feat(fc2a): add Celery tasks — scan_directory, import_media_file, generate_thumbnail

scan_directory walks ImportSettings.import_scan_path, creates an
ImportBatch, enumerates supported files into ImportTasks, and enqueues
import_media_file per task. import_media_file moves the task through
its state machine (pending → queued → processing → complete/skipped/failed),
updates ImportBatch counters atomically (UPDATE ... SET col = col + 1),
enqueues a thumbnail task on success, and marks the batch complete when
the last task drains.

generate_thumbnail runs on its own queue (thumbnail) so big imports
don't starve thumbnail throughput; failure here is logged and does not
fail the import.

Co-Authored-By: Claude Opus 4.7 (1M context) <noreply@anthropic.com>
This commit is contained in:
2026-05-14 12:08:37 -04:00
parent f38a1d48c5
commit d3bb8c509a
5 changed files with 272 additions and 1 deletions
+7 -1
View File
@@ -22,7 +22,13 @@ def make_celery() -> Celery:
"fabledcurator",
broker=cfg.celery_broker_url,
backend=cfg.celery_result_backend,
include=["backend.app.tasks.smoke"], # FC-2/FC-3 extend this list
include=[
"backend.app.tasks.smoke",
"backend.app.tasks.scan",
"backend.app.tasks.import_file",
"backend.app.tasks.thumbnail",
"backend.app.tasks.maintenance",
],
)
app.conf.update(
task_default_queue="default",
+122
View File
@@ -0,0 +1,122 @@
"""import_media_file task: imports one file via the Importer service and
updates the ImportTask state machine + ImportBatch counters atomically.
"""
from datetime import datetime, timezone
from pathlib import Path
from sqlalchemy import create_engine, select, update
from sqlalchemy.orm import sessionmaker
from ..celery_app import celery
from ..config import get_config
from ..models import ImportBatch, ImportSettings, ImportTask
from ..services.importer import Importer
from ..services.thumbnailer import Thumbnailer
def _sync_session_factory():
cfg = get_config()
engine = create_engine(cfg.database_url_sync, future=True, pool_pre_ping=True)
return sessionmaker(engine, expire_on_commit=False)
IMAGES_ROOT = Path("/images")
@celery.task(name="backend.app.tasks.import_file.import_media_file", bind=True)
def import_media_file(self, import_task_id: int) -> dict:
"""Returns a dict so the eager-mode tests can assert without DB."""
SessionLocal = _sync_session_factory()
with SessionLocal() as session:
task = session.get(ImportTask, import_task_id)
if task is None:
return {"status": "missing", "task_id": import_task_id}
task.status = "processing"
task.started_at = datetime.now(timezone.utc)
session.add(task)
session.commit()
settings = session.execute(
select(ImportSettings).where(ImportSettings.id == 1)
).scalar_one()
import_root = Path(settings.import_scan_path)
importer = Importer(
session=session,
images_root=IMAGES_ROOT,
import_root=import_root,
thumbnailer=Thumbnailer(images_root=IMAGES_ROOT),
settings=settings,
)
try:
result = importer.import_one(Path(task.source_path))
except Exception as exc: # pragma: no cover — pipeline crash
task.status = "failed"
task.error = f"{type(exc).__name__}: {exc}"
task.finished_at = datetime.now(timezone.utc)
session.execute(
update(ImportBatch)
.where(ImportBatch.id == task.batch_id)
.values(failed=ImportBatch.failed + 1)
)
session.add(task)
session.commit()
raise
if result.status == "imported":
task.status = "complete"
task.result_image_id = result.image_id
counter_col_name = "imported"
counter_col = ImportBatch.imported
elif result.status == "skipped":
task.status = "skipped"
task.error = (
f"{result.skip_reason.value}: {result.error}"
if result.skip_reason
else result.error
)
task.result_image_id = result.image_id
counter_col_name = "skipped"
counter_col = ImportBatch.skipped
else:
task.status = "failed"
task.error = result.error
counter_col_name = "failed"
counter_col = ImportBatch.failed
task.finished_at = datetime.now(timezone.utc)
session.execute(
update(ImportBatch)
.where(ImportBatch.id == task.batch_id)
.values({counter_col_name: counter_col + 1})
)
session.add(task)
session.commit()
# Enqueue the thumbnail task for newly imported images.
if result.status == "imported" and result.image_id is not None:
from .thumbnail import generate_thumbnail
generate_thumbnail.delay(result.image_id)
# If this was the last task in the batch, mark the batch complete.
remaining = session.execute(
select(ImportTask.id)
.where(ImportTask.batch_id == task.batch_id)
.where(ImportTask.status.in_(["pending", "queued", "processing"]))
