reflect/prototype: initial commit
Add the prototype package which provides constructors for
protoreflect.{Enum,Message,Extension}Type.
Switch all usages of the internal/prototype equivalent to the new package.
Switch all custom implementions of {Enum,Message}Type to the new package.
Change-Id: Ia9dae6fed4f2b90e55c123627044a7faf098c4b1
Reviewed-on: https://go-review.googlesource.com/c/protobuf/+/178438
Reviewed-by: Damien Neil <dneil@google.com>
diff --git a/internal/value/convert.go b/internal/value/convert.go
index 35de822..eb8d570 100644
--- a/internal/value/convert.go
+++ b/internal/value/convert.go
@@ -11,7 +11,6 @@
"reflect"
pref "google.golang.org/protobuf/reflect/protoreflect"
- piface "google.golang.org/protobuf/runtime/protoiface"
)
// Unwrapper unwraps the value to the underlying value.
@@ -32,103 +31,60 @@
bytesType = reflect.TypeOf([]byte(nil))
enumIfaceV2 = reflect.TypeOf((*pref.Enum)(nil)).Elem()
- messageIfaceV1 = reflect.TypeOf((*piface.MessageV1)(nil)).Elem()
messageIfaceV2 = reflect.TypeOf((*pref.ProtoMessage)(nil)).Elem()
byteType = reflect.TypeOf(byte(0))
)
// NewConverter matches a Go type with a protobuf kind and returns a Converter
-// that converts between the two. NewConverter panics if it unable to provide a
-// conversion between the two. The Converter methods also panic when they are
-// called on incorrect Go types.
+// that converts between the two. Enums must be a named int32 kind that
+// implements protoreflect.Enum, and messages must be pointer to a named
+// struct type that implements protoreflect.ProtoMessage.
//
// This matcher deliberately supports a wider range of Go types than what
// protoc-gen-go historically generated to be able to automatically wrap some
// v1 messages generated by other forks of protoc-gen-go.
func NewConverter(t reflect.Type, k pref.Kind) Converter {
- return NewLegacyConverter(t, k, nil)
-}
-
-// LegacyWrapper is a set of wrapper methods that wraps legacy v1 Go types
-// to implement the v2 reflection APIs.
-type (
- LegacyWrapper interface {
- EnumOf(interface{}) LegacyEnum
- EnumTypeOf(interface{}) pref.EnumType
- EnumDescriptorOf(interface{}) pref.EnumDescriptor
-
- MessageOf(interface{}) LegacyMessage
- MessageTypeOf(interface{}) pref.MessageType
- MessageDescriptorOf(interface{}) pref.MessageDescriptor
-
- // TODO: Remove these eventually.
- // See the TODOs in internal/impl/legacy_extension.go.
- ExtensionDescFromType(pref.ExtensionType) *piface.ExtensionDescV1
- ExtensionTypeFromDesc(*piface.ExtensionDescV1) pref.ExtensionType
- }
-
- LegacyEnum = interface {
- pref.Enum
- ProtoUnwrap() interface{}
- }
-
- LegacyMessage = interface {
- pref.Message
- ProtoUnwrap() interface{}
- }
-)
-
-// NewLegacyConverter is identical to NewConverter,
-// but supports wrapping legacy v1 messages to implement the v2 message API
-// using the provided LegacyWrapper.
