Move history from query data to ref and avoid rerenders

src/client/App.tsx

@@ -1,6 +1,9 @@
-import { QueryClient, QueryClientProvider, useQuery, useQueryClient } from '@tanstack/react-query';
+import { QueryClient, QueryClientProvider, useQuery } from '@tanstack/react-query';
+import { useSetAtom } from 'jotai';
+import { useEffect, useRef } from 'react';
 import './App.css';
 import { fetchDynamicData, fetchHistoryData, fetchStaticData } from './api';
+import { historyAtom } from './atoms';
 import { Cpu } from './components/chart-cards/cpu';
 import { Disks } from './components/chart-cards/disks';
 import { Memory } from './components/chart-cards/memory';
@@ -16,7 +19,8 @@ const refetchInterval = Number(import.meta.env.CLIENT_REFETCH_INTERVAL);
 const queryClient = new QueryClient();
 
 const Main = () => {
-  const queryClient = useQueryClient();
+  const history = useRef<HistoryNormalized>(null!);
+  const setHistoryRef = useSetAtom(historyAtom);
   const staticQuery = useQuery({
     queryKey: ['static'],
     queryFn: fetchStaticData,
@@ -26,28 +30,50 @@ const Main = () => {
 
   const historyQuery = useQuery({
     queryKey: ['history'],
-    queryFn: fetchHistoryData,
+    queryFn: async () => {
+      const data = await fetchHistoryData();
+      const maxes = {} as HistoryNormalized['maxes'];
+
+      for (const key of ['net', 'disks', 'temps'] as const) {
+        maxes[key] = data.reduce((max, slice) => Math.max(max, ...slice[key]), 0);
+      }
+
+      history.current = {
+        data,
+        maxes,
+      };
+      return data;
+    },
   });
 
   const dynamicQuery = useQuery({
     queryKey: ['dynamic'],
     queryFn: async () => {
       const data = await fetchDynamicData();
-      queryClient.setQueryData(['history'], (historyOld: HistorySlice[]) => {
-        const history = historyOld.slice();
-        while (history.length && history[0].timestamp < Date.now() - (serverSteps + 3) * serverRefreshInterval) {
-          history.shift();
+
+      if (history.current) {
+        while (
+          history.current.data.length &&
+          history.current.data[0].timestamp < Date.now() - (serverSteps + 3) * serverRefreshInterval
+        ) {
+          history.current.data.shift();
         }
 
-        history.push(data);
-        return history;
-      });
+        history.current.data.push(data);
+
+        for (const key of ['net', 'disks', 'temps'] as const) {
+          history.current.maxes[key] = history.current.data.reduce((max, slice) => Math.max(max, ...slice[key]), 0);
+        }
+      }
+
       return data;
     },
     refetchInterval: refetchInterval,
+    retry: true,
   });
 
   useSetTheme(window.matchMedia('(prefers-color-scheme: dark)').matches);
+  useEffect(() => setHistoryRef(history), [setHistoryRef]);
 
   const isLoading = staticQuery.isLoading || dynamicQuery.isLoading || historyQuery.isLoading;
 

src/client/api/types.ts

@@ -5,6 +5,7 @@ type StaticData = {
     brand: string;
     name: string;
     vendor_id: string;
+    threads: number;
   };
   host_name: string;
   kernel_version: string;
@@ -23,3 +24,8 @@ type HistorySlice = {
   temps: number[];
   timestamp: number;
 };
+
+type HistoryNormalized = {
+  data: HistorySlice[];
+  maxes: Record<'net' | 'disks' | 'temps', number>;
+};

src/client/atoms/index.ts

@@ -1,4 +1,6 @@
 import { atom } from 'jotai';
+import type { MutableRefObject } from 'react';
 
 export const highFpsAtom = atom(true);
 export const siAtom = atom(false);
+export const historyAtom = atom<MutableRefObject<HistoryNormalized>>({ current: null! });

src/client/components/chart-cards/common/card.tsx

@@ -1,4 +1,4 @@
-import { Legend, type LegendProps } from '@/components/chart-cards/common/legend';
+import { Legend, type LegendByDataProps, type LegendByKeyProps } from '@/components/chart-cards/common/legend';
 import type { FormatOptions } from '@/utils/format';
 import type { ReactNode } from 'react';
 import { CanvasChart } from './chart';
@@ -6,7 +6,7 @@ import { CanvasChart } from './chart';
 type Props = {
   title: ReactNode;
   subtitle?: ReactNode;
-  legend?: LegendProps;
+  legend?: Omit<LegendByKeyProps, 'dataKey'> | LegendByDataProps;
   formatOptions?: FormatOptions;
   domain?: [number, number];
   hardDomain?: boolean;
@@ -22,7 +22,8 @@ export const ChartCard = ({ dataKey, legend, hueOffset = 0, title, subtitle, for
 
