gtsocial-umbx

convert.go (15883B)

---

 // Copyright 2018 The Go Authors. All rights reserved.
 // Use of this source code is governed by a BSD-style
 // license that can be found in the LICENSE file.
 
 package impl
 
 import (
 	"fmt"
 	"reflect"
 
 	"google.golang.org/protobuf/reflect/protoreflect"
 )
 
 // unwrapper unwraps the value to the underlying value.
 // This is implemented by List and Map.
 type unwrapper interface {
 	protoUnwrap() interface{}
 }
 
 // A Converter coverts to/from Go reflect.Value types and protobuf protoreflect.Value types.
 type Converter interface {
 	// PBValueOf converts a reflect.Value to a protoreflect.Value.
 	PBValueOf(reflect.Value) protoreflect.Value
 
 	// GoValueOf converts a protoreflect.Value to a reflect.Value.
 	GoValueOf(protoreflect.Value) reflect.Value
 
 	// IsValidPB returns whether a protoreflect.Value is compatible with this type.
 	IsValidPB(protoreflect.Value) bool
 
 	// IsValidGo returns whether a reflect.Value is compatible with this type.
 	IsValidGo(reflect.Value) bool
 
 	// New returns a new field value.
 	// For scalars, it returns the default value of the field.
 	// For composite types, it returns a new mutable value.
 	New() protoreflect.Value
 
 	// Zero returns a new field value.
 	// For scalars, it returns the default value of the field.
 	// For composite types, it returns an immutable, empty value.
 	Zero() protoreflect.Value
 }
 
 // NewConverter matches a Go type with a protobuf field and returns a Converter
 // 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, fd protoreflect.FieldDescriptor) Converter {
 	switch {
 	case fd.IsList():
 		return newListConverter(t, fd)
 	case fd.IsMap():
 		return newMapConverter(t, fd)
 	default:
 		return newSingularConverter(t, fd)
 	}
 }
 
 var (
 	boolType    = reflect.TypeOf(bool(false))
 	int32Type   = reflect.TypeOf(int32(0))
 	int64Type   = reflect.TypeOf(int64(0))
 	uint32Type  = reflect.TypeOf(uint32(0))
 	uint64Type  = reflect.TypeOf(uint64(0))
 	float32Type = reflect.TypeOf(float32(0))
 	float64Type = reflect.TypeOf(float64(0))
 	stringType  = reflect.TypeOf(string(""))
 	bytesType   = reflect.TypeOf([]byte(nil))
 	byteType    = reflect.TypeOf(byte(0))
 )
 
 var (
 	boolZero    = protoreflect.ValueOfBool(false)
 	int32Zero   = protoreflect.ValueOfInt32(0)
 	int64Zero   = protoreflect.ValueOfInt64(0)
 	uint32Zero  = protoreflect.ValueOfUint32(0)
 	uint64Zero  = protoreflect.ValueOfUint64(0)
 	float32Zero = protoreflect.ValueOfFloat32(0)
 	float64Zero = protoreflect.ValueOfFloat64(0)
 	stringZero  = protoreflect.ValueOfString("")
 	bytesZero   = protoreflect.ValueOfBytes(nil)
 )
 
