summaryrefslogtreecommitdiffstats
path: root/vendor/google.golang.org/protobuf/internal/impl/legacy_enum.go
diff options
context:
space:
mode:
authorWim <wim@42.be>2020-08-10 00:29:54 +0200
committerGitHub <noreply@github.com>2020-08-10 00:29:54 +0200
commit4e50fd864921c556988c919269448efdb90fa961 (patch)
treea3625f03f8de3c4f3841364000a4ea3aa42c1533 /vendor/google.golang.org/protobuf/internal/impl/legacy_enum.go
parentdfdffa0027334e55ce213fc6eb62206dbf48baf6 (diff)
downloadmatterbridge-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.go219
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, "."))
+}