maziggy 64f9d04c80 fix(queue): claim a queue item before dispatch so it can't be reassigned mid-upload (#2615) ...

A queue row stays status='pending' for the whole FTP upload; status only flips
to 'printing' at the end. The edit routes only blocked non-pending rows, so a
PATCH during the upload window was accepted while the in-flight dispatch kept
using its snapshotted printer -- splitting the queue row from the archive /
expected-print / physical command across two printers, and enabling a duplicate
dispatch on restart. The #1853 CAS guards cancellation, not reassignment.

Add a dispatching_at claim, stamped atomically (WHERE status='pending' AND
dispatching_at IS NULL) before any slow I/O and cleared on every exit. While
held, the single-item PATCH returns 409 (re-checked just before the write),
bulk edits skip the row, and the scheduler won't re-select it. Startup
reconciliation clears claims orphaned by a crash mid-dispatch. The row stays
pending throughout, so no status/UI/completion/reconciliation path changes.

New column print_queue.dispatching_at (nullable, dialect-safe DDL). Covered by
scheduler tests (claim exclusivity, non-pending rejection, release-on-exit,
skip-already-claimed, startup stale-clear) and API tests (reassign 409,
printer_id unchanged, bulk skip, unclaimed row still edits).

2026-07-20 12:30:39 +02:00

..

app

fix(queue): claim a queue item before dispatch so it can't be reassigned mid-upload (#2615)

2026-07-20 12:30:39 +02:00

tests

fix(queue): claim a queue item before dispatch so it can't be reassigned mid-upload (#2615)

2026-07-20 12:30:39 +02:00

__init__.py

…