| // 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" |
| "math" |
| "reflect" |
| "sync" |
| |
| "google.golang.org/protobuf/internal/flags" |
| "google.golang.org/protobuf/reflect/protoreflect" |
| "google.golang.org/protobuf/reflect/protoregistry" |
| ) |
| |
| type fieldInfo struct { |
| fieldDesc protoreflect.FieldDescriptor |
| |
| // These fields are used for protobuf reflection support. |
| has func(pointer) bool |
| clear func(pointer) |
| get func(pointer) protoreflect.Value |
| set func(pointer, protoreflect.Value) |
| mutable func(pointer) protoreflect.Value |
| newMessage func() protoreflect.Message |
| newField func() protoreflect.Value |
| } |
| |
| func fieldInfoForMissing(fd protoreflect.FieldDescriptor) fieldInfo { |
| // This never occurs for generated message types. |
| // It implies that a hand-crafted type has missing Go fields |
| // for specific protobuf message fields. |
| return fieldInfo{ |
| fieldDesc: fd, |
| has: func(p pointer) bool { |
| return false |
| }, |
| clear: func(p pointer) { |
| panic("missing Go struct field for " + string(fd.FullName())) |
| }, |
| get: func(p pointer) protoreflect.Value { |
| return fd.Default() |
| }, |
| set: func(p pointer, v protoreflect.Value) { |
| panic("missing Go struct field for " + string(fd.FullName())) |
| }, |
| mutable: func(p pointer) protoreflect.Value { |
| panic("missing Go struct field for " + string(fd.FullName())) |
| }, |
| newMessage: func() protoreflect.Message { |
| panic("missing Go struct field for " + string(fd.FullName())) |
| }, |
| newField: func() protoreflect.Value { |
| if v := fd.Default(); v.IsValid() { |
| return v |
| } |
| panic("missing Go struct field for " + string(fd.FullName())) |
| }, |
| } |
| } |
| |
| func fieldInfoForOneof(fd protoreflect.FieldDescriptor, fs reflect.StructField, x exporter, ot reflect.Type) fieldInfo { |
| ft := fs.Type |
| if ft.Kind() != reflect.Interface { |
| panic(fmt.Sprintf("field %v has invalid type: got %v, want interface kind", fd.FullName(), ft)) |
| } |
| if ot.Kind() != reflect.Struct { |
| panic(fmt.Sprintf("field %v has invalid type: got %v, want struct kind", fd.FullName(), ot)) |
| } |
| if !reflect.PtrTo(ot).Implements(ft) { |
| panic(fmt.Sprintf("field %v has invalid type: %v does not implement %v", fd.FullName(), ot, ft)) |
| } |
| conv := NewConverter(ot.Field(0).Type, fd) |
| isMessage := fd.Message() != nil |
| |
| // TODO: Implement unsafe fast path? |
| fieldOffset := offsetOf(fs, x) |
| 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. |
| |
| fieldDesc: fd, |
| 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 || rv.Elem().IsNil() { |
| return false |
| } |
| return true |
| }, |
| clear: func(p pointer) { |
| rv := p.Apply(fieldOffset).AsValueOf(fs.Type).Elem() |
| if rv.IsNil() || rv.Elem().Type().Elem() != ot { |
| // NOTE: We intentionally don't check for rv.Elem().IsNil() |
| // so that (*OneofWrapperType)(nil) gets cleared to nil. |
| return |
| } |
| rv.Set(reflect.Zero(rv.Type())) |
| }, |
| get: func(p pointer) protoreflect.Value { |
