Is it possible to alter (append, merge, etc) a serialized protobuf
message without having to unmarshal it first? I'm using the golang/protobuf package.
Ideally I would like to have a service that can receive incoming serialized messages, append some fields on-the-fly, then pass the message along to the next service -kind of like middleware, where additional information can just be added to the payload without having to constantly unmarshal and marshal.
Some context: the system is realtime, so I'd like to minimize overhead wherever possible.