The "Refreshing backup data..." step on every WebUI update fired one
`restic stats` (restore-size mode — the slowest restic op) plus ~4
identical unfiltered `restic snapshots --json` pulls per enabled
location (dashboard, snapshots, app-status, migrate each pulled their
own), all over a fresh SSH connection for remote repos, on every pass
with no throttle — the slow, "frozen"-looking line users hit on poor
links.
Two fixes:
1. Dedupe. engineSnapshotsJson transparently memoises the first
unfiltered whole-repo pull per location to a shared cache dir
(LP_SNAP_CACHE_DIR, set by webui_updater around the chain), so the
four generators reuse one restic call instead of four. Filtered and
failed/empty pulls always fall through to a live call.
2. Throttle. Backups and location changes already regenerate this data
live when they happen, so the routine pass is only a drift catch-up.
Split the cheap local-only generators (engines/schema/passwords —
no remote I/O) out to always run, and gate the remote pull behind
CFG_BACKUP_DASHBOARD_REFRESH_INTERVAL (minutes, default 30, 0 =
every update). A completed backup touches a dirty marker that forces
the next pass to pull; WEBUI_UPDATER_FORCE still forces a full
refresh.
Net: N locations x 5 remote restic calls every update -> 1 call per
location, only when something actually changed.
Co-Authored-By: Claude Opus 4.8 (1M context) <noreply@anthropic.com>
Signed-off-by: librelad <librelad@digitalangels.vip>