diff -r 4f153a23adab -r 6d9efbef00a9 vendor/google.golang.org/protobuf/internal/filetype/build.go --- /dev/null Thu Jan 01 00:00:00 1970 +0000 +++ b/vendor/google.golang.org/protobuf/internal/filetype/build.go Sun Jul 11 10:35:56 2021 +0200 @@ -0,0 +1,297 @@ +// 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 filetype provides functionality for wrapping descriptors +// with Go type information. +package filetype + +import ( + "reflect" + + "google.golang.org/protobuf/internal/descopts" + fdesc "google.golang.org/protobuf/internal/filedesc" + pimpl "google.golang.org/protobuf/internal/impl" + pref "google.golang.org/protobuf/reflect/protoreflect" + preg "google.golang.org/protobuf/reflect/protoregistry" +) + +// Builder constructs type descriptors from a raw file descriptor +// and associated Go types for each enum and message declaration. +// +// +// Flattened Ordering +// +// The protobuf type system represents declarations as a tree. Certain nodes in +// the tree require us to either associate it with a concrete Go type or to +// resolve a dependency, which is information that must be provided separately +// since it cannot be derived from the file descriptor alone. +// +// However, representing a tree as Go literals is difficult to simply do in a +// space and time efficient way. Thus, we store them as a flattened list of +// objects where the serialization order from the tree-based form is important. +// +// The "flattened ordering" is defined as a tree traversal of all enum, message, +// extension, and service declarations using the following algorithm: +// +// def VisitFileDecls(fd): +// for e in fd.Enums: yield e +// for m in fd.Messages: yield m +// for x in fd.Extensions: yield x +// for s in fd.Services: yield s +// for m in fd.Messages: yield from VisitMessageDecls(m) +// +// def VisitMessageDecls(md): +// for e in md.Enums: yield e +// for m in md.Messages: yield m +// for x in md.Extensions: yield x +// for m in md.Messages: yield from VisitMessageDecls(m) +// +// The traversal starts at the root file descriptor and yields each direct +// declaration within each node before traversing into sub-declarations +// that children themselves may have. +type Builder struct { + // File is the underlying file descriptor builder. + File fdesc.Builder + + // GoTypes is a unique set of the Go types for all declarations and + // dependencies. Each type is represented as a zero value of the Go type. + // + // Declarations are Go types generated for enums and messages directly + // declared (not publicly imported) in the proto source file. + // Messages for map entries are accounted for, but represented by nil. + // Enum declarations in "flattened ordering" come first, followed by + // message declarations in "flattened ordering". + // + // Dependencies are Go types for enums or messages referenced by + // message fields (excluding weak fields), for parent extended messages of + // extension fields, for enums or messages referenced by extension fields, + // and for input and output messages referenced by service methods. + // Dependencies must come after declarations, but the ordering of + // dependencies themselves is unspecified. + GoTypes []interface{} + + // DependencyIndexes is an ordered list of indexes into GoTypes for the + // dependencies of messages, extensions, or services. + // + // There are 5 sub-lists in "flattened ordering" concatenated back-to-back: + // 0. Message field dependencies: list of the enum or message type + // referred to by