| // 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" |
| |
| "github.com/golang/protobuf/v2/internal/flags" |
| pref "github.com/golang/protobuf/v2/reflect/protoreflect" |
| ) |
| |
| type fieldInfo struct { |
| // TODO: specialize marshal and unmarshal functions? |
| |
| has func(pointer) bool |
| get func(pointer) pref.Value |
| set func(pointer, pref.Value) |
| clear func(pointer) |
| mutable func(pointer) pref.Mutable |
| } |
| |
| func fieldInfoForWeak(fd pref.FieldDescriptor, fs reflect.StructField) fieldInfo { |
| if !flags.Proto1Legacy { |
| panic("weak fields not supported") |
| } |
| // TODO: support weak fields. |
| panic(fmt.Sprintf("invalid field: %v", fd)) |
| } |
| |
| func fieldInfoForOneof(fd pref.FieldDescriptor, fs reflect.StructField, ot reflect.Type) fieldInfo { |
| // TODO: support oneof fields. |
| panic(fmt.Sprintf("invalid field: %v", fd)) |
| } |
| |
| func fieldInfoForMap(fd pref.FieldDescriptor, fs reflect.StructField) fieldInfo { |
| // TODO: support map fields. |
| panic(fmt.Sprintf("invalid field: %v", fd)) |
| } |
| |
| func fieldInfoForVector(fd pref.FieldDescriptor, fs reflect.StructField) fieldInfo { |
| // TODO: support vector fields. |
| panic(fmt.Sprintf("invalid field: %v", fd)) |
| } |
| |
| var emptyBytes = reflect.ValueOf([]byte{}) |
| |
| func fieldInfoForScalar(fd pref.FieldDescriptor, fs reflect.StructField) fieldInfo { |
| ft := fs.Type |
| nullable := fd.Syntax() == pref.Proto2 |
| if nullable { |
| if ft.Kind() != reflect.Ptr && ft.Kind() != reflect.Slice { |
| panic(fmt.Sprintf("invalid type: got %v, want pointer", ft)) |
| } |
| if ft.Kind() == reflect.Ptr { |
| ft = ft.Elem() |
| } |
| } |
| conv := matchGoTypePBKind(ft, fd.Kind()) |
| fieldOffset := offsetOf(fs) |
| // TODO: Implement unsafe fast path? |
| return fieldInfo{ |
| has: func(p pointer) bool { |
| rv := p.apply(fieldOffset).asType(fs.Type).Elem() |
| if nullable { |
| return !rv.IsNil() |
| } |
| switch rv.Kind() { |
| case reflect.Bool: |
| return rv.Bool() |
| case reflect.Int32, reflect.Int64: |
| return rv.Int() > 0 |
| case reflect.Uint32, reflect.Uint64: |
| return rv.Uint() > 0 |
| case reflect.Float32, reflect.Float64: |
| return rv.Float() > 0 |
| case reflect.String, reflect.Slice: |
| return rv.Len() > 0 |
| default: |
| panic(fmt.Sprintf("invalid type: %v", rv.Type())) // should never happen |
| } |
| }, |
| get: func(p pointer) pref.Value { |
| rv := p.apply(fieldOffset).asType(fs.Type).Elem() |
| if nullable { |
| if rv.IsNil() { |
| pv := fd.Default() |
| if fd.Kind() == pref.BytesKind && len(pv.Bytes()) > 0 { |
| return pref.ValueOf(append([]byte(nil), pv.Bytes()...)) // copy default bytes for safety |
| } |
| return pv |
| } |
| if rv.Kind() == reflect.Ptr { |
| rv = rv.Elem() |
| } |
| } |
| return conv.toPB(rv) |
| }, |
| set: func(p pointer, v pref.Value) { |
| rv := p.apply(fieldOffset).asType(fs.Type).Elem() |
| if nullable && rv.Kind() == reflect.Ptr { |
| if rv.IsNil() { |
| rv.Set(reflect.New(ft)) |
| } |
| rv = rv.Elem() |
| } |
| rv.Set(conv.toGo(v)) |
| if nullable && rv.Kind() == reflect.Slice && rv.IsNil() { |
| rv.Set(emptyBytes) |
| } |
| }, |
| clear: func(p pointer) { |
| rv := p.apply(fieldOffset).asType(fs.Type).Elem() |
| rv.Set(reflect.Zero(rv.Type())) |
| }, |
| mutable: func(p pointer) pref.Mutable { |
| panic("invalid mutable call") |
| }, |
| } |
| } |
| |
| func fieldInfoForMessage(fd pref.FieldDescriptor, fs reflect.StructField) fieldInfo { |
| // TODO: support vector fields. |
| panic(fmt.Sprintf("invalid field: %v", fd)) |
| } |
| |
| // messageV1 is the protoV1.Message interface. |
| type messageV1 interface { |
| Reset() |
| String() string |
| ProtoMessage() |
| } |
| |
| 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)) |
