internal/exp/metrics: identity types

.github/CODEOWNERS

@@ -120,6 +120,7 @@ internal/collectd/                                       @open-telemetry/collect
 internal/coreinternal/                                   @open-telemetry/collector-contrib-approvers @open-telemetry/collector-approvers
 internal/datadog/                                        @open-telemetry/collector-contrib-approvers @mx-psi @dineshg13
 internal/docker/                                         @open-telemetry/collector-contrib-approvers @rmfitzpatrick @jamesmoessis
+internal/exp/metrics/                                    @open-telemetry/collector-contrib-approvers @sh0rez @RichieSams
 internal/filter/                                         @open-telemetry/collector-contrib-approvers @open-telemetry/collector-approvers
 internal/k8sconfig/                                      @open-telemetry/collector-contrib-approvers @dmitryax
 internal/k8stest/                                        @open-telemetry/collector-contrib-approvers @crobert-1

.github/ISSUE_TEMPLATE/bug_report.yaml

@@ -119,6 +119,7 @@ body:
       - internal/core
       - internal/datadog
       - internal/docker
+      - internal/exp/metrics
       - internal/filter
       - internal/k8sconfig
       - internal/k8stest

.github/ISSUE_TEMPLATE/feature_request.yaml

@@ -113,6 +113,7 @@ body:
       - internal/core
       - internal/datadog
       - internal/docker
+      - internal/exp/metrics
       - internal/filter
       - internal/k8sconfig
       - internal/k8stest

.github/ISSUE_TEMPLATE/other.yaml

@@ -113,6 +113,7 @@ body:
       - internal/core
       - internal/datadog
       - internal/docker
+      - internal/exp/metrics
       - internal/filter
       - internal/k8sconfig
       - internal/k8stest

internal/exp/metrics/Makefile

@@ -0,0 +1 @@
+include ../../../Makefile.Common

internal/exp/metrics/go.mod

@@ -0,0 +1,28 @@
+module github.com/open-telemetry/opentelemetry-collector-contrib/internal/exp/metrics
+
+replace github.com/open-telemetry/opentelemetry-collector-contrib/pkg/pdatautil => ../../../pkg/pdatautil
+
+require (
+	github.com/open-telemetry/opentelemetry-collector-contrib/pkg/pdatautil v0.0.0-00010101000000-000000000000
+	go.opentelemetry.io/collector/pdata v1.1.0
+)
+
+require (
+	github.com/cespare/xxhash/v2 v2.2.0 // indirect
+	github.com/gogo/protobuf v1.3.2 // indirect
+	github.com/golang/protobuf v1.5.3 // indirect
+	github.com/json-iterator/go v1.1.12 // indirect
+	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
+	github.com/modern-go/reflect2 v1.0.2 // indirect
+	go.uber.org/multierr v1.11.0 // indirect
+	golang.org/x/net v0.18.0 // indirect
+	golang.org/x/sys v0.14.0 // indirect
+	golang.org/x/text v0.14.0 // indirect
+	google.golang.org/genproto/googleapis/rpc v0.0.0-20231106174013-bbf56f31fb17 // indirect
+	google.golang.org/grpc v1.61.0 // indirect
+	google.golang.org/protobuf v1.32.0 // indirect
+)
+
+go 1.21
+
+toolchain go1.21.1

internal/exp/metrics/identity/doc.go

@@ -0,0 +1,8 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+// identity types for metrics and sample streams.
+//
+// Use the `Of*(T) -> I` functions to obtain a unique, comparable (==) and
+// hashable (map key) identity value I for T.
+package identity // import "github.com/open-telemetry/opentelemetry-collector-contrib/internal/exp/metrics/identity"

internal/exp/metrics/identity/metric.go

@@ -0,0 +1,71 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package identity // import "github.com/open-telemetry/opentelemetry-collector-contrib/internal/exp/metrics/identity"
+
+import (
+	"hash"
+
+	"go.opentelemetry.io/collector/pdata/pcommon"
+	"go.opentelemetry.io/collector/pdata/pmetric"
+)
+
+type metric = Metric
+
+type Metric struct {
+	scope
+
+	name string
+	unit string
+	ty   pmetric.MetricType
+
+	monotonic   bool
+	temporality pmetric.AggregationTemporality
+}
+
+func (i Metric) Hash() hash.Hash64 {
+	sum := i.scope.Hash()
+	sum.Write([]byte(i.name))
+	sum.Write([]byte(i.unit))
+
+	var mono byte
+	if i.monotonic {
+		mono = 1
+	}
+	sum.Write([]byte{byte(i.ty), mono, byte(i.temporality)})
+	return sum
+}
+
+func (i Metric) Scope() Scope {
+	return i.scope
+}
+
+func OfMetric(scope Scope, m pmetric.Metric) Metric {
+	id := Metric{
+		scope: scope,
+		name:  m.Name(),
+		unit:  m.Unit(),
+		ty:    m.Type(),
+	}
+
+	switch m.Type() {
+	case pmetric.MetricTypeSum:
+		sum := m.Sum()
+		id.monotonic = sum.IsMonotonic()
+		id.temporality = sum.AggregationTemporality()
+	case pmetric.MetricTypeExponentialHistogram:
+		exp := m.ExponentialHistogram()
+		id.monotonic = true
+		id.temporality = exp.AggregationTemporality()
+	case pmetric.MetricTypeHistogram:
+		hist := m.Histogram()
+		id.monotonic = true
+		id.temporality = hist.AggregationTemporality()
+	}
+
+	return id
+}
+
+func OfResourceMetric(res pcommon.Resource, scope pcommon.InstrumentationScope, metric pmetric.Metric) Metric {
+	return OfMetric(OfScope(OfResource(res), scope), metric)
+}

