Ruby 2.0 on Rails in Production

Slides for RedDotRubyConf talk "Ruby 2.0 on Rails in Production" http://www.reddotrubyconf.com/schedule#amatsuda

Transcript

1. Ruby 2.0 on Rails
   in Production
   Akira
   Matsuda
   

   View Slide

2. % ruby -v
   
   Who here are already using
   Ruby 2.0 in production?
   

   View Slide

3. % ruby -v
   
   Who here are still using 1.8?
   

   View Slide

4. View Slide

5. begin
   

   View Slide

6. Ruby 2.0 goodness
   
   Performance
   
   Stability
   
   Compatibility
   
   New features
   

   View Slide

7. Performance
   

   View Slide

8. View Slide

9. ※ taken from @mirakui's slide at RubyKaigi 2013
   https://speakerdeck.com/mirakui/high-performance-rails?slide=7
   

   View Slide

10. ※ taken from @mrkn's slide at OedoRubyKaigi 03
    https://speakerdeck.com/mrkn/what-a-hard-work-to-make-the-recipe-
    sharing-service-available-on-ruby-1-dot-9-3?slide=128
    

    View Slide

11. rails command boot time
    # ruby 1.9.3p429
    % time rails r '1'
    rails r '1' 7.00s user 1.67s system 99% cpu 8.701 total
    % time rails r '1'
    rails r '1' 7.03s user 1.64s system 99% cpu 8.698 total
    % time rails r '1'
    rails r '1' 7.01s user 1.66s system 99% cpu 8.710 total
    # ruby 2.0.0p195
    % time rails r '1'
    rails r '1' 4.80s user 1.29s system 99% cpu 6.124 total
    % time rails r '1'
    rails r '1' 4.77s user 1.28s system 99% cpu 6.073 total
    % time rails r '1'
    rails r '1' 4.78s user 1.29s system 99% cpu 6.099 total
    

    View Slide

12. Stability
    

    View Slide

13. Stability
    
    Fact: 2.0.0 was a "stable" release
    

    View Slide

14. 1.9.0 was not
    
    1.9.0: unstable
    
    1.9.1: unstable
    
    1.9.2: stable
    
    1.9.3: stable
    
    2.0.0: stable
    
    2.1.0: stable (?)
    

    View Slide

15. Stability
    
    2.0.0-p195 was released last
    month by @nagachika
    

    View Slide

16. View Slide

17. View Slide

18. Stability
    
    2.0.0 is no more p0 and so
    it's ready to use in production
    

    View Slide

19. Branch Maintenance Policies
    
    1.8.7: maintained by @shyouhei, will be dead soon
    
    1.8.8: no plan
    
    1.9.0: dead
    
    1.9.1: dead
    
    1.9.2: maintained by @yugui, dead (?)
    
    1.9.3: maintained by @unak
    
    1.9.4: no plan
    
    2.0.0: maintained by @nagachika
    
    2.0.1: no plan
    
    2.1.0: managed by @naruse
    

    View Slide

20. 1.9.3
    
    Released by @yugui
    
    Maintained by @unak (aka. usa)
    
    Sponsored by Ruby Association
    

    View Slide

21. View Slide

22. View Slide

23. 2.0.0
    
    Released by @mametter (aka.
    mame)
    
    Maintained by @nagachika
    

    View Slide

24. View Slide

25. View Slide

26. 2.1.0
    
    Would be released by @nalsh
    (aka. naruse)
    
    Would be released in December
    this year
    

    View Slide

27. View Slide

28. "TRICK 2013" in RubyKaigi
    
    Results: http://
    www.slideshare.net/mametter/
    trick2013-results
    
    Winners: https://github.com/tric/
    trick2013
    

    View Slide

29. @unak (usa)
    $ruby.is_a?(Object){|oriented| language}
    

    View Slide

30. @mametter (mame)
    eval$C=%q(at_exit{
    open("/dev/dsp","wb"){|g|h=[0]*80
    $><<"\s"*18+"eval$C=%q(#$C);S=%:"
    (S<t=0; h.map!{|v|d=?!==l[
    t]?1 :(l[
    t]== ?#)?
    0*v= 6:03
    (v<1 ?[]:
    0..n -1).
    each {|z|
    s[z] +=2*
    M.sin(($*[0] ||1)
    .to_f*M.sin(y= 40*(z+m)*2**
    (t/12E0)/463)+ y)*(v-z*d/n)};
    t+=1;v-d};m+= n;g.flush<<(s.
    pack"C*"); puts(l)}}};M=
    Math);S=%:
    Jesu, Joy of Man's Desiring
    Johann Sebastian Bach
    #
    | #
    | #
    # # # #
    | | | #
    | | # #
    # # # #
    | | | #
    | | # #
    # # # #
    | | | #
    | | # #
    # # # #
    | | | #
    | | # #
    # # # #
    | | | #
    | | # #
    # # # #
    | | | #
    | | # #
    # # # #
    | | | #
    | | #
    # # # #
    | | | #
    | #| #
    # # | #
    | | | #
    | | # #
    # # # #
    | | # |
    | | # #
    # # # #
    | | | #
    | | #
    # # # #
    | | # |
    | # # |
    # # # #
    | | | #
    | | # #
    # # # #
    | | | #
    | | # #
    # # # #
    | | | #
    | | # #
    # # # #
    | | | #
    | | # #
    # # # #
    | | | #
    | | # #
    # # # #
    | | | #
    | | # #
    # # # #
    | | | #
    | # #
    # # #
    | | | #
    | # | #
    # # # #
    | | | |
    | | | |
    | | | |
    | | | |
    | | | |
    | | | |
    | | | |
    | | | |
    | | | |
    | | | |
    

