diff -r 4f153a23adab -r 6d9efbef00a9 vendor/google.golang.org/protobuf/internal/impl/message.go --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/vendor/google.golang.org/protobuf/internal/impl/message.go Sun Jul 11 10:35:56 2021 +0200 @@ -0,0 +1,276 @@ +// 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" + "strconv" + "strings" + "sync" + "sync/atomic" + + "google.golang.org/protobuf/internal/genid" + "google.golang.org/protobuf/reflect/protoreflect" + pref "google.golang.org/protobuf/reflect/protoreflect" + preg "google.golang.org/protobuf/reflect/protoregistry" +) + +// MessageInfo provides protobuf related functionality for a given Go type +// that represents a message. A given instance of MessageInfo is tied to +// exactly one Go type, which must be a pointer to a struct type. +// +// The exported fields must be populated before any methods are called +// and cannot be mutated after set. +type MessageInfo struct { + // GoReflectType is the underlying message Go type and must be populated. + GoReflectType reflect.Type // pointer to struct + + // Desc is the underlying message descriptor type and must be populated. + Desc pref.MessageDescriptor + + // Exporter must be provided in a purego environment in order to provide + // access to unexported fields. + Exporter exporter + + // OneofWrappers is list of pointers to oneof wrapper struct types. + OneofWrappers []interface{} + + initMu sync.Mutex // protects all unexported fields + initDone uint32 + + reflectMessageInfo // for reflection implementation + coderMessageInfo // for fast-path method implementations +} + +// exporter is a function that returns a reference to the ith field of v, +// where v is a pointer to a struct. It returns nil if it does not support +// exporting the requested field (e.g., already exported). +type exporter func(v interface{}, i int) interface{} + +// getMessageInfo returns the MessageInfo for any message type that +// is generated by our implementation of protoc-gen-go (for v2 and on). +// If it is unable to obtain a MessageInfo, it returns nil. +func getMessageInfo(mt reflect.Type) *MessageInfo { + m, ok := reflect.Zero(mt).Interface().(pref.ProtoMessage) + if !ok { + return nil + } + mr, ok := m.ProtoReflect().(interface{ ProtoMessageInfo() *MessageInfo }) + if !ok { + return nil + } + return mr.ProtoMessageInfo() +} + +func (mi *MessageInfo) init() { + // This function is called in the hot path. Inline the sync.Once logic, + // since allocating a closure for Once.Do is expensive. + // Keep init small to ensure that it can be inlined. + if atomic.LoadUint32(&mi.initDone) == 0 { + mi.initOnce() + } +} + +func (mi *MessageInfo) initOnce() { + mi.initMu.Lock() + defer mi.initMu.Unlock() + if mi.initDone == 1 { + return + } + + t := mi.GoReflectType + if t.Kind() != reflect.Ptr && t.Elem().Kind() != reflect.Struct { + panic(fmt.Sprintf("got %v, want *struct kind", t)) + } + t = t.Elem() + + si := mi.makeStructInfo(t) + mi.makeReflectFuncs(t, si) + mi.makeCoderMethods(t, si) + + atomic.StoreUint32(&mi.initDone, 1) +} + +// getPointer returns the pointer for a message, which should be of +// the type of the MessageInfo. If the message is of a different type, +// it returns ok==false. +func (mi *MessageInfo) getPointer(m pref.Message) (p pointer, ok bool) { + switch m := m.(type) { + case *messageState: + return m.pointer(), m.messageInfo() == mi + case *messageReflectWrapper: + return m.pointer(), m.messageInfo() == mi + } + return pointer{}, false +} + +type ( + SizeCache = int32 + WeakFields = map[int32]protoreflect.ProtoMessage + UnknownFields = unknownFieldsA // TODO: switch to unknownFieldsB + unknownFieldsA = []byte + unknownFieldsB = *[]byte + ExtensionFields = map[int32]ExtensionField +) + +var ( + sizecacheType = reflect.TypeOf(SizeCache(0)) + weakFieldsType = reflect.TypeOf(WeakFields(nil)) + unknownFieldsAType = reflect.TypeOf(unknownFieldsA(nil)) + unknownFieldsBType = reflect.TypeOf(unknownFieldsB(nil)) + extensionFieldsType = reflect.TypeOf(ExtensionFields(nil)) +) + +type structInfo struct { + sizecacheOffset offset + sizecacheType reflect.Type + weakOffset offset + weakType reflect.Type + unknownOffset offset + unknownType reflect.Type + extensionOffset