs: labelRefs,
 				Samples:    []writev2.Sample{{Value: 1, Timestamp: 0}},
-				Exemplars:  []writev2.Exemplar{{LabelsRefs: []uint32{10, 11}, Value: 1, Timestamp: 0}},
+				Exemplars:  []writev2.Exemplar{{LabelsRefs: exemplar1LabelRefs, Value: 1, Timestamp: 0}},
-				Histograms: []writev2.Histogram{HistogramToV2HistogramProto(0, &testHistogram), FloatHistogramToV2HistogramProto(1, testHistogram.ToFloat(nil))},
+				Histograms: []writev2.Histogram{writev2.FromIntHistogram(0, &testHistogram), writev2.FromFloatHistogram(1, testHistogram.ToFloat(nil))},
 			},
 			{
-				LabelsRefs: labels,
+				LabelsRefs: labelRefs,
 				Samples:    []writev2.Sample{{Value: 2, Timestamp: 1}},
-				Exemplars:  []writev2.Exemplar{{LabelsRefs: []uint32{12, 13}, Value: 2, Timestamp: 1}},
+				Exemplars:  []writev2.Exemplar{{LabelsRefs: exemplar2LabelRefs, Value: 2, Timestamp: 1}},
-				Histograms: []writev2.Histogram{HistogramToV2HistogramProto(2, &testHistogram), FloatHistogramToV2HistogramProto(3, testHistogram.ToFloat(nil))},
+				Histograms: []writev2.Histogram{writev2.FromIntHistogram(2, &testHistogram), writev2.FromFloatHistogram(3, testHistogram.ToFloat(nil))},
 			},
 		},
 		Symbols: st.Symbols(),
@@ -310,7 +295,7 @@ func TestConcreteSeriesIterator_HistogramSamples(t *testing.T) {
 		} else {
 			ts = int64(i)
 		}
-		histProtos[i] = HistogramToHistogramProto(ts, h)
+		histProtos[i] = prompb.FromIntHistogram(ts, h)
 	}
 	series := &concreteSeries{
 		labels:     labels.FromStrings("foo", "bar"),
@@ -361,9 +346,9 @@ func TestConcreteSeriesIterator_FloatAndHistogramSamples(t *testing.T) {
 	histProtos := make([]prompb.Histogram, len(histograms))
 	for i, h := range histograms {
 		if i < 10 {
-			histProtos[i] = HistogramToHistogramProto(int64(i+1), h)
+			histProtos[i] = prompb.FromIntHistogram(int64(i+1), h)
 		} else {
-			histProtos[i] = HistogramToHistogramProto(int64(i+6), h)
+			histProtos[i] = prompb.FromIntHistogram(int64(i+6), h)
 		}
 	}
 	series := &concreteSeries{
@@ -443,7 +428,7 @@ func TestConcreteSeriesIterator_FloatAndHistogramSamples(t *testing.T) {
 	require.Equal(t, chunkenc.ValHistogram, it.Next())
 	ts, fh = it.AtFloatHistogram(nil)
 	require.Equal(t, int64(17), ts)
-	expected := HistogramProtoToFloatHistogram(HistogramToHistogramProto(int64(17), histograms[11]))
+	expected := prompb.FromIntHistogram(int64(17), histograms[11]).ToFloatHistogram()
 	require.Equal(t, expected, fh)
 
 	// Keep calling Next() until the end.
@@ -527,37 +512,6 @@ func TestMergeLabels(t *testing.T) {
 	}
 }
 
-func TestMetricTypeToMetricTypeProto(t *testing.T) {
-	tc := []struct {
-		desc     string
-		input    model.MetricType
-		expected prompb.MetricMetadata_MetricType
-	}{
-		{
-			desc:     "with a single-word metric",
-			input:    model.MetricTypeCounter,
-			expected: prompb.MetricMetadata_COUNTER,
-		},
-		{
-			desc:     "with a two-word metric",
-			input:    model.MetricTypeStateset,
-			expected: prompb.MetricMetadata_STATESET,
-		},
-		{
-			desc:     "with an unknown metric",
-			input:    "not-known",
-			expected: prompb.MetricMetadata_UNKNOWN,
-		},
-	}
-
-	for _, tt := range tc {
-		t.Run(tt.desc, func(t *testing.T) {
-			m := metricTypeToMetricTypeProto(tt.input)
-			require.Equal(t, tt.expected, m)
-		})
-	}
-}
-
 func TestDecodeWriteRequest(t *testing.T) {
 	buf, _, _, err := buildWriteRequest(nil, writeRequestFixture.Timeseries, nil, nil, nil, nil, "snappy")
 	require.NoError(t, err)
@@ -576,212 +530,9 @@ func TestDecodeV2WriteRequest(t *testing.T) {
 	require.Equal(t, writeV2RequestFixture, actual)
 }
 
