Prepare to move metrics code to separate subpackage (#1316)

* Move registry package under metric

* Move Number type to the metric/number subpackage

This also renames NumberKind type to Kind.

* Update changelog

* Drop outdated comment

CHANGELOG.md

@@ -31,7 +31,9 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
    This matches the returned type and fixes misuse of the term metric. (#1240)
 - Move test harness from the `go.opentelemetry.io/otel/api/apitest` package into `go.opentelemetry.io/otel/oteltest`. (#1241)
 - Rename `MergeItererator` to `MergeIterator` in the `go.opentelemetry.io/otel/label` package. (#1244)
-- Move the `go.opentelemetry.io/otel/api/metric`, `go.opentelemetry.io/otel/api/metric/metrictest`, and `go.opentelemetry.io/otel/api/metric/registry` packages into `go.opentelemetry.io/otel` as part of #964. (#1252)
+- Move the `go.opentelemetry.io/otel/api/metric` and `go.opentelemetry.io/otel/api/metric/metrictest` packages into `go.opentelemetry.io/otel` as part of #964. (#1252)
+- Move the `go.opentelemetry.io/otel/api/metric/registry` package into `go.opentelemetry.io/otel/metric/registry as a part of #1303. (#1316)
+- Move the `Number` type (together with related functions) from `go.opentelemetry.io/otel/api/metric` package into `go.opentelemetry.io/otel/metric/number` as a part of #1303. (#1316)
 - The function signature of the Span `AddEvent` method in `go.opentelemetry.io/otel` is updated to no longer take an unused context and instead take a required name and a variable number of `EventOption`s. (#1254)
 - The function signature of the Span `RecordError` method in `go.opentelemetry.io/otel` is updated to no longer take an unused context and instead take a required error value and a variable number of `EventOption`s. (#1254)
 - Move the `go.opentelemetry.io/otel/api/global` package to `go.opentelemetry.io/otel/global`. (#1262)

exporters/metric/prometheus/example_test.go

@@ -32,7 +32,7 @@ import (
 // This test demonstrates that it is relatively difficult to setup a
 // Prometheus export pipeline:
 //
-//   1. The default boundaries are difficult to pass, should be []float instead of []otel.Number
+//   1. The default boundaries are difficult to pass, should be []float instead of []number.Number
 //
 // TODO: Address this issue.
 

exporters/metric/prometheus/prometheus.go

@@ -26,6 +26,7 @@ import (
 	"go.opentelemetry.io/otel"
 	"go.opentelemetry.io/otel/global"
 	"go.opentelemetry.io/otel/label"
+	"go.opentelemetry.io/otel/metric/number"
 	export "go.opentelemetry.io/otel/sdk/export/metric"
 	"go.opentelemetry.io/otel/sdk/export/metric/aggregation"
 	"go.opentelemetry.io/otel/sdk/metric/controller/pull"
@@ -257,7 +258,7 @@ func (c *collector) Collect(ch chan<- prometheus.Metric) {
 	}
 }
 
-func (c *collector) exportLastValue(ch chan<- prometheus.Metric, lvagg aggregation.LastValue, kind otel.NumberKind, desc *prometheus.Desc, labels []string) error {
+func (c *collector) exportLastValue(ch chan<- prometheus.Metric, lvagg aggregation.LastValue, kind number.Kind, desc *prometheus.Desc, labels []string) error {
 	lv, _, err := lvagg.LastValue()
 	if err != nil {
 		return fmt.Errorf("error retrieving last value: %w", err)
@@ -272,7 +273,7 @@ func (c *collector) exportLastValue(ch chan<- prometheus.Metric, lvagg aggregati
 	return nil
 }
 
-func (c *collector) exportNonMonotonicCounter(ch chan<- prometheus.Metric, sum aggregation.Sum, kind otel.NumberKind, desc *prometheus.Desc, labels []string) error {
+func (c *collector) exportNonMonotonicCounter(ch chan<- prometheus.Metric, sum aggregation.Sum, kind number.Kind, desc *prometheus.Desc, labels []string) error {
 	v, err := sum.Sum()
 	if err != nil {
 		return fmt.Errorf("error retrieving counter: %w", err)
@@ -287,7 +288,7 @@ func (c *collector) exportNonMonotonicCounter(ch chan<- prometheus.Metric, sum a
 	return nil
 }
 
