Shared via Rust Playground

playground.rs

use std::sync::{Arc, RwLock};
use std::collections::HashMap;
use std::hash::Hash;
use std::cmp::Eq;

trait SessionStore<K, V> {
    fn remove(&self, key: &K) -> bool;
}

type Store<K, V> = RwLock<HashMap<K, RwLock<V>>>;

pub struct HashSessionStore<K, V>{
    store: Arc<Store<K, V>>
}

impl<K: Clone + Send, V: Send> Clone for HashSessionStore<K, V> {
    fn clone(&self) -> HashSessionStore<K, V> {
        HashSessionStore {
            store: self.store.clone()
        }
    }
}

impl<K: Hash + Eq + Send + Sync, V: Send + Sync> HashSessionStore<K, V> {
    /// Create a new instance of the session store
    pub fn new() -> HashSessionStore<K, V> {
        HashSessionStore {
            store: Arc::new(RwLock::new(HashMap::<K, RwLock<V>>::new()))
        }
    }
}

impl<K: Hash + Eq + Send + Sync + Clone, V: Send + Sync + Clone> SessionStore<K, V> for HashSessionStore<K, V> {
    fn remove(&self, key: &K) -> bool {
        self.store.write().unwrap().remove(key).is_some()
    }
}

fn main() {}