-func TestNilHistogramProto(t *testing.T) {
-	// This function will panic if it impromperly handles nil
-	// values, causing the test to fail.
-	HistogramProtoToHistogram(prompb.Histogram{})
-	HistogramProtoToFloatHistogram(prompb.Histogram{})
-}
-
-func exampleHistogram() histogram.Histogram {
-	return histogram.Histogram{
-		CounterResetHint: histogram.GaugeType,
-		Schema:           0,
-		Count:            19,
-		Sum:              2.7,
-		PositiveSpans: []histogram.Span{
-			{Offset: 0, Length: 4},
-			{Offset: 0, Length: 0},
-			{Offset: 0, Length: 3},
-		},
-		PositiveBuckets: []int64{1, 2, -2, 1, -1, 0, 0},
-		NegativeSpans: []histogram.Span{
-			{Offset: 0, Length: 5},
-			{Offset: 1, Length: 0},
-			{Offset: 0, Length: 1},
-		},
-		NegativeBuckets: []int64{1, 2, -2, 1, -1, 0},
-	}
-}
-
-func exampleHistogramProto() prompb.Histogram {
-	return prompb.Histogram{
-		Count:         &prompb.Histogram_CountInt{CountInt: 19},
-		Sum:           2.7,
-		Schema:        0,
-		ZeroThreshold: 0,
-		ZeroCount:     &prompb.Histogram_ZeroCountInt{ZeroCountInt: 0},
-		NegativeSpans: []prompb.BucketSpan{
-			{
-				Offset: 0,
-				Length: 5,
-			},
-			{
-				Offset: 1,
-				Length: 0,
-			},
-			{
-				Offset: 0,
-				Length: 1,
-			},
-		},
-		NegativeDeltas: []int64{1, 2, -2, 1, -1, 0},
-		PositiveSpans: []prompb.BucketSpan{
-			{
-				Offset: 0,
-				Length: 4,
-			},
-			{
-				Offset: 0,
-				Length: 0,
-			},
-			{
-				Offset: 0,
-				Length: 3,
-			},
-		},
-		PositiveDeltas: []int64{1, 2, -2, 1, -1, 0, 0},
-		ResetHint:      prompb.Histogram_GAUGE,
-		Timestamp:      1337,
-	}
-}
-
-func TestHistogramToProtoConvert(t *testing.T) {
-	tests := []struct {
-		input    histogram.CounterResetHint
-		expected prompb.Histogram_ResetHint
-	}{
-		{
-			input:    histogram.UnknownCounterReset,
-			expected: prompb.Histogram_UNKNOWN,
-		},
-		{
-			input:    histogram.CounterReset,
-			expected: prompb.Histogram_YES,
-		},
-		{
-			input:    histogram.NotCounterReset,
-			expected: prompb.Histogram_NO,
-		},
-		{
-			input:    histogram.GaugeType,
-			expected: prompb.Histogram_GAUGE,
-		},
-	}
-
-	for _, test := range tests {
-		h := exampleHistogram()
-		h.CounterResetHint = test.input
-		p := exampleHistogramProto()
-		p.ResetHint = test.expected
-
-		require.Equal(t, p, HistogramToHistogramProto(1337, &h))
-
-		require.Equal(t, h, *HistogramProtoToHistogram(p))
-	}
-}
-
-func exampleFloatHistogram() histogram.FloatHistogram {
-	return histogram.FloatHistogram{
-		CounterResetHint: histogram.GaugeType,
-		Schema:           0,
-		Count:            19,
