关于前端:浏览器storage封装

/***
 * title: storage.js
 * Author: Gaby
 * Email: xxx@126.com
 * Time: 2022/6/1 17:30
 * last: 2022/6/2 17:30
 * Desc: 对存储的简略封装
 */
 
import CryptoJS from 'crypto-js';

// 十六位十六进制数作为密钥
const SECRET_KEY = CryptoJS.enc.Utf8.parse("3333e6e143439161");
// 十六位十六进制数作为密钥偏移量
const SECRET_IV = CryptoJS.enc.Utf8.parse("e3bbe7e3ba84431a");

// 类型 window.localStorage,window.sessionStorage,
const config = {
    type: 'localStorage', // 本地存储类型 sessionStorage
    prefix: 'SDF_0.0.1', // 名称前缀 倡议：我的项目名 + 我的项目版本
    expire: 1, // 过期工夫 单位：秒
    isEncrypt: true // 默认加密 为了调试不便, 开发过程中能够不加密
}

// 判断是否反对 Storage
export const isSupportStorage = () => {return (typeof (Storage) !== "undefined") ? true : false
}

// 设置 setStorage
export const setStorage = (key, value, expire = 0) => {if (value === '' || value === null || value === undefined) {value = null;}

    if (isNaN(expire) || expire < 0) throw new Error("Expire must be a number");

    expire = (expire ? expire : config.expire) * 1000;
    let data = {
        value: value, // 存储值
        time: Date.now(), // 存值工夫戳
        expire: expire // 过期工夫
    }
    
    const encryptString = config.isEncrypt 
    ? encrypt(JSON.stringify(data))
    : JSON.stringify(data);
    
    window[config.type].setItem(autoAddPrefix(key), encryptString);
}

// 获取 getStorage
export const getStorage = (key) => {key = autoAddPrefix(key);
    // key 不存在判断
    if (!window[config.type].getItem(key) || JSON.stringify(window[config.type].getItem(key)) === 'null') {return null;}

    // 优化 继续应用中续期
    const storage = config.isEncrypt 
    ? JSON.parse(decrypt(window[config.type].getItem(key))) 
    : JSON.parse(window[config.type].getItem(key));
    
    let nowTime = Date.now();

    // 过期删除
    if (storage.expire && config.expire * 6000 < (nowTime - storage.time)) {removeStorage(key);
        return null;
    } else {
        // 未过期期间被调用 则主动续期 进行保活
        setStorage(autoRemovePrefix(key), storage.value);
        return storage.value;
    }
}

// 是否存在 hasStorage
export const hasStorage = (key) => {key = autoAddPrefix(key);
    let arr = getStorageAll().filter((item)=>{return item.key === key;})
    return arr.length ? true : false;
}

// 获取所有 key
export const getStorageKeys = () => {let items = getStorageAll()
    let keys = []
    for (let index = 0; index < items.length; index++) {keys.push(items[index].key)
    }
    return keys
}

// 依据索引获取 key
export const getStorageForIndex = (index) => {return window[config.type].key(index)
}

// 获取 localStorage 长度
export const getStorageLength = () => {return window[config.type].length
}

// 获取全副 getAllStorage
export const getStorageAll = () => {let len = window[config.type].length // 获取长度
    let arr = new Array() // 定义数据集
    for (let i = 0; i < len; i++) {
        // 获取 key 索引从 0 开始
        let getKey = window[config.type].key(i)
        // 获取 key 对应的值
        let getVal = window[config.type].getItem(getKey)
        // 放进数组
        arr[i] = {'key': getKey, 'val': getVal,}
    }
    return arr
}

// 删除 removeStorage
export const removeStorage = (key) => {window[config.type].removeItem(autoAddPrefix(key));
}

// 清空 clearStorage
export const clearStorage = () => {window[config.type].clear();}

// 名称前主动增加前缀
const autoAddPrefix = (key) => {
    const prefix = config.prefix ? config.prefix + '_' : '';
    return  prefix + key;
}

// 移除已增加的前缀
const autoRemovePrefix = (key) => {
    const len = config.prefix ? config.prefix.length+1 : '';
    return key.substr(len)
    // const prefix = config.prefix ? config.prefix + '_' : '';
    // return  prefix + key;
}

/**
 * 加密办法
 * @param data
 * @returns {string}
 */
const encrypt = (data) => {if (typeof data === "object") {
        try {data = JSON.stringify(data);
        } catch (error) {console.log("encrypt error:", error);
        }
    }
    const dataHex = CryptoJS.enc.Utf8.parse(data);
    const encrypted = CryptoJS.AES.encrypt(dataHex, SECRET_KEY, {
        iv: SECRET_IV,
        mode: CryptoJS.mode.CBC,
        padding: CryptoJS.pad.Pkcs7
    });
    return encrypted.ciphertext.toString();}

/**
 * 解密办法
 * @param data
 * @returns {string}
 */
const decrypt = (data) => {const encryptedHexStr = CryptoJS.enc.Hex.parse(data);
    const str = CryptoJS.enc.Base64.stringify(encryptedHexStr);
    const decrypt = CryptoJS.AES.decrypt(str, SECRET_KEY, {
        iv: SECRET_IV,
        mode: CryptoJS.mode.CBC,
        padding: CryptoJS.pad.Pkcs7
    });
    const decryptedStr = decrypt.toString(CryptoJS.enc.Utf8);
    return decryptedStr.toString();}