| // Copyright 2019 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 filedesc provides functionality for constructing descriptors. |
| // |
| // The types in this package implement interfaces in the protoreflect package |
| // related to protobuf descripriptors. |
| package filedesc |
| |
| import ( |
| "google.golang.org/protobuf/encoding/protowire" |
| "google.golang.org/protobuf/internal/genid" |
| "google.golang.org/protobuf/reflect/protoreflect" |
| "google.golang.org/protobuf/reflect/protoregistry" |
| ) |
| |
| // Builder construct a protoreflect.FileDescriptor from the raw descriptor. |
| type Builder struct { |
| // GoPackagePath is the Go package path that is invoking this builder. |
| GoPackagePath string |
| |
| // RawDescriptor is the wire-encoded bytes of FileDescriptorProto |
| // and must be populated. |
| RawDescriptor []byte |
| |
| // NumEnums is the total number of enums declared in the file. |
| NumEnums int32 |
| // NumMessages is the total number of messages declared in the file. |
| // It includes the implicit message declarations for map entries. |
| NumMessages int32 |
| // NumExtensions is the total number of extensions declared in the file. |
| NumExtensions int32 |
| // NumServices is the total number of services declared in the file. |
| NumServices int32 |
| |
| // TypeResolver resolves extension field types for descriptor options. |
| // If nil, it uses protoregistry.GlobalTypes. |
| TypeResolver interface { |
| protoregistry.ExtensionTypeResolver |
| } |
| |
| // FileRegistry is use to lookup file, enum, and message dependencies. |
| // Once constructed, the file descriptor is registered here. |
| // If nil, it uses protoregistry.GlobalFiles. |
| FileRegistry interface { |
| FindFileByPath(string) (protoreflect.FileDescriptor, error) |
| FindDescriptorByName(protoreflect.FullName) (protoreflect.Descriptor, error) |
| RegisterFile(protoreflect.FileDescriptor) error |
| } |
| } |
| |
| // resolverByIndex is an interface Builder.FileRegistry may implement. |
| // If so, it permits looking up an enum or message dependency based on the |
| // sub-list and element index into filetype.Builder.DependencyIndexes. |
| type resolverByIndex interface { |
| FindEnumByIndex(int32, int32, []Enum, []Message) protoreflect.EnumDescriptor |
| FindMessageByIndex(int32, int32, []Enum, []Message) protoreflect.MessageDescriptor |
| } |
| |
| // Indexes of each sub-list in filetype.Builder.DependencyIndexes. |
| const ( |
| listFieldDeps int32 = iota |
| listExtTargets |
| listExtDeps |
| listMethInDeps |
| listMethOutDeps |
| ) |
| |
| // Out is the output of the Builder. |
| type Out struct { |
| File protoreflect.FileDescriptor |
| |
| // Enums is all enum descriptors in "flattened ordering". |
| Enums []Enum |
| // Messages is all message descriptors in "flattened ordering". |
| // It includes the implicit message declarations for map entries. |
| Messages []Message |
| // Extensions is all extension descriptors in "flattened ordering". |
| Extensions []Extension |
| // Service is all service descriptors in "flattened ordering". |
| Services []Service |
| } |
| |
| // Build constructs a FileDescriptor given the parameters set in Builder. |
| // It assumes that the inputs are well-formed and panics if any inconsistencies |
| // are encountered. |
| // |
| // If NumEnums+NumMessages+NumExtensions+NumServices is zero, |
| // then Build automatically derives them from the raw descriptor. |
| func (db Builder) Build() (out Out) { |
| // Populate the counts if uninitialized. |
| if db.NumEnums+db.NumMessages+db.NumExtensions+db.NumServices == 0 { |
| db.unmarshalCounts(db.RawDescriptor, true) |
| } |
| |
| // Initialize resolvers and registries if unpopulated. |
| if db.TypeResolver == nil { |
| db.TypeResolver = protoregistry.GlobalTypes |
| } |
| if db.FileRegistry == nil { |
| db.FileRegistry = protoregistry.GlobalFiles |
| } |
| |
| fd := newRawFile(db) |
| out.File = fd |
| out.Enums = fd.allEnums |
| out.Messages = fd.allMessages |
| out.Extensions = fd.allExtensions |
| out.Services = fd.allServices |
| |
| if err := db.FileRegistry.RegisterFile(fd); err != nil { |
| panic(err) |
| } |
| return out |
| } |
| |
| // unmarshalCounts counts the number of enum, message, extension, and service |
| // declarations in the raw message, which is either a FileDescriptorProto |
| // or a MessageDescriptorProto depending on whether isFile is set. |
| func (db *Builder) unmarshalCounts(b []byte, isFile bool) { |
| for len(b) > 0 { |
| num, typ, n := protowire.ConsumeTag(b) |
| b = b[n:] |
| switch typ { |
| case protowire.BytesType: |
| v, m := protowire.ConsumeBytes(b) |
| b = b[m:] |
| if isFile { |
| switch num { |
| case genid.FileDescriptorProto_EnumType_field_number: |
| db.NumEnums++ |
| case genid.FileDescriptorProto_MessageType_field_number: |
| db.unmarshalCounts(v, false) |
| db.NumMessages++ |
| case genid.FileDescriptorProto_Extension_field_number: |
| db.NumExtensions++ |
| case genid.FileDescriptorProto_Service_field_number: |
| db.NumServices++ |
| } |
| } else { |
| switch num { |
| case genid.DescriptorProto_EnumType_field_number: |
| db.NumEnums++ |
| case genid.DescriptorProto_NestedType_field_number: |
| db.unmarshalCounts(v, false) |
| db.NumMessages++ |
| case genid.DescriptorProto_Extension_field_number: |
| db.NumExtensions++ |
| } |
| } |
| default: |
| m := protowire.ConsumeFieldValue(num, typ, b) |
| b = b[m:] |
| } |
| } |
| } |