Flatten sdk/metric/aggregation into sdk/metric (#4435)

* Deprecate the aggregation pkg

* Decouple the internal/aggregate from aggregation pkg

* Add Aggregation to the metric pkg

* Do not use sdk/metric/aggregation in stdoutmetric exporter

* Update all generated templates

* Update prom exporter

* Fix view example

* Add changes to changelog

* Update CHANGELOG.md

Co-authored-by: Robert Pająk <pellared@hotmail.com>

* Rename Sum to AggregationSum

* Fix comments

* Centralize validation of aggregation in pipeline

* Remove validation of agg in manual_reader selector opt

* Fix merge

---------

Co-authored-by: Robert Pająk <pellared@hotmail.com>

CHANGELOG.md

@@ -24,6 +24,7 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 - Accept 201 to 299 HTTP status as success in `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp` and `go.opentelemetry.io/otel/exporters/otlp/otlptrace/otlptracehttp`. (#4365)
 - Document the `Temporality` and `Aggregation` methods of the `"go.opentelemetry.io/otel/sdk/metric".Exporter"` need to be concurrent safe. (#4381)
 - Expand the set of units supported by the prometheus exporter, and don't add unit suffixes if they are already present in `go.opentelemetry.op/otel/exporters/prometheus` (#4374)
+- Move the `Aggregation` interface and its implementations from `go.opentelemetry.io/otel/sdk/metric/aggregation` to `go.opentelemetry.io/otel/sdk/metric`. (#4435)
 - The exporters in `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc` and `go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp` support the `OTEL_EXPORTER_OTLP_METRICS_DEFAULT_HISTOGRAM_AGGREGATION` environment variable. (#4437)
 
 ### Changed
@@ -89,6 +90,8 @@ This project adheres to [Semantic Versioning](https://semver.org/spec/v2.0.0.htm
 - The `go.opentelemetry.io/otel/exporters/otlp/otlptrace/internal/otlpconfig` package is deprecated. (#4425)
 - The `go.opentelemetry.io/otel/exporters/otlp/otlptrace/internal/otlptracetest` package is deprecated. (#4425)
 - The `go.opentelemetry.io/otel/exporters/otlp/otlptrace/internal/retry` package is deprecated. (#4425)
+- The `go.opentelemetry.io/otel/sdk/metric/aggregation` package is deprecated.
+  Use the aggregation types added to `go.opentelemetry.io/otel/sdk/metric` instead. (#4435)
 
 ## [1.16.0/0.39.0] 2023-05-18
 

example/view/main.go

@@ -29,7 +29,6 @@ import (
 	api "go.opentelemetry.io/otel/metric"
 	"go.opentelemetry.io/otel/sdk/instrumentation"
 	"go.opentelemetry.io/otel/sdk/metric"
-	"go.opentelemetry.io/otel/sdk/metric/aggregation"
 )
 
 const meterName = "github.com/open-telemetry/opentelemetry-go/example/view"
@@ -53,7 +52,7 @@ func main() {
 			},
 			metric.Stream{
 				Name: "bar",
-				Aggregation: aggregation.ExplicitBucketHistogram{
+				Aggregation: metric.AggregationExplicitBucketHistogram{
 					Boundaries: []float64{64, 128, 256, 512, 1024, 2048, 4096},
 				},
 			},

exporters/otlp/otlpmetric/internal/client.go

@@ -18,7 +18,6 @@ import (
 	"context"
 
 	"go.opentelemetry.io/otel/sdk/metric"
-	"go.opentelemetry.io/otel/sdk/metric/aggregation"
 	"go.opentelemetry.io/otel/sdk/metric/metricdata"
 	mpb "go.opentelemetry.io/proto/otlp/metrics/v1"
 )
@@ -29,7 +28,7 @@ type Client interface {
 	Temporality(metric.InstrumentKind) metricdata.Temporality
 
 	// Aggregation returns the Aggregation to use for an instrument kind.
-	Aggregation(metric.InstrumentKind) aggregation.Aggregation
+	Aggregation(metric.InstrumentKind) metric.Aggregation
 
