a934ead904
Implements the `json_extract` function. In the meantime, the json path has already been implemented by @petersooley in https://github.com/tursodatabase/limbo/pull/555 which is a requirement for `json_extract`. However, this PR takes a different approach and parses the JSON path using the JSON grammar, because there are a lot of quirks in how a JSON `key` can look (see the JSON grammar in the Pest file). The downside is that it allocates more memory than the current implementation, but might be easier to maintain in the long run. I included a lot of tests with some quirky behavior of the `json_extract` (some of them still need some work). I also noticed that these changed between sqlite versions (had `SQLite 3.43.2` locally and `3.45` gave different results). Due to this, I'm not sure how much value there is in trying to be fully compatible with SQLite. Perhaps the approach taken by @petersooley solves 99% of use-cases? Reviewed-by: Jussi Saurio <jussi.saurio@gmail.com> Closes #524
Limbo
Limbo is a work-in-progress, in-process OLTP database management system, compatible with SQLite.
Features
- In-process OLTP database engine library
- Asynchronous I/O support on Linux with
io_uring - SQLite compatibility (status)
- SQL dialect support
- File format support
- SQLite C API
- JavaScript/WebAssembly bindings (wip)
- Support for Linux, macOS, and Windows
Getting Started
CLI
Install limbo with:
curl --proto '=https' --tlsv1.2 -LsSf \
https://github.com/penberg/limbo/releases/latest/download/limbo-installer.sh | sh
Then use the SQL shell to create and query a database:
$ limbo database.db
Limbo v0.0.6
Enter ".help" for usage hints.
limbo> CREATE TABLE users (id INT PRIMARY KEY, username TEXT);
limbo> INSERT INTO users VALUES (1, 'alice');
limbo> INSERT INTO users VALUES (2, 'bob');
limbo> SELECT * FROM users;
1|alice
2|bob
JavaScript (wip)
Installation:
npm i limbo-wasm
Example usage:
import { Database } from 'limbo-wasm';
const db = new Database('sqlite.db');
const stmt = db.prepare('SELECT * FROM users');
const users = stmt.all();
console.log(users);
Python (wip)
pip install pylimbo
Example usage:
import limbo
con = limbo.connect("sqlite.db")
cur = con.cursor()
res = cur.execute("SELECT * FROM users")
print(res.fetchone())
Developing
Build and run limbo cli:
cargo run --package limbo --bin limbo database.db
Run tests:
cargo test
Test coverage report:
cargo tarpaulin -o html
Run benchmarks:
cargo bench
Run benchmarks and generate flamegraphs:
echo -1 | sudo tee /proc/sys/kernel/perf_event_paranoid
cargo bench --bench benchmark -- --profile-time=5
FAQ
How is Limbo different from libSQL?
Limbo is a research project to build a SQLite compatible in-process database in Rust with native async support. The libSQL project, on the other hand, is an open source, open contribution fork of SQLite, with focus on production features such as replication, backups, encryption, and so on. There is no hard dependency between the two projects. Of course, if Limbo becomes widely successful, we might consider merging with libSQL, but that is something that will be decided in the future.
Publications
- Pekka Enberg, Sasu Tarkoma, Jon Crowcroft Ashwin Rao (2024). Serverless Runtime / Database Co-Design With Asynchronous I/O. In EdgeSys ‘24. [PDF]
- Pekka Enberg, Sasu Tarkoma, and Ashwin Rao (2023). Towards Database and Serverless Runtime Co-Design. In CoNEXT-SW ’23. [PDF] [Slides]
Contributing
We'd love to have you contribute to Limbo! Check out the contribution guide to get started.
License
This project is licensed under the MIT license.
Contribution
Unless you explicitly state otherwise, any contribution intentionally submitted for inclusion in Limbo by you, shall be licensed as MIT, without any additional terms or conditions.