 func newSingularConverter(t reflect.Type, fd protoreflect.FieldDescriptor) Converter {
 	defVal := func(fd protoreflect.FieldDescriptor, zero protoreflect.Value) protoreflect.Value {
 		if fd.Cardinality() == protoreflect.Repeated {
 			// Default isn't defined for repeated fields.
 			return zero
 		}
 		return fd.Default()
 	}
 	switch fd.Kind() {
 	case protoreflect.BoolKind:
 		if t.Kind() == reflect.Bool {
 			return &boolConverter{t, defVal(fd, boolZero)}
 		}
 	case protoreflect.Int32Kind, protoreflect.Sint32Kind, protoreflect.Sfixed32Kind:
 		if t.Kind() == reflect.Int32 {
 			return &int32Converter{t, defVal(fd, int32Zero)}
 		}
 	case protoreflect.Int64Kind, protoreflect.Sint64Kind, protoreflect.Sfixed64Kind:
 		if t.Kind() == reflect.Int64 {
 			return &int64Converter{t, defVal(fd, int64Zero)}
 		}
 	case protoreflect.Uint32Kind, protoreflect.Fixed32Kind:
 		if t.Kind() == reflect.Uint32 {
 			return &uint32Converter{t, defVal(fd, uint32Zero)}
 		}
 	case protoreflect.Uint64Kind, protoreflect.Fixed64Kind:
 		if t.Kind() == reflect.Uint64 {
 			return &uint64Converter{t, defVal(fd, uint64Zero)}
 		}
 	case protoreflect.FloatKind:
 		if t.Kind() == reflect.Float32 {
 			return &float32Converter{t, defVal(fd, float32Zero)}
 		}
 	case protoreflect.DoubleKind:
 		if t.Kind() == reflect.Float64 {
 			return &float64Converter{t, defVal(fd, float64Zero)}
 		}
 	case protoreflect.StringKind:
 		if t.Kind() == reflect.String || (t.Kind() == reflect.Slice && t.Elem() == byteType) {
 			return &stringConverter{t, defVal(fd, stringZero)}
 		}
 	case protoreflect.BytesKind:
 		if t.Kind() == reflect.String || (t.Kind() == reflect.Slice && t.Elem() == byteType) {
 			return &bytesConverter{t, defVal(fd, bytesZero)}
 		}
 	case protoreflect.EnumKind:
 		// Handle enums, which must be a named int32 type.
 		if t.Kind() == reflect.Int32 {
 			return newEnumConverter(t, fd)
 		}
 	case protoreflect.MessageKind, protoreflect.GroupKind:
 		return newMessageConverter(t)
 	}
 	panic(fmt.Sprintf("invalid Go type %v for field %v", t, fd.FullName()))
 }
 
 type boolConverter struct {
 	goType reflect.Type
 	def    protoreflect.Value
 }
 
 func (c *boolConverter) PBValueOf(v reflect.Value) protoreflect.Value {
 	if v.Type() != c.goType {
 		panic(fmt.Sprintf("invalid type: got %v, want %v", v.Type(), c.goType))
 	}
 	return protoreflect.ValueOfBool(v.Bool())
 }
 func (c *boolConverter) GoValueOf(v protoreflect.Value) reflect.Value {
 	return reflect.ValueOf(v.Bool()).Convert(c.goType)
 }
 func (c *boolConverter) IsValidPB(v protoreflect.Value) bool {
 	_, ok := v.Interface().(bool)
 	return ok
 }
 func (c *boolConverter) IsValidGo(v reflect.Value) bool {
 	return v.IsValid() && v.Type() == c.goType
 }
 func (c *boolConverter) New() protoreflect.Value  { return c.def }
 func (c *boolConverter) Zero() protoreflect.Value { return c.def }
 
 type int32Converter struct {
 	goType reflect.Type
 	def    protoreflect.Value
 }
 
 func (c *int32Converter) PBValueOf(v reflect.Value) protoreflect.Value {
 	if v.Type() != c.goType {
 		panic(fmt.Sprintf("invalid type: got %v, want %v", v.Type(), c.goType))
 	}
 	return protoreflect.ValueOfInt32(int32(v.Int()))
 }
 func (c *int32Converter) GoValueOf(v protoreflect.Value) reflect.Value {
 	return reflect.ValueOf(int32(v.Int())).Convert(c.goType)
 }
 func (c *int32Converter) IsValidPB(v protoreflect.Value) bool {
 	_, ok := v.Interface().(int32)
 	return ok
 }
 func (c *int32Converter) IsValidGo(v reflect.Value) bool {
 	return v.IsValid() && v.Type() == c.goType
 }
 func (c *int32Converter) New() protoreflect.Value  { return c.def }
 func (c *int32Converter) Zero() protoreflect.Value { return c.def }
 
 type int64Converter struct {
 	goType reflect.Type
 	def    protoreflect.Value
 }
 
