[chore] add profiles support to the golden package (open-telemetry#39473)

#### Description

This adds profiles support to the `pkg/golden` package, so other
modules, such as `countconnector` can use it.

Author: dmathieu

internal/exp/metrics/go.mod

@@ -19,6 +19,7 @@ require (
 	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
 	github.com/modern-go/reflect2 v1.0.2 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
+	go.opentelemetry.io/collector/pdata/pprofile v0.124.0 // indirect
 	go.uber.org/multierr v1.11.0 // indirect
 	golang.org/x/net v0.38.0 // indirect
 	golang.org/x/sys v0.31.0 // indirect

internal/exp/metrics/go.sum

@@ -2,7 +2,7 @@
 <!-- status autogenerated section -->
 | Status        |           |
 | ------------- |-----------|
-| Stability     | [alpha]: traces, metrics, logs   |
+| Stability     | [alpha]: traces, metrics, logs, profiles   |
 | Issues        | [![Open issues](https://img.shields.io/github/issues-search/open-telemetry/opentelemetry-collector-contrib?query=is%3Aissue%20is%3Aopen%20label%3Apkg%2Fgolden%20&label=open&color=orange&logo=opentelemetry)](https://github.com/open-telemetry/opentelemetry-collector-contrib/issues?q=is%3Aopen+is%3Aissue+label%3Apkg%2Fgolden) [![Closed issues](https://img.shields.io/github/issues-search/open-telemetry/opentelemetry-collector-contrib?query=is%3Aissue%20is%3Aclosed%20label%3Apkg%2Fgolden%20&label=closed&color=blue&logo=opentelemetry)](https://github.com/open-telemetry/opentelemetry-collector-contrib/issues?q=is%3Aclosed+is%3Aissue+label%3Apkg%2Fgolden) |
 | [Code Owners](https://github.com/open-telemetry/opentelemetry-collector-contrib/blob/main/CONTRIBUTING.md#becoming-a-code-owner)    | [@djaglowski](https://www.github.com/djaglowski), [@atoulme](https://www.github.com/atoulme) |
 

internal/pdatautil/go.sum

@@ -6,6 +6,7 @@ require (
 	github.com/open-telemetry/opentelemetry-collector-contrib/pkg/pdatautil v0.124.1
 	github.com/stretchr/testify v1.10.0
 	go.opentelemetry.io/collector/pdata v1.30.0
+	go.opentelemetry.io/collector/pdata/pprofile v0.124.0
 	go.uber.org/goleak v1.3.0
 	gopkg.in/yaml.v3 v3.0.1
 )
@@ -18,6 +19,7 @@ require (
 	github.com/modern-go/concurrent v0.0.0-20180306012644-bacd9c7ef1dd // indirect
 	github.com/modern-go/reflect2 v1.0.2 // indirect
 	github.com/pmezard/go-difflib v1.0.0 // indirect
+	github.com/rogpeppe/go-internal v1.13.1 // indirect
 	go.uber.org/multierr v1.11.0 // indirect
 	golang.org/x/net v0.38.0 // indirect
 	golang.org/x/sys v0.31.0 // indirect

pkg/golden/README.md

@@ -12,6 +12,7 @@ import (
 
 	"go.opentelemetry.io/collector/pdata/plog"
 	"go.opentelemetry.io/collector/pdata/pmetric"
+	"go.opentelemetry.io/collector/pdata/pprofile"
 	"go.opentelemetry.io/collector/pdata/ptrace"
 	"gopkg.in/yaml.v3"
 )
@@ -190,3 +191,54 @@ func writeTraces(filePath string, traces ptrace.Traces) error {
 	}
 	return os.WriteFile(filePath, b.Bytes(), 0o600)
 }
+
+// ReadProfiles reads a pprofile.Profiles from the specified YAML or JSON file.
+func ReadProfiles(filePath string) (pprofile.Profiles, error) {
+	b, err := os.ReadFile(filePath)
+	if err != nil {
+		return pprofile.Profiles{}, err
+	}
+	if strings.HasSuffix(filePath, ".yaml") || strings.HasSuffix(filePath, ".yml") {
+		var m map[string]any
+		if err = yaml.Unmarshal(b, &m); err != nil {
+			return pprofile.Profiles{}, err
+		}
+		b, err = json.Marshal(m)
+		if err != nil {
+			return pprofile.Profiles{}, err
+		}
+	}
+	unmarshaler := pprofile.JSONUnmarshaler{}
+	return unmarshaler.UnmarshalProfiles(b)
+}
+
+// WriteProfiles writes a pprofile.Profiles to the specified file in YAML format.
+func WriteProfiles(tb testing.TB, filePath string, profiles pprofile.Profiles) error {
+	if err := writeProfiles(filePath, profiles); err != nil {
+		return err
+	}
+	tb.Logf("Golden file successfully written to %s.", filePath)
+	tb.Log("NOTE: The WriteProfiles call must be removed in order to pass the test.")
+	tb.Fail()
+	return nil
+}
+
+// writeProfiles writes a pprofile.Profiles to the specified file in YAML format.
+func writeProfiles(filePath string, profiles pprofile.Profiles) error {
+	unmarshaler := &pprofile.JSONMarshaler{}
+	fileBytes, err := unmarshaler.MarshalProfiles(profiles)
+	if err != nil {
+		return err
+	}
+	var jsonVal map[string]any
+	if err = json.Unmarshal(fileBytes, &jsonVal); err != nil {
+		return err
+	}
+	b := &bytes.Buffer{}
+	enc := yaml.NewEncoder(b)
+	enc.SetIndent(2)
+	if err := enc.Encode(jsonVal); err != nil {
+		return err
+	}
+	return os.WriteFile(filePath, b.Bytes(), 0o600)
+}

pkg/golden/go.mod

@@ -16,6 +16,7 @@ import (
 	"go.opentelemetry.io/collector/pdata/pcommon"
 	"go.opentelemetry.io/collector/pdata/plog"
 	"go.opentelemetry.io/collector/pdata/pmetric"
+	"go.opentelemetry.io/collector/pdata/pprofile"
 	"go.opentelemetry.io/collector/pdata/ptrace"
 )
 
