1// Copyright 2018 The Go Authors. All rights reserved.
2// Use of this source code is governed by a BSD-style
3// license that can be found in the LICENSE file.
4
5package impl
6
7import (
8 "fmt"
9 "reflect"
10 "strconv"
11
12 "google.golang.org/protobuf/encoding/prototext"
13 "google.golang.org/protobuf/internal/errors"
14 "google.golang.org/protobuf/proto"
15 "google.golang.org/protobuf/reflect/protoreflect"
16 "google.golang.org/protobuf/runtime/protoiface"
17)
18
19// Export is a zero-length named type that exists only to export a set of
20// functions that we do not want to appear in godoc.
21type Export struct{}
22
23// NewError formats a string according to the format specifier and arguments and
24// returns an error that has a "proto" prefix.
25func (Export) NewError(f string, x ...any) error {
26 return errors.New(f, x...)
27}
28
29// enum is any enum type generated by protoc-gen-go
30// and must be a named int32 type.
31type enum = any
32
33// EnumOf returns the protoreflect.Enum interface over e.
34// It returns nil if e is nil.
35func (Export) EnumOf(e enum) protoreflect.Enum {
36 switch e := e.(type) {
37 case nil:
38 return nil
39 case protoreflect.Enum:
40 return e
41 default:
42 return legacyWrapEnum(reflect.ValueOf(e))
43 }
44}
45
46// EnumDescriptorOf returns the protoreflect.EnumDescriptor for e.
47// It returns nil if e is nil.
48func (Export) EnumDescriptorOf(e enum) protoreflect.EnumDescriptor {
49 switch e := e.(type) {
50 case nil:
51 return nil
52 case protoreflect.Enum:
53 return e.Descriptor()
54 default:
55 return LegacyLoadEnumDesc(reflect.TypeOf(e))
56 }
57}
58
59// EnumTypeOf returns the protoreflect.EnumType for e.
60// It returns nil if e is nil.
61func (Export) EnumTypeOf(e enum) protoreflect.EnumType {
62 switch e := e.(type) {
63 case nil:
64 return nil
65 case protoreflect.Enum:
66 return e.Type()
67 default:
68 return legacyLoadEnumType(reflect.TypeOf(e))
69 }
70}
71
72// EnumStringOf returns the enum value as a string, either as the name if
73// the number is resolvable, or the number formatted as a string.
74func (Export) EnumStringOf(ed protoreflect.EnumDescriptor, n protoreflect.EnumNumber) string {
75 ev := ed.Values().ByNumber(n)
76 if ev != nil {
77 return string(ev.Name())
78 }
79 return strconv.Itoa(int(n))
80}
81
82// message is any message type generated by protoc-gen-go
83// and must be a pointer to a named struct type.
84type message = any
85
86// legacyMessageWrapper wraps a v2 message as a v1 message.
87type legacyMessageWrapper struct{ m protoreflect.ProtoMessage }
88
89func (m legacyMessageWrapper) Reset() { proto.Reset(m.m) }
90func (m legacyMessageWrapper) String() string { return Export{}.MessageStringOf(m.m) }
91func (m legacyMessageWrapper) ProtoMessage() {}
92
93// ProtoMessageV1Of converts either a v1 or v2 message to a v1 message.
94// It returns nil if m is nil.
95func (Export) ProtoMessageV1Of(m message) protoiface.MessageV1 {
96 switch mv := m.(type) {
97 case nil:
98 return nil
99 case protoiface.MessageV1:
100 return mv
101 case unwrapper:
102 return Export{}.ProtoMessageV1Of(mv.protoUnwrap())
103 case protoreflect.ProtoMessage:
104 return legacyMessageWrapper{mv}
105 default:
106 panic(fmt.Sprintf("message %T is neither a v1 or v2 Message", m))
107 }
108}
109
110func (Export) protoMessageV2Of(m message) protoreflect.ProtoMessage {
111 switch mv := m.(type) {
112 case nil:
113 return nil
114 case protoreflect.ProtoMessage:
115 return mv
116 case legacyMessageWrapper:
117 return mv.m
118 case protoiface.MessageV1:
119 return nil
120 default:
121 panic(fmt.Sprintf("message %T is neither a v1 or v2 Message", m))
122 }
123}
124
125// ProtoMessageV2Of converts either a v1 or v2 message to a v2 message.
126// It returns nil if m is nil.
127func (Export) ProtoMessageV2Of(m message) protoreflect.ProtoMessage {
128 if m == nil {
129 return nil
130 }
131 if mv := (Export{}).protoMessageV2Of(m); mv != nil {
132 return mv
133 }
134 return legacyWrapMessage(reflect.ValueOf(m)).Interface()
135}
136
137// MessageOf returns the protoreflect.Message interface over m.
138// It returns nil if m is nil.
139func (Export) MessageOf(m message) protoreflect.Message {
140 if m == nil {
141 return nil
142 }
143 if mv := (Export{}).protoMessageV2Of(m); mv != nil {
144 return mv.ProtoReflect()
145 }
146 return legacyWrapMessage(reflect.ValueOf(m))
147}
148
149// MessageDescriptorOf returns the protoreflect.MessageDescriptor for m.
150// It returns nil if m is nil.
151func (Export) MessageDescriptorOf(m message) protoreflect.MessageDescriptor {
152 if m == nil {
153 return nil
154 }
155 if mv := (Export{}).protoMessageV2Of(m); mv != nil {
156 return mv.ProtoReflect().Descriptor()
157 }
158 return LegacyLoadMessageDesc(reflect.TypeOf(m))
159}
160
161// MessageTypeOf returns the protoreflect.MessageType for m.
162// It returns nil if m is nil.
163func (Export) MessageTypeOf(m message) protoreflect.MessageType {
164 if m == nil {
165 return nil
166 }
167 if mv := (Export{}).protoMessageV2Of(m); mv != nil {
168 return mv.ProtoReflect().Type()
169 }
170 return legacyLoadMessageType(reflect.TypeOf(m), "")
171}
172
173// MessageStringOf returns the message value as a string,
174// which is the message serialized in the protobuf text format.
175func (Export) MessageStringOf(m protoreflect.ProtoMessage) string {
176 return prototext.MarshalOptions{Multiline: false}.Format(m)
177}