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