Add pprofile aggregation temporality constants (#12253)

This adds constants to more easily use the aggregation temporality enum
in pprofile.

This behavior is very similar to how pmetrics handles those constants.
See
https://pkg.go.dev/go.opentelemetry.io/collector/pdata/pmetric#pkg-constants

cc @rockdaboot

.chloggen/pprofile-aggregation-constants.yaml

@@ -0,0 +1,25 @@
+# Use this changelog template to create an entry for release notes.
+
+# One of 'breaking', 'deprecation', 'new_component', 'enhancement', 'bug_fix'
+change_type: enhancement
+
+# The name of the component, or a single word describing the area of concern, (e.g. otlpreceiver)
+component: pdata/pprofile
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Introduce aggregation temporality constants
+
+# One or more tracking issues or pull requests related to the change
+issues: [12253]
+
+# (Optional) One or more lines of additional information to render under the primary note.
+# These lines will be padded with 2 spaces and then inserted directly into the document.
+# Use pipe (|) for multiline entries.
+subtext:
+
+# Optional: The change log or logs in which this entry should be included.
+# e.g. '[user]' or '[user, api]'
+# Include 'user' if the change is relevant to end users.
+# Include 'api' if there is a change to a library API.
+# Default: '[user]'
+change_logs: [api]

pdata/internal/cmd/pdatagen/internal/pprofile_package.go

@@ -283,11 +283,14 @@ var valueType = &messageValueStruct{
 			defaultVal: "int32(0)",
 			testVal:    "int32(1)",
 		},
-		&primitiveField{
-			fieldName:  "AggregationTemporality",
-			returnType: "otlpprofiles.AggregationTemporality",
-			defaultVal: "otlpprofiles.AggregationTemporality(0)",
-			testVal:    "otlpprofiles.AggregationTemporality(1)",
+		&primitiveTypedField{
+			fieldName: "AggregationTemporality",
+			returnType: &primitiveType{
+				structName: "AggregationTemporality",
+				rawType:    "otlpprofiles.AggregationTemporality",
+				defaultVal: "otlpprofiles.AggregationTemporality(0)",
+				testVal:    "otlpprofiles.AggregationTemporality(1)",
+			},
 		},
 	},
 }

pdata/pprofile/aggregation_temporality.go

@@ -0,0 +1,35 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package pprofile // import "go.opentelemetry.io/collector/pdata/pprofile"
+
+import (
+	otlpprofiles "go.opentelemetry.io/collector/pdata/internal/data/protogen/profiles/v1development"
+)
+
+// AggregationTemporality specifies the method of aggregating metric values,
+// either DELTA (change since last report) or CUMULATIVE (total since a fixed
+// start time).
+type AggregationTemporality int32
+
+const (
+	// AggregationTemporalityUnspecified is the default AggregationTemporality, it MUST NOT be used.
+	AggregationTemporalityUnspecified = AggregationTemporality(otlpprofiles.AggregationTemporality_AGGREGATION_TEMPORALITY_UNSPECIFIED)
+	// AggregationTemporalityDelta is a AggregationTemporality for a metric aggregator which reports changes since last report time.
+	AggregationTemporalityDelta = AggregationTemporality(otlpprofiles.AggregationTemporality_AGGREGATION_TEMPORALITY_DELTA)
+	// AggregationTemporalityCumulative is a AggregationTemporality for a metric aggregator which reports changes since a fixed start time.
+	AggregationTemporalityCumulative = AggregationTemporality(otlpprofiles.AggregationTemporality_AGGREGATION_TEMPORALITY_CUMULATIVE)
+)
+
+// String returns the string representation of the AggregationTemporality.
+func (at AggregationTemporality) String() string {
+	switch at {
+	case AggregationTemporalityUnspecified:
+		return "Unspecified"
+	case AggregationTemporalityDelta:
+		return "Delta"
+	case AggregationTemporalityCumulative:
+		return "Cumulative"
+	}
+	return ""
+}

pdata/pprofile/aggregation_temporality_test.go

@@ -0,0 +1,17 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package pprofile
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+)
+
+func TestAggregationTemporalityString(t *testing.T) {
+	assert.Equal(t, "Unspecified", AggregationTemporalityUnspecified.String())
+	assert.Equal(t, "Delta", AggregationTemporalityDelta.String())
+	assert.Equal(t, "Cumulative", AggregationTemporalityCumulative.String())
+	assert.Equal(t, "", (AggregationTemporalityCumulative + 1).String())
+}