How to use the mongodb.Connection function in mongodb

/* 
 This file contains proprietary software owned by Motorola Mobility, Inc.<br>
 No rights, expressed or implied, whatsoever to this software are provided by Motorola Mobility, Inc. hereunder.<br>
 (c) Copyright 2011 Motorola Mobility, Inc.  All Rights Reserved.
  */
var Db = require('mongodb').Db;
var BSON = require('mongodb').BSONPure
var Connection = require('mongodb').Connection;
var Server = require('mongodb').Server;

module.exports = MongoDbProvider;

function MongoDbProvider(host, port) {
    this._db = new Db("screening", new Server(host, port, {auto_reconnect: true}, {}));
    this._db.open(function(err, dbConn) {
        if (err) {
            console.error("Couldn't connect to MongoDB, plese check /docs/MongoDb.md for info on how to setup the MongoDB server", err.message);
            process.exit(1);
        } else {
            console.log("Connected to MongoDB server on " + dbConn.serverConfig.host + ":" + dbConn.serverConfig.port + ", database: " + dbConn.databaseName);
        }
    });

    return this;

var Storage = function(options) {
    // set options and load defaults if needed
    this.options = options || {};
    this.options.host = this.options.host || 'localhost';
    this.options.port = this.options.port || mongo.Connection.DEFAULT_PORT;
        
    this.collectionName = 'events';
    this.store = new mongo.Db('eventstore'
                             , new mongo.Server(this.options.host, this.options.port, {}), {});
                             
    this.store.addListener("error", function(error) {
        console.log("Error connecting to mongo -- perhaps it isn't running?");
    });
    
    this.client = undefined;
    
    this.store.open(function(err, client) {
        this.client = client;
    }.bind(this));
    
};

function onOpened(err, db) {
    // TODO: report errors somewhere?
    if (err) { return ; }
    _db = db;
    arbiter.emit("db_open", db);
  }

  if (db_url) {
    var options = {
      uri_decode_auth: true,
      server: server_options,
      db: db_options
    };
    mongo.connect(db_url, options, onOpened);
  } else {
    var port = mongo.Connection.DEFAULT_PORT;
    var mongoserver = new mongo.Server(host, port, server_options);
    var db_connector = new mongo.Db(db_name, mongoserver, db_options);
    _db = db_connector;
  }

  return {
    /**
     * This function returns a collection from the mongo DB, making sure that
     * the DB is created before using it.
     *
     * @method get
     * @param {String} db_name* A namespaced name for the DB
     * @param {Function} cb Function to run when the DB is returned.
     */
    get: function() {
      var cb;

var app = express(),
    http = require('http'),
    server = http.createServer(app);
var WebSocketServer = require('websocket').server;
//  io = require('socket.io').listen(server);
//var WebSocketServer = require('ws').Server;

var csv = require('csv');
var sys = require('sys');
var fs = require('fs');
var path = require('path');
var config = require('./config.json');
var mongo = require('mongodb');
var BSON = mongo.BSONPure;
var Db = mongo.Db,
    Connection = require('mongodb').Connection,
    Server = require('mongodb').Server;
var passport = require('passport'),
    TwitterStrategy = require('passport-twitter').Strategy;
var logger = require('morgan');
var cookieParser = require('cookie-parser');
var bodyParser = require('body-parser');
var session = require('express-session');

var multer = require('multer');
var upload = multer({
    dest: config.uploadDirectory
});


var host = process.env['MONGO_NODE_DRIVER_HOST'] != null ? process.env['MONGO_NODE_DRIVER_HOST'] : 'localhost';
var port = process.env['MONGO_NODE_DRIVER_PORT'] != null ? process.env['MONGO_NODE_DRIVER_PORT'] : Connection.DEFAULT_PORT;

var rservs = []
      for( var i = 0; i < conf.replicaset.servers.length; i++ ) {
	var servconf = conf.replicaset.servers[i]
	rservs.push(new mongo.Server(servconf.host,servconf.port,{native_parser:false,auto_reconnect:true}))
      }
      var rset = new mongo.ReplSetServers(rservs)
      dbinst = new mongo.Db(
	conf.name, rset
      )
    }
    else {
      dbinst = new mongo.Db(
        conf.name,
        new mongo.Server(
          conf.host || conf.server, 
          conf.port || mongo.Connection.DEFAULT_PORT, 
          {}
        ), 
        {native_parser:false,auto_reconnect:true}
      )
    }

    // FIX: error reporting sucks on login fail
    dbinst.open(function(err){
      if( !error({actid$:'init'},err,cb) ) {
        minwait = MIN_WAIT

        if( conf.username ) {

          dbinst.authenticate(conf.username,conf.password,function(err){
            // do not attempt reconnect on auth error
            if( err) {

var Db = require('mongodb').Db;
var Connection = require('mongodb').Connection;
var Server = require('mongodb').Server;
var connectionInstance;
var conf = require('../config/conf.js');
module.exports = function(callback) {
  //if already we have a connection, don't connect to database again
  if (connectionInstance) {
    callback(null,connectionInstance);
    return;
  }
		//db name		//db ip    db port
  var db = new Db(conf.DatabaseName, new Server(conf.mongoIp,conf.mongoPort,{ auto_reconnect: true }));
  db.open(function(error, databaseConnection) {
    //if (error) throw new Error(error);
    if (error){callback(error,null)}
    else{
      console.log("database connection successfully in connection class")

var fixtures = require('../mongodb-fixtures.js');

var Db = require('mongodb').Db,
  Connection = require('mongodb').Connection,
  Server = require('mongodb').Server;

var db = new Db('wines', new Server("localhost", Connection.DEFAULT_PORT, {}));

var data = fixtures.load();
fixtures.save(data, db, function() {
  db.close();
  console.dir(data);
});

var express = require('express'),
  Db = require('mongodb').Db,
  Server = require('mongodb').Server,
  Connection = require('mongodb').Connection,  
  http = require('http'),
  debug = require('util').debug,
  inspect = require('util').inspect;
  
var host = 'localhost';
var port = Connection.DEFAULT_PORT;
var db = new Db('node-mongo-examples', new Server(host, port, {}), {native_parser:false});

var ObjectID = db.bson_serializer.ObjectID;

var app = express.createServer(
  express.cookieParser(),
  express.bodyParser(),
  express.session({ secret: 'keyboard cat' })
);

var settings = require('../settings'),
    Db = require('mongodb').Db,
    Connection = require('mongodb').Connection,
    Server = require('mongodb').Server;
module.exports = new Db(settings.db, new Server(settings.host, settings.port), {safe: true});

var MongoDB = exports.MongoDB = function (options) {
  options = options || {}
  
  if (!options.db) { 
    throw new Error("Cannot log to MongoDB without database name.");
  }
  
  this.name = 'mongodb';
  this.db = options.db;
  this.host = options.host || 'localhost';
  this.port = options.port || mongodb.Connection.DEFAULT_PORT;
  this.collection = options.collection || "log";
  this.safe = options.safe || true;
  this.level = options.level || 'info';
  this.silent = options.silent || false;
};