proto.go

Documentation: google.golang.org/protobuf/reflect/protodesc

     1  // Copyright 2019 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  
     5  package protodesc
     6  
     7  import (
     8  	"fmt"
     9  	"strings"
    10  
    11  	"google.golang.org/protobuf/internal/encoding/defval"
    12  	"google.golang.org/protobuf/internal/strs"
    13  	"google.golang.org/protobuf/proto"
    14  	"google.golang.org/protobuf/reflect/protoreflect"
    15  
    16  	"google.golang.org/protobuf/types/descriptorpb"
    17  )
    18  
    19  // ToFileDescriptorProto copies a [protoreflect.FileDescriptor] into a
    20  // google.protobuf.FileDescriptorProto message.
    21  func ToFileDescriptorProto(file protoreflect.FileDescriptor) *descriptorpb.FileDescriptorProto {
    22  	p := &descriptorpb.FileDescriptorProto{
    23  		Name:    proto.String(file.Path()),
    24  		Options: proto.Clone(file.Options()).(*descriptorpb.FileOptions),
    25  	}
    26  	if file.Package() != "" {
    27  		p.Package = proto.String(string(file.Package()))
    28  	}
    29  	for i, imports := 0, file.Imports(); i < imports.Len(); i++ {
    30  		imp := imports.Get(i)
    31  		p.Dependency = append(p.Dependency, imp.Path())
    32  		if imp.IsPublic {
    33  			p.PublicDependency = append(p.PublicDependency, int32(i))
    34  		}
    35  		if imp.IsWeak {
    36  			p.WeakDependency = append(p.WeakDependency, int32(i))
    37  		}
    38  	}
    39  	for i, locs := 0, file.SourceLocations(); i < locs.Len(); i++ {
    40  		loc := locs.Get(i)
    41  		l := &descriptorpb.SourceCodeInfo_Location{}
    42  		l.Path = append(l.Path, loc.Path...)
    43  		if loc.StartLine == loc.EndLine {
    44  			l.Span = []int32{int32(loc.StartLine), int32(loc.StartColumn), int32(loc.EndColumn)}
    45  		} else {
    46  			l.Span = []int32{int32(loc.StartLine), int32(loc.StartColumn), int32(loc.EndLine), int32(loc.EndColumn)}
    47  		}
    48  		l.LeadingDetachedComments = append([]string(nil), loc.LeadingDetachedComments...)
    49  		if loc.LeadingComments != "" {
    50  			l.LeadingComments = proto.String(loc.LeadingComments)
    51  		}
    52  		if loc.TrailingComments != "" {
    53  			l.TrailingComments = proto.String(loc.TrailingComments)
    54  		}
    55  		if p.SourceCodeInfo == nil {
    56  			p.SourceCodeInfo = &descriptorpb.SourceCodeInfo{}
    57  		}
    58  		p.SourceCodeInfo.Location = append(p.SourceCodeInfo.Location, l)
    59  
    60  	}
    61  	for i, messages := 0, file.Messages(); i < messages.Len(); i++ {
    62  		p.MessageType = append(p.MessageType, ToDescriptorProto(messages.Get(i)))
    63  	}
    64  	for i, enums := 0, file.Enums(); i < enums.Len(); i++ {
    65  		p.EnumType = append(p.EnumType, ToEnumDescriptorProto(enums.Get(i)))
    66  	}
    67  	for i, services := 0, file.Services(); i < services.Len(); i++ {
    68  		p.Service = append(p.Service, ToServiceDescriptorProto(services.Get(i)))
    69  	}
    70  	for i, exts := 0, file.Extensions(); i < exts.Len(); i++ {
    71  		p.Extension = append(p.Extension, ToFieldDescriptorProto(exts.Get(i)))
    72  	}
    73  	if syntax := file.Syntax(); syntax != protoreflect.Proto2 && syntax.IsValid() {
    74  		p.Syntax = proto.String(file.Syntax().String())
    75  	}
    76  	if file.Syntax() == protoreflect.Editions {
    77  		desc := file
    78  		if fileImportDesc, ok := file.(protoreflect.FileImport); ok {
    79  			desc = fileImportDesc.FileDescriptor
    80  		}
    81  
    82  		if editionsInterface, ok := desc.(interface{ Edition() int32 }); ok {
    83  			p.Edition = descriptorpb.Edition(editionsInterface.Edition()).Enum()
    84  		}
    85  	}
    86  	return p
    87  }
    88  
    89  // ToDescriptorProto copies a [protoreflect.MessageDescriptor] into a
    90  // google.protobuf.DescriptorProto message.
