continuwuity/src/core/utils/mutex_map.rs
Jason Volk 2d251eb19c cleanup on drop for utils::mutex_map.
Signed-off-by: Jason Volk <jason@zemos.net>
2024-07-13 21:20:05 +00:00

79 lines
1.7 KiB
Rust

use std::{fmt::Debug, hash::Hash, sync::Arc};
use tokio::sync::OwnedMutexGuard as Omg;
/// Map of Mutexes
pub struct MutexMap<Key, Val> {
map: Map<Key, Val>,
}
pub struct Guard<Key, Val> {
map: Map<Key, Val>,
val: Omg<Val>,
}
type Map<Key, Val> = Arc<MapMutex<Key, Val>>;
type MapMutex<Key, Val> = std::sync::Mutex<HashMap<Key, Val>>;
type HashMap<Key, Val> = std::collections::HashMap<Key, Value<Val>>;
type Value<Val> = Arc<tokio::sync::Mutex<Val>>;
impl<Key, Val> MutexMap<Key, Val>
where
Key: Send + Hash + Eq + Clone,
Val: Send + Default,
{
#[must_use]
pub fn new() -> Self {
Self {
map: Map::new(MapMutex::new(HashMap::new())),
}
}
#[tracing::instrument(skip(self), level = "debug")]
pub async fn lock<K>(&self, k: &K) -> Guard<Key, Val>
where
K: ?Sized + Send + Sync + Debug,
Key: for<'a> From<&'a K>,
{
let val = self
.map
.lock()
.expect("locked")
.entry(k.into())
.or_default()
.clone();
Guard::<Key, Val> {
map: Arc::clone(&self.map),
val: val.lock_owned().await,
}
}
#[must_use]
pub fn contains(&self, k: &Key) -> bool { self.map.lock().expect("locked").contains_key(k) }
#[must_use]
pub fn is_empty(&self) -> bool { self.map.lock().expect("locked").is_empty() }
#[must_use]
pub fn len(&self) -> usize { self.map.lock().expect("locked").len() }
}
impl<Key, Val> Default for MutexMap<Key, Val>
where
Key: Send + Hash + Eq + Clone,
Val: Send + Default,
{
fn default() -> Self { Self::new() }
}
impl<Key, Val> Drop for Guard<Key, Val> {
fn drop(&mut self) {
if Arc::strong_count(Omg::mutex(&self.val)) <= 2 {
self.map
.lock()
.expect("locked")
.retain(|_, val| !Arc::ptr_eq(val, Omg::mutex(&self.val)) || Arc::strong_count(val) > 2);
}
}
}