Add MergeTo method for profiles

Signed-off-by: Israel Blancas <[email protected]>

Author: iblancasa

pdata/pprofile/profiles_merge.go

@@ -0,0 +1,24 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package pprofile // import "go.opentelemetry.io/collector/pdata/pprofile"
+
+// MergeTo merges the current Profiles into dest, updating the destination
+// dictionary as needed and appending the resource profiles.
+// The source Profiles is consumed and marked read-only after this operation.
+func (ms Profiles) MergeTo(dest Profiles) error {
+	ms.getState().AssertMutable()
+	dest.getState().AssertMutable()
+	if ms.getOrig() == dest.getOrig() {
+		return nil
+	}
+
+	if err := ms.switchDictionary(ms.Dictionary(), dest.Dictionary()); err != nil {
+		return err
+	}
+
+	ms.ResourceProfiles().MoveAndAppendTo(dest.ResourceProfiles())
+	ms.MarkReadOnly()
+
+	return nil
+}

pdata/pprofile/profiles_merge_test.go

@@ -0,0 +1,62 @@
+// Copyright The OpenTelemetry Authors
+// SPDX-License-Identifier: Apache-2.0
+
+package pprofile
+
+import (
+	"testing"
+
+	"github.com/stretchr/testify/assert"
+	"github.com/stretchr/testify/require"
+)
+
+func TestProfilesMergeTo(t *testing.T) {
+	src := NewProfiles()
+	dest := NewProfiles()
+
+	src.ResourceProfiles().AppendEmpty()
+	src.ResourceProfiles().AppendEmpty()
+	dest.ResourceProfiles().AppendEmpty()
+
+	require.NoError(t, src.MergeTo(dest))
+
+	assert.Equal(t, 3, dest.ResourceProfiles().Len())
+	assert.Equal(t, 0, src.ResourceProfiles().Len())
+	assert.True(t, src.IsReadOnly())
+}
+
+func TestProfilesMergeToSelf(t *testing.T) {
+	profiles := NewProfiles()
+	profiles.Dictionary().StringTable().Append("test")
+	profiles.ResourceProfiles().AppendEmpty()
+
+	require.NoError(t, profiles.MergeTo(profiles))
+
+	assert.Equal(t, 1, profiles.Dictionary().StringTable().Len())
+	assert.Equal(t, 1, profiles.ResourceProfiles().Len())
+}
+
+func TestProfilesMergeToError(t *testing.T) {
+	src := NewProfiles()
+	dest := NewProfiles()
+
+	stackTable := src.Dictionary().StackTable()
+	stackTable.AppendEmpty()
+	stack := stackTable.AppendEmpty()
+	stack.LocationIndices().Append(1)
+
+	locationTable := src.Dictionary().LocationTable()
+	locationTable.AppendEmpty()
+	locationTable.AppendEmpty().SetMappingIndex(1)
+
+	sample := src.ResourceProfiles().AppendEmpty().
+		ScopeProfiles().AppendEmpty().
+		Profiles().AppendEmpty().
+		Samples().AppendEmpty()
+	sample.SetStackIndex(1)
+
+	err := src.MergeTo(dest)
+	require.Error(t, err)
+
+	assert.Equal(t, 0, dest.ResourceProfiles().Len())
+}