aboutsummaryrefslogtreecommitdiff
path: root/internal/impl/legacy_message.go
diff options
context:
space:
mode:
Diffstat (limited to 'internal/impl/legacy_message.go')
-rw-r--r--internal/impl/legacy_message.go565
1 files changed, 565 insertions, 0 deletions
diff --git a/internal/impl/legacy_message.go b/internal/impl/legacy_message.go
new file mode 100644
index 00000000..029feeef
--- /dev/null
+++ b/internal/impl/legacy_message.go
@@ -0,0 +1,565 @@
+// 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"
+ "strings"
+ "sync"
+
+ "google.golang.org/protobuf/internal/descopts"
+ ptag "google.golang.org/protobuf/internal/encoding/tag"
+ "google.golang.org/protobuf/internal/errors"
+ "google.golang.org/protobuf/internal/filedesc"
+ "google.golang.org/protobuf/internal/strs"
+ "google.golang.org/protobuf/reflect/protoreflect"
+ pref "google.golang.org/protobuf/reflect/protoreflect"
+ "google.golang.org/protobuf/runtime/protoiface"
+ piface "google.golang.org/protobuf/runtime/protoiface"
+)
+
+// legacyWrapMessage wraps v as a protoreflect.Message,
+// where v must be a *struct kind and not implement the v2 API already.
+func legacyWrapMessage(v reflect.Value) pref.Message {
+ t := v.Type()
+ if t.Kind() != reflect.Ptr || t.Elem().Kind() != reflect.Struct {
+ return aberrantMessage{v: v}
+ }
+ mt := legacyLoadMessageInfo(t, "")
+ return mt.MessageOf(v.Interface())
+}
+
+// legacyLoadMessageType dynamically loads a protoreflect.Type for t,
+// where t must be not implement the v2 API already.
+// The provided name is used if it cannot be determined from the message.
+func legacyLoadMessageType(t reflect.Type, name pref.FullName) protoreflect.MessageType {
+ if t.Kind() != reflect.Ptr || t.Elem().Kind() != reflect.Struct {
+ return aberrantMessageType{t}
+ }
+ return legacyLoadMessageInfo(t, name)
+}
+
+var legacyMessageTypeCache sync.Map // map[reflect.Type]*MessageInfo
+
+// legacyLoadMessageInfo dynamically loads a *MessageInfo for t,
+// where t must be a *struct kind and not implement the v2 API already.
+// The provided name is used if it cannot be determined from the message.
+func legacyLoadMessageInfo(t reflect.Type, name pref.FullName) *MessageInfo {
+ // Fast-path: check if a MessageInfo is cached for this concrete type.
+ if mt, ok := legacyMessageTypeCache.Load(t); ok {
+ return mt.(*MessageInfo)
+ }
+
+ // Slow-path: derive message descriptor and initialize MessageInfo.
+ mi := &MessageInfo{
+ Desc: legacyLoadMessageDesc(t, name),
+ GoReflectType: t,
+ }
+
+ var hasMarshal, hasUnmarshal bool
+ v := reflect.Zero(t).Interface()
+ if _, hasMarshal = v.(legacyMarshaler); hasMarshal {
+ mi.methods.Marshal = legacyMarshal
+
+ // We have no way to tell whether the type's Marshal method
+ // supports deterministic serialization or not, but this
+ // preserves the v1 implementation's behavior of always
+ // calling Marshal methods when present.
+ mi.methods.Flags |= piface.SupportMarshalDeterministic
+ }
+ if _, hasUnmarshal = v.(legacyUnmarshaler); hasUnmarshal {
+ mi.methods.Unmarshal = legacyUnmarshal
+ }
+ if _, hasMerge := v.(legacyMerger); hasMerge || (hasMarshal && hasUnmarshal) {
+ mi.methods.Merge = legacyMerge
+ }
+
+ if mi, ok := legacyMessageTypeCache.LoadOrStore(t, mi); ok {
+ return mi.(*MessageInfo)
+ }
+ return mi
+}
+
+var legacyMessageDescCache sync.Map // map[reflect.Type]protoreflect.MessageDescriptor
+
+// LegacyLoadMessageDesc returns an MessageDescriptor derived from the Go type,
+// which should be a *struct kind and must not implement the v2 API already.
