[chore] Bump all otel deps (#3241)

vendor/go.opentelemetry.io/otel/sdk/instrumentation/library.go

@@ -4,5 +4,6 @@
 package instrumentation // import "go.opentelemetry.io/otel/sdk/instrumentation"
 
 // Library represents the instrumentation library.
-// Deprecated: please use Scope instead.
+//
+// Deprecated: use [Scope] instead.
 type Library = Scope

vendor/go.opentelemetry.io/otel/sdk/internal/env/env.go

@@ -22,7 +22,7 @@ const (
 	BatchSpanProcessorMaxQueueSizeKey = "OTEL_BSP_MAX_QUEUE_SIZE"
 	// BatchSpanProcessorMaxExportBatchSizeKey is the maximum batch size (i.e.
 	// 512). Note: it must be less than or equal to
-	// EnvBatchSpanProcessorMaxQueueSize.
+	// BatchSpanProcessorMaxQueueSize.
 	BatchSpanProcessorMaxExportBatchSizeKey = "OTEL_BSP_MAX_EXPORT_BATCH_SIZE"
 
 	// AttributeValueLengthKey is the maximum allowed attribute value size.

vendor/go.opentelemetry.io/otel/sdk/internal/gen.go

@@ -1,18 +0,0 @@
-// Copyright The OpenTelemetry Authors
-// SPDX-License-Identifier: Apache-2.0
-
-package internal // import "go.opentelemetry.io/otel/sdk/internal"
-
-//go:generate gotmpl --body=../../internal/shared/matchers/expectation.go.tmpl "--data={}" --out=matchers/expectation.go
-//go:generate gotmpl --body=../../internal/shared/matchers/expecter.go.tmpl "--data={}" --out=matchers/expecter.go
-//go:generate gotmpl --body=../../internal/shared/matchers/temporal_matcher.go.tmpl "--data={}" --out=matchers/temporal_matcher.go
-
-//go:generate gotmpl --body=../../internal/shared/internaltest/alignment.go.tmpl "--data={}" --out=internaltest/alignment.go
-//go:generate gotmpl --body=../../internal/shared/internaltest/env.go.tmpl "--data={}" --out=internaltest/env.go
-//go:generate gotmpl --body=../../internal/shared/internaltest/env_test.go.tmpl "--data={}" --out=internaltest/env_test.go
-//go:generate gotmpl --body=../../internal/shared/internaltest/errors.go.tmpl "--data={}" --out=internaltest/errors.go
-//go:generate gotmpl --body=../../internal/shared/internaltest/harness.go.tmpl "--data={\"matchersImportPath\": \"go.opentelemetry.io/otel/sdk/internal/matchers\"}" --out=internaltest/harness.go
-//go:generate gotmpl --body=../../internal/shared/internaltest/text_map_carrier.go.tmpl "--data={}" --out=internaltest/text_map_carrier.go
-//go:generate gotmpl --body=../../internal/shared/internaltest/text_map_carrier_test.go.tmpl "--data={}" --out=internaltest/text_map_carrier_test.go
-//go:generate gotmpl --body=../../internal/shared/internaltest/text_map_propagator.go.tmpl "--data={}" --out=internaltest/text_map_propagator.go
-//go:generate gotmpl --body=../../internal/shared/internaltest/text_map_propagator_test.go.tmpl "--data={}" --out=internaltest/text_map_propagator_test.go

vendor/go.opentelemetry.io/otel/sdk/internal/internal.go

@@ -1,17 +0,0 @@
-// Copyright The OpenTelemetry Authors
-// SPDX-License-Identifier: Apache-2.0
-
-package internal // import "go.opentelemetry.io/otel/sdk/internal"
-
-import "time"
-
-// MonotonicEndTime returns the end time at present
-// but offset from start, monotonically.
-//
-// The monotonic clock is used in subtractions hence
-// the duration since start added back to start gives
-// end as a monotonic time.
-// See https://golang.org/pkg/time/#hdr-Monotonic_Clocks
-func MonotonicEndTime(start time.Time) time.Time {
-	return start.Add(time.Since(start))
-}

vendor/go.opentelemetry.io/otel/sdk/internal/x/README.md

@@ -0,0 +1,46 @@
+# Experimental Features
+
+The SDK contains features that have not yet stabilized in the OpenTelemetry specification.
+These features are added to the OpenTelemetry Go SDK prior to stabilization in the specification so that users can start experimenting with them and provide feedback.
+
+These feature may change in backwards incompatible ways as feedback is applied.
+See the [Compatibility and Stability](#compatibility-and-stability) section for more information.
+
+## Features
+
+- [Resource](#resource)
+
+### Resource
+
+[OpenTelemetry resource semantic conventions] include many attribute definitions that are defined as experimental.
+To have experimental semantic conventions be added by [resource detectors] set the `OTEL_GO_X_RESOURCE` environment variable.
+The value set must be the case-insensitive string of `"true"` to enable the feature.
+All other values are ignored.
+
+<!-- TODO: document what attributes are added by which detector -->
+
+[OpenTelemetry resource semantic conventions]: https://opentelemetry.io/docs/specs/semconv/resource/
+[resource detectors]: https://pkg.go.dev/go.opentelemetry.io/otel/sdk/resource#Detector
+
+#### Examples
+
+Enable experimental resource semantic conventions.
+
+```console
+export OTEL_GO_X_RESOURCE=true
+```
+
+Disable experimental resource semantic conventions.
+
+```console
+unset OTEL_GO_X_RESOURCE
+```
+
+## Compatibility and Stability
+
+Experimental features do not fall within the scope of the OpenTelemetry Go versioning and stability [policy](../../../VERSIONING.md).
+These features may be removed or modified in successive version releases, including patch versions.
+
+When an experimental feature is promoted to a stable feature, a migration path will be included in the changelog entry of the release.
+There is no guarantee that any environment variable feature flags that enabled the experimental feature will be supported by the stable version.
+If they are supported, they may be accompanied with a deprecation notice stating a timeline for the removal of that support.

vendor/go.opentelemetry.io/otel/sdk/internal/x/x.go

@@ -0,0 +1,66 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+// Package x contains support for OTel SDK experimental features.
+//
+// This package should only be used for features defined in the specification.
+// It should not be used for experiments or new project ideas.
+package x // import "go.opentelemetry.io/otel/sdk/internal/x"
+
+import (
+	"os"
+	"strings"
+)
+
+// Resource is an experimental feature flag that defines if resource detectors
+// should be included experimental semantic conventions.
+//
+// To enable this feature set the OTEL_GO_X_RESOURCE environment variable
+// to the case-insensitive string value of "true" (i.e. "True" and "TRUE"
+// will also enable this).
+var Resource = newFeature("RESOURCE", func(v string) (string, bool) {
+	if strings.ToLower(v) == "true" {
+		return v, true
+	}
+	return "", false
+})
+
+// Feature is an experimental feature control flag. It provides a uniform way
+// to interact with these feature flags and parse their values.
+type Feature[T any] struct {
+	key   string
+	parse func(v string) (T, bool)
+}
+
+func newFeature[T any](suffix string, parse func(string) (T, bool)) Feature[T] {
+	const envKeyRoot = "OTEL_GO_X_"
+	return Feature[T]{
+		key:   envKeyRoot + suffix,
+		parse: parse,
+	}
+}
+
+// Key returns the environment variable key that needs to be set to enable the
+// feature.
+func (f Feature[T]) Key() string { return f.key }
+
+// Lookup returns the user configured value for the feature and true if the
+// user has enabled the feature. Otherwise, if the feature is not enabled, a
+// zero-value and false are returned.
+func (f Feature[T]) Lookup() (v T, ok bool) {
+	// https://github.com/open-telemetry/opentelemetry-specification/blob/62effed618589a0bec416a87e559c0a9d96289bb/specification/configuration/sdk-environment-variables.md#parsing-empty-value
+	//
+	// > The SDK MUST interpret an empty value of an environment variable the
+	// > same way as when the variable is unset.
+	vRaw := os.Getenv(f.key)
+	if vRaw == "" {
+		return v, ok
+	}
+	return f.parse(vRaw)
+}
+
+// Enabled returns if the feature is enabled.
+func (f Feature[T]) Enabled() bool {
+	_, ok := f.Lookup()
+	return ok
+}

vendor/go.opentelemetry.io/otel/sdk/metric/README.md

@@ -0,0 +1,3 @@
+# Metric SDK
+
+[![PkgGoDev](https://pkg.go.dev/badge/go.opentelemetry.io/otel/sdk/metric)](https://pkg.go.dev/go.opentelemetry.io/otel/sdk/metric)

vendor/go.opentelemetry.io/otel/sdk/metric/aggregation.go

@@ -1,22 +1,12 @@
 // Copyright The OpenTelemetry Authors
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
+// SPDX-License-Identifier: Apache-2.0
 
 package metric // import "go.opentelemetry.io/otel/sdk/metric"
 
 import (
 	"errors"
 	"fmt"
+	"slices"
 )
 
 // errAgg is wrapped by misconfigured aggregations.
@@ -141,10 +131,8 @@ func (h AggregationExplicitBucketHistogram) err() error {
 
 // copy returns a deep copy of h.
 func (h AggregationExplicitBucketHistogram) copy() Aggregation {
-	b := make([]float64, len(h.Boundaries))
-	copy(b, h.Boundaries)
 	return AggregationExplicitBucketHistogram{
-		Boundaries: b,
+		Boundaries: slices.Clone(h.Boundaries),
 		NoMinMax:   h.NoMinMax,
 	}
 }

vendor/go.opentelemetry.io/otel/sdk/metric/cache.go

@@ -1,16 +1,5 @@
 // Copyright The OpenTelemetry Authors
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
+// SPDX-License-Identifier: Apache-2.0
 
 package metric // import "go.opentelemetry.io/otel/sdk/metric"
 

vendor/go.opentelemetry.io/otel/sdk/metric/config.go

@@ -1,16 +1,5 @@
 // Copyright The OpenTelemetry Authors
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
+// SPDX-License-Identifier: Apache-2.0
 
 package metric // import "go.opentelemetry.io/otel/sdk/metric"
 
@@ -133,7 +122,7 @@ func WithReader(r Reader) Option {
 	})
 }
 
-// WithView associates views a MeterProvider.
+// WithView associates views with a MeterProvider.
 //
 // Views are appended to existing ones in a MeterProvider if this option is
 // used multiple times.

vendor/go.opentelemetry.io/otel/sdk/metric/doc.go

@@ -1,16 +1,5 @@
 // Copyright The OpenTelemetry Authors
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
+// SPDX-License-Identifier: Apache-2.0
 
 // Package metric provides an implementation of the OpenTelemetry metrics SDK.
 //
@@ -42,6 +31,14 @@
 // is being run on. That way when multiple instances of the code are collected
 // at a single endpoint their origin is decipherable.
 //
+// To avoid leaking memory, the SDK returns the same instrument for calls to
+// create new instruments with the same Name, Unit, and Description.
+// Importantly, callbacks provided using metric.WithFloat64Callback or
+// metric.WithInt64Callback will only apply for the first instrument created
+// with a given Name, Unit, and Description. Instead, use
+// Meter.RegisterCallback and Registration.Unregister to add and remove
+// callbacks without leaking memory.
+//
 // See [go.opentelemetry.io/otel/metric] for more information about
 // the metric API.
 //

vendor/go.opentelemetry.io/otel/sdk/metric/env.go

@@ -1,16 +1,5 @@
 // Copyright The OpenTelemetry Authors
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
+// SPDX-License-Identifier: Apache-2.0
 
 package metric // import "go.opentelemetry.io/otel/sdk/metric"
 

vendor/go.opentelemetry.io/otel/sdk/metric/exemplar.go

@@ -1,22 +1,12 @@
 // Copyright The OpenTelemetry Authors
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
+// SPDX-License-Identifier: Apache-2.0
 
 package metric // import "go.opentelemetry.io/otel/sdk/metric"
 
 import (
 	"os"
 	"runtime"
+	"slices"
 
 	"go.opentelemetry.io/otel/sdk/metric/internal/exemplar"
 	"go.opentelemetry.io/otel/sdk/metric/internal/x"
@@ -29,68 +19,63 @@ import (
 // Note: This will only return non-nil values when the experimental exemplar
 // feature is enabled and the OTEL_METRICS_EXEMPLAR_FILTER environment variable
 // is not set to always_off.
-func reservoirFunc[N int64 | float64](agg Aggregation) func() exemplar.Reservoir[N] {
+func reservoirFunc[N int64 | float64](agg Aggregation) func() exemplar.FilteredReservoir[N] {
 	if !x.Exemplars.Enabled() {
 		return nil
 	}
-
-	// https://github.com/open-telemetry/opentelemetry-specification/blob/d4b241f451674e8f611bb589477680341006ad2b/specification/metrics/sdk.md#exemplar-defaults
-	resF := func() func() exemplar.Reservoir[N] {
-		// Explicit bucket histogram aggregation with more than 1 bucket will
-		// use AlignedHistogramBucketExemplarReservoir.
-		a, ok := agg.(AggregationExplicitBucketHistogram)
-		if ok && len(a.Boundaries) > 0 {
-			cp := make([]float64, len(a.Boundaries))
-			copy(cp, a.Boundaries)
-			return func() exemplar.Reservoir[N] {
-				bounds := cp
-				return exemplar.Histogram[N](bounds)
-			}
-		}
-
-		var n int
-		if a, ok := agg.(AggregationBase2ExponentialHistogram); ok {
-			// Base2 Exponential Histogram Aggregation SHOULD use a
-			// SimpleFixedSizeExemplarReservoir with a reservoir equal to the
-			// smaller of the maximum number of buckets configured on the
-			// aggregation or twenty (e.g. min(20, max_buckets)).
-			n = int(a.MaxSize)
-			if n > 20 {
-				n = 20
-			}
-		} else {
-			// https://github.com/open-telemetry/opentelemetry-specification/blob/e94af89e3d0c01de30127a0f423e912f6cda7bed/specification/metrics/sdk.md#simplefixedsizeexemplarreservoir
-			//   This Exemplar reservoir MAY take a configuration parameter for
-			//   the size of the reservoir. If no size configuration is
-			//   provided, the default size MAY be the number of possible
-			//   concurrent threads (e.g. number of CPUs) to help reduce
-			//   contention. Otherwise, a default size of 1 SHOULD be used.
-			n = runtime.NumCPU()
-			if n < 1 {
-				// Should never be the case, but be defensive.
-				n = 1
-			}
-		}
-
-		return func() exemplar.Reservoir[N] {
-			return exemplar.FixedSize[N](n)
-		}
-	}
-
 	// https://github.com/open-telemetry/opentelemetry-specification/blob/d4b241f451674e8f611bb589477680341006ad2b/specification/configuration/sdk-environment-variables.md#exemplar
 	const filterEnvKey = "OTEL_METRICS_EXEMPLAR_FILTER"
 