 func (c *int64Converter) PBValueOf(v reflect.Value) protoreflect.Value {
 	if v.Type() != c.goType {
 		panic(fmt.Sprintf("invalid type: got %v, want %v", v.Type(), c.goType))
 	}
 	return protoreflect.ValueOfInt64(int64(v.Int()))
 }
 func (c *int64Converter) GoValueOf(v protoreflect.Value) reflect.Value {
 	return reflect.ValueOf(int64(v.Int())).Convert(c.goType)
 }
 func (c *int64Converter) IsValidPB(v protoreflect.Value) bool {
 	_, ok := v.Interface().(int64)
 	return ok
 }
 func (c *int64Converter) IsValidGo(v reflect.Value) bool {
 	return v.IsValid() && v.Type() == c.goType
 }
 func (c *int64Converter) New() protoreflect.Value  { return c.def }
 func (c *int64Converter) Zero() protoreflect.Value { return c.def }
 
 type uint32Converter struct {
 	goType reflect.Type
 	def    protoreflect.Value
 }
 
 func (c *uint32Converter) PBValueOf(v reflect.Value) protoreflect.Value {
 	if v.Type() != c.goType {
 		panic(fmt.Sprintf("invalid type: got %v, want %v", v.Type(), c.goType))
 	}
 	return protoreflect.ValueOfUint32(uint32(v.Uint()))
 }
 func (c *uint32Converter) GoValueOf(v protoreflect.Value) reflect.Value {
 	return reflect.ValueOf(uint32(v.Uint())).Convert(c.goType)
 }
 func (c *uint32Converter) IsValidPB(v protoreflect.Value) bool {
 	_, ok := v.Interface().(uint32)
 	return ok
 }
 func (c *uint32Converter) IsValidGo(v reflect.Value) bool {
 	return v.IsValid() && v.Type() == c.goType
 }
 func (c *uint32Converter) New() protoreflect.Value  { return c.def }
 func (c *uint32Converter) Zero() protoreflect.Value { return c.def }
 
 type uint64Converter struct {
 	goType reflect.Type
 	def    protoreflect.Value
 }
 
 func (c *uint64Converter) PBValueOf(v reflect.Value) protoreflect.Value {
 	if v.Type() != c.goType {
 		panic(fmt.Sprintf("invalid type: got %v, want %v", v.Type(), c.goType))
 	}
 	return protoreflect.ValueOfUint64(uint64(v.Uint()))
 }
 func (c *uint64Converter) GoValueOf(v protoreflect.Value) reflect.Value {
 	return reflect.ValueOf(uint64(v.Uint())).Convert(c.goType)
 }
 func (c *uint64Converter) IsValidPB(v protoreflect.Value) bool {
 	_, ok := v.Interface().(uint64)
 	return ok
 }
 func (c *uint64Converter) IsValidGo(v reflect.Value) bool {
 	return v.IsValid() && v.Type() == c.goType
 }
 func (c *uint64Converter) New() protoreflect.Value  { return c.def }
 func (c *uint64Converter) Zero() protoreflect.Value { return c.def }
 
 type float32Converter struct {
 	goType reflect.Type
 	def    protoreflect.Value
 }
 
 func (c *float32Converter) PBValueOf(v reflect.Value) protoreflect.Value {
 	if v.Type() != c.goType {
 		panic(fmt.Sprintf("invalid type: got %v, want %v", v.Type(), c.goType))
 	}
 	return protoreflect.ValueOfFloat32(float32(v.Float()))
 }
 func (c *float32Converter) GoValueOf(v protoreflect.Value) reflect.Value {
 	return reflect.ValueOf(float32(v.Float())).Convert(c.goType)
 }
 func (c *float32Converter) IsValidPB(v protoreflect.Value) bool {
 	_, ok := v.Interface().(float32)
 	return ok
 }
 func (c *float32Converter) IsValidGo(v reflect.Value) bool {
 	return v.IsValid() && v.Type() == c.goType
 }
 func (c *float32Converter) New() protoreflect.Value  { return c.def }
 func (c *float32Converter) Zero() protoreflect.Value { return c.def }
 
 type float64Converter struct {
 	goType reflect.Type
 	def    protoreflect.Value
 }
 