| if p.IsNil() { |
| return conv.Zero() |
| } |
| rv := p.Apply(fieldOffset).AsValueOf(fs.Type).Elem() |
| if rv.IsNil() || rv.Elem().Type().Elem() != ot || rv.Elem().IsNil() { |
| return conv.Zero() |
| } |
| rv = rv.Elem().Elem().Field(0) |
| return conv.PBValueOf(rv) |
| }, |
| set: func(p pointer, v protoreflect.Value) { |
| rv := p.Apply(fieldOffset).AsValueOf(fs.Type).Elem() |
| if rv.IsNil() || rv.Elem().Type().Elem() != ot || rv.Elem().IsNil() { |
| rv.Set(reflect.New(ot)) |
| } |
| rv = rv.Elem().Elem().Field(0) |
| rv.Set(conv.GoValueOf(v)) |
| }, |
| mutable: func(p pointer) protoreflect.Value { |
| if !isMessage { |
| panic(fmt.Sprintf("field %v with invalid Mutable call on field with non-composite type", fd.FullName())) |
| } |
| rv := p.Apply(fieldOffset).AsValueOf(fs.Type).Elem() |
| if rv.IsNil() || rv.Elem().Type().Elem() != ot || rv.Elem().IsNil() { |
| rv.Set(reflect.New(ot)) |
| } |
| rv = rv.Elem().Elem().Field(0) |
| if rv.Kind() == reflect.Ptr && rv.IsNil() { |
| rv.Set(conv.GoValueOf(protoreflect.ValueOfMessage(conv.New().Message()))) |
| } |
| return conv.PBValueOf(rv) |
| }, |
| newMessage: func() protoreflect.Message { |
| return conv.New().Message() |
| }, |
| newField: func() protoreflect.Value { |
| return conv.New() |
| }, |
| } |
| } |
| |
| func fieldInfoForMap(fd protoreflect.FieldDescriptor, fs reflect.StructField, x exporter) fieldInfo { |
| ft := fs.Type |
| if ft.Kind() != reflect.Map { |
| panic(fmt.Sprintf("field %v has invalid type: got %v, want map kind", fd.FullName(), ft)) |
| } |
| conv := NewConverter(ft, fd) |
| |
| // TODO: Implement unsafe fast path? |
| fieldOffset := offsetOf(fs, x) |
| return fieldInfo{ |
| fieldDesc: fd, |
| has: func(p pointer) bool { |
| if p.IsNil() { |
| return false |
| } |
| rv := p.Apply(fieldOffset).AsValueOf(fs.Type).Elem() |
| return rv.Len() > 0 |
| }, |
| clear: func(p pointer) { |
| rv := p.Apply(fieldOffset).AsValueOf(fs.Type).Elem() |
| rv.Set(reflect.Zero(rv.Type())) |
| }, |
| get: func(p pointer) protoreflect.Value { |
| if p.IsNil() { |
| return conv.Zero() |
| } |
| rv := p.Apply(fieldOffset).AsValueOf(fs.Type).Elem() |
| if rv.Len() == 0 { |
| return conv.Zero() |
| } |
| return conv.PBValueOf(rv) |
| }, |
| set: func(p pointer, v protoreflect.Value) { |
| rv := p.Apply(fieldOffset).AsValueOf(fs.Type).Elem() |
| pv := conv.GoValueOf(v) |
| if pv.IsNil() { |
| panic(fmt.Sprintf("map field %v cannot be set with read-only value", fd.FullName())) |
| } |
| rv.Set(pv) |
| }, |
| mutable: func(p pointer) protoreflect.Value { |
| v := p.Apply(fieldOffset).AsValueOf(fs.Type).Elem() |
| if v.IsNil() { |
| v.Set(reflect.MakeMap(fs.Type)) |
| } |
| return conv.PBValueOf(v) |
| }, |
| newField: func() protoreflect.Value { |
| return conv.New() |
| }, |
| } |
| } |
| |
| func fieldInfoForList(fd protoreflect.FieldDescriptor, fs reflect.StructField, x exporter) fieldInfo { |
| ft := fs.Type |
| if ft.Kind() != reflect.Slice { |
| panic(fmt.Sprintf("field %v has invalid type: got %v, want slice kind", fd.FullName(), ft)) |
| } |