+	var filter exemplar.Filter
+
 	switch os.Getenv(filterEnvKey) {
 	case "always_on":
-		return resF()
+		filter = exemplar.AlwaysOnFilter
 	case "always_off":
-		return exemplar.Drop[N]
+		return exemplar.Drop
 	case "trace_based":
 		fallthrough
 	default:
-		newR := resF()
-		return func() exemplar.Reservoir[N] {
-			return exemplar.SampledFilter(newR())
+		filter = exemplar.SampledFilter
+	}
+
+	// https://github.com/open-telemetry/opentelemetry-specification/blob/d4b241f451674e8f611bb589477680341006ad2b/specification/metrics/sdk.md#exemplar-defaults
+	// Explicit bucket histogram aggregation with more than 1 bucket will
+	// use AlignedHistogramBucketExemplarReservoir.
+	a, ok := agg.(AggregationExplicitBucketHistogram)
+	if ok && len(a.Boundaries) > 0 {
+		cp := slices.Clone(a.Boundaries)
+		return func() exemplar.FilteredReservoir[N] {
+			bounds := cp
+			return exemplar.NewFilteredReservoir[N](filter, exemplar.Histogram(bounds))
 		}
 	}
+
+	var n int
+	if a, ok := agg.(AggregationBase2ExponentialHistogram); ok {
+		// Base2 Exponential Histogram Aggregation SHOULD use a
+		// SimpleFixedSizeExemplarReservoir with a reservoir equal to the
+		// smaller of the maximum number of buckets configured on the
+		// aggregation or twenty (e.g. min(20, max_buckets)).
+		n = int(a.MaxSize)
+		if n > 20 {
+			n = 20
+		}
+	} else {
+		// https://github.com/open-telemetry/opentelemetry-specification/blob/e94af89e3d0c01de30127a0f423e912f6cda7bed/specification/metrics/sdk.md#simplefixedsizeexemplarreservoir
+		//   This Exemplar reservoir MAY take a configuration parameter for
+		//   the size of the reservoir. If no size configuration is
+		//   provided, the default size MAY be the number of possible
+		//   concurrent threads (e.g. number of CPUs) to help reduce
+		//   contention. Otherwise, a default size of 1 SHOULD be used.
+		n = runtime.NumCPU()
+		if n < 1 {
+			// Should never be the case, but be defensive.
+			n = 1
+		}
+	}
+
+	return func() exemplar.FilteredReservoir[N] {
+		return exemplar.NewFilteredReservoir[N](filter, exemplar.FixedSize(n))
+	}
 }

vendor/go.opentelemetry.io/otel/sdk/metric/exporter.go

@@ -1,16 +1,5 @@
 // Copyright The OpenTelemetry Authors
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
+// SPDX-License-Identifier: Apache-2.0
 
 package metric // import "go.opentelemetry.io/otel/sdk/metric"
 

vendor/go.opentelemetry.io/otel/sdk/metric/instrument.go

@@ -1,16 +1,5 @@
 // Copyright The OpenTelemetry Authors
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
+// SPDX-License-Identifier: Apache-2.0
 
 //go:generate stringer -type=InstrumentKind -trimprefix=InstrumentKind
 
@@ -29,10 +18,7 @@ import (
 	"go.opentelemetry.io/otel/sdk/metric/internal/aggregate"
 )
 
-var (
-	zeroInstrumentKind InstrumentKind
-	zeroScope          instrumentation.Scope
-)
+var zeroScope instrumentation.Scope
 
 // InstrumentKind is the identifier of a group of instruments that all
 // performing the same function.
@@ -41,28 +27,32 @@ type InstrumentKind uint8
 const (
 	// instrumentKindUndefined is an undefined instrument kind, it should not
 	// be used by any initialized type.
-	instrumentKindUndefined InstrumentKind = iota // nolint:deadcode,varcheck,unused
+	instrumentKindUndefined InstrumentKind = 0 // nolint:deadcode,varcheck,unused
 	// InstrumentKindCounter identifies a group of instruments that record
 	// increasing values synchronously with the code path they are measuring.
-	InstrumentKindCounter
+	InstrumentKindCounter InstrumentKind = 1
 	// InstrumentKindUpDownCounter identifies a group of instruments that
 	// record increasing and decreasing values synchronously with the code path
 	// they are measuring.
-	InstrumentKindUpDownCounter
+	InstrumentKindUpDownCounter InstrumentKind = 2
 	// InstrumentKindHistogram identifies a group of instruments that record a
 	// distribution of values synchronously with the code path they are
 	// measuring.
-	InstrumentKindHistogram
+	InstrumentKindHistogram InstrumentKind = 3
 	// InstrumentKindObservableCounter identifies a group of instruments that
 	// record increasing values in an asynchronous callback.
-	InstrumentKindObservableCounter
+	InstrumentKindObservableCounter InstrumentKind = 4
 	// InstrumentKindObservableUpDownCounter identifies a group of instruments
 	// that record increasing and decreasing values in an asynchronous
 	// callback.
-	InstrumentKindObservableUpDownCounter
+	InstrumentKindObservableUpDownCounter InstrumentKind = 5
 	// InstrumentKindObservableGauge identifies a group of instruments that
 	// record current values in an asynchronous callback.
-	InstrumentKindObservableGauge
+	InstrumentKindObservableGauge InstrumentKind = 6
+	// InstrumentKindGauge identifies a group of instruments that record
+	// instantaneous values synchronously with the code path they are
+	// measuring.
+	InstrumentKindGauge InstrumentKind = 7
 )
 
 type nonComparable [0]func() // nolint: unused  // This is indeed used.
@@ -84,11 +74,11 @@ type Instrument struct {
 	nonComparable // nolint: unused
 }
 
-// empty returns if all fields of i are their zero-value.
-func (i Instrument) empty() bool {
+// IsEmpty returns if all Instrument fields are their zero-value.
+func (i Instrument) IsEmpty() bool {
 	return i.Name == "" &&
 		i.Description == "" &&
-		i.Kind == zeroInstrumentKind &&
+		i.Kind == instrumentKindUndefined &&
 		i.Unit == "" &&
 		i.Scope == zeroScope
 }
@@ -119,7 +109,7 @@ func (i Instrument) matchesDescription(other Instrument) bool {
 // matchesKind returns true if the Kind of i is its zero-value or it equals the
 // Kind of other, otherwise false.
 func (i Instrument) matchesKind(other Instrument) bool {
-	return i.Kind == zeroInstrumentKind || i.Kind == other.Kind
+	return i.Kind == instrumentKindUndefined || i.Kind == other.Kind
 }
 
 // matchesUnit returns true if the Unit of i is its zero-value or it equals the
@@ -186,12 +176,14 @@ type int64Inst struct {
 	embedded.Int64Counter
 	embedded.Int64UpDownCounter
 	embedded.Int64Histogram
+	embedded.Int64Gauge
 }
 
 var (
 	_ metric.Int64Counter       = (*int64Inst)(nil)
 	_ metric.Int64UpDownCounter = (*int64Inst)(nil)
 	_ metric.Int64Histogram     = (*int64Inst)(nil)
+	_ metric.Int64Gauge         = (*int64Inst)(nil)
 )
 
 func (i *int64Inst) Add(ctx context.Context, val int64, opts ...metric.AddOption) {
@@ -216,12 +208,14 @@ type float64Inst struct {
 	embedded.Float64Counter
 	embedded.Float64UpDownCounter
 	embedded.Float64Histogram
+	embedded.Float64Gauge
 }
 
 var (
 	_ metric.Float64Counter       = (*float64Inst)(nil)
 	_ metric.Float64UpDownCounter = (*float64Inst)(nil)
 	_ metric.Float64Histogram     = (*float64Inst)(nil)
+	_ metric.Float64Gauge         = (*float64Inst)(nil)
 )
 
 func (i *float64Inst) Add(ctx context.Context, val float64, opts ...metric.AddOption) {

vendor/go.opentelemetry.io/otel/sdk/metric/instrumentkind_string.go

@@ -15,11 +15,12 @@ func _() {
 	_ = x[InstrumentKindObservableCounter-4]
 	_ = x[InstrumentKindObservableUpDownCounter-5]
 	_ = x[InstrumentKindObservableGauge-6]
+	_ = x[InstrumentKindGauge-7]
 }
 
-const _InstrumentKind_name = "instrumentKindUndefinedCounterUpDownCounterHistogramObservableCounterObservableUpDownCounterObservableGauge"
+const _InstrumentKind_name = "instrumentKindUndefinedCounterUpDownCounterHistogramObservableCounterObservableUpDownCounterObservableGaugeGauge"
 
-var _InstrumentKind_index = [...]uint8{0, 23, 30, 43, 52, 69, 92, 107}
+var _InstrumentKind_index = [...]uint8{0, 23, 30, 43, 52, 69, 92, 107, 112}
 
 func (i InstrumentKind) String() string {
 	if i >= InstrumentKind(len(_InstrumentKind_index)-1) {

vendor/go.opentelemetry.io/otel/sdk/metric/internal/aggregate/aggregate.go

@@ -1,16 +1,5 @@
 // Copyright The OpenTelemetry Authors
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
+// SPDX-License-Identifier: Apache-2.0
 
 package aggregate // import "go.opentelemetry.io/otel/sdk/metric/internal/aggregate"
 
@@ -50,7 +39,7 @@ type Builder[N int64 | float64] struct {
 	//
 	// If this is not provided a default factory function that returns an
 	// exemplar.Drop reservoir will be used.
-	ReservoirFunc func() exemplar.Reservoir[N]
+	ReservoirFunc func() exemplar.FilteredReservoir[N]
 	// AggregationLimit is the cardinality limit of measurement attributes. Any
 	// measurement for new attributes once the limit has been reached will be
 	// aggregated into a single aggregate for the "otel.metric.overflow"
@@ -61,12 +50,12 @@ type Builder[N int64 | float64] struct {
 	AggregationLimit int
 }
 
-func (b Builder[N]) resFunc() func() exemplar.Reservoir[N] {
+func (b Builder[N]) resFunc() func() exemplar.FilteredReservoir[N] {
 	if b.ReservoirFunc != nil {
 		return b.ReservoirFunc
 	}
 
-	return exemplar.Drop[N]
+	return exemplar.Drop
 }
 
 type fltrMeasure[N int64 | float64] func(ctx context.Context, value N, fltrAttr attribute.Set, droppedAttr []attribute.KeyValue)
@@ -85,21 +74,26 @@ func (b Builder[N]) filter(f fltrMeasure[N]) Measure[N] {
 }
 
 // LastValue returns a last-value aggregate function input and output.
-//
-// The Builder.Temporality is ignored and delta is use always.
 func (b Builder[N]) LastValue() (Measure[N], ComputeAggregation) {
-	// Delta temporality is the only temporality that makes semantic sense for
-	// a last-value aggregate.
 	lv := newLastValue[N](b.AggregationLimit, b.resFunc())
+	switch b.Temporality {
+	case metricdata.DeltaTemporality:
+		return b.filter(lv.measure), lv.delta
+	default:
+		return b.filter(lv.measure), lv.cumulative
+	}
+}
 
-	return b.filter(lv.measure), func(dest *metricdata.Aggregation) int {
-		// Ignore if dest is not a metricdata.Gauge. The chance for memory
-		// reuse of the DataPoints is missed (better luck next time).
-		gData, _ := (*dest).(metricdata.Gauge[N])
-		lv.computeAggregation(&gData.DataPoints)
-		*dest = gData
-
-		return len(gData.DataPoints)
+// PrecomputedLastValue returns a last-value aggregate function input and
+// output. The aggregation returned from the returned ComputeAggregation
+// function will always only return values from the previous collection cycle.
+func (b Builder[N]) PrecomputedLastValue() (Measure[N], ComputeAggregation) {
+	lv := newPrecomputedLastValue[N](b.AggregationLimit, b.resFunc())
+	switch b.Temporality {
+	case metricdata.DeltaTemporality:
+		return b.filter(lv.measure), lv.delta
+	default:
+		return b.filter(lv.measure), lv.cumulative
 	}
 }
 

vendor/go.opentelemetry.io/otel/sdk/metric/internal/aggregate/doc.go

@@ -1,16 +1,5 @@
 // Copyright The OpenTelemetry Authors
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
+// SPDX-License-Identifier: Apache-2.0
 
 // Package aggregate provides aggregate types used compute aggregations and
 // cycle the state of metric measurements made by the SDK. These types and

vendor/go.opentelemetry.io/otel/sdk/metric/internal/aggregate/exemplar.go

@@ -0,0 +1,42 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package aggregate // import "go.opentelemetry.io/otel/sdk/metric/internal/aggregate"
+
+import (
+	"sync"
+
+	"go.opentelemetry.io/otel/sdk/metric/internal/exemplar"
+	"go.opentelemetry.io/otel/sdk/metric/metricdata"
+)
+
+var exemplarPool = sync.Pool{
+	New: func() any { return new([]exemplar.Exemplar) },
+}
+
+func collectExemplars[N int64 | float64](out *[]metricdata.Exemplar[N], f func(*[]exemplar.Exemplar)) {
+	dest := exemplarPool.Get().(*[]exemplar.Exemplar)
+	defer func() {
+		*dest = (*dest)[:0]
+		exemplarPool.Put(dest)
+	}()
+
+	*dest = reset(*dest, len(*out), cap(*out))
+
+	f(dest)
+
+	*out = reset(*out, len(*dest), cap(*dest))
+	for i, e := range *dest {
+		(*out)[i].FilteredAttributes = e.FilteredAttributes
+		(*out)[i].Time = e.Time
+		(*out)[i].SpanID = e.SpanID
+		(*out)[i].TraceID = e.TraceID
+
+		switch e.Value.Type() {
+		case exemplar.Int64ValueType:
+			(*out)[i].Value = N(e.Value.Int64())
+		case exemplar.Float64ValueType:
+			(*out)[i].Value = N(e.Value.Float64())
+		}
+	}
+}

vendor/go.opentelemetry.io/otel/sdk/metric/internal/aggregate/exponential_histogram.go

@@ -1,16 +1,5 @@
 // Copyright The OpenTelemetry Authors
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
+// SPDX-License-Identifier: Apache-2.0
 
 package aggregate // import "go.opentelemetry.io/otel/sdk/metric/internal/aggregate"
 
@@ -41,7 +30,8 @@ const (
 
 // expoHistogramDataPoint is a single data point in an exponential histogram.
 type expoHistogramDataPoint[N int64 | float64] struct {
-	res exemplar.Reservoir[N]
+	attrs attribute.Set
+	res   exemplar.FilteredReservoir[N]
 
 	count uint64
 	min   N
@@ -52,14 +42,14 @@ type expoHistogramDataPoint[N int64 | float64] struct {
 	noMinMax bool
 	noSum    bool
 
-	scale int
+	scale int32
 
 	posBuckets expoBuckets
 	negBuckets expoBuckets
 	zeroCount  uint64
 }
 
-func newExpoHistogramDataPoint[N int64 | float64](maxSize, maxScale int, noMinMax, noSum bool) *expoHistogramDataPoint[N] {
+func newExpoHistogramDataPoint[N int64 | float64](attrs attribute.Set, maxSize int, maxScale int32, noMinMax, noSum bool) *expoHistogramDataPoint[N] {
 	f := math.MaxFloat64
 	max := N(f) // if N is int64, max will overflow to -9223372036854775808
 	min := N(-f)
@@ -68,6 +58,7 @@ func newExpoHistogramDataPoint[N int64 | float64](maxSize, maxScale int, noMinMa
 		min = N(minInt64)
 	}
 	return &expoHistogramDataPoint[N]{
+		attrs:    attrs,
 		min:      max,
 		max:      min,
 		maxSize:  maxSize,
@@ -128,11 +119,13 @@ func (p *expoHistogramDataPoint[N]) record(v N) {
 }
 
