| // 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" |
| pvalue "github.com/golang/protobuf/v2/internal/value" |
| 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) |
| newMessage func() pref.Message |
| } |
| |
| 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 { |
| ft := fs.Type |
| if ft.Kind() != reflect.Interface { |
| panic(fmt.Sprintf("invalid type: got %v, want interface kind", ft)) |
| } |
| if ot.Kind() != reflect.Struct { |
| panic(fmt.Sprintf("invalid type: got %v, want struct kind", ot)) |
| } |
| if !reflect.PtrTo(ot).Implements(ft) { |
| panic(fmt.Sprintf("invalid type: %v does not implement %v", ot, ft)) |
| } |
| conv := pvalue.NewLegacyConverter(ot.Field(0).Type, fd.Kind(), legacyWrapper) |
| fieldOffset := offsetOf(fs) |
| // TODO: Implement unsafe fast path? |
| return fieldInfo{ |
| // NOTE: The logic below intentionally assumes that oneof fields are |
| // well-formatted. That is, the oneof interface never contains a |
| // typed nil pointer to one of the wrapper structs. |
| |
| has: func(p pointer) bool { |
| if p.IsNil() { |
| return false |
| } |
| rv := p.Apply(fieldOffset).AsValueOf(fs.Type).Elem() |
| if rv.IsNil() || rv.Elem().Type().Elem() != ot { |
| return false |
| } |
| return true |
| }, |
| get: func(p pointer) pref.Value { |
| if p.IsNil() { |
| return defaultValueOf(fd) |
| } |
| rv := p.Apply(fieldOffset).AsValueOf(fs.Type).Elem() |
| if rv.IsNil() || rv.Elem().Type().Elem() != ot { |
| return defaultValueOf(fd) |
| } |
| rv = rv.Elem().Elem().Field(0) |
| return conv.PBValueOf(rv) |
| }, |
| set: func(p pointer, v pref.Value) { |
| rv := p.Apply(fieldOffset).AsValueOf(fs.Type).Elem() |
| if rv.IsNil() || rv.Elem().Type().Elem() != ot { |
| rv.Set(reflect.New(ot)) |
| } |
| rv = rv.Elem().Elem().Field(0) |
| rv.Set(conv.GoValueOf(v)) |
| }, |
| clear: func(p pointer) { |
| rv := p.Apply(fieldOffset).AsValueOf(fs.Type).Elem() |
| if rv.IsNil() || rv.Elem().Type().Elem() != ot { |
| return |
| } |
| rv.Set(reflect.Zero(rv.Type())) |
| }, |
| newMessage: func() pref.Message { |
| // This is only valid for messages and panics for other kinds. |
| return conv.MessageType.New() |
| }, |
| } |
| } |
| |
| func fieldInfoForMap(fd pref.FieldDescriptor, fs reflect.StructField) fieldInfo { |
| ft := fs.Type |
| if ft.Kind() != reflect.Map { |
| panic(fmt.Sprintf("invalid type: got %v, want map kind", ft)) |
| } |
| keyConv := pvalue.NewLegacyConverter(ft.Key(), fd.MessageType().Fields().ByNumber(1).Kind(), legacyWrapper) |
| valConv := pvalue.NewLegacyConverter(ft.Elem(), fd.MessageType().Fields().ByNumber(2).Kind(), legacyWrapper) |
| fieldOffset := offsetOf(fs) |
| // TODO: Implement unsafe fast path? |
| return fieldInfo{ |
| has: func(p pointer) bool { |
| if p.IsNil() { |
| return false |
| } |
| rv := p.Apply(fieldOffset).AsValueOf(fs.Type).Elem() |
| return rv.Len() > 0 |
| }, |
| get: func(p pointer) pref.Value { |
| if p.IsNil() { |
| v := reflect.Zero(reflect.PtrTo(fs.Type)).Interface() |
| return pref.ValueOf(pvalue.MapOf(v, keyConv, valConv)) |
| } |
| v := p.Apply(fieldOffset).AsIfaceOf(fs.Type) |
| return pref.ValueOf(pvalue.MapOf(v, keyConv, valConv)) |
| }, |
| set: func(p pointer, v pref.Value) { |
| rv := p.Apply(fieldOffset).AsValueOf(fs.Type).Elem() |
| rv.Set(reflect.ValueOf(v.Map().(pvalue.Unwrapper).ProtoUnwrap()).Elem()) |
| }, |
| clear: func(p pointer) { |
| rv := p.Apply(fieldOffset).AsValueOf(fs.Type).Elem() |
| rv.Set(reflect.Zero(rv.Type())) |
| }, |
| } |
| } |
| |
| func fieldInfoForList(fd pref.FieldDescriptor, fs reflect.StructField) fieldInfo { |
| ft := fs.Type |
| if ft.Kind() != reflect.Slice { |
