> For the complete documentation index, see [llms.txt](https://shenjunhong.gitbook.io/blog/llms.txt). Markdown versions of documentation pages are available by appending `.md` to page URLs; this page is available as [Markdown](https://shenjunhong.gitbook.io/blog/chang-jian-zong-jie/bian-cheng-mao/xing-neng-pai-cha-yu-you-hua-shi-jian.md).

# 性能排查与优化实践

性能排查与优化实践

先说一下技术栈:React18 + Mobx + Antd

在看一下 LightHouse 的评分效果

![](/files/HqCwgoHJ1dGJ324BdfRu)

优化重点：

1. memo useMemo useCallback
2. 剔除不规范写法（重复在 store 与 useEffect）

优化后的效果： ![](/files/g6obabwknYH227vVKaJn)

排查方案：

1. dev-tools 分析 profile 效果

profile 是在

以前的渲染优化方式：

1. 优化

```js
import React from "react";
import { is } from "immutable";
export default class extends React.Component {
  shouldComponentUpdate(nextProps = {}, nextState = {}) {
    if (
      Object.keys(this.props).length !== Object.keys(nextProps).length ||
      Object.keys(this.state).length !== Object.keys(nextState).length
    ) {
      return true;
    }
    for (const key in nextProps) {
      if (!is(this.props[key], nextProps[key])) {
        return true;
      }
    }
    for (const key in nextState) {
      if (!is(this.state[key], nextState[key])) {
        return true;
      }
    }
    return false;
  }
}
```

2. 优化

```js
// customEquals: lodash.isEqual、Immutable.is、dequal.deepEqual 等；
const useOriginalCopy = (value) => {
  const copy = React.useRef();
  const diffRef = React.useRef(0);
  if (!customEquals(value, copy.current)) {
    copy.current = value;
    diffRef.current += 1;
  }
  return [diffRef.current];
};
```


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