1、简介

1.1 node

Node.js 是一个开源的、跨平台的 JavaScript 运行时环境。

Node.js 是一个开源和跨平台的 JavaScript 运行时环境。 它是几乎任何类型项目的流行工具！

Node.js 在浏览器之外运行 V8 JavaScript 引擎（Google Chrome 的内核）。 这使得 Node.js 非常高效。

Node.js 应用在单个进程中运行，无需为每个请求创建新线程。 Node.js 在其标准库中提供了一组异步 I/O 原语，以防止 JavaScript 代码阻塞，并且通常，Node.js 中的库是使用非阻塞范例编写的，这使得阻塞行为成为异常而不是常态。

1.2 Protobuf

Protobuf 是一种用于 序列化 和 反序列化 对象的格式规范（rpc 通信协议）。

Protobuf 与 非结构化格式（如 JSON、XML）最大的区别在于，你必须为 protobufs 定义数据类型，最常用的方式是定义 .proto 文件。

Google Protocol Buffer( 简称 Protobuf) 是 Google 公司内部的混合语言数据标准，目前已经正在使用的有超过 48,162 种报文格式定义和超过 12,183 个 .proto 文件。他们用于 RPC 系统和持续数据存储系统。

Google Protocol Buffers 是一种轻便高效的结构化数据存储格式，可以用于结构化数据串行化，或者说序列化。它很适合做数据存储或 RPC 数据交换格式。可用于通讯协议、数据存储等领域的语言无关、平台无关、可扩展的序列化结构数据格式。目前提供了 C++、Java、Python 三种语言的 API（即时通讯网注：Protobuf官方工程主页上显示的已支持的开发语言多达10种，分别有：C++、Java、Python、Objective-C、C#、JavaNano、JavaScript、Ruby、Go、PHP，基本上主流的语言都已支持.

2、下载和安装

2.1 node

https://nodejs.org/zh-cn

https://nodejs.org/zh-cn/download

2.2 Protobuf

https://github.com/protocolbuffers/protobuf
https://github.com/protobufjs/protobuf.js
https://protobufjs.github.io/protobuf.js/

protobuf.js是一个纯JavaScript实现，支持Node.js和浏览器的TypeScript，它容易使用速度快速，可以直接反射.proto文件，不需要生成任何文件。

protobuf.js是基于ByteBuffer.js的Protocol Buffers纯JavaScript实现，主要功能是解析.proto文件，构建Message类，编码解码。

2.2.1 安装

npm install protobufjs [--save --save-prefix=~]
npm i -g protobufjs# The command line utility lives in the protobufjs-cli package and must be installed separately:
npm install protobufjs-cli [--save --save-prefix=~]

2.2.2 工具

https://protobufjs.github.io/protobuf.js/#pbjs-for-javascript

#老版本
##使用pbjs命令将.proto文件转换为.js文件
./node_modules/protobufjs/bin/pbjs -t json msg.proto > msg.json## 使用pbjs命令将.proto文件转换为.json文件
./node_modules/protobufjs/bin/pbjs -t static_module -w commonjs -o msg.js msg.proto#新版本
npx pbjs  -t json message.proto --es6 "msg.js"
npx pbjs  -t json message.proto --ts "msg.ts" 

而在node端，也可以打包成js文件来处理。但node端是服务端环境了，完全可以允许.proto的存在，所以其实我们可以有优雅的使用方式：直接解析。

使用pbjs命令将.proto文件转换为.json文件:

./node_modules/protobufjs/bin/pbjs -t json msg.proto > msg.json
./protobuf.js-protobufjs-v7.2.5/cli/bin/pbjs  -t json msg.proto > msg.json

