如何汇总protobuf消息

Question

I have a protobuf message look like below:

message sample {
    optional int32 value1 = 1;
    optional int32 value2 = 2;
    ...
    optional int64 valuen = n;
}

There are lots of objects and I want to aggregate these objects. The normal method is:

void aggregate(ample& msg1, sample& msg2) {
  msg1.set_value1(msg1.value1() + msg2.value1());
  msg1.set_value1(msg1.value2() + msg2.value2());
  ...
  msg1.set_value1(msg1.valuen() + msg2.valuen());
}

Is there any way to simplify the code? I try MergeFrom method but it replace the optional field not add.

Answer 1

Protocol buffer is not build for that kind of manipulation. The problem is if you have a shallow structure of the message then it will be ok, if you are uncertain about the message structure that will create problem every time you have to change the message structure.

MergeFrom is great if you have 2 messages and you want to join their structures together, but you do not want this.

What you could have is a repeated field ( std vector ) to store the elements and aggregate them.