-func (c *collector) exportMonotonicCounter(ch chan<- prometheus.Metric, sum aggregation.Sum, kind otel.NumberKind, desc *prometheus.Desc, labels []string) error {
+func (c *collector) exportMonotonicCounter(ch chan<- prometheus.Metric, sum aggregation.Sum, kind number.Kind, desc *prometheus.Desc, labels []string) error {
 	v, err := sum.Sum()
 	if err != nil {
 		return fmt.Errorf("error retrieving counter: %w", err)
@@ -302,13 +303,13 @@ func (c *collector) exportMonotonicCounter(ch chan<- prometheus.Metric, sum aggr
 	return nil
 }
 
-func (c *collector) exportSummary(ch chan<- prometheus.Metric, dist aggregation.Distribution, kind otel.NumberKind, desc *prometheus.Desc, labels []string) error {
+func (c *collector) exportSummary(ch chan<- prometheus.Metric, dist aggregation.Distribution, kind number.Kind, desc *prometheus.Desc, labels []string) error {
 	count, err := dist.Count()
 	if err != nil {
 		return fmt.Errorf("error retrieving count: %w", err)
 	}
 
-	var sum otel.Number
+	var sum number.Number
 	sum, err = dist.Sum()
 	if err != nil {
 		return fmt.Errorf("error retrieving distribution sum: %w", err)
@@ -329,7 +330,7 @@ func (c *collector) exportSummary(ch chan<- prometheus.Metric, dist aggregation.
 	return nil
 }
 
-func (c *collector) exportHistogram(ch chan<- prometheus.Metric, hist aggregation.Histogram, kind otel.NumberKind, desc *prometheus.Desc, labels []string) error {
+func (c *collector) exportHistogram(ch chan<- prometheus.Metric, hist aggregation.Histogram, kind number.Kind, desc *prometheus.Desc, labels []string) error {
 	buckets, err := hist.Histogram()
 	if err != nil {
 		return fmt.Errorf("error retrieving histogram: %w", err)

exporters/otlp/internal/transform/metric.go

@@ -24,12 +24,12 @@ import (
 	"sync"
 	"time"
 
-	"go.opentelemetry.io/otel"
 	commonpb "go.opentelemetry.io/otel/exporters/otlp/internal/opentelemetry-proto-gen/common/v1"
 	metricpb "go.opentelemetry.io/otel/exporters/otlp/internal/opentelemetry-proto-gen/metrics/v1"
 	resourcepb "go.opentelemetry.io/otel/exporters/otlp/internal/opentelemetry-proto-gen/resource/v1"
 
 	"go.opentelemetry.io/otel/label"
+	"go.opentelemetry.io/otel/metric/number"
 	export "go.opentelemetry.io/otel/sdk/export/metric"
 	"go.opentelemetry.io/otel/sdk/export/metric/aggregation"
 	"go.opentelemetry.io/otel/sdk/instrumentation"
@@ -294,7 +294,7 @@ func Record(exportSelector export.ExportKindSelector, r export.Record) (*metricp
 	}
 }
 
-func gaugePoint(record export.Record, num otel.Number, start, end time.Time) (*metricpb.Metric, error) {
+func gaugePoint(record export.Record, num number.Number, start, end time.Time) (*metricpb.Metric, error) {
 	desc := record.Descriptor()
 	labels := record.Labels()
 
@@ -305,7 +305,7 @@ func gaugePoint(record export.Record, num otel.Number, start, end time.Time) (*m
 	}
 
 	switch n := desc.NumberKind(); n {
-	case otel.Int64NumberKind:
+	case number.Int64Kind:
 		m.Data = &metricpb.Metric_IntGauge{
 			IntGauge: &metricpb.IntGauge{
 				DataPoints: []*metricpb.IntDataPoint{
@@ -318,7 +318,7 @@ func gaugePoint(record export.Record, num otel.Number, start, end time.Time) (*m
 				},
 			},
 		}
-	case otel.Float64NumberKind:
+	case number.Float64Kind:
 		m.Data = &metricpb.Metric_DoubleGauge{
 			DoubleGauge: &metricpb.DoubleGauge{
 				DataPoints: []*metricpb.DoubleDataPoint{
@@ -348,7 +348,7 @@ func exportKindToTemporality(ek export.ExportKind) metricpb.AggregationTemporali
 	return metricpb.AggregationTemporality_AGGREGATION_TEMPORALITY_UNSPECIFIED
 }
 
