Generate marshal JSON without gogo proto jsonpb

.chloggen/gen-marshal-json-stream.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: Use pdatagen to generate marshalJSON without using gogo proto jsonpb.
+
+# One or more tracking issues or pull requests related to the change
+issues: [13450]
+
+# (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/message_field.go

@@ -39,6 +39,15 @@ const messageSetTestTemplate = `{{ if .isCommon -}}
 const messageCopyOrigTemplate = `{{ if .isCommon }}{{ if not .isBaseStructCommon }}internal.{{ end }}CopyOrig{{ else }}copyOrig{{ end }}
 {{- .returnType }}(&dest.{{ .originFieldName }}, &src.{{ .originFieldName }})`
 
+const messageMarshalJSONTemplate = `{{- if eq .returnType "TraceState" }} if ms.orig.{{ .originFieldName }} != "" { {{ end -}}
+	dest.WriteObjectField("{{ lowerFirst .originFieldName }}")
+	{{- if .isCommon }}
+	{{ if not .isBaseStructCommon }}internal.{{ end }}MarshalJSONStream{{ .returnType }}(
+	{{- if not .isBaseStructCommon }}internal.{{ end }}New{{ .returnType }}(&ms.orig.{{ .originFieldName }}, ms.state), dest)
+	{{- else }}
+	ms.{{ .fieldName }}().marshalJSONStream(dest)
+	{{- end }}{{ if eq .returnType "TraceState" -}} } {{- end }}`
+
 type MessageField struct {
 	fieldName     string
 	returnMessage *messageStruct
@@ -64,6 +73,11 @@ func (mf *MessageField) GenerateCopyOrig(ms *messageStruct) string {
 	return executeTemplate(t, mf.templateFields(ms))
 }
 
+func (mf *MessageField) GenerateMarshalJSON(ms *messageStruct) string {
+	t := template.Must(templateNew("messageMarshalJSONTemplate").Parse(messageMarshalJSONTemplate))
+	return executeTemplate(t, mf.templateFields(ms))
+}
+
 func (mf *MessageField) templateFields(ms *messageStruct) map[string]any {
 	return map[string]any{
 		"isCommon":        usedByOtherDataTypes(mf.returnMessage.packageName),

internal/cmd/pdatagen/internal/one_of_field.go

@@ -39,6 +39,12 @@ const oneOfCopyOrigTemplate = `switch t := src.{{ .originFieldName }}.(type) {
 {{- end }}
 }`
 
+const oneOfMarshalJSONTemplate = `switch ov := ms.{{ .origAccessor }}.{{ .originFieldName }}.(type) {
+		{{- range .values }}
+		{{ .GenerateMarshalJSON $.baseStruct $.OneOfField }}
+		{{- end }}
+	}`
+
 type OneOfField struct {
 	originFieldName            string
 	typeName                   string
@@ -74,6 +80,11 @@ func (of *OneOfField) GenerateCopyOrig(ms *messageStruct) string {
 	return executeTemplate(t, of.templateFields(ms))
 }
 
+func (of *OneOfField) GenerateMarshalJSON(ms *messageStruct) string {
+	t := template.Must(templateNew("oneOfMarshalJSONTemplate").Parse(oneOfMarshalJSONTemplate))
+	return executeTemplate(t, of.templateFields(ms))
+}
+
 func (of *OneOfField) templateFields(ms *messageStruct) map[string]any {
 	return map[string]any{
 		"baseStruct":           ms,
@@ -99,4 +110,5 @@ type oneOfValue interface {
 	GenerateSetWithTestValue(ms *messageStruct, of *OneOfField) string
 	GenerateCopyOrig(ms *messageStruct, of *OneOfField) string
 	GenerateType(ms *messageStruct, of *OneOfField) string
+	GenerateMarshalJSON(ms *messageStruct, of *OneOfField) string
 }

internal/cmd/pdatagen/internal/one_of_message_value.go

@@ -68,6 +68,10 @@ const oneOfMessageCopyOrigTemplate = `	case *{{ .originStructType }}:
 const oneOfMessageTypeTemplate = `case *{{ .originStructName }}_{{ .originFieldName }}:
 	return {{ .typeName }}`
 