 	// UploadMetrics transmits metric data to an OTLP receiver.
 	//

exporters/otlp/otlpmetric/internal/exporter.go

@@ -25,7 +25,6 @@ import (
 
 	"go.opentelemetry.io/otel/exporters/otlp/otlpmetric/internal/transform" // nolint: staticcheck  // Atomic deprecation.
 	"go.opentelemetry.io/otel/sdk/metric"
-	"go.opentelemetry.io/otel/sdk/metric/aggregation"
 	"go.opentelemetry.io/otel/sdk/metric/metricdata"
 	mpb "go.opentelemetry.io/proto/otlp/metrics/v1"
 )
@@ -47,7 +46,7 @@ func (e *Exporter) Temporality(k metric.InstrumentKind) metricdata.Temporality {
 }
 
 // Aggregation returns the Aggregation to use for an instrument kind.
-func (e *Exporter) Aggregation(k metric.InstrumentKind) aggregation.Aggregation {
+func (e *Exporter) Aggregation(k metric.InstrumentKind) metric.Aggregation {
 	e.clientMu.Lock()
 	defer e.clientMu.Unlock()
 	return e.client.Aggregation(k)
@@ -120,7 +119,7 @@ func (c shutdownClient) Temporality(k metric.InstrumentKind) metricdata.Temporal
 	return c.temporalitySelector(k)
 }
 
-func (c shutdownClient) Aggregation(k metric.InstrumentKind) aggregation.Aggregation {
+func (c shutdownClient) Aggregation(k metric.InstrumentKind) metric.Aggregation {
 	return c.aggregationSelector(k)
 }
 

exporters/otlp/otlpmetric/internal/exporter_test.go

@@ -22,7 +22,6 @@ import (
 	"github.com/stretchr/testify/assert"
 
 	"go.opentelemetry.io/otel/sdk/metric"
-	"go.opentelemetry.io/otel/sdk/metric/aggregation"
 	"go.opentelemetry.io/otel/sdk/metric/metricdata"
 	mpb "go.opentelemetry.io/proto/otlp/metrics/v1"
 )
@@ -37,7 +36,7 @@ func (c *client) Temporality(k metric.InstrumentKind) metricdata.Temporality {
 	return metric.DefaultTemporalitySelector(k)
 }
 
-func (c *client) Aggregation(k metric.InstrumentKind) aggregation.Aggregation {
+func (c *client) Aggregation(k metric.InstrumentKind) metric.Aggregation {
 	return metric.DefaultAggregationSelector(k)
 }
 

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

@@ -33,9 +33,7 @@ import (
 	"go.opentelemetry.io/otel/exporters/otlp/internal"                       // nolint: staticcheck  // Synchronous deprecation.
 	"go.opentelemetry.io/otel/exporters/otlp/internal/retry"                 // nolint: staticcheck  // Synchronous deprecation.
 	ominternal "go.opentelemetry.io/otel/exporters/otlp/otlpmetric/internal" // nolint: staticcheck  // Atomic deprecation.
-	"go.opentelemetry.io/otel/internal/global"
 	"go.opentelemetry.io/otel/sdk/metric"
-	"go.opentelemetry.io/otel/sdk/metric/aggregation"
 )
 
 const (
@@ -340,23 +338,8 @@ func WithTemporalitySelector(selector metric.TemporalitySelector) GenericOption
 }
 
 func WithAggregationSelector(selector metric.AggregationSelector) GenericOption {
-	// Deep copy and validate before using.
-	wrapped := func(ik metric.InstrumentKind) aggregation.Aggregation {
-		a := selector(ik)
-		cpA := a.Copy()
-		if err := cpA.Err(); err != nil {
-			cpA = metric.DefaultAggregationSelector(ik)
-			global.Error(
-				err, "using default aggregation instead",
-				"aggregation", a,
-				"replacement", cpA,
-			)
-		}
-		return cpA
-	}
-
 	return newGenericOption(func(cfg Config) Config {
-		cfg.Metrics.AggregationSelector = wrapped
+		cfg.Metrics.AggregationSelector = selector
 		return cfg
 	})
 }

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

@@ -24,7 +24,6 @@ import (
 	"go.opentelemetry.io/otel/exporters/otlp/internal/envconfig" // nolint: staticcheck  // Synchronous deprecation.
 	"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"
 )
 