-		Sum:              2.7,
-		PositiveSpans: []histogram.Span{
-			{Offset: 0, Length: 4},
-			{Offset: 0, Length: 0},
-			{Offset: 0, Length: 3},
-		},
-		PositiveBuckets: []float64{1, 2, -2, 1, -1, 0, 0},
-		NegativeSpans: []histogram.Span{
-			{Offset: 0, Length: 5},
-			{Offset: 1, Length: 0},
-			{Offset: 0, Length: 1},
-		},
-		NegativeBuckets: []float64{1, 2, -2, 1, -1, 0},
-	}
-}
-
-func exampleFloatHistogramProto() prompb.Histogram {
-	return prompb.Histogram{
-		Count:         &prompb.Histogram_CountFloat{CountFloat: 19},
-		Sum:           2.7,
-		Schema:        0,
-		ZeroThreshold: 0,
-		ZeroCount:     &prompb.Histogram_ZeroCountFloat{ZeroCountFloat: 0},
-		NegativeSpans: []prompb.BucketSpan{
-			{
-				Offset: 0,
-				Length: 5,
-			},
-			{
-				Offset: 1,
-				Length: 0,
-			},
-			{
-				Offset: 0,
-				Length: 1,
-			},
-		},
-		NegativeCounts: []float64{1, 2, -2, 1, -1, 0},
-		PositiveSpans: []prompb.BucketSpan{
-			{
-				Offset: 0,
-				Length: 4,
-			},
-			{
-				Offset: 0,
-				Length: 0,
-			},
-			{
-				Offset: 0,
-				Length: 3,
-			},
-		},
-		PositiveCounts: []float64{1, 2, -2, 1, -1, 0, 0},
-		ResetHint:      prompb.Histogram_GAUGE,
-		Timestamp:      1337,
-	}
-}
-
-func TestFloatHistogramToProtoConvert(t *testing.T) {
-	tests := []struct {
-		input    histogram.CounterResetHint
-		expected prompb.Histogram_ResetHint
-	}{
-		{
-			input:    histogram.UnknownCounterReset,
-			expected: prompb.Histogram_UNKNOWN,
-		},
-		{
-			input:    histogram.CounterReset,
-			expected: prompb.Histogram_YES,
-		},
-		{
-			input:    histogram.NotCounterReset,
-			expected: prompb.Histogram_NO,
-		},
-		{
-			input:    histogram.GaugeType,
-			expected: prompb.Histogram_GAUGE,
-		},
-	}
-
-	for _, test := range tests {
-		h := exampleFloatHistogram()
-		h.CounterResetHint = test.input
-		p := exampleFloatHistogramProto()
-		p.ResetHint = test.expected
-
-		require.Equal(t, p, FloatHistogramToHistogramProto(1337, &h))
-
-		require.Equal(t, h, *FloatHistogramProtoToFloatHistogram(p))
-	}
-}
-
 func TestStreamResponse(t *testing.T) {
-	lbs1 := labelsToLabelsProto(labels.FromStrings("instance", "localhost1", "job", "demo1"), nil)
+	lbs1 := prompb.FromLabels(labels.FromStrings("instance", "localhost1", "job", "demo1"), nil)
-	lbs2 := labelsToLabelsProto(labels.FromStrings("instance", "localhost2", "job", "demo2"), nil)
+	lbs2 := prompb.FromLabels(labels.FromStrings("instance", "localhost2", "job", "demo2"), nil)
 	chunk := prompb.Chunk{
 		Type: prompb.Chunk_XOR,
 		Data: make([]byte, 100),
@@ -853,7 +604,7 @@ func (c *mockChunkSeriesSet) Next() bool {
 
