CODEWITHSUNDEEP
rustrust-rocket
spicy-lemonade
spicy-lemonade

Reputation: 15

How can you access a rocket(rust) state at the end of the servers life?

I want to be able to do something with my state once the server starts shutting down

example:

struct MyConfig {
    user_val: String
}

#[get("/hello")]
fn hello(config: &State<MyConfig>) -> Result<String, error::Error> {
    //do stuff
    Ok(&config.user_val)
}

#[rocket::main]
async fn main() -> Result<(), error::Error> {
    let config = MyConfig{user_val: "hello".to_string()};
    let _rocket = rocket::build()
        .manage(config) //cant pass as borrow because it wont live long enough
        .mount("/", routes![hello])
        .launch()
        .await?;


    println!("{}", &config.user_val); //cant access because value moved

    Ok(())
}

The result should be when I shut down the program it prints user_val(I dont want to clone)

but after setting it as a state its no longer accessible after the server ends

Upvotes: 1

Views: 564

Answers (1)

kmdreko
kmdreko

Reputation: 60517

You can get access to the config by using .state() afterwards:

struct MyConfig {
    user_val: String,
}

#[rocket::main]
async fn main() -> Result<(), rocket::error::Error> {
    let config = MyConfig { user_val: "hello".to_string()};
    let rocket = rocket::build()
        .manage(config)
        .ignite() // this puts it in the post-launch state for testing
        .await?;

    let config = rocket.state::<MyConfig>().unwrap();

    println!("{}", config.user_val);

    Ok(())
}

hello

Although, config will be a reference. You aren't able to take ownership back after giving it to Rocket. If you need ownership, you'll have to .clone() the config or store it in an Arc before managing so you can .clone() that to avoid duplicating the underlying config data.

Upvotes: 2

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