use async_trait::async_trait;
use executor_trait::{BlockingExecutor, Executor, FullExecutor, LocalExecutorError, Task};
use std::{
future::Future,
pin::Pin,
task::{Context, Poll},
};
#[derive(Debug, Default, Copy, Clone, PartialEq, Eq, PartialOrd, Ord)]
pub struct Smol;
struct STask(Option<smol::Task<()>>);
impl FullExecutor for Smol {}
impl Executor for Smol {
fn block_on(&self, f: Pin<Box<dyn Future<Output = ()>>>) {
smol::block_on(f);
}
fn spawn(&self, f: Pin<Box<dyn Future<Output = ()> + Send>>) -> Box<dyn Task> {
Box::new(STask(Some(smol::spawn(f))))
}
fn spawn_local(
&self,
f: Pin<Box<dyn Future<Output = ()>>>,
) -> Result<Box<dyn Task>, LocalExecutorError> {
Err(LocalExecutorError(f))
}
}
#[async_trait]
impl BlockingExecutor for Smol {
async fn spawn_blocking(&self, f: Box<dyn FnOnce() + Send + 'static>) {
smol::unblock(f).await;
}
}
#[async_trait(?Send)]
impl Task for STask {
async fn cancel(mut self: Box<Self>) -> Option<()> {
self.0.take()?.cancel().await
}
}
impl Drop for STask {
fn drop(&mut self) {
if let Some(task) = self.0.take() {
task.detach();
}
}
}
impl Future for STask {
type Output = ();
fn poll(mut self: Pin<&mut Self>, cx: &mut Context<'_>) -> Poll<Self::Output> {
Pin::new(self.0.as_mut().unwrap()).poll(cx)
}
}