performanceObserver.observe(options)

• options <Object>
  • type <string> 单个 <PerformanceEntry> 类型。如果已经指定了 entryTypes，则不能再提供此项。
  • entryTypes <string[]> 一个字符串数组，用于识别观察者感兴趣的 <PerformanceEntry> 实例类型。如果未提供，将抛出错误。
  • buffered <boolean> 如果为 true，观察者回调将使用全局 PerformanceEntry 缓冲条目的列表调用。如果为 false，则只会将时间点之后创建的 PerformanceEntry 发送给观察者回调。默认值: false。

将 <PerformanceObserver> 实例订阅到新 <PerformanceEntry> 实例的通知，这些实例可以通过 options.entryTypes 或 options.type 标识：

【Subscribes the <PerformanceObserver> instance to notifications of new <PerformanceEntry> instances identified either by options.entryTypes or options.type:】

import { performance, PerformanceObserver } from 'node:perf_hooks';

const obs = new PerformanceObserver((list, observer) => {
  // Called once asynchronously. `list` contains three items.
});
obs.observe({ type: 'mark' });

for (let n = 0; n < 3; n++)
  performance.mark(`test${n}`);const {
  performance,
  PerformanceObserver,
} = require('node:perf_hooks');

const obs = new PerformanceObserver((list, observer) => {
  // Called once asynchronously. `list` contains three items.
});
obs.observe({ type: 'mark' });

for (let n = 0; n < 3; n++)
  performance.mark(`test${n}`);拷贝