Trait opendal::Execute

source ·

pub trait Execute: Send + Sync + 'static {
    // Required method
    fn execute(&self, f: BoxedStaticFuture<()>);

    // Provided method
    fn timeout(&self) -> Option<BoxedStaticFuture<()>> { ... }
}

Expand description

Execute trait is used to execute task in background.

§Notes about Timeout Implementation

Implementing a correct and elegant timeout mechanism is challenging for us.

The Execute trait must be object safe, allowing us to use Arc<dyn Execute>. Consequently, we cannot introduce a generic type parameter to Execute. We utilize [RemoteHandle] to implement the Execute::execute method. [RemoteHandle] operates by transmitting Future::Output through a channel, enabling the spawning of [BoxedStaticFuture<()>].

However, for timeouts, we need to spawn a future that resolves after a specified duration. Simply wrapping the future within another timeout future is not feasible because if the timeout is reached and the original future has not completed, it will be dropped—causing any held Task to panic.

As an alternative solution, we developed a timeout API. Users of the Executor should invoke this API when they require a timeout and combine it with their own futures using [futures::select].

This approach may seem inelegant but it allows us flexibility without being tied specifically to the Tokio runtime.

PLEASE raising an issue if you have a better solution.