Move metric no-op implementation to metric package

This is to be consistent with trace package.

Fixes: #2767

Signed-off-by: Bogdan Drutu <bogdandrutu@gmail.com>

metric/example_test.go

@@ -20,16 +20,16 @@ import (
 	"runtime"
 	"time"
 
+	"go.opentelemetry.io/otel/metric"
 	"go.opentelemetry.io/otel/metric/instrument"
 	"go.opentelemetry.io/otel/metric/instrument/syncfloat64"
-	"go.opentelemetry.io/otel/metric/nonrecording"
 	"go.opentelemetry.io/otel/metric/unit"
 )
 
 //nolint:govet // Meter doesn't register for go vet
 func ExampleMeter_synchronous() {
 	// In a library or program this would be provided by otel.GetMeterProvider().
-	meterProvider := nonrecording.NewNoopMeterProvider()
+	meterProvider := metric.NewNoopMeterProvider()
 
 	workDuration, err := meterProvider.Meter("go.opentelemetry.io/otel/metric#SyncExample").SyncInt64().Histogram(
 		"workDuration",
@@ -50,7 +50,7 @@ func ExampleMeter_synchronous() {
 //nolint:govet // Meter doesn't register for go vet
 func ExampleMeter_asynchronous_single() {
 	// In a library or program this would be provided by otel.GetMeterProvider().
-	meterProvider := nonrecording.NewNoopMeterProvider()
+	meterProvider := metric.NewNoopMeterProvider()
 	meter := meterProvider.Meter("go.opentelemetry.io/otel/metric#AsyncExample")
 
 	memoryUsage, err := meter.AsyncInt64().Gauge(
@@ -79,7 +79,7 @@ func ExampleMeter_asynchronous_single() {
 
 //nolint:govet // Meter doesn't register for go vet
 func ExampleMeter_asynchronous_multiple() {
-	meterProvider := nonrecording.NewNoopMeterProvider()
+	meterProvider := metric.NewNoopMeterProvider()
 	meter := meterProvider.Meter("go.opentelemetry.io/otel/metric#MultiAsyncExample")
 
 	// This is just a sample of memory stats to record from the Memstats

metric/internal/global/instruments_test.go

@@ -21,7 +21,6 @@ import (
 	"go.opentelemetry.io/otel/attribute"
 	"go.opentelemetry.io/otel/metric"
 	"go.opentelemetry.io/otel/metric/instrument"
-	"go.opentelemetry.io/otel/metric/nonrecording"
 )
 
 func testFloat64Race(interact func(context.Context, float64, ...attribute.KeyValue), setDelegate func(metric.Meter)) {
@@ -37,7 +36,7 @@ func testFloat64Race(interact func(context.Context, float64, ...attribute.KeyVal
 		}
 	}()
 
-	setDelegate(nonrecording.NewNoopMeter())
+	setDelegate(metric.NewNoopMeter())
 	close(finish)
 }
 
@@ -54,7 +53,7 @@ func testInt64Race(interact func(context.Context, int64, ...attribute.KeyValue),
 		}
 	}()
 
-	setDelegate(nonrecording.NewNoopMeter())
+	setDelegate(metric.NewNoopMeter())
 	close(finish)
 }
 

metric/internal/global/meter_test.go

@@ -27,7 +27,6 @@ import (
 	"go.opentelemetry.io/otel/metric/instrument"
 	"go.opentelemetry.io/otel/metric/instrument/asyncfloat64"
 	"go.opentelemetry.io/otel/metric/instrument/syncfloat64"
-	"go.opentelemetry.io/otel/metric/nonrecording"
 )
 
 func TestMeterProviderRace(t *testing.T) {
@@ -44,7 +43,7 @@ func TestMeterProviderRace(t *testing.T) {
 		}
 	}()
 
-	mp.setDelegate(nonrecording.NewNoopMeterProvider())
+	mp.setDelegate(metric.NewNoopMeterProvider())
 	close(finish)
 