| conv := NewConverter(reflect.PtrTo(ft), fd) |
| |
| // TODO: Implement unsafe fast path? |
| fieldOffset := offsetOf(fs, x) |
| return fieldInfo{ |
| fieldDesc: fd, |
| has: func(p pointer) bool { |
| if p.IsNil() { |
| return false |
| } |
| rv := p.Apply(fieldOffset).AsValueOf(fs.Type).Elem() |
| return rv.Len() > 0 |
| }, |
| clear: func(p pointer) { |
| rv := p.Apply(fieldOffset).AsValueOf(fs.Type).Elem() |
| rv.Set(reflect.Zero(rv.Type())) |
| }, |
| get: func(p pointer) protoreflect.Value { |
| if p.IsNil() { |
| return conv.Zero() |
| } |
| rv := p.Apply(fieldOffset).AsValueOf(fs.Type) |
| if rv.Elem().Len() == 0 { |
| return conv.Zero() |
| } |
| return conv.PBValueOf(rv) |
| }, |
| set: func(p pointer, v protoreflect.Value) { |
| rv := p.Apply(fieldOffset).AsValueOf(fs.Type).Elem() |
| pv := conv.GoValueOf(v) |
| if pv.IsNil() { |
| panic(fmt.Sprintf("list field %v cannot be set with read-only value", fd.FullName())) |
| } |
| rv.Set(pv.Elem()) |
| }, |
| mutable: func(p pointer) protoreflect.Value { |
| v := p.Apply(fieldOffset).AsValueOf(fs.Type) |
| return conv.PBValueOf(v) |
| }, |
| newField: func() protoreflect.Value { |
| return conv.New() |
| }, |
| } |
| } |
| |
| var ( |
| nilBytes = reflect.ValueOf([]byte(nil)) |
| emptyBytes = reflect.ValueOf([]byte{}) |
| ) |
| |
| func fieldInfoForScalar(fd protoreflect.FieldDescriptor, fs reflect.StructField, x exporter) fieldInfo { |
| ft := fs.Type |
| nullable := fd.HasPresence() |
| isBytes := ft.Kind() == reflect.Slice && ft.Elem().Kind() == reflect.Uint8 |
| if nullable { |
| if ft.Kind() != reflect.Ptr && ft.Kind() != reflect.Slice { |
| // This never occurs for generated message types. |
| // Despite the protobuf type system specifying presence, |
| // the Go field type cannot represent it. |
| nullable = false |
| } |
| if ft.Kind() == reflect.Ptr { |
| ft = ft.Elem() |
| } |
| } |
| conv := NewConverter(ft, fd) |
| |
| // TODO: Implement unsafe fast path? |
| fieldOffset := offsetOf(fs, x) |
| return fieldInfo{ |
| fieldDesc: fd, |
| 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 || math.Signbit(rv.Float()) |
| case reflect.String, reflect.Slice: |
| return rv.Len() > 0 |
| default: |
| panic(fmt.Sprintf("field %v has invalid type: %v", fd.FullName(), rv.Type())) // should never happen |
| } |
| }, |
| clear: func(p pointer) { |
| rv := p.Apply(fieldOffset).AsValueOf(fs.Type).Elem() |
| rv.Set(reflect.Zero(rv.Type())) |
| }, |
| get: func(p pointer) protoreflect.Value { |
| if p.IsNil() { |
| return conv.Zero() |
| } |
| rv := p.Apply(fieldOffset).AsValueOf(fs.Type).Elem() |
| if nullable { |
| if rv.IsNil() { |
| return conv.Zero() |
| } |
| if rv.Kind() == reflect.Ptr { |
| rv = rv.Elem() |
| } |
| } |
| return conv.PBValueOf(rv) |
| }, |
| set: func(p pointer, v protoreflect.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 isBytes && rv.Len() == 0 { |
| if nullable { |
| rv.Set(emptyBytes) // preserve presence |
| } else { |
| rv.Set(nilBytes) // do not preserve presence |
| } |
| } |
| }, |
| newField: func() protoreflect.Value { |