every message field. + // 1. Extension field targets: list of the extended parent message of + // every extension. + // 2. Extension field dependencies: list of the enum or message type + // referred to by every extension field. + // 3. Service method inputs: list of the input message type + // referred to by every service method. + // 4. Service method outputs: list of the output message type + // referred to by every service method. + // + // The offset into DependencyIndexes for the start of each sub-list + // is appended to the end in reverse order. + DependencyIndexes []int32 + + // EnumInfos is a list of enum infos in "flattened ordering". + EnumInfos []pimpl.EnumInfo + + // MessageInfos is a list of message infos in "flattened ordering". + // If provided, the GoType and PBType for each element is populated. + // + // Requirement: len(MessageInfos) == len(Build.Messages) + MessageInfos []pimpl.MessageInfo + + // ExtensionInfos is a list of extension infos in "flattened ordering". + // Each element is initialized and registered with the protoregistry package. + // + // Requirement: len(LegacyExtensions) == len(Build.Extensions) + ExtensionInfos []pimpl.ExtensionInfo + + // TypeRegistry is the registry to register each type descriptor. + // If nil, it uses protoregistry.GlobalTypes. + TypeRegistry interface { + RegisterMessage(pref.MessageType) error + RegisterEnum(pref.EnumType) error + RegisterExtension(pref.ExtensionType) error + } +} + +// Out is the output of the builder. +type Out struct { + File pref.FileDescriptor +} + +func (tb Builder) Build() (out Out) { + // Replace the resolver with one that resolves dependencies by index, + // which is faster and more reliable than relying on the global registry. + if tb.File.FileRegistry == nil { + tb.File.FileRegistry = preg.GlobalFiles + } + tb.File.FileRegistry = &resolverByIndex{ + goTypes: tb.GoTypes, + depIdxs: tb.DependencyIndexes, + fileRegistry: tb.File.FileRegistry, + } + + // Initialize registry if unpopulated. + if tb.TypeRegistry == nil { + tb.TypeRegistry = preg.GlobalTypes + } + + fbOut := tb.File.Build() + out.File = fbOut.File + + // Process enums. + enumGoTypes := tb.GoTypes[:len(fbOut.Enums)] + if len(tb.EnumInfos) != len(fbOut.Enums) { + panic("mismatching enum lengths") + } + if len(fbOut.Enums) > 0 { + for i := range fbOut.Enums { + tb.EnumInfos[i] = pimpl.EnumInfo{ + GoReflectType: reflect.TypeOf(enumGoTypes[i]), + Desc: &fbOut.Enums[i], + } + // Register enum types. + if err := tb.TypeRegistry.RegisterEnum(&tb.EnumInfos[i]); err != nil { + panic(err) + } + } + } + + // Process messages. + messageGoTypes := tb.GoTypes[len(fbOut.Enums):][:len(fbOut.Messages)] + if len(tb.MessageInfos) != len(fbOut.Messages) { + panic("mismatching message lengths") + } + if len(fbOut.Messages) > 0 { + for i := range fbOut.Messages { + if messageGoTypes[i] == nil { + continue // skip map entry + } + + tb.MessageInfos[i].GoReflectType = reflect.TypeOf(messageGoTypes[i]) + tb.MessageInfos[i].Desc = &fbOut.Messages[i] + + // Register message types. + if err := tb.TypeRegistry.RegisterMessage(&tb.MessageInfos[i]); err != nil { + panic(err) + } + } + + // As a special-case for descriptor.proto, + // locally register concrete message type for the options. + if out.File.Path() == "google/protobuf/descriptor.proto" && out.File.Package() == "google.protobuf" { + for i := range fbOut.Messages { + switch fbOut.Messages[i].Name() { + case "FileOptions": + descopts.File = messageGoTypes[i].