Session back‑ends

MicroPie abstracts session storage behind the SessionBackend interface. Different back‑ends may store session data in memory, databases, caches or external services. A session is a dictionary of key/value pairs associated with a session_id cookie.

The application owns identifier generation and validation. Canonical UUIDv4 is the default; custom storage formats can be enabled with App(session_id_factory=..., session_id_validator=...). A storage back-end receives only IDs accepted by that policy.

SessionBackend

class SessionBackend

Abstract base class for session storage. Implementations must provide the following asynchronous methods:

load(session_id)

Load session data for the given session_id. Return a dictionary of session data or an empty dictionary if the session does not exist or has expired.

save(session_id, data, timeout)

Persist the data dictionary for the given session_id with an expiry time of timeout seconds.

InMemorySessionBackend

class InMemorySessionBackend

Concrete implementation of SessionBackend that stores sessions in memory. This back‑end is appropriate for development and testing but does not persist data across process restarts and cannot be shared among worker processes.

__init__()

Create an empty in‑memory session store.

load(session_id)

Return the session dictionary if it exists and has not expired according to the timeout supplied when it was saved, otherwise return an empty dictionary. Successful loads refresh the inactivity timer.

save(session_id, data, timeout)

Store data under session_id, retain timeout for that session, and update the last access time. Empty data or a non-positive timeout deletes the session.

SESSION_TIMEOUT

SESSION_TIMEOUT

The default session expiration time in seconds (eight hours). You can select a different value per application with App(session_timeout=...). The constant supplies the default; it is not consulted as mutable runtime policy by existing applications or saved in-memory sessions.

See also the Managing sessions guide for examples of using and implementing session back‑ends.