meli/melib/src/async.rs

85 lines
1.9 KiB
Rust

use chan;
use std::thread;
#[derive(Debug)]
pub enum AsyncStatus {
NoUpdate,
Finished,
ProgressReport(usize),
}
#[derive(Debug)]
pub struct AsyncBuilder {
tx: chan::Sender<AsyncStatus>,
rx: chan::Receiver<AsyncStatus>,
}
#[derive(Debug)]
pub struct Async<T> {
value: Option<T>,
worker: Option<thread::JoinHandle<T>>,
tx: chan::Sender<AsyncStatus>,
rx: chan::Receiver<AsyncStatus>,
}
impl AsyncBuilder {
pub fn new() -> Self {
let (sender, receiver) = chan::sync(::std::mem::size_of::<AsyncStatus>());
AsyncBuilder {
tx: sender,
rx: receiver,
}
}
pub fn tx(&mut self) -> chan::Sender<AsyncStatus> {
self.tx.clone()
}
pub fn rx(&mut self) -> chan::Receiver<AsyncStatus> {
self.rx.clone()
}
pub fn build<T: Clone>(self, worker: thread::JoinHandle<T>) -> Async<T> {
Async {
worker: Some(worker),
value: None,
tx: self.tx,
rx: self.rx,
}
}
}
impl<T> Async<T> {
pub fn extract(self) -> T {
self.value.unwrap()
}
pub fn poll(&mut self) -> Result<AsyncStatus, ()> {
if self.value.is_some() {
return Ok(AsyncStatus::Finished);
}
//self.tx.send(true);
let rx = &self.rx;
chan_select! {
default => {
return Ok(AsyncStatus::NoUpdate);
},
rx.recv() -> r => {
match r {
Some(AsyncStatus::Finished) => {
},
Some(a) => {
return Ok(a);
}
_ => {
return Err(());
},
}
},
}
let v = self.worker.take().unwrap().join().unwrap();
self.value = Some(v);
return Ok(AsyncStatus::Finished);
}
}