JsonSubTypes VS Protobuf

If messages are arriving as Json you can use JsonSubTypes to deserialize to different DTOs based on the UUIDs (https://github.com/manuc66/JsonSubTypes) and then use the visitor pattern to dispatch the DTOs to the correct method.

Personally I've had good success with JsonSubTypes for deserializing discriminated unions from JSON. It'll serialize stuff into the right type, and then you just need a switch statement to typecast it afterwards.

There is a small use case that I consider valid for this. It would be for determining a set of pre-defined behaviors to make available to definitions of entities in a game. And the json data would not be coming from external sources, it would be tightly controlled by me as the developer. The response you made to the other comment on my post shared a link that said the practice shouldn't be done with untrusted data, and there would be no untrusted data since there'd be no external data. The article also mentions to restrict the types that can be deserialized, and that is definitely possible. The architecture pattern for this is ECS (Entity Component System) and the data-drive portion might have been a mis-naming of my post, it's more of a lot of the design of entities and components is stored in data files, and there are a few cases where I will want to associate certain functionality in the code with these data entity definitions. No operating system level functionality would be exposed. I've even been referred to a library available via nuget that will allow for what I'm attempting to do: https://github.com/manuc66/JsonSubTypes

It's because they changed the versioning format: https://github.com/protocolbuffers/protobuf/releases?page=5

But I suppose old version still receive bugfixes.

For at least 4 years protobuf has had decent support for self-describing messages (very similar to avro) as well as reflection

https://github.com/protocolbuffers/protobuf/blob/main/src/go...

Xgooglers trying to make do on the cheap will just create a Union of all their messages and include the message def in a self-describing message pattern. Super-sensitive network I/O can elide the message def (empty buffer) and any for RecordIO clone well file compression takes care of the definition.

Definitely useful to be able to dig out old defs but protobuf maintainers have surprisingly added useful features so you don’t have to.

Bonus points tho for extracting the protobuf defs that e.g. Apple bakes into their binaries.

gRPC Gateway is a protoc plugin that reads gRPC service definitions and generates a reverse proxy server that translates a RESTful JSON API into gRPC.

To use more recent versions of protoc in future applications, you can download them from the Protobuf repository.

Use the Protobuf CLI protoc and the plugin protoc-gen-tonic.

> didn’t find any standard for separating protobuf messages

The fact that protobufs are not self-delimiting is an endless source of frustration, but I know of 2 standards:

- SerializeDelimited* is part of the protobuf library: https://github.com/protocolbuffers/protobuf/blob/main/src/go...

- Riegeli is "a file format for storing a sequence of string records, typically serialized protocol buffers. It supports dense compression, fast decoding, seeking, detection and optional skipping of data corruption, filtering of proto message fields for even faster decoding, and parallel encoding": https://github.com/google/riegeli

It looks like it is in fact universal. Just glancing at the code here, it looks like the tool searches any arbitrary file for bytes that look like encoded protobuf descriptors, specifically looking for bytes that are plausibly the beginning of a FileDescriptorProto message defined here:

https://github.com/protocolbuffers/protobuf/blob/main/src/go...

This takes advantage of the fact that such descriptors are commonly compiled into programs that use protobuf. The descriptors are usually embedded as constant byte arrays. That said, not all protobuf implementations embed the descriptors and those that do often have an option to inhibit such embedding (at the expense of losing some dynamic introspection features).

Not much. You can check the source code in https://github.com/protocolbuffers/protobuf. For example, for serializing a boolean in C#: https://github.com/protocolbuffers/protobuf/blob/main/csharp/src/Google.Protobuf/WritingPrimitives.cs#L165. Strings and objects are a bit more complicated, but it is all about turning the data into its byte representation.