| // Copyright 2019 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/internal/detrand" | 
 | 	"google.golang.org/protobuf/internal/pragma" | 
 | 	"google.golang.org/protobuf/reflect/protoreflect" | 
 | ) | 
 |  | 
 | type reflectMessageInfo struct { | 
 | 	fields map[protoreflect.FieldNumber]*fieldInfo | 
 | 	oneofs map[protoreflect.Name]*oneofInfo | 
 |  | 
 | 	// fieldTypes contains the zero value of an enum or message field. | 
 | 	// For lists, it contains the element type. | 
 | 	// For maps, it contains the entry value type. | 
 | 	fieldTypes map[protoreflect.FieldNumber]any | 
 |  | 
 | 	// denseFields is a subset of fields where: | 
 | 	//	0 < fieldDesc.Number() < len(denseFields) | 
 | 	// It provides faster access to the fieldInfo, but may be incomplete. | 
 | 	denseFields []*fieldInfo | 
 |  | 
 | 	// rangeInfos is a list of all fields (not belonging to a oneof) and oneofs. | 
 | 	rangeInfos []any // either *fieldInfo or *oneofInfo | 
 |  | 
 | 	getUnknown   func(pointer) protoreflect.RawFields | 
 | 	setUnknown   func(pointer, protoreflect.RawFields) | 
 | 	extensionMap func(pointer) *extensionMap | 
 |  | 
 | 	nilMessage atomicNilMessage | 
 | } | 
 |  | 
 | // makeReflectFuncs generates the set of functions to support reflection. | 
 | func (mi *MessageInfo) makeReflectFuncs(t reflect.Type, si structInfo) { | 
 | 	mi.makeKnownFieldsFunc(si) | 
 | 	mi.makeUnknownFieldsFunc(t, si) | 
 | 	mi.makeExtensionFieldsFunc(t, si) | 
 | 	mi.makeFieldTypes(si) | 
 | } | 
 |  | 
 | // makeKnownFieldsFunc generates functions for operations that can be performed | 
 | // on each protobuf message field. It takes in a reflect.Type representing the | 
 | // Go struct and matches message fields with struct fields. | 
 | // | 
 | // This code assumes that the struct is well-formed and panics if there are | 
 | // any discrepancies. | 
 | func (mi *MessageInfo) makeKnownFieldsFunc(si structInfo) { | 
 | 	mi.fields = map[protoreflect.FieldNumber]*fieldInfo{} | 
 | 	md := mi.Desc | 
 | 	fds := md.Fields() | 
 | 	for i := 0; i < fds.Len(); i++ { | 
 | 		fd := fds.Get(i) | 
 | 		fs := si.fieldsByNumber[fd.Number()] | 
 | 		isOneof := fd.ContainingOneof() != nil && !fd.ContainingOneof().IsSynthetic() | 
 | 		if isOneof { | 
 | 			fs = si.oneofsByName[fd.ContainingOneof().Name()] | 
 | 		} | 
 | 		var fi fieldInfo | 
 | 		switch { | 
 | 		case fs.Type == nil: | 
 | 			fi = fieldInfoForMissing(fd) // never occurs for officially generated message types | 
 | 		case isOneof: | 
 | 			fi = fieldInfoForOneof(fd, fs, mi.Exporter, si.oneofWrappersByNumber[fd.Number()]) | 
 | 		case fd.IsMap(): | 
 | 			fi = fieldInfoForMap(fd, fs, mi.Exporter) | 
 | 		case fd.IsList(): | 
 | 			fi = fieldInfoForList(fd, fs, mi.Exporter) | 
 | 		case fd.IsWeak(): | 
 | 			fi = fieldInfoForWeakMessage(fd, si.weakOffset) | 
 | 		case fd.Message() != nil: | 
 | 			fi = fieldInfoForMessage(fd, fs, mi.Exporter) | 
 | 		default: | 
 | 			fi = fieldInfoForScalar(fd, fs, mi.Exporter) | 
 | 		} | 
 | 		mi.fields[fd.Number()] = &fi | 
 | 	} | 
 |  | 
 | 	mi.oneofs = map[protoreflect.Name]*oneofInfo{} | 
 | 	for i := 0; i < md.Oneofs().Len(); i++ { | 
 | 		od := md.Oneofs().Get(i) | 
 | 		mi.oneofs[od.Name()] = makeOneofInfo(od, si, mi.Exporter) | 
 | 	} | 
 |  | 
