From 2a18b4b1a88e888dcaf8072ad33fca5758641f2c Mon Sep 17 00:00:00 2001
From: canglan <admin@sea-studio.top>
Date: Mon, 13 Jul 2026 04:18:52 +0800
Subject: [PATCH] perf: cache config.json reads by mtime, reduce sync I/O

---
 backend/db.js | 13 +++++++++----
 1 file changed, 9 insertions(+), 4 deletions(-)

diff --git a/backend/db.js b/backend/db.js
index 2f97464..4a9cd0d 100644
--- a/backend/db.js
+++ b/backend/db.js
@@ -6,12 +6,17 @@ const crypto = require('crypto');
 const CONFIG_PATH = path.join(__dirname, '..', 'data', 'config.json');
 
 let pool = null;
+let _configCache = null;
+let _configMtime = 0;
 
 function getConfig() {
-  if (fs.existsSync(CONFIG_PATH)) {
-    return JSON.parse(fs.readFileSync(CONFIG_PATH, 'utf-8'));
-  }
-  return null;
+  try {
+    const stat = fs.statSync(CONFIG_PATH);
+    if (_configCache && stat.mtimeMs === _configMtime) return _configCache;
+    _configCache = JSON.parse(fs.readFileSync(CONFIG_PATH, 'utf-8'));
+    _configMtime = stat.mtimeMs;
+    return _configCache;
+  } catch { return null; }
 }
 
 function saveConfig(cfg) {