【小沐学前端】Node.js实现基于Protobuf协议的数据处理

标签：Node stringify console Protobuf js var message AwesomeMessage payload

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。

2、Protobuf 代码示例

2.1 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 awesomeField
    string name_field = 2;
}

2.1.1 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 type
    var AwesomeMessage = root.lookupType("awesomepackage.AwesomeMessage");

    // Exemplary payload
    var 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 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));
});

执行运行命令如下：

node app_proto001.js

在这里插入图片描述

2.1.2 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 node

var 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：在这里插入图片描述

2.1.3 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：在这里插入图片描述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

在这里插入图片描述

2.2 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;
}

2.2.1 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

在这里插入图片描述

2.2.2 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：在这里插入图片描述

结语

如果您觉得该方法或代码有一点点用处，可以给作者点个赞，或打赏杯咖啡；╮(￣▽￣)╭ 如果您感觉方法或代码不咋地//(ㄒoㄒ)//，就在评论处留言，作者继续改进；o_O??? 如果您需要相关功能的代码定制化开发，可以留言私信作者；(✿◡‿◡) 感谢各位大佬童鞋们的支持！( ´ ▽´ )ﾉ ( ´ ▽´)っ！！！

标签：Node,stringify,console,Protobuf,js,var,message,AwesomeMessage,payload
From： https://blog.51cto.com/fish/8664920

【小沐学前端】Node.js实现基于Protobuf协议的数据处理

1、简介

1.1 node

2、Protobuf 代码示例

2.1 例子: awesome.proto

2.1.1 加载.proto文件方式

2.1.2 加载.json文件方式

2.1.3 加载.js文件方式

2.2 例子：account.proto

2.2.1 create(...)创建对象

2.2.2 fromObject(...)创建对象

结语

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