 func (c *mockChunkSeriesSet) At() storage.ChunkSeries {
 	return &storage.ChunkSeriesEntry{
-		Lset: labelProtosToLabels(&c.builder, c.chunkedSeries[c.index].Labels),
+		Lset: c.chunkedSeries[c.index].ToLabels(&c.builder, nil),
 		ChunkIteratorFn: func(chunks.Iterator) chunks.Iterator {
 			return &mockChunkIterator{
 				chunks: c.chunkedSeries[c.index].Chunks,
@@ -895,3 +646,74 @@ func (c *mockChunkIterator) Next() bool {
 func (c *mockChunkIterator) Err() error {
 	return nil
 }
+
+func v2RequesToWriteRequest(v2Req *writev2.Request) (*prompb.WriteRequest, error) {
+	req := &prompb.WriteRequest{
+		Timeseries: make([]prompb.TimeSeries, len(v2Req.Timeseries)),
+		// TODO handle metadata?
+	}
+	b := labels.NewScratchBuilder(0)
+	for i, rts := range v2Req.Timeseries {
+		rts.ToLabels(&b, v2Req.Symbols).Range(func(l labels.Label) {
+			req.Timeseries[i].Labels = append(req.Timeseries[i].Labels, prompb.Label{
+				Name:  l.Name,
+				Value: l.Value,
+			})
+		})
+
+		exemplars := make([]prompb.Exemplar, len(rts.Exemplars))
+		for j, e := range rts.Exemplars {
+			exemplars[j].Value = e.Value
+			exemplars[j].Timestamp = e.Timestamp
+			e.ToExemplar(&b, v2Req.Symbols).Labels.Range(func(l labels.Label) {
+				exemplars[j].Labels = append(exemplars[j].Labels, prompb.Label{
+					Name:  l.Name,
+					Value: l.Value,
+				})
+			})
+		}
+		req.Timeseries[i].Exemplars = exemplars
+
+		req.Timeseries[i].Samples = make([]prompb.Sample, len(rts.Samples))
+		for j, s := range rts.Samples {
+			req.Timeseries[i].Samples[j].Timestamp = s.Timestamp
+			req.Timeseries[i].Samples[j].Value = s.Value
+		}
+
+		req.Timeseries[i].Histograms = make([]prompb.Histogram, len(rts.Histograms))
+		for j, h := range rts.Histograms {
+			// TODO: double check
+			if h.IsFloatHistogram() {
+				req.Timeseries[i].Histograms[j].Count = &prompb.Histogram_CountFloat{CountFloat: h.GetCountFloat()}
+				req.Timeseries[i].Histograms[j].ZeroCount = &prompb.Histogram_ZeroCountFloat{ZeroCountFloat: h.GetZeroCountFloat()}
+			} else {
+				req.Timeseries[i].Histograms[j].Count = &prompb.Histogram_CountInt{CountInt: h.GetCountInt()}
+				req.Timeseries[i].Histograms[j].ZeroCount = &prompb.Histogram_ZeroCountInt{ZeroCountInt: h.GetZeroCountInt()}
+			}
+
+			for _, span := range h.NegativeSpans {
+				req.Timeseries[i].Histograms[j].NegativeSpans = append(req.Timeseries[i].Histograms[j].NegativeSpans, prompb.BucketSpan{
+					Offset: span.Offset,
+					Length: span.Length,
+				})
+			}
+			for _, span := range h.PositiveSpans {
+				req.Timeseries[i].Histograms[j].PositiveSpans = append(req.Timeseries[i].Histograms[j].PositiveSpans, prompb.BucketSpan{
+					Offset: span.Offset,
+					Length: span.Length,
+				})
+			}
+
+			req.Timeseries[i].Histograms[j].Sum = h.Sum
+			req.Timeseries[i].Histograms[j].Schema = h.Schema
+			req.Timeseries[i].Histograms[j].ZeroThreshold = h.ZeroThreshold
+			req.Timeseries[i].Histograms[j].NegativeDeltas = h.NegativeDeltas
+			req.Timeseries[i].Histograms[j].NegativeCounts = h.NegativeCounts
+			req.Timeseries[i].Histograms[j].PositiveDeltas = h.PositiveDeltas
+			req.Timeseries[i].Histograms[j].PositiveCounts = h.PositiveCounts
+			req.Timeseries[i].Histograms[j].ResetHint = prompb.Histogram_ResetHint(h.ResetHint)
+			req.Timeseries[i].Histograms[j].Timestamp = h.Timestamp
+		}
+	}
+	return req, nil
+}