@@ -415,7 +414,7 @@ func TestConfigs(t *testing.T) {
 				// all" was set.
 				var undefinedKind metric.InstrumentKind
 				got := c.Metrics.AggregationSelector
-				assert.Equal(t, aggregation.Drop{}, got(undefinedKind))
+				assert.Equal(t, metric.AggregationDrop{}, got(undefinedKind))
 			},
 		},
 	}
@@ -441,8 +440,8 @@ func TestConfigs(t *testing.T) {
 	}
 }
 
-func dropSelector(metric.InstrumentKind) aggregation.Aggregation {
-	return aggregation.Drop{}
+func dropSelector(metric.InstrumentKind) metric.Aggregation {
+	return metric.AggregationDrop{}
 }
 
 func deltaSelector(metric.InstrumentKind) metricdata.Temporality {

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

@@ -22,7 +22,6 @@ import (
 	"go.opentelemetry.io/otel/exporters/otlp/internal"                       // nolint: staticcheck  // Synchronous deprecation.
 	ominternal "go.opentelemetry.io/otel/exporters/otlp/otlpmetric/internal" // nolint: staticcheck  // Atomic deprecation.
 	"go.opentelemetry.io/otel/sdk/metric"
-	"go.opentelemetry.io/otel/sdk/metric/aggregation"
 	"go.opentelemetry.io/otel/sdk/metric/metricdata"
 	cpb "go.opentelemetry.io/proto/otlp/collector/metrics/v1"
 	mpb "go.opentelemetry.io/proto/otlp/metrics/v1"
@@ -37,7 +36,7 @@ func (c *client) Temporality(k metric.InstrumentKind) metricdata.Temporality {
 	return metric.DefaultTemporalitySelector(k)
 }
 
-func (c *client) Aggregation(k metric.InstrumentKind) aggregation.Aggregation {
+func (c *client) Aggregation(k metric.InstrumentKind) metric.Aggregation {
 	return metric.DefaultAggregationSelector(k)
 }
 

exporters/otlp/otlpmetric/otlpmetricgrpc/client_test.go

@@ -30,7 +30,6 @@ import (
 	"go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc/internal/oconf"
 	"go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc/internal/otest"
 	"go.opentelemetry.io/otel/sdk/metric"
-	"go.opentelemetry.io/otel/sdk/metric/aggregation"
 	"go.opentelemetry.io/otel/sdk/metric/metricdata"
 )
 
@@ -137,7 +136,7 @@ type clientShim struct {
 func (clientShim) Temporality(metric.InstrumentKind) metricdata.Temporality {
 	return metricdata.CumulativeTemporality
 }
-func (clientShim) Aggregation(metric.InstrumentKind) aggregation.Aggregation {
+func (clientShim) Aggregation(metric.InstrumentKind) metric.Aggregation {
 	return nil
 }
 func (clientShim) ForceFlush(ctx context.Context) error {

exporters/otlp/otlpmetric/otlpmetricgrpc/exporter.go

@@ -23,7 +23,6 @@ import (
 	"go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc/internal/transform"
 	"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/metricdata"
 	metricpb "go.opentelemetry.io/proto/otlp/metrics/v1"
 )
@@ -70,7 +69,7 @@ func (e *Exporter) Temporality(k metric.InstrumentKind) metricdata.Temporality {
 }
 
 // Aggregation returns the Aggregation to use for an instrument kind.
-func (e *Exporter) Aggregation(k metric.InstrumentKind) aggregation.Aggregation {
+func (e *Exporter) Aggregation(k metric.InstrumentKind) metric.Aggregation {
 	return e.aggregationSelector(k)
 }
 

exporters/otlp/otlpmetric/otlpmetricgrpc/internal/oconf/envconfig.go

@@ -29,7 +29,6 @@ import (
 	"go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc/internal/envconfig"
 	"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/metricdata"
 )
 
@@ -204,9 +203,9 @@ func withEnvAggPreference(n string, fn func(metric.AggregationSelector)) func(e
 			case "explicit_bucket_histogram":
 				fn(metric.DefaultAggregationSelector)
 			case "base2_exponential_bucket_histogram":
-				fn(func(kind metric.InstrumentKind) aggregation.Aggregation {
+				fn(func(kind metric.InstrumentKind) metric.Aggregation {
 					if kind == metric.InstrumentKindHistogram {
-						return aggregation.Base2ExponentialHistogram{
+						return metric.AggregationBase2ExponentialHistogram{
 							MaxSize:  160,
 							MaxScale: 20,
 							NoMinMax: false,

exporters/otlp/otlpmetric/otlpmetricgrpc/internal/oconf/envconfig_test.go

@@ -24,7 +24,6 @@ import (
 	"github.com/stretchr/testify/require"
 