 func (c *float64Converter) PBValueOf(v reflect.Value) protoreflect.Value {
 	if v.Type() != c.goType {
 		panic(fmt.Sprintf("invalid type: got %v, want %v", v.Type(), c.goType))
 	}
 	return protoreflect.ValueOfFloat64(float64(v.Float()))
 }
 func (c *float64Converter) GoValueOf(v protoreflect.Value) reflect.Value {
 	return reflect.ValueOf(float64(v.Float())).Convert(c.goType)
 }
 func (c *float64Converter) IsValidPB(v protoreflect.Value) bool {
 	_, ok := v.Interface().(float64)
 	return ok
 }
 func (c *float64Converter) IsValidGo(v reflect.Value) bool {
 	return v.IsValid() && v.Type() == c.goType
 }
 func (c *float64Converter) New() protoreflect.Value  { return c.def }
 func (c *float64Converter) Zero() protoreflect.Value { return c.def }
 
 type stringConverter struct {
 	goType reflect.Type
 	def    protoreflect.Value
 }
 
 func (c *stringConverter) PBValueOf(v reflect.Value) protoreflect.Value {
 	if v.Type() != c.goType {
 		panic(fmt.Sprintf("invalid type: got %v, want %v", v.Type(), c.goType))
 	}
 	return protoreflect.ValueOfString(v.Convert(stringType).String())
 }
 func (c *stringConverter) GoValueOf(v protoreflect.Value) reflect.Value {
 	// pref.Value.String never panics, so we go through an interface
 	// conversion here to check the type.
 	s := v.Interface().(string)
 	if c.goType.Kind() == reflect.Slice && s == "" {
 		return reflect.Zero(c.goType) // ensure empty string is []byte(nil)
 	}
 	return reflect.ValueOf(s).Convert(c.goType)
 }
 func (c *stringConverter) IsValidPB(v protoreflect.Value) bool {
 	_, ok := v.Interface().(string)
 	return ok
 }
 func (c *stringConverter) IsValidGo(v reflect.Value) bool {
 	return v.IsValid() && v.Type() == c.goType
 }
 func (c *stringConverter) New() protoreflect.Value  { return c.def }
 func (c *stringConverter) Zero() protoreflect.Value { return c.def }
 
 type bytesConverter struct {
 	goType reflect.Type
 	def    protoreflect.Value
 }
 
 func (c *bytesConverter) PBValueOf(v reflect.Value) protoreflect.Value {
 	if v.Type() != c.goType {
 		panic(fmt.Sprintf("invalid type: got %v, want %v", v.Type(), c.goType))
 	}
 	if c.goType.Kind() == reflect.String && v.Len() == 0 {
 		return protoreflect.ValueOfBytes(nil) // ensure empty string is []byte(nil)
 	}
 	return protoreflect.ValueOfBytes(v.Convert(bytesType).Bytes())
 }
 func (c *bytesConverter) GoValueOf(v protoreflect.Value) reflect.Value {
 	return reflect.ValueOf(v.Bytes()).Convert(c.goType)
 }
 func (c *bytesConverter) IsValidPB(v protoreflect.Value) bool {
 	_, ok := v.Interface().([]byte)
 	return ok
 }
 func (c *bytesConverter) IsValidGo(v reflect.Value) bool {
 	return v.IsValid() && v.Type() == c.goType
 }
 func (c *bytesConverter) New() protoreflect.Value  { return c.def }
 func (c *bytesConverter) Zero() protoreflect.Value { return c.def }
 
 type enumConverter struct {
 	goType reflect.Type
 	def    protoreflect.Value
 }
 
 func newEnumConverter(goType reflect.Type, fd protoreflect.FieldDescriptor) Converter {
 	var def protoreflect.Value
 	if fd.Cardinality() == protoreflect.Repeated {
 		def = protoreflect.ValueOfEnum(fd.Enum().Values().Get(0).Number())
 	} else {
 		def = fd.Default()
 	}
 	return &enumConverter{goType, def}
 }
 