       {subtitle}
 
-      {legend && (
+      {legend && (dataKey || 'values' in legend) && (
+        // @ts-expect-error: not inferable, but safe
         <Legend
           hueOffset={hueOffset}
           formatOptions={formatOptions}

src/client/components/chart-cards/common/chart/index.tsx

@@ -1,8 +1,9 @@
+import { historyAtom } from '@/atoms';
 import { useAnimationFrame } from '@/hooks/use-animation-frame';
 import { getFillColor, getStrokeColor } from '@/utils/colors';
 import type { FormatOptions } from '@/utils/format';
-import { useQuery } from '@tanstack/react-query';
-import { useEffect, useMemo, useRef, useState } from 'react';
+import { useAtomValue } from 'jotai';
+import { useEffect, useRef, useState } from 'react';
 import './index.css';
 import { YAxis } from './y-axis';
 
@@ -24,21 +25,9 @@ const xFromTimestamp = (timestamp: number, width: number) =>
 
 export const CanvasChart = ({ total, hueOffset = 0, domain, hardDomain, dataKey, formatOptions }: Props) => {
   const canvasRef = useRef<HTMLCanvasElement>(null!);
-  const { data: historyData } = useQuery<HistorySlice[]>({ queryKey: ['history'] });
-  const targetMax = useMemo(() => {
-    if (domain && hardDomain) {
-      return domain[1];
-    }
-
-    const historyMax = (historyData ?? []).reduce((max, slice) => Math.max(max, ...slice[dataKey]), 0);
-
-    if (!domain || historyMax > domain[1]) {
-      return historyMax;
-    }
-
-    return domain[1];
-  }, [domain, hardDomain, historyData, dataKey]);
-  const max = useRef(targetMax);
+  const history = useAtomValue(historyAtom);
+  const [lockedTargetMax, setLockedTargetMax] = useState(domain?.[1] ?? 0);
+  const max = useRef(lockedTargetMax);
 
   const [width, setWidth] = useState(640);
   const [height, setHeight] = useState(480);
@@ -61,10 +50,28 @@ export const CanvasChart = ({ total, hueOffset = 0, domain, hardDomain, dataKey,
   // Redraw chart
   useAnimationFrame(() => {
     const ctx = canvasRef.current.getContext('2d');
-    if (!ctx || !historyData) {
+    if (!ctx || !history.current) {
       return;
     }
 
+    const targetMax = (() => {
+      if (domain && hardDomain) {
+        return domain[1];
+      }
+
+      const historyMax = history.current.maxes[dataKey as keyof typeof history.current.maxes] ?? 0;
+
+      if (!domain || historyMax > domain[1]) {
+        return historyMax;
+      }
+
+      return domain[1];
+    })();
+
+    if (lockedTargetMax !== targetMax) {
+      setLockedTargetMax(targetMax);
+    }
+
     if (!hardDomain) {
       max.current = (4 * max.current + targetMax) / 5;
     }
@@ -96,16 +103,16 @@ export const CanvasChart = ({ total, hueOffset = 0, domain, hardDomain, dataKey,
 
         ctx.beginPath();
         ctx.moveTo(-xMargin, height);
-        ctx.lineTo(-xMargin, height - (height * (historyData[0][dataKey][i] ?? 0)) / max.current);
+        ctx.lineTo(-xMargin, height - (height * (history.current.data[0][dataKey][i] ?? 0)) / max.current);
 
-        for (const { timestamp, [dataKey]: values } of historyData) {
+        for (const { timestamp, [dataKey]: values } of history.current.data) {
           const x = xFromTimestamp(timestamp, width);
           const y = height - (height * (values[i] ?? 0)) / max.current;
 
           ctx.lineTo(x, y);
         }
 
-        ctx.lineTo(width + xMargin, height - (height * (historyData[0][dataKey][i] ?? 0)) / max.current);
+        ctx.lineTo(width + xMargin, height - (height * (history.current.data[0][dataKey][i] ?? 0)) / max.current);
         ctx.lineTo(width + xMargin, height);
 
         if (type === 'fill') ctx.fill();
@@ -121,7 +128,7 @@ export const CanvasChart = ({ total, hueOffset = 0, domain, hardDomain, dataKey,
 
   return (
     <div className='chart'>
-      <YAxis max={targetMax} formatOptions={formatOptions} />
+      <YAxis max={lockedTargetMax} formatOptions={formatOptions} />
 
