1 2 3 4 5 6 7 8 9 10 11 12 13 14 15 16 17 18 19 20 21 22 23 24 25 26 27 28 29 30 31 32 33 34 35 36 37 38 39 40 41 42 43
pub(super) mod memory; use std::panic::RefUnwindSafe; use std::pin::Pin; use futures::prelude::*; use crate::middleware::session::{SessionError, SessionIdentifier}; /// A type which is used to spawn new `Backend` values. pub trait NewBackend: Sync + Clone + RefUnwindSafe { /// The type of `Backend` created by the `NewBackend`. type Instance: Backend + Send + 'static; /// Create and return a new `Backend` value. fn new_backend(&self) -> anyhow::Result<Self::Instance>; } /// Type alias for the trait objects returned by `Backend`. pub type SessionFuture = dyn Future<Output = Result<Option<Vec<u8>>, SessionError>> + Send; /// A `Backend` receives session data and stores it, and recalls the session data subsequently. /// /// All session data is serialized into a `Vec<u8>` which is treated as opaque by the backend. The /// serialization format is subject to change and must not be relied upon by the `Backend`. pub trait Backend: Send { /// Persists a session, either creating a new session or updating an existing session. fn persist_session( &self, identifier: SessionIdentifier, content: &[u8], ) -> Result<(), SessionError>; /// Retrieves a session from the underlying storage. /// /// The returned future will resolve to an `Option<Vec<u8>>` on success, where a value of /// `None` indicates that the session is not available for use and a new session should be /// established. fn read_session(&self, identifier: SessionIdentifier) -> Pin<Box<SessionFuture>>; /// Drops a session from the underlying storage. fn drop_session(&self, identifier: SessionIdentifier) -> Result<(), SessionError>; }