 }
@@ -84,7 +83,7 @@ func TestMeterRace(t *testing.T) {
 	}()
 
 	wg.Wait()
-	mtr.setDelegate(nonrecording.NewNoopMeterProvider())
+	mtr.setDelegate(metric.NewNoopMeterProvider())
 	close(finish)
 }
 

metric/internal/global/state_test.go

@@ -21,7 +21,6 @@ import (
 	"github.com/stretchr/testify/assert"
 
 	"go.opentelemetry.io/otel/metric"
-	"go.opentelemetry.io/otel/metric/nonrecording"
 )
 
 func resetGlobalMeterProvider() {
@@ -55,7 +54,7 @@ func TestSetMeterProvider(t *testing.T) {
 	t.Run("First Set() should replace the delegate", func(t *testing.T) {
 		resetGlobalMeterProvider()
 
-		SetMeterProvider(nonrecording.NewNoopMeterProvider())
+		SetMeterProvider(metric.NewNoopMeterProvider())
 
 		_, ok := MeterProvider().(*meterProvider)
 		if ok {
@@ -68,7 +67,7 @@ func TestSetMeterProvider(t *testing.T) {
 
 		mp := MeterProvider()
 
-		SetMeterProvider(nonrecording.NewNoopMeterProvider())
+		SetMeterProvider(metric.NewNoopMeterProvider())
 
 		dmp := mp.(*meterProvider)
 

metric/nonrecording/instruments.go → metric/noop.go

@@ -12,7 +12,7 @@
 // See the License for the specific language governing permissions and
 // limitations under the License.
 
-package nonrecording // import "go.opentelemetry.io/otel/metric/nonrecording"
+package metric // import "go.opentelemetry.io/otel/metric"
 
 import (
 	"context"
@@ -25,6 +25,40 @@ import (
 	"go.opentelemetry.io/otel/metric/instrument/syncint64"
 )
 
+// NewNoopMeterProvider creates a MeterProvider that does not record any metrics.
+func NewNoopMeterProvider() MeterProvider {
+	return noopMeterProvider{}
+}
+
+type noopMeterProvider struct{}
+
+func (noopMeterProvider) Meter(string, ...MeterOption) Meter {
+	return noopMeter{}
+}
+
+// NewNoopMeter creates a Meter that does not record any metrics.
+func NewNoopMeter() Meter {
+	return noopMeter{}
+}
+
+type noopMeter struct{}
+
+func (noopMeter) AsyncInt64() asyncint64.InstrumentProvider {
+	return nonrecordingAsyncInt64Instrument{}
+}
+func (noopMeter) AsyncFloat64() asyncfloat64.InstrumentProvider {
+	return nonrecordingAsyncFloat64Instrument{}
+}
+func (noopMeter) SyncInt64() syncint64.InstrumentProvider {
+	return nonrecordingSyncInt64Instrument{}
+}
+func (noopMeter) SyncFloat64() syncfloat64.InstrumentProvider {
+	return nonrecordingSyncFloat64Instrument{}
+}
+func (noopMeter) RegisterCallback([]instrument.Asynchronous, func(context.Context)) error {
+	return nil
+}
+
 type nonrecordingAsyncFloat64Instrument struct {
 	instrument.Asynchronous
 }
@@ -36,15 +70,15 @@ var (
 	_ asyncfloat64.Gauge              = nonrecordingAsyncFloat64Instrument{}
 )
 
-func (n nonrecordingAsyncFloat64Instrument) Counter(name string, opts ...instrument.Option) (asyncfloat64.Counter, error) {
+func (n nonrecordingAsyncFloat64Instrument) Counter(string, ...instrument.Option) (asyncfloat64.Counter, error) {
 	return n, nil
 }
 
