linnet/app/models/session.py
pyr0ball 1bc47b8e0f fix: mobile tab timeout — idle session reaper + wake lock + visibility reconnect
Backend:
- Session.last_subscriber_left_at: monotonic timestamp set when last SSE subscriber
  leaves, cleared when a new one arrives
- Session.subscriber_count(): replaces len(_subscribers) access from outside the model
- session_store._reaper_loop(): kills sessions with no subscribers for >SESSION_IDLE_TTL_S
  (default 90s); runs every TTL/2 seconds via asyncio.create_task at startup
- session_store._reaper_loop_once(): single-cycle variant for deterministic tests
- app/main.py lifespan: starts reaper on startup, cancels it cleanly on shutdown
- config.py: SESSION_IDLE_TTL_S setting (90s default, overridable per-env)

Frontend:
- useWakeLock.ts: Screen Wake Lock API wrapper; acquires on connect, releases on
  disconnect; degrades silently when unsupported (battery saver, iOS Safari)
- useToneStream.ts: visibilitychange handler — on hidden: closes EventSource without
  ending backend session (grace window stays open); on visible: GET /session/{id}
  liveness check, reconnects SSE + re-acquires wake lock if alive, sets expired=true
  and calls store.reset() if reaped
- ComposeBar.vue: surfaces expired state with calm 'Session timed out' notice
  (not an error — expected behaviour on long screen-off)

Tests:
- test_reaper.py: 7 tests covering subscriber idle tracking, reaper eligibility
  (kills idle, spares active subscriber, spares within-TTL)
2026-04-11 09:42:42 -07:00

84 lines
2.9 KiB
Python

# app/models/session.py — Session dataclass
from __future__ import annotations
import asyncio
import time
import uuid
from dataclasses import dataclass, field
from typing import Literal, Protocol, runtime_checkable
from app.models.tone_event import ToneEvent
SessionState = Literal["starting", "running", "stopped"]
@runtime_checkable
class SessionEvent(Protocol):
"""Any event that can be broadcast over SSE from a session."""
def to_sse(self) -> str: ...
@dataclass
class Session:
"""
An active annotation session.
The session owns the subscriber queue fan-out: each SSE connection
subscribes by calling subscribe() and gets its own asyncio.Queue.
The session_store fans out ToneEvents to all queues via broadcast().
"""
session_id: str = field(default_factory=lambda: str(uuid.uuid4())[:8])
state: SessionState = "starting"
created_at: float = field(default_factory=time.monotonic)
elcor: bool = False
# cf-voice sidecar — populated by session_store._allocate_voice() when cf-orch
# is configured. Empty string means in-process fallback is active.
cf_voice_url: str = ""
cf_voice_allocation_id: str = ""
# History: last 50 events retained for GET /session/{id}/history
history: list[ToneEvent] = field(default_factory=list)
_subscribers: list[asyncio.Queue] = field(default_factory=list, repr=False)
# Idle tracking: monotonic timestamp of when the last subscriber left.
# None means at least one subscriber is currently active, or the session
# has never had one yet (just started). The reaper uses this to detect
# abandoned sessions after a mobile tab timeout.
last_subscriber_left_at: float | None = field(default=None, repr=False)
def subscriber_count(self) -> int:
return len(self._subscribers)
def subscribe(self) -> asyncio.Queue:
"""Add an SSE subscriber. Returns its dedicated queue."""
q: asyncio.Queue = asyncio.Queue(maxsize=100)
self._subscribers.append(q)
# Reset idle clock — someone is watching again
self.last_subscriber_left_at = None
return q
def unsubscribe(self, q: asyncio.Queue) -> None:
try:
self._subscribers.remove(q)
except ValueError:
pass
# Start the idle clock when the last subscriber leaves
if not self._subscribers:
self.last_subscriber_left_at = time.monotonic()
def broadcast(self, event: SessionEvent) -> None:
"""Fan out any SessionEvent (tone, speaker, etc.) to all SSE subscribers."""
if isinstance(event, ToneEvent):
if len(self.history) >= 50:
self.history.pop(0)
self.history.append(event)
dead: list[asyncio.Queue] = []
for q in self._subscribers:
try:
q.put_nowait(event)
except asyncio.QueueFull:
dead.append(q)
for q in dead:
self.unsubscribe(q)