var t = new Date();
setInterval(function () {
  console.log(new Date() - t);
  t = new Date();
}, 100);

/** 加法 */
function accAdd(arg1, arg2) {
  var r1, r2, m;
  try {
    r1 = arg1.toString().split(".")[1].length;
  } catch (e) {
    r1 = 0;
  }
  try {
    r2 = arg2.toString().split(".")[1].length;
  } catch (e) {
    r2 = 0;
  }
  m = Math.pow(10, Math.max(r1, r2));
  return (arg1 * m + arg2 * m) / m;
}

router.afterEach((to, from) => {
  /** 累计所加载的资源，不包含当前页面 */
  let accumulatedRs = window.performance
    .getEntriesByType("resource")
    .map((item) => {
      let newItem = {
        name: item.name,
        duration: item.duration,
      };
      return newItem;
    });

  /** 存储中的 accumulatedRs */
  let storageRs = localStorage.accumulatedRs;
  let storageRsLength = 0;
  if (storageRs && storageRs.startsWith("[")) {
    // 刷新页面之前， accumulatedRs 会一直累加；刷新后， accumulatedRs 会被重置，所以会出现 storageRs 比 accumulatedRs 要多的情况
    if (JSON.parse(storageRs).length >= accumulatedRs.length) {
      storageRs = localStorage.accumulatedRs = "";
      storageRsLength = 0;
    } else {
      storageRsLength = JSON.parse(storageRs).length;
    }
  } else {
    storageRs = localStorage.accumulatedRs = "";
    storageRsLength = 0;
  }

  let loadTime = 0;
  let len = accumulatedRs.length - storageRsLength;
  for (let i = 0; i < len; i++) {
    const r = accumulatedRs.slice(-len)[i];
    loadTime = accAdd(loadTime, r.duration);
  }
  localStorage.accumulatedRs = JSON.stringify(accumulatedRs);
  let lastPage = router.resolve(from).href;
  console.log(`上个页面 = ${lastPage} --- 加载耗时 = ${loadTime.toFixed(2)}ms`);
});