    91  func ToDescriptorProto(message protoreflect.MessageDescriptor) *descriptorpb.DescriptorProto {
    92  	p := &descriptorpb.DescriptorProto{
    93  		Name:    proto.String(string(message.Name())),
    94  		Options: proto.Clone(message.Options()).(*descriptorpb.MessageOptions),
    95  	}
    96  	for i, fields := 0, message.Fields(); i < fields.Len(); i++ {
    97  		p.Field = append(p.Field, ToFieldDescriptorProto(fields.Get(i)))
    98  	}
    99  	for i, exts := 0, message.Extensions(); i < exts.Len(); i++ {
   100  		p.Extension = append(p.Extension, ToFieldDescriptorProto(exts.Get(i)))
   101  	}
   102  	for i, messages := 0, message.Messages(); i < messages.Len(); i++ {
   103  		p.NestedType = append(p.NestedType, ToDescriptorProto(messages.Get(i)))
   104  	}
   105  	for i, enums := 0, message.Enums(); i < enums.Len(); i++ {
   106  		p.EnumType = append(p.EnumType, ToEnumDescriptorProto(enums.Get(i)))
   107  	}
   108  	for i, xranges := 0, message.ExtensionRanges(); i < xranges.Len(); i++ {
   109  		xrange := xranges.Get(i)
   110  		p.ExtensionRange = append(p.ExtensionRange, &descriptorpb.DescriptorProto_ExtensionRange{
   111  			Start:   proto.Int32(int32(xrange[0])),
   112  			End:     proto.Int32(int32(xrange[1])),
   113  			Options: proto.Clone(message.ExtensionRangeOptions(i)).(*descriptorpb.ExtensionRangeOptions),
   114  		})
   115  	}
   116  	for i, oneofs := 0, message.Oneofs(); i < oneofs.Len(); i++ {
   117  		p.OneofDecl = append(p.OneofDecl, ToOneofDescriptorProto(oneofs.Get(i)))
   118  	}
   119  	for i, ranges := 0, message.ReservedRanges(); i < ranges.Len(); i++ {
   120  		rrange := ranges.Get(i)
   121  		p.ReservedRange = append(p.ReservedRange, &descriptorpb.DescriptorProto_ReservedRange{
   122  			Start: proto.Int32(int32(rrange[0])),
   123  			End:   proto.Int32(int32(rrange[1])),
   124  		})
   125  	}
   126  	for i, names := 0, message.ReservedNames(); i < names.Len(); i++ {
   127  		p.ReservedName = append(p.ReservedName, string(names.Get(i)))
   128  	}
   129  	return p
   130  }
   131  
   132  // ToFieldDescriptorProto copies a [protoreflect.FieldDescriptor] into a
   133  // google.protobuf.FieldDescriptorProto message.
   134  func ToFieldDescriptorProto(field protoreflect.FieldDescriptor) *descriptorpb.FieldDescriptorProto {
   135  	p := &descriptorpb.FieldDescriptorProto{
   136  		Name:    proto.String(string(field.Name())),
   137  		Number:  proto.Int32(int32(field.Number())),
   138  		Label:   descriptorpb.FieldDescriptorProto_Label(field.Cardinality()).Enum(),
   139  		Options: proto.Clone(field.Options()).(*descriptorpb.FieldOptions),
   140  	}
   141  	if field.IsExtension() {
   142  		p.Extendee = fullNameOf(field.ContainingMessage())
   143  	}
   144  	if field.Kind().IsValid() {
   145  		p.Type = descriptorpb.FieldDescriptorProto_Type(field.Kind()).Enum()
   146  	}
   147  	if field.Enum() != nil {
   148  		p.TypeName = fullNameOf(field.Enum())
   149  	}
   150  	if field.Message() != nil {
   151  		p.TypeName = fullNameOf(field.Message())
   152  	}
   153  	if field.HasJSONName() {
   154  		// A bug in older versions of protoc would always populate the
   155  		// "json_name" option for extensions when it is meaningless.
   156  		// When it did so, it would always use the camel-cased field name.
   157  		if field.IsExtension() {
   158  			p.JsonName = proto.String(strs.JSONCamelCase(string(field.Name())))
   159  		} else {
   160  			p.JsonName = proto.String(field.JSONName())
   161  		}
   162  	}
   163  	if field.Syntax() == protoreflect.Proto3 && field.HasOptionalKeyword() {
   164  		p.Proto3Optional = proto.Bool(true)
   165  	}
   166  	if field.Syntax() == protoreflect.Editions {
   167  		// Editions have no group keyword, this type is only set so that downstream users continue
   168  		// treating this as delimited encoding.
   169  		if p.GetType() == descriptorpb.FieldDescriptorProto_TYPE_GROUP {
   170  			p.Type = descriptorpb.FieldDescriptorProto_TYPE_MESSAGE.Enum()
   171  		}
   172  		// Editions have no required keyword, this label is only set so that downstream users continue
   173  		// treating it as required.
   174  		if p.GetLabel() == descriptorpb.FieldDescriptorProto_LABEL_REQUIRED {
   175  			p.Label = descriptorpb.FieldDescriptorProto_LABEL_OPTIONAL.Enum()
   176  		}
   177  	}
   178  	if field.HasDefault() {
   179  		def, err := defval.Marshal(field.Default(), field.DefaultEnumValue(), field.Kind(), defval.Descriptor)
   180  		if err != nil && field.DefaultEnumValue() != nil {
   181  			def = string(field.DefaultEnumValue().Name()) // occurs for unresolved enum values
   182  		} else if err != nil {
   183  			panic(fmt.Sprintf("%v: %v", field.FullName(), err))
   184  		}
   185  		p.DefaultValue = proto.String(def)
   186  	}
   187  	if oneof := field.ContainingOneof(); oneof != nil {
   188  		p.OneofIndex = proto.Int32(int32(oneof.Index()))
   189  	}
   190  	return p
   191  }
   192  
   193  // ToOneofDescriptorProto copies a [protoreflect.OneofDescriptor] into a
   194  // google.protobuf.OneofDescriptorProto message.
