Add caching for api calls to speed them up. Added caching for cpu and gpu stat calls

ui/src/app/api/cpu/route.ts

@@ -3,44 +3,32 @@ import si from 'systeminformation';
 import { createRequire } from 'module';
 import os from 'os';
 import { CpuInfo } from '@/types';
+import { cached } from '@/server/apiCache';
 
 const isMac = os.platform() === 'darwin';
 
-export async function GET() {
-  try {
-    const cpuInfoRaw = await si.cpu();
-    let cpuInfo: CpuInfo;
+async function getCpuInfo(): Promise<CpuInfo> {
+  const cpuInfoRaw = await si.cpu();
+  let cpuInfo: CpuInfo;
 
-    if (isMac) {
-      try {
-        const nativeRequire = createRequire(import.meta.url);
-        const ms = nativeRequire('macstats') as any;
-        const ramData = ms.getRAMUsageSync();
-        const cpuData = ms.getCpuDataSync();
+  if (isMac) {
+    try {
+      const nativeRequire = createRequire(import.meta.url);
+      const ms = nativeRequire('macstats') as any;
+      const ramData = ms.getRAMUsageSync();
+      const cpuData = ms.getCpuDataSync();
 
-        cpuInfo = {
-          name: `${cpuInfoRaw.manufacturer} ${cpuInfoRaw.brand}`,
-          cores: cpuInfoRaw.cores,
-          temperature: cpuData.temperature || 0,
-          totalMemory: ramData.total / (1024 * 1024),
-          availableMemory: ramData.free / (1024 * 1024),
-          freeMemory: ramData.free / (1024 * 1024),
-          currentLoad: (await si.currentLoad()).currentLoad || 0,
-        };
-      } catch {
-        // Fallback to systeminformation if macstats fails
-        const memoryData = await si.mem();
-        cpuInfo = {
-          name: `${cpuInfoRaw.manufacturer} ${cpuInfoRaw.brand}`,
-          cores: cpuInfoRaw.cores,
-          temperature: (await si.cpuTemperature()).main || 0,
-          totalMemory: memoryData.total / (1024 * 1024),
-          availableMemory: memoryData.available / (1024 * 1024),
-          freeMemory: memoryData.free / (1024 * 1024),
-          currentLoad: (await si.currentLoad()).currentLoad || 0,
-        };
-      }
-    } else {
+      cpuInfo = {
+        name: `${cpuInfoRaw.manufacturer} ${cpuInfoRaw.brand}`,
+        cores: cpuInfoRaw.cores,
+        temperature: cpuData.temperature || 0,
+        totalMemory: ramData.total / (1024 * 1024),
+        availableMemory: ramData.free / (1024 * 1024),
+        freeMemory: ramData.free / (1024 * 1024),
+        currentLoad: (await si.currentLoad()).currentLoad || 0,
+      };
+    } catch {
+      // Fallback to systeminformation if macstats fails
       const memoryData = await si.mem();
       cpuInfo = {
         name: `${cpuInfoRaw.manufacturer} ${cpuInfoRaw.brand}`,
@@ -52,7 +40,25 @@ export async function GET() {
         currentLoad: (await si.currentLoad()).currentLoad || 0,
       };
     }
+  } else {
+    const memoryData = await si.mem();
+    cpuInfo = {
+      name: `${cpuInfoRaw.manufacturer} ${cpuInfoRaw.brand}`,
+      cores: cpuInfoRaw.cores,
+      temperature: (await si.cpuTemperature()).main || 0,
+      totalMemory: memoryData.total / (1024 * 1024),
+      availableMemory: memoryData.available / (1024 * 1024),
+      freeMemory: memoryData.free / (1024 * 1024),
+      currentLoad: (await si.currentLoad()).currentLoad || 0,
+    };
+  }
 
+  return cpuInfo;
+}
+
+export async function GET() {
+  try {
+    const cpuInfo = await cached('cpu-info', getCpuInfo);
     return NextResponse.json(cpuInfo);
   } catch (error) {
     console.error('Error fetching CPU stats:', error);

ui/src/app/api/gpu/route.ts

@@ -3,6 +3,7 @@ import { exec } from 'child_process';
 import { promisify } from 'util';
 import { createRequire } from 'module';
 import os from 'os';
+import { cached } from '@/server/apiCache';
 
 const execAsync = promisify(exec);
 
@@ -93,68 +94,73 @@ async function getMacGpuInfo(): Promise<MacGpuResult | null> {
   }
 }
 
-export async function GET() {
-  try {
-    // Get platform
-    const platform = os.platform();
-    const isWindows = platform === 'win32';
-    const isMac = platform === 'darwin';
+async function getGpuInfo() {
+  // Get platform
+  const platform = os.platform();
+  const isWindows = platform === 'win32';
+  const isMac = platform === 'darwin';
 
