luby/crates/lb/src/runtime.rs

116 lines
2.8 KiB
Rust

#![doc(hidden)]
use derive_more::{Deref, DerefMut};
use luaffi::{Module, Registry};
use luajit::{Chunk, State};
use std::rc::Rc;
use tokio::{
task::{JoinHandle, LocalSet, futures::TaskLocalFuture, spawn_local},
task_local,
};
pub type ErrorFn = dyn Fn(&luajit::Error);
pub struct Builder {
registry: Registry,
report_err: Rc<ErrorFn>,
}
impl Builder {
pub fn new() -> Self {
Self {
registry: Registry::new(),
report_err: Rc::new(|err| match err.trace() {
Some(trace) => eprintln!("unhandled lua error: {err}\n{trace}"),
None => eprintln!("unhandled lua error: {err}"),
}),
}
}
pub fn registry(&self) -> &Registry {
&self.registry
}
pub fn unhandled_error(&mut self, handler: impl Fn(&luajit::Error) + 'static) -> &mut Self {
self.report_err = Rc::new(handler);
self
}
pub fn module<T: Module>(&mut self) -> &mut Self {
self.registry.preload::<T>();
self
}
pub fn build(&self) -> luajit::Result<Runtime> {
Ok(Runtime {
cx: Context {
state: {
let mut s = State::new()?;
s.eval(Chunk::new(self.registry.build()).path("[luby]"), 0, 0)?;
s
},
report_err: self.report_err.clone(),
},
tasks: LocalSet::new(),
})
}
}
#[derive(Deref, DerefMut)]
pub struct Runtime {
#[deref]
#[deref_mut]
cx: Context,
tasks: LocalSet,
}
impl Runtime {
pub fn spawn<T: 'static>(
&self,
f: impl AsyncFnOnce(&mut Context) -> T + 'static,
) -> JoinHandle<T> {
self.tasks
.spawn_local(async move { f(&mut CURRENT.with(|s| s.new_thread())).await })
}
}
impl IntoFuture for Runtime {
type Output = ();
type IntoFuture = TaskLocalFuture<Context, LocalSet>;
fn into_future(self) -> Self::IntoFuture {
CURRENT.scope(self.cx, self.tasks)
}
}
task_local! {
static CURRENT: Context;
}
#[derive(Deref, DerefMut)]
pub struct Context {
#[deref]
#[deref_mut]
state: State,
report_err: Rc<ErrorFn>,
}
impl Context {
pub fn new_thread(&self) -> Self {
Self {
state: self.state.new_thread(),
report_err: self.report_err.clone(),
}
}
pub fn report_error(&self, err: &luajit::Error) {
(self.report_err)(&err);
}
}
pub fn spawn<T: 'static>(f: impl AsyncFnOnce(&mut Context) -> T + 'static) -> JoinHandle<T> {
// SAFETY: `new_thread` must be called inside `spawn_local` because this free-standing spawn
// function may be called via ffi from lua, and it is not safe to access the lua state within
// ffi calls.
spawn_local(async move { f(&mut CURRENT.with(|s| s.new_thread())).await })
}