Files
gemini-nexus/.agent/skills/vercel-react-best-practices/rules/js-cache-storage.md
AngeloooooandDraculabo 8ed4593f73 Refactor Gemini model display: filter old versions, group low/high pкo, and improve naming (#114)
* Refactor Gemini model display: filter old versions, group low/high pro, and improve naming

* Fix potential negative minutes and refine Gemini 3 Pro grouping logic based on PR feedback

* The account change process has been sped up

* Address PR review: enhance error message and parameterize polling interval in process handler

* Address PR review: fix potential race condition in database backup logic

* fix: prevent renderer white screen and harden sentry gating

* feat:  localize model labels

* chore: enable hoisted node-linker

* chore: ignore .agent/.claude/.codex in prettier

---------

Co-authored-by: Draculabo <[email protected]>
2026-02-19 19:37:30 +08:00

1.6 KiB

title, impact, impactDescription, tags
title impact impactDescription tags
Cache Storage API Calls LOW-MEDIUM reduces expensive I/O javascript, localStorage, storage, caching, performance

Cache Storage API Calls

localStorage, sessionStorage, and document.cookie are synchronous and expensive. Cache reads in memory.

Incorrect (reads storage on every call):

function getTheme() {
  return localStorage.getItem('theme') ?? 'light';
}
// Called 10 times = 10 storage reads

Correct (Map cache):

const storageCache = new Map<string, string | null>();

function getLocalStorage(key: string) {
  if (!storageCache.has(key)) {
    storageCache.set(key, localStorage.getItem(key));
  }
  return storageCache.get(key);
}

function setLocalStorage(key: string, value: string) {
  localStorage.setItem(key, value);
  storageCache.set(key, value); // keep cache in sync
}

Use a Map (not a hook) so it works everywhere: utilities, event handlers, not just React components.

Cookie caching:

let cookieCache: Record<string, string> | null = null;

function getCookie(name: string) {
  if (!cookieCache) {
    cookieCache = Object.fromEntries(document.cookie.split('; ').map((c) => c.split('=')));
  }
  return cookieCache[name];
}

Important (invalidate on external changes):

If storage can change externally (another tab, server-set cookies), invalidate cache:

window.addEventListener('storage', (e) => {
  if (e.key) storageCache.delete(e.key);
});

document.addEventListener('visibilitychange', () => {
  if (document.visibilityState === 'visible') {
    storageCache.clear();
  }
});