Optimize CopyTo messages to avoid any copy when same source and destination

.chloggen/copyto-optimize.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
+
+# A brief description of the change.  Surround your text with quotes ("") if it needs to start with a backtick (`).
+note: Optimize CopyTo messages to avoid any copy when same source and destination
+
+# One or more tracking issues or pull requests related to the change
+issues: [13680]
+
+# (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: [user]

internal/cmd/pdatagen/internal/pdata/pcommon_package.go

@@ -25,6 +25,7 @@ var pcommon = &Package{
 			`otlpresource "go.opentelemetry.io/collector/pdata/internal/data/protogen/resource/v1"`,
 		},
 		testImports: []string{
+			`"strconv"`,
 			`"testing"`,
 			``,
 			`"github.com/stretchr/testify/assert"`,

internal/cmd/pdatagen/internal/pdata/plog_package.go

@@ -27,6 +27,7 @@ var plog = &Package{
 			`"go.opentelemetry.io/collector/pdata/pcommon"`,
 		},
 		testImports: []string{
+			`"strconv"`,
 			`"testing"`,
 			`"unsafe"`,
 			``,

internal/cmd/pdatagen/internal/pdata/plogotlp_package.go

@@ -23,6 +23,7 @@ var plogotlp = &Package{
 			`otlpcollectorlogs "go.opentelemetry.io/collector/pdata/internal/data/protogen/collector/logs/v1"`,
 		},
 		testImports: []string{
+			`"strconv"`,
 			`"testing"`,
 			``,
 			`"github.com/stretchr/testify/assert"`,

internal/cmd/pdatagen/internal/pdata/pmetric_package.go

@@ -27,6 +27,7 @@ var pmetric = &Package{
 			`"go.opentelemetry.io/collector/pdata/pcommon"`,
 		},
 		testImports: []string{
+			`"strconv"`,
 			`"testing"`,
 			`"unsafe"`,
 			``,

internal/cmd/pdatagen/internal/pdata/pmetricotlp_package.go

@@ -24,6 +24,7 @@ var pmetricotlp = &Package{
 			`otlpcollectormetrics "go.opentelemetry.io/collector/pdata/internal/data/protogen/collector/metrics/v1"`,
 		},
 		testImports: []string{
+			`"strconv"`,
 			`"testing"`,
 			``,
 			`"github.com/stretchr/testify/assert"`,

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

@@ -28,6 +28,7 @@ var pprofile = &Package{
 			`"go.opentelemetry.io/collector/pdata/pcommon"`,
 		},
 		testImports: []string{
+			`"strconv"`,
 			`"testing"`,
 			`"unsafe"`,
 			``,

internal/cmd/pdatagen/internal/pdata/pprofileotlp_package.go

@@ -23,6 +23,7 @@ var pprofileotlp = &Package{
 			`otlpcollectorprofiles "go.opentelemetry.io/collector/pdata/internal/data/protogen/collector/profiles/v1development"`,
 		},
 		testImports: []string{
+			`"strconv"`,
 			`"testing"`,
 			``,
 			`"github.com/stretchr/testify/assert"`,

internal/cmd/pdatagen/internal/pdata/ptrace_package.go

@@ -27,6 +27,7 @@ var ptrace = &Package{
 			`"go.opentelemetry.io/collector/pdata/pcommon"`,
 		},
 		testImports: []string{
+			`"strconv"`,
 			`"testing"`,
 			`"unsafe"`,
 			``,

internal/cmd/pdatagen/internal/pdata/ptraceotlp_package.go

@@ -24,6 +24,7 @@ var ptraceotlp = &Package{
 			`otlpcollectortrace "go.opentelemetry.io/collector/pdata/internal/data/protogen/collector/trace/v1"`,
 		},
 		testImports: []string{
+			`"strconv"`,
 			`"testing"`,
 			``,
 			`"github.com/stretchr/testify/assert"`,

internal/cmd/pdatagen/internal/pdata/templates/message_internal.go.tmpl

@@ -63,6 +63,11 @@ func DeleteOrig{{ .originName }}(orig *{{ .originFullName }}, nullable bool) {
 }
 
 func CopyOrig{{ .originName }}(dest, src *{{ .originFullName }}) {
+	// If copying to same object, just return.
+	if src == dest {
+		return
+    }
+
 	{{- range .fields }}
 	{{ .GenerateCopyOrig $.messageStruct }}
 	{{- end }}

internal/cmd/pdatagen/internal/pdata/templates/message_internal_test.go.tmpl

@@ -13,13 +13,23 @@ import (
 )
 
