홈, 갤러리, 캐시 설정, 썸네일 설정 페이지에서의 네트워크 호출 최적화

src/lib/modules/filesystem/internal.svelte.ts

@@ -17,7 +17,7 @@ export class FilesystemCache<K, V extends RV, RV = V> {
     loader(!info, (loadedInfo) => {
       if (!loadedInfo) return;
 
-      let info = this.map.get(key)!;
+      const info = this.map.get(key)!;
       if (info instanceof Promise) {
         const state = $state(loadedInfo);
         this.map.set(key, state as V);
@@ -30,6 +30,54 @@ export class FilesystemCache<K, V extends RV, RV = V> {
 
     return info ?? promise;
   }
+
+  async bulkGet(
+    keys: Set<K>,
+    loader: (keys: Map<K, boolean>, resolve: (values: Map<K, RV>) => void) => void,
+  ) {
+    const states = new Map<K, V>();
+    const promises = new Map<K, Promise<V>>();
+    const resolvers = new Map<K, (value: V) => void>();
+
+    keys.forEach((key) => {
+      const info = this.map.get(key);
+      if (info instanceof Promise) {
+        promises.set(key, info);
+      } else if (info) {
+        states.set(key, info);
+      } else {
+        const { promise, resolve } = Promise.withResolvers<V>();
+        this.map.set(key, promise);
+        promises.set(key, promise);
+        resolvers.set(key, resolve);
+      }
+    });
+
+    loader(
+      new Map([
+        ...states.keys().map((key) => [key, false] as const),
+        ...resolvers.keys().map((key) => [key, true] as const),
+      ]),
+      (loadedInfos) =>
+        loadedInfos.forEach((loadedInfo, key) => {
+          const info = this.map.get(key)!;
+          const resolve = resolvers.get(key);
+          if (info instanceof Promise) {
+            const state = $state(loadedInfo);
+            this.map.set(key, state as V);
+            resolve?.(state as V);
+          } else {
+            Object.assign(info, loadedInfo);
+            resolve?.(info);
+          }
+        }),
+    );
+
+    const newStates = await Promise.all(
+      promises.entries().map(async ([key, promise]) => [key, await promise] as const),
+    );
+    return new Map([...states, ...newStates]);
+  }
 }
 
 export const decryptDirectoryMetadata = async (