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Caching Patterns with Strata Storage

A cache entry should have a key, a freshness limit, and a way to invalidate it when the source changes. Strata Storage supplies key-value operations and TTL; your application decides when it is safe to use a cached value.

Cache-Aside Pattern​

import { defineStorage } from 'strata-storage';

const cache = defineStorage({
  defaultStorages: ['indexedDB', 'localStorage', 'memory'],
});

async function getCached<T>(
  key: string,
  fetchFresh: () => Promise<T>,
  ttl: number,
): Promise<T> {
  const cached = await cache.get<T>(key);
  if (cached !== null) return cached;

  const value = await fetchFresh();
  await cache.set(key, value, { ttl });
  return value;
}

defineStorage() registers the web adapters. The first available defaultStorages entry becomes the default. An expired key reads as null; the next request calls fetchFresh.

Invalidation​

await cache.remove('product:123');

const keys = await cache.keys(/^product:/);
for (const key of keys) {
  await cache.remove(key);
}

If a single Strata instance has several registered adapters, pass { storage: 'indexedDB' } to each call when you need to target exactly that backend. A key's namespace and physical prefix are separate from a cache invalidation pattern.

Cache API Adapter​

The Strata cache adapter uses browser Cache storage for string-keyed, JSON-serializable values. It does not round-trip native Request or Response objects. Use the browser Cache API directly for HTTP request/response matching, or keep the response body as a serializable value in Strata.

await cache.set('api:/items', { items: ['one', 'two'] }, {
  storage: 'cache',
  ttl: 300_000,
});

The adapter is available in a supported browser page with window.caches; the current implementation does not run in a service worker global scope.

Platform Limits​

The package is client-side key-value storage. It does not provide a shared server cache or a Node SQLite backend. In a Capacitor app, register native adapters before selecting sqlite or preferences; see the Capacitor guide.

See Also​