A queued/downloading row previously showed the bare video id and no thumbnail because asset metadata was only filled when the download completed. Now: - service.populate_from_catalog fills title/uploader/thumbnail/date/duration at enqueue from our own Video/Channel catalog (0 network cost) — feed downloads look right instantly - worker fills the same from yt-dlp's info_dict on the first progress event (covers ad-hoc URLs / catalog misses), best-effort, never fails a download Verified: a paused feed download now shows its real title, channel, thumbnail and duration.
123 lines
4.4 KiB
Python
123 lines
4.4 KiB
Python
"""Enqueue + cache resolution for the download center (the per-user layer over MediaAsset).
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`enqueue` is the single entry point used by the API: it resolves (or creates) the shared
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MediaAsset for the requested source+format, links a per-user DownloadJob to it, and — on a
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cache hit (asset already ready) — marks the job done instantly with no re-download. The worker
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handles everything else. State transitions used by the routes (pause/resume/cancel/delete) and
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the worker live in `worker.py` / the routes; this module owns enqueue + asset bookkeeping.
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"""
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from datetime import datetime, timezone
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from sqlalchemy import func, select
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from sqlalchemy.exc import IntegrityError
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from sqlalchemy.orm import Session
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from app.downloads import formats, quota
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from app.models import Channel, DownloadJob, MediaAsset, Video
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def source_url(source_kind: str, source_ref: str) -> str:
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"""The URL yt-dlp should fetch. YouTube stores the 11-char id; ad-hoc stores the URL."""
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if source_kind == "youtube":
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return f"https://www.youtube.com/watch?v={source_ref}"
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return source_ref
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def get_or_create_asset(
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db: Session, source_kind: str, source_ref: str, format_sig: str
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) -> MediaAsset:
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"""Fetch the cache row for this (source, format) or create a fresh `pending` one.
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Races on the unique cache key are resolved by re-selecting after an IntegrityError, so two
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simultaneous enqueues of the same video+format converge on one shared asset."""
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stmt = select(MediaAsset).where(
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MediaAsset.source_kind == source_kind,
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MediaAsset.source_ref == source_ref,
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MediaAsset.format_sig == format_sig,
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)
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asset = db.execute(stmt).scalar_one_or_none()
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if asset is not None:
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return asset
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asset = MediaAsset(
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source_kind=source_kind,
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source_ref=source_ref,
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format_sig=format_sig,
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status="pending",
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ref_count=0,
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)
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db.add(asset)
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try:
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db.flush()
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except IntegrityError:
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db.rollback()
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asset = db.execute(stmt).scalar_one()
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return asset
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def populate_from_catalog(db: Session, asset: MediaAsset) -> bool:
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"""Fill an asset's display metadata (title/uploader/thumbnail/date/duration) from our own
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catalog when the source is a known YouTube video — so a queued/downloading row shows the
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real title + thumbnail immediately instead of the bare id. 0 network cost. Returns True if
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it found a catalog match."""
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if asset.source_kind != "youtube" or asset.title:
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return False
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video = db.get(Video, asset.source_ref)
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if video is None:
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return False
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asset.title = video.title
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asset.thumbnail_url = video.thumbnail_url
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asset.duration_s = video.duration_seconds
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if video.published_at:
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asset.upload_date = video.published_at.date()
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channel = db.get(Channel, video.channel_id)
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if channel is not None:
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asset.uploader = channel.title
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return True
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def _next_queue_pos(db: Session) -> int:
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return (db.execute(select(func.coalesce(func.max(DownloadJob.queue_pos), 0))).scalar() or 0) + 1
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def enqueue(
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db: Session,
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user_id: int,
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source_kind: str,
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source_ref: str,
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spec: dict,
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profile_id: int | None = None,
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display_name: str | None = None,
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) -> DownloadJob:
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"""Queue a download for `user_id`. Returns the DownloadJob (already `done` on a cache hit).
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Raises quota.QuotaExceeded if the user is at their job-count or footprint cap."""
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quota.check_enqueue(db, user_id)
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spec = formats.normalize(spec)
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sig = formats.format_sig(spec)
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asset = get_or_create_asset(db, source_kind, source_ref, sig)
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# Show a real title + thumbnail the moment it's queued (feed downloads are catalog videos).
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populate_from_catalog(db, asset)
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job = DownloadJob(
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user_id=user_id,
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asset_id=asset.id,
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source_kind=source_kind,
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source_ref=source_ref,
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profile_id=profile_id,
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profile_snapshot=spec,
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display_name=display_name or (asset.title if asset.status == "ready" else None),
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status="queued",
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queue_pos=_next_queue_pos(db),
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)
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db.add(job)
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asset.ref_count = (asset.ref_count or 0) + 1
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# Cache hit: the file already exists — no worker round-trip needed.
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if asset.status == "ready":
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job.status = "done"
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job.progress = 100
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asset.last_access_at = datetime.now(timezone.utc)
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db.commit()
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db.refresh(job)
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return job
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