-func NewLegacyConverter(t reflect.Type, k pref.Kind, w LegacyWrapper) Converter {
switch k {
case pref.BoolKind:
if t.Kind() == reflect.Bool {
- return makeScalarConverter(t, boolType)
+ return newScalarConverter(t, boolType)
}
case pref.Int32Kind, pref.Sint32Kind, pref.Sfixed32Kind:
if t.Kind() == reflect.Int32 {
- return makeScalarConverter(t, int32Type)
+ return newScalarConverter(t, int32Type)
}
case pref.Int64Kind, pref.Sint64Kind, pref.Sfixed64Kind:
if t.Kind() == reflect.Int64 {
- return makeScalarConverter(t, int64Type)
+ return newScalarConverter(t, int64Type)
}
case pref.Uint32Kind, pref.Fixed32Kind:
if t.Kind() == reflect.Uint32 {
- return makeScalarConverter(t, uint32Type)
+ return newScalarConverter(t, uint32Type)
}
case pref.Uint64Kind, pref.Fixed64Kind:
if t.Kind() == reflect.Uint64 {
- return makeScalarConverter(t, uint64Type)
+ return newScalarConverter(t, uint64Type)
}
case pref.FloatKind:
if t.Kind() == reflect.Float32 {
- return makeScalarConverter(t, float32Type)
+ return newScalarConverter(t, float32Type)
}
case pref.DoubleKind:
if t.Kind() == reflect.Float64 {
- return makeScalarConverter(t, float64Type)
+ return newScalarConverter(t, float64Type)
}
case pref.StringKind:
if t.Kind() == reflect.String || (t.Kind() == reflect.Slice && t.Elem() == byteType) {
- return makeScalarConverter(t, stringType)
+ return newScalarConverter(t, stringType)
}
case pref.BytesKind:
if t.Kind() == reflect.String || (t.Kind() == reflect.Slice && t.Elem() == byteType) {
- return makeScalarConverter(t, bytesType)
+ return newScalarConverter(t, bytesType)
}
case pref.EnumKind:
// Handle enums, which must be a named int32 type.
- if t.PkgPath() != "" && t.Kind() == reflect.Int32 {
- var et pref.EnumType
- if t.Implements(enumIfaceV2) {
- et = &enumType{reflect.Zero(t).Interface().(pref.Enum).Descriptor(), t}
- } else {
- et = w.EnumTypeOf(reflect.Zero(t).Interface())
- }
+ if t.Implements(enumIfaceV2) && t.Kind() == reflect.Int32 {
return Converter{
PBValueOf: func(v reflect.Value) pref.Value {
if v.Type() != t {
@@ -139,44 +95,38 @@
GoValueOf: func(v pref.Value) reflect.Value {
return reflect.ValueOf(v.Enum()).Convert(t)
},
- EnumType: et,
- IsLegacy: !t.Implements(enumIfaceV2),
+ NewEnum: func(n pref.EnumNumber) pref.Enum {
+ return reflect.ValueOf(n).Convert(t).Interface().(pref.Enum)
+ },
}
}
case pref.MessageKind, pref.GroupKind:
// Handle v2 messages, which must satisfy the proto.Message interface.
- if t.Kind() == reflect.Ptr && t.Implements(messageIfaceV2) {
- md := reflect.Zero(t).Interface().(pref.ProtoMessage).ProtoReflect().Descriptor()
- mt := &messageType{md, t}
- return NewMessageConverter(mt)
- }
-
- // Handle v1 messages, which we need to wrap as a v2 message.
- if w != nil && t.Kind() == reflect.Ptr && t.Implements(messageIfaceV1) {
- mt := w.MessageTypeOf(reflect.Zero(t).Interface())
+ if t.Implements(messageIfaceV2) && t.Kind() == reflect.Ptr && t.Elem().Kind() == reflect.Struct {
return Converter{
PBValueOf: func(v reflect.Value) pref.Value {
if v.Type() != t {
panic(fmt.Sprintf("invalid type: got %v, want %v", v.Type(), t))
}
- return pref.ValueOf(w.MessageOf(v.Interface()))
+ return pref.ValueOf(v.Interface().(pref.ProtoMessage).ProtoReflect())
},
GoValueOf: func(v pref.Value) reflect.Value {
- rv := reflect.ValueOf(v.Message().(Unwrapper).ProtoUnwrap())
+ rv := reflect.ValueOf(v.Message().Interface())
if rv.Type() != t {
panic(fmt.Sprintf("invalid type: got %v, want %v", rv.Type(), t))
}
return rv
},
- MessageType: mt,
- IsLegacy: true,
+ NewMessage: func() pref.Message {
+ return reflect.New(t.Elem()).Interface().(pref.ProtoMessage).ProtoReflect()
+ },
}
}
}
panic(fmt.Sprintf("invalid Go type %v for protobuf kind %v", t, k))
}
-func makeScalarConverter(goType, pbType reflect.Type) Converter {
+func newScalarConverter(goType, pbType reflect.Type) Converter {
return Converter{
PBValueOf: func(v reflect.Value) pref.Value {
if v.Type() != goType {
@@ -200,83 +150,11 @@
}
}
-// NewEnumConverter returns a converter for an EnumType, whose GoType must implement protoreflect.Enum.
