Rust

Install

cargo add honker

Enable experimental watcher backends when you need them:

honker = { version = "0.3", features = ["kernel-watcher", "shm-fast-path"] }

Open

use honker::{Database, OpenOptions};

let opts = OpenOptions::default().watcher_backend("shm")?;
let db = Database::open_with_options("app.db", opts)?;

The Rust binding registers Honker functions directly through honker-core; it does not need to load a .so / .dylib at runtime.

Queue

use honker::{EnqueueOpts, QueueOpts};
use serde_json::json;

let q = db.queue("emails", QueueOpts::default());
q.enqueue(&json!({"to": "alice@example.com"}), EnqueueOpts::default())?;

if let Some(job) = q.claim_one("worker-1")? {
    job.ack()?;
}

Transactional Outbox

let outbox = db.outbox("email", Default::default());

let tx = db.transaction()?;
tx.execute("INSERT INTO orders (id, total) VALUES (?1, ?2)", (42, 9900))?;
outbox.enqueue_tx(&tx, &json!({"order_id": 42}), Default::default())?;
tx.commit()?;

Run delivery workers in a separate process so crashes and restarts preserve the same database-backed retry semantics.

ORM Section

For new Rust apps, prefer the native honker crate. For existing sqlx SQLite apps, load the Honker extension on the same pool connection and execute honker_* SQL inside the sqlx::Transaction.

See the full Rust ORM recipe for sqlx wiring and the tradeoff between native rusqlite wrappers and ORM-owned connections.

Testing

Use tempfile::tempdir() plus a real .db path. If you are testing shm, keep a connection open while subprocess workers run so SQLite’s WAL-index file does not disappear between process opens.