From b1fda3a1a59189fd6665c370cddfe74daa9038c8 Mon Sep 17 00:00:00 2001
From: saravanakumardb1 <saravanakumardb1@users.noreply.github.com>
Date: Thu, 19 Feb 2026 15:28:07 -0800
Subject: [PATCH] =?UTF-8?q?perf(local-llm):=20Sprint=205=20=E2=80=94=20req?=
 =?UTF-8?q?uest=20dedup=20+=20cache=20TTLs=20(P1,=20P2,=20P3)?=
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Performance fixes:
- P1: Add fetchingRef guard to fetchAll() — prevents duplicate requests
  from rapid Refresh button clicks or overlapping interval ticks
- P2: Add 5-minute TTL to staticCache (chip, GPU, brew packages) —
  previously cached indefinitely per server process, now refreshes
  after brew upgrades without requiring a restart
- P3: Add 60-second TTL cache for Ollama models disk usage (du command)
  — previously traversed ~/.ollama/models on every 15s refresh cycle,
  now reuses cached value for 60s
---
 .../dashboard/src/app/api/system/route.ts     | 21 +++++++++++++++----
 __LOCAL_LLMs/dashboard/src/app/page.tsx       |  4 ++++
 2 files changed, 21 insertions(+), 4 deletions(-)

diff --git a/__LOCAL_LLMs/dashboard/src/app/api/system/route.ts b/__LOCAL_LLMs/dashboard/src/app/api/system/route.ts
index 5d44624b..7e6b71bb 100644
--- a/__LOCAL_LLMs/dashboard/src/app/api/system/route.ts
+++ b/__LOCAL_LLMs/dashboard/src/app/api/system/route.ts
@@ -6,12 +6,17 @@ import os from 'os';
 const execAsync = promisify(exec);
 const execFileAsync = promisify(execFile);
 
-// Cache slow commands (chip, gpu, brew don't change during a session)
+// Cache slow commands with TTL
 let staticCache: {
   chip: string;
   gpu: string;
   brewPackages: Array<{ name: string; version: string }>;
+  ts: number;
 } | null = null;
+const STATIC_TTL = 5 * 60 * 1000; // 5 minutes
+
+let ollamaDiskCache: { value: number; ts: number } | null = null;
+const OLLAMA_DISK_TTL = 60 * 1000; // 60 seconds
 
 async function getChipInfo(): Promise<string> {
   try {
@@ -80,16 +85,24 @@ async function getBrewPackages(): Promise<Array<{ name: string; version: string
 }
 
 async function getStaticInfo() {
-  if (staticCache) return staticCache;
+  if (staticCache && Date.now() - staticCache.ts < STATIC_TTL) return staticCache;
   const [chip, gpu, brewPackages] = await Promise.all([
     getChipInfo(),
     getGpuInfo(),
     getBrewPackages(),
   ]);
-  staticCache = { chip, gpu, brewPackages };
+  staticCache = { chip, gpu, brewPackages, ts: Date.now() };
   return staticCache;
 }
 
+async function getCachedOllamaDiskUsage(): Promise<number> {
+  if (ollamaDiskCache && Date.now() - ollamaDiskCache.ts < OLLAMA_DISK_TTL)
+    return ollamaDiskCache.value;
+  const value = await getOllamaModelsDiskUsage();
+  ollamaDiskCache = { value, ts: Date.now() };
+  return value;
+}
+
 // macOS vm_stat gives accurate memory breakdown (os.freemem() excludes reclaimable cache)
 async function getAccurateMemory(): Promise<{
   total: number;
@@ -140,7 +153,7 @@ export async function GET() {
   const [staticInfo, disk, ollamaDisk, memory] = await Promise.all([
     getStaticInfo(),
     getDiskSpace(),
-    getOllamaModelsDiskUsage(),
+    getCachedOllamaDiskUsage(),
     getAccurateMemory(),
   ]);
 
diff --git a/__LOCAL_LLMs/dashboard/src/app/page.tsx b/__LOCAL_LLMs/dashboard/src/app/page.tsx
index 825dcae8..5b5f321a 100644
--- a/__LOCAL_LLMs/dashboard/src/app/page.tsx
+++ b/__LOCAL_LLMs/dashboard/src/app/page.tsx
@@ -68,6 +68,7 @@ export default function Dashboard() {
   const [modelfileData, setModelfileData] = useState<Record<string, string>>({});
   const responseRef = useRef<HTMLDivElement>(null);
   const abortRef = useRef<AbortController | null>(null);
+  const fetchingRef = useRef(false);
 
   const addToast = useCallback((message: string, type: Toast['type'] = 'info') => {
     const id = Date.now() + Math.random();
@@ -76,6 +77,8 @@ export default function Dashboard() {
   }, []);
 
   const fetchAll = useCallback(async () => {
+    if (fetchingRef.current) return;
+    fetchingRef.current = true;
     setLoading(true);
     const [oRes, wRes, sRes] = await Promise.allSettled([
       fetch('/api/ollama').then(r => r.json()),
@@ -87,6 +90,7 @@ export default function Dashboard() {
     if (sRes.status === 'fulfilled') setSystem(sRes.value);
     setLastRefresh(new Date());
     setLoading(false);
+    fetchingRef.current = false;
   }, []);
 
   useEffect(() => {