   195  func ToOneofDescriptorProto(oneof protoreflect.OneofDescriptor) *descriptorpb.OneofDescriptorProto {
   196  	return &descriptorpb.OneofDescriptorProto{
   197  		Name:    proto.String(string(oneof.Name())),
   198  		Options: proto.Clone(oneof.Options()).(*descriptorpb.OneofOptions),
   199  	}
   200  }
   201  
   202  // ToEnumDescriptorProto copies a [protoreflect.EnumDescriptor] into a
   203  // google.protobuf.EnumDescriptorProto message.
   204  func ToEnumDescriptorProto(enum protoreflect.EnumDescriptor) *descriptorpb.EnumDescriptorProto {
   205  	p := &descriptorpb.EnumDescriptorProto{
   206  		Name:    proto.String(string(enum.Name())),
   207  		Options: proto.Clone(enum.Options()).(*descriptorpb.EnumOptions),
   208  	}
   209  	for i, values := 0, enum.Values(); i < values.Len(); i++ {
   210  		p.Value = append(p.Value, ToEnumValueDescriptorProto(values.Get(i)))
   211  	}
   212  	for i, ranges := 0, enum.ReservedRanges(); i < ranges.Len(); i++ {
   213  		rrange := ranges.Get(i)
   214  		p.ReservedRange = append(p.ReservedRange, &descriptorpb.EnumDescriptorProto_EnumReservedRange{
   215  			Start: proto.Int32(int32(rrange[0])),
   216  			End:   proto.Int32(int32(rrange[1])),
   217  		})
   218  	}
   219  	for i, names := 0, enum.ReservedNames(); i < names.Len(); i++ {
   220  		p.ReservedName = append(p.ReservedName, string(names.Get(i)))
   221  	}
   222  	return p
   223  }
   224  
   225  // ToEnumValueDescriptorProto copies a [protoreflect.EnumValueDescriptor] into a
   226  // google.protobuf.EnumValueDescriptorProto message.
   227  func ToEnumValueDescriptorProto(value protoreflect.EnumValueDescriptor) *descriptorpb.EnumValueDescriptorProto {
   228  	return &descriptorpb.EnumValueDescriptorProto{
   229  		Name:    proto.String(string(value.Name())),
   230  		Number:  proto.Int32(int32(value.Number())),
   231  		Options: proto.Clone(value.Options()).(*descriptorpb.EnumValueOptions),
   232  	}
   233  }
   234  
   235  // ToServiceDescriptorProto copies a [protoreflect.ServiceDescriptor] into a
   236  // google.protobuf.ServiceDescriptorProto message.
   237  func ToServiceDescriptorProto(service protoreflect.ServiceDescriptor) *descriptorpb.ServiceDescriptorProto {
   238  	p := &descriptorpb.ServiceDescriptorProto{
   239  		Name:    proto.String(string(service.Name())),
   240  		Options: proto.Clone(service.Options()).(*descriptorpb.ServiceOptions),
   241  	}
   242  	for i, methods := 0, service.Methods(); i < methods.Len(); i++ {
   243  		p.Method = append(p.Method, ToMethodDescriptorProto(methods.Get(i)))
   244  	}
   245  	return p
   246  }
   247  
   248  // ToMethodDescriptorProto copies a [protoreflect.MethodDescriptor] into a
   249  // google.protobuf.MethodDescriptorProto message.
   250  func ToMethodDescriptorProto(method protoreflect.MethodDescriptor) *descriptorpb.MethodDescriptorProto {
   251  	p := &descriptorpb.MethodDescriptorProto{
   252  		Name:       proto.String(string(method.Name())),
   253  		InputType:  fullNameOf(method.Input()),
   254  		OutputType: fullNameOf(method.Output()),
   255  		Options:    proto.Clone(method.Options()).(*descriptorpb.MethodOptions),
   256  	}
   257  	if method.IsStreamingClient() {
   258  		p.ClientStreaming = proto.Bool(true)
   259  	}
   260  	if method.IsStreamingServer() {
   261  		p.ServerStreaming = proto.Bool(true)
   262  	}
   263  	return p
   264  }
   265  
   266  func fullNameOf(d protoreflect.Descriptor) *string {
   267  	if d == nil {
   268  		return nil
   269  	}
   270  	if strings.HasPrefix(string(d.FullName()), unknownPrefix) {
   271  		return proto.String(string(d.FullName()[len(unknownPrefix):]))
   272  	}
   273  	return proto.String("." + string(d.FullName()))
   274  }
   275
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