Move metric code to a separate package

CHANGELOG.md

@@ -31,7 +31,8 @@ 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` 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/metrictest` package into `go.opentelemetry.io/oteltest` as part of #964. (#1252)
+- Move the `go.opentelemetry.io/otel/api/metric` package into `go.opentelemetry.io/otel/metric` as part of #1303. (#1321)
 - 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)

example/basic/main.go

@@ -22,6 +22,7 @@ import (
 	"go.opentelemetry.io/otel/exporters/stdout"
 	"go.opentelemetry.io/otel/global"
 	"go.opentelemetry.io/otel/label"
+	"go.opentelemetry.io/otel/metric"
 	"go.opentelemetry.io/otel/propagators"
 	"go.opentelemetry.io/otel/sdk/metric/controller/push"
 	"go.opentelemetry.io/otel/sdk/metric/processor/basic"
@@ -68,14 +69,14 @@ func main() {
 
 	commonLabels := []label.KeyValue{lemonsKey.Int(10), label.String("A", "1"), label.String("B", "2"), label.String("C", "3")}
 
-	oneMetricCB := func(_ context.Context, result otel.Float64ObserverResult) {
+	oneMetricCB := func(_ context.Context, result metric.Float64ObserverResult) {
 		result.Observe(1, commonLabels...)
 	}
-	_ = otel.Must(meter).NewFloat64ValueObserver("ex.com.one", oneMetricCB,
-		otel.WithDescription("A ValueObserver set to 1.0"),
+	_ = metric.Must(meter).NewFloat64ValueObserver("ex.com.one", oneMetricCB,
+		metric.WithDescription("A ValueObserver set to 1.0"),
 	)
 
-	valuerecorderTwo := otel.Must(meter).NewFloat64ValueRecorder("ex.com.two")
+	valuerecorderTwo := metric.Must(meter).NewFloat64ValueRecorder("ex.com.two")
 
 	ctx := context.Background()
 	ctx = otel.ContextWithBaggageValues(ctx, fooKey.String("foo1"), barKey.String("bar1"))

example/otel-collector/main.go

@@ -25,10 +25,10 @@ import (
 
 	"google.golang.org/grpc"
 
-	"go.opentelemetry.io/otel"
 	"go.opentelemetry.io/otel/exporters/otlp"
 	"go.opentelemetry.io/otel/global"
 	"go.opentelemetry.io/otel/label"
+	"go.opentelemetry.io/otel/metric"
 	"go.opentelemetry.io/otel/propagators"
 	"go.opentelemetry.io/otel/sdk/metric/controller/push"
 	"go.opentelemetry.io/otel/sdk/metric/processor/basic"
@@ -111,10 +111,10 @@ func main() {
 	}
 
 	// Recorder metric example
-	valuerecorder := otel.Must(meter).
+	valuerecorder := metric.Must(meter).
 		NewFloat64Counter(
 			"an_important_metric",
-			otel.WithDescription("Measures the cumulative epicness of the app"),
+			metric.WithDescription("Measures the cumulative epicness of the app"),
 		).Bind(commonLabels...)
 	defer valuerecorder.Unbind()
 

example/prometheus/main.go

@@ -22,10 +22,10 @@ import (
 	"sync"
 	"time"
 
-	"go.opentelemetry.io/otel"
 	"go.opentelemetry.io/otel/exporters/metric/prometheus"
 	"go.opentelemetry.io/otel/global"
 	"go.opentelemetry.io/otel/label"
+	"go.opentelemetry.io/otel/metric"
 )
 
 var (
@@ -52,19 +52,19 @@ func main() {
 	observerLock := new(sync.RWMutex)
 	observerValueToReport := new(float64)
 	observerLabelsToReport := new([]label.KeyValue)
-	cb := func(_ context.Context, result otel.Float64ObserverResult) {
+	cb := func(_ context.Context, result metric.Float64ObserverResult) {
 		(*observerLock).RLock()
 		value := *observerValueToReport
 		labels := *observerLabelsToReport
 		(*observerLock).RUnlock()
 		result.Observe(value, labels...)
 	}
-	_ = otel.Must(meter).NewFloat64ValueObserver("ex.com.one", cb,
-		otel.WithDescription("A ValueObserver set to 1.0"),
+	_ = metric.Must(meter).NewFloat64ValueObserver("ex.com.one", cb,
+		metric.WithDescription("A ValueObserver set to 1.0"),
 	)
 
