protobuf-net 可以输出将用于 C++ 代码生成的 proto 文件吗？

Question

I'm trying to figure out if protobuf-net is capable of generating .proto files that then can be used with the regular Protobuf compiler to compile C++ classes.

I looked at those questions

• Protobuf-net.proto file generation for inheritance

• protobuf-net inheritance shows base class in.proto file

• Protobuf-net is incompatible with official google Protobuf for C++ (message encoding)

But they are really old and talk about V2 Protobuff syntax.

My goal is to write a class hierarchy in C# and then use protobuf-net to generate .proto file for said hierarchy. Then I want to use the official Google Complier to generate C++ code based on that hierarchy.

The end result should have field and data parity between C# and C++ so that messages could be exchanged.

Is this possible?

I'll try to provide an example.

Suppose I have the following code in C#:(Might have some syntactic mistakes as I typed it out quickly in notepad)

public class Point{
    public double x;
    public double y;
}

public abstract class Polygon{
    public List<Point> Vertices;

    public Polygon(){
        Vertecies = new();
    }

    public override ToString(){
        string ans = "";
        foreach(var point in Vertecies){
            ans += $"({point.x},{point.y})"
        }
        return ans;
    }
}

public class Square: Polygon{

    public Sqare(Point a, Point b, Point c Point d){
        this.Vertices.Add(a);
        this.Vertices.Add(b);
        this.Vertices.Add(c);
        this.Vertices.Add(d);
    }
}

public class Triangle: Polygon{

    public Triangle(Point a, Point b, Point c){
        this.Vertices.Add(a);
        this.Vertices.Add(b);
        this.Vertices.Add(c);        
    }
}
    

I want to use protobuf-net to generate a .proto file to generate this same hierarchy in C++.

My question is: If this is possible with protobuf-net ? If you think further information is missing, please tell me what is missing and I'll provide it.

Answer 1

Yes and no. Protobuf-net supports both proto2 and proto3, so: that's fine - and it usually does a good enough job in GetSchema/GetProto to work fine. The problem I see if your specific model, however, is: inheritance. Protobuf doesn't really do inheritance. Protobuf-net can fake it, in a way that is compatible with oneof in.proto terms, but: it isn't ideal . It you want a model that maps well to cross-platform usage, you mostly need to start with the simple model that is supported by.proto, which doesn't include that.

But: annotate the model and give it a whirl!