[Proposal] Refactor view implementation

example/view/main.go

@@ -30,7 +30,6 @@ import (
 	"go.opentelemetry.io/otel/sdk/instrumentation"
 	"go.opentelemetry.io/otel/sdk/metric"
 	"go.opentelemetry.io/otel/sdk/metric/aggregation"
-	"go.opentelemetry.io/otel/sdk/metric/view"
 )
 
 const meterName = "github.com/open-telemetry/opentelemetry-go/example/view"
@@ -45,30 +44,22 @@ func main() {
 	}
 
 	// View to customize histogram buckets and rename a single histogram instrument.
-	customBucketsView, err := view.New(
-		// Match* to match instruments
-		view.MatchInstrumentName("custom_histogram"),
-		view.MatchInstrumentationScope(instrumentation.Scope{Name: meterName}),
-
-		// With* to modify instruments
-		view.WithSetAggregation(aggregation.ExplicitBucketHistogram{
-			Boundaries: []float64{64, 128, 256, 512, 1024, 2048, 4096},
-		}),
-		view.WithRename("bar"),
+	customBucketsView := metric.NewView(
+		metric.Instrument{
+			Name:  "custom_histogram",
+			Scope: instrumentation.Scope{Name: meterName},
+		},
+		metric.Stream{
+			Instrument: metric.Instrument{Name: "bar"},
+			Aggregation: aggregation.ExplicitBucketHistogram{
+				Boundaries: []float64{64, 128, 256, 512, 1024, 2048, 4096},
+			},
+		},
 	)
-	if err != nil {
-		log.Fatal(err)
-	}
-
-	// Default view to keep all instruments
-	defaultView, err := view.New(view.MatchInstrumentName("*"))
-	if err != nil {
-		log.Fatal(err)
-	}
 
 	provider := metric.NewMeterProvider(
 		metric.WithReader(exporter),
-		metric.WithView(customBucketsView, defaultView),
+		metric.WithView(customBucketsView),
 	)
 	meter := provider.Meter(meterName)
 

exporters/otlp/otlpmetric/client.go

@@ -17,19 +17,19 @@ package otlpmetric // import "go.opentelemetry.io/otel/exporters/otlp/otlpmetric
 import (
 	"context"
 
+	"go.opentelemetry.io/otel/sdk/metric"
 	"go.opentelemetry.io/otel/sdk/metric/aggregation"
 	"go.opentelemetry.io/otel/sdk/metric/metricdata"
-	"go.opentelemetry.io/otel/sdk/metric/view"
 	mpb "go.opentelemetry.io/proto/otlp/metrics/v1"
 )
 
 // Client handles the transmission of OTLP data to an OTLP receiving endpoint.
 type Client interface {
 	// Temporality returns the Temporality to use for an instrument kind.
-	Temporality(view.InstrumentKind) metricdata.Temporality
+	Temporality(metric.InstrumentKind) metricdata.Temporality
 
 	// Aggregation returns the Aggregation to use for an instrument kind.
-	Aggregation(view.InstrumentKind) aggregation.Aggregation
+	Aggregation(metric.InstrumentKind) aggregation.Aggregation
 
 	// UploadMetrics transmits metric data to an OTLP receiver.
 	//

exporters/otlp/otlpmetric/exporter.go

@@ -23,7 +23,6 @@ import (
 	"go.opentelemetry.io/otel/sdk/metric"
 	"go.opentelemetry.io/otel/sdk/metric/aggregation"
 	"go.opentelemetry.io/otel/sdk/metric/metricdata"
-	"go.opentelemetry.io/otel/sdk/metric/view"
 	mpb "go.opentelemetry.io/proto/otlp/metrics/v1"
 )
 
@@ -37,14 +36,14 @@ type exporter struct {
 }
 
 // Temporality returns the Temporality to use for an instrument kind.
-func (e *exporter) Temporality(k view.InstrumentKind) metricdata.Temporality {
+func (e *exporter) Temporality(k metric.InstrumentKind) metricdata.Temporality {
 	e.clientMu.Lock()
 	defer e.clientMu.Unlock()
 	return e.client.Temporality(k)
 }
 
 // Aggregation returns the Aggregation to use for an instrument kind.
-func (e *exporter) Aggregation(k view.InstrumentKind) aggregation.Aggregation {
+func (e *exporter) Aggregation(k metric.InstrumentKind) aggregation.Aggregation {
 	e.clientMu.Lock()
 	defer e.clientMu.Unlock()
 	return e.client.Aggregation(k)
@@ -113,11 +112,11 @@ func (c shutdownClient) err(ctx context.Context) error {
 	return errShutdown
 }
 