-	valuerecorder := otel.Must(meter).NewFloat64ValueRecorder("ex.com.two")
-	counter := otel.Must(meter).NewFloat64Counter("ex.com.three")
+	valuerecorder := metric.Must(meter).NewFloat64ValueRecorder("ex.com.two")
+	counter := metric.Must(meter).NewFloat64Counter("ex.com.three")
 
 	commonLabels := []label.KeyValue{lemonsKey.Int(10), label.String("A", "1"), label.String("B", "2"), label.String("C", "3")}
 	notSoCommonLabels := []label.KeyValue{lemonsKey.Int(13)}

exporters/metric/prometheus/example_test.go

@@ -22,9 +22,9 @@ import (
 	"net/http"
 	"net/http/httptest"
 
-	"go.opentelemetry.io/otel"
 	"go.opentelemetry.io/otel/exporters/metric/prometheus"
 	"go.opentelemetry.io/otel/label"
+	"go.opentelemetry.io/otel/metric"
 	"go.opentelemetry.io/otel/sdk/metric/controller/pull"
 	"go.opentelemetry.io/otel/sdk/resource"
 )
@@ -59,13 +59,13 @@ func ExampleNewExportPipeline() {
 	ctx := context.Background()
 
 	// Use two instruments
-	counter := otel.Must(meter).NewInt64Counter(
+	counter := metric.Must(meter).NewInt64Counter(
 		"a.counter",
-		otel.WithDescription("Counts things"),
+		metric.WithDescription("Counts things"),
 	)
-	recorder := otel.Must(meter).NewInt64ValueRecorder(
+	recorder := metric.Must(meter).NewInt64ValueRecorder(
 		"a.valuerecorder",
-		otel.WithDescription("Records values"),
+		metric.WithDescription("Records values"),
 	)
 
 	counter.Add(ctx, 100, label.String("key", "value"))

exporters/metric/prometheus/prometheus.go

@@ -23,9 +23,9 @@ import (
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/prometheus/client_golang/prometheus/promhttp"
 
-	"go.opentelemetry.io/otel"
 	"go.opentelemetry.io/otel/global"
 	"go.opentelemetry.io/otel/label"
+	"go.opentelemetry.io/otel/metric"
 	"go.opentelemetry.io/otel/metric/number"
 	export "go.opentelemetry.io/otel/sdk/export/metric"
 	"go.opentelemetry.io/otel/sdk/export/metric/aggregation"
@@ -156,7 +156,7 @@ func (e *Exporter) SetController(config Config, options ...pull.Option) {
 }
 
 // MeterProvider returns the MeterProvider of this exporter.
-func (e *Exporter) MeterProvider() otel.MeterProvider {
+func (e *Exporter) MeterProvider() metric.MeterProvider {
 	return e.controller.MeterProvider()
 }
 
@@ -167,7 +167,7 @@ func (e *Exporter) Controller() *pull.Controller {
 	return e.controller
 }
 
-func (e *Exporter) ExportKindFor(desc *otel.Descriptor, kind aggregation.Kind) export.ExportKind {
+func (e *Exporter) ExportKindFor(desc *metric.Descriptor, kind aggregation.Kind) export.ExportKind {
 	// NOTE: Summary values should use Delta aggregation, then be
 	// combined into a sliding window, see the TODO below.
 	// NOTE: Prometheus also supports a "GaugeDelta" exposition format,

exporters/metric/prometheus/prometheus_test.go

@@ -26,9 +26,9 @@ import (
 
 	"github.com/stretchr/testify/require"
 
-	"go.opentelemetry.io/otel"
 	"go.opentelemetry.io/otel/exporters/metric/prometheus"
 	"go.opentelemetry.io/otel/label"
+	"go.opentelemetry.io/otel/metric"
 	"go.opentelemetry.io/otel/sdk/metric/controller/pull"
 	"go.opentelemetry.io/otel/sdk/resource"
 )
@@ -48,9 +48,9 @@ func TestPrometheusExporter(t *testing.T) {
 	require.NoError(t, err)
 
 	meter := exporter.MeterProvider().Meter("test")
-	upDownCounter := otel.Must(meter).NewFloat64UpDownCounter("updowncounter")
-	counter := otel.Must(meter).NewFloat64Counter("counter")
-	valuerecorder := otel.Must(meter).NewFloat64ValueRecorder("valuerecorder")
+	upDownCounter := metric.Must(meter).NewFloat64UpDownCounter("updowncounter")
+	counter := metric.Must(meter).NewFloat64Counter("counter")
+	valuerecorder := metric.Must(meter).NewFloat64ValueRecorder("valuerecorder")
 
 	labels := []label.KeyValue{
 		label.Key("A").String("B"),
@@ -65,7 +65,7 @@ func TestPrometheusExporter(t *testing.T) {
 
 	expected = append(expected, `counter{A="B",C="D",R="V"} 15.3`)
 
