Objectbox for rust

Unofficial rust support for ObjectBox database.

See the example crate.

Example

extern crate objectbox;

use objectbox::{macros::entity, opt::Opt, store::Store};

mod objectbox_gen;
use objectbox_gen as ob;

#[derive(Debug)]
#[entity]
pub struct Entity {
    #[id]
    id: u64,
    hello: String,
}

fn main() {
    let mut model = ob::make_model();
    let opt = Opt::from_model(&mut model);
    let trait_map = ob::make_factory_map();
    let store = Store::new(opt, trait_map).expect("crash");

    let mut box1 = store.get_box::<Entity>().expect("crash");

    let mut e_before = Entity {
        id: 0,
        hello: "Hello world!".to_string(),
    };

    let new_id = box1.put(&mut e_before).expect("crash");

    match box1.get(new_id) {
        Err(err) => panic!("{err}"),
        Ok(found_item) => {
            if let Some(object) = found_item {
                println!("{}", object.hello);
            }
        }
    }
}

How the packages cooperate

The macros package

This is where the rust meta attributes are defined to parse structs, that triggers the build to produce files with the '.objectbox.info' suffix.

The generator package

Together, with the build.rs file, the entity.objectbox.info files are globbed and processed, to generate a objectbox-model.json file.

In the final stage, objectbox-model.json is used to generate all the necessary rust code to facilitate and access the basic and/or advanced features, in objectbox_gen.rs.

Dependencies

• InstallRustup, or get it from apt, brew, chocolatey, etc.
• llvm
• Also, make sure llvm-ar is also exported in $PATH

Abstract roadmap

• Fix String Query bugs, also write more tests
• Support fields with Option<P> where P is some primitive type
• Write more tests, especially for all condition ops

Problems solved, 2023 Feb-March

• Testing query conditions implementation
• Code generation from struct entities with macros
• Code generation for injecting the model to Store
• Weave traits to make blankets, so objects can be created, flattened, inflated.

Guidelines

• Don't rely on nightly features, we'll take whatever edition 2021 has to offer

TODO (Nice to haves)

• Reimplement macros with darling's
• Integrate: cleaner abstractions (example how).