Stage 5. A /media cache hit no longer touches SQLite: it records the access
timestamp into a module-level accumulator (a dict write on the event loop,
cheap and atomic), and a supervised 60s background task flushes the whole
batch in one executemany UPDATE. This removes both per-hit write sites — the
awaited to_thread in download_media_file and the fire-and-forget create_task
in the pre-semaphore fast path — so under active RSS polling the threadpool is
no longer starved by per-request access-time UPDATEs.
- file_io: add update_media_file_access_bulk_sync (one connection, executemany;
empty batch is a no-op).
- api_server: _access_updates accumulator + _flush_access_updates (snapshot-
then-clear atomically before the await so writes during the flush land in the
fresh dict; re-queue the batch with setdefault on write failure so a fresher
concurrent write is never clobbered and no access-time is lost) +
_access_flush_loop under _supervised + a final flush on shutdown, ordered
after the loop task is cancelled and before the io threadpool is shut down.
- Keys use str(channel) to match the TEXT channel column (a str/int mix would
make the UPDATE WHERE silently never match, evicting still-used files).
- tests/test_stage5_sqlite.py: 7 tests (no-sync-write hot path, str-key
discipline, hit->flush->DB, empty no-op, snapshot-then-clear race, re-queue-
without-clobbering-fresh, bulk SQL).
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
agent_coder
a04588740b