• 命令行参数如下：

  -t, --target     Specifies the target format. Also accepts a path to require a custom target.json          JSON representationjson-module   JSON representation as a moduleproto2        Protocol Buffers, Version 2proto3        Protocol Buffers, Version 3static        Static code without reflection (non-functional on its own)static-module Static code without reflection as a module-p, --path       Adds a directory to the include path.-o, --out        Saves to a file instead of writing to stdout.--sparse         Exports only those types referenced from a main file (experimental).Module targets only:-w, --wrap       Specifies the wrapper to use. Also accepts a path to require a custom wrapper.default   Default wrapper supporting both CommonJS and AMDcommonjs  CommonJS wrapperamd       AMD wrapperes6       ES6 wrapper (implies --es6)closure   A closure adding to protobuf.roots where protobuf is a global-r, --root       Specifies an alternative protobuf.roots name.-l, --lint       Linter configuration. Defaults to protobuf.js-compatible rules:eslint-disable block-scoped-var, no-redeclare, no-control-regex, no-prototype-builtins--es6            Enables ES6 syntax (const/let instead of var)Proto sources only:--keep-case      Keeps field casing instead of converting to camel case.Static targets only:--no-create      Does not generate create functions used for reflection compatibility.--no-encode      Does not generate encode functions.--no-decode      Does not generate decode functions.--no-verify      Does not generate verify functions.--no-convert     Does not generate convert functions like from/toObject--no-delimited   Does not generate delimited encode/decode functions.--no-beautify    Does not beautify generated code.--no-comments    Does not output any JSDoc comments.--force-long     Enfores the use of 'Long' for s-/u-/int64 and s-/fixed64 fields.--force-message  Enfores the use of message instances instead of plain objects.usage: pbjs [options] file1.proto file2.json ...  (or pipe)  other | pbjs [options] -

3、node 代码示例

3.1 HTTP

一旦你已经安装了 Node，让我们尝试构建第一个 Web 服务器。然后使用 node server.js 运行程序，访问 http://localhost:3000，你就会看到一个消息，写着“Hello World”。

• server.js

const http = require('http');
const hostname = '127.0.0.1';
const port = 3000;const server = http.createServer((req, res) => {res.statusCode = 200;res.setHeader('Content-Type', 'text/plain;charset=utf-8');res.end('Hello World, 爱看书的小沐！2023！\n');
});server.listen(port, hostname, () => {console.log(`服务器运行在 http://${hostname}:${port}/`);
});

运行脚本：

node server.js

浏览器访问http服务器：

http://127.0.0.1:3000/

var http = require('http');
var hostname = '127.0.0.1';
var port = 3000;http.createServer(function(req, res) {res.writeHead(200, {'Content-Type': 'text/html'});res.write('<head><meta charset="utf-8"/></head>');res.write('<h1>Node.js</h1>');res.write('<b>爱看书的小沐！2023！</b>');res.end('<p>Hello World</p>');}).listen(port);console.log("HTTP server is listening at port ${port}.");
console.log(`服务器运行在 http://${hostname}:${port}/`);

3.2 UDP单播

UDP单播例子一

• 制作一个文件 (“demo_dgram.js”) 监听 8080 端口上的消息：

var dgram = require('dgram');
var s = dgram.createSocket('udp4');
s.on('message', function(msg, rinfo) {console.log('I got this message: ' + msg.toString());
});
s.bind(8080);

• 制作一个向 8080 端口发送消息的文件(“demo_dgram_send.js”) :

var dgram = require('dgram');
var s = dgram.createSocket('udp4');
s.send(Buffer.from('abc'), 8080, 'localhost');

UDP单播例子二

• 服务器：udp_server.js

// 例子：UDP服务端
var PORT = 9090;
var HOST = '127.0.0.1';var dgram = require('dgram');
var server = dgram.createSocket('udp4');server.on('listening', function () {var address = server.address();console.log('UDP Server listening on ' + address.address + ":" + address.port);
});server.on('message', function (message, remote) {console.log(remote.address + ':' + remote.port +' - ' + message);
});server.bind(PORT, HOST);

• 客户端：udp_client.js

// 例子：UDP客户端
var PORT = 9090;
var HOST = '127.0.0.1';var dgram = require('dgram');
var message = Buffer.from('This is 爱看书的小沐!');var client = dgram.createSocket('udp4');client.send(message, PORT, HOST, function(err, bytes) {if (err) throw err;console.log('UDP message sent to ' + HOST +':'+ PORT);client.close();
});

3.4 UDP广播

• 服务器：boardcast_server.js

var dgram = require('dgram');
var server = dgram.createSocket('udp4');
var port = 8080;server.on('message', function(message, rinfo){console.log('server got message from: ' + rinfo.address + ':' + rinfo.port);
});server.on('listening', function () {var address = server.address();console.log('Boardcast Server listening on ' + address.address + ":" + address.port);
});server.bind(port);

