A 50k-file library used to wedge the database. This wave fixes the four
reasons why, plus a timestamp-ordering bug the work exposed.
Chunked scans (internal/library/scan.go)
- One transaction wrapped the whole reconciliation, holding SQLite's single
write lock for the entire scan. Now 500 groups per transaction, and the two
missing-file passes are batched too.
- Verified: a 20,000-file scan reports partial progress (scanned=1500 mid-scan)
and a concurrent progress save returns 200 throughout. Under the old code
that save blocked for the whole scan.
- Behaviour change: a scan is no longer all-or-nothing. A crash now leaves a
consistent partial scan. The scan is idempotent, so re-running finishes it.
- res.Errors is capped at 100 (a broken mount used to append one string per
file, then serialise the lot into the job row); the overflow is counted.
Concurrent job workers (internal/jobs/jobs.go)
- Run() was single-threaded, so a scan stalled every enrichment job behind it.
Now 4 workers with jittered idle waits.
- Handlers run concurrently, so Register/lookup take an RWMutex, and a
panicking handler is recovered and marked failed rather than killing a worker
and stranding a row in 'running'.
- RecoverStale() requeues jobs left 'running' by a dead process; called at boot
from main.go. Previously such a job stayed 'running' forever and the UI
polled it forever.
Explore (internal/media/discover.go)
- Full-scanned and sorted the whole library on every home load, and was
deterministic, so it showed the same 30 items every visit. Now a per-kind
fair-share id range scan with a random start, wrap-around, dedup and
interleaving. The doc comment claimed per-kind sampling before; now it does.
Indexes (migrations/0008_query_indexes.sql)
- Benchmarked with ANALYZE over 60k items: browse page 1 13.37ms -> 0.03ms
(484x, full scan -> covering index), deep page 8x, recently added 3.2x.
- A candidate index for the Continue shelf was built, measured and REJECTED:
the planner never chose it because `finished = 0` selects the majority of a
user's rows, so it had no selectivity and would have cost a write on every
progress save. Recorded in the migration rather than shipped as dead weight.
Canonical timestamps (internal/core/stamp.go)
- time.RFC3339Nano trims trailing zeros, so its fraction width varies and the
strings are not lexicographically sortable: ".5Z" > ".55Z" as strings though
.500s < .550s. That broke every ORDER BY <timestamp> and MAX(timestamp),
including the Continue shelf and Most Viewed. It was wrong even in columns
written 100% by Go, so it was not a cross-format issue.
- All 14 write sites now use core.Stamp, matching SQLite's own default format
exactly. Read paths are untouched: RFC3339Nano parses both shapes, so
existing rows keep working.
Also: busy_timeout 5s -> 15s. Chunked scans still delay a concurrent write, and
measured tail latency on a first scan of 15k new files reached 3.3s, leaving
almost no margin at 5s. Waiting beats failing with SQLITE_BUSY and losing a
playback position. A 10ms inter-batch yield was implemented, measured, found to
have no effect distinguishable from noise (overlapping ranges), and removed.
Verified end to end, not just compiled: orphan recovery logged at boot, scan
returns 202 in 0.7ms, Explore varies across loads, concurrent writes survive a
scan. gofmt/vet clean, 14 packages pass, -race clean on the queue, svelte-check
0/0, fresh install applies all 8 migrations.
The landing screen now reads as a product rather than a list.
- migration 0006: item_views, per user. "Most viewed" is personal — what I
re-read is not what you re-read. Counted when an item is opened in a reader,
so the number means consumed, not merely fetched.
- Suggestions: unstarted items related to what the user has been consuming —
same author first, then same kind, then recent as a floor. Each carries the
reason it was chosen ("More by Daft Punk"), because a suggestion nobody can
understand is noise.
- Explore: a mixed sample across every kind, excluding in-progress items so the
zone is discovery rather than a repeat.
- Home fetches all five shelves in one request; the screen never pops in.
- web: Shelf gained subtitle/badge support, Card gained a subtitle, and the
home renders four shelves plus a wrapping Explore grid.
Three bugs found and fixed while verifying:
- Continue showed a multi-track audiobook once per chapter. GROUP BY item_id
with MAX(updated_at) picks one card per item (SQLite takes the bare columns
from the row that produced the max).
- Suggestions and Explore passed their SQL arguments in the wrong order: the IN
list precedes the user id in those queries, so a user id was being bound as a
library id. Covered by a scoping test that would have caught it.
- The sidebar lost its media types on a cold, logged-out load. bootstrap()
fetched media types inside a Promise.all with /auth/me, so the expected 401
rejected the whole thing and nothing refetched after login. Media types are
public and now load independently.
The app looked like an admin panel. This is the product people actually see
when they open their library.
- Home: a landing screen with a Continue shelf (progress bars, straight from
the progress table) and per-type shelves of recent additions. One request
feeds it, so it does not pop in piece by piece.
- Browse: cover grid per media type with type chips, plus browse-all. Powered
by a new GET /items that lists across every visible library, filtered by
kind, through the same access chokepoint.
- Item page: cover, kind, title, authors, progress, a primary action that says
Continue when you have started, description, and the file list for
multi-file items. Cards now open the item page rather than jumping straight
into a reader.
- Search: results grouped by media type, cover-forward.
- Navigation moved from "libraries" to "media types" — you browse Ebooks, not
"the Ebooks folder". Libraries became an admin concern.
- Design system: dark by default, cover-forward, one accent, tighter type
scale, horizontal shelves, skeleton loaders.
- media: GET /home, GET /items, and authors on item detail.
Verified by screenshot in a live instance: home shelves, browse grid, and item
page all render correctly.
