| // 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/filedesc" |
| "google.golang.org/protobuf/internal/strs" |
| "google.golang.org/protobuf/reflect/protoreflect" |
| ) |
| |
| // legacyEnumName returns the name of enums used in legacy code. |
| // It is neither the protobuf full name nor the qualified Go name, |
| // but rather an odd hybrid of both. |
| func legacyEnumName(ed protoreflect.EnumDescriptor) string { |
| var protoPkg string |
| enumName := string(ed.FullName()) |
| if fd := ed.ParentFile(); fd != nil { |
| protoPkg = string(fd.Package()) |
| enumName = strings.TrimPrefix(enumName, protoPkg+".") |
| } |
| if protoPkg == "" { |
| return strs.GoCamelCase(enumName) |
| } |
| return protoPkg + "." + strs.GoCamelCase(enumName) |
| } |
| |
| // legacyWrapEnum wraps v as a protoreflect.Enum, |
| // where v must be a int32 kind and not implement the v2 API already. |
| func legacyWrapEnum(v reflect.Value) protoreflect.Enum { |
| et := legacyLoadEnumType(v.Type()) |
| return et.New(protoreflect.EnumNumber(v.Int())) |
| } |
| |
| var legacyEnumTypeCache sync.Map // map[reflect.Type]protoreflect.EnumType |
| |
| // legacyLoadEnumType dynamically loads a protoreflect.EnumType for t, |
| // where t must be an int32 kind and not implement the v2 API already. |
| func legacyLoadEnumType(t reflect.Type) protoreflect.EnumType { |
| // Fast-path: check if a EnumType is cached for this concrete type. |
| if et, ok := legacyEnumTypeCache.Load(t); ok { |
| return et.(protoreflect.EnumType) |
| } |
| |
| // Slow-path: derive enum descriptor and initialize EnumType. |
| var et protoreflect.EnumType |
| ed := LegacyLoadEnumDesc(t) |
| et = &legacyEnumType{ |
| desc: ed, |
| goType: t, |
| } |
| if et, ok := legacyEnumTypeCache.LoadOrStore(t, et); ok { |
| return et.(protoreflect.EnumType) |
| } |
| return et |
| } |
| |
| type legacyEnumType struct { |
| desc protoreflect.EnumDescriptor |
| goType reflect.Type |
| m sync.Map // map[protoreflect.EnumNumber]proto.Enum |
| } |
| |
| func (t *legacyEnumType) New(n protoreflect.EnumNumber) protoreflect.Enum { |
| if e, ok := t.m.Load(n); ok { |
| return e.(protoreflect.Enum) |
| } |
| e := &legacyEnumWrapper{num: n, pbTyp: t, goTyp: t.goType} |
| t.m.Store(n, e) |
| return e |
| } |
| func (t *legacyEnumType) Descriptor() protoreflect.EnumDescriptor { |
| return t.desc |
| } |
| |
| type legacyEnumWrapper struct { |
| num protoreflect.EnumNumber |
| pbTyp protoreflect.EnumType |
| goTyp reflect.Type |
| } |
| |
| func (e *legacyEnumWrapper) Descriptor() protoreflect.EnumDescriptor { |
| return e.pbTyp.Descriptor() |
| } |
| func (e *legacyEnumWrapper) Type() protoreflect.EnumType { |
| return e.pbTyp |
| } |
| func (e *legacyEnumWrapper) Number() protoreflect.EnumNumber { |
| return e.num |
| } |
| func (e *legacyEnumWrapper) ProtoReflect() protoreflect.Enum { |
| return e |
| } |
| func (e *legacyEnumWrapper) protoUnwrap() interface{} { |
| v := reflect.New(e.goTyp).Elem() |
| v.SetInt(int64(e.num)) |
| return v.Interface() |
| } |
| |
| var ( |
| _ protoreflect.Enum = (*legacyEnumWrapper)(nil) |
| _ unwrapper = (*legacyEnumWrapper)(nil) |
| ) |
| |
| var legacyEnumDescCache sync.Map // map[reflect.Type]protoreflect.EnumDescriptor |
| |
| // LegacyLoadEnumDesc returns an EnumDescriptor derived from the Go type, |
| // which must be an int32 kind and not implement the v2 API already. |
| // |
| // This is exported for testing purposes. |
| func LegacyLoadEnumDesc(t reflect.Type) protoreflect.EnumDescriptor { |
| // Fast-path: check if an EnumDescriptor is cached for this concrete type. |
| if ed, ok := legacyEnumDescCache.Load(t); ok { |