-    if (isMac) {
-      const macGpu = await getMacGpuInfo();
-      if (macGpu) {
-        return NextResponse.json({
-          hasNvidiaSmi: false,
-          isMac: true,
-          gpus: [
-            {
-              index: 0,
-              name: macGpu.name,
-              driverVersion: 'macOS',
-              temperature: Math.round(macGpu.temperature),
-              utilization: {
-                gpu: macGpu.gpuLoad,
-                memory: macGpu.memTotal > 0 ? Math.round((macGpu.memUsed / macGpu.memTotal) * 100) : 0,
-              },
-              memory: {
-                total: Math.round(macGpu.memTotal),
-                free: Math.round(macGpu.memTotal - macGpu.memUsed),
-                used: Math.round(macGpu.memUsed),
-              },
-              power: { draw: macGpu.powerDraw, limit: 0 },
-              clocks: { graphics: 0, memory: 0 },
-              fan: { speed: macGpu.fanSpeed },
-            },
-          ],
-        });
-      }
-      return NextResponse.json({
+  if (isMac) {
+    const macGpu = await getMacGpuInfo();
+    if (macGpu) {
+      return {
         hasNvidiaSmi: false,
         isMac: true,
-        gpus: [],
-        error: 'Could not read Mac GPU stats',
-      });
+        gpus: [
+          {
+            index: 0,
+            name: macGpu.name,
+            driverVersion: 'macOS',
+            temperature: Math.round(macGpu.temperature),
+            utilization: {
+              gpu: macGpu.gpuLoad,
+              memory: macGpu.memTotal > 0 ? Math.round((macGpu.memUsed / macGpu.memTotal) * 100) : 0,
+            },
+            memory: {
+              total: Math.round(macGpu.memTotal),
+              free: Math.round(macGpu.memTotal - macGpu.memUsed),
+              used: Math.round(macGpu.memUsed),
+            },
+            power: { draw: macGpu.powerDraw, limit: 0 },
+            clocks: { graphics: 0, memory: 0 },
+            fan: { speed: macGpu.fanSpeed },
+          },
+        ],
+      };
     }
+    return {
+      hasNvidiaSmi: false,
+      isMac: true,
+      gpus: [],
+      error: 'Could not read Mac GPU stats',
+    };
+  }
 
-    // Check if nvidia-smi is available
-    const hasNvidiaSmi = await checkNvidiaSmi(isWindows);
+  // Check if nvidia-smi is available
+  const hasNvidiaSmi = await checkNvidiaSmi(isWindows);
 
-    if (!hasNvidiaSmi) {
-      return NextResponse.json({
-        hasNvidiaSmi: false,
-        isMac: false,
-        gpus: [],
-        error: 'nvidia-smi not found or not accessible',
-      });
-    }
+  if (!hasNvidiaSmi) {
+    return {
+      hasNvidiaSmi: false,
+      isMac: false,
+      gpus: [],
+      error: 'nvidia-smi not found or not accessible',
+    };
+  }
 
-    // Get GPU stats
-    const gpuStats = await getGpuStats(isWindows);
+  // Get GPU stats
+  const gpuStats = await getGpuStats(isWindows);
 
-    return NextResponse.json({
-      hasNvidiaSmi: true,
-      gpus: gpuStats,
-    });
+  return {
+    hasNvidiaSmi: true,
+    gpus: gpuStats,
+  };
+}
+
+export async function GET() {
+  try {
+    const gpuInfo = await cached('gpu-info', getGpuInfo);
+    return NextResponse.json(gpuInfo);
   } catch (error) {
     console.error('Error fetching NVIDIA GPU stats:', error);
     return NextResponse.json(
@@ -248,4 +254,3 @@ async function getGpuStats(isWindows: boolean) {
 
   return gpus;
 }
-

ui/src/server/apiCache.ts

@@ -0,0 +1,59 @@
+type CacheEntry = {
+  promise: Promise<unknown>;
+  timestamp: number;
+};
+
+const cache = new Map<string, CacheEntry>();
+
+const DEFAULT_STALE_TIME_MS = 5000;
+
+/**
+ * Universal cache for slow API work. Results are cached per key + params and
+ * reused until they go stale. Concurrent callers while a fetch is in flight
+ * share the same promise instead of triggering duplicate work.
+ *
+ * @param key        Unique name for this cached operation (e.g. 'cpu-info')
+ * @param fetcher    Function that produces a fresh value
+ * @param staleTimeMs How long a cached value stays fresh (default 5000ms)
+ * @param params     Optional params; different params get separate cache entries
+ */
+export async function cached<T>(
+  key: string,
+  fetcher: () => Promise<T>,
+  staleTimeMs: number = DEFAULT_STALE_TIME_MS,
+  params: unknown = null,
+): Promise<T> {
+  const cacheKey = params === null ? key : `${key}:${JSON.stringify(params)}`;
+  const now = Date.now();
+
+  const entry = cache.get(cacheKey);
+  if (entry && now - entry.timestamp < staleTimeMs) {
+    return entry.promise as Promise<T>;
+  }
+
+  const promise = fetcher();
+  cache.set(cacheKey, { promise, timestamp: now });
+
+  // Drop failed fetches so the next call retries instead of caching the error
+  promise.catch(() => {
+    if (cache.get(cacheKey)?.promise === promise) {
+      cache.delete(cacheKey);
+    }
+  });
+
+  return promise;
+}
+
+/** Remove a cached entry (all param variants if no params given). */
+export function invalidateCache(key: string, params: unknown = null): void {
+  if (params !== null) {
+    cache.delete(`${key}:${JSON.stringify(params)}`);
+    return;
+  }
+  cache.delete(key);
+  for (const cacheKey of cache.keys()) {
+    if (cacheKey.startsWith(`${key}:`)) {
+      cache.delete(cacheKey);
+    }
+  }
+}