pomelo源代码分析(一)

千里之行始于足下，一直说想了解pomelo，对pomelo有兴趣，但一直迟迟没有去碰，尽管对pomelo进行源代码分析，在网络上肯定不止我一个，已经有非常优秀的前辈走在前面，如http://golanger.cn/，在阅读Pomelo代码的时候，已经连载到了11篇了，在我的源代码分析參考了该博客，当然，也会添�我对pomelo的理解，借此希望能提高一下自己对node.js的了解和学习一些优秀的设计。

• 开发环境：win7
• 调试环境：webstorm5.0
• node.js版本号：v0.8.21
• 源代码版本号package.json：

{
	"name": "chatofpomelo",
	"version": "0.0.1",
	"private": false,
	"dependencies": {
		"pomelo": "0.2.0",
		"log4js": ">= 0.4.1",
		"crc": ">=0.0.1"
	}
}

gameserver/app.js

var pomelo = require('pomelo');
var routeUtil = require('./app/util/routeUtil');
/**
 * Init app for client.
 */
var app = pomelo.createApp();     //创建Application
app.set('name', 'chatofpomelo');  //设置Application名字

// app configure
app.configure('production|development', function() {
	// route configures
	app.route('chat', routeUtil.chat);

	// filter configures
	app.filter(pomelo.timeout());
});

// start app
app.start();

process.on('uncaughtException', function(err) {
	console.error(' Caught exception: ' + err.stack);
});

注意：在webstorm下调试，可能由于工作文件夹的设置原因会导致应用的运行路径问题，导致无法读取配置文件，所以须要依据实际情况改动例如以下

var opt = {'base':'D:\\src\\pomelo\\chatofpomelo\\game-server'}
var app = pomelo.createApp(opt);
app.set('name', 'chatofpomelo');

opt.base 是你的game-server的实际文件夹路径，详细能够依据自己须要来定制

app.js 是game-server的主要入口，主要负责创建application，读取配置文件，应用到application设置上，并利用app.start()来运行实际的master，monitor等服务器的start，对于聊天室程序来说，还要做简单的路由和过滤设置。

application, 应用的定义、component管理，上下文配置， 这些使pomelo framework的对外接口非常easy， 而且具有松耦合、可插拔架构。

全部server的启动都是从执行app.js開始。每个server的启动都首先创建一个全局唯一的application对象，该对象中挂载了所在server的全部信息，包含server物理信息、server逻辑信息、以及pomelo的组件信息等。同一时候，该对象还提供应用管理和配置等基本方法。 在app.js中调用app.start()方法后，application对象首先会通过loadDefaultComponents方法载入默认的组件。

pomelo/lib/pomelo.js

var application = require('./application');

Pomelo.createApp = function (opts) {
  var app = application;
  app.init(opts);
  self.app = app;
  return app;
};

pomelo/lib/application.js

/**
 * Application prototype.
 *
 * @module
 */
var Application = module.exports = {};

/**
 * Application states
 */
var STATE_INITED  = 1;  // app has inited
var STATE_START = 2;  // app start
var STATE_STARTED = 3;  // app has started
var STATE_STOPED  = 4;  // app has stoped

/**
 * Initialize the server.
 *
 *   - setup default configuration
 *
 * @api private
 */
Application.init = function(opts) {
  opts = opts || {};
  logger.info('app.init invoked');
  this.loaded = [];
  this.components = {};
  this.settings = {};   // set，和get功能的容器
  this.set('base', opts.base);  //设置服务器的工作文件夹
  this.defaultConfiguration();  //依据配置文件，载入master，monitor等服务器
  this.state = STATE_INITED;  //application工作状态
  logger.info('application inited: %j', this.get('serverId'));
};

pomelo/lib/application.js

/**
 * Initialize application configuration.
 *
 * @api private
 */
Application.defaultConfiguration = function () {
  var args = utils.argsInfo(process.argv);
  this.setupEnv(args); //application环境设置
  this.loadServers();  //载入server配置信息
  this.loadConfig('master', this.getBase() + '/config/master.json'); //载入materserver配置信息
  this.processArgs(args); //依据启动參数设定server配置
  this.configLogger();
};

utils.argsInfo(process.argv); 获取系统启动參数，我们最好还是看看究竟有哪些參数支持

启动game-server服务器：>pomelo start [development | production] [--daemon]

依据args參数设定application的工作环境是development或production

/**
 * Setup enviroment.
 * @api private
 */
Application.setupEnv = function(args) {
  this.set('env', args.env || process.env.NODE_ENV || 'development', true);
};