internal/exp/metrics/identity/resource.go

@@ -0,0 +1,31 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package identity // import "github.com/open-telemetry/opentelemetry-collector-contrib/internal/exp/metrics/identity"
+
+import (
+	"hash"
+	"hash/fnv"
+
+	"go.opentelemetry.io/collector/pdata/pcommon"
+
+	"github.com/open-telemetry/opentelemetry-collector-contrib/pkg/pdatautil"
+)
+
+type resource = Resource
+
+type Resource struct {
+	attrs [16]byte
+}
+
+func (r Resource) Hash() hash.Hash64 {
+	sum := fnv.New64a()
+	sum.Write(r.attrs[:])
+	return sum
+}
+
+func OfResource(r pcommon.Resource) Resource {
+	return Resource{
+		attrs: pdatautil.MapHash(r.Attributes()),
+	}
+}

internal/exp/metrics/identity/scope.go

@@ -0,0 +1,43 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package identity // import "github.com/open-telemetry/opentelemetry-collector-contrib/internal/exp/metrics/identity"
+
+import (
+	"hash"
+
+	"go.opentelemetry.io/collector/pdata/pcommon"
+
+	"github.com/open-telemetry/opentelemetry-collector-contrib/pkg/pdatautil"
+)
+
+type scope = Scope
+
+type Scope struct {
+	resource resource
+
+	name    string
+	version string
+	attrs   [16]byte
+}
+
+func (s Scope) Hash() hash.Hash64 {
+	sum := s.resource.Hash()
+	sum.Write([]byte(s.name))
+	sum.Write([]byte(s.version))
+	sum.Write(s.attrs[:])
+	return sum
+}
+
+func (s Scope) Resource() Resource {
+	return s.resource
+}
+
+func OfScope(res Resource, scope pcommon.InstrumentationScope) Scope {
+	return Scope{
+		resource: res,
+		name:     scope.Name(),
+		version:  scope.Version(),
+		attrs:    pdatautil.MapHash(scope.Attributes()),
+	}
+}

internal/exp/metrics/identity/stream.go

@@ -0,0 +1,37 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package identity // import "github.com/open-telemetry/opentelemetry-collector-contrib/internal/exp/metrics/identity"
+
+import (
+	"hash"
+
+	"go.opentelemetry.io/collector/pdata/pcommon"
+	"go.opentelemetry.io/collector/pdata/pmetric"
+
+	"github.com/open-telemetry/opentelemetry-collector-contrib/pkg/pdatautil"
+)
+
+type Stream struct {
+	metric
+	attrs [16]byte
+}
+
+func (i Stream) Hash() hash.Hash64 {
+	sum := i.metric.Hash()
+	sum.Write(i.attrs[:])
+	return sum
+}
+
+func (i Stream) Metric() Metric {
+	return i.metric
+}
+
+func OfStream[DataPoint attrPoint](m Metric, dp DataPoint) Stream {
+	return Stream{metric: m, attrs: pdatautil.MapHash(dp.Attributes())}
+}
+
+type attrPoint interface {
+	pmetric.NumberDataPoint | pmetric.HistogramDataPoint | pmetric.ExponentialHistogramDataPoint | pmetric.SummaryDataPoint
+	Attributes() pcommon.Map
+}

internal/exp/metrics/identity/strings.go

@@ -0,0 +1,24 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package identity // import "github.com/open-telemetry/opentelemetry-collector-contrib/internal/exp/metrics/identity"
+
+import (
+	"fmt"
+)
+
+func (r Resource) String() string {
+	return fmt.Sprintf("resource/%x", r.Hash().Sum64())
+}
+
+func (s Scope) String() string {
+	return fmt.Sprintf("scope/%x", s.Hash().Sum64())
+}
+
+func (m Metric) String() string {
+	return fmt.Sprintf("metric/%x", m.Hash().Sum64())
+}
+
+func (s Stream) String() string {
+	return fmt.Sprintf("stream/%x", s.Hash().Sum64())
+}

internal/exp/metrics/metadata.yaml

@@ -0,0 +1,3 @@
+status:
+  codeowners:
+    active: [sh0rez, RichieSams]

versions.yaml

@@ -116,6 +116,7 @@ module-sets:
       - github.com/open-telemetry/opentelemetry-collector-contrib/internal/common
       - github.com/open-telemetry/opentelemetry-collector-contrib/internal/coreinternal
       - github.com/open-telemetry/opentelemetry-collector-contrib/internal/docker
+      - github.com/open-telemetry/opentelemetry-collector-contrib/internal/exp/metrics
       - github.com/open-telemetry/opentelemetry-collector-contrib/internal/filter
       - github.com/open-telemetry/opentelemetry-collector-contrib/internal/k8sconfig
       - github.com/open-telemetry/opentelemetry-collector-contrib/internal/k8stest