[chore] Change AnyValue proto funcs to be auto-generated by pdatagen (#13693)

Updates
#13631

Signed-off-by: Bogdan Drutu <[email protected]>

Author: bogdandrutu

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

@@ -41,6 +41,7 @@ var pcommon = &Package{
 		},
 	},
 	structs: []baseStruct{
+		anyValueStruct,
 		arrayValueStruct,
 		keyValueListStruct,
 		anyValueSlice,
@@ -94,6 +95,69 @@ var mapStruct = &messageSlice{
 	element:         keyValue,
 }
 
+var anyValue = &messageStruct{
+	structName:     "Value",
+	packageName:    "pcommon",
+	originFullName: "otlpcommon.AnyValue",
+}
+
+// anyValueStruct needs to be different from anyValue because otherwise we cause initialization circular deps with mapStruct.
+var anyValueStruct = &messageStruct{
+	structName:     "Value",
+	originFullName: "otlpcommon.AnyValue",
+	fields: []Field{
+		&OneOfField{
+			typeName:                   "MetricType",
+			originFieldName:            "Value",
+			testValueIdx:               1, //
+			omitOriginFieldNameInNames: true,
+			values: []oneOfValue{
+				&OneOfPrimitiveValue{
+					fieldName:       "StringValue",
+					protoID:         1,
+					originFieldName: "StringValue",
+					protoType:       proto.TypeString,
+				},
+				&OneOfPrimitiveValue{
+					fieldName:       "BoolValue",
+					protoID:         2,
+					originFieldName: "BoolValue",
+					protoType:       proto.TypeBool,
+				},
+				&OneOfPrimitiveValue{
+					fieldName:       "IntValue",
+					protoID:         3,
+					originFieldName: "IntValue",
+					protoType:       proto.TypeInt64,
+				},
+				&OneOfPrimitiveValue{
+					fieldName:       "DoubleValue",
+					protoID:         4,
+					originFieldName: "DoubleValue",
+					protoType:       proto.TypeDouble,
+				},
+				&OneOfMessageValue{
+					fieldName:     "ArrayValue",
+					protoID:       5,
+					returnMessage: arrayValueStruct,
+				},
+				&OneOfMessageValue{
+					fieldName:     "KvlistValue",
+					protoID:       6,
+					returnMessage: keyValueListStruct,
+				},
+				&OneOfPrimitiveValue{
+					fieldName:       "BytesValue",
+					protoID:         7,
+					originFieldName: "BytesValue",
+					protoType:       proto.TypeBytes,
+				},
+			},
+		},
+	},
+	hasOnlyOrig: true,
+}
+
 var keyValueListStruct = &messageStruct{
 	structName:     "KeyValueList",
 	description:    "KeyValueList is a list of KeyValue messages. We need KeyValueList as a message since oneof in AnyValue does not allow repeated fields.",
@@ -145,12 +209,6 @@ var timestampType = &TypedType{
 	testVal:     "1234567890",
 }
 
-var anyValue = &messageStruct{
-	structName:     "Value",
-	packageName:    "pcommon",
-	originFullName: "otlpcommon.AnyValue",
-}
-
 var traceIDType = &TypedType{
 	structName:  "TraceID",
 	packageName: "pcommon",

internal/cmd/pdatagen/internal/proto/field.go

@@ -53,7 +53,7 @@ func (pf *Field) DefaultValue() string {
 	case TypeBool:
 		return `false`
 	case TypeBytes:
-		return `[]byte{}`
+		return `nil`
 	case TypeString:
 		return `""`
 	case TypeMessage:

internal/cmd/pdatagen/internal/proto/json_marshal.go

@@ -80,12 +80,14 @@ const marshalJSONBytes = `{{ if .repeated -}}
 		}
 		dest.WriteArrayEnd()
 	}
-{{- else }}
+{{- else }}{{ if not .nullable }}
 	if len(orig.{{ .fieldName }}) > 0 {
+{{- end }}
 		dest.WriteObjectField("{{ .jsonTag }}")
 		dest.WriteBytes(orig.{{ .fieldName }})
+{{- if not .nullable -}}
 	}
-{{- end }}`
+{{- end }}{{- end }}`
 
 func (pf *Field) GenMarshalJSON() string {
 	tf := pf.getTemplateFields()

internal/cmd/pdatagen/internal/proto/json_unmarshal.go

@@ -68,6 +68,17 @@ const unmarshalJSONBytes = `	case {{ .allJSONTags }}:
 	for iter.ReadArray() {
 		orig.{{ .fieldName }} = append(orig.{{ .fieldName }}, iter.ReadBytes())
 	}
+{{ else if ne .oneOfGroup "" -}}
+	{
+		var ov *{{ .oneOfMessageFullName }}
+		if !UseProtoPooling.IsEnabled() {
+			ov = &{{ .oneOfMessageFullName }}{}
+		} else {
+			ov = ProtoPool{{ .oneOfMessageName }}.Get().(*{{ .oneOfMessageFullName }})
+		}
+		ov.{{ .fieldName }} = iter.ReadBytes()
+		orig.{{ .oneOfGroup }} = ov
+	}
 {{ else -}}
 	orig.{{ .fieldName }} = iter.ReadBytes()
 {{- end }}`

internal/cmd/pdatagen/internal/proto/proto_unmarshal.go

@@ -239,15 +239,23 @@ const unmarshalProtoBytes = `
 		} else {
 			ov = ProtoPool{{ .oneOfMessageName }}.Get().(*{{ .oneOfMessageFullName }})
 		}
-		ov.{{ .fieldName }} = make([]byte, length)
-		copy(ofv.{{ .fieldName }}, buf[startPos:pos])
+		if length != 0 {
+			ov.{{ .fieldName }} = make([]byte, length)
+			copy(ov.{{ .fieldName }}, buf[startPos:pos])
+		}
 		orig.{{ .oneOfGroup }} = ov
 {{- else if .repeated -}}
-		orig.{{ .fieldName }} = append(orig.{{ .fieldName }}, make([]byte, length))
-		copy(orig.{{ .fieldName }}[len(orig.{{ .fieldName }}) - 1], buf[startPos:pos])
+		if length != 0 {
+			orig.{{ .fieldName }} = append(orig.{{ .fieldName }}, make([]byte, length))
+			copy(orig.{{ .fieldName }}[len(orig.{{ .fieldName }}) - 1], buf[startPos:pos])
+		} else {
+			orig.{{ .fieldName }} = append(orig.{{ .fieldName }}, nil)
+		}
 {{- else -}}
-		orig.{{ .fieldName }} = make([]byte, length)
-		copy(orig.{{ .fieldName }}, buf[startPos:pos])
+		if length != 0 {
+			orig.{{ .fieldName }} = make([]byte, length)
+			copy(orig.{{ .fieldName }}, buf[startPos:pos])
+		}
 {{- end }}`
 
 const unmarshalProtoMessage = `