Humans Networks and Chaos

An introduction to Node.js

Transcript

1. Node.js an introduction to Humans,Networks and Chaos Monday, 13 February 12
2. Don’t believe Hype The Monday, 13 February 12
3. Chat! Let’s Monday, 13 February 12
4. >10 PRINT "HELLO LWSG!"; >20 GOTO 10 Monday, 13 February 12
5. Room You are in a with 2 exits Left or right? Monday, 13 February 12
6. Input / Output Logic Left You found the Princess! Monday, 13 February 12
7. Map scenarios Write code Easy! Monday, 13 February 12
8. Scenario: Player Turns Left Given I am asked to turn left or right When I choose to turn left Then I should see “Eaten by a dragon” Scenario: Player Turns Right Given I am asked to turn left or right When I choose to turn left Then I should see “You found the Princess” Monday, 13 February 12
9. Stop playing with yourself. Monday, 13 February 12
10. Stop playing with yourself. More difficult. Monday, 13 February 12
11. Atari Joystick Joystick Input(s) Logic Output Monday, 13 February 12
12. 8 way joystick 2 buttons 2 players Monday, 13 February 12
13. 8 way joystick 2 buttons 2 players Unpredictable Humans Monday, 13 February 12
14. Xbox Controller Internet Map scenarios for this Game Servers Databases Chat Servers Voice Servers Load balancers Message queues .. more 8 million controllers Monday, 13 February 12
15. Concurrency Fork Synchronous Threads Single-thread Events Monday, 13 February 12
16. Concurrency This is hard Node.js is a response Monday, 13 February 12
17. Events Browsers Humans It works. JavaScript Monday, 13 February 12
18. Event loop Single threaded Don’t block Return fast Monday, 13 February 12
19. thread One Monday, 13 February 12
20. thread One INSANE? Are YOU And JavaScript? Monday, 13 February 12
21. Performance http://blog.webfaction.com/a-little-holiday-present Monday, 13 February 12
22. Memory http://blog.webfaction.com/a-little-holiday-present Monday, 13 February 12
23. Web is changing (again) The Monday, 13 February 12
24. Network EVERYTHING Phones Tablets TVs Monday, 13 February 12
25. Toasters Bus stops Cars Billboards Fridges Network EVERYTHING APIs Monday, 13 February 12
26. Turn left or right? Server Browser Monday, 13 February 12
27. Still ok? Server Browser DB Server Monday, 13 February 12
28. Still ok? Browser Server App Servers Databases Chat Servers Voice Servers Load balancers Message queues 3rd party APIs ..more Unlimited things Millions of users. Phones, Tablets, TVs Billboards, Fridges more.. Monday, 13 February 12
29. Chaos Data flow Networks Monday, 13 February 12
30. Chaos Data flow Humans Networks Monday, 13 February 12
31. Push Real-time Networked High concurrency Monday, 13 February 12
32. I/O event-driven Non-blocking Monday, 13 February 12
33. I/O event-driven Non-blocking What? Monday, 13 February 12
34. With Javascript. @hij1nx That is all. Network programming. Monday, 13 February 12
35. V8 Brains FAST Networks Performance Monday, 13 February 12
36. JavaScript EVENTED JSON Browsers Mis- Well understood Monday, 13 February 12
37. var http = require('http'); http.createServer(function (req, res) { res.writeHead(200, {'Content-Type': 'text/plain'}); res.end('Hello World\n'); }).listen(1337, "127.0.0.1"); console.log('Server running at http:// 127.0.0.1:1337/'); HelloWorld Monday, 13 February 12
38. HelloWorld var http = require('http'); http.createServer(function (req, res) { res.writeHead(200, {'Content-Type': 'text/plain'}); res.end('Hello World\n'); }).listen(1337, "127.0.0.1"); console.log('Server running at http:// 127.0.0.1:1337/'); Monday, 13 February 12
39. Callbacks Do something when you FINISH Monday, 13 February 12
40. $("p").hide(1000); alert("The paragraph is now hidden"); $("p").hide(1000,function(){ alert("The paragraph is now hidden"); }); Callbacks in jQuery Monday, 13 February 12
41. var urls = db.query("select * from urls"); urls.each(function () { var page = http.get(url); save(page); }); db.query("select * from urls", function (urls) { urls.each(function(url) { http.get(url, function (page) { save(page); }); }); }); Jacek Becela http://www.slideshare.net/jacekbecela/introduction-to-nodejs Monday, 13 February 12
42. var urls = db.query("select * from urls"); urls.each(function () { var page = http.get(url); save(page); }); db.query("select * from urls", function (urls) { urls.each(function(url) { http.get(url, function (page) { save(page); }); }); }); http://www.slideshare.net/jacekbecela/introduction-to-nodejs Blocking Blocking Blocking Monday, 13 February 12
43. var urls = db.query("select * from urls"); urls.each(function () { var page = http.get(url); save(page); }); db.query("select * from urls", function (urls) { urls.each(function(url) { http.get(url, function (page) { save(page); }); }); }); http://www.slideshare.net/jacekbecela/introduction-to-nodejs Blocking Blocking Blocking Callbacks Monday, 13 February 12
44. Head Hurts Show Me something FUN Monday, 13 February 12
45. Forget order Embrace Random Events Monday, 13 February 12
46. Where next? Express (gateway drug) - http://expressjs.com Socket.io (fast high) - http://socket.io/ dnode (blows mind) - https://github.com/substack/dnode UK Training http://leftlogic.com/training#node Monday, 13 February 12
47. Thanks! @shapeshed Slides: bit.ly/A8azQ7 Monday, 13 February 12