storage/remote/queue_manager.go

@@ -553,7 +553,7 @@ func (t *QueueManager) AppendWatcherMetadata(ctx context.Context, metadata []scr
 		mm = append(mm, prompb.MetricMetadata{
 			MetricFamilyName: entry.Metric,
 			Help:             entry.Help,
-			Type:             metricTypeToMetricTypeProto(entry.Type),
+			Type:             prompb.FromMetadataType(entry.Type),
 			Unit:             entry.Unit,
 		})
 	}
@@ -1624,7 +1624,7 @@ func populateTimeSeries(batch []timeSeries, pendingData []prompb.TimeSeries, sen
 		// Number of pending samples is limited by the fact that sendSamples (via sendSamplesWithBackoff)
 		// retries endlessly, so once we reach max samples, if we can never send to the endpoint we'll
 		// stop reading from the queue. This makes it safe to reference pendingSamples by index.
-		pendingData[nPending].Labels = labelsToLabelsProto(d.seriesLabels, pendingData[nPending].Labels)
+		pendingData[nPending].Labels = prompb.FromLabels(d.seriesLabels, pendingData[nPending].Labels)
 
 		switch d.sType {
 		case tSample:
@@ -1635,16 +1635,16 @@ func populateTimeSeries(batch []timeSeries, pendingData []prompb.TimeSeries, sen
 			nPendingSamples++
 		case tExemplar:
 			pendingData[nPending].Exemplars = append(pendingData[nPending].Exemplars, prompb.Exemplar{
-				Labels:    labelsToLabelsProto(d.exemplarLabels, nil),
+				Labels:    prompb.FromLabels(d.exemplarLabels, nil),
 				Value:     d.value,
 				Timestamp: d.timestamp,
 			})
 			nPendingExemplars++
 		case tHistogram:
-			pendingData[nPending].Histograms = append(pendingData[nPending].Histograms, HistogramToHistogramProto(d.timestamp, d.histogram))
+			pendingData[nPending].Histograms = append(pendingData[nPending].Histograms, prompb.FromIntHistogram(d.timestamp, d.histogram))
 			nPendingHistograms++
 		case tFloatHistogram:
-			pendingData[nPending].Histograms = append(pendingData[nPending].Histograms, FloatHistogramToHistogramProto(d.timestamp, d.floatHistogram))
+			pendingData[nPending].Histograms = append(pendingData[nPending].Histograms, prompb.FromFloatHistogram(d.timestamp, d.floatHistogram))
 			nPendingHistograms++
 		}
 	}
@@ -1876,7 +1876,7 @@ func populateV2TimeSeries(symbolTable *writev2.SymbolsTable, batch []timeSeries,
 		pendingData[nPending].Samples = pendingData[nPending].Samples[:0]
 		// todo: should we also safeguard against empty metadata here?
 		if d.metadata != nil {
-			pendingData[nPending].Metadata.Type = metricTypeToMetricTypeProtoV2(d.metadata.Type)
+			pendingData[nPending].Metadata.Type = writev2.FromMetadataType(d.metadata.Type)
 			pendingData[nPending].Metadata.HelpRef = symbolTable.Symbolize(d.metadata.Help)
 			pendingData[nPending].Metadata.HelpRef = symbolTable.Symbolize(d.metadata.Unit)
 			nPendingMetadata++
@@ -1908,10 +1908,10 @@ func populateV2TimeSeries(symbolTable *writev2.SymbolsTable, batch []timeSeries,
 			})
 			nPendingExemplars++
 		case tHistogram:
-			pendingData[nPending].Histograms = append(pendingData[nPending].Histograms, HistogramToV2HistogramProto(d.timestamp, d.histogram))
+			pendingData[nPending].Histograms = append(pendingData[nPending].Histograms, writev2.FromIntHistogram(d.timestamp, d.histogram))
 			nPendingHistograms++
 		case tFloatHistogram:
-			pendingData[nPending].Histograms = append(pendingData[nPending].Histograms, FloatHistogramToV2HistogramProto(d.timestamp, d.floatHistogram))
+			pendingData[nPending].Histograms = append(pendingData[nPending].Histograms, writev2.FromFloatHistogram(d.timestamp, d.floatHistogram))
 			nPendingHistograms++
 		case tMetadata:
 			// TODO: log or return an error?

storage/remote/queue_manager_test.go

@@ -1019,7 +1019,7 @@ func (c *TestWriteClient) expectExemplars(ss []record.RefExemplar, series []reco
 	for _, s := range ss {
 		seriesName := getSeriesNameFromRef(series[s.Ref])
 		e := prompb.Exemplar{
-			Labels:    labelsToLabelsProto(s.Labels, nil),
+			Labels:    prompb.FromLabels(s.Labels, nil),
 			Timestamp: s.T,
 			Value:     s.V,
 		}
@@ -1036,7 +1036,7 @@ func (c *TestWriteClient) expectHistograms(hh []record.RefHistogramSample, serie
 
 	for _, h := range hh {
 		seriesName := getSeriesNameFromRef(series[h.Ref])
-		c.expectedHistograms[seriesName] = append(c.expectedHistograms[seriesName], HistogramToHistogramProto(h.T, h.H))
+		c.expectedHistograms[seriesName] = append(c.expectedHistograms[seriesName], prompb.FromIntHistogram(h.T, h.H))
 	}
 }
 
@@ -1049,7 +1049,7 @@ func (c *TestWriteClient) expectFloatHistograms(fhs []record.RefFloatHistogramSa
 
 	for _, fh := range fhs {
 		seriesName := getSeriesNameFromRef(series[fh.Ref])
-		c.expectedFloatHistograms[seriesName] = append(c.expectedFloatHistograms[seriesName], FloatHistogramToHistogramProto(fh.T, fh.FH))
+		c.expectedFloatHistograms[seriesName] = append(c.expectedFloatHistograms[seriesName], prompb.FromFloatHistogram(fh.T, fh.FH))
 	}
 }
 
@@ -1133,7 +1133,7 @@ func (c *TestWriteClient) Store(_ context.Context, req []byte, _ int) error {
 		var reqProtoV2 writev2.Request
 		err = proto.Unmarshal(reqBuf, &reqProtoV2)
 		if err == nil {
-			reqProto, err = V2WriteRequestToWriteRequest(&reqProtoV2)
+			reqProto, err = v2RequesToWriteRequest(&reqProtoV2)
 		}
 	}
 	if err != nil {
@@ -1144,9 +1144,9 @@ func (c *TestWriteClient) Store(_ context.Context, req []byte, _ int) error {
 		return errors.New("invalid request, no timeseries")
 	}
 
