podman

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// Copyright 2018 The Go Authors. All rights reserved.
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// Use of this source code is governed by a BSD-style
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// license that can be found in the LICENSE file.
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package impl
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import (
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	"fmt"
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	"reflect"
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	"strings"
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	"sync"
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	"google.golang.org/protobuf/internal/filedesc"
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	"google.golang.org/protobuf/internal/strs"
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	"google.golang.org/protobuf/reflect/protoreflect"
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)
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// legacyEnumName returns the name of enums used in legacy code.
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// It is neither the protobuf full name nor the qualified Go name,
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// but rather an odd hybrid of both.
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func legacyEnumName(ed protoreflect.EnumDescriptor) string {
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	var protoPkg string
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	enumName := string(ed.FullName())
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	if fd := ed.ParentFile(); fd != nil {
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		protoPkg = string(fd.Package())
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		enumName = strings.TrimPrefix(enumName, protoPkg+".")
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	}
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	if protoPkg == "" {
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		return strs.GoCamelCase(enumName)
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	}
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	return protoPkg + "." + strs.GoCamelCase(enumName)
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}
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// legacyWrapEnum wraps v as a protoreflect.Enum,
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// where v must be a int32 kind and not implement the v2 API already.
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func legacyWrapEnum(v reflect.Value) protoreflect.Enum {
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	et := legacyLoadEnumType(v.Type())
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	return et.New(protoreflect.EnumNumber(v.Int()))
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}
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var legacyEnumTypeCache sync.Map // map[reflect.Type]protoreflect.EnumType
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// legacyLoadEnumType dynamically loads a protoreflect.EnumType for t,
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// where t must be an int32 kind and not implement the v2 API already.
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func legacyLoadEnumType(t reflect.Type) protoreflect.EnumType {
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	// Fast-path: check if a EnumType is cached for this concrete type.
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	if et, ok := legacyEnumTypeCache.Load(t); ok {
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		return et.(protoreflect.EnumType)
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	}
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	// Slow-path: derive enum descriptor and initialize EnumType.
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	var et protoreflect.EnumType
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	ed := LegacyLoadEnumDesc(t)
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	et = &legacyEnumType{
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		desc:   ed,
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		goType: t,
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	}
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	if et, ok := legacyEnumTypeCache.LoadOrStore(t, et); ok {
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		return et.(protoreflect.EnumType)
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	}
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	return et
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}
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type legacyEnumType struct {
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	desc   protoreflect.EnumDescriptor
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	goType reflect.Type
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	m      sync.Map // map[protoreflect.EnumNumber]proto.Enum
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}
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func (t *legacyEnumType) New(n protoreflect.EnumNumber) protoreflect.Enum {
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	if e, ok := t.m.Load(n); ok {
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		return e.(protoreflect.Enum)
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	}
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	e := &legacyEnumWrapper{num: n, pbTyp: t, goTyp: t.goType}
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	t.m.Store(n, e)
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	return e
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}
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func (t *legacyEnumType) Descriptor() protoreflect.EnumDescriptor {
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	return t.desc
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}
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type legacyEnumWrapper struct {
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	num   protoreflect.EnumNumber
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	pbTyp protoreflect.EnumType
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	goTyp reflect.Type
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}
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func (e *legacyEnumWrapper) Descriptor() protoreflect.EnumDescriptor {
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	return e.pbTyp.Descriptor()
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}
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func (e *legacyEnumWrapper) Type() protoreflect.EnumType {
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	return e.pbTyp
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}
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func (e *legacyEnumWrapper) Number() protoreflect.EnumNumber {
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	return e.num
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}
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func (e *legacyEnumWrapper) ProtoReflect() protoreflect.Enum {
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	return e
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}
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func (e *legacyEnumWrapper) protoUnwrap() interface{} {
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	v := reflect.New(e.goTyp).Elem()
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	v.SetInt(int64(e.num))
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	return v.Interface()
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}
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var (
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	_ protoreflect.Enum = (*legacyEnumWrapper)(nil)
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	_ unwrapper         = (*legacyEnumWrapper)(nil)
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)
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var legacyEnumDescCache sync.Map // map[reflect.Type]protoreflect.EnumDescriptor
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// LegacyLoadEnumDesc returns an EnumDescriptor derived from the Go type,
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// which must be an int32 kind and not implement the v2 API already.
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//
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// This is exported for testing purposes.
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func LegacyLoadEnumDesc(t reflect.Type) protoreflect.EnumDescriptor {
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	// Fast-path: check if an EnumDescriptor is cached for this concrete type.
