mirror of
https://github.com/genuinetools/reg.git
synced 2024-08-19 21:30:24 -04:00
140 lines
4.6 KiB
Go
140 lines
4.6 KiB
Go
![]() |
// Go support for Protocol Buffers - Google's data interchange format
|
||
|
//
|
||
|
// Copyright 2016 The Go Authors. All rights reserved.
|
||
|
// https://github.com/golang/protobuf
|
||
|
//
|
||
|
// Redistribution and use in source and binary forms, with or without
|
||
|
// modification, are permitted provided that the following conditions are
|
||
|
// met:
|
||
|
//
|
||
|
// * Redistributions of source code must retain the above copyright
|
||
|
// notice, this list of conditions and the following disclaimer.
|
||
|
// * Redistributions in binary form must reproduce the above
|
||
|
// copyright notice, this list of conditions and the following disclaimer
|
||
|
// in the documentation and/or other materials provided with the
|
||
|
// distribution.
|
||
|
// * Neither the name of Google Inc. nor the names of its
|
||
|
// contributors may be used to endorse or promote products derived from
|
||
|
// this software without specific prior written permission.
|
||
|
//
|
||
|
// THIS SOFTWARE IS PROVIDED BY THE COPYRIGHT HOLDERS AND CONTRIBUTORS
|
||
|
// "AS IS" AND ANY EXPRESS OR IMPLIED WARRANTIES, INCLUDING, BUT NOT
|
||
|
// LIMITED TO, THE IMPLIED WARRANTIES OF MERCHANTABILITY AND FITNESS FOR
|
||
|
// A PARTICULAR PURPOSE ARE DISCLAIMED. IN NO EVENT SHALL THE COPYRIGHT
|
||
|
// OWNER OR CONTRIBUTORS BE LIABLE FOR ANY DIRECT, INDIRECT, INCIDENTAL,
|
||
|
// SPECIAL, EXEMPLARY, OR CONSEQUENTIAL DAMAGES (INCLUDING, BUT NOT
|
||
|
// LIMITED TO, PROCUREMENT OF SUBSTITUTE GOODS OR SERVICES; LOSS OF USE,
|
||
|
// DATA, OR PROFITS; OR BUSINESS INTERRUPTION) HOWEVER CAUSED AND ON ANY
|
||
|
// THEORY OF LIABILITY, WHETHER IN CONTRACT, STRICT LIABILITY, OR TORT
|
||
|
// (INCLUDING NEGLIGENCE OR OTHERWISE) ARISING IN ANY WAY OUT OF THE USE
|
||
|
// OF THIS SOFTWARE, EVEN IF ADVISED OF THE POSSIBILITY OF SUCH DAMAGE.
|
||
|
|
||
|
package ptypes
|
||
|
|
||
|
// This file implements functions to marshal proto.Message to/from
|
||
|
// google.protobuf.Any message.
|
||
|
|
||
|
import (
|
||
|
"fmt"
|
||
|
"reflect"
|
||
|
"strings"
|
||
|
|
||
|
"github.com/golang/protobuf/proto"
|
||
|
"github.com/golang/protobuf/ptypes/any"
|
||
|
)
|
||
|
|
||
|
const googleApis = "type.googleapis.com/"
|
||
|
|
||
|
// AnyMessageName returns the name of the message contained in a google.protobuf.Any message.
|
||
|
//
|
||
|
// Note that regular type assertions should be done using the Is
|
||
|
// function. AnyMessageName is provided for less common use cases like filtering a
|
||
|
// sequence of Any messages based on a set of allowed message type names.
|
||
|
func AnyMessageName(any *any.Any) (string, error) {
|
||
|
if any == nil {
|
||
|
return "", fmt.Errorf("message is nil")
|
||
|
}
|
||
|
slash := strings.LastIndex(any.TypeUrl, "/")
|
||
|
if slash < 0 {
|
||
|
return "", fmt.Errorf("message type url %q is invalid", any.TypeUrl)
|
||
|
}
|
||
|
return any.TypeUrl[slash+1:], nil
|
||
|
}
|
||
|
|
||
|
// MarshalAny takes the protocol buffer and encodes it into google.protobuf.Any.
|
||
|
func MarshalAny(pb proto.Message) (*any.Any, error) {
|
||
|
value, err := proto.Marshal(pb)
|
||
|
if err != nil {
|
||
|
return nil, err
|
||
|
}
|
||
|
return &any.Any{TypeUrl: googleApis + proto.MessageName(pb), Value: value}, nil
|
||
|
}
|
||
|
|
||
|
// DynamicAny is a value that can be passed to UnmarshalAny to automatically
|
||
|
// allocate a proto.Message for the type specified in a google.protobuf.Any
|
||
|
// message. The allocated message is stored in the embedded proto.Message.
|
||
|
//
|
||
|
// Example:
|
||
|
//
|
||
|
// var x ptypes.DynamicAny
|
||
|
// if err := ptypes.UnmarshalAny(a, &x); err != nil { ... }
|
||
|
// fmt.Printf("unmarshaled message: %v", x.Message)
|
||
|
type DynamicAny struct {
|
||
|
proto.Message
|
||
|
}
|
||
|
|
||
|
// Empty returns a new proto.Message of the type specified in a
|
||
|
// google.protobuf.Any message. It returns an error if corresponding message
|
||
|
// type isn't linked in.
|
||
|
func Empty(any *any.Any) (proto.Message, error) {
|
||
|
aname, err := AnyMessageName(any)
|
||
|
if err != nil {
|
||
|
return nil, err
|
||
|
}
|
||
|
|
||
|
t := proto.MessageType(aname)
|
||
|
if t == nil {
|
||
|
return nil, fmt.Errorf("any: message type %q isn't linked in", aname)
|
||
|
}
|
||
|
return reflect.New(t.Elem()).Interface().(proto.Message), nil
|
||
|
}
|
||
|
|
||
|
// UnmarshalAny parses the protocol buffer representation in a google.protobuf.Any
|
||
|
// message and places the decoded result in pb. It returns an error if type of
|
||
|
// contents of Any message does not match type of pb message.
|
||
|
//
|
||
|
// pb can be a proto.Message, or a *DynamicAny.
|
||
|
func UnmarshalAny(any *any.Any, pb proto.Message) error {
|
||
|
if d, ok := pb.(*DynamicAny); ok {
|
||
|
if d.Message == nil {
|
||
|
var err error
|
||
|
d.Message, err = Empty(any)
|
||
|
if err != nil {
|
||
|
return err
|
||
|
}
|
||
|
}
|
||
|
return UnmarshalAny(any, d.Message)
|
||
|
}
|
||
|
|
||
|
aname, err := AnyMessageName(any)
|
||
|
if err != nil {
|
||
|
return err
|
||
|
}
|
||
|
|
||
|
mname := proto.MessageName(pb)
|
||
|
if aname != mname {
|
||
|
return fmt.Errorf("mismatched message type: got %q want %q", aname, mname)
|
||
|
}
|
||
|
return proto.Unmarshal(any.Value, pb)
|
||
|
}
|
||
|
|
||
|
// Is returns true if any value contains a given message type.
|
||
|
func Is(any *any.Any, pb proto.Message) bool {
|
||
|
aname, err := AnyMessageName(any)
|
||
|
if err != nil {
|
||
|
return false
|
||
|
}
|
||
|
|
||
|
return aname == proto.MessageName(pb)
|
||
|
}
|