homeio

1import "server-only";
2
3import { logServerAction } from "@/lib/server/logging/logger";
4import { getSystemMetricsSnapshot } from "@/lib/server/modules/system/service";
5import type {
6  MetricsHistory,
7  MetricsHistoryPoint,
8  MetricsHistoryRange,
9} from "@/lib/shared/contracts/system";
10import { METRICS_HISTORY_SAMPLE_MS, toHistoryPoint } from "@/lib/shared/metrics-history";
11
12export const HISTORY_SAMPLE_MS = METRICS_HISTORY_SAMPLE_MS;
13export { toHistoryPoint };
14const MINUTE_MS = 60_000;
15const HOUR_MS = 60 * MINUTE_MS;
16const DAY_MS = 24 * HOUR_MS;
17const HOUR_CAPACITY = HOUR_MS / HISTORY_SAMPLE_MS;
18const DAY_CAPACITY = DAY_MS / MINUTE_MS;
19const ERROR_LOG_COOLDOWN_MS = 5 * MINUTE_MS;
20
21type MetricKey = Exclude<keyof MetricsHistoryPoint, "t">;
22const METRIC_KEYS: MetricKey[] = [
23  "cpuPercent",
24  "memoryPercent",
25  "temperatureCelsius",
26  "downloadMbps",
27  "uploadMbps",
28  "diskReadMBps",
29  "diskWriteMBps",
30];
31
32type MinuteBucket = {
33  start: number;
34  sums: Record<MetricKey, number>;
35  counts: Record<MetricKey, number>;
36};
37
38function emptyBucket(start: number): MinuteBucket {
39  const zeros = () =>
40    Object.fromEntries(METRIC_KEYS.map((key) => [key, 0])) as Record<MetricKey, number>;
41  return { start, sums: zeros(), counts: zeros() };
42}
43
44function averageOf(bucket: MinuteBucket): MetricsHistoryPoint {
45  const point = { t: bucket.start } as MetricsHistoryPoint;
46  for (const key of METRIC_KEYS) {
47    const count = bucket.counts[key];
48    point[key] = count > 0 ? bucket.sums[key] / count : null;
49  }
50  return point;
51}
52
53/**
54 * The last hour at full resolution plus 24 hours of one-minute averages, all in
55 * memory: the charts survive a page refresh and closing the Monitor, not a
56 * Homeio restart.
57 */
58export function createMetricsHistory() {
59  const hour: MetricsHistoryPoint[] = [];
60  const day: MetricsHistoryPoint[] = [];
61  let bucket: MinuteBucket | null = null;
62
63  function record(point: MetricsHistoryPoint) {
64    hour.push(point);
65    if (hour.length > HOUR_CAPACITY) hour.shift();
66
67    const minuteStart = point.t - (point.t % MINUTE_MS);
68    if (bucket && bucket.start !== minuteStart) {
69      day.push(averageOf(bucket));
70      if (day.length > DAY_CAPACITY) day.shift();
71      bucket = null;
72    }
73    bucket ??= emptyBucket(minuteStart);
74    for (const key of METRIC_KEYS) {
75      const value = point[key];
76      if (typeof value !== "number") continue;
77      bucket.sums[key] += value;
78      bucket.counts[key] += 1;
79    }
80  }
81
82  function get(range: MetricsHistoryRange, now: number): MetricsHistory {
83    if (range !== "24h") {
84      // 15 min is the tail of the hour, at the same 5 s resolution.
85      const since = now - (range === "15m" ? 15 * MINUTE_MS : HOUR_MS);
86      return {
87        range,
88        intervalSeconds: HISTORY_SAMPLE_MS / 1000,
89        points: hour.filter((point) => point.t > since),
90      };
91    }
92
93    // The minute in progress is included so the last point is never stale.
94    const points = day.filter((point) => point.t > now - DAY_MS);
95    if (bucket) points.push(averageOf(bucket));
96    return { range, intervalSeconds: MINUTE_MS / 1000, points };
97  }
98
99  return { record, get };
100}
101
102type MetricsHistoryStore = ReturnType<typeof createMetricsHistory>;
103
104declare global {
105  var __homeioMetricsHistory: MetricsHistoryStore | undefined;
106  var __homeioMetricsHistoryStarted: boolean | undefined;
107}
108
109// instrumentation.ts (which starts the sampler) and the API route are bundled
110// separately, so each gets its own copy of this module. Keep one buffer on
111// globalThis, in production too, or the route would read an empty history.
112const history = (globalThis.__homeioMetricsHistory ??= createMetricsHistory());
113let lastErrorLoggedAt = 0;
114
115async function sample() {
116  try {
117    const snapshot = await getSystemMetricsSnapshot();
118    history.record(toHistoryPoint(snapshot, Date.now()));
119  } catch (error) {
120    const now = Date.now();
121    if (now - lastErrorLoggedAt < ERROR_LOG_COOLDOWN_MS) return;
122    lastErrorLoggedAt = now;
123    logServerAction({
124      level: "warn",
125      layer: "service",
126      action: "system.metrics.history.sample",
127      status: "error",
128      message: "Could not record a metrics history sample",
129      error,
130    });
131  }
132}
133
134export function startMetricsHistory() {
135  if (globalThis.__homeioMetricsHistoryStarted) return;
136  globalThis.__homeioMetricsHistoryStarted = true;
137  void sample();
138  setInterval(() => void sample(), HISTORY_SAMPLE_MS).unref();
139}
140
141export function getMetricsHistory(range: MetricsHistoryRange): MetricsHistory {
142  return history.get(range, Date.now());
143}
144