55 lines
1.5 KiB
Rust
55 lines
1.5 KiB
Rust
use std::{
|
|
collections::{hash_map, HashMap},
|
|
future::Future,
|
|
pin::Pin,
|
|
sync::RwLock,
|
|
};
|
|
use tokio::sync::watch;
|
|
|
|
#[derive(Default)]
|
|
pub(super) struct Watchers {
|
|
#[allow(clippy::type_complexity)]
|
|
watchers: RwLock<HashMap<Vec<u8>, (watch::Sender<()>, watch::Receiver<()>)>>,
|
|
}
|
|
|
|
impl Watchers {
|
|
pub(super) fn watch<'a>(
|
|
&'a self,
|
|
prefix: &[u8],
|
|
) -> Pin<Box<dyn Future<Output = ()> + Send + 'a>> {
|
|
let mut rx = match self.watchers.write().unwrap().entry(prefix.to_vec()) {
|
|
hash_map::Entry::Occupied(o) => o.get().1.clone(),
|
|
hash_map::Entry::Vacant(v) => {
|
|
let (tx, rx) = tokio::sync::watch::channel(());
|
|
v.insert((tx, rx.clone()));
|
|
rx
|
|
}
|
|
};
|
|
|
|
Box::pin(async move {
|
|
// Tx is never destroyed
|
|
rx.changed().await.unwrap();
|
|
})
|
|
}
|
|
pub(super) fn wake(&self, key: &[u8]) {
|
|
let watchers = self.watchers.read().unwrap();
|
|
let mut triggered = Vec::new();
|
|
|
|
for length in 0..=key.len() {
|
|
if watchers.contains_key(&key[..length]) {
|
|
triggered.push(&key[..length]);
|
|
}
|
|
}
|
|
|
|
drop(watchers);
|
|
|
|
if !triggered.is_empty() {
|
|
let mut watchers = self.watchers.write().unwrap();
|
|
for prefix in triggered {
|
|
if let Some(tx) = watchers.remove(prefix) {
|
|
let _ = tx.0.send(());
|
|
}
|
|
}
|
|
};
|
|
}
|
|
}
|