Files
siftlode/backend/app/downloads/backfill.py
T
peter 8e4dee1bb6 refactor(downloads): introduce SourceAdapter — a thin per-source Strategy over yt-dlp
Consolidates source-specific policy (youtube / facebook / reddit / generic) that was scattered
across worker.py, backfill.py, service.py, formats.py and storage.py with no shared source
identity. app/downloads/adapters.py holds the base (= generic yt-dlp behaviour) + per-source
overrides; resolve_adapter(source_kind, source_ref, info) picks one by source_kind, the yt-dlp
extractor_key, or the URL host, falling back to generic. yt-dlp stays the engine — the adapter is
policy only.

Moved into adapters (behaviour-equivalent):
- uploader_url derivation (YouTube channel_url / Facebook uploader_id / reddit None) — removes the
  worker/backfill duplication (build_uploader_url + _should_refetch gone).
- the player-client fallback sets + retriable markers + YouTube extractor_args/POT (build_ydl_opts
  now takes source-agnostic opts plus an `extra` dict from the adapter).
- source_url reconstruction (service.source_url delegates to the adapter).

Two intentional (approved) behaviour changes:
- the player-client fallback is now YouTube-only; non-YouTube sources make a single extraction
  attempt instead of a pointless double attempt with youtube-only client args.
- the .nfo <uniqueid type=...> follows the source (adapter.nfo_uniqueid_type) instead of the
  hardcoded "youtube" that mislabelled every url-source download.

Deliberately left generic (documented non-moves): title cleaning (normalize_title is harmless
across sources), the classify marker table, thumbnail_to_jpg, the format selectors, and og.py's
YouTube-hqdefault og:image preference (a self-contained thumbnail heuristic on the share path).

Verified end-to-end on localdev across all four adapters: downloads succeed and uploader_url + the
.nfo uniqueid type are correct per source.
2026-08-13 00:34:42 +02:00

84 lines
3.4 KiB
Python

"""One-off backfill for downloads made before per-asset channel URLs + poster fallbacks existed.
Fills `media_assets.uploader_url` (re-extracting metadata for YouTube/Facebook sources, so an
auto-detected channel becomes a clickable link) and `poster_path` (an ffmpeg frame for
thumbnail-less sources, so the card / watch page / link preview still shows an image). Best-effort
and safe to re-run: it only touches assets still missing the field, and only re-fetches YouTube /
Facebook sources (a direct media URL like a reddit HLS manifest carries no channel and its signed
URL may have expired — those just get a locally-generated poster instead).
Run once per environment:
docker exec siftlode-worker-1 python -c "from app.downloads import backfill; print(backfill.run())"
"""
import logging
import yt_dlp
from sqlalchemy import select
from app.config import settings
from app.db import SessionLocal
from app.downloads import adapters
from app.downloads import edit as editmod
from app.downloads import formats, service
from app.models import MediaAsset
log = logging.getLogger("siftlode.backfill")
def _extract_meta(url: str, adapter: adapters.SourceAdapter) -> dict | None:
"""Metadata-only yt-dlp extraction, using the source adapter's client sets + options (YouTube
needs the POT/player-client strategy even just to extract)."""
for clients in adapter.client_sets():
opts = formats.build_ydl_opts(
{}, "%(id)s.%(ext)s", lambda d: None, extra=adapter.ydl_opts_extra(clients)
)
opts["skip_download"] = True
try:
with yt_dlp.YoutubeDL(opts) as ydl:
info = ydl.extract_info(url, download=False)
if info:
return info
except Exception as exc: # noqa: BLE001 — best-effort backfill, keep going
log.info("meta extract failed for %s (%s): %s", url, clients, str(exc)[:100])
return None
def run() -> dict:
filled_url = filled_poster = 0
with SessionLocal() as db:
assets = (
db.execute(
select(MediaAsset).where(
MediaAsset.status == "ready", MediaAsset.rel_path.is_not(None)
)
)
.scalars()
.all()
)
for a in assets:
adapter = adapters.resolve_adapter(a.source_kind, a.source_ref)
if a.uploader_url is None and adapter.wants_metadata_backfill():
url = a.source_webpage_url or service.source_url(a.source_kind, a.source_ref)
info = _extract_meta(url, adapter)
uu = adapter.uploader_url(info) if info else None
if uu:
a.uploader_url = uu
filled_url += 1
log.info("asset %s uploader_url <- %s", a.id, uu)
if a.poster_path is None:
# Record a self-hosted poster for every download (the reliable og:image source):
# ensure_poster returns the existing <base>.jpg thumbnail sidecar, or cuts a frame.
rel = editmod.ensure_poster(a, settings.download_root)
if rel:
a.poster_path = rel
filled_poster += 1
log.info("asset %s poster <- %s", a.id, rel)
db.commit()
result = {
"assets": len(assets),
"filled_uploader_url": filled_url,
"filled_poster": filled_poster,
}
log.info("backfill done: %s", result)
return result