 | 	mi.denseFields = make([]*fieldInfo, fds.Len()*2) | 
 | 	for i := 0; i < fds.Len(); i++ { | 
 | 		if fd := fds.Get(i); int(fd.Number()) < len(mi.denseFields) { | 
 | 			mi.denseFields[fd.Number()] = mi.fields[fd.Number()] | 
 | 		} | 
 | 	} | 
 |  | 
 | 	for i := 0; i < fds.Len(); { | 
 | 		fd := fds.Get(i) | 
 | 		if od := fd.ContainingOneof(); od != nil && !od.IsSynthetic() { | 
 | 			mi.rangeInfos = append(mi.rangeInfos, mi.oneofs[od.Name()]) | 
 | 			i += od.Fields().Len() | 
 | 		} else { | 
 | 			mi.rangeInfos = append(mi.rangeInfos, mi.fields[fd.Number()]) | 
 | 			i++ | 
 | 		} | 
 | 	} | 
 |  | 
 | 	// Introduce instability to iteration order, but keep it deterministic. | 
 | 	if len(mi.rangeInfos) > 1 && detrand.Bool() { | 
 | 		i := detrand.Intn(len(mi.rangeInfos) - 1) | 
 | 		mi.rangeInfos[i], mi.rangeInfos[i+1] = mi.rangeInfos[i+1], mi.rangeInfos[i] | 
 | 	} | 
 | } | 
 |  | 
 | func (mi *MessageInfo) makeUnknownFieldsFunc(t reflect.Type, si structInfo) { | 
 | 	switch { | 
 | 	case si.unknownOffset.IsValid() && si.unknownType == unknownFieldsAType: | 
 | 		// Handle as []byte. | 
 | 		mi.getUnknown = func(p pointer) protoreflect.RawFields { | 
 | 			if p.IsNil() { | 
 | 				return nil | 
 | 			} | 
 | 			return *p.Apply(mi.unknownOffset).Bytes() | 
 | 		} | 
 | 		mi.setUnknown = func(p pointer, b protoreflect.RawFields) { | 
 | 			if p.IsNil() { | 
 | 				panic("invalid SetUnknown on nil Message") | 
 | 			} | 
 | 			*p.Apply(mi.unknownOffset).Bytes() = b | 
 | 		} | 
 | 	case si.unknownOffset.IsValid() && si.unknownType == unknownFieldsBType: | 
 | 		// Handle as *[]byte. | 
 | 		mi.getUnknown = func(p pointer) protoreflect.RawFields { | 
 | 			if p.IsNil() { | 
 | 				return nil | 
 | 			} | 
 | 			bp := p.Apply(mi.unknownOffset).BytesPtr() | 
 | 			if *bp == nil { | 
 | 				return nil | 
 | 			} | 
 | 			return **bp | 
 | 		} | 
 | 		mi.setUnknown = func(p pointer, b protoreflect.RawFields) { | 
 | 			if p.IsNil() { | 
 | 				panic("invalid SetUnknown on nil Message") | 
 | 			} | 
 | 			bp := p.Apply(mi.unknownOffset).BytesPtr() | 
 | 			if *bp == nil { | 
 | 				*bp = new([]byte) | 
 | 			} | 
 | 			**bp = b | 
 | 		} | 
 | 	default: | 
 | 		mi.getUnknown = func(pointer) protoreflect.RawFields { | 
 | 			return nil | 
 | 		} | 
 | 		mi.setUnknown = func(p pointer, _ protoreflect.RawFields) { | 
 | 			if p.IsNil() { | 
 | 				panic("invalid SetUnknown on nil Message") | 
 | 			} | 
 | 		} | 
 | 	} | 
 | } | 
 |  | 
 | func (mi *MessageInfo) makeExtensionFieldsFunc(t reflect.Type, si structInfo) { | 
 | 	if si.extensionOffset.IsValid() { | 
 | 		mi.extensionMap = func(p pointer) *extensionMap { | 
 | 			if p.IsNil() { | 
 | 				return (*extensionMap)(nil) | 
 | 			} | 
 | 			v := p.Apply(si.extensionOffset).AsValueOf(extensionFieldsType) | 
 | 			return (*extensionMap)(v.Interface().(*map[int32]ExtensionField)) | 
 | 		} | 
 | 	} else { | 
 | 		mi.extensionMap = func(pointer) *extensionMap { | 
 | 			return (*extensionMap)(nil) | 
 | 		} | 
 | 	} | 
 | } | 
 | func (mi *MessageInfo) makeFieldTypes(si structInfo) { | 
 | 	md := mi.Desc | 
 | 	fds := md.Fields() | 
 | 	for i := 0; i < fds.Len(); i++ { | 
 | 		var ft reflect.Type | 
 | 		fd := fds.Get(i) | 
 | 		fs := si.fieldsByNumber[fd.Number()] | 
 | 		isOneof := fd.ContainingOneof() != nil && !fd.ContainingOneof().IsSynthetic() | 
