use o3::depot::{arena::linked::slots, queue::pool};
use pool::Front;
use crate::link::event;
pub enum Push<'a, 'd, T = event::Completion<'d>> {
Ready {
vacant: slots::Vacant<event::Completion<'d>, slots::Bound<'a, event::Completion<'d>>>,
done: T,
},
Full(T),
}
pub trait Ops<'d> {
fn prepare_pop(&mut self) -> Option<Front<'_, event::Completion<'d>, ()>>;
fn has_queued(&self) -> bool;
}
pub trait Write<'d>: Ops<'d> {
fn prepare_push<T>(&mut self, done: T) -> Push<'_, 'd, T>;
}
impl<'d> Ops<'d> for &mut () {
fn prepare_pop(&mut self) -> Option<Front<'_, event::Completion<'d>, ()>> {
None
}
fn has_queued(&self) -> bool {
false
}
}
impl<'d> Ops<'d> for pool::Lane<'_, event::Completion<'d>> {
fn prepare_pop(&mut self) -> Option<Front<'_, event::Completion<'d>, ()>> {
self.front_mut()
}
fn has_queued(&self) -> bool {
!self.is_empty()
}
}
impl<'d> Write<'d> for pool::Lane<'_, event::Completion<'d>> {
fn prepare_push<T>(&mut self, done: T) -> Push<'_, 'd, T> {
match self.vacant() {
Some(vacant) => Push::Ready { vacant, done },
None => Push::Full(done),
}
}
}