Files
siftlode/backend/app/notifications.py
T
peter 83326ecf53 fix(downloads): clamp notification title to column limit so download_gc can't wedge
A downloaded FB/IG reel's "title" is the whole caption (up to ~1900 chars). It flowed
untrimmed into Notification.title (String(255)); at the batched download_gc commit that
raised psycopg StringDataRightTruncation in pass 1, aborting the whole run so expiry
deletion, LRU eviction and orphan reap never executed (13/110 prod assets already exceed
the limit). Clamp the title to 255 (with an ellipsis) centrally in create_notification —
defending all six callers — since the full title already reaches the client via `data`
and the column is only an English fallback. Add a regression test.
2026-08-16 19:24:51 +02:00

68 lines
2.5 KiB
Python

"""Helpers for the durable, server-backed per-user notification inbox (phase 1).
The inbox COEXISTS with the client-side transient "bell" (localStorage toasts): these rows
survive reloads/devices and are produced server-side. First producer is the maintenance
job. Unread rows never auto-expire; read rows are trimmed past a soft per-user cap so the
table can't grow without bound for a heavy user.
"""
from sqlalchemy import delete, select
from sqlalchemy.orm import Session
from app.models import Notification
# Keep at most this many READ notifications per user; older read ones are pruned. Unread
# rows are never pruned (the user hasn't seen them yet).
READ_SOFT_CAP = 200
# Hard limit of the Notification.title column (String(255)). Titles are only an English
# fallback — the client renders the translated message from `data` — so clamping an
# over-long one (e.g. a FB/IG reel whose "title" is the whole caption, hundreds of chars)
# is harmless to the UI and prevents a StringDataRightTruncation that would abort the
# caller's whole transaction (the batched download_gc run in particular).
TITLE_MAX_LEN = 255
def create_notification(
db: Session,
user_id: int,
type: str,
title: str,
body: str | None = None,
data: dict | None = None,
*,
commit: bool = True,
) -> Notification:
"""Insert one notification for a user. Callers that batch many inserts in a single
transaction can pass commit=False and commit once themselves."""
if title is not None and len(title) > TITLE_MAX_LEN:
title = title[: TITLE_MAX_LEN - 1] + "…" # clamp to the column limit, add an ellipsis
notif = Notification(
user_id=user_id, type=type, title=title, body=body, data=data
)
db.add(notif)
if commit:
db.commit()
db.refresh(notif)
return notif
def trim_read(db: Session, user_id: int, cap: int = READ_SOFT_CAP) -> int:
"""Delete a user's oldest READ notifications beyond `cap`. Returns the number removed.
Idempotent and cheap; safe to call after marking things read."""
ids = (
db.execute(
select(Notification.id)
.where(Notification.user_id == user_id, Notification.read.is_(True))
.order_by(Notification.created_at.desc())
.offset(cap)
)
.scalars()
.all()
)
if not ids:
return 0
# One bulk DELETE rather than a get+delete per row (the ids are already in hand).
db.execute(delete(Notification).where(Notification.id.in_(ids)))
db.commit()
return len(ids)