219 lines
6.7 KiB
Go
219 lines
6.7 KiB
Go
|
// 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, "."))
|
||
|
|
}
|