website: fixes

website/scripts/utils/cache.js

@@ -6,27 +6,33 @@ export function createMapCache(maxSize = 100) {
   /** @type {Map<string, V>} */
   const map = new Map();
 
+  /** @param {string} key @param {V} value */
+  const set = (key, value) => {
+    if (map.size >= maxSize && !map.has(key)) {
+      const first = map.keys().next().value;
+      if (first !== undefined) map.delete(first);
+    }
+    map.set(key, value);
+  };
+
   return {
     /** @param {string} key @returns {V | undefined} */
-    get(key) {
-      return map.get(key);
-    },
+    get: (key) => map.get(key),
     /** @param {string} key @returns {boolean} */
-    has(key) {
-      return map.has(key);
-    },
-    /** @param {string} key @param {V} value */
-    set(key, value) {
-      if (map.size >= maxSize && !map.has(key)) {
-        const first = map.keys().next().value;
-        if (first !== undefined) map.delete(first);
-      }
-      map.set(key, value);
+    has: (key) => map.has(key),
+    set,
+    /** @param {string} key @param {() => Promise<V>} fetcher @returns {Promise<V>} */
+    async fetch(key, fetcher) {
+      const hit = map.get(key);
+      if (hit !== undefined) return hit;
+      const value = await fetcher();
+      set(key, value);
+      return value;
     },
   };
 }
 
 /**
  * @template V
- * @typedef {{ get: (key: string) => V | undefined, has: (key: string) => boolean, set: (key: string, value: V) => void }} MapCache
+ * @typedef {ReturnType<typeof createMapCache<V>>} MapCache
  */