-	builder := labels.NewScratchBuilder(0)
+	b := labels.NewScratchBuilder(0)
 	for _, ts := range reqProto.Timeseries {
-		labels := labelProtosToLabels(&builder, ts.Labels)
+		labels := ts.ToLabels(&b, nil)
 		seriesName := labels.Get("__name__")
 		c.receivedSamples[seriesName] = append(c.receivedSamples[seriesName], ts.Samples...)
 		if len(ts.Exemplars) > 0 {

storage/remote/read_handler_test.go

@@ -124,7 +124,7 @@ func TestSampledReadEndpoint(t *testing.T) {
 					{Name: "d", Value: "e"},
 				},
 				Histograms: []prompb.Histogram{
-					FloatHistogramToHistogramProto(0, tsdbutil.GenerateTestFloatHistogram(0)),
+					prompb.FromFloatHistogram(0, tsdbutil.GenerateTestFloatHistogram(0)),
 				},
 			},
 		},

storage/remote/read_test.go

@@ -173,12 +173,12 @@ func TestSeriesSetFilter(t *testing.T) {
 			toRemove: []string{"foo"},
 			in: &prompb.QueryResult{
 				Timeseries: []*prompb.TimeSeries{
-					{Labels: labelsToLabelsProto(labels.FromStrings("foo", "bar", "a", "b"), nil)},
+					{Labels: prompb.FromLabels(labels.FromStrings("foo", "bar", "a", "b"), nil)},
 				},
 			},
 			expected: &prompb.QueryResult{
 				Timeseries: []*prompb.TimeSeries{
-					{Labels: labelsToLabelsProto(labels.FromStrings("a", "b"), nil)},
+					{Labels: prompb.FromLabels(labels.FromStrings("a", "b"), nil)},
 				},
 			},
 		},
@@ -212,7 +212,7 @@ func (c *mockedRemoteClient) Read(_ context.Context, query *prompb.Query) (*prom
 
 	q := &prompb.QueryResult{}
 	for _, s := range c.store {
-		l := labelProtosToLabels(&c.b, s.Labels)
+		l := s.ToLabels(&c.b, nil)
 		var notMatch bool
 
 		for _, m := range matchers {

storage/remote/write_handler.go

@@ -218,7 +218,7 @@ func (h *writeHandler) write(ctx context.Context, req *prompb.WriteRequest) (err
 
 	b := labels.NewScratchBuilder(0)
 	for _, ts := range req.Timeseries {
-		ls := labelProtosToLabels(&b, ts.Labels)
+		ls := ts.ToLabels(&b, nil)
 		if !ls.IsValid() {
 			level.Warn(h.logger).Log("msg", "Invalid metric names or labels", "got", ls.String())
 			samplesWithInvalidLabels++
@@ -231,7 +231,7 @@ func (h *writeHandler) write(ctx context.Context, req *prompb.WriteRequest) (err
 		}
 
 		for _, ep := range ts.Exemplars {
-			e := exemplarProtoToExemplar(&b, ep)
+			e := ep.ToExemplar(&b, nil)
 			h.appendExemplar(app, e, ls, &outOfOrderExemplarErrs)
 		}
 
@@ -263,8 +263,9 @@ func (h *writeHandler) writeV2(ctx context.Context, req *writev2.Request) (err e
 		err = app.Commit()
 	}()
 
+	b := labels.NewScratchBuilder(0)
 	for _, ts := range req.Timeseries {
-		ls := writev2.DesymbolizeLabels(ts.LabelsRefs, req.Symbols)
+		ls := ts.ToLabels(&b, req.Symbols)
 
 		err := h.appendSamplesV2(app, ts.Samples, ls)
 		if err != nil {
@@ -272,7 +273,7 @@ func (h *writeHandler) writeV2(ctx context.Context, req *writev2.Request) (err e
 		}
 
 		for _, ep := range ts.Exemplars {
-			e := exemplarProtoV2ToExemplar(ep, req.Symbols)
+			e := ep.ToExemplar(&b, req.Symbols)
 			h.appendExemplar(app, e, ls, &outOfOrderExemplarErrs)
 		}
 
@@ -281,7 +282,7 @@ func (h *writeHandler) writeV2(ctx context.Context, req *writev2.Request) (err e
 			return err
 		}
 