(pref.ProtoMessage) + case "EnumOptions": + descopts.Enum = messageGoTypes[i].(pref.ProtoMessage) + case "EnumValueOptions": + descopts.EnumValue = messageGoTypes[i].(pref.ProtoMessage) + case "MessageOptions": + descopts.Message = messageGoTypes[i].(pref.ProtoMessage) + case "FieldOptions": + descopts.Field = messageGoTypes[i].(pref.ProtoMessage) + case "OneofOptions": + descopts.Oneof = messageGoTypes[i].(pref.ProtoMessage) + case "ExtensionRangeOptions": + descopts.ExtensionRange = messageGoTypes[i].(pref.ProtoMessage) + case "ServiceOptions": + descopts.Service = messageGoTypes[i].(pref.ProtoMessage) + case "MethodOptions": + descopts.Method = messageGoTypes[i].(pref.ProtoMessage) + } + } + } + } + + // Process extensions. + if len(tb.ExtensionInfos) != len(fbOut.Extensions) { + panic("mismatching extension lengths") + } + var depIdx int32 + for i := range fbOut.Extensions { + // For enum and message kinds, determine the referent Go type so + // that we can construct their constructors. + const listExtDeps = 2 + var goType reflect.Type + switch fbOut.Extensions[i].L1.Kind { + case pref.EnumKind: + j := depIdxs.Get(tb.DependencyIndexes, listExtDeps, depIdx) + goType = reflect.TypeOf(tb.GoTypes[j]) + depIdx++ + case pref.MessageKind, pref.GroupKind: + j := depIdxs.Get(tb.DependencyIndexes, listExtDeps, depIdx) + goType = reflect.TypeOf(tb.GoTypes[j]) + depIdx++ + default: + goType = goTypeForPBKind[fbOut.Extensions[i].L1.Kind] + } + if fbOut.Extensions[i].IsList() { + goType = reflect.SliceOf(goType) + } + + pimpl.InitExtensionInfo(&tb.ExtensionInfos[i], &fbOut.Extensions[i], goType) + + // Register extension types. + if err := tb.TypeRegistry.RegisterExtension(&tb.ExtensionInfos[i]); err != nil { + panic(err) + } + } + + return out +} + +var goTypeForPBKind = map[pref.Kind]reflect.Type{ + pref.BoolKind: reflect.TypeOf(bool(false)), + pref.Int32Kind: reflect.TypeOf(int32(0)), + pref.Sint32Kind: reflect.TypeOf(int32(0)), + pref.Sfixed32Kind: reflect.TypeOf(int32(0)), + pref.Int64Kind: reflect.TypeOf(int64(0)), + pref.Sint64Kind: reflect.TypeOf(int64(0)), + pref.Sfixed64Kind: reflect.TypeOf(int64(0)), + pref.Uint32Kind: reflect.TypeOf(uint32(0)), + pref.Fixed32Kind: reflect.TypeOf(uint32(0)), + pref.Uint64Kind: reflect.TypeOf(uint64(0)), + pref.Fixed64Kind: reflect.TypeOf(uint64(0)), + pref.FloatKind: reflect.TypeOf(float32(0)), + pref.DoubleKind: reflect.TypeOf(float64(0)), + pref.StringKind: reflect.TypeOf(string("")), + pref.BytesKind: reflect.TypeOf([]byte(nil)), +} + +type depIdxs []int32 + +// Get retrieves the jth element of the ith sub-list. +func (x depIdxs) Get(i, j int32) int32 { + return x[x[int32(len(x))-i-1]+j] +} + +type ( + resolverByIndex struct { + goTypes []interface{} + depIdxs depIdxs + fileRegistry + } + fileRegistry interface { + FindFileByPath(string) (pref.FileDescriptor, error) + FindDescriptorByName(pref.FullName) (pref.Descriptor, error) + RegisterFile(pref.FileDescriptor) error + } +) + +func (r *resolverByIndex) FindEnumByIndex(i, j int32, es []fdesc.Enum, ms []fdesc.Message) pref.EnumDescriptor { + if depIdx := int(r.depIdxs.Get(i, j)); int(depIdx) < len(es)+len(ms) { + return &es[depIdx] + } else { + return pimpl.Export{}.EnumDescriptorOf(r.goTypes[depIdx]) + } +} + +func (r *resolverByIndex) FindMessageByIndex(i, j int32, es []fdesc.Enum, ms []fdesc.Message) pref.MessageDescriptor { + if depIdx := int(r.depIdxs.Get(i, j)); depIdx < len(es)+len(ms) { + return &ms[depIdx-len(es)] + } else { + return pimpl.Export{}.MessageDescriptorOf(r.goTypes[depIdx]) + } +}