Nodejs Intro
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Node.js is a JavaScript runtime built on Chrome's V8 JavaScript engine. It uses an event-driven, non-blocking I/O model that makes it lightweight and efficient, enabling its use for real-time web applications. Node.js allows JavaScript code to run on the server, facilitating the creation of fast and scalable network applications like web servers through its asynchronous and event-driven architecture.
Nodejs Intro
- 1. Node.js “Because nothing blocks, less-than-expert programmers are able to develop fast systems.” http://nodejs.org/#about 04/2010 Rocco Georgi, PavingWays Ltd.
- 2. Node.js written in C and JavaScript I/O framework evented non-blocking server-side JavaScript CommonJS module system using V8 04/2010 Rocco Georgi, PavingWays Ltd.
- 3. written in C ./configure make make install #> node myfile.js 04/2010 Rocco Georgi, PavingWays Ltd.
- 4. I/O network I/O file I/O * I/O 04/2010 Rocco Georgi, PavingWays Ltd.
- 5. evented var tcp = require('tcp'); var server = tcp.createServer(function (socket) { socket.setEncoding("utf8"); event handlers socket.addListener("connect", function () { socket.send("hellorn"); for anything }); socket.addListener("receive", function (data) { event loop }); socket.send(data); no threads socket.addListener("eof", function () { socket.send("goodbyern"); socket.close(); }); }); server.listen(7000, "localhost"); 04/2010 Rocco Georgi, PavingWays Ltd.
- 6. non-blocking I/O is never blocking anything callbacks on anything everything in a single thread + loop very small memory footprint 04/2010 Rocco Georgi, PavingWays Ltd.
- 7. server-side JS V8 engine CommonJS: file = module // this loads circle.js and the sys object var circle = require('./circle'); var sys = require('sys'); // use the sys and circle object sys.puts('circle area at radius 4 = ' + circle.area(4)); no window object 04/2010 Rocco Georgi, PavingWays Ltd.
- 8. Benefits low memory footprint per connection high concurrency “hanging” requests -> Comet custom TCP/HTTP servers active module community e.g. WebSockets server 04/2010 Rocco Georgi, PavingWays Ltd.