+const oneOfMessageMarshalJSONTemplate = `case *{{ .originStructName }}_{{ .originFieldName }}:
+	dest.WriteObjectField("{{ lowerFirst .originFieldName }}")
+	new{{ .returnType }}(ov.{{ .fieldName }}, ms.state).marshalJSONStream(dest)`
+
 type OneOfMessageValue struct {
 	fieldName              string
 	originFieldPackageName string
@@ -99,6 +103,11 @@ func (omv *OneOfMessageValue) GenerateType(ms *messageStruct, of *OneOfField) st
 	return executeTemplate(t, omv.templateFields(ms, of))
 }
 
+func (omv *OneOfMessageValue) GenerateMarshalJSON(ms *messageStruct, of *OneOfField) string {
+	t := template.Must(templateNew("oneOfMessageMarshalJSONTemplate").Parse(oneOfMessageMarshalJSONTemplate))
+	return executeTemplate(t, omv.templateFields(ms, of))
+}
+
 func (omv *OneOfMessageValue) templateFields(ms *messageStruct, of *OneOfField) map[string]any {
 	return map[string]any{
 		"fieldName":               omv.fieldName,

internal/cmd/pdatagen/internal/one_of_primitive_value.go

@@ -54,6 +54,10 @@ const oneOfPrimitiveCopyOrigTemplate = `case *{{ .originStructName }}_{{ .origin
 const oneOfPrimitiveTypeTemplate = `case *{{ .originStructName }}_{{ .originFieldName }}:
 	return {{ .typeName }}`
 
+const oneOfPrimitiveMarshalJSONTemplate = `case *{{ .originStructName }}_{{ .originFieldName }}:
+	dest.WriteObjectField("{{ lowerFirst .originFieldName }}")
+	dest.Write{{ upperFirst .returnType }}(ov.{{ .originFieldName }})`
+
 type OneOfPrimitiveValue struct {
 	fieldName       string
 	defaultVal      string
@@ -87,6 +91,11 @@ func (opv *OneOfPrimitiveValue) GenerateType(ms *messageStruct, of *OneOfField)
 	return executeTemplate(t, opv.templateFields(ms, of))
 }
 
+func (opv *OneOfPrimitiveValue) GenerateMarshalJSON(ms *messageStruct, of *OneOfField) string {
+	t := template.Must(templateNew("oneOfPrimitiveMarshalJSONTemplate").Parse(oneOfPrimitiveMarshalJSONTemplate))
+	return executeTemplate(t, opv.templateFields(ms, of))
+}
+
 func (opv *OneOfPrimitiveValue) templateFields(ms *messageStruct, of *OneOfField) map[string]any {
 	return map[string]any{
 		"structName":  ms.getName(),

internal/cmd/pdatagen/internal/optional_primitive_field.go

@@ -67,6 +67,11 @@ const optionalPrimitiveCopyOrigTemplate = `if src{{ .fieldName }}, ok := src.{{
 	dest.{{ .fieldName }}_ = nil
 }`
 
+const optionalPrimitiveMarshalJSONTemplate = `if ms.Has{{ .fieldName }}() {
+		dest.WriteObjectField("{{ lowerFirst .fieldName }}")
+		dest.Write{{ upperFirst .returnType }}(ms.{{ .fieldName }}())
+	}`
+
 type OptionalPrimitiveField struct {
 	fieldName  string
 	defaultVal string
@@ -94,6 +99,11 @@ func (opv *OptionalPrimitiveField) GenerateCopyOrig(ms *messageStruct) string {
 	return executeTemplate(t, opv.templateFields(ms))
 }
 
