1// Copyright 2016 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 5package ptypes 6 7import ( 8 "fmt" 9 "strings" 10 11 "github.com/golang/protobuf/proto" 12 "google.golang.org/protobuf/reflect/protoreflect" 13 "google.golang.org/protobuf/reflect/protoregistry" 14 15 anypb "github.com/golang/protobuf/ptypes/any" 16) 17 18const urlPrefix = "type.googleapis.com/" 19 20// AnyMessageName returns the message name contained in an anypb.Any message. 21// Most type assertions should use the Is function instead. 22func AnyMessageName(any *anypb.Any) (string, error) { 23 name, err := anyMessageName(any) 24 return string(name), err 25} 26func anyMessageName(any *anypb.Any) (protoreflect.FullName, error) { 27 if any == nil { 28 return "", fmt.Errorf("message is nil") 29 } 30 name := protoreflect.FullName(any.TypeUrl) 31 if i := strings.LastIndex(any.TypeUrl, "/"); i >= 0 { 32 name = name[i+len("/"):] 33 } 34 if !name.IsValid() { 35 return "", fmt.Errorf("message type url %q is invalid", any.TypeUrl) 36 } 37 return name, nil 38} 39 40// MarshalAny marshals the given message m into an anypb.Any message. 41func MarshalAny(m proto.Message) (*anypb.Any, error) { 42 switch dm := m.(type) { 43 case DynamicAny: 44 m = dm.Message 45 case *DynamicAny: 46 if dm == nil { 47 return nil, proto.ErrNil 48 } 49 m = dm.Message 50 } 51 b, err := proto.Marshal(m) 52 if err != nil { 53 return nil, err 54 } 55 return &anypb.Any{TypeUrl: urlPrefix + proto.MessageName(m), Value: b}, nil 56} 57 58// Empty returns a new message of the type specified in an anypb.Any message. 59// It returns protoregistry.NotFound if the corresponding message type could not 60// be resolved in the global registry. 61func Empty(any *anypb.Any) (proto.Message, error) { 62 name, err := anyMessageName(any) 63 if err != nil { 64 return nil, err 65 } 66 mt, err := protoregistry.GlobalTypes.FindMessageByName(name) 67 if err != nil { 68 return nil, err 69 } 70 return proto.MessageV1(mt.New().Interface()), nil 71} 72 73// UnmarshalAny unmarshals the encoded value contained in the anypb.Any message 74// into the provided message m. It returns an error if the target message 75// does not match the type in the Any message or if an unmarshal error occurs. 76// 77// The target message m may be a *DynamicAny message. If the underlying message 78// type could not be resolved, then this returns protoregistry.NotFound. 79func UnmarshalAny(any *anypb.Any, m proto.Message) error { 80 if dm, ok := m.(*DynamicAny); ok { 81 if dm.Message == nil { 82 var err error 83 dm.Message, err = Empty(any) 84 if err != nil { 85 return err 86 } 87 } 88 m = dm.Message 89 } 90 91 anyName, err := AnyMessageName(any) 92 if err != nil { 93 return err 94 } 95 msgName := proto.MessageName(m) 96 if anyName != msgName { 97 return fmt.Errorf("mismatched message type: got %q want %q", anyName, msgName) 98 } 99 return proto.Unmarshal(any.Value, m) 100} 101 102// Is reports whether the Any message contains a message of the specified type. 103func Is(any *anypb.Any, m proto.Message) bool { 104 if any == nil || m == nil { 105 return false 106 } 107 name := proto.MessageName(m) 108 if !strings.HasSuffix(any.TypeUrl, name) { 109 return false 110 } 111 return len(any.TypeUrl) == len(name) || any.TypeUrl[len(any.TypeUrl)-len(name)-1] == '/' 112} 113 114// DynamicAny is a value that can be passed to UnmarshalAny to automatically 115// allocate a proto.Message for the type specified in an anypb.Any message. 116// The allocated message is stored in the embedded proto.Message. 117// 118// Example: 119// var x ptypes.DynamicAny 120// if err := ptypes.UnmarshalAny(a, &x); err != nil { ... } 121// fmt.Printf("unmarshaled message: %v", x.Message) 122type DynamicAny struct{ proto.Message } 123 124func (m DynamicAny) String() string { 125 if m.Message == nil { 126 return "<nil>" 127 } 128 return m.Message.String() 129} 130func (m DynamicAny) Reset() { 131 if m.Message == nil { 132 return 133 } 134 m.Message.Reset() 135} 136func (m DynamicAny) ProtoMessage() { 137 return 138} 139func (m DynamicAny) ProtoReflect() protoreflect.Message { 140 if m.Message == nil { 141 return nil 142 } 143 return dynamicAny{proto.MessageReflect(m.Message)} 144} 145 146type dynamicAny struct{ protoreflect.Message } 147 148func (m dynamicAny) Type() protoreflect.MessageType { 149 return dynamicAnyType{m.Message.Type()} 150} 151func (m dynamicAny) New() protoreflect.Message { 152 return dynamicAnyType{m.Message.Type()}.New() 153} 154func (m dynamicAny) Interface() protoreflect.ProtoMessage { 155 return DynamicAny{proto.MessageV1(m.Message.Interface())} 156} 157 158type dynamicAnyType struct{ protoreflect.MessageType } 159 160func (t dynamicAnyType) New() protoreflect.Message { 161 return dynamicAny{t.MessageType.New()} 162} 163func (t dynamicAnyType) Zero() protoreflect.Message { 164 return dynamicAny{t.MessageType.Zero()} 165} 166