-	_ = otel.Must(meter).NewInt64ValueObserver("intobserver", func(_ context.Context, result otel.Int64ObserverResult) {
+	_ = metric.Must(meter).NewInt64ValueObserver("intobserver", func(_ context.Context, result metric.Int64ObserverResult) {
 		result.Observe(1, labels...)
 	})
 
@@ -138,9 +138,9 @@ func TestPrometheusStatefulness(t *testing.T) {
 
 	ctx := context.Background()
 
-	counter := otel.Must(meter).NewInt64Counter(
+	counter := metric.Must(meter).NewInt64Counter(
 		"a.counter",
-		otel.WithDescription("Counts things"),
+		metric.WithDescription("Counts things"),
 	)
 
 	counter.Add(ctx, 100, label.String("key", "value"))

exporters/otlp/internal/transform/metric_test.go

@@ -26,9 +26,8 @@ import (
 
 	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"
 	"go.opentelemetry.io/otel/metric/number"
 	export "go.opentelemetry.io/otel/sdk/export/metric"
 	"go.opentelemetry.io/otel/sdk/export/metric/aggregation"
@@ -102,17 +101,17 @@ func TestStringKeyValues(t *testing.T) {
 }
 
 func TestMinMaxSumCountValue(t *testing.T) {
-	mmsc, ckpt := metrictest.Unslice2(minmaxsumcount.New(2, &otel.Descriptor{}))
+	mmsc, ckpt := metrictest.Unslice2(minmaxsumcount.New(2, &metric.Descriptor{}))
 
-	assert.NoError(t, mmsc.Update(context.Background(), 1, &otel.Descriptor{}))
-	assert.NoError(t, mmsc.Update(context.Background(), 10, &otel.Descriptor{}))
+	assert.NoError(t, mmsc.Update(context.Background(), 1, &metric.Descriptor{}))
+	assert.NoError(t, mmsc.Update(context.Background(), 10, &metric.Descriptor{}))
 
 	// Prior to checkpointing ErrNoData should be returned.
 	_, _, _, _, err := minMaxSumCountValues(ckpt.(aggregation.MinMaxSumCount))
 	assert.EqualError(t, err, aggregation.ErrNoData.Error())
 
 	// Checkpoint to set non-zero values
-	require.NoError(t, mmsc.SynchronizedMove(ckpt, &otel.Descriptor{}))
+	require.NoError(t, mmsc.SynchronizedMove(ckpt, &metric.Descriptor{}))
 	min, max, sum, count, err := minMaxSumCountValues(ckpt.(aggregation.MinMaxSumCount))
 	if assert.NoError(t, err) {
 		assert.Equal(t, min, number.NewInt64Number(1))
@@ -123,7 +122,7 @@ func TestMinMaxSumCountValue(t *testing.T) {
 }
 
 func TestMinMaxSumCountDatapoints(t *testing.T) {
-	desc := otel.NewDescriptor("", otel.ValueRecorderInstrumentKind, number.Int64Kind)
+	desc := metric.NewDescriptor("", metric.ValueRecorderInstrumentKind, number.Int64Kind)
 	labels := label.NewSet()
 	mmsc, ckpt := metrictest.Unslice2(minmaxsumcount.New(2, &desc))
 
@@ -155,14 +154,14 @@ func TestMinMaxSumCountPropagatesErrors(t *testing.T) {
 	// ErrNoData should be returned by both the Min and Max values of
 	// a MinMaxSumCount Aggregator. Use this fact to check the error is
 	// correctly returned.
-	mmsc := &minmaxsumcount.New(1, &otel.Descriptor{})[0]
+	mmsc := &minmaxsumcount.New(1, &metric.Descriptor{})[0]
 	_, _, _, _, err := minMaxSumCountValues(mmsc)
 	assert.Error(t, err)
 	assert.Equal(t, aggregation.ErrNoData, err)
 }
 
 func TestSumIntDataPoints(t *testing.T) {
-	desc := otel.NewDescriptor("", otel.ValueRecorderInstrumentKind, number.Int64Kind)
+	desc := metric.NewDescriptor("", metric.ValueRecorderInstrumentKind, number.Int64Kind)
 	labels := label.NewSet()
 	s, ckpt := metrictest.Unslice2(sumAgg.New(2))
 	assert.NoError(t, s.Update(context.Background(), number.Number(1), &desc))
@@ -190,7 +189,7 @@ func TestSumIntDataPoints(t *testing.T) {
 }
 