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	if ed, ok := legacyEnumDescCache.Load(t); ok {
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		return ed.(protoreflect.EnumDescriptor)
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	}
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	// Slow-path: initialize EnumDescriptor from the raw descriptor.
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	ev := reflect.Zero(t).Interface()
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	if _, ok := ev.(protoreflect.Enum); ok {
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		panic(fmt.Sprintf("%v already implements proto.Enum", t))
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	}
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	edV1, ok := ev.(enumV1)
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	if !ok {
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		return aberrantLoadEnumDesc(t)
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	}
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	b, idxs := edV1.EnumDescriptor()
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	var ed protoreflect.EnumDescriptor
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	if len(idxs) == 1 {
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		ed = legacyLoadFileDesc(b).Enums().Get(idxs[0])
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	} else {
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		md := legacyLoadFileDesc(b).Messages().Get(idxs[0])
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		for _, i := range idxs[1 : len(idxs)-1] {
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			md = md.Messages().Get(i)
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		}
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		ed = md.Enums().Get(idxs[len(idxs)-1])
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	}
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	if ed, ok := legacyEnumDescCache.LoadOrStore(t, ed); ok {
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		return ed.(protoreflect.EnumDescriptor)
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	}
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	return ed
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}
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var aberrantEnumDescCache sync.Map // map[reflect.Type]protoreflect.EnumDescriptor
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// aberrantLoadEnumDesc returns an EnumDescriptor derived from the Go type,
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// which must not implement protoreflect.Enum or enumV1.
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//
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// If the type does not implement enumV1, then there is no reliable
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// way to derive the original protobuf type information.
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// We are unable to use the global enum registry since it is
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// unfortunately keyed by the protobuf full name, which we also do not know.
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// Thus, this produces some bogus enum descriptor based on the Go type name.
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func aberrantLoadEnumDesc(t reflect.Type) protoreflect.EnumDescriptor {
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	// Fast-path: check if an EnumDescriptor is cached for this concrete type.
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	if ed, ok := aberrantEnumDescCache.Load(t); ok {
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		return ed.(protoreflect.EnumDescriptor)
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	}
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	// Slow-path: construct a bogus, but unique EnumDescriptor.
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	ed := &filedesc.Enum{L2: new(filedesc.EnumL2)}
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	ed.L0.FullName = AberrantDeriveFullName(t) // e.g., github_com.user.repo.MyEnum
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	ed.L0.ParentFile = filedesc.SurrogateProto3
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	ed.L2.Values.List = append(ed.L2.Values.List, filedesc.EnumValue{})
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	// TODO: Use the presence of a UnmarshalJSON method to determine proto2?
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	vd := &ed.L2.Values.List[0]
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	vd.L0.FullName = ed.L0.FullName + "_UNKNOWN" // e.g., github_com.user.repo.MyEnum_UNKNOWN
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	vd.L0.ParentFile = ed.L0.ParentFile
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	vd.L0.Parent = ed
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	// TODO: We could use the String method to obtain some enum value names by
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	// starting at 0 and print the enum until it produces invalid identifiers.
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	// An exhaustive query is clearly impractical, but can be best-effort.
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	if ed, ok := aberrantEnumDescCache.LoadOrStore(t, ed); ok {
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		return ed.(protoreflect.EnumDescriptor)
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	}
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	return ed
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}
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// AberrantDeriveFullName derives a fully qualified protobuf name for the given Go type
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// The provided name is not guaranteed to be stable nor universally unique.
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// It should be sufficiently unique within a program.
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//
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// This is exported for testing purposes.
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func AberrantDeriveFullName(t reflect.Type) protoreflect.FullName {
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	sanitize := func(r rune) rune {
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		switch {
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		case r == '/':
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			return '.'
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		case 'a' <= r && r <= 'z', 'A' <= r && r <= 'Z', '0' <= r && r <= '9':
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			return r
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		default:
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			return '_'
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		}
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	}
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	prefix := strings.Map(sanitize, t.PkgPath())
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	suffix := strings.Map(sanitize, t.Name())
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	if suffix == "" {
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		suffix = fmt.Sprintf("UnknownX%X", reflect.ValueOf(t).Pointer())
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	}
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	ss := append(strings.Split(prefix, "."), suffix)
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	for i, s := range ss {
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		if s == "" || ('0' <= s[0] && s[0] <= '9') {
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			ss[i] = "x" + s
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		}
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	}
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	return protoreflect.FullName(strings.Join(ss, "."))
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}
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