 | 		if isOneof { | 
 | 			fs = si.oneofsByName[fd.ContainingOneof().Name()] | 
 | 		} | 
 | 		var isMessage bool | 
 | 		switch { | 
 | 		case fs.Type == nil: | 
 | 			continue // never occurs for officially generated message types | 
 | 		case isOneof: | 
 | 			if fd.Enum() != nil || fd.Message() != nil { | 
 | 				ft = si.oneofWrappersByNumber[fd.Number()].Field(0).Type | 
 | 			} | 
 | 		case fd.IsMap(): | 
 | 			if fd.MapValue().Enum() != nil || fd.MapValue().Message() != nil { | 
 | 				ft = fs.Type.Elem() | 
 | 			} | 
 | 			isMessage = fd.MapValue().Message() != nil | 
 | 		case fd.IsList(): | 
 | 			if fd.Enum() != nil || fd.Message() != nil { | 
 | 				ft = fs.Type.Elem() | 
 |  | 
 | 				if ft.Kind() == reflect.Slice { | 
 | 					ft = ft.Elem() | 
 | 				} | 
 |  | 
 | 			} | 
 | 			isMessage = fd.Message() != nil | 
 | 		case fd.Enum() != nil: | 
 | 			ft = fs.Type | 
 | 			if fd.HasPresence() && ft.Kind() == reflect.Ptr { | 
 | 				ft = ft.Elem() | 
 | 			} | 
 | 		case fd.Message() != nil: | 
 | 			ft = fs.Type | 
 | 			if fd.IsWeak() { | 
 | 				ft = nil | 
 | 			} | 
 | 			isMessage = true | 
 | 		} | 
 | 		if isMessage && ft != nil && ft.Kind() != reflect.Ptr { | 
 | 			ft = reflect.PtrTo(ft) // never occurs for officially generated message types | 
 | 		} | 
 | 		if ft != nil { | 
 | 			if mi.fieldTypes == nil { | 
 | 				mi.fieldTypes = make(map[protoreflect.FieldNumber]any) | 
 | 			} | 
 | 			mi.fieldTypes[fd.Number()] = reflect.Zero(ft).Interface() | 
 | 		} | 
 | 	} | 
 | } | 
 |  | 
 | type extensionMap map[int32]ExtensionField | 
 |  | 
 | func (m *extensionMap) Range(f func(protoreflect.FieldDescriptor, protoreflect.Value) bool) { | 
 | 	if m != nil { | 
 | 		for _, x := range *m { | 
 | 			xd := x.Type().TypeDescriptor() | 
 | 			v := x.Value() | 
 | 			if xd.IsList() && v.List().Len() == 0 { | 
 | 				continue | 
 | 			} | 
 | 			if !f(xd, v) { | 
 | 				return | 
 | 			} | 
 | 		} | 
 | 	} | 
 | } | 
 | func (m *extensionMap) Has(xd protoreflect.ExtensionTypeDescriptor) (ok bool) { | 
 | 	if m == nil { | 
 | 		return false | 
 | 	} | 
 | 	x, ok := (*m)[int32(xd.Number())] | 
 | 	if !ok { | 
 | 		return false | 
 | 	} | 
 | 	if x.isUnexpandedLazy() { | 
 | 		// Avoid calling x.Value(), which triggers a lazy unmarshal. | 
 | 		return true | 
 | 	} | 
 | 	switch { | 
 | 	case xd.IsList(): | 
 | 		return x.Value().List().Len() > 0 | 
 | 	case xd.IsMap(): | 
 | 		return x.Value().Map().Len() > 0 | 
 | 	} | 
 | 	return true | 
 | } | 
 | func (m *extensionMap) Clear(xd protoreflect.ExtensionTypeDescriptor) { | 
 | 	delete(*m, int32(xd.Number())) | 
 | } | 
 | func (m *extensionMap) Get(xd protoreflect.ExtensionTypeDescriptor) protoreflect.Value { | 
 | 	if m != nil { | 
 | 		if x, ok := (*m)[int32(xd.Number())]; ok { | 
 | 			return x.Value() | 
 | 		} | 
 | 	} | 
 | 	return xd.Type().Zero() | 
 | } | 
 | func (m *extensionMap) Set(xd protoreflect.ExtensionTypeDescriptor, v protoreflect.Value) { | 
 | 	xt := xd.Type() | 
 | 	isValid := true | 
 | 	switch { | 
 | 	case !xt.IsValidValue(v): | 
 | 		isValid = false | 
 | 	case xd.IsList(): | 
 | 		isValid = v.List().IsValid() | 
 | 	case xd.IsMap(): | 
 | 		isValid = v.Map().IsValid() | 
 | 	case xd.Message() != nil: | 
