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.
Five tasks, four delegated to agents on disjoint files and one on the critical
path. Board and verification log: ~/.opencode/plan/vellum-beta-tasks.md
T1 Async scans (coordinator)
- migration 0007 adds ref_id + result to jobs, indexed by (kind, ref_id, id),
so a job can be found by what it operates on and can report back.
- jobs: EnqueueRef, JobID(ctx) so a handler can attach a result, SetResult.
- POST /libraries/{id}/scan now enqueues and returns 202; a real library takes
longer than any request timeout, and a hanging request looks like a broken
server. GET /libraries/{id}/scan/status reports the latest run.
- Libraries.svelte polls and shows "Scanning…" instead of freezing.
T2 Admin CLI (agent)
- internal/cli: `user add|passwd|list`, `backup <path>` via VACUUM INTO, with
tests. Wired into main.go, which the coordinator kept.
T3 Deploy (agent)
- compose.yml now mounts all six media kinds read-only with :z and carries the
metadata env keys. DEPLOY.md covers volumes, SELinux, admin bootstrap, TLS,
backup and upgrade.
T4 Pagination (agent)
- GET /items takes offset and returns total; Browse loads 60 at a time with
"Load more" and "Showing X of Y" instead of silently truncating at 300.
T5 Password change UI (agent)
- A Password section in Settings with validation, busy and success states.
Verified end to end: scan returns 202 in 0.7 ms and polls to done; the CLI
created a user, changed a password, and produced a complete 240 KB backup while
the server ran; pagination reports total 8 and pages correctly; compose parses
with every mount :z. go vet and 14 test packages pass; svelte-check 0/0.
- jobs: a table-backed queue in the same SQLite file. No Redis, no second
process, included in the same backup. claim() is a single UPDATE...RETURNING
so a job cannot run twice even with several workers. Failures back off
exponentially; a missing handler fails permanently rather than retrying a
bug.
- metadata: Provider interface plus Open Library and Google Books (both
keyless). The enricher tries providers in registration order, falls back on
empty, and continues past a provider error.
- migration 0004: metadata_fetch records the attempt, not just the match, so a
rescan does not re-hammer a rate-limited API for an item that will never
match. Errors are always retried; ok/notfound are cached for 30 days.
- enrichment writes provider_ids, updates title/year, links authors through
people/item_people, and downloads the cover as an asset. The cover download
runs outside the transaction: a slow image host must not hold a write lock.
- endpoints: queue enrichment per library, and inspect an item's matches.
- web: Enrich button per library.
Verified live against Open Library: "The Hobbit" matched /works/OL27482W,
title and year 1937 written, a 301x500 JPEG cover downloaded and served.