 	"go.opentelemetry.io/otel/sdk/metric"
-	"go.opentelemetry.io/otel/sdk/metric/aggregation"
 	"go.opentelemetry.io/otel/sdk/metric/metricdata"
 )
 
@@ -111,7 +110,7 @@ func TestWithEnvAggPreference(t *testing.T) {
 	tests := []struct {
 		name     string
 		envValue string
-		want     map[metric.InstrumentKind]aggregation.Aggregation
+		want     map[metric.InstrumentKind]metric.Aggregation
 	}{
 		{
 			name:     "default do not set the selector",
@@ -124,7 +123,7 @@ func TestWithEnvAggPreference(t *testing.T) {
 		{
 			name:     "explicit_bucket_histogram",
 			envValue: "explicit_bucket_histogram",
-			want: map[metric.InstrumentKind]aggregation.Aggregation{
+			want: map[metric.InstrumentKind]metric.Aggregation{
 				metric.InstrumentKindCounter:                 metric.DefaultAggregationSelector(metric.InstrumentKindCounter),
 				metric.InstrumentKindHistogram:               metric.DefaultAggregationSelector(metric.InstrumentKindHistogram),
 				metric.InstrumentKindUpDownCounter:           metric.DefaultAggregationSelector(metric.InstrumentKindUpDownCounter),
@@ -136,9 +135,9 @@ func TestWithEnvAggPreference(t *testing.T) {
 		{
 			name:     "base2_exponential_bucket_histogram",
 			envValue: "base2_exponential_bucket_histogram",
-			want: map[metric.InstrumentKind]aggregation.Aggregation{
+			want: map[metric.InstrumentKind]metric.Aggregation{
 				metric.InstrumentKindCounter: metric.DefaultAggregationSelector(metric.InstrumentKindCounter),
-				metric.InstrumentKindHistogram: aggregation.Base2ExponentialHistogram{
+				metric.InstrumentKindHistogram: metric.AggregationBase2ExponentialHistogram{
 					MaxSize:  160,
 					MaxScale: 20,
 					NoMinMax: false,

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

@@ -32,9 +32,7 @@ import (
 
 	"go.opentelemetry.io/otel/exporters/otlp/otlpmetric"
 	"go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc/internal/retry"
-	"go.opentelemetry.io/otel/internal/global"
 	"go.opentelemetry.io/otel/sdk/metric"
-	"go.opentelemetry.io/otel/sdk/metric/aggregation"
 )
 
 const (
@@ -354,23 +352,8 @@ func WithTemporalitySelector(selector metric.TemporalitySelector) GenericOption
 }
 
 func WithAggregationSelector(selector metric.AggregationSelector) GenericOption {
-	// Deep copy and validate before using.
-	wrapped := func(ik metric.InstrumentKind) aggregation.Aggregation {
-		a := selector(ik)
-		cpA := a.Copy()
-		if err := cpA.Err(); err != nil {
-			cpA = metric.DefaultAggregationSelector(ik)
-			global.Error(
-				err, "using default aggregation instead",
-				"aggregation", a,
-				"replacement", cpA,
-			)
-		}
-		return cpA
-	}
-
 	return newGenericOption(func(cfg Config) Config {
-		cfg.Metrics.AggregationSelector = wrapped
+		cfg.Metrics.AggregationSelector = selector
 		return cfg
 	})
 }

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

@@ -26,7 +26,6 @@ import (
 
 	"go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc/internal/envconfig"
 	"go.opentelemetry.io/otel/sdk/metric"
-	"go.opentelemetry.io/otel/sdk/metric/aggregation"
 	"go.opentelemetry.io/otel/sdk/metric/metricdata"
 )
 