+//
+// This is exported for testing purposes.
+func LegacyLoadMessageDesc(t reflect.Type) pref.MessageDescriptor {
+ return legacyLoadMessageDesc(t, "")
+}
+func legacyLoadMessageDesc(t reflect.Type, name pref.FullName) pref.MessageDescriptor {
+ // Fast-path: check if a MessageDescriptor is cached for this concrete type.
+ if mi, ok := legacyMessageDescCache.Load(t); ok {
+ return mi.(pref.MessageDescriptor)
+ }
+
+ // Slow-path: initialize MessageDescriptor from the raw descriptor.
+ mv := reflect.Zero(t).Interface()
+ if _, ok := mv.(pref.ProtoMessage); ok {
+ panic(fmt.Sprintf("%v already implements proto.Message", t))
+ }
+ mdV1, ok := mv.(messageV1)
+ if !ok {
+ return aberrantLoadMessageDesc(t, name)
+ }
+
+ // If this is a dynamic message type where there isn't a 1-1 mapping between
+ // Go and protobuf types, calling the Descriptor method on the zero value of
+ // the message type isn't likely to work. If it panics, swallow the panic and
+ // continue as if the Descriptor method wasn't present.
+ b, idxs := func() ([]byte, []int) {
+ defer func() {
+ recover()
+ }()
+ return mdV1.Descriptor()
+ }()
+ if b == nil {
+ return aberrantLoadMessageDesc(t, name)
+ }
+
+ // If the Go type has no fields, then this might be a proto3 empty message
+ // from before the size cache was added. If there are any fields, check to
+ // see that at least one of them looks like something we generated.
+ if t.Elem().Kind() == reflect.Struct {
+ if nfield := t.Elem().NumField(); nfield > 0 {
+ hasProtoField := false
+ for i := 0; i < nfield; i++ {
+ f := t.Elem().Field(i)
+ if f.Tag.Get("protobuf") != "" || f.Tag.Get("protobuf_oneof") != "" || strings.HasPrefix(f.Name, "XXX_") {
+ hasProtoField = true
+ break
+ }
+ }
+ if !hasProtoField {
+ return aberrantLoadMessageDesc(t, name)
+ }
+ }
+ }
+
+ md := legacyLoadFileDesc(b).Messages().Get(idxs[0])
+ for _, i := range idxs[1:] {
+ md = md.Messages().Get(i)
+ }
+ if name != "" && md.FullName() != name {
+ panic(fmt.Sprintf("mismatching message name: got %v, want %v", md.FullName(), name))
+ }
+ if md, ok := legacyMessageDescCache.LoadOrStore(t, md); ok {
+ return md.(protoreflect.MessageDescriptor)
+ }
+ return md
+}
+
+var (
+ aberrantMessageDescLock sync.Mutex
+ aberrantMessageDescCache map[reflect.Type]protoreflect.MessageDescriptor
+)
+
+// aberrantLoadMessageDesc returns an MessageDescriptor derived from the Go type,
+// which must not implement protoreflect.ProtoMessage or messageV1.
+//
+// This is a best-effort derivation of the message descriptor using the protobuf
+// tags on the struct fields.
+func aberrantLoadMessageDesc(t reflect.Type, name pref.FullName) pref.MessageDescriptor {
+ aberrantMessageDescLock.Lock()
+ defer aberrantMessageDescLock.Unlock()
+ if aberrantMessageDescCache == nil {
+ aberrantMessageDescCache = make(map[reflect.Type]protoreflect.MessageDescriptor)
+ }
+ return aberrantLoadMessageDescReentrant(t, name)
+}
+func aberrantLoadMessageDescReentrant(t reflect.Type, name pref.FullName) pref.MessageDescriptor {
+ // Fast-path: check if an MessageDescriptor is cached for this concrete type.
+ if md, ok := aberrantMessageDescCache[t]; ok {
+ return md
+ }
+
+ // Slow-path: construct a descriptor from the Go struct type (best-effort).