 // getBin returns the bin v should be recorded into.
-func (p *expoHistogramDataPoint[N]) getBin(v float64) int {
-	frac, exp := math.Frexp(v)
+func (p *expoHistogramDataPoint[N]) getBin(v float64) int32 {
+	frac, expInt := math.Frexp(v)
+	// 11-bit exponential.
+	exp := int32(expInt) // nolint: gosec
 	if p.scale <= 0 {
 		// Because of the choice of fraction is always 1 power of two higher than we want.
-		correction := 1
+		var correction int32 = 1
 		if frac == .5 {
 			// If v is an exact power of two the frac will be .5 and the exp
 			// will be one higher than we want.
@@ -140,7 +133,7 @@ func (p *expoHistogramDataPoint[N]) getBin(v float64) int {
 		}
 		return (exp - correction) >> (-p.scale)
 	}
-	return exp<<p.scale + int(math.Log(frac)*scaleFactors[p.scale]) - 1
+	return exp<<p.scale + int32(math.Log(frac)*scaleFactors[p.scale]) - 1
 }
 
 // scaleFactors are constants used in calculating the logarithm index. They are
@@ -171,20 +164,20 @@ var scaleFactors = [21]float64{
 
 // scaleChange returns the magnitude of the scale change needed to fit bin in
 // the bucket. If no scale change is needed 0 is returned.
-func (p *expoHistogramDataPoint[N]) scaleChange(bin, startBin, length int) int {
+func (p *expoHistogramDataPoint[N]) scaleChange(bin, startBin int32, length int) int32 {
 	if length == 0 {
 		// No need to rescale if there are no buckets.
 		return 0
 	}
 
-	low := startBin
-	high := bin
+	low := int(startBin)
+	high := int(bin)
 	if startBin >= bin {
-		low = bin
-		high = startBin + length - 1
+		low = int(bin)
+		high = int(startBin) + length - 1
 	}
 
-	count := 0
+	var count int32
 	for high-low >= p.maxSize {
 		low = low >> 1
 		high = high >> 1
@@ -198,39 +191,39 @@ func (p *expoHistogramDataPoint[N]) scaleChange(bin, startBin, length int) int {
 
 // expoBuckets is a set of buckets in an exponential histogram.
 type expoBuckets struct {
-	startBin int
+	startBin int32
 	counts   []uint64
 }
 
 // record increments the count for the given bin, and expands the buckets if needed.
 // Size changes must be done before calling this function.
-func (b *expoBuckets) record(bin int) {
+func (b *expoBuckets) record(bin int32) {
 	if len(b.counts) == 0 {
 		b.counts = []uint64{1}
 		b.startBin = bin
 		return
 	}
 
-	endBin := b.startBin + len(b.counts) - 1
+	endBin := int(b.startBin) + len(b.counts) - 1
 
 	// if the new bin is inside the current range
-	if bin >= b.startBin && bin <= endBin {
+	if bin >= b.startBin && int(bin) <= endBin {
 		b.counts[bin-b.startBin]++
 		return
 	}
 	// if the new bin is before the current start add spaces to the counts
 	if bin < b.startBin {
 		origLen := len(b.counts)
-		newLength := endBin - bin + 1
+		newLength := endBin - int(bin) + 1
 		shift := b.startBin - bin
 
 		if newLength > cap(b.counts) {
 			b.counts = append(b.counts, make([]uint64, newLength-len(b.counts))...)
 		}
 
-		copy(b.counts[shift:origLen+shift], b.counts[:])
+		copy(b.counts[shift:origLen+int(shift)], b.counts[:])
 		b.counts = b.counts[:newLength]
-		for i := 1; i < shift; i++ {
+		for i := 1; i < int(shift); i++ {
 			b.counts[i] = 0
 		}
 		b.startBin = bin
@@ -238,17 +231,17 @@ func (b *expoBuckets) record(bin int) {
 		return
 	}
 	// if the new is after the end add spaces to the end
-	if bin > endBin {
-		if bin-b.startBin < cap(b.counts) {
+	if int(bin) > endBin {
+		if int(bin-b.startBin) < cap(b.counts) {
 			b.counts = b.counts[:bin-b.startBin+1]
-			for i := endBin + 1 - b.startBin; i < len(b.counts); i++ {
+			for i := endBin + 1 - int(b.startBin); i < len(b.counts); i++ {
 				b.counts[i] = 0
 			}
 			b.counts[bin-b.startBin] = 1
 			return
 		}
 
-		end := make([]uint64, bin-b.startBin-len(b.counts)+1)
+		end := make([]uint64, int(bin-b.startBin)-len(b.counts)+1)
 		b.counts = append(b.counts, end...)
 		b.counts[bin-b.startBin] = 1
 	}
@@ -256,7 +249,7 @@ func (b *expoBuckets) record(bin int) {
 
 // downscale shrinks a bucket by a factor of 2*s. It will sum counts into the
 // correct lower resolution bucket.
-func (b *expoBuckets) downscale(delta int) {
+func (b *expoBuckets) downscale(delta int32) {
 	// Example
 	// delta = 2
 	// Original offset: -6
@@ -271,19 +264,19 @@ func (b *expoBuckets) downscale(delta int) {
 		return
 	}
 
-	steps := 1 << delta
+	steps := int32(1) << delta
 	offset := b.startBin % steps
 	offset = (offset + steps) % steps // to make offset positive
 	for i := 1; i < len(b.counts); i++ {
-		idx := i + offset
-		if idx%steps == 0 {
-			b.counts[idx/steps] = b.counts[i]
+		idx := i + int(offset)
+		if idx%int(steps) == 0 {
+			b.counts[idx/int(steps)] = b.counts[i]
 			continue
 		}
-		b.counts[idx/steps] += b.counts[i]
+		b.counts[idx/int(steps)] += b.counts[i]
 	}
 
-	lastIdx := (len(b.counts) - 1 + offset) / steps
+	lastIdx := (len(b.counts) - 1 + int(offset)) / int(steps)
 	b.counts = b.counts[:lastIdx+1]
 	b.startBin = b.startBin >> delta
 }
@@ -291,16 +284,16 @@ func (b *expoBuckets) downscale(delta int) {
 // newExponentialHistogram returns an Aggregator that summarizes a set of
 // measurements as an exponential histogram. Each histogram is scoped by attributes
 // and the aggregation cycle the measurements were made in.
-func newExponentialHistogram[N int64 | float64](maxSize, maxScale int32, noMinMax, noSum bool, limit int, r func() exemplar.Reservoir[N]) *expoHistogram[N] {
+func newExponentialHistogram[N int64 | float64](maxSize, maxScale int32, noMinMax, noSum bool, limit int, r func() exemplar.FilteredReservoir[N]) *expoHistogram[N] {
 	return &expoHistogram[N]{
 		noSum:    noSum,
 		noMinMax: noMinMax,
 		maxSize:  int(maxSize),
-		maxScale: int(maxScale),
+		maxScale: maxScale,
 
 		newRes: r,
 		limit:  newLimiter[*expoHistogramDataPoint[N]](limit),
-		values: make(map[attribute.Set]*expoHistogramDataPoint[N]),
+		values: make(map[attribute.Distinct]*expoHistogramDataPoint[N]),
 
 		start: now(),
 	}
@@ -312,11 +305,11 @@ type expoHistogram[N int64 | float64] struct {
 	noSum    bool
 	noMinMax bool
 	maxSize  int
-	maxScale int
+	maxScale int32
 
-	newRes   func() exemplar.Reservoir[N]
+	newRes   func() exemplar.FilteredReservoir[N]
 	limit    limiter[*expoHistogramDataPoint[N]]
-	values   map[attribute.Set]*expoHistogramDataPoint[N]
+	values   map[attribute.Distinct]*expoHistogramDataPoint[N]
 	valuesMu sync.Mutex
 
 	start time.Time
@@ -328,21 +321,19 @@ func (e *expoHistogram[N]) measure(ctx context.Context, value N, fltrAttr attrib
 		return
 	}
 
-	t := now()
-
 	e.valuesMu.Lock()
 	defer e.valuesMu.Unlock()
 
 	attr := e.limit.Attributes(fltrAttr, e.values)
-	v, ok := e.values[attr]
+	v, ok := e.values[attr.Equivalent()]
 	if !ok {
-		v = newExpoHistogramDataPoint[N](e.maxSize, e.maxScale, e.noMinMax, e.noSum)
+		v = newExpoHistogramDataPoint[N](attr, e.maxSize, e.maxScale, e.noMinMax, e.noSum)
 		v.res = e.newRes()
 
-		e.values[attr] = v
+		e.values[attr.Equivalent()] = v
 	}
 	v.record(value)
-	v.res.Offer(ctx, t, value, droppedAttr)
+	v.res.Offer(ctx, value, droppedAttr)
 }
 
 func (e *expoHistogram[N]) delta(dest *metricdata.Aggregation) int {
@@ -360,36 +351,38 @@ func (e *expoHistogram[N]) delta(dest *metricdata.Aggregation) int {
 	hDPts := reset(h.DataPoints, n, n)
 
 	var i int
-	for a, b := range e.values {
-		hDPts[i].Attributes = a
+	for _, val := range e.values {
+		hDPts[i].Attributes = val.attrs
 		hDPts[i].StartTime = e.start
 		hDPts[i].Time = t
-		hDPts[i].Count = b.count
-		hDPts[i].Scale = int32(b.scale)
-		hDPts[i].ZeroCount = b.zeroCount
+		hDPts[i].Count = val.count
+		hDPts[i].Scale = val.scale
+		hDPts[i].ZeroCount = val.zeroCount
 		hDPts[i].ZeroThreshold = 0.0
 
-		hDPts[i].PositiveBucket.Offset = int32(b.posBuckets.startBin)
-		hDPts[i].PositiveBucket.Counts = reset(hDPts[i].PositiveBucket.Counts, len(b.posBuckets.counts), len(b.posBuckets.counts))
-		copy(hDPts[i].PositiveBucket.Counts, b.posBuckets.counts)
+		hDPts[i].PositiveBucket.Offset = val.posBuckets.startBin
+		hDPts[i].PositiveBucket.Counts = reset(hDPts[i].PositiveBucket.Counts, len(val.posBuckets.counts), len(val.posBuckets.counts))
+		copy(hDPts[i].PositiveBucket.Counts, val.posBuckets.counts)
 
-		hDPts[i].NegativeBucket.Offset = int32(b.negBuckets.startBin)
-		hDPts[i].NegativeBucket.Counts = reset(hDPts[i].NegativeBucket.Counts, len(b.negBuckets.counts), len(b.negBuckets.counts))
-		copy(hDPts[i].NegativeBucket.Counts, b.negBuckets.counts)
+		hDPts[i].NegativeBucket.Offset = val.negBuckets.startBin
+		hDPts[i].NegativeBucket.Counts = reset(hDPts[i].NegativeBucket.Counts, len(val.negBuckets.counts), len(val.negBuckets.counts))
+		copy(hDPts[i].NegativeBucket.Counts, val.negBuckets.counts)
 
 		if !e.noSum {
-			hDPts[i].Sum = b.sum
+			hDPts[i].Sum = val.sum
 		}
 		if !e.noMinMax {
-			hDPts[i].Min = metricdata.NewExtrema(b.min)
-			hDPts[i].Max = metricdata.NewExtrema(b.max)
+			hDPts[i].Min = metricdata.NewExtrema(val.min)
+			hDPts[i].Max = metricdata.NewExtrema(val.max)
 		}
 
-		b.res.Collect(&hDPts[i].Exemplars)
+		collectExemplars(&hDPts[i].Exemplars, val.res.Collect)
 
-		delete(e.values, a)
 		i++
 	}
+	// Unused attribute sets do not report.
+	clear(e.values)
+
 	e.start = t
 	h.DataPoints = hDPts
 	*dest = h
@@ -411,32 +404,32 @@ func (e *expoHistogram[N]) cumulative(dest *metricdata.Aggregation) int {
 	hDPts := reset(h.DataPoints, n, n)
 
 	var i int
-	for a, b := range e.values {
-		hDPts[i].Attributes = a
+	for _, val := range e.values {
+		hDPts[i].Attributes = val.attrs
 		hDPts[i].StartTime = e.start
 		hDPts[i].Time = t
-		hDPts[i].Count = b.count
-		hDPts[i].Scale = int32(b.scale)
-		hDPts[i].ZeroCount = b.zeroCount
+		hDPts[i].Count = val.count
+		hDPts[i].Scale = val.scale
+		hDPts[i].ZeroCount = val.zeroCount
 		hDPts[i].ZeroThreshold = 0.0
 
-		hDPts[i].PositiveBucket.Offset = int32(b.posBuckets.startBin)
-		hDPts[i].PositiveBucket.Counts = reset(hDPts[i].PositiveBucket.Counts, len(b.posBuckets.counts), len(b.posBuckets.counts))
-		copy(hDPts[i].PositiveBucket.Counts, b.posBuckets.counts)
+		hDPts[i].PositiveBucket.Offset = val.posBuckets.startBin
+		hDPts[i].PositiveBucket.Counts = reset(hDPts[i].PositiveBucket.Counts, len(val.posBuckets.counts), len(val.posBuckets.counts))
+		copy(hDPts[i].PositiveBucket.Counts, val.posBuckets.counts)
 
-		hDPts[i].NegativeBucket.Offset = int32(b.negBuckets.startBin)
-		hDPts[i].NegativeBucket.Counts = reset(hDPts[i].NegativeBucket.Counts, len(b.negBuckets.counts), len(b.negBuckets.counts))
-		copy(hDPts[i].NegativeBucket.Counts, b.negBuckets.counts)
+		hDPts[i].NegativeBucket.Offset = val.negBuckets.startBin
+		hDPts[i].NegativeBucket.Counts = reset(hDPts[i].NegativeBucket.Counts, len(val.negBuckets.counts), len(val.negBuckets.counts))
+		copy(hDPts[i].NegativeBucket.Counts, val.negBuckets.counts)
 
 		if !e.noSum {
-			hDPts[i].Sum = b.sum
+			hDPts[i].Sum = val.sum
 		}
 		if !e.noMinMax {
-			hDPts[i].Min = metricdata.NewExtrema(b.min)
-			hDPts[i].Max = metricdata.NewExtrema(b.max)
+			hDPts[i].Min = metricdata.NewExtrema(val.min)
+			hDPts[i].Max = metricdata.NewExtrema(val.max)
 		}
 
-		b.res.Collect(&hDPts[i].Exemplars)
+		collectExemplars(&hDPts[i].Exemplars, val.res.Collect)
 
 		i++
 		// TODO (#3006): This will use an unbounded amount of memory if there

vendor/go.opentelemetry.io/otel/sdk/metric/internal/aggregate/histogram.go

@@ -1,21 +1,11 @@
 // Copyright The OpenTelemetry Authors
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
+// SPDX-License-Identifier: Apache-2.0
 
 package aggregate // import "go.opentelemetry.io/otel/sdk/metric/internal/aggregate"
 
 import (
 	"context"
+	"slices"
 	"sort"
 	"sync"
 	"time"
@@ -26,7 +16,8 @@ import (
 )
 
 type buckets[N int64 | float64] struct {
-	res exemplar.Reservoir[N]
+	attrs attribute.Set
+	res   exemplar.FilteredReservoir[N]
 
 	counts   []uint64
 	count    uint64
@@ -35,8 +26,8 @@ type buckets[N int64 | float64] struct {
 }
 
