The Discover tab fanned out its whole request set twice on every cold
start and replayed slow rows on a shrinking timeout ladder, so a healthy
remote server produced anywhere from 4s to 15s of loading.
Measured against a remote Jellyfin server with four libraries, 24
interleaved cold-start samples per side:
requests 19 -> 9 payload 219 KB -> 94 KB
settled 5231ms -> 2502ms median, 13222ms -> 5927ms p95
Four independent causes:
- Retry policy. `Client.send` resolves on response headers, so the
connect budget covers the server's think time and a slow-but-alive
query raises `connectionTimeout`. Replaying it made the server re-run
the query with a shorter budget than the one it just missed; the
`[10s, 8s, 5s]` ladder turned an 11s answer into an empty row after
23s. Hub surfaces now get one whole-request deadline, retry only
immediate connection errors, and the deadline bounds the whole call
including the request still in flight.
- Request shape. `/Items/Latest` groups a TV library by series, so its
rows are Series folder dtos and `RecursiveItemCount`/`ChildCount` cost
a DB count each, per row. Hub rows now ask for `Overview` only; watch
state survives because Jellyfin derives `UserData.Played` from
`UnplayedItemCount` when the count fields are absent. `/Shows/NextUp`
sends `NextUpDateCutoff` to bound the server's series-key scan, and
`Thumb` leaves `EnableImageTypes` since nothing reads it. `UserData`
and `PremiereDate` leave the browse set: neither is an `ItemFields`
member, so the server dropped them anyway.
- Fan-out. Per-library hubs ran in batches of three separated by a
barrier, so one slow library stalled every library behind it. A
sliding window keeps the same peak concurrency without head-of-line
blocking. Concurrent `fetchLibraries` calls now share one `/Views`
instead of racing two identical round trips, Plex's global and music
hub legs start together, and Jellyfin gets Plex's pool tuning.
- Duplicate pass. `DiscoverScreen.initState` starts a load and the
online-entry hook asked for a full refresh on top of it, which
`CoalescedLoadCoordinator` correctly queued as a trailing pass. The
hook now calls `primeRefresh`, which rides along with a load already
in flight; profile switches still go through `fullRefresh`.
Refs #1784
Signing in triggered two back-to-back profile rebinds; the second re-added
the same Jellyfin connection, which tore down the live client and aborted
the home screen's in-flight fetches. The aborted pass was committed as
loaded-empty, flashing 'no content available' until the follow-up load
landed. Fix at the root instead of patching the sign-in window:
- addJellyfinConnection now reuses the live client when the connection is
unchanged (token, deviceId, URL set), matching the existing Plex
refreshTokensForProfile behavior; material changes still recreate it.
- Cancelled requests are classified end-to-end: the client's
treat-as-empty helpers rethrow cancellations, and the aggregation
fan-outs report cancelledServerIds alongside succeededServerIds.
- A fetch pass in which zero servers succeeded is never authoritative:
it keeps existing content instead of wiping it (also fixes the
pre-existing blanking of home/sidebar on a totally failed refresh),
stays in loading while disrupted (cancellation or binding in flight),
and only commits loaded-empty on a settled failure.
edde746