-func NewEnumConverter(et pref.EnumType) Converter {
- t := et.GoType()
- if !t.Implements(enumIfaceV2) {
- panic(fmt.Sprintf("invalid type: %v does not implement %v", t, enumIfaceV2))
- }
- return Converter{
- PBValueOf: func(v reflect.Value) pref.Value {
- if v.Type() != t {
- panic(fmt.Sprintf("invalid type: got %v, want %v", v.Type(), t))
- }
- e := v.Interface().(pref.Enum)
- return pref.ValueOf(e.Number())
- },
- GoValueOf: func(v pref.Value) reflect.Value {
- return reflect.ValueOf(et.New(v.Enum()))
- },
- EnumType: et,
- }
-}
-
-// NewMessageConverter returns a converter for a MessageType, whose GoType must implement protoreflect.ProtoMessage.
-func NewMessageConverter(mt pref.MessageType) Converter {
- t := mt.GoType()
- if !t.Implements(messageIfaceV2) {
- panic(fmt.Sprintf("invalid type: %v does not implement %v", t, messageIfaceV2))
- }
- return Converter{
- PBValueOf: func(v reflect.Value) pref.Value {
- if v.Type() != t {
- panic(fmt.Sprintf("invalid type: got %v, want %v", v.Type(), t))
- }
- return pref.ValueOf(v.Interface().(pref.ProtoMessage).ProtoReflect())
- },
- GoValueOf: func(v pref.Value) reflect.Value {
- rv := reflect.ValueOf(v.Message().Interface())
- if rv.Type() != t {
- panic(fmt.Sprintf("invalid type: got %v, want %v", rv.Type(), t))
- }
- return rv
- },
- MessageType: mt,
- }
-}
-
// Converter provides functions for converting to/from Go reflect.Value types
// and protobuf protoreflect.Value types.
type Converter struct {
- PBValueOf func(reflect.Value) pref.Value
- GoValueOf func(pref.Value) reflect.Value
- EnumType pref.EnumType
- MessageType pref.MessageType
- IsLegacy bool
-}
-
-// TODO: This needs to be centralized in a package.
-type enumType struct {
- // TODO: Remove me as an embedded field.
- pref.EnumDescriptor
- typ reflect.Type // must implement protoreflect.Enum
-}
-
-func (t *enumType) Descriptor() pref.EnumDescriptor { return t.EnumDescriptor }
-func (t *enumType) GoType() reflect.Type { return t.typ }
-func (t *enumType) New(n pref.EnumNumber) pref.Enum {
- return reflect.ValueOf(n).Convert(t.typ).Interface().(pref.Enum)
-}
-
-// TODO: This needs to be centralized in a package.
-type messageType struct {
- // TODO: Remove me as an embedded field.
- pref.MessageDescriptor
- typ reflect.Type // must implement protoreflect.ProtoMessage
-}
-
-func (t *messageType) Descriptor() pref.MessageDescriptor { return t.MessageDescriptor }
-func (t *messageType) GoType() reflect.Type { return t.typ }
-func (t *messageType) New() pref.Message {
- return reflect.New(t.typ.Elem()).Interface().(pref.ProtoMessage).ProtoReflect()
+ PBValueOf func(reflect.Value) pref.Value
+ GoValueOf func(pref.Value) reflect.Value
+ NewEnum func(pref.EnumNumber) pref.Enum
+ NewMessage func() pref.Message
}
diff --git a/internal/value/list.go b/internal/value/list.go
index f40a73f..5181f4f 100644
--- a/internal/value/list.go
+++ b/internal/value/list.go
@@ -43,7 +43,7 @@
ls.v.Elem().Set(ls.v.Elem().Slice(0, i))
}
func (ls listReflect) NewMessage() pref.Message {
- return ls.conv.MessageType.New()
+ return ls.conv.NewMessage()
}
func (ls listReflect) ProtoUnwrap() interface{} {
return ls.v.Interface()
diff --git a/internal/value/map.go b/internal/value/map.go
index 3461d2e..9fc7358 100644
--- a/internal/value/map.go
+++ b/internal/value/map.go
@@ -77,7 +77,7 @@
}
}
func (ms mapReflect) NewMessage() pref.Message {
- return ms.valConv.MessageType.New()
+ return ms.valConv.NewMessage()
}
func (ms mapReflect) ProtoUnwrap() interface{} {
return ms.v.Interface()