 | 		isValid = v.Message().IsValid() | 
 | 	} | 
 | 	if !isValid { | 
 | 		panic(fmt.Sprintf("%v: assigning invalid value", xd.FullName())) | 
 | 	} | 
 |  | 
 | 	if *m == nil { | 
 | 		*m = make(map[int32]ExtensionField) | 
 | 	} | 
 | 	var x ExtensionField | 
 | 	x.Set(xt, v) | 
 | 	(*m)[int32(xd.Number())] = x | 
 | } | 
 | func (m *extensionMap) Mutable(xd protoreflect.ExtensionTypeDescriptor) protoreflect.Value { | 
 | 	if xd.Kind() != protoreflect.MessageKind && xd.Kind() != protoreflect.GroupKind && !xd.IsList() && !xd.IsMap() { | 
 | 		panic("invalid Mutable on field with non-composite type") | 
 | 	} | 
 | 	if x, ok := (*m)[int32(xd.Number())]; ok { | 
 | 		return x.Value() | 
 | 	} | 
 | 	v := xd.Type().New() | 
 | 	m.Set(xd, v) | 
 | 	return v | 
 | } | 
 |  | 
 | // MessageState is a data structure that is nested as the first field in a | 
 | // concrete message. It provides a way to implement the ProtoReflect method | 
 | // in an allocation-free way without needing to have a shadow Go type generated | 
 | // for every message type. This technique only works using unsafe. | 
 | // | 
 | // Example generated code: | 
 | // | 
 | //	type M struct { | 
 | //		state protoimpl.MessageState | 
 | // | 
 | //		Field1 int32 | 
 | //		Field2 string | 
 | //		Field3 *BarMessage | 
 | //		... | 
 | //	} | 
 | // | 
 | //	func (m *M) ProtoReflect() protoreflect.Message { | 
 | //		mi := &file_fizz_buzz_proto_msgInfos[5] | 
 | //		if protoimpl.UnsafeEnabled && m != nil { | 
 | //			ms := protoimpl.X.MessageStateOf(Pointer(m)) | 
 | //			if ms.LoadMessageInfo() == nil { | 
 | //				ms.StoreMessageInfo(mi) | 
 | //			} | 
 | //			return ms | 
 | //		} | 
 | //		return mi.MessageOf(m) | 
 | //	} | 
 | // | 
 | // The MessageState type holds a *MessageInfo, which must be atomically set to | 
 | // the message info associated with a given message instance. | 
 | // By unsafely converting a *M into a *MessageState, the MessageState object | 
 | // has access to all the information needed to implement protobuf reflection. | 
 | // It has access to the message info as its first field, and a pointer to the | 
 | // MessageState is identical to a pointer to the concrete message value. | 
 | // | 
 | // Requirements: | 
 | //   - The type M must implement protoreflect.ProtoMessage. | 
 | //   - The address of m must not be nil. | 
 | //   - The address of m and the address of m.state must be equal, | 
 | //     even though they are different Go types. | 
 | type MessageState struct { | 
 | 	pragma.NoUnkeyedLiterals | 
 | 	pragma.DoNotCompare | 
 | 	pragma.DoNotCopy | 
 |  | 
 | 	atomicMessageInfo *MessageInfo | 
 | } | 
 |  | 
 | type messageState MessageState | 
 |  | 
 | var ( | 
 | 	_ protoreflect.Message = (*messageState)(nil) | 
 | 	_ unwrapper            = (*messageState)(nil) | 
 | ) | 
 |  | 
 | // messageDataType is a tuple of a pointer to the message data and | 
 | // a pointer to the message type. It is a generalized way of providing a | 
 | // reflective view over a message instance. The disadvantage of this approach | 
 | // is the need to allocate this tuple of 16B. | 
 | type messageDataType struct { | 
 | 	p  pointer | 
 | 	mi *MessageInfo | 
 | } | 
 |  | 
 | type ( | 
 | 	messageReflectWrapper messageDataType | 
 | 	messageIfaceWrapper   messageDataType | 