-func (c shutdownClient) Temporality(k view.InstrumentKind) metricdata.Temporality {
+func (c shutdownClient) Temporality(k metric.InstrumentKind) metricdata.Temporality {
 	return c.temporalitySelector(k)
 }
 
-func (c shutdownClient) Aggregation(k view.InstrumentKind) aggregation.Aggregation {
+func (c shutdownClient) Aggregation(k metric.InstrumentKind) aggregation.Aggregation {
 	return c.aggregationSelector(k)
 }
 

exporters/otlp/otlpmetric/exporter_test.go

@@ -24,7 +24,6 @@ import (
 	"go.opentelemetry.io/otel/sdk/metric"
 	"go.opentelemetry.io/otel/sdk/metric/aggregation"
 	"go.opentelemetry.io/otel/sdk/metric/metricdata"
-	"go.opentelemetry.io/otel/sdk/metric/view"
 	mpb "go.opentelemetry.io/proto/otlp/metrics/v1"
 )
 
@@ -34,11 +33,11 @@ type client struct {
 	n int
 }
 
-func (c *client) Temporality(k view.InstrumentKind) metricdata.Temporality {
+func (c *client) Temporality(k metric.InstrumentKind) metricdata.Temporality {
 	return metric.DefaultTemporalitySelector(k)
 }
 
-func (c *client) Aggregation(k view.InstrumentKind) aggregation.Aggregation {
+func (c *client) Aggregation(k metric.InstrumentKind) aggregation.Aggregation {
 	return metric.DefaultAggregationSelector(k)
 }
 

exporters/otlp/otlpmetric/internal/oconf/options.go

@@ -30,7 +30,6 @@ import (
 	"go.opentelemetry.io/otel/internal/global"
 	"go.opentelemetry.io/otel/sdk/metric"
 	"go.opentelemetry.io/otel/sdk/metric/aggregation"
-	"go.opentelemetry.io/otel/sdk/metric/view"
 )
 
 const (
@@ -336,7 +335,7 @@ func WithTemporalitySelector(selector metric.TemporalitySelector) GenericOption
 
 func WithAggregationSelector(selector metric.AggregationSelector) GenericOption {
 	// Deep copy and validate before using.
-	wrapped := func(ik view.InstrumentKind) aggregation.Aggregation {
+	wrapped := func(ik metric.InstrumentKind) aggregation.Aggregation {
 		a := selector(ik)
 		cpA := a.Copy()
 		if err := cpA.Err(); err != nil {

exporters/otlp/otlpmetric/internal/oconf/options_test.go

@@ -23,9 +23,9 @@ import (
 
 	"go.opentelemetry.io/otel/exporters/otlp/internal/envconfig"
 	"go.opentelemetry.io/otel/exporters/otlp/otlpmetric/internal/oconf"
+	"go.opentelemetry.io/otel/sdk/metric"
 	"go.opentelemetry.io/otel/sdk/metric/aggregation"
 	"go.opentelemetry.io/otel/sdk/metric/metricdata"
-	"go.opentelemetry.io/otel/sdk/metric/view"
 )
 
 const (
@@ -397,7 +397,7 @@ func TestConfigs(t *testing.T) {
 				// Function value comparisons are disallowed, test non-default
 				// behavior of a TemporalitySelector here to ensure our "catch
 				// all" was set.
-				var undefinedKind view.InstrumentKind
+				var undefinedKind metric.InstrumentKind
 				got := c.Metrics.TemporalitySelector
 				assert.Equal(t, metricdata.DeltaTemporality, got(undefinedKind))
 			},
@@ -413,7 +413,7 @@ func TestConfigs(t *testing.T) {
 				// Function value comparisons are disallowed, test non-default
 				// behavior of a AggregationSelector here to ensure our "catch
 				// all" was set.
-				var undefinedKind view.InstrumentKind
+				var undefinedKind metric.InstrumentKind
 				got := c.Metrics.AggregationSelector
 				assert.Equal(t, aggregation.Drop{}, got(undefinedKind))
 			},
@@ -441,11 +441,11 @@ func TestConfigs(t *testing.T) {
 	}
 }
 
-func dropSelector(view.InstrumentKind) aggregation.Aggregation {
+func dropSelector(metric.InstrumentKind) aggregation.Aggregation {
 	return aggregation.Drop{}
 }
 