-func sumPoint(record export.Record, num otel.Number, start, end time.Time, ek export.ExportKind, monotonic bool) (*metricpb.Metric, error) {
+func sumPoint(record export.Record, num number.Number, start, end time.Time, ek export.ExportKind, monotonic bool) (*metricpb.Metric, error) {
 	desc := record.Descriptor()
 	labels := record.Labels()
 
@@ -359,7 +359,7 @@ func sumPoint(record export.Record, num otel.Number, start, end time.Time, ek ex
 	}
 
 	switch n := desc.NumberKind(); n {
-	case otel.Int64NumberKind:
+	case number.Int64Kind:
 		m.Data = &metricpb.Metric_IntSum{
 			IntSum: &metricpb.IntSum{
 				IsMonotonic:            monotonic,
@@ -374,7 +374,7 @@ func sumPoint(record export.Record, num otel.Number, start, end time.Time, ek ex
 				},
 			},
 		}
-	case otel.Float64NumberKind:
+	case number.Float64Kind:
 		m.Data = &metricpb.Metric_DoubleSum{
 			DoubleSum: &metricpb.DoubleSum{
 				IsMonotonic:            monotonic,
@@ -398,7 +398,7 @@ func sumPoint(record export.Record, num otel.Number, start, end time.Time, ek ex
 
 // minMaxSumCountValue returns the values of the MinMaxSumCount Aggregator
 // as discrete values.
-func minMaxSumCountValues(a aggregation.MinMaxSumCount) (min, max, sum otel.Number, count int64, err error) {
+func minMaxSumCountValues(a aggregation.MinMaxSumCount) (min, max, sum number.Number, count int64, err error) {
 	if min, err = a.Min(); err != nil {
 		return
 	}
@@ -433,7 +433,7 @@ func minMaxSumCount(record export.Record, a aggregation.MinMaxSumCount) (*metric
 	bounds := []float64{0.0, 100.0}
 
 	switch n := desc.NumberKind(); n {
-	case otel.Int64NumberKind:
+	case number.Int64Kind:
 		m.Data = &metricpb.Metric_IntHistogram{
 			IntHistogram: &metricpb.IntHistogram{
 				DataPoints: []*metricpb.IntHistogramDataPoint{
@@ -449,7 +449,7 @@ func minMaxSumCount(record export.Record, a aggregation.MinMaxSumCount) (*metric
 				},
 			},
 		}
-	case otel.Float64NumberKind:
+	case number.Float64Kind:
 		m.Data = &metricpb.Metric_DoubleHistogram{
 			DoubleHistogram: &metricpb.DoubleHistogram{
 				DataPoints: []*metricpb.DoubleHistogramDataPoint{
@@ -513,7 +513,7 @@ func histogramPoint(record export.Record, ek export.ExportKind, a aggregation.Hi
 		Unit:        string(desc.Unit()),
 	}
 	switch n := desc.NumberKind(); n {
-	case otel.Int64NumberKind:
+	case number.Int64Kind:
 		m.Data = &metricpb.Metric_IntHistogram{
 			IntHistogram: &metricpb.IntHistogram{
 				AggregationTemporality: exportKindToTemporality(ek),
@@ -530,7 +530,7 @@ func histogramPoint(record export.Record, ek export.ExportKind, a aggregation.Hi
 				},
 			},
 		}
-	case otel.Float64NumberKind:
+	case number.Float64Kind:
 		m.Data = &metricpb.Metric_DoubleHistogram{
 			DoubleHistogram: &metricpb.DoubleHistogram{
 				AggregationTemporality: exportKindToTemporality(ek),

exporters/otlp/internal/transform/metric_test.go

@@ -24,11 +24,12 @@ import (
 	"github.com/stretchr/testify/assert"
 	"github.com/stretchr/testify/require"
 
