unpkg/server/middleware/utils/createCache.js

const db = require('../../RedisClient')

function createCache(keyPrefix) {
  function createKey(key) {
    return keyPrefix + '-' + key
  }

  function set(key, value, expiry, callback) {
    db.setex(createKey(key), expiry, JSON.stringify(value), callback)
  }

  function get(key, callback) {
    db.get(createKey(key), function (error, value) {
      callback(error, value && JSON.parse(value))
    })
  }

  function del(key, callback) {
    db.del(createKey(key), callback)
  }

  return {
    set,
    get,
    del
  }
}

module.exports = createCache