Function blocking 

pub fn blocking<F, R>(
    f: F,
) -> impl Fn() -> Pin<Box<dyn Future<Output = Response> + Send>> + Clone
where
    F: Fn() -> R + Send + Sync + Clone + 'static,
    R: IntoResponse + Send + 'static,

Wrap a synchronous (blocking) function as an Axum handler.

The function will be dispatched to Tokio’s blocking thread pool via tokio::task::spawn_blocking. This prevents CPU-bound work from starving the async executor.

Example

use vil_server_core::sync_handler::blocking;

// CPU-bound handler — runs on blocking thread pool
fn predict(body: Vec<u8>) -> String {
    // Heavy computation...
    format!("Processed {} bytes", body.len())
}

// Use in route:
// .route("/predict", post(blocking(predict)))