drachtio-modesl/lib/esl/Server.js

FreeSWITCH ESL Node.js Implementation

var EventEmitter2 = require('eventemitter2').EventEmitter2,
    util = require('util'),
    net = require('net'),
    crypto = require('crypto'),
    Connection = require('./Connection');

var Server = module.exports = function(opts, readyCb) {
    EventEmitter2.call(this, {
        wildcard: true,
        delimiter: '::',
        ignoreErrors: true,
        maxListeners: 25
    });

    if(typeof opts === 'function') {
        readyCb = opts;
        opts = null;
    }

    readyCb = readyCb || function() {};

    this.connections = {};

    //OR 0 will floor the value
    this.seq = Date.now() | 0;

    this.once('ready', readyCb);

    opts = opts || {};

    this.bindEvents = opts.myevents || false;

    if(opts.server) {
        this.port = opts.server.address().port;
        this.host = opts.server.address().host;

        this.server = opts.server;

        //make sure we dont call the callback before the function returns
        var self = this;
        process.nextTick(function() {
            self.emit('ready');
        });

        this.server.on('connection', this._onConnection.bind(this));
    }
    else {
        this.port = opts.port || 8022;
        this.host = opts.host || '127.0.0.1';

        this.server = net.createServer(this._onConnection.bind(this));
        this.server.listen(this.port, this.host, this._onListening.bind(this));
    }
};

util.inherits(Server, EventEmitter2);

Server.prototype.close = function(callback) {
	this.server.close(callback);
};

Server.prototype._onConnection = function(socket) {
    var conn = new Connection(socket),
    id = this._generateId();

    this.connections[id] = conn;
    this.connections[id]._id = id;

    this.emit('connection::open', conn, id);

    conn.on('esl::ready', function(id) {
        if(this.bindEvents) {
            conn.sendRecv('myevents', function() {
                this.emit('connection::ready', this.connections[id], id);
            }.bind(this));
        }else{
            this.emit('connection::ready', this.connections[id], id);
        }
    }.bind(this, id));

    conn.on('esl::end', function(id) {
        this.emit('connection::close', this.connections[id], id);

        delete this.connections[id];
    }.bind(this, id));
};

Server.prototype._onListening = function() {
    this.emit('ready');
};

Server.prototype._generateId = function() {
    var rand = new Buffer(15); // multiple of 3 for base64

    //next in sequence
    this.seq = (this.seq + 1) | 0;

    //write sequence to last 4 bytes of buffer
    rand.writeInt32BE(this.seq, 11);

    //write random to first 11 bytes of buffer
    crypto.randomBytes(11).copy(rand);

    //make the base64 safe for an object property
    return rand.toString('base64').replace(/\//g, '_').replace(/\+/g, '-');
};

Server.prototype.getCountOfConnections = function() {
    return Object.keys(this.connections).length;
};