-func (n nonrecordingAsyncFloat64Instrument) UpDownCounter(name string, opts ...instrument.Option) (asyncfloat64.UpDownCounter, error) {
+func (n nonrecordingAsyncFloat64Instrument) UpDownCounter(string, ...instrument.Option) (asyncfloat64.UpDownCounter, error) {
 	return n, nil
 }
 
-func (n nonrecordingAsyncFloat64Instrument) Gauge(name string, opts ...instrument.Option) (asyncfloat64.Gauge, error) {
+func (n nonrecordingAsyncFloat64Instrument) Gauge(string, ...instrument.Option) (asyncfloat64.Gauge, error) {
 	return n, nil
 }
 
@@ -63,15 +97,15 @@ var (
 	_ asyncint64.Gauge              = nonrecordingAsyncInt64Instrument{}
 )
 
-func (n nonrecordingAsyncInt64Instrument) Counter(name string, opts ...instrument.Option) (asyncint64.Counter, error) {
+func (n nonrecordingAsyncInt64Instrument) Counter(string, ...instrument.Option) (asyncint64.Counter, error) {
 	return n, nil
 }
 
-func (n nonrecordingAsyncInt64Instrument) UpDownCounter(name string, opts ...instrument.Option) (asyncint64.UpDownCounter, error) {
+func (n nonrecordingAsyncInt64Instrument) UpDownCounter(string, ...instrument.Option) (asyncint64.UpDownCounter, error) {
 	return n, nil
 }
 
-func (n nonrecordingAsyncInt64Instrument) Gauge(name string, opts ...instrument.Option) (asyncint64.Gauge, error) {
+func (n nonrecordingAsyncInt64Instrument) Gauge(string, ...instrument.Option) (asyncint64.Gauge, error) {
 	return n, nil
 }
 
@@ -89,15 +123,15 @@ var (
 	_ syncfloat64.Histogram          = nonrecordingSyncFloat64Instrument{}
 )
 
-func (n nonrecordingSyncFloat64Instrument) Counter(name string, opts ...instrument.Option) (syncfloat64.Counter, error) {
+func (n nonrecordingSyncFloat64Instrument) Counter(string, ...instrument.Option) (syncfloat64.Counter, error) {
 	return n, nil
 }
 
-func (n nonrecordingSyncFloat64Instrument) UpDownCounter(name string, opts ...instrument.Option) (syncfloat64.UpDownCounter, error) {
+func (n nonrecordingSyncFloat64Instrument) UpDownCounter(string, ...instrument.Option) (syncfloat64.UpDownCounter, error) {
 	return n, nil
 }
 
-func (n nonrecordingSyncFloat64Instrument) Histogram(name string, opts ...instrument.Option) (syncfloat64.Histogram, error) {
+func (n nonrecordingSyncFloat64Instrument) Histogram(string, ...instrument.Option) (syncfloat64.Histogram, error) {
 	return n, nil
 }
 
@@ -120,15 +154,15 @@ var (
 	_ syncint64.Histogram          = nonrecordingSyncInt64Instrument{}
 )
 
-func (n nonrecordingSyncInt64Instrument) Counter(name string, opts ...instrument.Option) (syncint64.Counter, error) {
+func (n nonrecordingSyncInt64Instrument) Counter(string, ...instrument.Option) (syncint64.Counter, error) {
 	return n, nil
 }
 
-func (n nonrecordingSyncInt64Instrument) UpDownCounter(name string, opts ...instrument.Option) (syncint64.UpDownCounter, error) {
+func (n nonrecordingSyncInt64Instrument) UpDownCounter(string, ...instrument.Option) (syncint64.UpDownCounter, error) {
 	return n, nil
 }
 
-func (n nonrecordingSyncInt64Instrument) Histogram(name string, opts ...instrument.Option) (syncint64.Histogram, error) {
+func (n nonrecordingSyncInt64Instrument) Histogram(string, ...instrument.Option) (syncint64.Histogram, error) {
 	return n, nil
 }