 // newBuckets returns buckets with n bins.
-func newBuckets[N int64 | float64](n int) *buckets[N] {
-	return &buckets[N]{counts: make([]uint64, n)}
+func newBuckets[N int64 | float64](attrs attribute.Set, n int) *buckets[N] {
+	return &buckets[N]{attrs: attrs, counts: make([]uint64, n)}
 }
 
 func (b *buckets[N]) sum(value N) { b.total += value }
@@ -57,26 +48,25 @@ type histValues[N int64 | float64] struct {
 	noSum  bool
 	bounds []float64
 
-	newRes   func() exemplar.Reservoir[N]
+	newRes   func() exemplar.FilteredReservoir[N]
 	limit    limiter[*buckets[N]]
-	values   map[attribute.Set]*buckets[N]
+	values   map[attribute.Distinct]*buckets[N]
 	valuesMu sync.Mutex
 }
 
-func newHistValues[N int64 | float64](bounds []float64, noSum bool, limit int, r func() exemplar.Reservoir[N]) *histValues[N] {
+func newHistValues[N int64 | float64](bounds []float64, noSum bool, limit int, r func() exemplar.FilteredReservoir[N]) *histValues[N] {
 	// The responsibility of keeping all buckets correctly associated with the
 	// passed boundaries is ultimately this type's responsibility. Make a copy
 	// here so we can always guarantee this. Or, in the case of failure, have
 	// complete control over the fix.
-	b := make([]float64, len(bounds))
-	copy(b, bounds)
-	sort.Float64s(b)
+	b := slices.Clone(bounds)
+	slices.Sort(b)
 	return &histValues[N]{
 		noSum:  noSum,
 		bounds: b,
 		newRes: r,
 		limit:  newLimiter[*buckets[N]](limit),
-		values: make(map[attribute.Set]*buckets[N]),
+		values: make(map[attribute.Distinct]*buckets[N]),
 	}
 }
 
@@ -90,13 +80,11 @@ func (s *histValues[N]) measure(ctx context.Context, value N, fltrAttr attribute
 	// (s.bounds[len(s.bounds)-1], +∞).
 	idx := sort.SearchFloat64s(s.bounds, float64(value))
 
-	t := now()
-
 	s.valuesMu.Lock()
 	defer s.valuesMu.Unlock()
 
 	attr := s.limit.Attributes(fltrAttr, s.values)
-	b, ok := s.values[attr]
+	b, ok := s.values[attr.Equivalent()]
 	if !ok {
 		// N+1 buckets. For example:
 		//
@@ -105,23 +93,23 @@ func (s *histValues[N]) measure(ctx context.Context, value N, fltrAttr attribute
 		// Then,
 		//
 		//   buckets = (-∞, 0], (0, 5.0], (5.0, 10.0], (10.0, +∞)
-		b = newBuckets[N](len(s.bounds) + 1)
+		b = newBuckets[N](attr, len(s.bounds)+1)
 		b.res = s.newRes()
 
 		// Ensure min and max are recorded values (not zero), for new buckets.
 		b.min, b.max = value, value
-		s.values[attr] = b
+		s.values[attr.Equivalent()] = b
 	}
 	b.bin(idx, value)
 	if !s.noSum {
 		b.sum(value)
 	}
-	b.res.Offer(ctx, t, value, droppedAttr)
+	b.res.Offer(ctx, value, droppedAttr)
 }
 
 // newHistogram returns an Aggregator that summarizes a set of measurements as
 // an histogram.
-func newHistogram[N int64 | float64](boundaries []float64, noMinMax, noSum bool, limit int, r func() exemplar.Reservoir[N]) *histogram[N] {
+func newHistogram[N int64 | float64](boundaries []float64, noMinMax, noSum bool, limit int, r func() exemplar.FilteredReservoir[N]) *histogram[N] {
 	return &histogram[N]{
 		histValues: newHistValues[N](boundaries, noSum, limit, r),
 		noMinMax:   noMinMax,
@@ -150,36 +138,35 @@ func (s *histogram[N]) delta(dest *metricdata.Aggregation) int {
 	defer s.valuesMu.Unlock()
 
 	// Do not allow modification of our copy of bounds.
-	bounds := make([]float64, len(s.bounds))
-	copy(bounds, s.bounds)
+	bounds := slices.Clone(s.bounds)
 
 	n := len(s.values)
 	hDPts := reset(h.DataPoints, n, n)
 
 	var i int
-	for a, b := range s.values {
-		hDPts[i].Attributes = a
+	for _, val := range s.values {
+		hDPts[i].Attributes = val.attrs
 		hDPts[i].StartTime = s.start
 		hDPts[i].Time = t
-		hDPts[i].Count = b.count
+		hDPts[i].Count = val.count
 		hDPts[i].Bounds = bounds
-		hDPts[i].BucketCounts = b.counts
+		hDPts[i].BucketCounts = val.counts
 
 		if !s.noSum {
-			hDPts[i].Sum = b.total
+			hDPts[i].Sum = val.total
 		}
 
 		if !s.noMinMax {
-			hDPts[i].Min = metricdata.NewExtrema(b.min)
-			hDPts[i].Max = metricdata.NewExtrema(b.max)
+			hDPts[i].Min = metricdata.NewExtrema(val.min)
+			hDPts[i].Max = metricdata.NewExtrema(val.max)
 		}
 
-		b.res.Collect(&hDPts[i].Exemplars)
+		collectExemplars(&hDPts[i].Exemplars, val.res.Collect)
 
-		// Unused attribute sets do not report.
-		delete(s.values, a)
 		i++
 	}
+	// Unused attribute sets do not report.
+	clear(s.values)
 	// The delta collection cycle resets.
 	s.start = t
 
@@ -201,39 +188,36 @@ func (s *histogram[N]) cumulative(dest *metricdata.Aggregation) int {
 	defer s.valuesMu.Unlock()
 
 	// Do not allow modification of our copy of bounds.
-	bounds := make([]float64, len(s.bounds))
-	copy(bounds, s.bounds)
+	bounds := slices.Clone(s.bounds)
 
 	n := len(s.values)
 	hDPts := reset(h.DataPoints, n, n)
 
 	var i int
-	for a, b := range s.values {
+	for _, val := range s.values {
+		hDPts[i].Attributes = val.attrs
+		hDPts[i].StartTime = s.start
+		hDPts[i].Time = t
+		hDPts[i].Count = val.count
+		hDPts[i].Bounds = bounds
+
 		// The HistogramDataPoint field values returned need to be copies of
 		// the buckets value as we will keep updating them.
 		//
 		// TODO (#3047): Making copies for bounds and counts incurs a large
 		// memory allocation footprint. Alternatives should be explored.
-		counts := make([]uint64, len(b.counts))
-		copy(counts, b.counts)
-
-		hDPts[i].Attributes = a
-		hDPts[i].StartTime = s.start
-		hDPts[i].Time = t
-		hDPts[i].Count = b.count
-		hDPts[i].Bounds = bounds
-		hDPts[i].BucketCounts = counts
+		hDPts[i].BucketCounts = slices.Clone(val.counts)
 
 		if !s.noSum {
-			hDPts[i].Sum = b.total
+			hDPts[i].Sum = val.total
 		}
 
 		if !s.noMinMax {
-			hDPts[i].Min = metricdata.NewExtrema(b.min)
-			hDPts[i].Max = metricdata.NewExtrema(b.max)
+			hDPts[i].Min = metricdata.NewExtrema(val.min)
+			hDPts[i].Max = metricdata.NewExtrema(val.max)
 		}
 
-		b.res.Collect(&hDPts[i].Exemplars)
+		collectExemplars(&hDPts[i].Exemplars, val.res.Collect)
 
 		i++
 		// TODO (#3006): This will use an unbounded amount of memory if there

vendor/go.opentelemetry.io/otel/sdk/metric/internal/aggregate/lastvalue.go

@@ -1,16 +1,5 @@
 // Copyright The OpenTelemetry Authors
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
+// SPDX-License-Identifier: Apache-2.0
 
 package aggregate // import "go.opentelemetry.io/otel/sdk/metric/internal/aggregate"
 
@@ -26,16 +15,17 @@ import (
 
 // datapoint is timestamped measurement data.
 type datapoint[N int64 | float64] struct {
-	timestamp time.Time
-	value     N
-	res       exemplar.Reservoir[N]
+	attrs attribute.Set
+	value N
+	res   exemplar.FilteredReservoir[N]
 }
 
-func newLastValue[N int64 | float64](limit int, r func() exemplar.Reservoir[N]) *lastValue[N] {
+func newLastValue[N int64 | float64](limit int, r func() exemplar.FilteredReservoir[N]) *lastValue[N] {
 	return &lastValue[N]{
 		newRes: r,
 		limit:  newLimiter[datapoint[N]](limit),
-		values: make(map[attribute.Set]datapoint[N]),
+		values: make(map[attribute.Distinct]datapoint[N]),
+		start:  now(),
 	}
 }
 
@@ -43,47 +33,130 @@ func newLastValue[N int64 | float64](limit int, r func() exemplar.Reservoir[N])
 type lastValue[N int64 | float64] struct {
 	sync.Mutex
 
-	newRes func() exemplar.Reservoir[N]
+	newRes func() exemplar.FilteredReservoir[N]
 	limit  limiter[datapoint[N]]
-	values map[attribute.Set]datapoint[N]
+	values map[attribute.Distinct]datapoint[N]
+	start  time.Time
 }
 
 func (s *lastValue[N]) measure(ctx context.Context, value N, fltrAttr attribute.Set, droppedAttr []attribute.KeyValue) {
-	t := now()
-
 	s.Lock()
 	defer s.Unlock()
 
 	attr := s.limit.Attributes(fltrAttr, s.values)
-	d, ok := s.values[attr]
+	d, ok := s.values[attr.Equivalent()]
 	if !ok {
 		d.res = s.newRes()
 	}
 
-	d.timestamp = t
+	d.attrs = attr
 	d.value = value
-	d.res.Offer(ctx, t, value, droppedAttr)
+	d.res.Offer(ctx, value, droppedAttr)
 
-	s.values[attr] = d
+	s.values[attr.Equivalent()] = d
 }
 
-func (s *lastValue[N]) computeAggregation(dest *[]metricdata.DataPoint[N]) {
+func (s *lastValue[N]) delta(dest *metricdata.Aggregation) int {
+	t := now()
+	// Ignore if dest is not a metricdata.Gauge. The chance for memory reuse of
+	// the DataPoints is missed (better luck next time).
+	gData, _ := (*dest).(metricdata.Gauge[N])
+
 	s.Lock()
 	defer s.Unlock()
 
+	n := s.copyDpts(&gData.DataPoints, t)
+	// Do not report stale values.
+	clear(s.values)
+	// Update start time for delta temporality.
+	s.start = t
+
+	*dest = gData
+
+	return n
+}
+
+func (s *lastValue[N]) cumulative(dest *metricdata.Aggregation) int {
+	t := now()
+	// Ignore if dest is not a metricdata.Gauge. The chance for memory reuse of
+	// the DataPoints is missed (better luck next time).
+	gData, _ := (*dest).(metricdata.Gauge[N])
+
+	s.Lock()
+	defer s.Unlock()
+
+	n := s.copyDpts(&gData.DataPoints, t)
+	// TODO (#3006): This will use an unbounded amount of memory if there
+	// are unbounded number of attribute sets being aggregated. Attribute
+	// sets that become "stale" need to be forgotten so this will not
+	// overload the system.
+	*dest = gData
+
+	return n
+}
+
+// copyDpts copies the datapoints held by s into dest. The number of datapoints
+// copied is returned.
+func (s *lastValue[N]) copyDpts(dest *[]metricdata.DataPoint[N], t time.Time) int {
 	n := len(s.values)
 	*dest = reset(*dest, n, n)
 
 	var i int
-	for a, v := range s.values {
-		(*dest)[i].Attributes = a
-		// The event time is the only meaningful timestamp, StartTime is
-		// ignored.
-		(*dest)[i].Time = v.timestamp
+	for _, v := range s.values {
+		(*dest)[i].Attributes = v.attrs
+		(*dest)[i].StartTime = s.start
+		(*dest)[i].Time = t
 		(*dest)[i].Value = v.value
-		v.res.Collect(&(*dest)[i].Exemplars)
-		// Do not report stale values.
-		delete(s.values, a)
+		collectExemplars(&(*dest)[i].Exemplars, v.res.Collect)
 		i++
 	}
+	return n
+}
+
+// newPrecomputedLastValue returns an aggregator that summarizes a set of
+// observations as the last one made.
+func newPrecomputedLastValue[N int64 | float64](limit int, r func() exemplar.FilteredReservoir[N]) *precomputedLastValue[N] {
+	return &precomputedLastValue[N]{lastValue: newLastValue[N](limit, r)}
+}
+
+// precomputedLastValue summarizes a set of observations as the last one made.
+type precomputedLastValue[N int64 | float64] struct {
+	*lastValue[N]
+}
+
+func (s *precomputedLastValue[N]) delta(dest *metricdata.Aggregation) int {
+	t := now()
+	// Ignore if dest is not a metricdata.Gauge. The chance for memory reuse of
+	// the DataPoints is missed (better luck next time).
+	gData, _ := (*dest).(metricdata.Gauge[N])
+
+	s.Lock()
+	defer s.Unlock()
+
+	n := s.copyDpts(&gData.DataPoints, t)
+	// Do not report stale values.
+	clear(s.values)
+	// Update start time for delta temporality.
+	s.start = t
+
+	*dest = gData
+
+	return n
+}
+
+func (s *precomputedLastValue[N]) cumulative(dest *metricdata.Aggregation) int {
+	t := now()
+	// Ignore if dest is not a metricdata.Gauge. The chance for memory reuse of
+	// the DataPoints is missed (better luck next time).
+	gData, _ := (*dest).(metricdata.Gauge[N])
+
+	s.Lock()
+	defer s.Unlock()
+
+	n := s.copyDpts(&gData.DataPoints, t)
+	// Do not report stale values.
+	clear(s.values)
+	*dest = gData
+
+	return n
 }

vendor/go.opentelemetry.io/otel/sdk/metric/internal/aggregate/limit.go

@@ -1,16 +1,5 @@
 // Copyright The OpenTelemetry Authors
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
+// SPDX-License-Identifier: Apache-2.0
 
 package aggregate // import "go.opentelemetry.io/otel/sdk/metric/internal/aggregate"
 
