silphius/app/react/components/client-ecs.js

import {LRUCache} from 'lru-cache';

import Ecs from '@/ecs/ecs.js';
import {withResolvers} from '@/util/promise.js';

const cache = new LRUCache({
  max: 128,
});

export default class ClientEcs extends Ecs {
  constructor(specification) {
    super(specification);
    [
    ].forEach((defaultSystem) => {
      const System = this.system(defaultSystem);
      if (System) {
        System.active = true;
      }
    });
  }
  async readAsset(uri) {
    if (!cache.has(uri)) {
      const {promise, resolve, reject} = withResolvers();
      cache.set(uri, promise);
      fetch(new URL(uri, window.location.origin))
        .then(async (response) => {
          resolve(response.ok ? response.arrayBuffer() : new ArrayBuffer(0));
        })
        .catch(reject);
    }
    return cache.get(uri);
  }
}