-	"go.opentelemetry.io/otel"
 	commonpb "go.opentelemetry.io/otel/exporters/otlp/internal/opentelemetry-proto-gen/common/v1"
 	metricpb "go.opentelemetry.io/otel/exporters/otlp/internal/opentelemetry-proto-gen/metrics/v1"
 
+	"go.opentelemetry.io/otel"
 	"go.opentelemetry.io/otel/label"
+	"go.opentelemetry.io/otel/metric/number"
 	export "go.opentelemetry.io/otel/sdk/export/metric"
 	"go.opentelemetry.io/otel/sdk/export/metric/aggregation"
 	"go.opentelemetry.io/otel/sdk/export/metric/metrictest"
@@ -114,15 +115,15 @@ func TestMinMaxSumCountValue(t *testing.T) {
 	require.NoError(t, mmsc.SynchronizedMove(ckpt, &otel.Descriptor{}))
 	min, max, sum, count, err := minMaxSumCountValues(ckpt.(aggregation.MinMaxSumCount))
 	if assert.NoError(t, err) {
-		assert.Equal(t, min, otel.NewInt64Number(1))
-		assert.Equal(t, max, otel.NewInt64Number(10))
-		assert.Equal(t, sum, otel.NewInt64Number(11))
+		assert.Equal(t, min, number.NewInt64Number(1))
+		assert.Equal(t, max, number.NewInt64Number(10))
+		assert.Equal(t, sum, number.NewInt64Number(11))
 		assert.Equal(t, count, int64(2))
 	}
 }
 
 func TestMinMaxSumCountDatapoints(t *testing.T) {
-	desc := otel.NewDescriptor("", otel.ValueRecorderInstrumentKind, otel.Int64NumberKind)
+	desc := otel.NewDescriptor("", otel.ValueRecorderInstrumentKind, number.Int64Kind)
 	labels := label.NewSet()
 	mmsc, ckpt := metrictest.Unslice2(minmaxsumcount.New(2, &desc))
 
@@ -161,10 +162,10 @@ func TestMinMaxSumCountPropagatesErrors(t *testing.T) {
 }
 
 func TestSumIntDataPoints(t *testing.T) {
-	desc := otel.NewDescriptor("", otel.ValueRecorderInstrumentKind, otel.Int64NumberKind)
+	desc := otel.NewDescriptor("", otel.ValueRecorderInstrumentKind, number.Int64Kind)
 	labels := label.NewSet()
 	s, ckpt := metrictest.Unslice2(sumAgg.New(2))
-	assert.NoError(t, s.Update(context.Background(), otel.Number(1), &desc))
+	assert.NoError(t, s.Update(context.Background(), number.Number(1), &desc))
 	require.NoError(t, s.SynchronizedMove(ckpt, &desc))
 	record := export.NewRecord(&desc, &labels, nil, ckpt.Aggregation(), intervalStart, intervalEnd)
 	sum, ok := ckpt.(aggregation.Sum)
@@ -189,10 +190,10 @@ func TestSumIntDataPoints(t *testing.T) {
 }
 
 func TestSumFloatDataPoints(t *testing.T) {
-	desc := otel.NewDescriptor("", otel.ValueRecorderInstrumentKind, otel.Float64NumberKind)
+	desc := otel.NewDescriptor("", otel.ValueRecorderInstrumentKind, number.Float64Kind)
 	labels := label.NewSet()
 	s, ckpt := metrictest.Unslice2(sumAgg.New(2))
-	assert.NoError(t, s.Update(context.Background(), otel.NewFloat64Number(1), &desc))
+	assert.NoError(t, s.Update(context.Background(), number.NewFloat64Number(1), &desc))
 	require.NoError(t, s.SynchronizedMove(ckpt, &desc))
 	record := export.NewRecord(&desc, &labels, nil, ckpt.Aggregation(), intervalStart, intervalEnd)
 	sum, ok := ckpt.(aggregation.Sum)
@@ -218,10 +219,10 @@ func TestSumFloatDataPoints(t *testing.T) {
 }
 