| return conv.New() |
| }, |
| } |
| } |
| |
| func fieldInfoForWeakMessage(fd protoreflect.FieldDescriptor, weakOffset offset) fieldInfo { |
| if !flags.ProtoLegacy { |
| panic("no support for proto1 weak fields") |
| } |
| |
| var once sync.Once |
| var messageType protoreflect.MessageType |
| lazyInit := func() { |
| once.Do(func() { |
| messageName := fd.Message().FullName() |
| messageType, _ = protoregistry.GlobalTypes.FindMessageByName(messageName) |
| if messageType == nil { |
| panic(fmt.Sprintf("weak message %v for field %v is not linked in", messageName, fd.FullName())) |
| } |
| }) |
| } |
| |
| num := fd.Number() |
| return fieldInfo{ |
| fieldDesc: fd, |
| has: func(p pointer) bool { |
| if p.IsNil() { |
| return false |
| } |
| _, ok := p.Apply(weakOffset).WeakFields().get(num) |
| return ok |
| }, |
| clear: func(p pointer) { |
| p.Apply(weakOffset).WeakFields().clear(num) |
| }, |
| get: func(p pointer) protoreflect.Value { |
| lazyInit() |
| if p.IsNil() { |
| return protoreflect.ValueOfMessage(messageType.Zero()) |
| } |
| m, ok := p.Apply(weakOffset).WeakFields().get(num) |
| if !ok { |
| return protoreflect.ValueOfMessage(messageType.Zero()) |
| } |
| return protoreflect.ValueOfMessage(m.ProtoReflect()) |
| }, |
| set: func(p pointer, v protoreflect.Value) { |
| lazyInit() |
| m := v.Message() |
| if m.Descriptor() != messageType.Descriptor() { |
| if got, want := m.Descriptor().FullName(), messageType.Descriptor().FullName(); got != want { |
| panic(fmt.Sprintf("field %v has mismatching message descriptor: got %v, want %v", fd.FullName(), got, want)) |
| } |
| panic(fmt.Sprintf("field %v has mismatching message descriptor: %v", fd.FullName(), m.Descriptor().FullName())) |
| } |
| p.Apply(weakOffset).WeakFields().set(num, m.Interface()) |
| }, |
| mutable: func(p pointer) protoreflect.Value { |
| lazyInit() |
| fs := p.Apply(weakOffset).WeakFields() |
| m, ok := fs.get(num) |
| if !ok { |
| m = messageType.New().Interface() |
| fs.set(num, m) |
| } |
| return protoreflect.ValueOfMessage(m.ProtoReflect()) |
| }, |
| newMessage: func() protoreflect.Message { |
| lazyInit() |
| return messageType.New() |
| }, |
| newField: func() protoreflect.Value { |
| lazyInit() |
| return protoreflect.ValueOfMessage(messageType.New()) |
| }, |
| } |
| } |
| |
| func fieldInfoForMessage(fd protoreflect.FieldDescriptor, fs reflect.StructField, x exporter) fieldInfo { |
| ft := fs.Type |
| conv := NewConverter(ft, fd) |
| |
| // TODO: Implement unsafe fast path? |
| fieldOffset := offsetOf(fs, x) |
| return fieldInfo{ |
| fieldDesc: fd, |
| has: func(p pointer) bool { |
| if p.IsNil() { |
| return false |
| } |
| rv := p.Apply(fieldOffset).AsValueOf(fs.Type).Elem() |
| if fs.Type.Kind() != reflect.Ptr { |
| return !isZero(rv) |
| } |
| return !rv.IsNil() |
| }, |
| clear: func(p pointer) { |
| rv := p.Apply(fieldOffset).AsValueOf(fs.Type).Elem() |
| rv.Set(reflect.Zero(rv.Type())) |
| }, |
| get: func(p pointer) protoreflect.Value { |
| if p.IsNil() { |
| return conv.Zero() |
| } |
| rv := p.Apply(fieldOffset).AsValueOf(fs.Type).Elem() |
