Replace unused server metrics with a count (Refs #139)

src/lib/server/fleet/metrics.ts

@@ -13,7 +13,6 @@ import {
     type MetricsQuery,
     type PreviousMetrics,
     type RunningMetrics,
-    type ServerMetrics,
     type Utilization
 } from '../../metrics.js';
 
@@ -191,17 +190,13 @@ export function readMetrics(input: MetricsDays | MetricsQuery, now = Date.now())
         );
     const globalBounds = evidenceBounds(groups);
     const scopedBounds = evidenceBounds(groups.filter(matchesScope));
-    const registered = new Set(
-        (
-            handle.prepare('SELECT name FROM servers WHERE destroyed_at IS NULL').all() as {
-                name: string;
-            }[]
-        ).map((server) => server.name)
-    );
+    const registered = handle
+        .prepare('SELECT COUNT(*) AS count FROM servers WHERE destroyed_at IS NULL')
+        .get() as { count: number };
     const metadata = {
         firstRetainedSampleAt: globalBounds.first,
         latestSampleAt: globalBounds.latest,
-        registeredServerCount: registered.size,
+        registeredServerCount: registered.count,
         scopeFirstSampleAt: scopedBounds.first,
         scopeLatestSampleAt: scopedBounds.latest
     };
@@ -236,7 +231,7 @@ export function readMetrics(input: MetricsDays | MetricsQuery, now = Date.now())
         lastSampleAt: null,
         partialHistory: false
     };
-    const serverTotals = new Map<string, ServerMetrics>();
+    const sampledServers = new Set<string>();
     const mapTotals = new Map<string, Map<string, MapMetrics>>();
     function mapFor(gameName: string, label: string): MapMetrics {
         let game = mapTotals.get(gameName);
@@ -401,8 +396,8 @@ export function readMetrics(input: MetricsDays | MetricsQuery, now = Date.now())
             for (const sample of samples)
                 addObservation(previous.summary, sample.players, priorHours);
         }
-        // Preserve current-window zero-duration rows without bringing rows from
-        // the separate comparison window into the visible server/map tables.
+        // Preserve current-window zero-duration evidence without bringing samples
+        // from the separate comparison window into the current count or map table.
         if (at < since - ONLINE_MAX_MS) return;
         const start = Math.max(at, since);
         const hours = Math.max(0, end - start) / 3600_000;
@@ -425,18 +420,9 @@ export function readMetrics(input: MetricsDays | MetricsQuery, now = Date.now())
             cursor = stop;
         }
         for (const sample of samples) {
-            let server = serverTotals.get(sample.server);
-            if (!server) {
-                server = {
-                    server: sample.server,
-                    currentRegistered: registered.has(sample.server),
-                    ...emptyUtilization()
-                };
-                serverTotals.set(sample.server, server);
-            }
+            sampledServers.add(sample.server);
             const map = mapFor(sample.game, sample.map);
             addObservation(summary, sample.players, hours);
-            addObservation(server, sample.players, hours);
             addObservation(map, sample.players, hours);
             for (const slice of slices) addObservation(slice.point, sample.players, slice.hours);
             if (sample.players === null) counts.unknown++;
@@ -493,9 +479,6 @@ export function readMetrics(input: MetricsDays | MetricsQuery, now = Date.now())
     }
     aggregateBatch(now);
 
-    const servers = [...serverTotals.values()].sort(
-        (a, b) => b.active - a.active || compareText(a.server, b.server)
-    );
     const maps = [...mapTotals.values()]
         .flatMap((game) => [...game.values()])
         .sort(
@@ -531,7 +514,7 @@ export function readMetrics(input: MetricsDays | MetricsQuery, now = Date.now())
         summary,
         running,
         matches: matchMetrics(totalMatches),
-        servers,
+        sampledServerCount: sampledServers.size,
         maps,
         points,
         previous,