@@ -323,3 +324,85 @@ func TestSortAndNormalizeMetrics(t *testing.T) {
 
 	require.Equal(t, before, after)
 }
+
+func TestReadProfiles(t *testing.T) {
+	expectedProfiles := CreateTestProfiles()
+
+	expectedFile := filepath.Join("testdata", "profiles-roundtrip", "expected.yaml")
+	actualProfiles, err := ReadProfiles(expectedFile)
+	require.NoError(t, err)
+	require.Equal(t, expectedProfiles, actualProfiles)
+}
+
+func TestWriteProfiles(t *testing.T) {
+	profiles := CreateTestProfiles()
+
+	actualFile := filepath.Join(t.TempDir(), "profiles.yaml")
+	require.NoError(t, writeProfiles(actualFile, profiles))
+
+	actualBytes, err := os.ReadFile(actualFile)
+	require.NoError(t, err)
+
+	expectedFile := filepath.Join("testdata", "profiles-roundtrip", "expected.yaml")
+	expectedBytes, err := os.ReadFile(expectedFile)
+	require.NoError(t, err)
+
+	if runtime.GOOS == "windows" {
+		// os.ReadFile adds a '\r' that we don't actually expect
+		expectedBytes = bytes.ReplaceAll(expectedBytes, []byte("\r\n"), []byte("\n"))
+	}
+
+	require.Equal(t, expectedBytes, actualBytes)
+}
+
+func TestProfilesRoundTrip(t *testing.T) {
+	expectedProfiles := CreateTestProfiles()
+
+	tempDir := filepath.Join(t.TempDir(), "profiles.yaml")
+	require.NoError(t, writeProfiles(tempDir, expectedProfiles))
+
+	actualProfiles, err := ReadProfiles(tempDir)
+	require.NoError(t, err)
+	require.Equal(t, expectedProfiles, actualProfiles)
+}
+
+func CreateTestProfiles() pprofile.Profiles {
+	profiles := pprofile.NewProfiles()
+	resource := profiles.ResourceProfiles().AppendEmpty()
+	scope := resource.ScopeProfiles().AppendEmpty()
+	profile := scope.Profiles().AppendEmpty()
+
+	profile.StringTable().Append("samples", "count", "cpu", "nanoseconds")
+	st := profile.SampleType().AppendEmpty()
+	st.SetTypeStrindex(0)
+	st.SetUnitStrindex(1)
+	pt := profile.PeriodType()
+	pt.SetTypeStrindex(2)
+	pt.SetUnitStrindex(3)
+
+	a := profile.AttributeTable().AppendEmpty()
+	a.SetKey("process.executable.build_id.htlhash")
+	a.Value().SetStr("600DCAFE4A110000F2BF38C493F5FB92")
+	a = profile.AttributeTable().AppendEmpty()
+	a.SetKey("profile.frame.type")
+	a.Value().SetStr("native")
+	a = profile.AttributeTable().AppendEmpty()
+	a.SetKey("host.id")
+	a.Value().SetStr("localhost")
+
+	profile.AttributeIndices().Append(2)
+
+	sample := profile.Sample().AppendEmpty()
+	sample.TimestampsUnixNano().Append(0)
+	sample.SetLocationsLength(1)
+
+	m := profile.MappingTable().AppendEmpty()
+	m.AttributeIndices().Append(0)
+
+	l := profile.LocationTable().AppendEmpty()
+	l.SetMappingIndex(0)
+	l.SetAddress(111)
+	l.AttributeIndices().Append(1)
+
+	return profiles
+}

pkg/golden/go.sum

@@ -3,6 +3,6 @@ type: golden
 status:
   class: pkg
   stability:
-    alpha: [ traces, metrics, logs ]
+    alpha: [ traces, metrics, logs, profiles ]
   codeowners:
-    active: [djaglowski, atoulme]
+    active: [djaglowski, atoulme]

pkg/golden/golden.go

@@ -0,0 +1,40 @@
+resourceProfiles:
+  - resource: {}
+    scopeProfiles:
+      - profiles:
+          - attributeIndices:
+              - 2
+            attributeTable:
+              - key: process.executable.build_id.htlhash
+                value:
+                  stringValue: 600DCAFE4A110000F2BF38C493F5FB92
+              - key: profile.frame.type
+                value:
+                  stringValue: native
+              - key: host.id
+                value:
+                  stringValue: localhost
+            locationTable:
+              - address: "111"
+                attributeIndices:
+                  - 1
+                mappingIndex: 0
+            mappingTable:
+              - attributeIndices:
+                  - 0
+            periodType:
+              typeStrindex: 2
+              unitStrindex: 3
+            profileId: ""
+            sample:
+              - locationsLength: 1
+                timestampsUnixNano:
+                  - "0"
+            sampleType:
+              - unitStrindex: 1
+            stringTable:
+              - samples
+              - count
+              - cpu
+              - nanoseconds
+        scope: {}