express + node_redis model

gistfile1.js

exports.exec = function(command,args){
	var util 	= require('util');
	var app 	= require('../app');
	var Q 		= require('q');
	
	var client 	 	= app.get('db');
	var deferred 	= Q.defer();
	
	client.send_command(command, args, function(error,result){
	    if (error) {
	        deferred.reject(new Error(error));
	    } else {
			console.log('redis return result = '+util.inspect(result, false, null));
			
	        deferred.resolve(result);
	    }
	});
	
	return deferred.promise;
}

exports.exec_once = function(command,args,cb_succuss,cb_error){
	return this.exec(command,args).then(function(data){
		if(cb_succuss){
			cb_succuss(data);
		}
	}).fail(function (error) {
		console.log('error = '+util.inspect(result, false, null));
	}).done();
}

exports.get_unique_userid_with_exec_once = function(cb_s,cb_e){
	return this.exec_once('INCR',"global:nextUserId",cb_s,cb_e);
};

exports.get_unique_userid_with_exec = function(res,cb_s,cb_e){
	return this.exec('INCR',"global:nextUserId").then(function(data){
		 res.send('respond with a resource' + data);
	}).fail(function (error) {
		console.log('error = '+util.inspect(result, false, null));
	}).done();
};