restartable/lib/restartable.js

a simple way to restart your app without actually restarting node.js

var cluster = require("cluster");

var MessageAdapter = require("message-adapter");

var _restartable = function(parClusterCode, parMainCode){
  this.isRestartable = !cluster.isMaster;
  if (!this.isRestartable){
    this._fork.apply(this);
    if (parMainCode){
      parMainCode(this);
    };
  };
  if (this.isRestartable){
    this._initWorker(parClusterCode);
  };
  
};

_restartable.prototype._initWorker = function(parFun){
  this._messageAdapter = new MessageAdapter();
  this._messageAdapter.on("_data", function(parJsn){
    process.send(parJsn);
  });
  var self = this;
  process.on("message", function(parJsn){
    self._messageAdapter.jsonData(parJsn);
  });
  
  if (parFun){
    parFun(this);
  };
};


_restartable.prototype.restart = function(){
  if (this.isRestartable){
    cluster.worker.kill();
  }else{
    this.clusterInstance.kill();
  };
};

_restartable.prototype._fork = function(){
  var self = this;
  if (this._messageAdapter){
    //this._messageAdapter.destroy();
  };
  this._messageAdapter = new MessageAdapter();
  
  this.clusterInstance = cluster.fork();
  this.clusterInstance.on("exit", function(){
    self._fork();
  });
  this.clusterInstance.on("message", function(parJsn){
    //console.log(self._messageAdapter);
    self._messageAdapter.jsonData(parJsn);
  });
  this._messageAdapter.on("_data", function(parJsn){
    self.clusterInstance.send(parJsn);
  });
};

// simply forward the emit / on functions to the adapter
_restartable.prototype.emit = function(){
  return this._messageAdapter.emit.apply(this._messageAdapter, arguments);
};
_restartable.prototype.on = function(){
  return this._messageAdapter.on.apply(this._messageAdapter, arguments);
};
_restartable.prototype.getSub = function(){
  return this._messageAdapter.getSub.apply(this._messageAdapter, arguments);
};


var restartable = function(parClusterCode, parMainCode){
  return new _restartable(parClusterCode, parMainCode);
};

module.exports = restartable;