| """The hourly cleanup of pictures, and deleting a student's pictures on request. `python -m mathly2.cleanup` runs it once; the server runs it |
| every hour when it is connected to Supabase.""" |
| from __future__ import annotations |
|
|
| import logging |
| import threading |
| from datetime import datetime |
|
|
| from . import clock, pictures, retention |
|
|
| log = logging.getLogger("mathly.cleanup") |
|
|
|
|
| def run(store, backend, now: datetime | None = None) -> dict: |
| """Remove pictures nothing refers to (after a day), answer pictures past their school year, and the pages of removed assignments. |
| Returns how many of each were removed. A picture whose bytes cannot be deleted now is left for the next run.""" |
| now = now or clock.now() |
| today = clock.school_day(now) |
| removed = {"orphans": 0, "expired": 0, "removed_assignments": 0} |
| for pic in store.pictures(): |
| refs = store.picture_refs(pic["id"]) |
| referenced = any(refs.values()) |
| if pic["kind"] in ("answer", "work") and retention.is_expired(clock.school_day(pic["created_at"]), today): |
| reason = "expired" |
| elif not referenced and now - pic["created_at"] > retention.ORPHAN_AGE: |
| reason = "orphans" |
| elif pic["kind"] == "page" and refs["assignments"] and all((store.get_assignment(a) or {}).get("removed_at") for a in refs["assignments"]): |
| reason = "removed_assignments" |
| else: |
| continue |
| try: |
| pictures.remove_picture(store, backend, pic, now) |
| removed[reason] += 1 |
| except pictures.PictureError as exc: |
| log.warning("could not delete a picture (%s); it stays for the next run", exc.code) |
| return removed |
|
|
|
|
| def delete_answer_pictures(store, backend, assignment_ids, user_id: str, now: datetime | None = None) -> int: |
| """Delete a student's answer pictures for these assignments now (a teacher of the class, a manager or a developer asked). The submissions |
| keep their grade and note. Returns how many pictures were deleted.""" |
| count = 0 |
| for sub in store.submissions_of_assignments(assignment_ids): |
| if sub["user_id"] != user_id: |
| continue |
| for pid in sub["pictures"]: |
| pic = store.get_picture(pid) |
| if pic and pic["kind"] == "answer" and pic["owner_id"] == user_id and not pic["deleted_at"]: |
| pictures.remove_picture(store, backend, pic, now) |
| count += 1 |
| return count |
|
|
|
|
| def start_hourly(store, backend, every: float = 3600.0) -> threading.Event: |
| """Run the cleanup now and then every `every` seconds in a background thread. Returns an event that stops it when set.""" |
| stop = threading.Event() |
|
|
| def loop() -> None: |
| while True: |
| try: |
| log.info("cleanup removed %s", run(store, backend)) |
| except Exception: |
| log.exception("the picture cleanup failed") |
| if stop.wait(every): |
| return |
|
|
| threading.Thread(target=loop, name="picture-cleanup", daemon=True).start() |
| return stop |
|
|
|
|
| def main() -> None: |
| from .config import load_settings |
| from .store import SupabaseStore |
| settings = load_settings() |
| if not settings.supabase_on: |
| raise SystemExit("Set the Supabase settings: the cleanup works on the real database.") |
| store = SupabaseStore(settings.supabase_url, settings.supabase_secret) |
| backend = pictures.SupabasePictures(settings.supabase_url, settings.supabase_secret, settings.answer_bucket) |
| print("Removed", run(store, backend)) |
|
|
|
|
| if __name__ == "__main__": |
| main() |
|
|