+ // Cache the MessageDescriptor early on so that we can resolve internal
+ // cyclic references.
+ md := &filedesc.Message{L2: new(filedesc.MessageL2)}
+ md.L0.FullName = aberrantDeriveMessageName(t, name)
+ md.L0.ParentFile = filedesc.SurrogateProto2
+ aberrantMessageDescCache[t] = md
+
+ if t.Kind() != reflect.Ptr || t.Elem().Kind() != reflect.Struct {
+ return md
+ }
+
+ // Try to determine if the message is using proto3 by checking scalars.
+ for i := 0; i < t.Elem().NumField(); i++ {
+ f := t.Elem().Field(i)
+ if tag := f.Tag.Get("protobuf"); tag != "" {
+ switch f.Type.Kind() {
+ case reflect.Bool, reflect.Int32, reflect.Int64, reflect.Uint32, reflect.Uint64, reflect.Float32, reflect.Float64, reflect.String:
+ md.L0.ParentFile = filedesc.SurrogateProto3
+ }
+ for _, s := range strings.Split(tag, ",") {
+ if s == "proto3" {
+ md.L0.ParentFile = filedesc.SurrogateProto3
+ }
+ }
+ }
+ }
+
+ // Obtain a list of oneof wrapper types.
+ var oneofWrappers []reflect.Type
+ for _, method := range []string{"XXX_OneofFuncs", "XXX_OneofWrappers"} {
+ if fn, ok := t.MethodByName(method); ok {
+ for _, v := range fn.Func.Call([]reflect.Value{reflect.Zero(fn.Type.In(0))}) {
+ if vs, ok := v.Interface().([]interface{}); ok {
+ for _, v := range vs {
+ oneofWrappers = append(oneofWrappers, reflect.TypeOf(v))
+ }
+ }
+ }
+ }
+ }
+
+ // Obtain a list of the extension ranges.
+ if fn, ok := t.MethodByName("ExtensionRangeArray"); ok {
+ vs := fn.Func.Call([]reflect.Value{reflect.Zero(fn.Type.In(0))})[0]
+ for i := 0; i < vs.Len(); i++ {
+ v := vs.Index(i)
+ md.L2.ExtensionRanges.List = append(md.L2.ExtensionRanges.List, [2]pref.FieldNumber{
+ pref.FieldNumber(v.FieldByName("Start").Int()),
+ pref.FieldNumber(v.FieldByName("End").Int() + 1),
+ })
+ md.L2.ExtensionRangeOptions = append(md.L2.ExtensionRangeOptions, nil)
+ }
+ }
+
+ // Derive the message fields by inspecting the struct fields.
+ for i := 0; i < t.Elem().NumField(); i++ {
+ f := t.Elem().Field(i)
+ if tag := f.Tag.Get("protobuf"); tag != "" {
+ tagKey := f.Tag.Get("protobuf_key")
+ tagVal := f.Tag.Get("protobuf_val")
+ aberrantAppendField(md, f.Type, tag, tagKey, tagVal)
+ }
+ if tag := f.Tag.Get("protobuf_oneof"); tag != "" {
+ n := len(md.L2.Oneofs.List)
+ md.L2.Oneofs.List = append(md.L2.Oneofs.List, filedesc.Oneof{})
+ od := &md.L2.Oneofs.List[n]
+ od.L0.FullName = md.FullName().Append(pref.Name(tag))
+ od.L0.ParentFile = md.L0.ParentFile
+ od.L0.Parent = md
+ od.L0.Index = n
+
+ for _, t := range oneofWrappers {
+ if t.Implements(f.Type) {
+ f := t.Elem().Field(0)
+ if tag := f.Tag.Get("protobuf"); tag != "" {
+ aberrantAppendField(md, f.Type, tag, "", "")
+ fd := &md.L2.Fields.List[len(md.L2.Fields.List)-1]
+ fd.L1.ContainingOneof = od
+ od.L1.Fields.List = append(od.L1.Fields.List, fd)
+ }
+ }
+ }
+ }
+ }
+
+ return md
+}
+
+func aberrantDeriveMessageName(t reflect.Type, name pref.FullName) pref.FullName {
+ if name.IsValid() {
+ return name
+ }
+ func() {
+ defer func() { recover() }() // swallow possible nil panics
+ if m, ok := reflect.Zero(t).Interface().(interface{ XXX_MessageName() string }); ok {
+ name = pref.FullName(m.XXX_MessageName())
+ }
+ }()
+ if name.IsValid() {
+ return name
+ }
+ if t.Kind() == reflect.Ptr {
+ t = t.Elem()
+ }
+ return AberrantDeriveFullName(t)
+}
+
+func aberrantAppendField(md *filedesc.Message, goType reflect.Type, tag, tagKey, tagVal string) {
+ t := goType
+ isOptional := t.Kind() == reflect.Ptr && t.Elem().Kind() != reflect.Struct
+ isRepeated := t.Kind() == reflect.Slice && t.Elem().Kind() != reflect.Uint8
+ if isOptional || isRepeated {
+ t = t.Elem()
+ }
+ fd := ptag.Unmarshal(tag, t, placeholderEnumValues{}).(*filedesc.Field)
+
+ // Append field descriptor to the message.
