面试题：Solid.js响应式状态在复杂应用场景下的持久化存储优化

设计思路

状态管理：使用Solid.js的响应式系统来管理应用的状态。将不同类型的状态（用户信息、用户偏好设置、购物车数据等）分别定义为独立的响应式变量。
IndexedDB封装：创建一个封装IndexedDB操作的模块，提供异步的读取和写入方法。这个模块负责处理IndexedDB的打开、事务管理、数据操作等细节。
加载顺序：在应用加载时，按照特定顺序依次从IndexedDB中读取每个状态。可以使用async/await或者Promise链式调用确保顺序性。
状态更新同步：在状态更新时，使用Solid.js的响应式机制，在状态变化后触发同步到IndexedDB的操作。为了避免性能问题，可以采用防抖（Debounce）或节流（Throttle）技术。
数据竞争处理：利用Promise的特性，确保每次IndexedDB操作都是顺序执行，避免多个操作同时修改数据导致的数据竞争。

关键代码逻辑

IndexedDB封装模块

const indexedDB = window.indexedDB;

const dbPromise = new Promise((resolve, reject) => {
  const request = indexedDB.open('myAppDB', 1);

  request.onupgradeneeded = (event) => {
    const db = event.target.result;
    const objectStore = db.createObjectStore('userInfo', { keyPath: 'id' });
    const objectStore2 = db.createObjectStore('userPreferences', { keyPath: 'id' });
    const objectStore3 = db.createObjectStore('cartData', { keyPath: 'id' });
  };

  request.onsuccess = (event) => {
    resolve(event.target.result);
  };

  request.onerror = (event) => {
    reject(event.target.error);
  };
});

export const getFromIndexedDB = async (storeName, key) => {
  const db = await dbPromise;
  return new Promise((resolve, reject) => {
    const transaction = db.transaction(storeName);
    const objectStore = transaction.objectStore(storeName);
    const request = objectStore.get(key);
    request.onsuccess = (event) => {
      resolve(event.target.result);
    };
    request.onerror = (event) => {
      reject(event.target.error);
    };
  });
};

export const putToIndexedDB = async (storeName, data) => {
  const db = await dbPromise;
  return new Promise((resolve, reject) => {
    const transaction = db.transaction(storeName, 'readwrite');
    const objectStore = transaction.objectStore(storeName);
    const request = objectStore.put(data);
    request.onsuccess = (event) => {
      resolve(event.target.result);
    };
    request.onerror = (event) => {
      reject(event.target.error);
    };
  });
};

应用加载时状态恢复

import { createSignal } from 'solid-js';
import { getFromIndexedDB } from './indexedDBUtils';

const [userInfo, setUserInfo] = createSignal(null);
const [userPreferences, setUserPreferences] = createSignal(null);
const [cartData, setCartData] = createSignal(null);

const loadStates = async () => {
  try {
    const userInfoData = await getFromIndexedDB('userInfo', 'user1');
    setUserInfo(userInfoData);
    const userPreferencesData = await getFromIndexedDB('userPreferences', 'user1');
    setUserPreferences(userPreferencesData);
    const cartDataData = await getFromIndexedDB('cartData', 'user1');
    setCartData(cartDataData);
  } catch (error) {
    console.error('Error loading states:', error);
  }
};

loadStates();

状态更新同步

import { createSignal, createEffect } from 'solid-js';
import { putToIndexedDB } from './indexedDBUtils';

const [userInfo, setUserInfo] = createSignal(null);

createEffect(() => {
  const debounceTimer = setTimeout(() => {
    const currentUserInfo = userInfo();
    if (currentUserInfo) {
      putToIndexedDB('userInfo', currentUserInfo).catch(console.error);
    }
  }, 300); // 防抖时间300毫秒
  return () => clearTimeout(debounceTimer);
});

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面试题：Solid.js响应式状态在复杂应用场景下的持久化存储优化

知识考点

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设计思路

关键代码逻辑