 | ) | 
 |  | 
 | var ( | 
 | 	_ protoreflect.Message      = (*messageReflectWrapper)(nil) | 
 | 	_ unwrapper                 = (*messageReflectWrapper)(nil) | 
 | 	_ protoreflect.ProtoMessage = (*messageIfaceWrapper)(nil) | 
 | 	_ unwrapper                 = (*messageIfaceWrapper)(nil) | 
 | ) | 
 |  | 
 | // MessageOf returns a reflective view over a message. The input must be a | 
 | // pointer to a named Go struct. If the provided type has a ProtoReflect method, | 
 | // it must be implemented by calling this method. | 
 | func (mi *MessageInfo) MessageOf(m any) protoreflect.Message { | 
 | 	if reflect.TypeOf(m) != mi.GoReflectType { | 
 | 		panic(fmt.Sprintf("type mismatch: got %T, want %v", m, mi.GoReflectType)) | 
 | 	} | 
 | 	p := pointerOfIface(m) | 
 | 	if p.IsNil() { | 
 | 		return mi.nilMessage.Init(mi) | 
 | 	} | 
 | 	return &messageReflectWrapper{p, mi} | 
 | } | 
 |  | 
 | func (m *messageReflectWrapper) pointer() pointer          { return m.p } | 
 | func (m *messageReflectWrapper) messageInfo() *MessageInfo { return m.mi } | 
 |  | 
 | // Reset implements the v1 proto.Message.Reset method. | 
 | func (m *messageIfaceWrapper) Reset() { | 
 | 	if mr, ok := m.protoUnwrap().(interface{ Reset() }); ok { | 
 | 		mr.Reset() | 
 | 		return | 
 | 	} | 
 | 	rv := reflect.ValueOf(m.protoUnwrap()) | 
 | 	if rv.Kind() == reflect.Ptr && !rv.IsNil() { | 
 | 		rv.Elem().Set(reflect.Zero(rv.Type().Elem())) | 
 | 	} | 
 | } | 
 | func (m *messageIfaceWrapper) ProtoReflect() protoreflect.Message { | 
 | 	return (*messageReflectWrapper)(m) | 
 | } | 
 | func (m *messageIfaceWrapper) protoUnwrap() any { | 
 | 	return m.p.AsIfaceOf(m.mi.GoReflectType.Elem()) | 
 | } | 
 |  | 
 | // checkField verifies that the provided field descriptor is valid. | 
 | // Exactly one of the returned values is populated. | 
 | func (mi *MessageInfo) checkField(fd protoreflect.FieldDescriptor) (*fieldInfo, protoreflect.ExtensionTypeDescriptor) { | 
 | 	var fi *fieldInfo | 
 | 	if n := fd.Number(); 0 < n && int(n) < len(mi.denseFields) { | 
 | 		fi = mi.denseFields[n] | 
 | 	} else { | 
 | 		fi = mi.fields[n] | 
 | 	} | 
 | 	if fi != nil { | 
 | 		if fi.fieldDesc != fd { | 
 | 			if got, want := fd.FullName(), fi.fieldDesc.FullName(); got != want { | 
 | 				panic(fmt.Sprintf("mismatching field: got %v, want %v", got, want)) | 
 | 			} | 
 | 			panic(fmt.Sprintf("mismatching field: %v", fd.FullName())) | 
 | 		} | 
 | 		return fi, nil | 
 | 	} | 
 |  | 
 | 	if fd.IsExtension() { | 
 | 		if got, want := fd.ContainingMessage().FullName(), mi.Desc.FullName(); got != want { | 
 | 			// TODO: Should this be exact containing message descriptor match? | 
 | 			panic(fmt.Sprintf("extension %v has mismatching containing message: got %v, want %v", fd.FullName(), got, want)) | 
 | 		} | 
 | 		if !mi.Desc.ExtensionRanges().Has(fd.Number()) { | 
 | 			panic(fmt.Sprintf("extension %v extends %v outside the extension range", fd.FullName(), mi.Desc.FullName())) | 
 | 		} | 
 | 		xtd, ok := fd.(protoreflect.ExtensionTypeDescriptor) | 
 | 		if !ok { | 
 | 			panic(fmt.Sprintf("extension %v does not implement protoreflect.ExtensionTypeDescriptor", fd.FullName())) | 
 | 		} | 
 | 		return nil, xtd | 
 | 	} | 
 | 	panic(fmt.Sprintf("field %v is invalid", fd.FullName())) | 
 | } |