Current File : /opt/go/pkg/mod/google.golang.org/protobuf@v1.30.0/internal/impl//convert.go
// 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
}