@@ -41,9 +30,9 @@ func newLimiter[V any](aggregation int) limiter[V] {
 // aggregation cardinality limit for the existing measurements. If it will,
 // overflowSet is returned. Otherwise, if it will not exceed the limit, or the
 // limit is not set (limit <= 0), attr is returned.
-func (l limiter[V]) Attributes(attrs attribute.Set, measurements map[attribute.Set]V) attribute.Set {
+func (l limiter[V]) Attributes(attrs attribute.Set, measurements map[attribute.Distinct]V) attribute.Set {
 	if l.aggLimit > 0 {
-		_, exists := measurements[attrs]
+		_, exists := measurements[attrs.Equivalent()]
 		if !exists && len(measurements) >= l.aggLimit-1 {
 			return overflowSet
 		}

vendor/go.opentelemetry.io/otel/sdk/metric/internal/aggregate/sum.go

@@ -1,16 +1,5 @@
 // Copyright The OpenTelemetry Authors
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
+// SPDX-License-Identifier: Apache-2.0
 
 package aggregate // import "go.opentelemetry.io/otel/sdk/metric/internal/aggregate"
 
@@ -25,48 +14,48 @@ import (
 )
 
 type sumValue[N int64 | float64] struct {
-	n   N
-	res exemplar.Reservoir[N]
+	n     N
+	res   exemplar.FilteredReservoir[N]
+	attrs attribute.Set
 }
 
 // valueMap is the storage for sums.
 type valueMap[N int64 | float64] struct {
 	sync.Mutex
-	newRes func() exemplar.Reservoir[N]
+	newRes func() exemplar.FilteredReservoir[N]
 	limit  limiter[sumValue[N]]
-	values map[attribute.Set]sumValue[N]
+	values map[attribute.Distinct]sumValue[N]
 }
 
-func newValueMap[N int64 | float64](limit int, r func() exemplar.Reservoir[N]) *valueMap[N] {
+func newValueMap[N int64 | float64](limit int, r func() exemplar.FilteredReservoir[N]) *valueMap[N] {
 	return &valueMap[N]{
 		newRes: r,
 		limit:  newLimiter[sumValue[N]](limit),
-		values: make(map[attribute.Set]sumValue[N]),
+		values: make(map[attribute.Distinct]sumValue[N]),
 	}
 }
 
 func (s *valueMap[N]) measure(ctx context.Context, value N, fltrAttr attribute.Set, droppedAttr []attribute.KeyValue) {
-	t := now()
-
 	s.Lock()
 	defer s.Unlock()
 
 	attr := s.limit.Attributes(fltrAttr, s.values)
-	v, ok := s.values[attr]
+	v, ok := s.values[attr.Equivalent()]
 	if !ok {
 		v.res = s.newRes()
 	}
 
+	v.attrs = attr
 	v.n += value
-	v.res.Offer(ctx, t, value, droppedAttr)
+	v.res.Offer(ctx, value, droppedAttr)
 
-	s.values[attr] = v
+	s.values[attr.Equivalent()] = v
 }
 
 // newSum returns an aggregator that summarizes a set of measurements as their
 // arithmetic sum. Each sum is scoped by attributes and the aggregation cycle
 // the measurements were made in.
-func newSum[N int64 | float64](monotonic bool, limit int, r func() exemplar.Reservoir[N]) *sum[N] {
+func newSum[N int64 | float64](monotonic bool, limit int, r func() exemplar.FilteredReservoir[N]) *sum[N] {
 	return &sum[N]{
 		valueMap:  newValueMap[N](limit, r),
 		monotonic: monotonic,
@@ -98,16 +87,16 @@ func (s *sum[N]) delta(dest *metricdata.Aggregation) int {
 	dPts := reset(sData.DataPoints, n, n)
 
 	var i int
-	for attr, val := range s.values {
-		dPts[i].Attributes = attr
+	for _, val := range s.values {
+		dPts[i].Attributes = val.attrs
 		dPts[i].StartTime = s.start
 		dPts[i].Time = t
 		dPts[i].Value = val.n
-		val.res.Collect(&dPts[i].Exemplars)
-		// Do not report stale values.
-		delete(s.values, attr)
+		collectExemplars(&dPts[i].Exemplars, val.res.Collect)
 		i++
 	}
+	// Do not report stale values.
+	clear(s.values)
 	// The delta collection cycle resets.
 	s.start = t
 
@@ -133,12 +122,12 @@ func (s *sum[N]) cumulative(dest *metricdata.Aggregation) int {
 	dPts := reset(sData.DataPoints, n, n)
 
 	var i int
-	for attr, value := range s.values {
-		dPts[i].Attributes = attr
+	for _, value := range s.values {
+		dPts[i].Attributes = value.attrs
 		dPts[i].StartTime = s.start
 		dPts[i].Time = t
 		dPts[i].Value = value.n
-		value.res.Collect(&dPts[i].Exemplars)
+		collectExemplars(&dPts[i].Exemplars, value.res.Collect)
 		// TODO (#3006): This will use an unbounded amount of memory if there
 		// are unbounded number of attribute sets being aggregated. Attribute
 		// sets that become "stale" need to be forgotten so this will not
@@ -155,7 +144,7 @@ func (s *sum[N]) cumulative(dest *metricdata.Aggregation) int {
 // newPrecomputedSum returns an aggregator that summarizes a set of
 // observatrions as their arithmetic sum. Each sum is scoped by attributes and
 // the aggregation cycle the measurements were made in.
-func newPrecomputedSum[N int64 | float64](monotonic bool, limit int, r func() exemplar.Reservoir[N]) *precomputedSum[N] {
+func newPrecomputedSum[N int64 | float64](monotonic bool, limit int, r func() exemplar.FilteredReservoir[N]) *precomputedSum[N] {
 	return &precomputedSum[N]{
 		valueMap:  newValueMap[N](limit, r),
 		monotonic: monotonic,
@@ -170,12 +159,12 @@ type precomputedSum[N int64 | float64] struct {
 	monotonic bool
 	start     time.Time
 
-	reported map[attribute.Set]N
+	reported map[attribute.Distinct]N
 }
 
 func (s *precomputedSum[N]) delta(dest *metricdata.Aggregation) int {
 	t := now()
-	newReported := make(map[attribute.Set]N)
+	newReported := make(map[attribute.Distinct]N)
 
 	// If *dest is not a metricdata.Sum, memory reuse is missed. In that case,
 	// use the zero-value sData and hope for better alignment next cycle.
@@ -190,21 +179,20 @@ func (s *precomputedSum[N]) delta(dest *metricdata.Aggregation) int {
 	dPts := reset(sData.DataPoints, n, n)
 
 	var i int
-	for attr, value := range s.values {
-		delta := value.n - s.reported[attr]
+	for key, value := range s.values {
+		delta := value.n - s.reported[key]
 
-		dPts[i].Attributes = attr
+		dPts[i].Attributes = value.attrs
 		dPts[i].StartTime = s.start
 		dPts[i].Time = t
 		dPts[i].Value = delta
-		value.res.Collect(&dPts[i].Exemplars)
+		collectExemplars(&dPts[i].Exemplars, value.res.Collect)
 
-		newReported[attr] = value.n
-		// Unused attribute sets do not report.
-		delete(s.values, attr)
+		newReported[key] = value.n
 		i++
 	}
-	// Unused attribute sets are forgotten.
+	// Unused attribute sets do not report.
+	clear(s.values)
 	s.reported = newReported
 	// The delta collection cycle resets.
 	s.start = t
@@ -231,17 +219,17 @@ func (s *precomputedSum[N]) cumulative(dest *metricdata.Aggregation) int {
 	dPts := reset(sData.DataPoints, n, n)
 
 	var i int
-	for attr, val := range s.values {
-		dPts[i].Attributes = attr
+	for _, val := range s.values {
+		dPts[i].Attributes = val.attrs
 		dPts[i].StartTime = s.start
 		dPts[i].Time = t
 		dPts[i].Value = val.n
-		val.res.Collect(&dPts[i].Exemplars)
+		collectExemplars(&dPts[i].Exemplars, val.res.Collect)
 
-		// Unused attribute sets do not report.
-		delete(s.values, attr)
 		i++
 	}
+	// Unused attribute sets do not report.
+	clear(s.values)
 
 	sData.DataPoints = dPts
 	*dest = sData

vendor/go.opentelemetry.io/otel/sdk/metric/internal/exemplar/doc.go

@@ -1,16 +1,5 @@
 // Copyright The OpenTelemetry Authors
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
+// SPDX-License-Identifier: Apache-2.0
 
 // Package exemplar provides an implementation of the OpenTelemetry exemplar
 // reservoir to be used in metric collection pipelines.

vendor/go.opentelemetry.io/otel/sdk/metric/internal/exemplar/drop.go

@@ -1,36 +1,23 @@
 // Copyright The OpenTelemetry Authors
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
+// SPDX-License-Identifier: Apache-2.0
 
 package exemplar // import "go.opentelemetry.io/otel/sdk/metric/internal/exemplar"
 
 import (
 	"context"
-	"time"
 
 	"go.opentelemetry.io/otel/attribute"
-	"go.opentelemetry.io/otel/sdk/metric/metricdata"
 )
 
-// Drop returns a [Reservoir] that drops all measurements it is offered.
-func Drop[N int64 | float64]() Reservoir[N] { return &dropRes[N]{} }
+// Drop returns a [FilteredReservoir] that drops all measurements it is offered.
+func Drop[N int64 | float64]() FilteredReservoir[N] { return &dropRes[N]{} }
 
 type dropRes[N int64 | float64] struct{}
 
 // Offer does nothing, all measurements offered will be dropped.
-func (r *dropRes[N]) Offer(context.Context, time.Time, N, []attribute.KeyValue) {}
+func (r *dropRes[N]) Offer(context.Context, N, []attribute.KeyValue) {}
 
 // Collect resets dest. No exemplars will ever be returned.
-func (r *dropRes[N]) Collect(dest *[]metricdata.Exemplar[N]) {
+func (r *dropRes[N]) Collect(dest *[]Exemplar) {
 	*dest = (*dest)[:0]
 }

vendor/go.opentelemetry.io/otel/sdk/metric/internal/exemplar/exemplar.go

@@ -0,0 +1,29 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package exemplar // import "go.opentelemetry.io/otel/sdk/metric/internal/exemplar"
+
+import (
+	"time"
+
+	"go.opentelemetry.io/otel/attribute"
+)
+
+// Exemplar is a measurement sampled from a timeseries providing a typical
+// example.
+type Exemplar struct {
+	// FilteredAttributes are the attributes recorded with the measurement but
+	// filtered out of the timeseries' aggregated data.
+	FilteredAttributes []attribute.KeyValue
+	// Time is the time when the measurement was recorded.
+	Time time.Time
+	// Value is the measured value.
+	Value Value
+	// SpanID is the ID of the span that was active during the measurement. If
+	// no span was active or the span was not sampled this will be empty.
+	SpanID []byte `json:",omitempty"`
+	// TraceID is the ID of the trace the active span belonged to during the
+	// measurement. If no span was active or the span was not sampled this will
+	// be empty.
+	TraceID []byte `json:",omitempty"`
+}

vendor/go.opentelemetry.io/otel/sdk/metric/internal/exemplar/filter.go

@@ -1,40 +1,29 @@
 // Copyright The OpenTelemetry Authors
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
+// SPDX-License-Identifier: Apache-2.0
 
 package exemplar // import "go.opentelemetry.io/otel/sdk/metric/internal/exemplar"
 
 import (
 	"context"
-	"time"
 
-	"go.opentelemetry.io/otel/attribute"
 	"go.opentelemetry.io/otel/trace"
 )
 
-// SampledFilter returns a [Reservoir] wrapping r that will only offer measurements
-// to r if the passed context associated with the measurement contains a sampled
+// Filter determines if a measurement should be offered.
+//
+// The passed ctx needs to contain any baggage or span that were active
+// when the measurement was made. This information may be used by the
+// Reservoir in making a sampling decision.
+type Filter func(context.Context) bool
+
+// SampledFilter is a [Filter] that will only offer measurements
+// if the passed context associated with the measurement contains a sampled
 // [go.opentelemetry.io/otel/trace.SpanContext].
-func SampledFilter[N int64 | float64](r Reservoir[N]) Reservoir[N] {
-	return filtered[N]{Reservoir: r}
+func SampledFilter(ctx context.Context) bool {
+	return trace.SpanContextFromContext(ctx).IsSampled()
 }
 
-type filtered[N int64 | float64] struct {
-	Reservoir[N]
-}
-
-func (f filtered[N]) Offer(ctx context.Context, t time.Time, n N, a []attribute.KeyValue) {
-	if trace.SpanContextFromContext(ctx).IsSampled() {
-		f.Reservoir.Offer(ctx, t, n, a)
-	}
+// AlwaysOnFilter is a [Filter] that always offers measurements.
+func AlwaysOnFilter(ctx context.Context) bool {
+	return true
 }

vendor/go.opentelemetry.io/otel/sdk/metric/internal/exemplar/filtered_reservoir.go

@@ -0,0 +1,49 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package exemplar // import "go.opentelemetry.io/otel/sdk/metric/internal/exemplar"
+
+import (
+	"context"
+	"time"
+
+	"go.opentelemetry.io/otel/attribute"
+)
+
+// FilteredReservoir wraps a [Reservoir] with a filter.
+type FilteredReservoir[N int64 | float64] interface {
+	// Offer accepts the parameters associated with a measurement. The
+	// parameters will be stored as an exemplar if the filter decides to
+	// sample the measurement.
+	//
+	// The passed ctx needs to contain any baggage or span that were active
+	// when the measurement was made. This information may be used by the
+	// Reservoir in making a sampling decision.
+	Offer(ctx context.Context, val N, attr []attribute.KeyValue)
+	// Collect returns all the held exemplars in the reservoir.
+	Collect(dest *[]Exemplar)
+}
+
+// filteredReservoir handles the pre-sampled exemplar of measurements made.
+type filteredReservoir[N int64 | float64] struct {
+	filter    Filter
+	reservoir Reservoir
+}
+
+// NewFilteredReservoir creates a [FilteredReservoir] which only offers values
+// that are allowed by the filter.
+func NewFilteredReservoir[N int64 | float64](f Filter, r Reservoir) FilteredReservoir[N] {
+	return &filteredReservoir[N]{
+		filter:    f,
+		reservoir: r,
+	}
+}
+
+func (f *filteredReservoir[N]) Offer(ctx context.Context, val N, attr []attribute.KeyValue) {
+	if f.filter(ctx) {
+		// only record the current time if we are sampling this measurment.
+		f.reservoir.Offer(ctx, time.Now(), NewValue(val), attr)
+	}
+}
+
+func (f *filteredReservoir[N]) Collect(dest *[]Exemplar) { f.reservoir.Collect(dest) }

vendor/go.opentelemetry.io/otel/sdk/metric/internal/exemplar/hist.go

@@ -1,21 +1,11 @@
 // Copyright The OpenTelemetry Authors
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
+// SPDX-License-Identifier: Apache-2.0
 
 package exemplar // import "go.opentelemetry.io/otel/sdk/metric/internal/exemplar"
 
 import (
 	"context"
+	"slices"
 	"sort"
 	"time"
 
@@ -27,21 +17,30 @@ import (
 // by bounds.
 //
 // The passed bounds will be sorted by this function.
-func Histogram[N int64 | float64](bounds []float64) Reservoir[N] {
-	sort.Float64s(bounds)
-	return &histRes[N]{
+func Histogram(bounds []float64) Reservoir {
+	slices.Sort(bounds)
+	return &histRes{
 		bounds:  bounds,
-		storage: newStorage[N](len(bounds) + 1),
+		storage: newStorage(len(bounds) + 1),
 	}
 }
 
