Joseph Doherty
77c5731b7b
The snapshot publisher broadcast to Clients.All on every ~1s tick forever, with zero viewers. Each tick cost a session-registry snapshot and sort, a metrics snapshot that copies dictionaries under the global metrics lock, a full rebuild of EffectiveGatewayConfiguration, and a SQLite read of the API key table. DashboardSnapshotHub now counts live connections into the singleton DashboardSnapshotHubConnectionCounter (clamped at zero, since SignalR can call OnDisconnectedAsync for a connection whose OnConnectedAsync faulted). The publisher drives the snapshot enumerator by hand instead of await foreach: with no connections it does not call MoveNextAsync at all, so the producing iterator stays suspended at its yield and no snapshot is built — the gate removes the build, not just the broadcast. It re-checks once a second, so the first viewer resumes the tick within about one interval; that viewer is seeded immediately by DashboardPageBase's synchronous GetSnapshot() and by the hub's OnConnectedAsync. Two per-tick costs are bounded independently of the gate: the effective configuration is startup-static (options are bound once at boot and never reloaded), so it is built once and cached; and the API key summaries refresh at most every 15s, since the list only changes when an operator creates, rotates, or revokes a key. Only a successful refresh restarts the interval, so a failed or timed-out read is still retried on the next tick with the previous summaries left on screen.