# 🧊 drop-queue
**`drop-queue`** is a simple, composable async drop queue for Rust — built to run queued tasks in FIFO order and ensure graceful shutdown via draining. It's useful in lifecycle-managed environments (e.g., `notmad`) or as a lightweight alternative until async drop is stabilized in Rust.
> 💡 Tasks are executed one at a time. If the queue is marked for draining, no further items can be added.
---
## ✨ Features
* Assign one-off async tasks (closures) to a queue
* FIFO task processing
* Draining mechanism to flush the queue before shutdown
* Optional integration with [`notmad`](https://crates.io/crates/notmad) for graceful component lifecycle control
* `Send + Sync + 'static` guaranteed
---
## 🚀 Usage
### Add to `Cargo.toml`
```toml
[dependencies]
drop-queue = "*"
```
### Enable `notmad` integration (optional)
```toml
[dependencies]
drop-queue = { version = "*", features = ["notmad"] }
```
---
## 🛠 Example
```rust
use drop-queue::DropQueue;
use tokio::sync::oneshot;
#[tokio::main]
async fn main() -> anyhow::Result<()> {
let queue = DropQueue::new();
let (tx, rx) = oneshot::channel();
queue.assign(|| async move {
println!("Running closure task");
tx.send(()).unwrap();
Ok(())
})?;
queue.process_next().await?;
rx.await?;
Ok(())
}
```
---
## 🔁 Lifecycle with `notmad`
If using the [`notmad`](https://crates.io/crates/notmad) lifecycle framework:
```rust
#[tokio::main]
async fn main() -> anyhow::Result<()> {
let queue = drop-queue::DropQueue::new();
let app = notmad::Mad::new().add(queue);
app.run().await?;
Ok(())
}
```
This will process tasks until the cancellation token is triggered, e.g., via SIGINT.
---
## 🔒 Drain Mode
You can signal the queue to stop accepting new items and finish processing the current ones:
```rust
queue.drain().await?;
```
After this call, any further `assign()` will panic.
---
## 🧪 Tests
Run the test suite using:
```bash
cargo test
```
---
## 📜 License
MIT