Load lookup database only once.

lib/request.js

@@ -12,6 +12,8 @@ import {
   MOBILE_SCREEN_WIDTH,
 } from './constants';
 
+let lookup;
+
 export function getIpAddress(req) {
   // Cloudflare
   if (req.headers['cf-connecting-ip']) {
@@ -61,7 +63,9 @@ export async function getCountry(req, ip) {
   }
 
   // Database lookup
-  const lookup = await maxmind.open(path.resolve('./public/geo/GeoLite2-Country.mmdb'));
+  if (!lookup) {
+    lookup = await maxmind.open(path.resolve('./public/geo/GeoLite2-Country.mmdb'));
+  }
 
   const result = lookup.get(ip);