peter
367bcebc9f
The cancel route writes status 'canceled' but the supervisor compared against 'cancelled', so its "a route stopped it -> kill the child, free the asset" branch was dead code. A canceled job's child ran to completion and wrote 'done' unconditionally over the route's 'canceled'; since 'done' holds the asset but 'canceled' does not, a later delete released the asset a second time, dropping ref_count below the live holder count and deleting a file still in use. Add app/downloads/status.py as the single source of truth for the lifecycle literals (JobStatus StrEnum + the HOLDING / STOPPED_BY_ROUTE sets) and use it at the safety-critical sites: the supervisor stop check, the route cancel, and release_asset's holding set. Make the worker's terminal done/error writes conditional on the row still being 'running' so a child finishing just after a route cancel/pause can no longer resurrect it. Add the missing 'canceled' supervisor regression test. (The full literal sweep across the downloads surface is left for the E3 downloads owner-unification; this is the data-safety subset.)
39 lines
2.1 KiB
Python
39 lines
2.1 KiB
Python
"""Canonical download-job status values — the ONE source of truth for the lifecycle literals.
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A job's status is written from several places: the worker (claim → running, terminal done/error,
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requeue), the routes (pause/cancel/redownload/delete), the service (enqueue), and the GC. Keeping the
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literals here is a data-safety measure, not tidiness. A British/American drift once silently broke
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cancellation: the supervisor compared the live status against ``"cancelled"`` while the cancel route
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wrote ``"canceled"`` (models.py), so the supervisor's "a route stopped it → kill the child, free the
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asset" branch was DEAD. A canceled job's child then ran to completion and wrote ``"done"``
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unconditionally over the route's ``"canceled"``; because ``done`` counts as a holding state but
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``canceled`` does not (see ``service.release_asset``), a later delete released the asset a SECOND time,
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dropping ``ref_count`` below the live holder count and deleting a file still in use. Import these names
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instead of typing the strings.
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"""
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from enum import StrEnum
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class JobStatus(StrEnum):
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QUEUED = "queued"
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RUNNING = "running"
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PAUSED = "paused"
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DONE = "done"
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ERROR = "error"
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CANCELED = "canceled"
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# A job "holds" its media asset (the +1 on ``ref_count`` from enqueue) while in any of these states;
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# ``release_asset`` on a status OUTSIDE this set is a no-op. ``CANCELED`` is deliberately excluded: the
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# cancel route releases once while the job is still holding, then sets ``CANCELED``, so a later delete
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# does not double-release. This invariant only holds while a finishing child cannot flip ``CANCELED``
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# back into the set — hence the worker's terminal writes are conditional on the row still being RUNNING.
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HOLDING = frozenset(
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{JobStatus.QUEUED, JobStatus.RUNNING, JobStatus.PAUSED, JobStatus.DONE, JobStatus.ERROR}
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)
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# States a route sets to STOP a running job. The worker's supervisor must step in (kill the child, free
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# the asset, leave the route's status intact) when it observes one of these on a job it is running.
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STOPPED_BY_ROUTE = frozenset({JobStatus.PAUSED, JobStatus.CANCELED})
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