-		m := metadataProtoV2ToMetadata(ts.Metadata, req.Symbols)
+		m := ts.ToMetadata(req.Symbols)
 		if _, err = app.UpdateMetadata(0, ls, m); err != nil {
 			level.Debug(h.logger).Log("msg", "error while updating metadata from remote write", "err", err)
 		}
@@ -345,11 +346,9 @@ func (h *writeHandler) appendHistograms(app storage.Appender, hh []prompb.Histog
 	var err error
 	for _, hp := range hh {
 		if hp.IsFloatHistogram() {
-			fhs := FloatHistogramProtoToFloatHistogram(hp)
+			_, err = app.AppendHistogram(0, labels, hp.Timestamp, nil, hp.ToFloatHistogram())
-			_, err = app.AppendHistogram(0, labels, hp.Timestamp, nil, fhs)
 		} else {
-			hs := HistogramProtoToHistogram(hp)
+			_, err = app.AppendHistogram(0, labels, hp.Timestamp, hp.ToIntHistogram(), nil)
-			_, err = app.AppendHistogram(0, labels, hp.Timestamp, hs, nil)
 		}
 		if err != nil {
 			unwrappedErr := errors.Unwrap(err)
@@ -371,11 +370,9 @@ func (h *writeHandler) appendHistogramsV2(app storage.Appender, hh []writev2.His
 	var err error
 	for _, hp := range hh {
 		if hp.IsFloatHistogram() {
-			fhs := FloatV2HistogramProtoToFloatHistogram(hp)
+			_, err = app.AppendHistogram(0, labels, hp.Timestamp, nil, hp.ToFloatHistogram())
-			_, err = app.AppendHistogram(0, labels, hp.Timestamp, nil, fhs)
 		} else {
-			hs := V2HistogramProtoToHistogram(hp)
+			_, err = app.AppendHistogram(0, labels, hp.Timestamp, hp.ToIntHistogram(), nil)
-			_, err = app.AppendHistogram(0, labels, hp.Timestamp, hs, nil)
 		}
 		if err != nil {
 			unwrappedErr := errors.Unwrap(err)

storage/remote/write_handler_test.go

@@ -266,24 +266,22 @@ func TestRemoteWriteHandler_V1Message(t *testing.T) {
 	j := 0
 	k := 0
 	for _, ts := range writeRequestFixture.Timeseries {
-		labels := labelProtosToLabels(&b, ts.Labels)
+		labels := ts.ToLabels(&b, nil)
 		for _, s := range ts.Samples {
 			requireEqual(t, mockSample{labels, s.Timestamp, s.Value}, appendable.samples[i])
 			i++
 		}
-
 		for _, e := range ts.Exemplars {
-			exemplarLabels := labelProtosToLabels(&b, e.Labels)
+			exemplarLabels := e.ToExemplar(&b, nil).Labels
 			requireEqual(t, mockExemplar{labels, exemplarLabels, e.Timestamp, e.Value}, appendable.exemplars[j])
 			j++
 		}
-
 		for _, hp := range ts.Histograms {
 			if hp.IsFloatHistogram() {
-				fh := FloatHistogramProtoToFloatHistogram(hp)
+				fh := hp.ToFloatHistogram()
 				requireEqual(t, mockHistogram{labels, hp.Timestamp, nil, fh}, appendable.histograms[k])
 			} else {
-				h := HistogramProtoToHistogram(hp)
+				h := hp.ToIntHistogram()
 				requireEqual(t, mockHistogram{labels, hp.Timestamp, h, nil}, appendable.histograms[k])
 			}
 
@@ -312,30 +310,62 @@ func TestRemoteWriteHandler_V2Message(t *testing.T) {
 	resp := recorder.Result()
 	require.Equal(t, http.StatusNoContent, resp.StatusCode)
 