+func (opv *OptionalPrimitiveField) GenerateMarshalJSON(ms *messageStruct) string {
+	t := template.Must(templateNew("optionalPrimitiveMarshalJSONTemplate").Parse(optionalPrimitiveMarshalJSONTemplate))
+	return executeTemplate(t, opv.templateFields(ms))
+}
+
 func (opv *OptionalPrimitiveField) templateFields(ms *messageStruct) map[string]any {
 	return map[string]any{
 		"structName":       ms.getName(),

internal/cmd/pdatagen/internal/primitive_field.go

@@ -48,6 +48,11 @@ const primitiveSetTestTemplate = `tv.orig.{{ .originFieldName }} = {{ .testValue
 
 const primitiveCopyOrigTemplate = `dest.{{ .originFieldName }} = src.{{ .originFieldName }}`
 
+const primitiveMarshalJSONTemplate = `if ms.orig.{{ .originFieldName }} != {{ .defaultVal }} {
+		dest.WriteObjectField("{{ lowerFirst .originFieldName }}")
+		dest.Write{{ upperFirst .returnType }}(ms.orig.{{ .originFieldName }})
+	}`
+
 type PrimitiveField struct {
 	fieldName       string
 	originFieldName string
@@ -76,6 +81,11 @@ func (pf *PrimitiveField) GenerateCopyOrig(ms *messageStruct) string {
 	return executeTemplate(t, pf.templateFields(ms))
 }
 
+func (pf *PrimitiveField) GenerateMarshalJSON(ms *messageStruct) string {
+	t := template.Must(templateNew("primitiveMarshalJSONTemplate").Parse(primitiveMarshalJSONTemplate))
+	return executeTemplate(t, pf.templateFields(ms))
+}
+
 func (pf *PrimitiveField) templateFields(ms *messageStruct) map[string]any {
 	return map[string]any{
 		"structName":       ms.getName(),

internal/cmd/pdatagen/internal/primitive_slice_field.go

@@ -26,6 +26,14 @@ const primitiveSliceCopyOrigTemplate = `dest.{{ .originFieldName }} =
 {{- if .isCommon }}{{ if not .isBaseStructCommon }}internal.{{ end }}CopyOrig{{ else }}copyOrig{{ end }}
 {{- .returnType }}(dest.{{ .originFieldName }}, src.{{ .originFieldName }})`
 
+const primitiveSliceMarshalJSONTemplate = `dest.WriteObjectField("{{ lowerFirst .originFieldName }}")
+	{{- if .isCommon }}
+	{{ if not .isBaseStructCommon }}internal.{{ end }}MarshalJSONStream{{ .returnType }}(
+	{{- if not .isBaseStructCommon }}internal.{{ end }}New{{ .returnType }}(&ms.orig.{{ .originFieldName }}, ms.state), dest)
+	{{- else }}
+	ms.{{ .fieldName }}().marshalJSONStream(dest)
+	{{- end }}`
+
 // PrimitiveSliceField is used to generate fields for slice of primitive types
 type PrimitiveSliceField struct {
 	fieldName         string
@@ -56,6 +64,11 @@ func (psf *PrimitiveSliceField) GenerateCopyOrig(ms *messageStruct) string {
 	return executeTemplate(t, psf.templateFields(ms))
 }
 
+func (psf *PrimitiveSliceField) GenerateMarshalJSON(ms *messageStruct) string {
+	t := template.Must(templateNew("primitiveSliceMarshalJSONTemplate").Parse(primitiveSliceMarshalJSONTemplate))
+	return executeTemplate(t, psf.templateFields(ms))
+}
+
 func (psf *PrimitiveSliceField) templateFields(ms *messageStruct) map[string]any {
 	return map[string]any{
 		"structName": ms.getName(),

internal/cmd/pdatagen/internal/slice_field.go

@@ -46,6 +46,16 @@ const sliceCopyOrigTemplate = `dest.{{ .originFieldName }} =
 {{- if .isCommon }}{{ if not .isBaseStructCommon }}internal.{{ end }}CopyOrig{{ else }}copyOrig{{ end }}
 {{- .returnType }}(dest.{{ .originFieldName }}, src.{{ .originFieldName }})`
 