offset + extensionType reflect.Type + + fieldsByNumber map[pref.FieldNumber]reflect.StructField + oneofsByName map[pref.Name]reflect.StructField + oneofWrappersByType map[reflect.Type]pref.FieldNumber + oneofWrappersByNumber map[pref.FieldNumber]reflect.Type +} + +func (mi *MessageInfo) makeStructInfo(t reflect.Type) structInfo { + si := structInfo{ + sizecacheOffset: invalidOffset, + weakOffset: invalidOffset, + unknownOffset: invalidOffset, + extensionOffset: invalidOffset, + + fieldsByNumber: map[pref.FieldNumber]reflect.StructField{}, + oneofsByName: map[pref.Name]reflect.StructField{}, + oneofWrappersByType: map[reflect.Type]pref.FieldNumber{}, + oneofWrappersByNumber: map[pref.FieldNumber]reflect.Type{}, + } + +fieldLoop: + for i := 0; i < t.NumField(); i++ { + switch f := t.Field(i); f.Name { + case genid.SizeCache_goname, genid.SizeCacheA_goname: + if f.Type == sizecacheType { + si.sizecacheOffset = offsetOf(f, mi.Exporter) + si.sizecacheType = f.Type + } + case genid.WeakFields_goname, genid.WeakFieldsA_goname: + if f.Type == weakFieldsType { + si.weakOffset = offsetOf(f, mi.Exporter) + si.weakType = f.Type + } + case genid.UnknownFields_goname, genid.UnknownFieldsA_goname: + if f.Type == unknownFieldsAType || f.Type == unknownFieldsBType { + si.unknownOffset = offsetOf(f, mi.Exporter) + si.unknownType = f.Type + } + case genid.ExtensionFields_goname, genid.ExtensionFieldsA_goname, genid.ExtensionFieldsB_goname: + if f.Type == extensionFieldsType { + si.extensionOffset = offsetOf(f, mi.Exporter) + si.extensionType = f.Type + } + default: + for _, s := range strings.Split(f.Tag.Get("protobuf"), ",") { + if len(s) > 0 && strings.Trim(s, "0123456789") == "" { + n, _ := strconv.ParseUint(s, 10, 64) + si.fieldsByNumber[pref.FieldNumber(n)] = f + continue fieldLoop + } + } + if s := f.Tag.Get("protobuf_oneof"); len(s) > 0 { + si.oneofsByName[pref.Name(s)] = f + continue fieldLoop + } + } + } + + // Derive a mapping of oneof wrappers to fields. + oneofWrappers := mi.OneofWrappers + for _, method := range []string{"XXX_OneofFuncs", "XXX_OneofWrappers"} { + if fn, ok := reflect.PtrTo(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 { + oneofWrappers = vs + } + } + } + } + for _, v := range oneofWrappers { + tf := reflect.TypeOf(v).Elem() + f := tf.Field(0) + for _, s := range strings.Split(f.Tag.Get("protobuf"), ",") { + if len(s) > 0 && strings.Trim(s, "0123456789") == "" { + n, _ := strconv.ParseUint(s, 10, 64) + si.oneofWrappersByType[tf] = pref.FieldNumber(n) + si.oneofWrappersByNumber[pref.FieldNumber(n)] = tf + break + } + } + } + + return si +} + +func (mi *MessageInfo) New() protoreflect.Message { + return mi.MessageOf(reflect.New(mi.GoReflectType.Elem()).Interface()) +} +func (mi *MessageInfo) Zero() protoreflect.Message { + return mi.MessageOf(reflect.Zero(mi.GoReflectType).Interface()) +} +func (mi *MessageInfo) Descriptor() protoreflect.MessageDescriptor { + return mi.Desc +} +func (mi *MessageInfo) Enum(i int) protoreflect.EnumType { + mi.init() + fd := mi.Desc.Fields().Get(i) + return Export{}.EnumTypeOf(mi.fieldTypes[fd.Number()]) +} +func (mi *MessageInfo) Message(i int) protoreflect.MessageType { + mi.init() + fd := mi.Desc.Fields().Get(i) + switch { + case fd.IsWeak(): + mt, _ := preg.GlobalTypes.FindMessageByName(fd.Message().FullName()) + return mt + case fd.IsMap(): + return mapEntryType{fd.Message(), mi.fieldTypes[fd.Number()]} + default: + return Export{}.MessageTypeOf(mi.fieldTypes[fd.Number()]) + } +} + +type mapEntryType struct { + desc protoreflect.MessageDescriptor + valType interface{} // zero value of enum or message type +} + +func (mt mapEntryType) New() protoreflect.Message { + return nil +} +func (mt mapEntryType) Zero() protoreflect.Message { + return nil +} +func (mt mapEntryType) Descriptor() protoreflect.MessageDescriptor { + return mt.desc +} +func (mt mapEntryType) Enum(i int) protoreflect.EnumType { + fd := mt.desc.Fields().Get(i) + if fd.Enum() == nil { + return nil + } + return Export{}.EnumTypeOf(mt.valType) +} +func (mt mapEntryType) Message(i int) protoreflect.MessageType { + fd := mt.desc.Fields().Get(i) + if fd.Message() == nil { + return nil + } + return Export{}.MessageTypeOf(mt.valType) +}