iopa-udp/src/server/udp.js

API-First User Datagram Protocol (UDP) stack for Internet of Things (IoT), based on Internet of Protocols Alliance (IOPA) specification

/*
 * Copyright (c) 2015 Internet of Protocols Alliance (IOPA)
 *
 * Licensed under the Apache License, Version 2.0 (the "License");
 * you may not use this file except in compliance with the License.
 * You may obtain a copy of the License at
 *
 *      http://www.apache.org/licenses/LICENSE-2.0
 *
 * Unless required by applicable law or agreed to in writing, software
 * distributed under the License is distributed on an "AS IS" BASIS,
 * WITHOUT WARRANTIES OR CONDITIONS OF ANY KIND, either express or implied.
 * See the License for the specific language governing permissions and
 * limitations under the License.
 */

// DEPENDENCIES
var iopa = require('iopa');
var UdpComplex = require('./udpComplex.js');

const IOPA = iopa.constants.IOPA,
      SERVER = iopa.constants.SERVER
	  
const packageVersion = require('../../package.json').version;

function _classCallCheck(instance, Constructor) { if (!(instance instanceof Constructor)) { throw new TypeError("Cannot call a class as a function"); } }

/* *********************************************************
 * IOPA UDP MIDDLEWARE
 * ********************************************************* */

/**
 * Representes UDP Server
 *
 * @class UdpServer
 * @param app The IOPA AppBuilder dictionary
 * @constructor
 * @public
 */
function IopaUdp(app) {
  _classCallCheck(this, IopaUdp);

   app.properties[SERVER.Capabilities][IOPA.CAPABILITIES.Udp] = {};
   app.properties[SERVER.Capabilities][IOPA.CAPABILITIES.Udp][SERVER.Version] = packageVersion;
   app.properties[SERVER.Capabilities][IOPA.CAPABILITIES.Udp][SERVER.LocalPort] =[];

   app.createServer = this._appCreateServer.bind(this, app.createServer || function(){ throw new Error("no registered transport provider"); });
   app.getServer = this._appGetServer.bind(this, app.getServer || function(){ return null; });
  
   this.app = app; 
   this._servers = [];
 }

IopaUdp.prototype._appCreateServer = function(next, transport, options){
  if (transport !== "udp:")
    return next(transport, options);
    
   options = options || {};
  
  if (!this.app.properties[SERVER.IsBuilt]) 
    this.app.build();   
   
  var server = new UdpComplex(options, this.app.properties[SERVER.Pipeline]);
  var that = this;
  server.once("close", function(){that._servers.splice(that._servers.indexOf(server),1); server = null; });
  this._servers.push(server);
  return server;
}

IopaUdp.prototype._appGetServer = function(next, transport, query){
  if (transport !== "udp:")
    return next(transport, query);
    
   query = query || {};
  
   if (!query)
     return this._servers[0];
  
   if (typeof query == 'number')
     return this._appGetServerByPort(query);
     
    if (typeof query == 'string')
     return this._appGetServerById(query);
   
  return null;
}

IopaUdp.prototype._appGetServerByPort = function (port) {
  var _server = null;
  this._servers.some(function (server) {
    if ((server[SERVER.LocalPort] == port)
      || (server.multicastserver && server.multicastserver[SERVER.LocalPort] == port)) {
      _server = server;
      return true;
    }
  });

  return _server;
}


IopaUdp.prototype._appGetServerById = function (id) {
  var _server = null;
  this._servers.some(function (server) {
    if (server[SERVER.Id] == id) {
      _server = server;
      return true;
    }
  });

  return _server;
}

module.exports = IopaUdp;