| |
| enumIfaceV2 = reflect.TypeOf((*pref.ProtoEnum)(nil)).Elem() |
| messageIfaceV1 = reflect.TypeOf((*messageV1)(nil)).Elem() |
| messageIfaceV2 = reflect.TypeOf((*pref.ProtoMessage)(nil)).Elem() |
| |
| byteType = reflect.TypeOf(byte(0)) |
| ) |
| |
| // matchGoTypePBKind matches a Go type with the protobuf kind. |
| // |
| // 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 matchGoTypePBKind(t reflect.Type, k pref.Kind) converter { |
| switch k { |
| case pref.BoolKind: |
| if t.Kind() == reflect.Bool { |
| return makeScalarConverter(t, boolType) |
| } |
| case pref.Int32Kind, pref.Sint32Kind, pref.Sfixed32Kind: |
| if t.Kind() == reflect.Int32 { |
| return makeScalarConverter(t, int32Type) |
| } |
| case pref.Int64Kind, pref.Sint64Kind, pref.Sfixed64Kind: |
| if t.Kind() == reflect.Int64 { |
| return makeScalarConverter(t, int64Type) |
| } |
| case pref.Uint32Kind, pref.Fixed32Kind: |
| if t.Kind() == reflect.Uint32 { |
| return makeScalarConverter(t, uint32Type) |
| } |
| case pref.Uint64Kind, pref.Fixed64Kind: |
| if t.Kind() == reflect.Uint64 { |
| return makeScalarConverter(t, uint64Type) |
| } |
| case pref.FloatKind: |
| if t.Kind() == reflect.Float32 { |
| return makeScalarConverter(t, float32Type) |
| } |
| case pref.DoubleKind: |
| if t.Kind() == reflect.Float64 { |
| return makeScalarConverter(t, float64Type) |
| } |
| case pref.StringKind: |
| if t.Kind() == reflect.String || (t.Kind() == reflect.Slice && t.Elem() == byteType) { |
| return makeScalarConverter(t, stringType) |
| } |
| case pref.BytesKind: |
| if t.Kind() == reflect.String || (t.Kind() == reflect.Slice && t.Elem() == byteType) { |
| return makeScalarConverter(t, bytesType) |
| } |
| case pref.EnumKind: |
| // Handle v2 enums, which must satisfy the proto.Enum interface. |
| if t.Kind() != reflect.Ptr && t.Implements(enumIfaceV2) { |
| // TODO: implement this. |
| } |
| |
| // Handle v1 enums, which we identify as simply a named int32 type. |
| if t.Kind() == reflect.Int32 && t.PkgPath() != "" { |
| // TODO: need logic to wrap a legacy enum to implement this. |
| } |
| case pref.MessageKind, pref.GroupKind: |
| // Handle v2 messages, which must satisfy the proto.Message interface. |
| if t.Kind() == reflect.Ptr && t.Implements(messageIfaceV2) { |
| // TODO: implement this. |
| } |
| |
| // Handle v1 messages, which we need to wrap as a v2 message. |
| if t.Kind() == reflect.Ptr && t.Implements(messageIfaceV1) { |
| // TODO: need logic to wrap a legacy message. |
| } |
| } |
| panic(fmt.Sprintf("invalid Go type %v for protobuf kind %v", t, k)) |
| } |
| |
| // converter provides functions for converting to/from Go reflect.Value types |
| // and protobuf protoreflect.Value types. |
| type converter struct { |
| toPB func(reflect.Value) pref.Value |
| toGo func(pref.Value) reflect.Value |
| } |
| |
| func makeScalarConverter(goType, pbType reflect.Type) converter { |
| return converter{ |
| toPB: func(v reflect.Value) pref.Value { |
| if v.Type() != goType { |
| panic(fmt.Sprintf("invalid type: got %v, want %v", v.Type(), goType)) |
| } |
| if goType.Kind() == reflect.String && pbType.Kind() == reflect.Slice && v.Len() == 0 { |
| return pref.ValueOf([]byte(nil)) // ensure empty string is []byte(nil) |
| } |
| return pref.ValueOf(v.Convert(pbType).Interface()) |
| }, |
| toGo: func(v pref.Value) reflect.Value { |
| rv := reflect.ValueOf(v.Interface()) |
| if rv.Type() != pbType { |
| panic(fmt.Sprintf("invalid type: got %v, want %v", rv.Type(), pbType)) |
| } |
| if pbType.Kind() == reflect.String && goType.Kind() == reflect.Slice && rv.Len() == 0 { |
| return reflect.Zero(goType) // ensure empty string is []byte(nil) |
| } |
| return rv.Convert(goType) |
| }, |
| } |
| } |