+const sliceMarshalJSONTemplate = `if len(ms.orig.{{ .originFieldName }}) > 0 {
+		dest.WriteObjectField("{{ lowerFirst .originFieldName }}")
+		{{- if .isCommon }}
+		{{ if not .isBaseStructCommon }}internal.{{ end }}MarshalJSONStream{{ .returnType }}(
+		{{- if not .isBaseStructCommon }}internal.{{ end }}New{{ .returnType }}(&ms.orig.{{ .originFieldName }}, ms.state), dest)
+		{{- else }}
+		ms.{{ .fieldName }}().marshalJSONStream(dest)
+		{{- end }}
+	}`
+
 type SliceField struct {
 	fieldName       string
 	originFieldName string
@@ -79,6 +89,11 @@ func (sf *SliceField) GenerateCopyOrig(ms *messageStruct) string {
 	return executeTemplate(t, sf.templateFields(ms))
 }
 
+func (sf *SliceField) GenerateMarshalJSON(ms *messageStruct) string {
+	t := template.Must(templateNew("sliceMarshalJSONTemplate").Parse(sliceMarshalJSONTemplate))
+	return executeTemplate(t, sf.templateFields(ms))
+}
+
 func (sf *SliceField) templateFields(ms *messageStruct) map[string]any {
 	return map[string]any{
 		"structName": ms.getName(),

internal/cmd/pdatagen/internal/templates/message.go.tmpl

@@ -7,9 +7,9 @@
 package {{ .packageName }}
 
 import (
-{{ range $index, $element := .imports -}}
-{{ $element }}
-{{ end }}
+	{{ range $index, $element := .imports -}}
+	{{ $element }}
+	{{ end }}
 )
 
 {{ .description }}
@@ -81,6 +81,15 @@ func (ms {{ .structName }}) getState() *internal.State {
 	return internal.Get{{ .structName }}State(internal.{{ .structName }}(ms))
 }
 {{- else }}
+// marshalJSONStream marshals all properties from the current struct to the destination stream.
+func (ms {{ .structName }}) marshalJSONStream(dest *json.Stream) {
+	dest.WriteObjectStart()
+	{{ range .fields -}}
+	{{ .GenerateMarshalJSON $.messageStruct }}
+	{{ end -}}
+	dest.WriteObjectEnd()
+}
+
 func copyOrig{{ .structName }}(dest, src *{{ .originName }}) {
 	{{- range .fields }}
 	{{ .GenerateCopyOrig $.messageStruct }}

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

@@ -7,11 +7,11 @@
 package internal
 
 import (
-{{ range $index, $element := .imports -}}
-{{ if ne $element "go.opentelemetry.io/collector/pdata/internal" }}
-{{ $element }}
-{{ end }}
-{{ end }}
+	{{ range $index, $element := .imports -}}
+	{{ if ne $element "go.opentelemetry.io/collector/pdata/internal" }}
+	{{ $element }}
+	{{- end }}
+	{{- end }}
 )
 
 type {{ .structName }} struct {
@@ -50,3 +50,12 @@ func FillTest{{ .structName }}(tv {{ .structName }}) {
 	{{ .GenerateSetWithTestValue $.messageStruct }}
 	{{- end }}
 }
+
+// MarshalJSONStream marshals all properties from the current struct to the destination stream.
+func MarshalJSONStream{{ .structName }}(ms {{ .structName }}, dest *json.Stream) {
+	dest.WriteObjectStart()
+	{{ range .fields -}}
+	{{ .GenerateMarshalJSON $.messageStruct }}
+	{{ end -}}
+	dest.WriteObjectEnd()
+}

internal/cmd/pdatagen/internal/templates/message_test.go.tmpl

@@ -7,9 +7,9 @@
 package {{ .packageName }}
 
 import (
-{{ range $index, $element := .testImports -}}
-{{ $element }}
-{{ end }}
+	{{ range $index, $element := .testImports -}}
+	{{ $element }}
+	{{ end }}
 )
 
 func Test{{ .structName }}_MoveTo(t *testing.T) {
@@ -37,6 +37,28 @@ func Test{{ .structName }}_CopyTo(t *testing.T) {
 	assert.Panics(t, func() { ms.CopyTo(new{{ .structName }}(&{{ .originName }}{}, &sharedState)) })
 }
 
