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// 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"
"google.golang.org/protobuf/encoding/prototext"
"google.golang.org/protobuf/internal/errors"
"google.golang.org/protobuf/proto"
pref "google.golang.org/protobuf/reflect/protoreflect"
piface "google.golang.org/protobuf/runtime/protoiface"
)
// Export is a zero-length named type that exists only to export a set of
// functions that we do not want to appear in godoc.
type Export struct{}
// NewError formats a string according to the format specifier and arguments and
// returns an error that has a "proto" prefix.
func (Export) NewError(f string, x ...interface{}) error {
return errors.New(f, x...)
}
// enum is any enum type generated by protoc-gen-go
// and must be a named int32 type.
type enum = interface{}
// EnumOf returns the protoreflect.Enum interface over e.
// It returns nil if e is nil.
func (Export) EnumOf(e enum) pref.Enum {
switch e := e.(type) {
case nil:
return nil
case pref.Enum:
return e
default:
return legacyWrapEnum(reflect.ValueOf(e))
}
}
// EnumDescriptorOf returns the protoreflect.EnumDescriptor for e.
// It returns nil if e is nil.
func (Export) EnumDescriptorOf(e enum) pref.EnumDescriptor {
switch e := e.(type) {
case nil:
return nil
case pref.Enum:
return e.Descriptor()
default:
return LegacyLoadEnumDesc(reflect.TypeOf(e))
}
}
// EnumTypeOf returns the protoreflect.EnumType for e.
// It returns nil if e is nil.
func (Export) EnumTypeOf(e enum) pref.EnumType {
switch e := e.(type) {
case nil:
return nil
case pref.Enum:
return e.Type()
default:
return legacyLoadEnumType(reflect.TypeOf(e))
}
}
// EnumStringOf returns the enum value as a string, either as the name if
// the number is resolvable, or the number formatted as a string.
func (Export) EnumStringOf(ed pref.EnumDescriptor, n pref.EnumNumber) string {
ev := ed.Values().ByNumber(n)
if ev != nil {
return string(ev.Name())
}
return strconv.Itoa(int(n))
}
// message is any message type generated by protoc-gen-go
// and must be a pointer to a named struct type.
type message = interface{}
// legacyMessageWrapper wraps a v2 message as a v1 message.
type legacyMessageWrapper struct{ m pref.ProtoMessage }
func (m legacyMessageWrapper) Reset() { proto.Reset(m.m) }
func (m legacyMessageWrapper) String() string { return Export{}.MessageStringOf(m.m) }
func (m legacyMessageWrapper) ProtoMessage() {}
// ProtoMessageV1Of converts either a v1 or v2 message to a v1 message.
// It returns nil if m is nil.
func (Export) ProtoMessageV1Of(m message) piface.MessageV1 {
switch mv := m.(type) {
case nil:
return nil
case piface.MessageV1:
return mv
case unwrapper:
return Export{}.ProtoMessageV1Of(mv.protoUnwrap())
case pref.ProtoMessage:
return legacyMessageWrapper{mv}
default:
panic(fmt.Sprintf("message %T is neither a v1 or v2 Message", m))
}
}
func (Export) protoMessageV2Of(m message) pref.ProtoMessage {
switch mv := m.(type) {
case nil:
return nil
case pref.ProtoMessage:
return mv
case legacyMessageWrapper:
return mv.m
case piface.MessageV1:
return nil
default:
panic(fmt.Sprintf("message %T is neither a v1 or v2 Message", m))
}
}
// ProtoMessageV2Of converts either a v1 or v2 message to a v2 message.
// It returns nil if m is nil.
func (Export) ProtoMessageV2Of(m message) pref.ProtoMessage {
if m == nil {
return nil
}
if mv := (Export{}).protoMessageV2Of(m); mv != nil {
return mv
}
return legacyWrapMessage(reflect.ValueOf(m)).Interface()
}
// MessageOf returns the protoreflect.Message interface over m.
// It returns nil if m is nil.
func (Export) MessageOf(m message) pref.Message {
if m == nil {
return nil
}
if mv := (Export{}).protoMessageV2Of(m); mv != nil {
return mv.ProtoReflect()
}
return legacyWrapMessage(reflect.ValueOf(m))
}
// MessageDescriptorOf returns the protoreflect.MessageDescriptor for m.
// It returns nil if m is nil.
func (Export) MessageDescriptorOf(m message) pref.MessageDescriptor {
if m == nil {
return nil
}
if mv := (Export{}).protoMessageV2Of(m); mv != nil {
return mv.ProtoReflect().Descriptor()
}
return LegacyLoadMessageDesc(reflect.TypeOf(m))
}
// MessageTypeOf returns the protoreflect.MessageType for m.
// It returns nil if m is nil.
func (Export) MessageTypeOf(m message) pref.MessageType {
if m == nil {
return nil
}
if mv := (Export{}).protoMessageV2Of(m); mv != nil {
return mv.ProtoReflect().Type()
}
return legacyLoadMessageType(reflect.TypeOf(m), "")
}
// MessageStringOf returns the message value as a string,
// which is the message serialized in the protobuf text format.
func (Export) MessageStringOf(m pref.ProtoMessage) string {
return prototext.MarshalOptions{Multiline: false}.Format(m)
}