github.com/gravitational/teleport/api@v0.0.0-20240507183017-3110591cbafc/utils/protobuf.go (about)

     1  /*
     2  Copyright 2023 Gravitational, Inc.
     3  
     4  Licensed under the Apache License, Version 2.0 (the "License");
     5  you may not use this file except in compliance with the License.
     6  You may obtain a copy of the License at
     7  
     8      http://www.apache.org/licenses/LICENSE-2.0
     9  
    10  Unless required by applicable law or agreed to in writing, software
    11  distributed under the License is distributed on an "AS IS" BASIS,
    12  WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    13  See the License for the specific language governing permissions and
    14  limitations under the License.
    15  */
    16  
    17  package utils
    18  
    19  import (
    20  	"google.golang.org/protobuf/proto"
    21  	"google.golang.org/protobuf/protoadapt"
    22  )
    23  
    24  // CloneProtoMsg returns a deep copy of msg. Modifying the returned
    25  // protobuf message will not affect msg. If msg contains any empty
    26  // slices, the returned copy will have nil slices instead.
    27  func CloneProtoMsg[T protoadapt.MessageV1](msg T) T {
    28  	// github.com/golang/protobuf/proto.Clone panics when trying to
    29  	// copy a map[K]V where the type of V is a slice of anything
    30  	// other than byte. See https://github.com/gogo/protobuf/issues/14
    31  	msgV2 := protoadapt.MessageV2Of(msg)
    32  	msgV2 = proto.Clone(msgV2)
    33  	// this is safe as protoadapt.MessageV2Of will simply wrap the message
    34  	// with a type that implements the protobuf v2 API, and
    35  	// protoadapt.MessageV1Of will return the unwrapped message
    36  	return protoadapt.MessageV1Of(msgV2).(T)
    37  }