istio.io/istio@v0.0.0-20240520182934-d79c90f27776/istioctl/pkg/util/proto/messageslice.go (about)

     1  // Copyright Istio Authors
     2  //
     3  // Licensed under the Apache License, Version 2.0 (the "License");
     4  // you may not use this file except in compliance with the License.
     5  // You may obtain a copy of the License at
     6  //
     7  //     http://www.apache.org/licenses/LICENSE-2.0
     8  //
     9  // Unless required by applicable law or agreed to in writing, software
    10  // distributed under the License is distributed on an "AS IS" BASIS,
    11  // WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
    12  // See the License for the specific language governing permissions and
    13  // limitations under the License.
    14  
    15  package proto
    16  
    17  import (
    18  	"bytes"
    19  
    20  	"google.golang.org/protobuf/proto"
    21  
    22  	"istio.io/istio/pkg/util/protomarshal"
    23  )
    24  
    25  // MessageSlice allows us to marshal slices of protobuf messages like clusters/listeners/routes/endpoints correctly
    26  type MessageSlice []proto.Message
    27  
    28  // MarshalJSON handles marshaling of slices of proto messages
    29  func (pSlice MessageSlice) MarshalJSON() ([]byte, error) {
    30  	buffer := bytes.NewBufferString("[")
    31  	sliceLength := len(pSlice)
    32  	for index, msg := range pSlice {
    33  		b, err := protomarshal.Marshal(msg)
    34  		if err != nil {
    35  			return nil, err
    36  		}
    37  		buffer.Write(b)
    38  		if index < sliceLength-1 {
    39  			buffer.WriteString(",")
    40  		}
    41  	}
    42  	buffer.WriteString("]")
    43  	return buffer.Bytes(), nil
    44  }