perf: Use cache for all remote resources

backend/src/utils/resource-cache.js

@@ -0,0 +1,47 @@
+import $ from '@/core/app';
+import { CACHE_EXPIRATION_TIME_MS, RESOURCE_CACHE_KEY } from '@/constants';
+
+class ResourceCache {
+    constructor(expires) {
+        this.expires = expires;
+        if (!$.read(RESOURCE_CACHE_KEY)) {
+            $.write('{}', RESOURCE_CACHE_KEY);
+        }
+        this.resourceCache = JSON.parse($.read(RESOURCE_CACHE_KEY));
+        this._cleanup();
+    }
+
+    _cleanup() {
+        // clear obsolete cached resource
+        let clear = false;
+        Object.entries(this.resourceCache).forEach((entry) => {
+            const [id, updated] = entry;
+            if (new Date().getTime() - updated > this.expires) {
+                $.delete(`#${id}`);
+                delete this.resourceCache[id];
+                clear = true;
+            }
+        });
+        if (clear) this._persist();
+    }
+
+    _persist() {
+        $.write(JSON.stringify(this.resourceCache), RESOURCE_CACHE_KEY);
+    }
+
+    get(id) {
+        const updated = this.resourceCache[id];
+        if (updated && new Date().getTime() - updated <= this.expires) {
+            return $.read(`#${id}`);
+        }
+        return null;
+    }
+
+    set(id, value) {
+        this.resourceCache[id] = new Date().getTime();
+        this._persist();
+        $.write(value, `#${id}`);
+    }
+}
+
+export default new ResourceCache(CACHE_EXPIRATION_TIME_MS);