Module session_store

A session backend for managing session state.

This crate provides the ability to use custom backends for session management by implementing the SessionStore trait. This trait defines the necessary operations for creating, saving, loading, and deleting session records.

Implementing a Custom Store

Below is an example of implementing a custom session store using an in-memory [HashMap]. This example is for illustration purposes only; you can use the provided [MemoryStore] directly without implementing it yourself.

use std::{collections::HashMap, sync::Arc};

use async_trait::async_trait;
use time::OffsetDateTime;
use tokio::sync::Mutex;
use tower_sessions_core::{
    session::{Id, Record},
    session_store, SessionStore,
};

#[derive(Clone, Debug, Default)]
pub struct MemoryStore(Arc<Mutex<HashMap<Id, Record>>>);

#[async_trait]
impl SessionStore for MemoryStore {
    async fn create(&self, record: &mut Record) -> session_store::Result<()> {
        let mut store_guard = self.0.lock().await;
        while store_guard.contains_key(&record.id) {
            // Session ID collision mitigation.
            record.id = Id::default();
        }
        store_guard.insert(record.id, record.clone());
        Ok(())
    }

    async fn save(&self, record: &Record) -> session_store::Result<()> {
        self.0.lock().await.insert(record.id, record.clone());
        Ok(())
    }

    async fn load(&self, session_id: &Id) -> session_store::Result<Option<Record>> {
        Ok(self
            .0
            .lock()
            .await
            .get(session_id)
            .filter(|Record { expiry_date, .. }| is_active(*expiry_date))
            .cloned())
    }

    async fn delete(&self, session_id: &Id) -> session_store::Result<()> {
        self.0.lock().await.remove(session_id);
        Ok(())
    }
}

fn is_active(expiry_date: OffsetDateTime) -> bool {
    expiry_date > OffsetDateTime::now_utc()
}

Session Store Trait

The SessionStore trait defines the interface for session management. Implementations must handle session creation, saving, loading, and deletion.

CachingSessionStore

The CachingSessionStore provides a layered caching mechanism with a cache as the frontend and a store as the backend. This can improve read performance by reducing the need to access the backend store for frequently accessed sessions.

ExpiredDeletion

The ExpiredDeletion trait provides a method for deleting expired sessions. Implementations can optionally provide a method for continuously deleting expired sessions at a specified interval.

Structs

CachingSessionStore

Provides a layered caching mechanism with a cache as the frontend and a store as the backend..

Enums

Error

Stores must map any errors that might occur during their use to this type.

Traits

ExpiredDeletion

Provides a method for deleting expired sessions.

SessionStore

Defines the interface for session management.

Type Aliases

Result