Protobuf VS cereal

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.

One of the key feature of gRPC is protobuf .proto file(nothing but just a contract for me between two communicator code components) This file and protobuff compiler is so mature, then it generates a direct client implementation using protoccompiler. ref

I'd stick with cereal for serialization

Today I'm back to working on Pataro, the roguelike built on libtcod that made up much of my Hacktoberfest efforts. I had been assigned to an issue requesting the addition of serialization and deserialization, but unfortunately ran out of time and wasn't able to finish the former or start the latter. I ran into issues with Cereal, and had a hard time figuring out the structure of the program and how to go about implementing serialization for all the relevant components. At the end of that attempt I mentioned that if I were to try again I'd start by testing out Cereal separately and getting a handle on that before trying to implement it in Pataro - so that's what I'm doing today.

I am once again working on Pataro today, and I've succeeded in clearing up some issues and creating new ones. I've been stuck on an issue where Visual Studio was raising errors in the portion of the code where I call the cereal archive on some types, but was able to clear up that issue by moving the save function definitions out of their respective headers and into the corresponding .cpp files. Examining this repo and its use of cereal again, I was able to get a bit clearer of an idea of how it's implemented, and I included just about every relevant cereal header I could find to try and avoid any issues like the previous one popping up again (with the intention of later removing whichever I can to avoid redundant inclusions).

On the Pataro front, I've started looking at other examples of people using cereal for their games. It seems to be a popular choice for roguelike games like this, so hopefully I can figure out both the syntax problems I'm facing, as well as logical ones like how the program should be structured to have all the necessary data properly serialized and deserialized.

Progress on one front but roadblocks on another. After my post yesterday outlining my plans to add serialization to Pataro I ran into some issues with calling the archive class in cereal wherein the call wouldn't go through due to an incorrect number of arguments. This happened with both vector and size_t data members, and I'm still investigating why.

This is the simplest serialization library I saw. You only need to add one method to your class and you can stream it to desired archive. It supports binary as well as json, XML and others. https://github.com/USCiLab/cereal