| return ed.(protoreflect.EnumDescriptor) |
| } |
| |
| // Slow-path: initialize EnumDescriptor from the raw descriptor. |
| ev := reflect.Zero(t).Interface() |
| if _, ok := ev.(protoreflect.Enum); ok { |
| panic(fmt.Sprintf("%v already implements proto.Enum", t)) |
| } |
| edV1, ok := ev.(enumV1) |
| if !ok { |
| return aberrantLoadEnumDesc(t) |
| } |
| b, idxs := edV1.EnumDescriptor() |
| |
| var ed protoreflect.EnumDescriptor |
| if len(idxs) == 1 { |
| ed = legacyLoadFileDesc(b).Enums().Get(idxs[0]) |
| } else { |
| md := legacyLoadFileDesc(b).Messages().Get(idxs[0]) |
| for _, i := range idxs[1 : len(idxs)-1] { |
| md = md.Messages().Get(i) |
| } |
| ed = md.Enums().Get(idxs[len(idxs)-1]) |
| } |
| if ed, ok := legacyEnumDescCache.LoadOrStore(t, ed); ok { |
| return ed.(protoreflect.EnumDescriptor) |
| } |
| return ed |
| } |
| |
| var aberrantEnumDescCache sync.Map // map[reflect.Type]protoreflect.EnumDescriptor |
| |
| // aberrantLoadEnumDesc returns an EnumDescriptor derived from the Go type, |
| // which must not implement protoreflect.Enum or enumV1. |
| // |
| // If the type does not implement enumV1, then there is no reliable |
| // way to derive the original protobuf type information. |
| // We are unable to use the global enum registry since it is |
| // unfortunately keyed by the protobuf full name, which we also do not know. |
| // Thus, this produces some bogus enum descriptor based on the Go type name. |
| func aberrantLoadEnumDesc(t reflect.Type) protoreflect.EnumDescriptor { |
| // Fast-path: check if an EnumDescriptor is cached for this concrete type. |
| if ed, ok := aberrantEnumDescCache.Load(t); ok { |
| return ed.(protoreflect.EnumDescriptor) |
| } |
| |
| // Slow-path: construct a bogus, but unique EnumDescriptor. |
| ed := &filedesc.Enum{L2: new(filedesc.EnumL2)} |
| ed.L0.FullName = AberrantDeriveFullName(t) // e.g., github_com.user.repo.MyEnum |
| ed.L0.ParentFile = filedesc.SurrogateProto3 |
| ed.L2.Values.List = append(ed.L2.Values.List, filedesc.EnumValue{}) |
| |
| // TODO: Use the presence of a UnmarshalJSON method to determine proto2? |
| |
| vd := &ed.L2.Values.List[0] |
| vd.L0.FullName = ed.L0.FullName + "_UNKNOWN" // e.g., github_com.user.repo.MyEnum_UNKNOWN |
| vd.L0.ParentFile = ed.L0.ParentFile |
| vd.L0.Parent = ed |
| |
| // TODO: We could use the String method to obtain some enum value names by |
| // starting at 0 and print the enum until it produces invalid identifiers. |
| // An exhaustive query is clearly impractical, but can be best-effort. |
| |
| if ed, ok := aberrantEnumDescCache.LoadOrStore(t, ed); ok { |
| return ed.(protoreflect.EnumDescriptor) |
| } |
| return ed |
| } |
| |
| // AberrantDeriveFullName derives a fully qualified protobuf name for the given Go type |
| // The provided name is not guaranteed to be stable nor universally unique. |
| // It should be sufficiently unique within a program. |
| // |
| // This is exported for testing purposes. |
| func AberrantDeriveFullName(t reflect.Type) protoreflect.FullName { |
| sanitize := func(r rune) rune { |
| switch { |
| case r == '/': |
| return '.' |
| case 'a' <= r && r <= 'z', 'A' <= r && r <= 'Z', '0' <= r && r <= '9': |
| return r |
| default: |
| return '_' |
| } |
| } |
| prefix := strings.Map(sanitize, t.PkgPath()) |
| suffix := strings.Map(sanitize, t.Name()) |
| if suffix == "" { |
| suffix = fmt.Sprintf("UnknownX%X", reflect.ValueOf(t).Pointer()) |
| } |
| |
| ss := append(strings.Split(prefix, "."), suffix) |
| for i, s := range ss { |
| if s == "" || ('0' <= s[0] && s[0] <= '9') { |
| ss[i] = "x" + s |
| } |
| } |
| return protoreflect.FullName(strings.Join(ss, ".")) |
| } |