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author | Wim <wim@42.be> | 2020-08-10 00:29:54 +0200 |
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committer | GitHub <noreply@github.com> | 2020-08-10 00:29:54 +0200 |
commit | 4e50fd864921c556988c919269448efdb90fa961 (patch) | |
tree | a3625f03f8de3c4f3841364000a4ea3aa42c1533 /vendor/google.golang.org/protobuf/internal/impl/legacy_enum.go | |
parent | dfdffa0027334e55ce213fc6eb62206dbf48baf6 (diff) | |
download | matterbridge-msglm-4e50fd864921c556988c919269448efdb90fa961.tar.gz matterbridge-msglm-4e50fd864921c556988c919269448efdb90fa961.tar.bz2 matterbridge-msglm-4e50fd864921c556988c919269448efdb90fa961.zip |
Use mattermost v5 module (#1192)
Diffstat (limited to 'vendor/google.golang.org/protobuf/internal/impl/legacy_enum.go')
-rw-r--r-- | vendor/google.golang.org/protobuf/internal/impl/legacy_enum.go | 219 |
1 files changed, 219 insertions, 0 deletions
diff --git a/vendor/google.golang.org/protobuf/internal/impl/legacy_enum.go b/vendor/google.golang.org/protobuf/internal/impl/legacy_enum.go new file mode 100644 index 00000000..f7d7ffb5 --- /dev/null +++ b/vendor/google.golang.org/protobuf/internal/impl/legacy_enum.go @@ -0,0 +1,219 @@ +// Copyright 2018 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 impl + +import ( + "fmt" + "reflect" + "strings" + "sync" + + "google.golang.org/protobuf/internal/filedesc" + "google.golang.org/protobuf/internal/strs" + "google.golang.org/protobuf/reflect/protoreflect" + pref "google.golang.org/protobuf/reflect/protoreflect" +) + +// legacyEnumName returns the name of enums used in legacy code. +// It is neither the protobuf full name nor the qualified Go name, +// but rather an odd hybrid of both. +func legacyEnumName(ed pref.EnumDescriptor) string { + var protoPkg string + enumName := string(ed.FullName()) + if fd := ed.ParentFile(); fd != nil { + protoPkg = string(fd.Package()) + enumName = strings.TrimPrefix(enumName, protoPkg+".") + } + if protoPkg == "" { + return strs.GoCamelCase(enumName) + } + return protoPkg + "." + strs.GoCamelCase(enumName) +} + +// legacyWrapEnum wraps v as a protoreflect.Enum, +// where v must be a int32 kind and not implement the v2 API already. +func legacyWrapEnum(v reflect.Value) pref.Enum { + et := legacyLoadEnumType(v.Type()) + return et.New(pref.EnumNumber(v.Int())) +} + +var legacyEnumTypeCache sync.Map // map[reflect.Type]protoreflect.EnumType + +// legacyLoadEnumType dynamically loads a protoreflect.EnumType for t, +// where t must be an int32 kind and not implement the v2 API already. +func legacyLoadEnumType(t reflect.Type) pref.EnumType { + // Fast-path: check if a EnumType is cached for this concrete type. + if et, ok := legacyEnumTypeCache.Load(t); ok { + return et.(pref.EnumType) + } + + // Slow-path: derive enum descriptor and initialize EnumType. + var et pref.EnumType + ed := LegacyLoadEnumDesc(t) + et = &legacyEnumType{ + desc: ed, + goType: t, + } + if et, ok := legacyEnumTypeCache.LoadOrStore(t, et); ok { + return et.(pref.EnumType) + } + return et +} + +type legacyEnumType struct { + desc pref.EnumDescriptor + goType reflect.Type + m sync.Map // map[protoreflect.EnumNumber]proto.Enum +} + +func (t *legacyEnumType) New(n pref.EnumNumber) pref.Enum { + if e, ok := t.m.Load(n); ok { + return e.(pref.Enum) + } + e := &legacyEnumWrapper{num: n, pbTyp: t, goTyp: t.goType} + t.m.Store(n, e) + return e +} +func (t *legacyEnumType) Descriptor() pref.EnumDescriptor { + return t.desc +} + +type legacyEnumWrapper struct { + num pref.EnumNumber + pbTyp pref.EnumType + goTyp reflect.Type +} + +func (e *legacyEnumWrapper) Descriptor() pref.EnumDescriptor { + return e.pbTyp.Descriptor() +} +func (e *legacyEnumWrapper) Type() pref.EnumType { + return e.pbTyp +} +func (e *legacyEnumWrapper) Number() pref.EnumNumber { + return e.num +} +func (e *legacyEnumWrapper) ProtoReflect() pref.Enum { + return e +} +func (e *legacyEnumWrapper) protoUnwrap() interface{} { + v := reflect.New(e.goTyp).Elem() + v.SetInt(int64(e.num)) + return v.Interface() +} + +var ( + _ pref.Enum = (*legacyEnumWrapper)(nil) + _ unwrapper = (*legacyEnumWrapper)(nil) +) + +var legacyEnumDescCache sync.Map // map[reflect.Type]protoreflect.EnumDescriptor + +// LegacyLoadEnumDesc returns an EnumDescriptor derived from the Go type, +// which must be an int32 kind and not implement the v2 API already. +// +// This is exported for testing purposes. +func LegacyLoadEnumDesc(t reflect.Type) pref.EnumDescriptor { + // Fast-path: check if an EnumDescriptor is cached for this concrete type. + if ed, ok := legacyEnumDescCache.Load(t); ok { + return ed.(pref.EnumDescriptor) + } + + // Slow-path: initialize EnumDescriptor from the raw descriptor. + ev := reflect.Zero(t).Interface() + if _, ok := ev.(pref.Enum); ok { + panic(fmt.Sprintf("%v already implements proto.Enum", t)) + } + edV1, ok := ev.(enumV1) + if !ok { + return aberrantLoadEnumDesc(t) + } + b, idxs := edV1.EnumDescriptor() + + var ed pref.EnumDescriptor + if len(idxs) == 1 { + ed = legacyLoadFileDesc(b).Enums().Get(idxs[0]) + } else { + md := legacyLoadFileDesc(b).Messages().Get(idxs[0]) + for _, i := range idxs[1 : len(idxs)-1] { + md = md.Messages().Get(i) + } + ed = md.Enums().Get(idxs[len(idxs)-1]) + } + if ed, ok := legacyEnumDescCache.LoadOrStore(t, ed); ok { + return ed.(protoreflect.EnumDescriptor) + } + return ed +} + +var aberrantEnumDescCache sync.Map // map[reflect.Type]protoreflect.EnumDescriptor + +// aberrantLoadEnumDesc returns an EnumDescriptor derived from the Go type, +// which must not implement protoreflect.Enum or enumV1. +// +// If the type does not implement enumV1, then there is no reliable +// way to derive the original protobuf type information. +// We are unable to use the global enum registry since it is +// unfortunately keyed by the protobuf full name, which we also do not know. +// Thus, this produces some bogus enum descriptor based on the Go type name. +func aberrantLoadEnumDesc(t reflect.Type) pref.EnumDescriptor { + // Fast-path: check if an EnumDescriptor is cached for this concrete type. + if ed, ok := aberrantEnumDescCache.Load(t); ok { + return ed.(pref.EnumDescriptor) + } + + // Slow-path: construct a bogus, but unique EnumDescriptor. + ed := &filedesc.Enum{L2: new(filedesc.EnumL2)} + ed.L0.FullName = AberrantDeriveFullName(t) // e.g., github_com.user.repo.MyEnum + ed.L0.ParentFile = filedesc.SurrogateProto3 + ed.L2.Values.List = append(ed.L2.Values.List, filedesc.EnumValue{}) + + // TODO: Use the presence of a UnmarshalJSON method to determine proto2? + + vd := &ed.L2.Values.List[0] + vd.L0.FullName = ed.L0.FullName + "_UNKNOWN" // e.g., github_com.user.repo.MyEnum_UNKNOWN + vd.L0.ParentFile = ed.L0.ParentFile + vd.L0.Parent = ed + + // TODO: We could use the String method to obtain some enum value names by + // starting at 0 and print the enum until it produces invalid identifiers. + // An exhaustive query is clearly impractical, but can be best-effort. + + if ed, ok := aberrantEnumDescCache.LoadOrStore(t, ed); ok { + return ed.(pref.EnumDescriptor) + } + return ed +} + +// AberrantDeriveFullName derives a fully qualified protobuf name for the given Go type +// The provided name is not guaranteed to be stable nor universally unique. +// It should be sufficiently unique within a program. +// +// This is exported for testing purposes. +func AberrantDeriveFullName(t reflect.Type) pref.FullName { + sanitize := func(r rune) rune { + switch { + case r == '/': + return '.' + case 'a' <= r && r <= 'z', 'A' <= r && r <= 'Z', '0' <= r && r <= '9': + return r + default: + return '_' + } + } + prefix := strings.Map(sanitize, t.PkgPath()) + suffix := strings.Map(sanitize, t.Name()) + if suffix == "" { + suffix = fmt.Sprintf("UnknownX%X", reflect.ValueOf(t).Pointer()) + } + + ss := append(strings.Split(prefix, "."), suffix) + for i, s := range ss { + if s == "" || ('0' <= s[0] && s[0] <= '9') { + ss[i] = "x" + s + } + } + return pref.FullName(strings.Join(ss, ".")) +} |