@@ -417,7 +416,7 @@ func TestConfigs(t *testing.T) {
 				// all" was set.
 				var undefinedKind metric.InstrumentKind
 				got := c.Metrics.AggregationSelector
-				assert.Equal(t, aggregation.Drop{}, got(undefinedKind))
+				assert.Equal(t, metric.AggregationDrop{}, got(undefinedKind))
 			},
 		},
 	}
@@ -443,8 +442,8 @@ func TestConfigs(t *testing.T) {
 	}
 }
 
-func dropSelector(metric.InstrumentKind) aggregation.Aggregation {
-	return aggregation.Drop{}
+func dropSelector(metric.InstrumentKind) metric.Aggregation {
+	return metric.AggregationDrop{}
 }
 
 func deltaSelector(metric.InstrumentKind) metricdata.Temporality {

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

@@ -24,7 +24,6 @@ import (
 	"go.opentelemetry.io/otel"
 	"go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetricgrpc/internal"
 	"go.opentelemetry.io/otel/sdk/metric"
-	"go.opentelemetry.io/otel/sdk/metric/aggregation"
 	"go.opentelemetry.io/otel/sdk/metric/metricdata"
 	cpb "go.opentelemetry.io/proto/otlp/collector/metrics/v1"
 	mpb "go.opentelemetry.io/proto/otlp/metrics/v1"
@@ -39,7 +38,7 @@ func (c *client) Temporality(k metric.InstrumentKind) metricdata.Temporality {
 	return metric.DefaultTemporalitySelector(k)
 }
 
-func (c *client) Aggregation(k metric.InstrumentKind) aggregation.Aggregation {
+func (c *client) Aggregation(k metric.InstrumentKind) metric.Aggregation {
 	return metric.DefaultAggregationSelector(k)
 }
 

exporters/otlp/otlpmetric/otlpmetrichttp/client_test.go

@@ -30,7 +30,6 @@ import (
 	"go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp/internal/oconf"
 	"go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp/internal/otest"
 	"go.opentelemetry.io/otel/sdk/metric"
-	"go.opentelemetry.io/otel/sdk/metric/aggregation"
 	"go.opentelemetry.io/otel/sdk/metric/metricdata"
 )
 
@@ -41,7 +40,7 @@ type clientShim struct {
 func (clientShim) Temporality(metric.InstrumentKind) metricdata.Temporality {
 	return metricdata.CumulativeTemporality
 }
-func (clientShim) Aggregation(metric.InstrumentKind) aggregation.Aggregation {
+func (clientShim) Aggregation(metric.InstrumentKind) metric.Aggregation {
 	return nil
 }
 func (clientShim) ForceFlush(ctx context.Context) error {

exporters/otlp/otlpmetric/otlpmetrichttp/exporter.go

@@ -23,7 +23,6 @@ import (
 	"go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp/internal/transform"
 	"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/metricdata"
 	metricpb "go.opentelemetry.io/proto/otlp/metrics/v1"
 )
@@ -70,7 +69,7 @@ func (e *Exporter) Temporality(k metric.InstrumentKind) metricdata.Temporality {
 }
 
 // Aggregation returns the Aggregation to use for an instrument kind.
-func (e *Exporter) Aggregation(k metric.InstrumentKind) aggregation.Aggregation {
+func (e *Exporter) Aggregation(k metric.InstrumentKind) metric.Aggregation {
 	return e.aggregationSelector(k)
 }
 

exporters/otlp/otlpmetric/otlpmetrichttp/internal/oconf/envconfig.go

@@ -29,7 +29,6 @@ import (
 	"go.opentelemetry.io/otel/exporters/otlp/otlpmetric/otlpmetrichttp/internal/envconfig"
 	"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/metricdata"
 )
 
@@ -204,9 +203,9 @@ func withEnvAggPreference(n string, fn func(metric.AggregationSelector)) func(e
 			case "explicit_bucket_histogram":
 				fn(metric.DefaultAggregationSelector)
 			case "base2_exponential_bucket_histogram":
-				fn(func(kind metric.InstrumentKind) aggregation.Aggregation {
+				fn(func(kind metric.InstrumentKind) metric.Aggregation {
 					if kind == metric.InstrumentKindHistogram {
-						return aggregation.Base2ExponentialHistogram{
+						return metric.AggregationBase2ExponentialHistogram{
 							MaxSize:  160,
 							MaxScale: 20,
 							NoMinMax: false,