| panic(fmt.Sprintf("invalid type: got %v, want slice kind", ft)) |
| } |
| conv := pvalue.NewLegacyConverter(ft.Elem(), fd.Kind(), legacyWrapper) |
| fieldOffset := offsetOf(fs) |
| // TODO: Implement unsafe fast path? |
| return fieldInfo{ |
| has: func(p pointer) bool { |
| if p.IsNil() { |
| return false |
| } |
| rv := p.Apply(fieldOffset).AsValueOf(fs.Type).Elem() |
| return rv.Len() > 0 |
| }, |
| get: func(p pointer) pref.Value { |
| if p.IsNil() { |
| v := reflect.Zero(reflect.PtrTo(fs.Type)).Interface() |
| return pref.ValueOf(pvalue.ListOf(v, conv)) |
| } |
| v := p.Apply(fieldOffset).AsIfaceOf(fs.Type) |
| return pref.ValueOf(pvalue.ListOf(v, conv)) |
| }, |
| set: func(p pointer, v pref.Value) { |
| rv := p.Apply(fieldOffset).AsValueOf(fs.Type).Elem() |
| rv.Set(reflect.ValueOf(v.List().(pvalue.Unwrapper).ProtoUnwrap()).Elem()) |
| }, |
| clear: func(p pointer) { |
| rv := p.Apply(fieldOffset).AsValueOf(fs.Type).Elem() |
| rv.Set(reflect.Zero(rv.Type())) |
| }, |
| } |
| } |
| |
| 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 := pvalue.NewLegacyConverter(ft, fd.Kind(), legacyWrapper) |
| fieldOffset := offsetOf(fs) |
| // TODO: Implement unsafe fast path? |
| return fieldInfo{ |
| has: func(p pointer) bool { |
| if p.IsNil() { |
| return false |
| } |
| rv := p.Apply(fieldOffset).AsValueOf(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 { |
| if p.IsNil() { |
| return defaultValueOf(fd) |
| } |
| rv := p.Apply(fieldOffset).AsValueOf(fs.Type).Elem() |
| if nullable { |
| if rv.IsNil() { |
| return defaultValueOf(fd) |
| } |
| if rv.Kind() == reflect.Ptr { |
| rv = rv.Elem() |
| } |
| } |
| return conv.PBValueOf(rv) |
| }, |
| set: func(p pointer, v pref.Value) { |
| rv := p.Apply(fieldOffset).AsValueOf(fs.Type).Elem() |
| if nullable && rv.Kind() == reflect.Ptr { |
| if rv.IsNil() { |
| rv.Set(reflect.New(ft)) |
| } |
| rv = rv.Elem() |
| } |
| rv.Set(conv.GoValueOf(v)) |
| if nullable && rv.Kind() == reflect.Slice && rv.IsNil() { |
| rv.Set(emptyBytes) |
| } |
| }, |
| clear: func(p pointer) { |
| rv := p.Apply(fieldOffset).AsValueOf(fs.Type).Elem() |
| rv.Set(reflect.Zero(rv.Type())) |
| }, |
| } |
| } |
| |
| func fieldInfoForMessage(fd pref.FieldDescriptor, fs reflect.StructField) fieldInfo { |
| ft := fs.Type |
| conv := pvalue.NewLegacyConverter(ft, fd.Kind(), legacyWrapper) |
| fieldOffset := offsetOf(fs) |
| // TODO: Implement unsafe fast path? |
| return fieldInfo{ |
| has: func(p pointer) bool { |
| if p.IsNil() { |
| return false |
| } |
| rv := p.Apply(fieldOffset).AsValueOf(fs.Type).Elem() |
| return !rv.IsNil() |
| }, |
| get: func(p pointer) pref.Value { |
| if p.IsNil() { |
| return pref.Value{} |
| } |
| rv := p.Apply(fieldOffset).AsValueOf(fs.Type).Elem() |
| if rv.IsNil() { |
| return pref.Value{} |
| } |
| return conv.PBValueOf(rv) |
| }, |
| set: func(p pointer, v pref.Value) { |
| rv := p.Apply(fieldOffset).AsValueOf(fs.Type).Elem() |
| rv.Set(conv.GoValueOf(v)) |
| if rv.IsNil() { |
| panic("invalid nil pointer") |
| } |
| }, |
| clear: func(p pointer) { |
| rv := p.Apply(fieldOffset).AsValueOf(fs.Type).Elem() |
| rv.Set(reflect.Zero(rv.Type())) |
| }, |
| newMessage: func() pref.Message { |
| return conv.MessageType.New() |
| }, |
| } |
| } |
| |
| // defaultValueOf returns the default value for the field. |
| func defaultValueOf(fd pref.FieldDescriptor) pref.Value { |
| if fd == nil { |
| return pref.Value{} |
| } |
| pv := fd.Default() // invalid Value for messages and repeated fields |
| if fd.Kind() == pref.BytesKind && pv.IsValid() && len(pv.Bytes()) > 0 { |
| return pref.ValueOf(append([]byte(nil), pv.Bytes()...)) // copy default bytes for safety |
| } |
| return pv |
| } |