+ n := len(md.L2.Fields.List)
+ md.L2.Fields.List = append(md.L2.Fields.List, *fd)
+ fd = &md.L2.Fields.List[n]
+ fd.L0.FullName = md.FullName().Append(fd.Name())
+ fd.L0.ParentFile = md.L0.ParentFile
+ fd.L0.Parent = md
+ fd.L0.Index = n
+
+ if fd.L1.IsWeak || fd.L1.HasPacked {
+ fd.L1.Options = func() pref.ProtoMessage {
+ opts := descopts.Field.ProtoReflect().New()
+ if fd.L1.IsWeak {
+ opts.Set(opts.Descriptor().Fields().ByName("weak"), protoreflect.ValueOfBool(true))
+ }
+ if fd.L1.HasPacked {
+ opts.Set(opts.Descriptor().Fields().ByName("packed"), protoreflect.ValueOfBool(fd.L1.IsPacked))
+ }
+ return opts.Interface()
+ }
+ }
+
+ // Populate Enum and Message.
+ if fd.Enum() == nil && fd.Kind() == pref.EnumKind {
+ switch v := reflect.Zero(t).Interface().(type) {
+ case pref.Enum:
+ fd.L1.Enum = v.Descriptor()
+ default:
+ fd.L1.Enum = LegacyLoadEnumDesc(t)
+ }
+ }
+ if fd.Message() == nil && (fd.Kind() == pref.MessageKind || fd.Kind() == pref.GroupKind) {
+ switch v := reflect.Zero(t).Interface().(type) {
+ case pref.ProtoMessage:
+ fd.L1.Message = v.ProtoReflect().Descriptor()
+ case messageV1:
+ fd.L1.Message = LegacyLoadMessageDesc(t)
+ default:
+ if t.Kind() == reflect.Map {
+ n := len(md.L1.Messages.List)
+ md.L1.Messages.List = append(md.L1.Messages.List, filedesc.Message{L2: new(filedesc.MessageL2)})
+ md2 := &md.L1.Messages.List[n]
+ md2.L0.FullName = md.FullName().Append(pref.Name(strs.MapEntryName(string(fd.Name()))))
+ md2.L0.ParentFile = md.L0.ParentFile
+ md2.L0.Parent = md
+ md2.L0.Index = n
+
+ md2.L1.IsMapEntry = true
+ md2.L2.Options = func() pref.ProtoMessage {
+ opts := descopts.Message.ProtoReflect().New()
+ opts.Set(opts.Descriptor().Fields().ByName("map_entry"), protoreflect.ValueOfBool(true))
+ return opts.Interface()
+ }
+
+ aberrantAppendField(md2, t.Key(), tagKey, "", "")
+ aberrantAppendField(md2, t.Elem(), tagVal, "", "")
+
+ fd.L1.Message = md2
+ break
+ }
+ fd.L1.Message = aberrantLoadMessageDescReentrant(t, "")
+ }
+ }
+}
+
+type placeholderEnumValues struct {
+ protoreflect.EnumValueDescriptors
+}
+
+func (placeholderEnumValues) ByNumber(n pref.EnumNumber) pref.EnumValueDescriptor {
+ return filedesc.PlaceholderEnumValue(pref.FullName(fmt.Sprintf("UNKNOWN_%d", n)))
+}
+
+// legacyMarshaler is the proto.Marshaler interface superseded by protoiface.Methoder.
