garage/src/model/k2v/poll.rs

51 lines
1.2 KiB
Rust

use std::collections::HashMap;
use std::sync::Mutex;
use serde::{Deserialize, Serialize};
use tokio::sync::broadcast;
use crate::k2v::item_table::*;
#[derive(Debug, Hash, Clone, PartialEq, Eq, Serialize, Deserialize)]
pub struct PollKey {
pub partition: K2VItemPartition,
pub sort_key: String,
}
#[derive(Default)]
pub struct SubscriptionManager {
subscriptions: Mutex<HashMap<PollKey, broadcast::Sender<K2VItem>>>,
}
impl SubscriptionManager {
pub fn new() -> Self {
Self::default()
}
pub fn subscribe(&self, key: &PollKey) -> broadcast::Receiver<K2VItem> {
let mut subs = self.subscriptions.lock().unwrap();
if let Some(s) = subs.get(key) {
s.subscribe()
} else {
let (tx, rx) = broadcast::channel(8);
subs.insert(key.clone(), tx);
rx
}
}
pub fn notify(&self, item: &K2VItem) {
let key = PollKey {
partition: item.partition.clone(),
sort_key: item.sort_key.clone(),
};
let mut subs = self.subscriptions.lock().unwrap();
if let Some(s) = subs.get(&key) {
if s.send(item.clone()).is_err() {
// no more subscribers, remove channel from here
// (we will re-create it later if we need to subscribe again)
subs.remove(&key);
}
}
}
}