Convert to protobuf format

Question

I have file with that text

 5 {
    1: "Capability"
    2 {
      1: "READ"
      2: 0
    }
    2 {
      1: "SSH"
      2: 12
    }
  }

I know that is a protobuf structure. How can I convert this data to normal protobuf file?

Protoc give me error message

Answer 1

"I know that is a protobuf structure."

That might have come from something protobuf related, but: it must have been a tortuous journey, because no: that isn't directly protobuf anything and AFAIK nothing is going to parse that "as is" - it isn't protobuf binary and it isn't the opinionated protobuf JSON variant. It looks like the output of protoc with the --decode_raw option? Note that this is for display purposes only.

However, let's see what we can infer, and reverse-engineer a protobuf schema; all we know about the root message is that it has another message as field 5; that thing has a string in field one, and some repeated message in field 2, with that inner-most message being a string and an integer in fields 1 and 2, so let's assume something like:

syntax = "proto3";

message MyRootMessage {
    Layer1 layer1 = 5;
}
message Layer1 {
    string name = 1;
    repeated Layer2 layer2 = 2;
}
message Layer2 {
    string name = 1;
    int32 number = 2;
}

so: you would compile that in your language of choice via protoc, and (again in your language of choice): populate it - for example:

var root = new MyRootMessage {
    Layer1 = new {
        Name = "Capability",
        Layer2s = {
            new { Name = "READ", Number = 0 },
            new { Name = "SSH", Number = 12 },
        }
    }
};

then serialize that using your chosen language/frameworks serialize API.

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Alternatively, if you still have the binary that you used with protoc --decode_raw, once you have reverse-engineered a schema by inspection (as above), you can construct a wrapper to deserialize your binary, using the normal code-gen options.