• 客户端：boardcast_client.js

var dgram = require('dgram');
var client = dgram.createSocket('udp4');
var msg = Buffer.from('hello world, 爱看书的小沐！');
var port = 8080;
var host = '255.255.255.255';client.bind(function(){client.setBroadcast(true);// client.send(msg, port, host, function(err){//     if(err) throw err;//     console.log('msg has been sent');//     client.close();// });// 循环发送消息setInterval(function(){client.send(msg, port, host, function(err){if(err) throw err;console.log('msg has been sent');});}, 1000);});

4、Protobuf 代码示例

4.1 例子: awesome.proto

• awesome.proto的内容定义如下：

// awesome.proto
package awesomepackage;
syntax = "proto3";message AwesomeMessage {string awesome_field = 1; // becomes awesomeFieldstring name_field = 2;
}

4.1.1 加载.proto文件方式

• 测试脚本文件：app_proto001.js

var protobuf = require("protobufjs");protobuf.load("awesome.proto", function(err, root) {if (err)throw err;var AwesomeMessage = root.lookupType("awesomepackage.AwesomeMessage");var payload = { awesomeField: "AwesomeString" };var message = AwesomeMessage.create(payload); var buffer = AwesomeMessage.encode(message).finish();
});

var protobuf = require("protobufjs");protobuf.load("awesome.proto", function(err, root) {if (err)throw err;// Obtain a message typevar AwesomeMessage = root.lookupType("awesomepackage.AwesomeMessage");// Exemplary payloadvar payload = { awesomeField: "AwesomeString" };console.log("payload: " + JSON.stringify(payload));// Verify the payload if necessary (i.e. when possibly incomplete or invalid)var errMsg = AwesomeMessage.verify(payload);if (errMsg)throw Error(errMsg);// Create a new messagevar message = AwesomeMessage.create(payload); // or use .fromObject if conversion is necessaryconsole.log("create: " + JSON.stringify(message));// Encode a message to an Uint8Array (browser) or Buffer (node)var buffer = AwesomeMessage.encode(message).finish();// ... do something with bufferconsole.log("encode: " + JSON.stringify(buffer));// Decode an Uint8Array (browser) or Buffer (node) to a messagevar message = AwesomeMessage.decode(buffer);// ... do something with messageconsole.log("decode: " + JSON.stringify(message));// If the application uses length-delimited buffers, there is also encodeDelimited and decodeDelimited.// Maybe convert the message back to a plain objectvar object = AwesomeMessage.toObject(message, {longs: String,enums: String,bytes: String,// see ConversionOptions});console.log("toObject: " + JSON.stringify(object));
});

执行运行命令如下：

node app_proto001.js

4.1.2 加载.json文件方式

执行如下命令，将awesome.proto转为awesome.json:

./node_modules/protobufjs/bin/pbjs -t json awesome.proto > awesome.json

自动生成的awesome.json如下：

{"nested": {"awesomepackage": {"nested": {"AwesomeMessage": {"fields": {"awesomeField": {"type": "string","id": 1},"nameField": {"type": "string","id": 2}}}}}}
}

编写脚本代码如下：

var protobuf = require("protobufjs");var jsonDescriptor = require("./awesome.json"); // exemplary for nodevar root = protobuf.Root.fromJSON(jsonDescriptor);// Obtain a message type
var AwesomeMessage = root.lookupType("awesomepackage.AwesomeMessage");// Exemplary payload
var payload = { awesomeField: "AwesomeString", nameField: "AwesomeName"};
console.log("payload: " + JSON.stringify(payload));// Verify the payload if necessary (i.e. when possibly incomplete or invalid)
var errMsg = AwesomeMessage.verify(payload);
if (errMsg)throw Error(errMsg);// Create a new message
var message = AwesomeMessage.create(payload); // or use .fromObject if conversion is necessary
console.log("create: " + JSON.stringify(message));// Encode a message to an Uint8Array (browser) or Buffer (node)
var buffer = AwesomeMessage.encode(message).finish();
// ... do something with buffer
console.log("encode: " + JSON.stringify(buffer));// Decode an Uint8Array (browser) or Buffer (node) to a message
var message = AwesomeMessage.decode(buffer);
// ... do something with message
console.log("decode: " + JSON.stringify(message));// If the application uses length-delimited buffers, there is also encodeDelimited and decodeDelimited.// Maybe convert the message back to a plain object
var object = AwesomeMessage.toObject(message, {longs: String,enums: String,bytes: String,// see ConversionOptions
});
console.log("toObject: " + JSON.stringify(object));