+type legacyMarshaler interface {
+ Marshal() ([]byte, error)
+}
+
+// legacyUnmarshaler is the proto.Unmarshaler interface superseded by protoiface.Methoder.
+type legacyUnmarshaler interface {
+ Unmarshal([]byte) error
+}
+
+// legacyMerger is the proto.Merger interface superseded by protoiface.Methoder.
+type legacyMerger interface {
+ Merge(protoiface.MessageV1)
+}
+
+var aberrantProtoMethods = &piface.Methods{
+ Marshal: legacyMarshal,
+ Unmarshal: legacyUnmarshal,
+ Merge: legacyMerge,
+
+ // We have no way to tell whether the type's Marshal method
+ // supports deterministic serialization or not, but this
+ // preserves the v1 implementation's behavior of always
+ // calling Marshal methods when present.
+ Flags: piface.SupportMarshalDeterministic,
+}
+
+func legacyMarshal(in piface.MarshalInput) (piface.MarshalOutput, error) {
+ v := in.Message.(unwrapper).protoUnwrap()
+ marshaler, ok := v.(legacyMarshaler)
+ if !ok {
+ return piface.MarshalOutput{}, errors.New("%T does not implement Marshal", v)
+ }
+ out, err := marshaler.Marshal()
+ if in.Buf != nil {
+ out = append(in.Buf, out...)
+ }
+ return piface.MarshalOutput{
+ Buf: out,
+ }, err
+}
+
+func legacyUnmarshal(in piface.UnmarshalInput) (piface.UnmarshalOutput, error) {
+ v := in.Message.(unwrapper).protoUnwrap()
+ unmarshaler, ok := v.(legacyUnmarshaler)
+ if !ok {
+ return piface.UnmarshalOutput{}, errors.New("%T does not implement Unmarshal", v)
+ }
+ return piface.UnmarshalOutput{}, unmarshaler.Unmarshal(in.Buf)
+}
+
+func legacyMerge(in piface.MergeInput) piface.MergeOutput {
+ // Check whether this supports the legacy merger.
+ dstv := in.Destination.(unwrapper).protoUnwrap()
+ merger, ok := dstv.(legacyMerger)
+ if ok {
+ merger.Merge(Export{}.ProtoMessageV1Of(in.Source))
+ return piface.MergeOutput{Flags: piface.MergeComplete}
+ }
+
+ // If legacy merger is unavailable, implement merge in terms of
+ // a marshal and unmarshal operation.
+ srcv := in.Source.(unwrapper).protoUnwrap()
+ marshaler, ok := srcv.(legacyMarshaler)
+ if !ok {
+ return piface.MergeOutput{}
+ }
+ dstv = in.Destination.(unwrapper).protoUnwrap()
+ unmarshaler, ok := dstv.(legacyUnmarshaler)
+ if !ok {
+ return piface.MergeOutput{}
+ }
+ if !in.Source.IsValid() {
+ // Legacy Marshal methods may not function on nil messages.
+ // Check for a typed nil source only after we confirm that
+ // legacy Marshal/Unmarshal methods are present, for
+ // consistency.
+ return piface.MergeOutput{Flags: piface.MergeComplete}
+ }
+ b, err := marshaler.Marshal()
+ if err != nil {
+ return piface.MergeOutput{}
+ }
+ err = unmarshaler.Unmarshal(b)
+ if err != nil {
+ return piface.MergeOutput{}
+ }
+ return piface.MergeOutput{Flags: piface.MergeComplete}
+}
+
+// aberrantMessageType implements MessageType for all types other than pointer-to-struct.