载入服务器信息，而且保存在__serverMap___内存下

/**
 * Load server info from configure file.
 *
 * @api private
 */
Application.loadServers = function() {
  this.loadConfig('servers', this.getBase() + '/config/servers.json');
  var servers = this.get('servers');
  var serverMap = {}, slist, i, l, server;
  for(var serverType in servers) {
    slist = servers[serverType];
    for(i=0, l=slist.length; i<l; i++) {
      server = slist[i];
      server.serverType = serverType;
      serverMap[server.id] = server;
    }
  }

  this.set('__serverMap__', serverMap);
};

server.json

{
    "development":{
        "connector":[
             {"id":"connector-server-1", "host":"127.0.0.1", "port":4050, "wsPort":3050},
             {"id":"connector-server-2", "host":"127.0.0.1", "port":4051, "wsPort":3051},
             {"id":"connector-server-3", "host":"127.0.0.1", "port":4052, "wsPort":3052}
         ],
        "chat":[
             {"id":"chat-server-1", "host":"127.0.0.1", "port":6050},
             {"id":"chat-server-2", "host":"127.0.0.1", "port":6051},
             {"id":"chat-server-3", "host":"127.0.0.1", "port":6052}
        ],
        "gate":[
	     {"id": "gate-server-1", "host": "127.0.0.1", "wsPort": 3014}
	]
    },
    "production":{
       "connector":[
             {"id":"connector-server-1", "host":"127.0.0.1", "port":4050, "wsPort":3050},
             {"id":"connector-server-2", "host":"127.0.0.1", "port":4051, "wsPort":3051},
             {"id":"connector-server-3", "host":"127.0.0.1", "port":4052, "wsPort":3052}
         ],
        "chat":[
             {"id":"chat-server-1", "host":"127.0.0.1", "port":6050},
             {"id":"chat-server-2", "host":"127.0.0.1", "port":6051},
             {"id":"chat-server-3", "host":"127.0.0.1", "port":6052}
        ],
        "gate":[
	     {"id": "gate-server-1", "host": "127.0.0.1", "wsPort": 3014}
	]
  }
}

工具函数，读取json配置文件，在这里读取的是master.json文件

/**
 * Load Configure json file to settings.
 *
 * @param {String} key environment key
 * @param {String} val environment value
 * @return {Server|Mixed} for chaining, or the setting value
 *
 * @memberOf Application
 */
Application.loadConfig = function (key, val) {
  var env = this.get('env');
  val = require(val);
  if (val[env]) {
    val = val[env];
  }
  this.set(key, val);
};

master.json

{
    "development":{
        "id":"master-server-1",
        "host":"127.0.0.1",
        "port":3005,
        "queryPort":3015,
        "wsPort":2337
    },

    "production":{
        "id":"master-server-1",
        "host":"127.0.0.1",
        "port":3005,
        "queryPort":3015,
        "wsPort":2337
    }

}

依据进程读取配置好的參数，配置server。

Application.processArgs = function(args){
  var serverType = args.serverType || 'master';
  var serverId = args.serverId || this.get('master').id;
  this.set('main', args.main, true);
  this.set('serverType', serverType, true);
  this.set('serverId', serverId, true);
  if(serverType !== 'master') {
    this.set('curServer', this.getServerById(serverId), true);
  } else {
    this.set('curServer', this.get('master'), true);
  }
};

项目的日志配置

Application.configLogger = function() {
  if(process.env.POMELO_LOGGER !== 'off') {
    log.configure(this, this.getBase() + '/config/log4js.json');
  }
};

log4js.json

{
  "appenders": [
    {
      "type": "file",
      "filename": "./logs/node-log-${opts:serverId}.log",
      "fileSize": 1048576,
      "layout": {
        "type": "basic"
      },
      "backups": 5
    },
    {
      "type": "console"
    },
    {
      "type": "file",
      "filename": "./logs/con-log-${opts:serverId}.log",
      "pattern": "connector",
      "fileSize": 1048576,
      "layout": {
          "type": "basic"
        }
      ,"backups": 5,
      "category":"con-log"
    },
    {
      "type": "file",
      "filename": "./logs/rpc-log-${opts:serverId}.log",
      "fileSize": 1048576,
      "layout": {
          "type": "basic"
        }
      ,"backups": 5,
      "category":"rpc-log"
    },
    {
      "type": "file",
      "filename": "./logs/forward-log-${opts:serverId}.log",
      "fileSize": 1048576,
      "layout": {
          "type": "basic"
        }
      ,"backups": 5,
      "category":"forward-log"
    },
    {
      "type": "file",
      "filename": "./logs/crash.log",
      "fileSize": 1048576,
      "layout": {
          "type": "basic"
        }
      ,"backups": 5,
      "category":"crash-log"
    }
  ],

  "levels": {
  	"rpc-log" : "ERROR",
    "forward-log": "ERROR"
  }, 

  "replaceConsole": true
}