State Backends¶

#[async_trait]
pub trait StateStore: Send + Sync + 'static {
    async fn check_and_set(&self, key: &str, value: &str, ttl: Duration) -> Result<bool>;
    async fn get(&self, key: &str) -> Result<Option<String>>;
    async fn set(&self, key: &str, value: &str, ttl: Duration) -> Result<()>;
    async fn delete(&self, key: &str) -> Result<bool>;
    async fn increment(&self, key: &str, delta: i64, ttl: Duration) -> Result<i64>;
    async fn compare_and_swap(&self, key: &str, expected: u64, value: &str, ttl: Duration)
        -> Result<CasResult>;
    async fn scan_keys(&self, namespace: &str, tenant: &str, kind: &str, prefix: &str)
        -> Result<Vec<(String, String)>>;
    async fn scan_keys_by_kind(&self, kind: &str) -> Result<Vec<(String, String)>>;
    async fn index_timeout(&self, key: &str, expires_at_ms: i64) -> Result<()>;
    async fn remove_timeout_index(&self, key: &str) -> Result<()>;
    async fn get_expired_timeouts(&self, now_ms: i64) -> Result<Vec<String>>;
    async fn index_chain_ready(&self, key: &str, ready_at_ms: i64) -> Result<()>;
    async fn remove_chain_ready_index(&self, key: &str) -> Result<()>;
    async fn get_ready_chains(&self, now_ms: i64) -> Result<Vec<String>>;
}

#[async_trait]
pub trait DistributedLock: Send + Sync + 'static {
    async fn try_acquire(&self, name: &str, ttl: Duration) -> Result<Option<Box<dyn LockGuard>>>;
    async fn acquire(&self, name: &str, ttl: Duration, timeout: Duration)
        -> Result<Box<dyn LockGuard>>;
}

#[async_trait]
pub trait LockGuard: Send + Sync {
    async fn extend(&self, duration: Duration) -> Result<()>;
    async fn release(self: Box<Self>) -> Result<()>;
    async fn is_held(&self) -> Result<bool>;
}