diff options
Diffstat (limited to 'vendor/google.golang.org/protobuf/internal/impl/message_reflect_field.go')
-rw-r--r-- | vendor/google.golang.org/protobuf/internal/impl/message_reflect_field.go | 466 |
1 files changed, 466 insertions, 0 deletions
diff --git a/vendor/google.golang.org/protobuf/internal/impl/message_reflect_field.go b/vendor/google.golang.org/protobuf/internal/impl/message_reflect_field.go new file mode 100644 index 000000000..23124a86e --- /dev/null +++ b/vendor/google.golang.org/protobuf/internal/impl/message_reflect_field.go @@ -0,0 +1,466 @@ +// 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" + pref "google.golang.org/protobuf/reflect/protoreflect" + preg "google.golang.org/protobuf/reflect/protoregistry" +) + +type fieldInfo struct { + fieldDesc pref.FieldDescriptor + + // These fields are used for protobuf reflection support. + has func(pointer) bool + clear func(pointer) + get func(pointer) pref.Value + set func(pointer, pref.Value) + mutable func(pointer) pref.Value + newMessage func() pref.Message + newField func() pref.Value +} + +func fieldInfoForOneof(fd pref.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) pref.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 pref.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) pref.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.IsNil() { + rv.Set(conv.GoValueOf(pref.ValueOfMessage(conv.New().Message()))) + } + return conv.PBValueOf(rv) + }, + newMessage: func() pref.Message { + return conv.New().Message() + }, + newField: func() pref.Value { + return conv.New() + }, + } +} + +func fieldInfoForMap(fd pref.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) pref.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 pref.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) pref.Value { + v := p.Apply(fieldOffset).AsValueOf(fs.Type).Elem() + if v.IsNil() { + v.Set(reflect.MakeMap(fs.Type)) + } + return conv.PBValueOf(v) + }, + newField: func() pref.Value { + return conv.New() + }, + } +} + +func fieldInfoForList(fd pref.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) pref.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 pref.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) pref.Value { + v := p.Apply(fieldOffset).AsValueOf(fs.Type) + return conv.PBValueOf(v) + }, + newField: func() pref.Value { + return conv.New() + }, + } +} + +var ( + nilBytes = reflect.ValueOf([]byte(nil)) + emptyBytes = reflect.ValueOf([]byte{}) +) + +func fieldInfoForScalar(fd pref.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 { + panic(fmt.Sprintf("field %v has invalid type: got %v, want pointer", fd.FullName(), ft)) + } + 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) pref.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 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 isBytes && rv.Len() == 0 { + if nullable { + rv.Set(emptyBytes) // preserve presence + } else { + rv.Set(nilBytes) // do not preserve presence + } + } + }, + newField: func() pref.Value { + return conv.New() + }, + } +} + +func fieldInfoForWeakMessage(fd pref.FieldDescriptor, weakOffset offset) fieldInfo { + if !flags.ProtoLegacy { + panic("no support for proto1 weak fields") + } + + var once sync.Once + var messageType pref.MessageType + lazyInit := func() { + once.Do(func() { + messageName := fd.Message().FullName() + messageType, _ = preg.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) pref.Value { + lazyInit() + if p.IsNil() { + return pref.ValueOfMessage(messageType.Zero()) + } + m, ok := p.Apply(weakOffset).WeakFields().get(num) + if !ok { + return pref.ValueOfMessage(messageType.Zero()) + } + return pref.ValueOfMessage(m.ProtoReflect()) + }, + set: func(p pointer, v pref.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) pref.Value { + lazyInit() + fs := p.Apply(weakOffset).WeakFields() + m, ok := fs.get(num) + if !ok { + m = messageType.New().Interface() + fs.set(num, m) + } + return pref.ValueOfMessage(m.ProtoReflect()) + }, + newMessage: func() pref.Message { + lazyInit() + return messageType.New() + }, + newField: func() pref.Value { + lazyInit() + return pref.ValueOfMessage(messageType.New()) + }, + } +} + +func fieldInfoForMessage(fd pref.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() + 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) pref.Value { + if p.IsNil() { + return conv.Zero() + } + rv := p.Apply(fieldOffset).AsValueOf(fs.Type).Elem() + 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(fmt.Sprintf("field %v has invalid nil pointer", fd.FullName())) + } + }, + mutable: func(p pointer) pref.Value { + rv := p.Apply(fieldOffset).AsValueOf(fs.Type).Elem() + if rv.IsNil() { + rv.Set(conv.GoValueOf(conv.New())) + } + return conv.PBValueOf(rv) + }, + newMessage: func() pref.Message { + return conv.New().Message() + }, + newField: func() pref.Value { + return conv.New() + }, + } +} + +type oneofInfo struct { + oneofDesc pref.OneofDescriptor + which func(pointer) pref.FieldNumber +} + +func makeOneofInfo(od pref.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) pref.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) pref.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 +} |