 func (c *enumConverter) PBValueOf(v reflect.Value) protoreflect.Value {
 	if v.Type() != c.goType {
 		panic(fmt.Sprintf("invalid type: got %v, want %v", v.Type(), c.goType))
 	}
 	return protoreflect.ValueOfEnum(protoreflect.EnumNumber(v.Int()))
 }
 
 func (c *enumConverter) GoValueOf(v protoreflect.Value) reflect.Value {
 	return reflect.ValueOf(v.Enum()).Convert(c.goType)
 }
 
 func (c *enumConverter) IsValidPB(v protoreflect.Value) bool {
 	_, ok := v.Interface().(protoreflect.EnumNumber)
 	return ok
 }
 
 func (c *enumConverter) IsValidGo(v reflect.Value) bool {
 	return v.IsValid() && v.Type() == c.goType
 }
 
 func (c *enumConverter) New() protoreflect.Value {
 	return c.def
 }
 
 func (c *enumConverter) Zero() protoreflect.Value {
 	return c.def
 }
 
 type messageConverter struct {
 	goType reflect.Type
 }
 
 func newMessageConverter(goType reflect.Type) Converter {
 	return &messageConverter{goType}
 }
 
 func (c *messageConverter) PBValueOf(v reflect.Value) protoreflect.Value {
 	if v.Type() != c.goType {
 		panic(fmt.Sprintf("invalid type: got %v, want %v", v.Type(), c.goType))
 	}
 	if c.isNonPointer() {
 		if v.CanAddr() {
 			v = v.Addr() // T => *T
 		} else {
 			v = reflect.Zero(reflect.PtrTo(v.Type()))
 		}
 	}
 	if m, ok := v.Interface().(protoreflect.ProtoMessage); ok {
 		return protoreflect.ValueOfMessage(m.ProtoReflect())
 	}
 	return protoreflect.ValueOfMessage(legacyWrapMessage(v))
 }
 
 func (c *messageConverter) GoValueOf(v protoreflect.Value) reflect.Value {
 	m := v.Message()
 	var rv reflect.Value
 	if u, ok := m.(unwrapper); ok {
 		rv = reflect.ValueOf(u.protoUnwrap())
 	} else {
 		rv = reflect.ValueOf(m.Interface())
 	}
 	if c.isNonPointer() {
 		if rv.Type() != reflect.PtrTo(c.goType) {
 			panic(fmt.Sprintf("invalid type: got %v, want %v", rv.Type(), reflect.PtrTo(c.goType)))
 		}
 		if !rv.IsNil() {
 			rv = rv.Elem() // *T => T
 		} else {
 			rv = reflect.Zero(rv.Type().Elem())
 		}
 	}
 	if rv.Type() != c.goType {
 		panic(fmt.Sprintf("invalid type: got %v, want %v", rv.Type(), c.goType))
 	}
 	return rv
 }
 
 func (c *messageConverter) IsValidPB(v protoreflect.Value) bool {
 	m := v.Message()
 	var rv reflect.Value
 	if u, ok := m.(unwrapper); ok {
 		rv = reflect.ValueOf(u.protoUnwrap())
 	} else {
 		rv = reflect.ValueOf(m.Interface())
 	}
 	if c.isNonPointer() {
 		return rv.Type() == reflect.PtrTo(c.goType)
 	}
 	return rv.Type() == c.goType
 }
 
 func (c *messageConverter) IsValidGo(v reflect.Value) bool {
 	return v.IsValid() && v.Type() == c.goType
 }
 
 func (c *messageConverter) New() protoreflect.Value {
 	if c.isNonPointer() {
 		return c.PBValueOf(reflect.New(c.goType).Elem())
 	}
 	return c.PBValueOf(reflect.New(c.goType.Elem()))
 }
 
 func (c *messageConverter) Zero() protoreflect.Value {
 	return c.PBValueOf(reflect.Zero(c.goType))
 }
 
 // isNonPointer reports whether the type is a non-pointer type.
 // This never occurs for generated message types.
 func (c *messageConverter) isNonPointer() bool {
 	return c.goType.Kind() != reflect.Ptr
 }