The document discusses The Ruby Racer, which embeds the V8 JavaScript interpreter into the Ruby process. This allows JavaScript code to be evaluated from Ruby, and for Ruby code and objects to be accessed from JavaScript. It enables features like headless JavaScript unit testing, tapping into Node.js utilities, and allowing client-side and server-side code sharing through templating, validation and business logic. Challenges include garbage collection across languages, but the technology aims to be robust, secure, efficient and cross-platform in the future.

1. The Ruby Racer
Under the Hood
Charles Lowell
@cowboyd

2. The Ruby Racer
Embeds the V8 JavaScript interpreter into your Ruby
process

3. Buzz!

4. Buzz! Rails 3.1

5. Buzz! Rails 3.1
by default

6. Buzz! Rails 3.1
by default
ExecJS (compile)

7. Buzz! Rails 3.1
by default
ExecJS (compile)
The Ruby Racer

8. But that’s just the cool
kids

9. But that’s just the cool
kids
why else?

10. Headless JavaScript
Unit Testing

11. Headless JavaScript
Unit Testing
Our first use at the FrontSide

12. Tap into Node.js
utilities

13. Tap into Node.js
utilities
less.js, handlebars.js, asciimo.js, jsdom.js, etc....

14. Client/Server code-
sharing

15. Client/Server code-
sharing
templating, validation, business logic

16. Performance

17. Performance
Re-implementing hotspots with V8 can be just as fast as
with C.

18. Performance
Re-implementing hotspots with V8 can be just as fast as
with C.
(but without C)

19. Performance
Re-implementing hotspots with V8 can be just as fast as
with C.
(but without C)
Yay!

20. The Ruby Racer
What does embedding a JavaScript interpreter into
your Ruby process mean?

21. Evaluate JavaScript from
Ruby

22. Evaluate JavaScript from
Ruby

23. Access JavaScript
Objects from Ruby

24. V8::Object

25. V8::Object
Every JS Object looks kinda like a Ruby hash

26. V8::Object
Every JS Object looks kinda like a Ruby hash

27. V8::Object
symbol/string agnostic

28. V8::Object
symbol/string agnostic

29. V8::Object
steez: attr_reader

30. V8::Object
steez: attr_reader

31. V8::Object
writeable? yes.

32. V8::Object
writeable? yes.

33. V8::Object
Enumerable? totally!

34. V8::Object
Enumerable? totally!

35. V8::Object
Enumerable? totally!

36. V8::Object
Methods? no, but yes.

37. V8::Object
Methods? no, but yes.
In JavaScript, methods are just properties that
happen to be functions

38. V8::Object
Methods? no, but yes.
In JavaScript, methods are just properties that
happen to be functions
JavaScript function calls are “richer”

39. V8::Function
call it like a proc

40. V8::Function
call it like a proc

41. V8::Function
call it like a method

42. V8::Function
call it like a method

43. V8::Function
call it like a constructor

44. V8::Function
call it like a constructor

45. V8::Object
Methods? no, but yes.
In JavaScript, methods are just properties that
happen to be functions

46. Methodish

47. Call JavaScript from
Ruby

48. Call JavaScript from
Ruby
• eval() js code directly

49. Call JavaScript from
Ruby
• eval() js code directly
• fiddle directly with js objects

50. Call JavaScript from
Ruby
• eval() js code directly
• fiddle directly with js objects
• fiddle directly with js functions

51. Call Ruby code from
JavaScript

52. Call Ruby code from
JavaScript

53. Call Ruby
bound methods

54. Call Ruby
bound methods

55. Call Ruby
procs/lambdas

56. Call Ruby
procs/lambdas

57. Call Ruby
Embed Classes

58. Call Ruby
Extend Classes

59. Ruby Properties

60. Properties
attr_reader

61. Properties
attr_reader

62. Properties
attr_accessor

63. Properties
attr_accessor

64. Properties
Dynamic (hashish)

65. Properties
Dynamic (hashish)

66. Properties
Dynamic (hashish)

67. Properties
Dynamic (hashish)
method_missing() !

68. Access Ruby Code
• call ruby methods
• fiddle with ruby properties
• dynamically fiddle with ruby properties

69. The Ruby Racer
In the year 3000

70. Safe eval()

71. Safe eval()

72. Safe eval()

73. Safe eval()

74. Other Stuff
• Multi threaded
• Custom Heap Snapshots
• Multiple V8 virtual machines per Ruby
Process

75. Challenges

76. Challenges
• garbage collection

77. Challenges
• garbage collection
• garbage collection

78. Challenges
• garbage collection
• garbage collection
• garbage collection

79. The Ruby Racer
in the year 3000
• Robust, Secure, Efficient
• JRuby, Rbx, MRI
• Cross platform (wherever ruby+v8 run)
• Binary gems everywhere

80. The Ruby Racer
in the year 3000
Where do you want
to go?

81. The Ruby Racer
• github.com/cowboyd/therubyracer
• irc://irc.freenode.net/therubyracer
• therubyracer@googlegroups.com