| return conv.PBValueOf(rv) |
| }, |
| set: func(p pointer, v protoreflect.Value) { |
| rv := p.Apply(fieldOffset).AsValueOf(fs.Type).Elem() |
| rv.Set(conv.GoValueOf(v)) |
| if fs.Type.Kind() == reflect.Ptr && rv.IsNil() { |
| panic(fmt.Sprintf("field %v has invalid nil pointer", fd.FullName())) |
| } |
| }, |
| mutable: func(p pointer) protoreflect.Value { |
| rv := p.Apply(fieldOffset).AsValueOf(fs.Type).Elem() |
| if fs.Type.Kind() == reflect.Ptr && rv.IsNil() { |
| rv.Set(conv.GoValueOf(conv.New())) |
| } |
| return conv.PBValueOf(rv) |
| }, |
| newMessage: func() protoreflect.Message { |
| return conv.New().Message() |
| }, |
| newField: func() protoreflect.Value { |
| return conv.New() |
| }, |
| } |
| } |
| |
| type oneofInfo struct { |
| oneofDesc protoreflect.OneofDescriptor |
| which func(pointer) protoreflect.FieldNumber |
| } |
| |
| func makeOneofInfo(od protoreflect.OneofDescriptor, si structInfo, x exporter) *oneofInfo { |
| oi := &oneofInfo{oneofDesc: od} |
| if od.IsSynthetic() { |
| fs := si.fieldsByNumber[od.Fields().Get(0).Number()] |
| fieldOffset := offsetOf(fs, x) |
| oi.which = func(p pointer) protoreflect.FieldNumber { |
| if p.IsNil() { |
| return 0 |
| } |
| rv := p.Apply(fieldOffset).AsValueOf(fs.Type).Elem() |
| if rv.IsNil() { // valid on either *T or []byte |
| return 0 |
| } |
| return od.Fields().Get(0).Number() |
| } |
| } else { |
| fs := si.oneofsByName[od.Name()] |
| fieldOffset := offsetOf(fs, x) |
| oi.which = func(p pointer) protoreflect.FieldNumber { |
| if p.IsNil() { |
| return 0 |
| } |
| rv := p.Apply(fieldOffset).AsValueOf(fs.Type).Elem() |
| if rv.IsNil() { |
| return 0 |
| } |
| rv = rv.Elem() |
| if rv.IsNil() { |
| return 0 |
| } |
| return si.oneofWrappersByType[rv.Type().Elem()] |
| } |
| } |
| return oi |
| } |
| |
| // isZero is identical to reflect.Value.IsZero. |
| // TODO: Remove this when Go1.13 is the minimally supported Go version. |
| func isZero(v reflect.Value) bool { |
| switch v.Kind() { |
| case reflect.Bool: |
| return !v.Bool() |
| case reflect.Int, reflect.Int8, reflect.Int16, reflect.Int32, reflect.Int64: |
| return v.Int() == 0 |
| case reflect.Uint, reflect.Uint8, reflect.Uint16, reflect.Uint32, reflect.Uint64, reflect.Uintptr: |
| return v.Uint() == 0 |
| case reflect.Float32, reflect.Float64: |
| return math.Float64bits(v.Float()) == 0 |
| case reflect.Complex64, reflect.Complex128: |
| c := v.Complex() |
| return math.Float64bits(real(c)) == 0 && math.Float64bits(imag(c)) == 0 |
| case reflect.Array: |
| for i := 0; i < v.Len(); i++ { |
| if !isZero(v.Index(i)) { |
| return false |
| } |
| } |
| return true |
| case reflect.Chan, reflect.Func, reflect.Interface, reflect.Map, reflect.Ptr, reflect.Slice, reflect.UnsafePointer: |
| return v.IsNil() |
| case reflect.String: |
| return v.Len() == 0 |
| case reflect.Struct: |
| for i := 0; i < v.NumField(); i++ { |
| if !isZero(v.Field(i)) { |
| return false |
| } |
| } |
| return true |
| default: |
| panic(&reflect.ValueError{"reflect.Value.IsZero", v.Kind()}) |
| } |
| } |