 func TestCopyOrig{{ .originName }}(t *testing.T) {
-	src := NewOrig{{ .originName }}()
-	dest := NewOrig{{ .originName }}()
-	CopyOrig{{ .originName }}(dest, src)
-	assert.Equal(t, NewOrig{{ .originName }}(), dest)
-    *src = *GenTestOrig{{ .originName }}()
-	CopyOrig{{ .originName }}(dest, src)
-	assert.Equal(t, src, dest)
+    for name, src := range genTestEncodingValues{{ .originName }}() {
+        for _, pooling := range []bool{true, false} {
+            t.Run(name+"pooling_"+strconv.FormatBool(pooling), func(t *testing.T) {
+                prevPooling := UseProtoPooling.IsEnabled()
+                require.NoError(t, featuregate.GlobalRegistry().Set(UseProtoPooling.ID(), pooling))
+                defer func() {
+                    require.NoError(t, featuregate.GlobalRegistry().Set(UseProtoPooling.ID(), prevPooling))
+                }()
+
+                dest := NewOrig{{ .originName }}()
+                CopyOrig{{ .originName }}(dest, src)
+                assert.Equal(t, src, dest)
+                CopyOrig{{ .originName }}(dest, dest)
+                assert.Equal(t, src, dest)
+            })
+        }
+    }
 }
 
 func TestMarshalAndUnmarshalJSONOrig{{ .originName }}Unknown(t *testing.T) {
@@ -34,7 +44,7 @@ func TestMarshalAndUnmarshalJSONOrig{{ .originName }}Unknown(t *testing.T) {
 func TestMarshalAndUnmarshalJSONOrig{{ .originName }}(t *testing.T) {
 	for name, src := range genTestEncodingValues{{ .originName }}() {
         for _, pooling := range []bool{true, false} {
-            t.Run(name, func(t *testing.T) {
+            t.Run(name+"pooling_"+strconv.FormatBool(pooling), func(t *testing.T) {
                 prevPooling := UseProtoPooling.IsEnabled()
                 require.NoError(t, featuregate.GlobalRegistry().Set(UseProtoPooling.ID(), pooling))
                 defer func() {
@@ -78,7 +88,7 @@ func TestMarshalAndUnmarshalProtoOrig{{ .originName }}Unknown(t *testing.T) {
 func TestMarshalAndUnmarshalProtoOrig{{ .originName }}(t *testing.T) {
 	for name, src := range genTestEncodingValues{{ .originName }}(){
         for _, pooling := range []bool{true, false} {
-            t.Run(name, func(t *testing.T) {
+            t.Run(name+"pooling_"+strconv.FormatBool(pooling), func(t *testing.T) {
                 prevPooling := UseProtoPooling.IsEnabled()
                 require.NoError(t, featuregate.GlobalRegistry().Set(UseProtoPooling.ID(), pooling))
                 defer func() {

internal/cmd/pdatagen/internal/pdata/templates/primitive_slice.go.tmpl

@@ -129,6 +129,9 @@ func (ms {{ .structName }}) MoveAndAppendTo(dest {{ .structName }}) {
 // CopyTo copies all elements from the current slice overriding the destination.
 func (ms {{ .structName }}) CopyTo(dest {{ .structName }}) {
 	dest.getState().AssertMutable()
+	if ms.getOrig() == dest.getOrig() {
+		return
+	}
 	*dest.getOrig() = internal.CopyOrig{{ .elementOriginName }}Slice(*dest.getOrig(), *ms.getOrig())
 }
 

internal/cmd/pdatagen/internal/pdata/templates/slice.go.tmpl

@@ -160,6 +160,9 @@ func (es {{ .structName }}) RemoveIf(f func({{ .elementName }}) bool) {
 // CopyTo copies all elements from the current slice overriding the destination.
 func (es {{ .structName }}) CopyTo(dest {{ .structName }}) {
 	dest.{{ .stateAccessor }}.AssertMutable()
+	if es.{{ .origAccessor }} == dest.{{ .origAccessor }} {
+		return
+	}
 	*dest.{{ .origAccessor }} = internal.CopyOrig{{ .elementOriginName }}Slice(*dest.{{ .origAccessor }}, *es.{{ .origAccessor }})
 }
 

internal/cmd/pdatagen/internal/pdata/templates/slice_test.go.tmpl

@@ -56,6 +56,8 @@ func Test{{ .structName }}_CopyTo(t *testing.T) {
 	src := generateTest{{ .structName }}()
 	src.CopyTo(dest)
 	assert.Equal(t, generateTest{{ .structName }}(), dest)
+    dest.CopyTo(dest)
+    assert.Equal(t, generateTest{{ .structName }}(), dest)
 }
 
 func Test{{ .structName }}_EnsureCapacity(t *testing.T) {