Rework cache middleware to use in-memory cache, remove ExpiringCache module

src/middleware/cache.ts

@@ -1,26 +1,30 @@
 import { Debug, type MiddlewareHandler } from '@/deps.ts';
-import ExpiringCache from '@/utils/expiring-cache.ts';
 
 const debug = Debug('ditto:middleware:cache');
 
-export const cache = (options: {
-  cacheName: string;
-  expires?: number;
-}): MiddlewareHandler => {
+interface CacheOpts {
+  expires: number;
+}
+
+/** In-memory cache middleware. */
+export const cache = (opts: CacheOpts): MiddlewareHandler => {
+  let response: Response | undefined;
+  let expires = Date.now() + opts.expires;
+
   return async (c, next) => {
-    const key = c.req.url.replace('http://', 'https://');
-    const cache = new ExpiringCache(await caches.open(options.cacheName));
-    const response = await cache.match(key);
-    if (!response) {
+    if (!response || (Date.now() > expires)) {
       debug('Building cache for page', c.req.url);
+      expires = Date.now() + opts.expires;
+
       await next();
-      const response = c.res.clone();
-      if (response.status < 500) {
-        await cache.putExpiring(key, response, options.expires ?? 0);
+
+      const res = c.res.clone();
+      if (res.status < 500) {
+        response = res;
       }
     } else {
       debug('Serving page from cache', c.req.url);
-      return response;
+      return response.clone();
     }
   };
 };