 func TestSumFloatDataPoints(t *testing.T) {
-	desc := otel.NewDescriptor("", otel.ValueRecorderInstrumentKind, number.Float64Kind)
+	desc := metric.NewDescriptor("", metric.ValueRecorderInstrumentKind, number.Float64Kind)
 	labels := label.NewSet()
 	s, ckpt := metrictest.Unslice2(sumAgg.New(2))
 	assert.NoError(t, s.Update(context.Background(), number.NewFloat64Number(1), &desc))
@@ -219,7 +218,7 @@ func TestSumFloatDataPoints(t *testing.T) {
 }
 
 func TestLastValueIntDataPoints(t *testing.T) {
-	desc := otel.NewDescriptor("", otel.ValueRecorderInstrumentKind, number.Int64Kind)
+	desc := metric.NewDescriptor("", metric.ValueRecorderInstrumentKind, number.Int64Kind)
 	labels := label.NewSet()
 	s, ckpt := metrictest.Unslice2(lvAgg.New(2))
 	assert.NoError(t, s.Update(context.Background(), number.Number(100), &desc))
@@ -245,7 +244,7 @@ func TestLastValueIntDataPoints(t *testing.T) {
 }
 
 func TestSumErrUnknownValueType(t *testing.T) {
-	desc := otel.NewDescriptor("", otel.ValueRecorderInstrumentKind, number.Kind(-1))
+	desc := metric.NewDescriptor("", metric.ValueRecorderInstrumentKind, number.Kind(-1))
 	labels := label.NewSet()
 	s := &sumAgg.New(1)[0]
 	record := export.NewRecord(&desc, &labels, nil, s, intervalStart, intervalEnd)
@@ -274,13 +273,13 @@ func (t *testAgg) Aggregation() aggregation.Aggregation {
 
 // None of these three are used:
 
-func (t *testAgg) Update(ctx context.Context, number number.Number, descriptor *otel.Descriptor) error {
+func (t *testAgg) Update(ctx context.Context, number number.Number, descriptor *metric.Descriptor) error {
 	return nil
 }
-func (t *testAgg) SynchronizedMove(destination export.Aggregator, descriptor *otel.Descriptor) error {
+func (t *testAgg) SynchronizedMove(destination export.Aggregator, descriptor *metric.Descriptor) error {
 	return nil
 }
-func (t *testAgg) Merge(aggregator export.Aggregator, descriptor *otel.Descriptor) error {
+func (t *testAgg) Merge(aggregator export.Aggregator, descriptor *metric.Descriptor) error {
 	return nil
 }
 
@@ -330,7 +329,7 @@ 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, number.Int64Kind)
+		desc := metric.NewDescriptor("things", metric.CounterInstrumentKind, number.Int64Kind)
 		labels := label.NewSet()
 		res := resource.Empty()
 		test := &testAgg{
@@ -367,7 +366,7 @@ 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, number.Int64Kind)
+		desc := metric.NewDescriptor("things", metric.CounterInstrumentKind, number.Int64Kind)
 		labels := label.NewSet()
 		res := resource.Empty()
 		return Record(export.CumulativeExportKindSelector(), export.NewRecord(&desc, &labels, res, agg, intervalStart, intervalEnd))

exporters/otlp/otlp.go

@@ -27,11 +27,10 @@ import (
 	"google.golang.org/grpc"
 	"google.golang.org/grpc/metadata"
 
-	"go.opentelemetry.io/otel"
 	colmetricpb "go.opentelemetry.io/otel/exporters/otlp/internal/opentelemetry-proto-gen/collector/metrics/v1"
 	coltracepb "go.opentelemetry.io/otel/exporters/otlp/internal/opentelemetry-proto-gen/collector/trace/v1"
-
 	"go.opentelemetry.io/otel/exporters/otlp/internal/transform"
+	"go.opentelemetry.io/otel/metric"
 	metricsdk "go.opentelemetry.io/otel/sdk/export/metric"
 	"go.opentelemetry.io/otel/sdk/export/metric/aggregation"
 	tracesdk "go.opentelemetry.io/otel/sdk/export/trace"
@@ -289,7 +288,7 @@ func (e *Exporter) Export(parent context.Context, cps metricsdk.CheckpointSet) e
 
 // ExportKindFor reports back to the OpenTelemetry SDK sending this Exporter
 // metric telemetry that it needs to be provided in a cumulative format.
-func (e *Exporter) ExportKindFor(desc *otel.Descriptor, kind aggregation.Kind) metricsdk.ExportKind {
+func (e *Exporter) ExportKindFor(desc *metric.Descriptor, kind aggregation.Kind) metricsdk.ExportKind {
 	return e.c.exportKindSelector.ExportKindFor(desc, kind)
 }