TypeScript实战篇 - TS实战： 服务层开发 - 完整的聊天服务

目录

huatian-svc/src/main.ts

huatian-svc/src/context/ChatContext.ts

huatian-svc/src/ChatSession.ts

huatian-svc/src/service/ChatIDService.ts

huatian-svc/src/dao/DB.ts

huatian-svc/src/dao/Dao.ts

huatian-svc/src/dao/create_db.ts

---

huatian-svc/src/main.ts

import express, {NextFunction,Request,Response
} from "express";
// 安装cookie-parser: npm add cookie-parser
import cookieParser from "cookie-parser";
import { AccountContext } from "./context/AccountContext";
import { Token } from "./dao/Token";
import { ChatContext } from "./context/ChatContext";
import { Message } from "@huatian/model";
// 创建一个服务
const app = express()
// cookie功能,整理好cookie,req.cookies
app.use(cookieParser())
// 登录后的数据类
type LoggedInRequest = Request & { uid: number }
async function sendStdResponse<T>(res: Response, f: T)
async function sendStdResponse(res: Response, f: Promise<any>)
async function sendStdResponse(res: Response, f: () => Promise<any>)
async function sendStdResponse(res: Response, f: any) {try {let data = typeof f === 'function' ? f() : fif (data instanceof Promise) {data = await data}res.send({success: true,data})} catch (ex: any) {console.error(ex)res.status(500).send({success: false,message: ex.toString()})}
}
// token
async function token(req: Request & { uid: number },// req 是带着uid的res: Response,next: NextFunction
) {// tokenHash~=sessionidconst tokenHash = req.cookies["x-token"] as stringconst token = Token.getInstance()const tokenObject = token.getToken(tokenHash)if (tokenObject === null) {res.status(401).send({success: false})return}req.uid = tokenObject.uidnext()
}
app.get('/foo', token, (req: Request & { uid: number }, res) => {res.send(req.uid + '-ok')
})
// 登录接口,json传参【express.json()解析json】
app.post('/token', express.json(), async (req, res) => {const { uname, pwd } = req.bodyconst account = AccountContext.getInstance()const user = await account.veritfy(uname, pwd)console.log(uname, pwd, user.getId())const token = Token.getInstance()// 刷新tokenconst tokenObject = token.refreshToken(user.getId())res.cookie("x-token", tokenObject.token)sendStdResponse(res, "ok")
})
// ==================聊天接口相关==============================
// 名词命名接口
app.post("/message", token, express.json(), async (req: LoggedInRequest, res) => {const uid = req.uid// 先拿到场景const chatContext = ChatContext.getInstance()// 返回,最后发送的信息sendStdResponse(res, async () => {return await chatContext.send(uid, req.body as Message)})
})
// 请求聊天内容
app.get('/message', token, async (req: LoggedInRequest, res) => {const uid = req.uid// 最后一条id,不传就读所有const lastId = parseInt(req.query.last_id as string) || 0console.log({ uid, lastId })const chatContext = ChatContext.getInstance()sendStdResponse(res, () => {return chatContext.read(uid, lastId)})
})
// =================================================
// 监听一个6001端口号的服务
app.listen(6001, () => {console.log('listen at 6001')
})

huatian-svc/src/context/ChatContext.ts

// 聊天场景
import { Message } from "@huatian/model"
import { UserRepository } from "../repo/UserRepository"
import { ChatIDService } from "../service/ChatIDService"
// 服务当中的聊天场景【处理网络，处理存储，不处理模型】
export class ChatContext {// 单例private static inst = new ChatContext()private repo = UserRepository.getInstance()// 获取单例public static getInstance() {return ChatContext.inst}// 发送public async send(uid: number, msg: Message) {// Message需要一个服务 生成idconst sentMsg = { ...msg }const toReceiveMsg = { ...msg }sentMsg.id = await ChatIDService.getInstance().getId()toReceiveMsg.id = await ChatIDService.getInstance().getId()msg.from = uid // 覆盖一下fromconst from = this.repo.getUser(msg.from)const to = this.repo.getUser(msg.to)const session = from.chat().createChatSession(to)// 用session的聊天方法session.chat(sentMsg, toReceiveMsg)// 告诉客户端最新发送的消息是哪条return sentMsg.id}public read(uid: number, lastId: number) {// 用户仓库中拿出用户const user = this.repo.getUser(uid)// 用lastId拿所有未读 消息return user.chat().unReadMessage(lastId)}
}

