siftlode/backend/app/downloads/service.py
npeter83 7f9847c2c2 fix(downloads): add the downloads package (was wrongly gitignored) + robust sanitizer
The .gitignore 'downloads/' pattern for the DOWNLOAD_ROOT bind mount also matched the
backend/app/downloads source package, so formats.py/storage.py/service.py never got
committed with M2. Anchor the ignore to '/downloads/' (repo root only) and add the package.

storage.sanitize() now handles arbitrarily messy titles (emoji, ZWJ, fullwidth, clickbait
punctuation): NFKC-normalize, drop emoji/symbol/control unicode categories, collapse
repeated punctuation, underscore-join words -> space-free paths. Accents (HU/DE) preserved,
no ASCII folding. Plex layout uses _-_ separators + Season_{year}.
2026-07-03 00:19:22 +02:00

97 lines
3.3 KiB
Python

"""Enqueue + cache resolution for the download center (the per-user layer over MediaAsset).
`enqueue` is the single entry point used by the API: it resolves (or creates) the shared
MediaAsset for the requested source+format, links a per-user DownloadJob to it, and — on a
cache hit (asset already ready) — marks the job done instantly with no re-download. The worker
handles everything else. State transitions used by the routes (pause/resume/cancel/delete) and
the worker live in `worker.py` / the routes; this module owns enqueue + asset bookkeeping.
"""
from datetime import datetime, timezone
from sqlalchemy import func, select
from sqlalchemy.exc import IntegrityError
from sqlalchemy.orm import Session
from app.downloads import formats
from app.models import DownloadJob, MediaAsset
def source_url(source_kind: str, source_ref: str) -> str:
"""The URL yt-dlp should fetch. YouTube stores the 11-char id; ad-hoc stores the URL."""
if source_kind == "youtube":
return f"https://www.youtube.com/watch?v={source_ref}"
return source_ref
def get_or_create_asset(
db: Session, source_kind: str, source_ref: str, format_sig: str
) -> MediaAsset:
"""Fetch the cache row for this (source, format) or create a fresh `pending` one.
Races on the unique cache key are resolved by re-selecting after an IntegrityError, so two
simultaneous enqueues of the same video+format converge on one shared asset."""
stmt = select(MediaAsset).where(
MediaAsset.source_kind == source_kind,
MediaAsset.source_ref == source_ref,
MediaAsset.format_sig == format_sig,
)
asset = db.execute(stmt).scalar_one_or_none()
if asset is not None:
return asset
asset = MediaAsset(
source_kind=source_kind,
source_ref=source_ref,
format_sig=format_sig,
status="pending",
ref_count=0,
)
db.add(asset)
try:
db.flush()
except IntegrityError:
db.rollback()
asset = db.execute(stmt).scalar_one()
return asset
def _next_queue_pos(db: Session) -> int:
return (db.execute(select(func.coalesce(func.max(DownloadJob.queue_pos), 0))).scalar() or 0) + 1
def enqueue(
db: Session,
user_id: int,
source_kind: str,
source_ref: str,
spec: dict,
profile_id: int | None = None,
display_name: str | None = None,
) -> DownloadJob:
"""Queue a download for `user_id`. Returns the DownloadJob (already `done` on a cache hit)."""
spec = formats.normalize(spec)
sig = formats.format_sig(spec)
asset = get_or_create_asset(db, source_kind, source_ref, sig)
job = DownloadJob(
user_id=user_id,
asset_id=asset.id,
source_kind=source_kind,
source_ref=source_ref,
profile_id=profile_id,
profile_snapshot=spec,
display_name=display_name or (asset.title if asset.status == "ready" else None),
status="queued",
queue_pos=_next_queue_pos(db),
)
db.add(job)
asset.ref_count = (asset.ref_count or 0) + 1
# Cache hit: the file already exists — no worker round-trip needed.
if asset.status == "ready":
job.status = "done"
job.progress = 100
asset.last_access_at = datetime.now(timezone.utc)
db.commit()
db.refresh(job)
return job