![NOW IN RUBY
require 'rubygems'
require 'mongrel'
class HelloWorldHandler < Mongrel::HttpHandler
def process(request, response)
sleep a2
response.start(200) do |head,out|
head["Content-Type"] = "text/plain"
out.write(“Hello World”)
end
end
end
h = Mongrel::HttpServer.new("127.0.0.1", "1337")
h.register("/", HelloWorldHandler.new)
h.run.join
$ ab –n 200 -c 50 http://localhost:1337/](https://image.slidesharecdn.com/introductiontonode-1-111119070815-phpapp01/85/Introduction-to-node-js-20-320.jpg)
![USING V8
String::New(“a = 1; b = 2; a + b”)
$ ./hello-world
String::New(ARGV[1])
$./hello-world “a = 1; b = 2; a + b”
String::New(fread(ARGV[1]))
$./hello-world hello-world.js](https://image.slidesharecdn.com/introductiontonode-1-111119070815-phpapp01/85/Introduction-to-node-js-42-320.jpg)
Introduction to node.js
- 1. Introduction to Node.js By Arun Kumar Arjunan, Product Architect, Chronus
- 2. AGENDA • About Node.js • Programming in Node.js • Web Frameworks • Node.js internals • Popularity of Node.js • Downside of Node.js
- 5. node.js KO
- 6. NIDE
- 7. Chess@home
- 8. GITJS GitJS is a pure JavaScript implementation Of Git. Example Commands: • git.js log • git.js branch • git.js show SHA
- 9. NODECHAT
- 10. DEFINITION Node.js is an event-driven I/O server-side JavaScript environment
- 11. AGENDA • About Node.js Programming in Node.js • Web Frameworks • Node.js internals • Popularity of Node.js • Downside of Node.js
- 12. HELLO WORLD PROGRAM Node.JS is a command line tool $ node hello-console.js
- 13. HTTP SERVER
- 14. FILE SYSTEM
- 15. OTHER LIBRARIES • Timers • DNS • Events • REPL • Buffers • Child Processes • Streams • ZLIB • Crypto • OS • TLS/SSL
- 16. NODE IS EVENT DRIVEN Did you notice that the previous examples use Event Driven technique?
- 17. NODE IS EVENT DRIVEN
- 18. NODE IS EVENT DRIVEN
- 19. NODE IS EVENT DRIVEN $ ab –n 200 -c 50 http://localhost:8080/
- 20. NOW IN RUBY require 'rubygems' require 'mongrel' class HelloWorldHandler < Mongrel::HttpHandler def process(request, response) sleep a2 response.start(200) do |head,out| head["Content-Type"] = "text/plain" out.write(“Hello World”) end end end h = Mongrel::HttpServer.new("127.0.0.1", "1337") h.register("/", HelloWorldHandler.new) h.run.join $ ab –n 200 -c 50 http://localhost:1337/
- 21. EVENT DRIVEN VS THREADING Lets compare Event Driven Programming & Thread based programming!!! • Some theory proves Threading model is better • Some proves Event Driven Programming is better
- 22. EVENT DRIVEN VS THREADING Lets take an example that is relevant to us!!!
- 23. APACHE VS NGINX
- 24. APACHE VS NGINX
- 25. APACHE VS NGINX The difference? Apache uses one thread per connection. NGINX doesn’t use threads. It uses an event loop
- 26. Disadvantages of Threading • Context switching is not free • Execution stacks take up memory • For massive concurrency, cannot use an OS thread for each connection.
- 27. AGENDA • About Node.js • Programming in Node.js Web Frameworks • Node.js internals • Popularity of Node.js • Downside of Node.js
- 28. NODE.JS COMMUNITY Node.js has excellent community
- 29. NODE PACKAGE MANAGER NPM Its like bundler for Ruby Gems
- 30. AROUND 60 TEMPLATE ENGINES asyncEJS, bake, bind-js, blue, CoffeeKup, combyne.js, doT.js, dust, Eco, ejs, haml.js, haml-js, jshtml, jqtpl, Jade, jazz, JinJS, JSON Template, jm, jsdom, less.js, Liquor, minimal.js, Mu, nTPL, nodejs-meta-templates, normal-template, nun, node.magic_dom, node-template, node-properties, Parrot, PURE, stencil, Node-T, Swig, Templ8, template.node.js, tmpl-node, TwigJS, weld
- 31. WEB FRAMWEORKS 1. Geddy 2. ExpressJS 3. RailwayJS
- 32. RAILWAYJS Quick guide to RailwayJS Its like Rails itself
- 36. AGENDA • About Node.js • Programming in Node.js • Web Frameworks • Node.js Internals • Popularity of Node.js • Downside of Node.js
- 38. ABOUT V8 • V8 team is led by Lars Bak • Lars Bak was the technical lead behind HotSpot (Sun’s Java VM). • HotSpot improved Java’s performance 20x times • Before HotSpot Lars Bak worked on a Smalltalk VM • V8 uses hidden classes
- 39. UNDERSTANDING V8 Lets try to understand V8
- 40. UNDERSTANDING V8 • It is used to run JavaScript • Can be embedded into any application • Can expose C methods & Objects using JS interface
- 41. USING V8
- 42. USING V8 String::New(“a = 1; b = 2; a + b”) $ ./hello-world String::New(ARGV[1]) $./hello-world “a = 1; b = 2; a + b” String::New(fread(ARGV[1])) $./hello-world hello-world.js
- 43. NODE.JS ADVANTAGES So Node.Js is nothing but a set of libraries using V8 engine
- 44. AGENDA • About Node.js • Programming in Node.js • Web Frameworks • Node.js Internals • Popularity of Node.js • Downside of Node.js
- 45. NODE.JS ADVANTAGES • Server side Javascript • Javascript is dynamic • Event based • Learning curve is less • Suited for event driven programming • Uses V8 which relatively faster • Uses CommonJS module spec
- 46. NODE.JS ADVANTAGES Is the server side JavaScript programming new?
- 47. SERVER SIDE JS FRAMEWORKS • Helma - Rhino • AppJet - Rhino • Aptana Jaxer - SpiderMonkey • CouchDB - SpiderMonkey
- 48. NODE.JS ADVANTAGES Is the Event Driven programming new?
- 49. EVENT DRIVEN PROGRAMMING LANGUAGES • E Programming language • Event Driven MVC Framework for SmallTalk • AmbientTalk
- 50. Similar Frameworks • Event Machine for Ruby • Libevent for C • Twisted for Python
- 51. Conclusion So why is Node.js so popular?
- 52. Conclusion I think its because Ryan Dhal put cool things together!!!
- 53. AGENDA • About Node.js • Programming in Node.js • Web Frameworks • Node.js Internals • Popularity of Node.js • Downside of Node.js
- 54. NODE.JS COMPLAINTS • Programmers are used to synchronous code • Exceptions are hard to handle • Difficult to debug • Most importantly it is not matured yet • Doesn’t utilize multi-core CPU
- 55. Conclusion FUTURE OF NODE.JS ???