-type histRes[N int64 | float64] struct {
-	*storage[N]
+type histRes struct {
+	*storage
 
 	// bounds are bucket bounds in ascending order.
 	bounds []float64
 }
 
-func (r *histRes[N]) Offer(ctx context.Context, t time.Time, n N, a []attribute.KeyValue) {
-	r.store[sort.SearchFloat64s(r.bounds, float64(n))] = newMeasurement(ctx, t, n, a)
+func (r *histRes) Offer(ctx context.Context, t time.Time, v Value, a []attribute.KeyValue) {
+	var x float64
+	switch v.Type() {
+	case Int64ValueType:
+		x = float64(v.Int64())
+	case Float64ValueType:
+		x = v.Float64()
+	default:
+		panic("unknown value type")
+	}
+	r.store[sort.SearchFloat64s(r.bounds, x)] = newMeasurement(ctx, t, v, a)
 }

vendor/go.opentelemetry.io/otel/sdk/metric/internal/exemplar/rand.go

@@ -1,16 +1,5 @@
 // Copyright The OpenTelemetry Authors
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
+// SPDX-License-Identifier: Apache-2.0
 
 package exemplar // import "go.opentelemetry.io/otel/sdk/metric/internal/exemplar"
 
@@ -18,17 +7,21 @@ import (
 	"context"
 	"math"
 	"math/rand"
+	"sync"
 	"time"
 
 	"go.opentelemetry.io/otel/attribute"
-	"go.opentelemetry.io/otel/sdk/metric/metricdata"
 )
 
-// rng is used to make sampling decisions.
-//
-// Do not use crypto/rand. There is no reason for the decrease in performance
-// given this is not a security sensitive decision.
-var rng = rand.New(rand.NewSource(time.Now().UnixNano()))
+var (
+	// rng is used to make sampling decisions.
+	//
+	// Do not use crypto/rand. There is no reason for the decrease in performance
+	// given this is not a security sensitive decision.
+	rng = rand.New(rand.NewSource(time.Now().UnixNano()))
+	// Ensure concurrent safe accecess to rng and its underlying source.
+	rngMu sync.Mutex
+)
 
 // random returns, as a float64, a uniform pseudo-random number in the open
 // interval (0.0,1.0).
@@ -50,6 +43,9 @@ func random() float64 {
 	//
 	// There are likely many other methods to explore here as well.
 
+	rngMu.Lock()
+	defer rngMu.Unlock()
+
 	f := rng.Float64()
 	for f == 0 {
 		f = rng.Float64()
@@ -61,14 +57,14 @@ func random() float64 {
 // are k or less measurements made, the Reservoir will sample each one. If
 // there are more than k, the Reservoir will then randomly sample all
 // additional measurement with a decreasing probability.
-func FixedSize[N int64 | float64](k int) Reservoir[N] {
-	r := &randRes[N]{storage: newStorage[N](k)}
+func FixedSize(k int) Reservoir {
+	r := &randRes{storage: newStorage(k)}
 	r.reset()
 	return r
 }
 
-type randRes[N int64 | float64] struct {
-	*storage[N]
+type randRes struct {
+	*storage
 
 	// count is the number of measurement seen.
 	count int64
@@ -80,7 +76,7 @@ type randRes[N int64 | float64] struct {
 	w float64
 }
 
-func (r *randRes[N]) Offer(ctx context.Context, t time.Time, n N, a []attribute.KeyValue) {
+func (r *randRes) Offer(ctx context.Context, t time.Time, n Value, a []attribute.KeyValue) {
 	// The following algorithm is "Algorithm L" from Li, Kim-Hung (4 December
 	// 1994). "Reservoir-Sampling Algorithms of Time Complexity
 	// O(n(1+log(N/n)))". ACM Transactions on Mathematical Software. 20 (4):
@@ -136,7 +132,7 @@ func (r *randRes[N]) Offer(ctx context.Context, t time.Time, n N, a []attribute.
 }
 
 // reset resets r to the initial state.
-func (r *randRes[N]) reset() {
+func (r *randRes) reset() {
 	// This resets the number of exemplars known.
 	r.count = 0
 	// Random index inserts should only happen after the storage is full.
@@ -158,7 +154,7 @@ func (r *randRes[N]) reset() {
 
 // advance updates the count at which the offered measurement will overwrite an
 // existing exemplar.
-func (r *randRes[N]) advance() {
+func (r *randRes) advance() {
 	// Calculate the next value in the random number series.
 	//
 	// The current value of r.w is based on the max of a distribution of random
@@ -185,7 +181,7 @@ func (r *randRes[N]) advance() {
 	r.next += int64(math.Log(random())/math.Log(1-r.w)) + 1
 }
 
-func (r *randRes[N]) Collect(dest *[]metricdata.Exemplar[N]) {
+func (r *randRes) Collect(dest *[]Exemplar) {
 	r.storage.Collect(dest)
 	// Call reset here even though it will reset r.count and restart the random
 	// number series. This will persist any old exemplars as long as no new

vendor/go.opentelemetry.io/otel/sdk/metric/internal/exemplar/reservoir.go

@@ -1,16 +1,5 @@
 // Copyright The OpenTelemetry Authors
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
+// SPDX-License-Identifier: Apache-2.0
 
 package exemplar // import "go.opentelemetry.io/otel/sdk/metric/internal/exemplar"
 
@@ -19,11 +8,10 @@ import (
 	"time"
 
 	"go.opentelemetry.io/otel/attribute"
-	"go.opentelemetry.io/otel/sdk/metric/metricdata"
 )
 
 // Reservoir holds the sampled exemplar of measurements made.
-type Reservoir[N int64 | float64] interface {
+type Reservoir interface {
 	// Offer accepts the parameters associated with a measurement. The
 	// parameters will be stored as an exemplar if the Reservoir decides to
 	// sample the measurement.
@@ -35,10 +23,10 @@ type Reservoir[N int64 | float64] interface {
 	// The time t is the time when the measurement was made. The val and attr
 	// parameters are the value and dropped (filtered) attributes of the
 	// measurement respectively.
-	Offer(ctx context.Context, t time.Time, val N, attr []attribute.KeyValue)
+	Offer(ctx context.Context, t time.Time, val Value, attr []attribute.KeyValue)
 
 	// Collect returns all the held exemplars.
 	//
 	// The Reservoir state is preserved after this call.
-	Collect(dest *[]metricdata.Exemplar[N])
+	Collect(dest *[]Exemplar)
 }

vendor/go.opentelemetry.io/otel/sdk/metric/internal/exemplar/storage.go

@@ -1,16 +1,5 @@
 // Copyright The OpenTelemetry Authors
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
+// SPDX-License-Identifier: Apache-2.0
 
 package exemplar // import "go.opentelemetry.io/otel/sdk/metric/internal/exemplar"
 
@@ -19,27 +8,26 @@ import (
 	"time"
 
 	"go.opentelemetry.io/otel/attribute"
-	"go.opentelemetry.io/otel/sdk/metric/metricdata"
 	"go.opentelemetry.io/otel/trace"
 )
 
 // storage is an exemplar storage for [Reservoir] implementations.
-type storage[N int64 | float64] struct {
+type storage struct {
 	// store are the measurements sampled.
 	//
 	// This does not use []metricdata.Exemplar because it potentially would
 	// require an allocation for trace and span IDs in the hot path of Offer.
-	store []measurement[N]
+	store []measurement
 }
 
-func newStorage[N int64 | float64](n int) *storage[N] {
-	return &storage[N]{store: make([]measurement[N], n)}
+func newStorage(n int) *storage {
+	return &storage{store: make([]measurement, n)}
 }
 
 // Collect returns all the held exemplars.
 //
 // The Reservoir state is preserved after this call.
-func (r *storage[N]) Collect(dest *[]metricdata.Exemplar[N]) {
+func (r *storage) Collect(dest *[]Exemplar) {
 	*dest = reset(*dest, len(r.store), len(r.store))
 	var n int
 	for _, m := range r.store {
@@ -54,13 +42,13 @@ func (r *storage[N]) Collect(dest *[]metricdata.Exemplar[N]) {
 }
 
 // measurement is a measurement made by a telemetry system.
-type measurement[N int64 | float64] struct {
+type measurement struct {
 	// FilteredAttributes are the attributes dropped during the measurement.
 	FilteredAttributes []attribute.KeyValue
 	// Time is the time when the measurement was made.
 	Time time.Time
 	// Value is the value of the measurement.
-	Value N
+	Value Value
 	// SpanContext is the SpanContext active when a measurement was made.
 	SpanContext trace.SpanContext
 
@@ -68,8 +56,8 @@ type measurement[N int64 | float64] struct {
 }
 
 // newMeasurement returns a new non-empty Measurement.
-func newMeasurement[N int64 | float64](ctx context.Context, ts time.Time, v N, droppedAttr []attribute.KeyValue) measurement[N] {
-	return measurement[N]{
+func newMeasurement(ctx context.Context, ts time.Time, v Value, droppedAttr []attribute.KeyValue) measurement {
+	return measurement{
 		FilteredAttributes: droppedAttr,
 		Time:               ts,
 		Value:              v,
@@ -78,8 +66,8 @@ func newMeasurement[N int64 | float64](ctx context.Context, ts time.Time, v N, d
 	}
 }
 
-// Exemplar returns m as a [metricdata.Exemplar].
-func (m measurement[N]) Exemplar(dest *metricdata.Exemplar[N]) {
+// Exemplar returns m as an [Exemplar].
+func (m measurement) Exemplar(dest *Exemplar) {
 	dest.FilteredAttributes = m.FilteredAttributes
 	dest.Time = m.Time
 	dest.Value = m.Value

vendor/go.opentelemetry.io/otel/sdk/metric/internal/exemplar/value.go

@@ -0,0 +1,58 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package exemplar // import "go.opentelemetry.io/otel/sdk/metric/internal/exemplar"
+
+import "math"
+
+// ValueType identifies the type of value used in exemplar data.
+type ValueType uint8
+
+const (
+	// UnknownValueType should not be used. It represents a misconfigured
+	// Value.
+	UnknownValueType ValueType = 0
+	// Int64ValueType represents a Value with int64 data.
+	Int64ValueType ValueType = 1
+	// Float64ValueType represents a Value with float64 data.
+	Float64ValueType ValueType = 2
+)
+
+// Value is the value of data held by an exemplar.
+type Value struct {
+	t   ValueType
+	val uint64
+}
+
+// NewValue returns a new [Value] for the provided value.
+func NewValue[N int64 | float64](value N) Value {
+	switch v := any(value).(type) {
+	case int64:
+		return Value{t: Int64ValueType, val: uint64(v)}
+	case float64:
+		return Value{t: Float64ValueType, val: math.Float64bits(v)}
+	}
+	return Value{}
+}
+
+// Type returns the [ValueType] of data held by v.
+func (v Value) Type() ValueType { return v.t }
+
+// Int64 returns the value of v as an int64. If the ValueType of v is not an
+// Int64ValueType, 0 is returned.
+func (v Value) Int64() int64 {
+	if v.t == Int64ValueType {
+		// Assumes the correct int64 was stored in v.val based on type.
+		return int64(v.val) // nolint: gosec
+	}
+	return 0
+}
+
+// Float64 returns the value of v as an float64. If the ValueType of v is not
+// an Float64ValueType, 0 is returned.
+func (v Value) Float64() float64 {
+	if v.t == Float64ValueType {
+		return math.Float64frombits(v.val)
+	}
+	return 0
+}

vendor/go.opentelemetry.io/otel/sdk/metric/internal/reuse_slice.go

@@ -1,16 +1,5 @@
 // Copyright The OpenTelemetry Authors
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
+// SPDX-License-Identifier: Apache-2.0
 
 package internal // import "go.opentelemetry.io/otel/sdk/metric/internal"
 

vendor/go.opentelemetry.io/otel/sdk/metric/internal/x/x.go

@@ -1,16 +1,5 @@
 // Copyright The OpenTelemetry Authors
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
+// SPDX-License-Identifier: Apache-2.0
 
 // Package x contains support for OTel metric SDK experimental features.
 //

vendor/go.opentelemetry.io/otel/sdk/metric/manual_reader.go

@@ -1,16 +1,5 @@
 // Copyright The OpenTelemetry Authors
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
+// SPDX-License-Identifier: Apache-2.0
 
 package metric // import "go.opentelemetry.io/otel/sdk/metric"
 

vendor/go.opentelemetry.io/otel/sdk/metric/meter.go

@@ -1,16 +1,5 @@
 // Copyright The OpenTelemetry Authors
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
+// SPDX-License-Identifier: Apache-2.0
 
 package metric // import "go.opentelemetry.io/otel/sdk/metric"
 
@@ -119,6 +108,21 @@ func (m *meter) Int64Histogram(name string, options ...metric.Int64HistogramOpti
 	return i, validateInstrumentName(name)
 }
 
+// Int64Gauge returns a new instrument identified by name and configured
+// with options. The instrument is used to synchronously record the
+// distribution of int64 measurements during a computational operation.
+func (m *meter) Int64Gauge(name string, options ...metric.Int64GaugeOption) (metric.Int64Gauge, error) {
+	cfg := metric.NewInt64GaugeConfig(options...)
+	const kind = InstrumentKindGauge
+	p := int64InstProvider{m}
+	i, err := p.lookup(kind, name, cfg.Description(), cfg.Unit())
+	if err != nil {
+		return i, err
+	}
+
+	return i, validateInstrumentName(name)
+}
+
 // int64ObservableInstrument returns a new observable identified by the Instrument.
 // It registers callbacks for each reader's pipeline.
 func (m *meter) int64ObservableInstrument(id Instrument, callbacks []metric.Int64Callback) (int64Observable, error) {
@@ -181,6 +185,11 @@ func (m *meter) Int64ObservableCounter(name string, options ...metric.Int64Obser
 // configured with options. The instrument is used to asynchronously record
 // int64 measurements once per a measurement collection cycle. Only the
 // measurements recorded during the collection cycle are exported.
+//
+// If Int64ObservableUpDownCounter is invoked repeatedly with the same Name,
+// Description, and Unit, only the first set of callbacks provided are used.
+// Use meter.RegisterCallback and Registration.Unregister to manage callbacks
+// if instrumentation can be created multiple times with different callbacks.
 func (m *meter) Int64ObservableUpDownCounter(name string, options ...metric.Int64ObservableUpDownCounterOption) (metric.Int64ObservableUpDownCounter, error) {
 	cfg := metric.NewInt64ObservableUpDownCounterConfig(options...)
 	id := Instrument{
@@ -197,6 +206,11 @@ func (m *meter) Int64ObservableUpDownCounter(name string, options ...metric.Int6
 // configured with options. The instrument is used to asynchronously record
 // instantaneous int64 measurements once per a measurement collection cycle.
 // Only the measurements recorded during the collection cycle are exported.
+//
+// If Int64ObservableGauge is invoked repeatedly with the same Name,
+// Description, and Unit, only the first set of callbacks provided are used.
+// Use meter.RegisterCallback and Registration.Unregister to manage callbacks
+// if instrumentation can be created multiple times with different callbacks.
 func (m *meter) Int64ObservableGauge(name string, options ...metric.Int64ObservableGaugeOption) (metric.Int64ObservableGauge, error) {
 	cfg := metric.NewInt64ObservableGaugeConfig(options...)
 	id := Instrument{
@@ -253,6 +267,21 @@ func (m *meter) Float64Histogram(name string, options ...metric.Float64Histogram
 	return i, validateInstrumentName(name)
 }
 