-func deltaSelector(view.InstrumentKind) metricdata.Temporality {
+func deltaSelector(metric.InstrumentKind) metricdata.Temporality {
 	return metricdata.DeltaTemporality
 }
 

exporters/otlp/otlpmetric/internal/otest/client_test.go

@@ -22,7 +22,6 @@ import (
 	"go.opentelemetry.io/otel/sdk/metric"
 	"go.opentelemetry.io/otel/sdk/metric/aggregation"
 	"go.opentelemetry.io/otel/sdk/metric/metricdata"
-	"go.opentelemetry.io/otel/sdk/metric/view"
 	cpb "go.opentelemetry.io/proto/otlp/collector/metrics/v1"
 	mpb "go.opentelemetry.io/proto/otlp/metrics/v1"
 )
@@ -31,11 +30,11 @@ type client struct {
 	storage *Storage
 }
 
-func (c *client) Temporality(k view.InstrumentKind) metricdata.Temporality {
+func (c *client) Temporality(k metric.InstrumentKind) metricdata.Temporality {
 	return metric.DefaultTemporalitySelector(k)
 }
 
-func (c *client) Aggregation(k view.InstrumentKind) aggregation.Aggregation {
+func (c *client) Aggregation(k metric.InstrumentKind) aggregation.Aggregation {
 	return metric.DefaultAggregationSelector(k)
 }
 

exporters/otlp/otlpmetric/otlpmetricgrpc/client.go

@@ -30,7 +30,6 @@ import (
 	"go.opentelemetry.io/otel/sdk/metric"
 	"go.opentelemetry.io/otel/sdk/metric/aggregation"
 	"go.opentelemetry.io/otel/sdk/metric/metricdata"
-	"go.opentelemetry.io/otel/sdk/metric/view"
 	colmetricpb "go.opentelemetry.io/proto/otlp/collector/metrics/v1"
 	metricpb "go.opentelemetry.io/proto/otlp/metrics/v1"
 )
@@ -104,12 +103,12 @@ func newClient(ctx context.Context, options ...Option) (otlpmetric.Client, error
 }
 
 // Temporality returns the Temporality to use for an instrument kind.
-func (c *client) Temporality(k view.InstrumentKind) metricdata.Temporality {
+func (c *client) Temporality(k metric.InstrumentKind) metricdata.Temporality {
 	return c.temporalitySelector(k)
 }
 
 // Aggregation returns the Aggregation to use for an instrument kind.
-func (c *client) Aggregation(k view.InstrumentKind) aggregation.Aggregation {
+func (c *client) Aggregation(k metric.InstrumentKind) aggregation.Aggregation {
 	return c.aggregationSelector(k)
 }
 

exporters/otlp/otlpmetric/otlpmetrichttp/client.go

@@ -36,7 +36,6 @@ import (
 	"go.opentelemetry.io/otel/sdk/metric"
 	"go.opentelemetry.io/otel/sdk/metric/aggregation"
 	"go.opentelemetry.io/otel/sdk/metric/metricdata"
-	"go.opentelemetry.io/otel/sdk/metric/view"
 	colmetricpb "go.opentelemetry.io/proto/otlp/collector/metrics/v1"
 	metricpb "go.opentelemetry.io/proto/otlp/metrics/v1"
 )
@@ -129,12 +128,12 @@ func newClient(opts ...Option) (otlpmetric.Client, error) {
 }
 
 // Temporality returns the Temporality to use for an instrument kind.
-func (c *client) Temporality(k view.InstrumentKind) metricdata.Temporality {
+func (c *client) Temporality(k metric.InstrumentKind) metricdata.Temporality {
 	return c.temporalitySelector(k)
 }
 
 // Aggregation returns the Aggregation to use for an instrument kind.
-func (c *client) Aggregation(k view.InstrumentKind) aggregation.Aggregation {
+func (c *client) Aggregation(k metric.InstrumentKind) aggregation.Aggregation {
 	return c.aggregationSelector(k)
 }
 

exporters/prometheus/config_test.go

@@ -20,14 +20,14 @@ import (
 	"github.com/prometheus/client_golang/prometheus"
 	"github.com/stretchr/testify/assert"
 
+	"go.opentelemetry.io/otel/sdk/metric"
 	"go.opentelemetry.io/otel/sdk/metric/aggregation"
-	"go.opentelemetry.io/otel/sdk/metric/view"
 )
 
 func TestNewConfig(t *testing.T) {
 	registry := prometheus.NewRegistry()
 