运行结果如下：

4.1.3 加载.js文件方式

通过如下命令转为.proto为对应的.js文件

C:\Users\tomcat\Desktop\test>C:\Users\tomcat\Desktop\protobuf.js-protobufjs-v7.2.5\node_modules\.bin\pbjs  -t static-module -w commonjs -o awesome.js awesome.proto

生成的awesome.js 部分内容如下：

编写测试脚本代码如下：

var protobuf = require("protobufjs");var awesomeProto = require("./awesome.js"); // exemplary for node
var AwesomeUtils = awesomeProto.awesomepackage.AwesomeMessage;// Exemplary payload
var payload = { awesomeField: "AwesomeString", nameField: "AwesomeName"};
console.log("payload: " + JSON.stringify(payload));// Verify the payload if necessary (i.e. when possibly incomplete or invalid)
var errMsg = AwesomeUtils.verify(payload);
if (errMsg)throw Error(errMsg);// Create a new message
var message = AwesomeUtils.create(payload); // or use .fromObject if conversion is necessary
console.log("create: " + JSON.stringify(message));// Encode a message to an Uint8Array (browser) or Buffer (node)
var buffer = AwesomeUtils.encode(message).finish();
// ... do something with buffer
console.log("encode: " + JSON.stringify(buffer));// Decode an Uint8Array (browser) or Buffer (node) to a message
var message = AwesomeUtils.decode(buffer);
// ... do something with message
console.log("decode: " + JSON.stringify(message));// If the application uses length-delimited buffers, there is also encodeDelimited and decodeDelimited.// Maybe convert the message back to a plain object
var object = AwesomeUtils.toObject(message, {longs: String,enums: String,bytes: String,// see ConversionOptions
});
console.log("toObject: " + JSON.stringify(object));

运行脚本文件如下：

node app_awesome.js

4.2 例子：account.proto

• account.proto

// account.proto
package yxy;
syntax = "proto3";message Account{required string name = 1; //帐号名required string pwd = 2; //帐号密码
}message AccountList{required int32 index = 1;repeated Account list = 2;
}

4.2.1 create(…)创建对象

• app_account.js

var ProtoBufJs = require("protobufjs");
var root = ProtoBufJs.loadSync("./account.proto");
var AccountList = root.lookupType("yxy.AccountList");
var Account = root.lookupType("yxy.Account");
var accountListObj = AccountList.create();for(var i = 0; i < 10; i++){var accountObj = Account.create();accountObj.name = "杨小羊_"+i;accountObj.pwd = "pwd_"+i;accountListObj.list.push(accountObj);
}var buffer = AccountList.encode(accountListObj).finish();console.log("data: " + JSON.stringify(accountListObj));
console.log("encode: " + JSON.stringify(buffer));

执行命令如下：

node app_account.js

4.2.2 fromObject(…)创建对象

var ProtoBufJs = require("protobufjs");
var root = ProtoBufJs.loadSync("./account.proto");
var AccountList = root.lookupType("yxy.AccountList");
var Account = root.lookupType("yxy.Account");var accountObj1 = Account.fromObject({pwd:"666", name:"杨小羊"});
var accountObj2 = Account.fromObject({pwd:"777", name:"杨大羊"});
var accountObj3 = Account.fromObject({pwd:"888", name:"杨胖羊"});
var accountListObj = AccountList.fromObject({index:"0", list:[accountObj1,accountObj2,accountObj3]});
var buffer = AccountList.encode(accountListObj).finish();console.log("data: " + JSON.stringify(accountListObj));
console.log("encode: " + JSON.stringify(buffer));

执行结果如下：

4.3 例子：hello.proto + udp

• hello.proto

package yxy;
message helloworld
{message helloReq { required string name = 1; }message helloRsp{required int32 retcode = 1;optional string reply = 2;}
}