+// Float64Gauge returns a new instrument identified by name and configured
+// with options. The instrument is used to synchronously record the
+// distribution of float64 measurements during a computational operation.
+func (m *meter) Float64Gauge(name string, options ...metric.Float64GaugeOption) (metric.Float64Gauge, error) {
+	cfg := metric.NewFloat64GaugeConfig(options...)
+	const kind = InstrumentKindGauge
+	p := float64InstProvider{m}
+	i, err := p.lookup(kind, name, cfg.Description(), cfg.Unit())
+	if err != nil {
+		return i, err
+	}
+
+	return i, validateInstrumentName(name)
+}
+
 // float64ObservableInstrument returns a new observable identified by the Instrument.
 // It registers callbacks for each reader's pipeline.
 func (m *meter) float64ObservableInstrument(id Instrument, callbacks []metric.Float64Callback) (float64Observable, error) {
@@ -315,6 +344,11 @@ func (m *meter) Float64ObservableCounter(name string, options ...metric.Float64O
 // and configured with options. The instrument is used to asynchronously record
 // float64 measurements once per a measurement collection cycle. Only the
 // measurements recorded during the collection cycle are exported.
+//
+// If Float64ObservableUpDownCounter is invoked repeatedly with the same Name,
+// Description, and Unit, only the first set of callbacks provided are used.
+// Use meter.RegisterCallback and Registration.Unregister to manage callbacks
+// if instrumentation can be created multiple times with different callbacks.
 func (m *meter) Float64ObservableUpDownCounter(name string, options ...metric.Float64ObservableUpDownCounterOption) (metric.Float64ObservableUpDownCounter, error) {
 	cfg := metric.NewFloat64ObservableUpDownCounterConfig(options...)
 	id := Instrument{
@@ -331,6 +365,11 @@ func (m *meter) Float64ObservableUpDownCounter(name string, options ...metric.Fl
 // configured with options. The instrument is used to asynchronously record
 // instantaneous float64 measurements once per a measurement collection cycle.
 // Only the measurements recorded during the collection cycle are exported.
+//
+// If Float64ObservableGauge is invoked repeatedly with the same Name,
+// Description, and Unit, only the first set of callbacks provided are used.
+// Use meter.RegisterCallback and Registration.Unregister to manage callbacks
+// if instrumentation can be created multiple times with different callbacks.
 func (m *meter) Float64ObservableGauge(name string, options ...metric.Float64ObservableGaugeOption) (metric.Float64ObservableGauge, error) {
 	cfg := metric.NewFloat64ObservableGaugeConfig(options...)
 	id := Instrument{

vendor/go.opentelemetry.io/otel/sdk/metric/metricdata/README.md

@@ -0,0 +1,3 @@
+# SDK Metric data
+
+[![PkgGoDev](https://pkg.go.dev/badge/go.opentelemetry.io/otel/sdk/metric/metricdata)](https://pkg.go.dev/go.opentelemetry.io/otel/sdk/metric/metricdata)

vendor/go.opentelemetry.io/otel/sdk/metric/metricdata/data.go

@@ -1,16 +1,5 @@
 // Copyright The OpenTelemetry Authors
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
+// SPDX-License-Identifier: Apache-2.0
 
 package metricdata // import "go.opentelemetry.io/otel/sdk/metric/metricdata"
 

vendor/go.opentelemetry.io/otel/sdk/metric/metricdata/temporality.go

@@ -1,16 +1,5 @@
 // Copyright The OpenTelemetry Authors
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
+// SPDX-License-Identifier: Apache-2.0
 
 //go:generate stringer -type=Temporality
 

vendor/go.opentelemetry.io/otel/sdk/metric/periodic_reader.go

@@ -1,16 +1,5 @@
 // Copyright The OpenTelemetry Authors
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
+// SPDX-License-Identifier: Apache-2.0
 
 package metric // import "go.opentelemetry.io/otel/sdk/metric"
 
@@ -345,7 +334,7 @@ func (r *PeriodicReader) Shutdown(ctx context.Context) error {
 		}
 
 		sErr := r.exporter.Shutdown(ctx)
-		if err == nil || err == ErrReaderShutdown {
+		if err == nil || errors.Is(err, ErrReaderShutdown) {
 			err = sErr
 		}
 

vendor/go.opentelemetry.io/otel/sdk/metric/pipeline.go

@@ -1,16 +1,5 @@
 // Copyright The OpenTelemetry Authors
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
+// SPDX-License-Identifier: Apache-2.0
 
 package metric // import "go.opentelemetry.io/otel/sdk/metric"
 
@@ -458,7 +447,12 @@ func (i *inserter[N]) aggregateFunc(b aggregate.Builder[N], agg Aggregation, kin
 	case AggregationDrop:
 		// Return nil in and out to signify the drop aggregator.
 	case AggregationLastValue:
-		meas, comp = b.LastValue()
+		switch kind {
+		case InstrumentKindGauge:
+			meas, comp = b.LastValue()
+		case InstrumentKindObservableGauge:
+			meas, comp = b.PrecomputedLastValue()
+		}
 	case AggregationSum:
 		switch kind {
 		case InstrumentKindObservableCounter:
@@ -475,7 +469,7 @@ func (i *inserter[N]) aggregateFunc(b aggregate.Builder[N], agg Aggregation, kin
 	case AggregationExplicitBucketHistogram:
 		var noSum bool
 		switch kind {
-		case InstrumentKindUpDownCounter, InstrumentKindObservableUpDownCounter, InstrumentKindObservableGauge:
+		case InstrumentKindUpDownCounter, InstrumentKindObservableUpDownCounter, InstrumentKindObservableGauge, InstrumentKindGauge:
 			// The sum should not be collected for any instrument that can make
 			// negative measurements:
 			// https://github.com/open-telemetry/opentelemetry-specification/blob/v1.21.0/specification/metrics/sdk.md#histogram-aggregations
@@ -485,7 +479,7 @@ func (i *inserter[N]) aggregateFunc(b aggregate.Builder[N], agg Aggregation, kin
 	case AggregationBase2ExponentialHistogram:
 		var noSum bool
 		switch kind {
-		case InstrumentKindUpDownCounter, InstrumentKindObservableUpDownCounter, InstrumentKindObservableGauge:
+		case InstrumentKindUpDownCounter, InstrumentKindObservableUpDownCounter, InstrumentKindObservableGauge, InstrumentKindGauge:
 			// The sum should not be collected for any instrument that can make
 			// negative measurements:
 			// https://github.com/open-telemetry/opentelemetry-specification/blob/v1.21.0/specification/metrics/sdk.md#histogram-aggregations
@@ -508,6 +502,7 @@ func (i *inserter[N]) aggregateFunc(b aggregate.Builder[N], agg Aggregation, kin
 // | Counter                  | ✓    |           | ✓   | ✓         | ✓                     |
 // | UpDownCounter            | ✓    |           | ✓   | ✓         | ✓                     |
 // | Histogram                | ✓    |           | ✓   | ✓         | ✓                     |
+// | Gauge                    | ✓    | ✓         |     | ✓         | ✓                     |
 // | Observable Counter       | ✓    |           | ✓   | ✓         | ✓                     |
 // | Observable UpDownCounter | ✓    |           | ✓   | ✓         | ✓                     |
 // | Observable Gauge         | ✓    | ✓         |     | ✓         | ✓                     |.
@@ -520,6 +515,7 @@ func isAggregatorCompatible(kind InstrumentKind, agg Aggregation) error {
 		case InstrumentKindCounter,
 			InstrumentKindUpDownCounter,
 			InstrumentKindHistogram,
+			InstrumentKindGauge,
 			InstrumentKindObservableCounter,
 			InstrumentKindObservableUpDownCounter,
 			InstrumentKindObservableGauge:
@@ -537,7 +533,8 @@ func isAggregatorCompatible(kind InstrumentKind, agg Aggregation) error {
 			return errIncompatibleAggregation
 		}
 	case AggregationLastValue:
-		if kind == InstrumentKindObservableGauge {
+		switch kind {
+		case InstrumentKindObservableGauge, InstrumentKindGauge:
 			return nil
 		}
 		// TODO: review need for aggregation check after

vendor/go.opentelemetry.io/otel/sdk/metric/provider.go

@@ -1,16 +1,5 @@
 // Copyright The OpenTelemetry Authors
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
+// SPDX-License-Identifier: Apache-2.0
 
 package metric // import "go.opentelemetry.io/otel/sdk/metric"
 

vendor/go.opentelemetry.io/otel/sdk/metric/reader.go

@@ -1,16 +1,5 @@
 // Copyright The OpenTelemetry Authors
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
+// SPDX-License-Identifier: Apache-2.0
 
 package metric // import "go.opentelemetry.io/otel/sdk/metric"
 
@@ -45,7 +34,7 @@ var errNonPositiveDuration = fmt.Errorf("non-positive duration")
 // start of bi-directional control flow.
 //
 // Typically, push-based exporters that are periodic will
-// implement PeroidicExporter themselves and construct a
+// implement PeriodicExporter themselves and construct a
 // PeriodicReader to satisfy this interface.
 //
 // Pull-based exporters will typically implement Register
@@ -159,7 +148,7 @@ func DefaultAggregationSelector(ik InstrumentKind) Aggregation {
 	switch ik {
 	case InstrumentKindCounter, InstrumentKindUpDownCounter, InstrumentKindObservableCounter, InstrumentKindObservableUpDownCounter:
 		return AggregationSum{}
-	case InstrumentKindObservableGauge:
+	case InstrumentKindObservableGauge, InstrumentKindGauge:
 		return AggregationLastValue{}
 	case InstrumentKindHistogram:
 		return AggregationExplicitBucketHistogram{
@@ -177,7 +166,7 @@ type ReaderOption interface {
 	ManualReaderOption
 }
 
-// WithProducers registers producers as an external Producer of metric data
+// WithProducer registers producers as an external Producer of metric data
 // for this Reader.
 func WithProducer(p Producer) ReaderOption {
 	return producerOption{p: p}

vendor/go.opentelemetry.io/otel/sdk/metric/version.go

@@ -1,20 +1,9 @@
 // Copyright The OpenTelemetry Authors
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
+// SPDX-License-Identifier: Apache-2.0
 
 package metric // import "go.opentelemetry.io/otel/sdk/metric"
 
 // version is the current release version of the metric SDK in use.
 func version() string {
-	return "1.24.0"
+	return "1.29.0"
 }

vendor/go.opentelemetry.io/otel/sdk/metric/view.go

@@ -1,16 +1,5 @@
 // Copyright The OpenTelemetry Authors
-//
-// Licensed under the Apache License, Version 2.0 (the "License");
-// you may not use this file except in compliance with the License.
-// You may obtain a copy of the License at
-//
-//     http://www.apache.org/licenses/LICENSE-2.0
-//
-// Unless required by applicable law or agreed to in writing, software
-// distributed under the License is distributed on an "AS IS" BASIS,
-// WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
-// See the License for the specific language governing permissions and
-// limitations under the License.
+// SPDX-License-Identifier: Apache-2.0
 
 package metric // import "go.opentelemetry.io/otel/sdk/metric"
 
@@ -54,7 +43,7 @@ type View func(Instrument) (Stream, bool)
 // of the default. If you need to zero out an Stream field returned from a
 // View, create a View directly.
 func NewView(criteria Instrument, mask Stream) View {
-	if criteria.empty() {
+	if criteria.IsEmpty() {
 		global.Error(
 			errEmptyView, "dropping view",
 			"mask", mask,

vendor/go.opentelemetry.io/otel/sdk/resource/builtin.go

@@ -9,9 +9,11 @@ import (
 	"os"
 	"path/filepath"
 
+	"github.com/google/uuid"
+
 	"go.opentelemetry.io/otel/attribute"
 	"go.opentelemetry.io/otel/sdk"
-	semconv "go.opentelemetry.io/otel/semconv/v1.24.0"
+	semconv "go.opentelemetry.io/otel/semconv/v1.26.0"
 )
 
 type (
@@ -36,6 +38,8 @@ type (
 	}
 
 	defaultServiceNameDetector struct{}
+
+	defaultServiceInstanceIDDetector struct{}
 )
 
 var (
@@ -43,6 +47,7 @@ var (
 	_ Detector = host{}
 	_ Detector = stringDetector{}
 	_ Detector = defaultServiceNameDetector{}
+	_ Detector = defaultServiceInstanceIDDetector{}
 )
 
 // Detect returns a *Resource that describes the OpenTelemetry SDK used.
@@ -95,3 +100,19 @@ func (defaultServiceNameDetector) Detect(ctx context.Context) (*Resource, error)
 		},
 	).Detect(ctx)
 }
+
+// Detect implements Detector.
+func (defaultServiceInstanceIDDetector) Detect(ctx context.Context) (*Resource, error) {
+	return StringDetector(
+		semconv.SchemaURL,
+		semconv.ServiceInstanceIDKey,
+		func() (string, error) {
+			version4Uuid, err := uuid.NewRandom()
+			if err != nil {
+				return "", err
+			}
+
+			return version4Uuid.String(), nil
+		},
+	).Detect(ctx)
+}

vendor/go.opentelemetry.io/otel/sdk/resource/container.go

@@ -11,7 +11,7 @@ import (
 	"os"
 	"regexp"
 
-	semconv "go.opentelemetry.io/otel/semconv/v1.24.0"
+	semconv "go.opentelemetry.io/otel/semconv/v1.26.0"
 )
 
 type containerIDProvider func() (string, error)

vendor/go.opentelemetry.io/otel/sdk/resource/env.go

@@ -12,7 +12,7 @@ import (
 
 	"go.opentelemetry.io/otel"
 	"go.opentelemetry.io/otel/attribute"
-	semconv "go.opentelemetry.io/otel/semconv/v1.24.0"
+	semconv "go.opentelemetry.io/otel/semconv/v1.26.0"
 )
 
 const (

vendor/go.opentelemetry.io/otel/sdk/resource/host_id.go

@@ -8,7 +8,7 @@ import (
 	"errors"
 	"strings"
 
-	semconv "go.opentelemetry.io/otel/semconv/v1.24.0"
+	semconv "go.opentelemetry.io/otel/semconv/v1.26.0"
 )
 
 type hostIDProvider func() (string, error)

vendor/go.opentelemetry.io/otel/sdk/resource/os.go

@@ -8,7 +8,7 @@ import (
 	"strings"
 
 	"go.opentelemetry.io/otel/attribute"
-	semconv "go.opentelemetry.io/otel/semconv/v1.24.0"
+	semconv "go.opentelemetry.io/otel/semconv/v1.26.0"
 )
 
 type osDescriptionProvider func() (string, error)

vendor/go.opentelemetry.io/otel/sdk/resource/process.go

@@ -11,7 +11,7 @@ import (
 	"path/filepath"
 	"runtime"
 