-	aggregationSelector := func(view.InstrumentKind) aggregation.Aggregation { return nil }
+	aggregationSelector := func(metric.InstrumentKind) aggregation.Aggregation { return nil }
 
 	testCases := []struct {
 		name       string
@@ -112,7 +112,7 @@ func TestNewConfig(t *testing.T) {
 }
 
 func TestConfigManualReaderOptions(t *testing.T) {
-	aggregationSelector := func(view.InstrumentKind) aggregation.Aggregation { return nil }
+	aggregationSelector := func(metric.InstrumentKind) aggregation.Aggregation { return nil }
 
 	testCases := []struct {
 		name            string

exporters/prometheus/exporter_test.go

@@ -30,7 +30,6 @@ import (
 	"go.opentelemetry.io/otel/metric/unit"
 	"go.opentelemetry.io/otel/sdk/metric"
 	"go.opentelemetry.io/otel/sdk/metric/aggregation"
-	"go.opentelemetry.io/otel/sdk/metric/view"
 	"go.opentelemetry.io/otel/sdk/resource"
 	semconv "go.opentelemetry.io/otel/semconv/v1.12.0"
 )
@@ -269,16 +268,6 @@ func TestPrometheusExporter(t *testing.T) {
 			exporter, err := New(append(tc.options, WithRegisterer(registry))...)
 			require.NoError(t, err)
 
-			customBucketsView, err := view.New(
-				view.MatchInstrumentName("histogram_*"),
-				view.WithSetAggregation(aggregation.ExplicitBucketHistogram{
-					Boundaries: []float64{0, 5, 10, 25, 50, 75, 100, 250, 500, 1000},
-				}),
-			)
-			require.NoError(t, err)
-			defaultView, err := view.New(view.MatchInstrumentName("*"))
-			require.NoError(t, err)
-
 			var res *resource.Resource
 
 			if tc.emptyResource {
@@ -300,7 +289,14 @@ func TestPrometheusExporter(t *testing.T) {
 			provider := metric.NewMeterProvider(
 				metric.WithResource(res),
 				metric.WithReader(exporter),
-				metric.WithView(customBucketsView, defaultView),
+				metric.WithView(metric.NewView(
+					metric.Instrument{Name: "histogram_*"},
+					metric.Stream{
+						Aggregation: aggregation.ExplicitBucketHistogram{
+							Boundaries: []float64{0, 5, 10, 25, 50, 75, 100, 250, 500, 1000},
+						},
+					},
+				)),
 			)
 			meter := provider.Meter(
 				"testmeter",

exporters/stdout/stdoutmetric/config.go

@@ -20,7 +20,6 @@ import (
 	"go.opentelemetry.io/otel/internal/global"
 	"go.opentelemetry.io/otel/sdk/metric"
 	"go.opentelemetry.io/otel/sdk/metric/aggregation"
-	"go.opentelemetry.io/otel/sdk/metric/view"
 )
 
 // config contains options for the exporter.
@@ -101,7 +100,7 @@ func (t temporalitySelectorOption) apply(c config) config {
 // instrument.
 func WithAggregationSelector(selector metric.AggregationSelector) Option {
 	// Deep copy and validate before using.
-	wrapped := func(ik view.InstrumentKind) aggregation.Aggregation {
+	wrapped := func(ik metric.InstrumentKind) aggregation.Aggregation {
 		a := selector(ik)
 		cpA := a.Copy()
 		if err := cpA.Err(); err != nil {

exporters/stdout/stdoutmetric/exporter.go

@@ -22,7 +22,6 @@ import (
 	"go.opentelemetry.io/otel/sdk/metric"
 	"go.opentelemetry.io/otel/sdk/metric/aggregation"
 	"go.opentelemetry.io/otel/sdk/metric/metricdata"
-	"go.opentelemetry.io/otel/sdk/metric/view"
 )
 
 // exporter is an OpenTelemetry metric exporter.
@@ -49,11 +48,11 @@ func New(options ...Option) (metric.Exporter, error) {
 	return exp, nil
 }
 
-func (e *exporter) Temporality(k view.InstrumentKind) metricdata.Temporality {
+func (e *exporter) Temporality(k metric.InstrumentKind) metricdata.Temporality {
 	return e.temporalitySelector(k)
 }
 
-func (e *exporter) Aggregation(k view.InstrumentKind) aggregation.Aggregation {
+func (e *exporter) Aggregation(k metric.InstrumentKind) aggregation.Aggregation {
 	return e.aggregationSelector(k)
 }