4.3.1 服务端：yxy_server.js

• yxy_server.js

var ProtoBuf = require("protobufjs");
var dgram = require('dgram');
var PORT = 8080;
var HOST = '127.0.0.1';var server = dgram.createSocket('udp4');
var root = ProtoBuf.loadSync("./hello.proto");
var HelloReq = root.lookupType("yxy.helloworld.helloReq");
var HelloRsp = root.lookupType("yxy.helloworld.helloRsp");server.on('listening', function () {var address = server.address();console.log('UDP Server listening on ' + address.address + ":" + address.port);
});server.on('message', function (message, remote) {console.log(remote.address + ':' + remote.port + ' - ' + message);console.log(HelloReq.decode(message) + ' from client!');var hCReq = HelloRsp.fromObject({retcode:200, reply:'Yeah!I\'m 杨小羊!'});var message = HelloRsp.encode(hCReq).finish();server.send(message, 0, message.length, remote.port, remote.address, function (err, bytes) {if (err) {throw err;}console.log('UDP message reply to ' + remote.address + ':' + remote.port);})
});server.bind(PORT, HOST);

4.3.2 客户端：yxy_client.js

var dgram = require('dgram');
var ProtoBuf = require("protobufjs");
var PORT = 8080;
var HOST = '127.0.0.1';var root = ProtoBuf.loadSync("./hello.proto");
var HelloReq = root.lookupType("yxy.helloworld.helloReq");
var HelloRsp = root.lookupType("yxy.helloworld.helloRsp");var hCReq = HelloReq.fromObject({name:"杨小羊"});
var buffer = HelloReq.encode(hCReq).finish();
message = buffer; var socket = dgram.createSocket({type: 'udp4',fd: PORT
}, function (err, message) {if (err) {console.log(err);}console.log(message);
});socket.send(message, 0, message.length, PORT, HOST, function (err, bytes) {if (err) {throw err;}console.log('UDP message sent to ' + HOST + ':' + PORT);
});socket.on("message", function (msg, rinfo) {console.log("[Client] Received message: " + HelloRsp.decode(msg).reply + " from " + rinfo.address + ":" + rinfo.port);console.log(HelloRsp.decode(msg));socket.close();
});socket.on('close', function () {console.log('socket closed.');
});socket.on('error', function (err) {socket.close();console.log('socket err');console.log(err);
});

4.4 例子：user.proto + tcp

• user.proto

syntax = "proto3";
package yxy;message Login {required string name = 1;required string pwd = 2;
}
message Address{string province = 1;string city = 2;string country = 3;
}

4.4.1 服务端：yxy_tcpserver.js

• yxy_tcpserver.js

const net = require("net");
const protobuf = require("protobufjs");
const PORT = 9090;
const HOST = '127.0.0.1';protobuf.load("./user.proto", (err, root) => {if (err) throw err;const LoginMessage = root.lookupType("yxy.Login");const server = net.createServer((socket) => {console.log("New client connected");socket.on("data", (data) => {// 解码数据 const message = LoginMessage.decode(data);// 在这里处理消息console.log(message);// 编码响应 const responseData = LoginMessage.encode({name: "杨小羊",pwd: "123456"}).finish();// 将响应写回到连接 socket.write(responseData);});socket.on("close", () => {console.log("Client disconnected");});});server.listen(PORT, () => {console.log(`Server listening on localhost:${PORT}`);});
});

4.4.2 客户端：yxy_tcpclient.js

• yxy_tcpclient.js

const net = require("net");
const protobuf = require("protobufjs");
const PORT = 9090;
const HOST = '127.0.0.1';protobuf.load("./user.proto", (err, root) => {if (err) throw err;const LoginMessage = root.lookupType("yxy.Login");const client = net.createConnection({port: PORT}, () => {console.log("Connected to server");// 编码数据 const data = LoginMessage.encode({name: "爱看书的小沐",pwd: "666666"}).finish();// 将数据写到连接 client.write(data);});client.on("data", (data) => {// 解码服务器的响应 const message = LoginMessage.decode(data);// 在这里处理响应 console.log(message);});client.on("close", () => {console.log("Connection closed");});
});

结语

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