       <div className='canvas-wrapper'>
         <canvas ref={canvasRef} width={width} height={height} />

src/client/components/chart-cards/common/legend/index.tsx

@@ -1,25 +1,24 @@
 import { getTextColor } from '@/utils/colors';
 import { type FormatOptions, formatValue } from '@/utils/format';
 import { useQuery } from '@tanstack/react-query';
-import { useMemo } from 'react';
+import { memo, useMemo } from 'react';
 import './index.css';
 
-type LegendCommonProps = {
+export type LegendCommonProps = {
   labels: string[];
   formatOptions?: FormatOptions;
   hueOffset?: number;
 };
 
-type LegendByKeyProps = LegendCommonProps & {
+export type LegendByKeyProps = LegendCommonProps & {
   dataKey: Exclude<keyof HistorySlice, 'timestamp'>;
+  totals?: number[];
 };
 
-type LegendByDataProps = LegendCommonProps & {
+export type LegendByDataProps = LegendCommonProps & {
   values: string[] | number[];
 };
 
-export type LegendProps = LegendByDataProps | LegendByKeyProps;
-
 export const LegendByData = ({ labels, formatOptions, hueOffset = 0, values }: LegendByDataProps) => (
   <div className='legend-wrapper'>
     {labels.map((label, index) => (
@@ -36,15 +35,26 @@ export const LegendByData = ({ labels, formatOptions, hueOffset = 0, values }: L
   </div>
 );
 
-export const LegendByKey = ({ dataKey, ...rest }: LegendByKeyProps) => {
-  const { data: historyData } = useQuery<HistorySlice[]>({ queryKey: ['history'] });
-  const values = useMemo(() => historyData?.at(-1)?.[dataKey], [historyData, dataKey]);
+export const LegendByKey = memo(({ dataKey, totals, formatOptions, ...rest }: LegendByKeyProps) => {
+  const { data: dynamicData } = useQuery<HistorySlice>({ queryKey: ['dynamic'] });
+  const values = useMemo(
+    () =>
+      dynamicData?.[dataKey]?.map((value, index) => {
+        if (totals) {
+          return `${formatValue(value, formatOptions)} / ${formatValue(totals[index], formatOptions)}`;
+        }
+
+        return formatValue(value, formatOptions);
+      }),
+    [dynamicData, dataKey, formatOptions, totals],
+  );
+
   if (values) {
     return <LegendByData {...rest} values={values} />;
   }
-};
+});
 
-export const Legend = (props: LegendProps) => {
+export const Legend = (props: LegendByDataProps | LegendByKeyProps) => {
   if ('values' in props) {
     return <LegendByData {...props} />;
   }

src/client/components/chart-cards/cpu.tsx

@@ -3,30 +3,25 @@ import { ChartCard } from './common/card';
 
 export const Cpu = () => {
   const { data: staticData } = useQuery<StaticData>({ queryKey: ['static'] });
-  const { data: historyData } = useQuery<HistorySlice[]>({ queryKey: ['history'] });
 
-  if (!staticData || !historyData) {
+  if (!staticData) {
     return <div />;
   }
 
-  const total_cpus = historyData[0].cpu.length;
-
   return (
-    !!total_cpus && (
-      <ChartCard
-        title='CPU'
-        subtitle={
-          <h3>
-            {staticData.cpu.brand}
-            <small>{` (${total_cpus} threads)`}</small>
-          </h3>
-        }
-        domain={[0, 100]}
-        hardDomain
-        formatOptions={{ prefix: false, units: '%' }}
-        dataKey={'cpu'}
-        total={total_cpus}
-      />
-    )
+    <ChartCard
+      title='CPU'
+      subtitle={
+        <h3>
+          {staticData.cpu.brand}
+          <small>{` (${staticData.cpu.threads} threads)`}</small>
+        </h3>
+      }
+      domain={[0, 100]}
+      hardDomain
+      formatOptions={{ prefix: false, units: '%' }}
+      dataKey={'cpu'}
+      total={staticData.cpu.threads}
+    />
   );
 };

src/client/components/chart-cards/disks.tsx

@@ -1,20 +1,13 @@
 import { siAtom } from '@/atoms';
-import { useQuery } from '@tanstack/react-query';
 import { useAtomValue } from 'jotai';
 import { ChartCard } from './common/card';
 
 export const Disks = () => {
-  const { data: historyData } = useQuery<HistorySlice[]>({ queryKey: ['history'] });
   const isSi = useAtomValue(siAtom);
 
