ruud/src/cache.js

the player who serves

import { SESSION_DURATION } from './session.js';

const values = {};
const expirations = {}
const timeouts = {};
const statics = {};

const queue = [];

// ---> cache method exposed in context

const cache = ({ url }, ttl, customPath) => queue.push([url, ttl, customPath]);

// --->

cache.get = ({ url, relativeUrl, session }) => {
  const path = relativeUrl || url;
  statics[path] && session.static.set(statics[path]);
  return values[path];
};

// ---> store expirations: set matching ttl in relation to main route

cache.update = (path, payload, minutes = SESSION_DURATION) => {
  const ttl = minutes * 1000 * 60;
  values[path] = payload;
  expirations[path] = +new Date + ttl;
  clearTimeout(timeouts[path]);
  timeouts[path] = setTimeout(() => {
    delete values[path];
    delete expirations[path];
    delete timeouts[path];
  }, ttl);

  return payload;
};

cache.set = ({ url, relative, relativeUrl, relativeRoot }, payload) => {

  // ---> if route is cached and file is a relative reference

  if (relative) {
    const cachedRoute = `/${relative}`;
    const expires = expirations[cachedRoute];
    if (!expires) return;
    const ttl = (expires - new Date) / 1000 / 60;
    return cache.update(relativeUrl, payload, ttl);
  }

  // ---> handle queue

  for (const item of queue) {
    const [cachePath, ttl, customPath] = item;
    if (url === cachePath) {
      queue.splice(queue.indexOf(item), 1);
      const path = customPath || cachePath;

      // store root path for files cached relative to parent folder
      statics[path] = relativeRoot;

      return cache.update(path, payload, ttl);
    }
  }

  return payload;
};

export default cache;