 func TestLastValueIntDataPoints(t *testing.T) {
-	desc := otel.NewDescriptor("", otel.ValueRecorderInstrumentKind, otel.Int64NumberKind)
+	desc := otel.NewDescriptor("", otel.ValueRecorderInstrumentKind, number.Int64Kind)
 	labels := label.NewSet()
 	s, ckpt := metrictest.Unslice2(lvAgg.New(2))
-	assert.NoError(t, s.Update(context.Background(), otel.Number(100), &desc))
+	assert.NoError(t, s.Update(context.Background(), number.Number(100), &desc))
 	require.NoError(t, s.SynchronizedMove(ckpt, &desc))
 	record := export.NewRecord(&desc, &labels, nil, ckpt.Aggregation(), intervalStart, intervalEnd)
 	sum, ok := ckpt.(aggregation.LastValue)
@@ -244,7 +245,7 @@ func TestLastValueIntDataPoints(t *testing.T) {
 }
 
 func TestSumErrUnknownValueType(t *testing.T) {
-	desc := otel.NewDescriptor("", otel.ValueRecorderInstrumentKind, otel.NumberKind(-1))
+	desc := otel.NewDescriptor("", otel.ValueRecorderInstrumentKind, number.Kind(-1))
 	labels := label.NewSet()
 	s := &sumAgg.New(1)[0]
 	record := export.NewRecord(&desc, &labels, nil, s, intervalStart, intervalEnd)
@@ -273,7 +274,7 @@ func (t *testAgg) Aggregation() aggregation.Aggregation {
 
 // None of these three are used:
 
-func (t *testAgg) Update(ctx context.Context, number otel.Number, descriptor *otel.Descriptor) error {
+func (t *testAgg) Update(ctx context.Context, number number.Number, descriptor *otel.Descriptor) error {
 	return nil
 }
 func (t *testAgg) SynchronizedMove(destination export.Aggregator, descriptor *otel.Descriptor) error {
@@ -295,25 +296,25 @@ type testErrMinMaxSumCount struct {
 	testErrSum
 }
 
-func (te *testErrLastValue) LastValue() (otel.Number, time.Time, error) {
+func (te *testErrLastValue) LastValue() (number.Number, time.Time, error) {
 	return 0, time.Time{}, te.err
 }
 func (te *testErrLastValue) Kind() aggregation.Kind {
 	return aggregation.LastValueKind
 }
 
-func (te *testErrSum) Sum() (otel.Number, error) {
+func (te *testErrSum) Sum() (number.Number, error) {
 	return 0, te.err
 }
 func (te *testErrSum) Kind() aggregation.Kind {
 	return aggregation.SumKind
 }
 
-func (te *testErrMinMaxSumCount) Min() (otel.Number, error) {
+func (te *testErrMinMaxSumCount) Min() (number.Number, error) {
 	return 0, te.err
 }
 
-func (te *testErrMinMaxSumCount) Max() (otel.Number, error) {
+func (te *testErrMinMaxSumCount) Max() (number.Number, error) {
 	return 0, te.err
 }
 
@@ -329,7 +330,7 @@ var _ aggregation.MinMaxSumCount = &testErrMinMaxSumCount{}
 
 func TestRecordAggregatorIncompatibleErrors(t *testing.T) {
 	makeMpb := func(kind aggregation.Kind, agg aggregation.Aggregation) (*metricpb.Metric, error) {
-		desc := otel.NewDescriptor("things", otel.CounterInstrumentKind, otel.Int64NumberKind)
+		desc := otel.NewDescriptor("things", otel.CounterInstrumentKind, number.Int64Kind)
 		labels := label.NewSet()
 		res := resource.Empty()
 		test := &testAgg{
@@ -366,7 +367,7 @@ func TestRecordAggregatorIncompatibleErrors(t *testing.T) {
 
 func TestRecordAggregatorUnexpectedErrors(t *testing.T) {
 	makeMpb := func(kind aggregation.Kind, agg aggregation.Aggregation) (*metricpb.Metric, error) {
-		desc := otel.NewDescriptor("things", otel.CounterInstrumentKind, otel.Int64NumberKind)
+		desc := otel.NewDescriptor("things", otel.CounterInstrumentKind, number.Int64Kind)
 		labels := label.NewSet()
 		res := resource.Empty()
 		return Record(export.CumulativeExportKindSelector(), export.NewRecord(&desc, &labels, res, agg, intervalStart, intervalEnd))