Protobuf VS json

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 have not done a "desktop" program in 25+ years and never using C++ (or C), since then I'm mostly a web developer (PHP,Elixir, JS, Kotlin etc).

I'm currently doing a C++ audio plugin with the Juce framework.

This website has been a good resource, alongside https://www.learncpp.com

But I was actually close to give up before using those two things:

- https://github.com/nlohmann/json : my plugin use a json api backend and the Juce json implementation is atrocious (apparently because of being born in previous c++ version), but this library is GREAT.

- ChatGPT 4. I'm not sure I would have "succeeded" without it, at least not in a reasonable time frame. ChatGPT 3.5 is slow and does not give good results for my use case but 4 is impressive. And I use in a very dumb way, just posing question in the web UI. I probably could have it directly in MSVC?

Also I must say, for all its flaws, I have a renewed appreciation for doing UI on the web ;)

https://github.com/nlohmann/json works well for me

cmake_minimum_required(VERSION 3.15) project(xrpc++ DESCRIPTION "C++ AT Protocol XRPC library" VERSION 1.0.0 LANGUAGES CXX) include(FetchContent) FetchContent_Declare(cpr GIT_REPOSITORY https://github.com/libcpr/cpr.git GIT_TAG 2553fc41450301cd09a9271c8d2c3e0cf3546b73) # The commit hash for 1.10.x. Replace with the latest from: https://github.com/libcpr/cpr/releases FetchContent_MakeAvailable(cpr) FetchContent_Declare(json URL https://github.com/nlohmann/json/releases/download/v3.11.2/json.tar.xz) FetchContent_MakeAvailable(json) add_library(${PROJECT_NAME} SHARED src/lexicon.cpp src/xrpc.cpp ) target_link_libraries(${PROJECT_NAME} PRIVATE cpr::cpr) target_link_libraries(${PROJECT_NAME} PRIVATE nlohmann_json::nlohmann_json) set_target_properties(${PROJECT_NAME} PROPERTIES VERSION ${PROJECT_VERSION}) set_target_properties(${PROJECT_NAME} PROPERTIES SOVERSION 1) target_include_directories(${PROJECT_NAME} PUBLIC include) set(CMAKE_BUILD_TYPE debug)

FetchContent_Declare(json URL https://github.com/nlohmann/json/releases/download/v3.11.2/json.tar.xz) FetchContent_MakeAvailable(json)

Here is one popular C++ library (nlohmann/json) removing its use.

Before going into binary serialization I suggest you to get comfortable with serialization to text. You can try to write your data to text files and read them in again. Then after you get an idea of how this works you can try to use a library that writes to XML or json, e.g. nlohmann json

Download the single header file json.hpp from https://github.com/nlohmann/json/releases and place it in your project directory or an include directory.

Exemple of a JSON library: https://github.com/nlohmann/json (For XML, there's tinyxml)