huatian-svc/src/ChatSession.ts

import { Message } from "./Message";
import { User } from "./User";
// 聊天会话模型
export class ChatSession {private from: Userprivate to: Userpublic constructor(from: User, to: User) {this.from = fromthis.to = to}// 此处修改为收发个一条消息public chat(sentMsg: Message, roReceiveMsg: Message) { // 会话中可以聊天this.from.chat().send(sentMsg) // 用户发送一条消息this.to.chat().receive(roReceiveMsg) // 用户接收一条消息}
}

huatian-svc/src/service/ChatIDService.ts

// 生成消息id的服务
import { ChatIDSetDao } from "../dao/Dao"
import { DB } from "../dao/DB"
// Message生成id的服务
const STEP = 100000
export class ChatIDService {// 初始化时间端的单例写法private static inst: ChatIDService = new ChatIDService()private id_base: number = 0private id_start: number = 0public static getInstance(): ChatIDService {return ChatIDService.inst}/*** 每次拿到的是一个集合的ID* 比如0~99999*/private async requestIdSet() {if (this.id_base >= this.id_start &&this.id_base < this.id_start + STEP) {return}const sequelize = DB.getSequelize()const transaction = await sequelize.transaction()try {// 0---->100000// 0----->100000// 上锁之后要等前一条完成,才能继续执行这一条// 拿表最后一条数据const lastRecord = await ChatIDSetDao.findOne({order: [["id", "desc"]], // 根据id倒序,就是最后一条记录lock: transaction.LOCK.UPDATE // 锁住,不能同时访问})const startNumber = lastRecord? lastRecord.getDataValue("start") + 100000: 0await ChatIDSetDao.create({app: "test", // 临时start: startNumber})// 恢复一下值this.id_start = startNumberthis.id_base = startNumber} catch (ex) {console.error(ex)transaction.rollback()// 回滚}}public async getId() {await this.requestIdSet()return this.id_base++}
}

huatian-svc/src/dao/DB.ts

// 表,负责连接的
// node端比较好用的数据工具
import path from "path";
import { Sequelize } from "sequelize";
export class DB {static sequelize: Sequelize// 初始化时间较长的单例写法static getSequelize() {if (!DB.sequelize) {DB.sequelize = new Sequelize({dialect: "sqlite", // 数据库类型,上线后替换成mysqlstorage: path.resolve(__dirname, "mydb.db")})}return DB.sequelize}
}

huatian-svc/src/dao/Dao.ts

// 创建一张表
import { Model, Optional, DataTypes } from "sequelize";
import { DB } from "./DB";
// 聊天集合的一个分类
interface ChatIDSetAttributes {id: number,app: string,// app,集群,应用名称start: number
}
export class ChatIDSetDao extends Model<ChatIDSetAttributes,Optional<ChatIDSetAttributes, "id">
>{ }
ChatIDSetDao.init({id: {type: DataTypes.BIGINT, // INTEGER;数量很多的话用,BIGINT,几十亿数据 autoIncrement: true,// 自增字段primaryKey: true// 主键},app: {type: DataTypes.STRING(20),allowNull: false // 不允许null},start: {type: DataTypes.BIGINT,allowNull: false // 不允许null}}, {sequelize: DB.getSequelize(),tableName: "id_set" // 表的名称
}
)

huatian-svc/src/dao/create_db.ts

// 初始化表的脚本
import { ChatIDSetDao } from "./Dao";
//sync自动创建表,force: true存在也创建
ChatIDSetDao.sync({ force: true })