+func Test{{ .structName }}_MarshalAndUnmarshal(t *testing.T) {
+	stream := json.BorrowStream(nil)
+	defer json.ReturnStream(stream)
+	src := generateTest{{ .structName }}()
+	{{- if .isCommon }}
+	internal.MarshalJSONStream{{ .structName }}(internal.{{ .structName }}(src), stream)
+	{{- else }}
+	src.marshalJSONStream(stream)
+	{{- end }}
+
+	iter := json.BorrowIterator(stream.Buffer())
+	defer json.ReturnIterator(iter)
+	dest := New{{ .structName }}()
+	{{- if .isCommon }}
+	internal.UnmarshalJSONIter{{ .structName }}(internal.{{ .structName }}(dest), iter)
+	{{- else }}
+	dest.unmarshalJsoniter(iter)
+	{{- end }}
+
+	assert.Equal(t, src, dest)
+}
+
 {{ range .fields }}
 {{ .GenerateAccessorsTest $.messageStruct }}
 {{ end }}

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

@@ -7,9 +7,9 @@
 package {{ .packageName }}
 
 import (
-{{ range $index, $element := .imports -}}
-{{ $element }}
-{{ end }}
+	{{ range $index, $element := .imports -}}
+	{{ $element }}
+	{{ end }}
 )
 
 // {{ .structName }} represents a []{{ .itemType }} slice.

internal/cmd/pdatagen/internal/templates/primitive_slice_internal.go.tmpl

@@ -7,11 +7,11 @@
 package internal
 
 import (
-{{ range $index, $element := .imports -}}
-{{ if ne $element "go.opentelemetry.io/collector/pdata/internal" }}
-{{ $element }}
-{{ end }}
-{{ end }}
+	{{ range $index, $element := .imports -}}
+	{{ if ne $element "go.opentelemetry.io/collector/pdata/internal" }}
+	{{ $element }}
+	{{- end }}
+	{{- end }}
 )
 
 type {{ .structName }} struct {
@@ -47,3 +47,20 @@ func GenerateTest{{ .structName }}() {{ .structName }} {
 	FillTest{{ .structName }}(ms)
 	return ms
 }
+
+// MarshalJSONStream marshals all properties from the current struct to the destination stream.
+func MarshalJSONStream{{ .structName }}(ms {{ .structName }}, dest *json.Stream) {
+	{{- if eq .itemType "byte" }}
+	dest.WriteString(base64.StdEncoding.EncodeToString(*ms.orig))
+	{{- else }}
+	dest.WriteArrayStart()
+	if len(*ms.orig) > 0 {
+		dest.Write{{ upperFirst .itemType }}((*ms.orig)[0])
+	}
+	for i := 1; i < len((*ms.orig)); i++ {
+		dest.WriteMore()
+		dest.Write{{ upperFirst .itemType }}((*ms.orig)[i])
+	}
+	dest.WriteArrayEnd()
+	{{- end }}
+}

internal/cmd/pdatagen/internal/templates/primitive_slice_test.go.tmpl

@@ -7,9 +7,9 @@
 package {{ .packageName }}
 
 import (
-{{ range $index, $element := .testImports -}}
-{{ $element }}
-{{ end }}
+	{{ range $index, $element := .testImports -}}
+	{{ $element }}
+	{{ end }}
 )
 
 func TestNew{{ .structName }}(t *testing.T) {