Review finding P1 on #591: in folder mode a source key folder that is a
link or junction to a folder outside was still handed to the planner, so
Convert outdated could remove an older-format file outside the thumbnail
folder. ensure_store now refuses a linked store before any planning, and
each removal of an old preview passes may_write at the moment it runs.
An old thumbnail the finishing move cannot remove (held open on Windows)
is now an error row of the job with its path, and logged; a failed copy's
temp that cannot go is logged with its path. Every except that only
passes says why, and the thread runners say their caller re-raises.
POST /images/thumbnails/plan reviews a move (what is copied, removed and
left, free space, too-long Windows paths, sources no longer listed) and
hands out a token; POST /jobs/thumbnails {mode: move} runs it as a
thumbnails job: hold automatic previews, copy and check every preview on
the job pool, switch with one config commit that records the old copies,
then remove them. Per-file errors still switch; a folder-wide error, a
cancel before the switch or a crash leaves nothing changed (a journal is
undone at the next start); old copies that could not go are removed by a
finishing job at the next start. Leaving a folder removes the previews of
this install's sources that are no longer listed (Q320-8).
Recreate folder and Use this folder answer an unavailable folder; the
Thumbnail maintenance scope prune removes the thumbnails of removed
sources.
Marker keys are data, not paths: only a single <slug>-<hex> folder name
is ever joined onto the thumbnail folder; anything else is dropped and
logged. Every preview write and delete passes one ownership check (below a
key folder, lexically and resolved, no link, junction or reparse point on
the way); make_parent refuses anything else and writes nothing while the
folder lacks this install's marker (an unmounted mount point). Clear never
descends into a junction.
The configured location is in force before any request (unchecked folder
mode is unavailable), and a startup check that fails leaves it invalid,
never the sources. Older listings that run on the event loop no longer
touch the store in folder mode. A leftover under another case of
thumbnails/ on a case-insensitive disk is refused too.
thumbnails.location in config.json can now name one folder for every
source's previews: <folder>/<source key>/<rel>_thumb<ext>. A source key is
a readable slug plus a short hash of the source's identity, stored in the
folder's marker (.promptmanager-thumbnails.json) with the install that
made it. Serving, on-demand and capture writes, listings, clear, delete,
duplicates, the temp sweep and History covers all follow it; a leftover in
<source>/thumbnails is never served and other text under thumbnails/ is
refused.
A missing, unplugged or foreign folder is unavailable (a probe checks it
every 5 s within 2 s; a stalled or failing store call flips it at once):
originals are served, nothing is written anywhere, the folder is never
re-created, and generate, convert and clear answer 409
location-unavailable. A bad config value is unavailable too, never a
fall-back to the sources.
No UI yet: POST /settings refuses thumbnail_location (409
location-needs-move); GET /settings reports it with its path, the
thumbnail status without one. Sources inside or around the folder and a
library move into it are refused.
A planned target keeps the plan's own containment rule (inside the
store, as the thumbnail job writes it); captures keep the serve rule.
The structural test also covers PREVIEW_FOLDER joins and the
repo-root modules; the write-lock test asserts the lock instead of
waiting on a timer; new tests cover nested roots in the after-scan
queue and a legacy upper-case preview served through the resolver.
Add py/api/preview_store.py: the store of a source, a preview's path,
URL parts to disk, containment (owns), a write generation and the lock
around every preview's final rename. Every preview reader, writer and
remover now asks it instead of joining <source>/thumbnails by hand:
serve, on-demand, capture (its path resolved when the write starts),
the after-scan queue, the thumbnail plans and job payloads, clear, the
temp sweep, History covers, the auto-tag listing and the owned-preview
lookups.
Source mode only: every path is the one built before, so nothing
changes on disk or on the wire. A structural test keeps new
thumbnails joins out of the backend.
Vito Sansevero