-	semconv "go.opentelemetry.io/otel/semconv/v1.24.0"
+	semconv "go.opentelemetry.io/otel/semconv/v1.26.0"
 )
 
 type (

vendor/go.opentelemetry.io/otel/sdk/resource/resource.go

@@ -11,6 +11,7 @@ import (
 
 	"go.opentelemetry.io/otel"
 	"go.opentelemetry.io/otel/attribute"
+	"go.opentelemetry.io/otel/sdk/internal/x"
 )
 
 // Resource describes an entity about which identifying information
@@ -218,11 +219,17 @@ func Empty() *Resource {
 func Default() *Resource {
 	defaultResourceOnce.Do(func() {
 		var err error
-		defaultResource, err = Detect(
-			context.Background(),
+		defaultDetectors := []Detector{
 			defaultServiceNameDetector{},
 			fromEnv{},
 			telemetrySDK{},
+		}
+		if x.Resource.Enabled() {
+			defaultDetectors = append([]Detector{defaultServiceInstanceIDDetector{}}, defaultDetectors...)
+		}
+		defaultResource, err = Detect(
+			context.Background(),
+			defaultDetectors...,
 		)
 		if err != nil {
 			otel.Handle(err)

vendor/go.opentelemetry.io/otel/sdk/trace/batch_span_processor.go

@@ -381,7 +381,7 @@ func (bsp *batchSpanProcessor) enqueueBlockOnQueueFull(ctx context.Context, sd R
 	}
 }
 
-func (bsp *batchSpanProcessor) enqueueDrop(ctx context.Context, sd ReadOnlySpan) bool {
+func (bsp *batchSpanProcessor) enqueueDrop(_ context.Context, sd ReadOnlySpan) bool {
 	if !sd.SpanContext().IsSampled() {
 		return false
 	}

vendor/go.opentelemetry.io/otel/sdk/trace/evictedqueue.go

@@ -3,23 +3,43 @@
 
 package trace // import "go.opentelemetry.io/otel/sdk/trace"
 
+import (
+	"slices"
+	"sync"
+
+	"go.opentelemetry.io/otel/internal/global"
+)
+
 // evictedQueue is a FIFO queue with a configurable capacity.
-type evictedQueue struct {
-	queue        []interface{}
+type evictedQueue[T any] struct {
+	queue        []T
 	capacity     int
 	droppedCount int
+	logDropped   func()
 }
 
-func newEvictedQueue(capacity int) evictedQueue {
+func newEvictedQueueEvent(capacity int) evictedQueue[Event] {
 	// Do not pre-allocate queue, do this lazily.
-	return evictedQueue{capacity: capacity}
+	return evictedQueue[Event]{
+		capacity:   capacity,
+		logDropped: sync.OnceFunc(func() { global.Warn("limit reached: dropping trace trace.Event") }),
+	}
+}
+
+func newEvictedQueueLink(capacity int) evictedQueue[Link] {
+	// Do not pre-allocate queue, do this lazily.
+	return evictedQueue[Link]{
+		capacity:   capacity,
+		logDropped: sync.OnceFunc(func() { global.Warn("limit reached: dropping trace trace.Link") }),
+	}
 }
 
 // add adds value to the evictedQueue eq. If eq is at capacity, the oldest
 // queued value will be discarded and the drop count incremented.
-func (eq *evictedQueue) add(value interface{}) {
+func (eq *evictedQueue[T]) add(value T) {
 	if eq.capacity == 0 {
 		eq.droppedCount++
+		eq.logDropped()
 		return
 	}
 
@@ -28,6 +48,12 @@ func (eq *evictedQueue) add(value interface{}) {
 		copy(eq.queue[:eq.capacity-1], eq.queue[1:])
 		eq.queue = eq.queue[:eq.capacity-1]
 		eq.droppedCount++
+		eq.logDropped()
 	}
 	eq.queue = append(eq.queue, value)
 }
+
+// copy returns a copy of the evictedQueue.
+func (eq *evictedQueue[T]) copy() []T {
+	return slices.Clone(eq.queue)
+}

vendor/go.opentelemetry.io/otel/sdk/trace/id_generator.go

@@ -41,7 +41,12 @@ func (gen *randomIDGenerator) NewSpanID(ctx context.Context, traceID trace.Trace
 	gen.Lock()
 	defer gen.Unlock()
 	sid := trace.SpanID{}
-	_, _ = gen.randSource.Read(sid[:])
+	for {
+		_, _ = gen.randSource.Read(sid[:])
+		if sid.IsValid() {
+			break
+		}
+	}
 	return sid
 }
 
@@ -51,9 +56,19 @@ func (gen *randomIDGenerator) NewIDs(ctx context.Context) (trace.TraceID, trace.
 	gen.Lock()
 	defer gen.Unlock()
 	tid := trace.TraceID{}
-	_, _ = gen.randSource.Read(tid[:])
 	sid := trace.SpanID{}
-	_, _ = gen.randSource.Read(sid[:])
+	for {
+		_, _ = gen.randSource.Read(tid[:])
+		if tid.IsValid() {
+			break
+		}
+	}
+	for {
+		_, _ = gen.randSource.Read(sid[:])
+		if sid.IsValid() {
+			break
+		}
+	}
 	return tid, sid
 }
 

vendor/go.opentelemetry.io/otel/sdk/trace/provider.go

@@ -291,7 +291,7 @@ func (p *TracerProvider) Shutdown(ctx context.Context) error {
 				retErr = err
 			} else {
 				// Poor man's list of errors
-				retErr = fmt.Errorf("%v; %v", retErr, err)
+				retErr = fmt.Errorf("%w; %w", retErr, err)
 			}
 		}
 	}

vendor/go.opentelemetry.io/otel/sdk/trace/snapshot.go

@@ -99,7 +99,7 @@ func (s snapshot) InstrumentationScope() instrumentation.Scope {
 
 // InstrumentationLibrary returns information about the instrumentation
 // library that created the span.
-func (s snapshot) InstrumentationLibrary() instrumentation.Library {
+func (s snapshot) InstrumentationLibrary() instrumentation.Library { //nolint:staticcheck // This method needs to be define for backwards compatibility
 	return s.instrumentationScope
 }
 

vendor/go.opentelemetry.io/otel/sdk/trace/span.go

@@ -17,10 +17,10 @@ import (
 
 	"go.opentelemetry.io/otel/attribute"
 	"go.opentelemetry.io/otel/codes"
+	"go.opentelemetry.io/otel/internal/global"
 	"go.opentelemetry.io/otel/sdk/instrumentation"
-	"go.opentelemetry.io/otel/sdk/internal"
 	"go.opentelemetry.io/otel/sdk/resource"
-	semconv "go.opentelemetry.io/otel/semconv/v1.24.0"
+	semconv "go.opentelemetry.io/otel/semconv/v1.26.0"
 	"go.opentelemetry.io/otel/trace"
 	"go.opentelemetry.io/otel/trace/embedded"
 )
@@ -62,7 +62,7 @@ type ReadOnlySpan interface {
 	// InstrumentationLibrary returns information about the instrumentation
 	// library that created the span.
 	// Deprecated: please use InstrumentationScope instead.
-	InstrumentationLibrary() instrumentation.Library
+	InstrumentationLibrary() instrumentation.Library //nolint:staticcheck // This method needs to be define for backwards compatibility
 	// Resource returns information about the entity that produced the span.
 	Resource() *resource.Resource
 	// DroppedAttributes returns the number of attributes dropped by the span
@@ -137,12 +137,13 @@ type recordingSpan struct {
 	// ReadOnlySpan exported when the span ends.
 	attributes        []attribute.KeyValue
 	droppedAttributes int
+	logDropAttrsOnce  sync.Once
 
 	// events are stored in FIFO queue capped by configured limit.
-	events evictedQueue
+	events evictedQueue[Event]
 
 	// links are stored in FIFO queue capped by configured limit.
-	links evictedQueue
+	links evictedQueue[Link]
 
 	// executionTracerTaskEnd ends the execution tracer span.
 	executionTracerTaskEnd func()
@@ -219,7 +220,7 @@ func (s *recordingSpan) SetAttributes(attributes ...attribute.KeyValue) {
 	limit := s.tracer.provider.spanLimits.AttributeCountLimit
 	if limit == 0 {
 		// No attributes allowed.
-		s.droppedAttributes += len(attributes)
+		s.addDroppedAttr(len(attributes))
 		return
 	}
 
@@ -236,7 +237,7 @@ func (s *recordingSpan) SetAttributes(attributes ...attribute.KeyValue) {
 	for _, a := range attributes {
 		if !a.Valid() {
 			// Drop all invalid attributes.
-			s.droppedAttributes++
+			s.addDroppedAttr(1)
 			continue
 		}
 		a = truncateAttr(s.tracer.provider.spanLimits.AttributeValueLengthLimit, a)
@@ -244,6 +245,22 @@ func (s *recordingSpan) SetAttributes(attributes ...attribute.KeyValue) {
 	}
 }
 
+// Declared as a var so tests can override.
+var logDropAttrs = func() {
+	global.Warn("limit reached: dropping trace Span attributes")
+}
+
+// addDroppedAttr adds incr to the count of dropped attributes.
+//
+// The first, and only the first, time this method is called a warning will be
+// logged.
+//
+// This method assumes s.mu.Lock is held by the caller.
+func (s *recordingSpan) addDroppedAttr(incr int) {
+	s.droppedAttributes += incr
+	s.logDropAttrsOnce.Do(logDropAttrs)
+}
+
 // addOverCapAttrs adds the attributes attrs to the span s while
 // de-duplicating the attributes of s and attrs and dropping attributes that
 // exceed the limit.
@@ -273,7 +290,7 @@ func (s *recordingSpan) addOverCapAttrs(limit int, attrs []attribute.KeyValue) {
 	for _, a := range attrs {
 		if !a.Valid() {
 			// Drop all invalid attributes.
-			s.droppedAttributes++
+			s.addDroppedAttr(1)
 			continue
 		}
 
@@ -286,7 +303,7 @@ func (s *recordingSpan) addOverCapAttrs(limit int, attrs []attribute.KeyValue) {
 		if len(s.attributes) >= limit {
 			// Do not just drop all of the remaining attributes, make sure
 			// updates are checked and performed.
-			s.droppedAttributes++
+			s.addDroppedAttr(1)
 		} else {
 			a = truncateAttr(s.tracer.provider.spanLimits.AttributeValueLengthLimit, a)
 			s.attributes = append(s.attributes, a)
@@ -367,7 +384,7 @@ func (s *recordingSpan) End(options ...trace.SpanEndOption) {
 
 	// Store the end time as soon as possible to avoid artificially increasing
 	// the span's duration in case some operation below takes a while.
-	et := internal.MonotonicEndTime(s.startTime)
+	et := monotonicEndTime(s.startTime)
 
 	// Do relative expensive check now that we have an end time and see if we
 	// need to do any more processing.
@@ -418,6 +435,16 @@ func (s *recordingSpan) End(options ...trace.SpanEndOption) {
 	}
 }
 
+// monotonicEndTime returns the end time at present but offset from start,
+// monotonically.
+//
+// The monotonic clock is used in subtractions hence the duration since start
+// added back to start gives end as a monotonic time. See
+// https://golang.org/pkg/time/#hdr-Monotonic_Clocks
+func monotonicEndTime(start time.Time) time.Time {
+	return start.Add(time.Since(start))
+}
+
 // RecordError will record err as a span event for this span. An additional call to
 // SetStatus is required if the Status of the Span should be set to Error, this method
 // does not change the Span status. If this span is not being recorded or err is nil
@@ -585,7 +612,7 @@ func (s *recordingSpan) Links() []Link {
 	if len(s.links.queue) == 0 {
 		return []Link{}
 	}
-	return s.interfaceArrayToLinksArray()
+	return s.links.copy()
 }
 
 // Events returns the events of this span.
@@ -595,7 +622,7 @@ func (s *recordingSpan) Events() []Event {
 	if len(s.events.queue) == 0 {
 		return []Event{}
 	}
-	return s.interfaceArrayToEventArray()
+	return s.events.copy()
 }
 
 // Status returns the status of this span.
@@ -615,7 +642,7 @@ func (s *recordingSpan) InstrumentationScope() instrumentation.Scope {
 
 // InstrumentationLibrary returns the instrumentation.Library associated with
 // the Tracer that created this span.
-func (s *recordingSpan) InstrumentationLibrary() instrumentation.Library {
+func (s *recordingSpan) InstrumentationLibrary() instrumentation.Library { //nolint:staticcheck // This method needs to be define for backwards compatibility
 	s.mu.Lock()
 	defer s.mu.Unlock()
 	return s.tracer.instrumentationScope
@@ -630,7 +657,11 @@ func (s *recordingSpan) Resource() *resource.Resource {
 }
 
 func (s *recordingSpan) AddLink(link trace.Link) {
-	if !s.IsRecording() || !link.SpanContext.IsValid() {
+	if !s.IsRecording() {
+		return
+	}
+	if !link.SpanContext.IsValid() && len(link.Attributes) == 0 &&
+		link.SpanContext.TraceState().Len() == 0 {
 		return
 	}
 
@@ -713,32 +744,16 @@ func (s *recordingSpan) snapshot() ReadOnlySpan {
 	}
 	sd.droppedAttributeCount = s.droppedAttributes
 	if len(s.events.queue) > 0 {
-		sd.events = s.interfaceArrayToEventArray()
+		sd.events = s.events.copy()
 		sd.droppedEventCount = s.events.droppedCount
 	}
 	if len(s.links.queue) > 0 {
-		sd.links = s.interfaceArrayToLinksArray()
+		sd.links = s.links.copy()
 		sd.droppedLinkCount = s.links.droppedCount
 	}
 	return &sd
 }
 
-func (s *recordingSpan) interfaceArrayToLinksArray() []Link {
-	linkArr := make([]Link, 0)
-	for _, value := range s.links.queue {
-		linkArr = append(linkArr, value.(Link))
-	}
-	return linkArr
-}
-
-func (s *recordingSpan) interfaceArrayToEventArray() []Event {
-	eventArr := make([]Event, 0)
-	for _, value := range s.events.queue {
-		eventArr = append(eventArr, value.(Event))
-	}
-	return eventArr
-}
-
 func (s *recordingSpan) addChild() {
 	if !s.IsRecording() {
 		return

vendor/go.opentelemetry.io/otel/sdk/trace/tracer.go

@@ -132,8 +132,8 @@ func (tr *tracer) newRecordingSpan(psc, sc trace.SpanContext, name string, sr Sa
 		spanKind:    trace.ValidateSpanKind(config.SpanKind()),
 		name:        name,
 		startTime:   startTime,
-		events:      newEvictedQueue(tr.provider.spanLimits.EventCountLimit),
-		links:       newEvictedQueue(tr.provider.spanLimits.LinkCountLimit),
+		events:      newEvictedQueueEvent(tr.provider.spanLimits.EventCountLimit),
+		links:       newEvictedQueueLink(tr.provider.spanLimits.LinkCountLimit),
 		tracer:      tr,
 	}
 

vendor/go.opentelemetry.io/otel/sdk/version.go

@@ -5,5 +5,5 @@ package sdk // import "go.opentelemetry.io/otel/sdk"
 
 // Version is the current release version of the OpenTelemetry SDK in use.
 func Version() string {
-	return "1.26.0"
+	return "1.29.0"
 }