introduce pprofile.AddAttribute helper

pdata/pprofile/attributes.go

@@ -4,6 +4,10 @@
 package pprofile // import "go.opentelemetry.io/collector/pdata/pprofile"
 
 import (
+	"errors"
+	"fmt"
+	"math"
+
 	"go.opentelemetry.io/collector/pdata/pcommon"
 )
 
@@ -26,3 +30,35 @@ func FromAttributeIndices(table AttributeTableSlice, record attributable) pcommo
 
 	return m
 }
+
+// AddAttribute updates an AttributeTable and a record's AttributeIndices to
+// add a new attribute.
+// The record can by any struct that implements an `AttributeIndices` method.
+func AddAttribute(table AttributeTableSlice, record attributable, key string, value any) error {
+	for i := 0; i < table.Len(); i++ {
+		a := table.At(i)
+
+		if a.Key() == key && value == a.Value().AsRaw() {
+			if i >= math.MaxInt32 {
+				return fmt.Errorf("Attribute %s=%#v has too high an indice to be added to AttributeIndices", key, value)
+			}
+
+			record.AttributeIndices().Append(int32(i)) //nolint:gosec // overflow checked
+			return nil
+		}
+	}
+
+	if table.Len() >= math.MaxInt32 {
+		return errors.New("AttributeTable can't take more attributes")
+	}
+	table.EnsureCapacity(table.Len() + 1)
+	entry := table.AppendEmpty()
+	entry.SetKey(key)
+	err := entry.Value().FromRaw(value)
+	if err != nil {
+		return err
+	}
+	record.AttributeIndices().Append(int32(table.Len()) - 1) //nolint:gosec // overflow checked
+
+	return nil
+}

pdata/pprofile/attributes_test.go

@@ -8,6 +8,7 @@ import (
 	"testing"
 
 	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
 
 	"go.opentelemetry.io/collector/pdata/pcommon"
 )
@@ -43,6 +44,29 @@ func TestFromAttributeIndices(t *testing.T) {
 	assert.Equal(t, attrs.AsRaw(), m)
 }
 
+func TestAddAttribute(t *testing.T) {
+	table := NewAttributeTableSlice()
+	att := table.AppendEmpty()
+	att.SetKey("hello")
+	att.Value().SetStr("world")
+
+	// Add a brand new attribute
+	loc := NewLocation()
+	err := AddAttribute(table, loc, "bonjour", "monde")
+	require.NoError(t, err)
+
+	assert.Equal(t, 2, table.Len())
+	assert.Equal(t, []int32{1}, loc.AttributeIndices().AsRaw())
+
+	// Add an already existing attribute
+	mapp := NewMapping()
+	err = AddAttribute(table, mapp, "hello", "world")
+	require.NoError(t, err)
+
+	assert.Equal(t, 2, table.Len())
+	assert.Equal(t, []int32{0}, mapp.AttributeIndices().AsRaw())
+}
+
 func BenchmarkFromAttributeIndices(b *testing.B) {
 	table := NewAttributeTableSlice()
 
@@ -62,3 +86,63 @@ func BenchmarkFromAttributeIndices(b *testing.B) {
 		_ = FromAttributeIndices(table, obj)
 	}
 }
+
+func BenchmarkAddAttribute(b *testing.B) {
+	for _, bb := range []struct {
+		name  string
+		key   string
+		value any
+
+		runBefore func(*testing.B, AttributeTableSlice)
+	}{
+		{
+			name:  "with a new string attribute",
+			key:   "attribute",
+			value: "test",
+		},
+		{
+			name:  "with an existing attribute",
+			key:   "attribute",
+			value: "test",
+
+			runBefore: func(_ *testing.B, table AttributeTableSlice) {
+				entry := table.AppendEmpty()
+				entry.SetKey("attribute")
+				entry.Value().SetStr("test")
+			},
+		},
+		{
+			name:  "with a hundred attributes to loop through",
+			key:   "attribute",
+			value: "test",
+
+			runBefore: func(_ *testing.B, table AttributeTableSlice) {
+				for i := range 100 {
+					entry := table.AppendEmpty()
+					entry.SetKey(fmt.Sprintf("attr_%d", i))
+					entry.Value().SetStr("test")
+				}
+
+				entry := table.AppendEmpty()
+				entry.SetKey("attribute")
+				entry.Value().SetStr("test")
+			},
+		},
+	} {
+		b.Run(bb.name, func(b *testing.B) {
+			table := NewAttributeTableSlice()
+			obj := NewLocation()
+
+			if bb.runBefore != nil {
+				bb.runBefore(b, table)
+			}
+
+			b.ResetTimer()
+			b.ReportAllocs()
+
+			for n := 0; n < b.N; n++ {
+				_ = AddAttribute(table, obj, bb.key, bb.value)
+			}
+		})
+	}
+}