.limit(1)
).scalar_one_or_none()
if remaining is None:
session.execute(
update(ImportBatch)
.where(ImportBatch.id == task.batch_id)
.values(
status="complete",
finished_at=datetime.now(timezone.utc),
)
)
session.commit()
return {"task_id": import_task_id, "status": task.status}
+78
View File
@@ -0,0 +1,78 @@
"""scan_directory task: walks the configured import path, creates an
ImportBatch, enumerates files into ImportTasks, and enqueues
import_media_file for each.
"""
from pathlib import Path
from sqlalchemy import create_engine, select
from sqlalchemy.orm import sessionmaker
from ..celery_app import celery
from ..config import get_config
from ..models import ImportBatch, ImportSettings, ImportTask
from ..services.importer import is_supported
def _sync_session_factory():
cfg = get_config()
engine = create_engine(cfg.database_url_sync, future=True, pool_pre_ping=True)
return sessionmaker(engine, expire_on_commit=False)
@celery.task(name="backend.app.tasks.scan.scan_directory", bind=True)
def scan_directory(self, triggered_by: str = "manual") -> int:
"""Walks the import root and creates ImportTasks. Returns the batch id."""
SessionLocal = _sync_session_factory()
with SessionLocal() as session:
settings = session.execute(
select(ImportSettings).where(ImportSettings.id == 1)
).scalar_one()
import_root = Path(settings.import_scan_path)
batch = ImportBatch(
triggered_by=triggered_by,
source_path=str(import_root),
scan_mode="quick", # FC-2a is quick only; FC-2d adds 'deep'
status="running",
)
session.add(batch)
session.flush()
batch_id = batch.id
# Walk and enumerate.
files_seen = 0
for entry in import_root.rglob("*"):
if not entry.is_file():
continue
if not is_supported(entry):
continue
try:
size = entry.stat().st_size
except OSError:
size = None
task = ImportTask(
batch_id=batch_id,
source_path=str(entry),
task_type="media",
status="pending",
size_bytes=size,
)
session.add(task)
files_seen += 1
batch.total_files = files_seen
session.commit()
# Now enqueue import_media_file for each pending task.
for task in session.execute(
select(ImportTask).where(ImportTask.batch_id == batch_id)
).scalars():
task.status = "queued"
session.add(task)
from .import_file import import_media_file
import_media_file.delay(task.id)
session.commit()
return batch_id
+50
View File
@@ -0,0 +1,50 @@
"""generate_thumbnail task: PIL/ffmpeg thumbnail generation on the thumbnail queue.
Lives separately from import_file because thumbnails can be regenerated en
masse (FC-2c adds the 'regenerate all' admin action) and they're CPU-bound
so they deserve their own queue lane.
"""
from pathlib import Path
from sqlalchemy import create_engine
from sqlalchemy.orm import sessionmaker
from ..celery_app import celery
from ..config import get_config
from ..models import ImageRecord
from ..services.importer import is_video
from ..services.thumbnailer import Thumbnailer
IMAGES_ROOT = Path("/images")
def _sync_session_factory():
cfg = get_config()
engine = create_engine(cfg.database_url_sync, future=True, pool_pre_ping=True)
return sessionmaker(engine, expire_on_commit=False)
@celery.task(name="backend.app.tasks.thumbnail.generate_thumbnail", bind=True)
def generate_thumbnail(self, image_id: int) -> dict:
SessionLocal = _sync_session_factory()
with SessionLocal() as session:
record = session.get(ImageRecord, image_id)
if record is None:
return {"status": "missing", "image_id": image_id}
thumbnailer = Thumbnailer(images_root=IMAGES_ROOT)
source = Path(record.path)
try:
if is_video(source):
result = thumbnailer.generate_video_thumbnail(source, record.sha256)
else:
result = thumbnailer.generate_image_thumbnail(source, record.sha256)
except Exception as exc: # pragma: no cover — thumbnail failure is non-fatal
return {"status": "failed", "image_id": image_id, "error": f"{type(exc).__name__}: {exc}"}
record.thumbnail_path = str(result.path)
session.add(record)
session.commit()
return {"status": "ok", "image_id": image_id, "path": str(result.path)}
+15
View File
@@ -0,0 +1,15 @@
"""Confirms every FC-2a task module imports cleanly and registers with Celery."""
from backend.app.celery_app import celery
def test_scan_task_registered():
assert "backend.app.tasks.scan.scan_directory" in celery.tasks
def test_import_media_file_registered():
assert "backend.app.tasks.import_file.import_media_file" in celery.tasks
def test_generate_thumbnail_registered():
assert "backend.app.tasks.thumbnail.generate_thumbnail" in celery.tasks