+type aberrantMessageType struct {
+ t reflect.Type
+}
+
+func (mt aberrantMessageType) New() pref.Message {
+ if mt.t.Kind() == reflect.Ptr {
+ return aberrantMessage{reflect.New(mt.t.Elem())}
+ }
+ return aberrantMessage{reflect.Zero(mt.t)}
+}
+func (mt aberrantMessageType) Zero() pref.Message {
+ return aberrantMessage{reflect.Zero(mt.t)}
+}
+func (mt aberrantMessageType) GoType() reflect.Type {
+ return mt.t
+}
+func (mt aberrantMessageType) Descriptor() pref.MessageDescriptor {
+ return LegacyLoadMessageDesc(mt.t)
+}
+
+// aberrantMessage implements Message for all types other than pointer-to-struct.
+//
+// When the underlying type implements legacyMarshaler or legacyUnmarshaler,
+// the aberrant Message can be marshaled or unmarshaled. Otherwise, there is
+// not much that can be done with values of this type.
+type aberrantMessage struct {
+ v reflect.Value
+}
+
+// Reset implements the v1 proto.Message.Reset method.
+func (m aberrantMessage) Reset() {
+ if mr, ok := m.v.Interface().(interface{ Reset() }); ok {
+ mr.Reset()
+ return
+ }
+ if m.v.Kind() == reflect.Ptr && !m.v.IsNil() {
+ m.v.Elem().Set(reflect.Zero(m.v.Type().Elem()))
+ }
+}
+
+func (m aberrantMessage) ProtoReflect() pref.Message {
+ return m
+}
+
+func (m aberrantMessage) Descriptor() pref.MessageDescriptor {
+ return LegacyLoadMessageDesc(m.v.Type())
+}
+func (m aberrantMessage) Type() pref.MessageType {
+ return aberrantMessageType{m.v.Type()}
+}
+func (m aberrantMessage) New() pref.Message {
+ if m.v.Type().Kind() == reflect.Ptr {
+ return aberrantMessage{reflect.New(m.v.Type().Elem())}
+ }
+ return aberrantMessage{reflect.Zero(m.v.Type())}
+}
+func (m aberrantMessage) Interface() pref.ProtoMessage {
+ return m
+}
+func (m aberrantMessage) Range(f func(pref.FieldDescriptor, pref.Value) bool) {
+ return
+}
+func (m aberrantMessage) Has(pref.FieldDescriptor) bool {
+ return false
+}
+func (m aberrantMessage) Clear(pref.FieldDescriptor) {
+ panic("invalid Message.Clear on " + string(m.Descriptor().FullName()))
+}
+func (m aberrantMessage) Get(fd pref.FieldDescriptor) pref.Value {
+ if fd.Default().IsValid() {
+ return fd.Default()
+ }
+ panic("invalid Message.Get on " + string(m.Descriptor().FullName()))
+}
+func (m aberrantMessage) Set(pref.FieldDescriptor, pref.Value) {
+ panic("invalid Message.Set on " + string(m.Descriptor().FullName()))
+}
+func (m aberrantMessage) Mutable(pref.FieldDescriptor) pref.Value {
+ panic("invalid Message.Mutable on " + string(m.Descriptor().FullName()))
+}
+func (m aberrantMessage) NewField(pref.FieldDescriptor) pref.Value {
+ panic("invalid Message.NewField on " + string(m.Descriptor().FullName()))
+}
+func (m aberrantMessage) WhichOneof(pref.OneofDescriptor) pref.FieldDescriptor {
+ panic("invalid Message.WhichOneof descriptor on " + string(m.Descriptor().FullName()))
+}
+func (m aberrantMessage) GetUnknown() pref.RawFields {
+ return nil
+}
+func (m aberrantMessage) SetUnknown(pref.RawFields) {
+ // SetUnknown discards its input on messages which don't support unknown field storage.
+}
+func (m aberrantMessage) IsValid() bool {
+ if m.v.Kind() == reflect.Ptr {
+ return !m.v.IsNil()
+ }
+ return false
+}
+func (m aberrantMessage) ProtoMethods() *piface.Methods {
+ return aberrantProtoMethods
+}
+func (m aberrantMessage) protoUnwrap() interface{} {
+ return m.v.Interface()
+}
generated by cgit v1.2.3 (git 2.25.1) at 2024-06-03 04:07:55 +0000