Node.js
Agenda
- Install
- Hello World
- Ecosystem
- Single threaded
- Blocking IO
- Servers TCP/HTTP
- CTF
Install Node.js
http://nodejs.org
follow wizard
Installed?
$ node --version
v0.10.30REPL
$ node
>$ node
> var hello = "world";
undefined
>> hello
'world'
>Hello world!
var http = require('http');
var server = http.createServer(function(req, res){
res.end("Hello World");
});
server.listen("3000");
Node is
-
v8 JavaScript runtime
- Event driven
- Non-blocking standard libraries
- Extend with C/C++ addons
Node is not
-
A framework
-
A new programming language
What is Node used for?
Web servers
Desktop applications
CLI tools
Websites!
Desktop applications!
CLI tools
Why?
-
JavaScript everywhere!
-
Great community (NPM, sponsors)
Sweet Spots!
-
Real Time IO intensive apps
-
Speaks JSON
-
Easy to make APIs
Not so sweet..
-
Simple crud apps
-
CPU intensive stuff
Ecosystem
- NPM
- Bower
- Grunt
- Yeoman
- MongoDB (and other)
- Template engines
DEMO 1.5
What's taking so long?!
- L1-cache: 3 cycles
- L2-cache: 14 cycles
- RAM: 250 cycles
- Disk: 41 000 000 cycles
- Network: 240 000 000 cycles
So: what is non-blocking IO
with these facts in mind?
Sync vs. Async
Node runs on 1 thread only
Almost...
Disk operations and network requests are threaded.
But you can't interfere with those
DEMO 2!
First thing every programmer do...
cout << "Tell me your name: ";
cin >> name;
cout << "Hello " << name << endl;
Let's do that async
process.stdout.write("Tell me your name: ");
process.stdin.on('data', function(name){
console.log("Hello " + name);
});
WEBSERVERS!
TCP and HTTP
TCP
var tcp = require('net');
var server = tcp.createServer();
server.on('connection', function(connection){
console.log(connection);
});
server.listen(3000);
HTTP & DEMO 3
var http = require('http');
var server = http.createServer();
server.on('request', function(req, res){
res.end("You requested: " + req.headers.host);
});
server.listen(3000);
ORC API
var tcp = require('net');
var stdin = process.openStdin();
var client = tcp.connect('PORT', 'HOST/IP');
client.setEncoding('ENCODING');
stdin.addListener("data", function(d){ ... });
client.on('connect', function(){ ... });
client.write("STRING");
client.on('data', function(data){ ... });
IP: xx.xx.xx.xx
Port: 3000
"JOIN nickname"
Next time?
Connect
Express
Node.JS #1
By Gustav Jorlöv