-  if (!historyData) {
-    return <div />;
-  }
-
   return (
     <ChartCard
       title='Disk activity'
-      // @ts-expect-error: write a better union later
       legend={{
         labels: ['Read', 'Write'],
       }}

src/client/components/chart-cards/memory.tsx

@@ -1,26 +1,13 @@
 import { siAtom } from '@/atoms';
-import { formatValue } from '@/utils/format';
 import { useQuery } from '@tanstack/react-query';
 import { useAtomValue } from 'jotai';
-import { useMemo } from 'react';
 import { ChartCard } from './common/card';
 
 export const Memory = () => {
   const { data: staticData } = useQuery<StaticData>({ queryKey: ['static'] });
-  const { data: historyData } = useQuery<HistorySlice[]>({ queryKey: ['history'] });
   const isSi = useAtomValue(siAtom);
-  const formatOptions = { units: 'B', ...(isSi && { si: true }) };
 
-  const formatedTotals = useMemo(() => {
-    if (!staticData) {
-      return [];
-    }
-    return [formatValue(staticData.total_memory, formatOptions), formatValue(staticData.total_swap, formatOptions)];
-  }, [staticData, formatOptions]);
-
-  const last = useMemo(() => historyData?.at(-1), [historyData]);
-
-  if (!staticData || !historyData || !last) {
+  if (!staticData) {
     return <div />;
   }
 
@@ -28,15 +15,12 @@ export const Memory = () => {
     <ChartCard
       title='Memory'
       legend={{
-        values: [
-          `${formatValue(last.mem[0], formatOptions)} / ${formatedTotals[0]}`,
-          `${formatValue(last.mem[1], formatOptions)} / ${formatedTotals[1]}`,
-        ],
+        totals: [staticData.total_memory, staticData.total_swap],
         labels: ['Memory', 'Swap'],
       }}
       domain={[0, Math.max(staticData.total_memory, staticData.total_swap)]}
       hardDomain
-      formatOptions={formatOptions}
+      formatOptions={{ units: 'B', ...(isSi && { si: true }) }}
       dataKey={'mem'}
       total={2}
     />

src/client/components/chart-cards/network.tsx

@@ -1,20 +1,13 @@
 import { siAtom } from '@/atoms';
-import { useQuery } from '@tanstack/react-query';
 import { useAtomValue } from 'jotai';
 import { ChartCard } from './common/card';
 
 export const Network = () => {
-  const { data: historyData } = useQuery<HistorySlice[]>({ queryKey: ['history'] });
   const isSi = useAtomValue(siAtom);
 
-  if (!historyData) {
-    return <div />;
-  }
-
   return (
     <ChartCard
       title='Network'
-      // @ts-expect-error: write a better union later
       legend={{
         labels: ['Down', 'Up'],
       }}

src/client/components/chart-cards/temps.tsx

@@ -3,16 +3,14 @@ import { ChartCard } from './common/card';
 
 export const Temps = () => {
   const { data: staticData } = useQuery<StaticData>({ queryKey: ['static'] });
-  const { data: historyData } = useQuery<HistorySlice[]>({ queryKey: ['history'] });
 
-  if (!staticData || !historyData) {
+  if (!staticData) {
     return <div />;
   }
 
   return (
     <ChartCard
       title='Temperatures'
-      // @ts-expect-error: write a better union later
       legend={{
         labels: staticData.components,
       }}

src/stats-server/main.rs

@@ -151,6 +151,7 @@ async fn static_sysinfo_get() -> impl IntoResponse {
     );
 
     let components = Components::new_with_refreshed_list();
+    let cpus = sys.cpus();
 
     Response::builder()
         .header(axum::http::header::ORIGIN, "*")
@@ -167,9 +168,10 @@ async fn static_sysinfo_get() -> impl IntoResponse {
                 "total_memory": sys.total_memory(),
                 "total_swap": sys.total_swap(),
                 "cpu": {
-                    "name": sys.cpus()[0].name(),
-                    "vendor_id": sys.cpus()[0].vendor_id(),
-                    "brand": sys.cpus()[0].brand(),
+                    "name": cpus[0].name(),
+                    "vendor_id": cpus[0].vendor_id(),
+                    "brand": cpus[0].brand(),
+                    "threads": cpus.len(),
                 },
                 "components": components
                 .iter()