For a slow protocol like protobufs that is rarely streamed, I agree a length prefix should be the default One way to make streaming work is just to allow the l

For a slow protocol like protobufs that is rarely streamed, I agree a length prefix should be the default One way to make streaming work is just to allow the length value to be bigger than needed and add a padding scheme at the end of the message. This is overhead free in terms of processing time since fields must be decoded sequentially anyway.