+	b := labels.NewScratchBuilder(0)
 	i := 0
 	j := 0
 	k := 0
-	// the reduced write request is equivalent to the write request fixture.
-	// we can use it for
 	for _, ts := range writeV2RequestFixture.Timeseries {
-		ls := writev2.DesymbolizeLabels(ts.LabelsRefs, writeV2RequestFixture.Symbols)
+		ls := ts.ToLabels(&b, writeV2RequestFixture.Symbols)
 		for _, s := range ts.Samples {
-			require.Equal(t, mockSample{ls, s.Timestamp, s.Value}, appendable.samples[i])
+			// NOTE(bwplotka): In this case I got errors due to correct labels.Labels.String(), but with dedupelabels tag
+			// require.Equal(t, mockSample{ls, s.Timestamp, s.Value}, appendable.samples[i]) fails.
+			/*
+			   	Error Trace:	/Users/bwplotka/Repos/prometheus/storage/remote/write_handler_test.go:323
+			        	Error:      	Not equal:
+			        	           	expected: labels.Labels{syms:(*labels.nameTable)(0x1400095afc0), data:"\x00\x01\x02\x03\x04\x05\x06\a\b\t"}
+			        	           	actual  : labels.Labels{syms:(*labels.nameTable)(0x1400095b080), data:"\x00\x01\x02\x03\x04\x05\x06\a\b\t"}
+
+			        	           	Diff:
+			        	           	--- Expected
+			        	           	+++ Actual
+			        	           	@@ -13,4 +13,4 @@
+			        	           	   (string) (len=3) "bar",
+			        	           	-   (string) (len=1) "f",
+			        	           	-   (string) (len=1) "g",
+			        	           	+   (string) "",
+			        	           	+   (string) "",
+			        	           	   (string) "",
+			        	           	@@ -1034,4 +1034,4 @@
+			        	           	   nameTable: (*labels.nameTable)(<already shown>),
+			        	           	-   nextNum: (int) 12,
+			        	           	-   byName: (map[string]int) (len=12) {
+			        	           	+   nextNum: (int) 10,
+			        	           	+   byName: (map[string]int) (len=10) {
+			        	           	    (string) (len=8) "__name__": (int) 0,
+			        	           	@@ -1043,5 +1043,3 @@
+			        	           	    (string) (len=1) "e": (int) 7,
+			        	           	-    (string) (len=1) "f": (int) 10,
+			        	           	    (string) (len=3) "foo": (int) 8,
+			        	           	-    (string) (len=1) "g": (int) 11,
+			        	           	    (string) (len=3) "qux": (int) 5,
+			*/
+			// TODO(bwplotka): Investigate why, is it the way we do fixtures?
+			require.Equal(t, appendable.samples[i].l.String(), ls.String())
+			require.Equal(t, s.Value, appendable.samples[i].v)
+			require.Equal(t, s.Timestamp, appendable.samples[i].t)
 			i++
 		}
-
 		for _, e := range ts.Exemplars {
-			exemplarLabels := writev2.DesymbolizeLabels(e.LabelsRefs, writeV2RequestFixture.Symbols)
+			exemplarLabels := e.ToExemplar(&b, writeV2RequestFixture.Symbols).Labels
 			require.Equal(t, mockExemplar{ls, exemplarLabels, e.Timestamp, e.Value}, appendable.exemplars[j])
 			j++
 		}
-
 		for _, hp := range ts.Histograms {
 			if hp.IsFloatHistogram() {
-				fh := FloatHistogramProtoV2ToFloatHistogram(hp)
+				fh := hp.ToFloatHistogram()
 				require.Equal(t, mockHistogram{ls, hp.Timestamp, nil, fh}, appendable.histograms[k])
 			} else {
-				h := HistogramProtoV2ToHistogram(hp)
+				h := hp.ToIntHistogram()
 				require.Equal(t, mockHistogram{ls, hp.Timestamp, h, nil}, appendable.histograms[k])
 			}
 
@@ -442,7 +472,7 @@ func TestOutOfOrderExemplar_V2Message(t *testing.T) {
 func TestOutOfOrderHistogram_V1Message(t *testing.T) {
 	payload, _, _, err := buildWriteRequest(nil, []prompb.TimeSeries{{
 		Labels:     []prompb.Label{{Name: "__name__", Value: "test_metric"}},
-		Histograms: []prompb.Histogram{HistogramToHistogramProto(0, &testHistogram), FloatHistogramToHistogramProto(1, testHistogram.ToFloat(nil))},
+		Histograms: []prompb.Histogram{prompb.FromIntHistogram(0, &testHistogram), prompb.FromFloatHistogram(1, testHistogram.ToFloat(nil))},
 	}}, nil, nil, nil, nil, "snappy")
 	require.NoError(t, err)
 
@@ -462,7 +492,7 @@ func TestOutOfOrderHistogram_V1Message(t *testing.T) {
 func TestOutOfOrderHistogram_V2Message(t *testing.T) {
 	payload, _, _, err := buildV2WriteRequest(nil, []writev2.TimeSeries{{
 		LabelsRefs: []uint32{0, 1},
-		Histograms: []writev2.Histogram{HistogramToV2HistogramProto(0, &testHistogram), FloatHistogramToV2HistogramProto(1, testHistogram.ToFloat(nil))},
+		Histograms: []writev2.Histogram{writev2.FromIntHistogram(0, &testHistogram), writev2.FromFloatHistogram(1, testHistogram.ToFloat(nil))},
 	}}, []string{"__name__", "metric1"}, nil, nil, nil, "snappy") // TODO(bwplotka): No empty string!
 	require.NoError(t, err)
 
@@ -493,7 +523,7 @@ func BenchmarkRemoteWriteHandler(b *testing.B) {
 				{Name: "__name__", Value: "test_metric"},
 				{Name: "test_label_name_" + num, Value: labelValue + num},
 			},
-			Histograms: []prompb.Histogram{HistogramToHistogramProto(0, &testHistogram)},
+			Histograms: []prompb.Histogram{prompb.FromIntHistogram(0, &testHistogram)},
 		}}, nil, nil, nil, nil, "snappy")
 		require.NoError(b, err)
 		req, err := http.NewRequest("", "", bytes.NewReader(buf))