Convert your sync functions into non-blocking thread futures.
Support for both Futures 0.1 and Futures 0.3. By default, Futures 0.3 will be used.
This is just an example to illustrate when this library could be useful.
Imagine you're creating an actix-web API and you have and endpoint that has to execute a very long synchronous task.
Normally, most of the modern crates will provide some async variants but still there are some of them that only provide a sync implementation.
This could be problematic as this endpoint could block the main thread and avoid other endpoints from being executed.
Take a look at this code:
```rust use actix_web::{web, App, HttpServer, Responder}; use std::time::Duration;
async fn index_async() -> impl Responder { futures::future::ready("Hello world").await }
async fn indexasyncblocking() -> impl Responder { futures::future::lazy(|| { std::thread::sleep(Duration::fromsecs(5)); "Hello blocking world" }) .await }
fn main() -> std::io::Result<()> { HttpServer::new(|| { App::new() .route("/", web::get().toasync(indexasync)) .route("/blocking", web::get().toasync(indexasync_blocking)) }) .workers(1) .bind("localhost:8080")? .run() } ```
If you try to get localhost:8080/blocking and then get localhost:8080, you will be able to see that you won't get any response until the blocking endpoint has returned.
With just a slight change we could get rid of this issue:
```rust async fn indexasyncnonblocking() -> impl Responder { futurify::wrap(|| { std::thread::sleep(Duration::fromsecs(5)); "Hello non blocking world" }) }
fn main() -> std::io::Result<()> { HttpServer::new(|| { App::new() .route("/", web::get().to(indexasync)) .route("/blocking", web::get().to(indexasyncblocking)) .route("/non-blocking", web::get().to(indexasyncnonblocking)) }) .workers(1) .bind("localhost:8080")? .run() } ````
Just wrap a closure with futurify::wrap and you'll get a futures 0.3 future ready to be polled.
If you need support for Futures 0.1 just import the library like this in your Cargo.toml:
toml
futurify = { version = "0.3", features = "futures_01", default-features = false }
That should do the trick!