    View Slide

31. Compatibility
    

    View Slide

32. Compatibility
    
    "100% compatible" (Ruby level)
    
    magic comment
    

    View Slide

33. View Slide

34. 99.9% compatible
    
    Default Ruby source le
    encoding to utf-8 [Feature #6679]
    

    View Slide

35. Hello!
    puts '͜Μʹͪ͸ʂ'
    

    View Slide

36. Hello...?
    % ruby -v hello_utf8.rb
    ruby 1.8.7 (2012-06-29 patchlevel 370) [i686-darwin12.2.1]
    ͜Μʹͪ͸ʂ
    % ruby -v hello_utf8.rb
    ruby 1.9.3p429 (2013-05-15 revision 40747) [x86_64-darwin12.3.0]
    encoding_utf8.rb:1: invalid multibyte char (US-ASCII)
    

    View Slide

37. Magic comment
    # encoding: utf-8
    puts '͜Μʹͪ͸ʂ'
    

    View Slide

38. ͜Μʹͪ͸ɺ1.9.3!
    % ruby -v hello_utf8.rb
    ruby 1.9.3p429 (2013-05-15 revision 40747) [x86_64-darwin12.3.0]
    ͜Μʹͪ͸ʂ
    

    View Slide

39. Hello!
    puts '͜Μʹͪ͸ʂ'
    

    View Slide

40. Hello...?
    % ruby -v hello_utf8.rb
    ruby 1.8.7 (2012-06-29 patchlevel 370) [i686-darwin12.2.1]
    ͜Μʹͪ͸ʂ
    % ruby -v hello_utf8.rb
    ruby 1.9.3p429 (2013-05-15 revision 40747) [x86_64-darwin12.3.0]
    encoding_utf8.rb:1: invalid multibyte char (US-ASCII)
    % ruby -v hello_utf8.rb
    ruby 2.0.0p195 (2013-05-14 revision 40734) [x86_64-darwin12.3.0]
    ͜Μʹͪ͸ʂ
    

    View Slide

41. Incompatibility
    s = "\xE3\x81\x82"
    p s, s.size
    

    View Slide

42. Incompatibility
    % ruby -v encoding_binary.rb
    ruby 1.9.3p429 (2013-05-15 revision 40747) [x86_64-darwin12.3.0]
    "\xE3\x81\x82"
    3
    % ruby -v encoding_binary.rb
    ruby 2.0.0p195 (2013-05-14 revision 40734) [x86_64-darwin12.3.0]
    "͋"
    1
    

    View Slide

43. Tiny Print Debugging Tip
    s = "\xE3\x81\x82"
    # p s, s.size
    p str: s, size: s.size
    

    View Slide

44. Tiny Print Debugging Tip
    % ruby encoding_binary.rb
    {:str=>"͋", :size=>1}
    (by @yhara: http://route477.net/d/?date=20130206#p01)
    

    View Slide

45. Compatibility (GC bug)
    
    Ruby 2.0 is so compatible with
    1.9.3 that even known bugs are
    compatible!
    

    View Slide

46. "GC.disable_lazy_sweep"
    
    https://gist.github.com/mrkn/
    5096076
    

    View Slide

47. New features
    

    View Slide

48. New Features
    
    (Re nements)
    
    Module#prepend
    
    Keyword arguments
    
    Enumerable#lazy
    

    View Slide

49. Re nements
    

    View Slide

50. View Slide

51. Module#prepend
    

    View Slide

52. Module#prepend
    
    Good for Rails plugins
    
    You can replace
    alias_method_chain with this
    

    View Slide

53. AMC
    class A
    def foo
    puts 'foo'
    end
    end
    class A
    def foo_with_bar
    foo_without_bar
    puts ‘bar’
    end
    alias_method_chain :foo, :bar
    end
    A.new.foo
    #=> foo
    bar
    

    View Slide

54. Module#prepend
    class A
    def foo; puts 'foo'; end
    end
    module Bar
    def foo
    super
    puts 'bar'
    end
    end
    class A
    prepend Bar
    end
    A.new.foo
    #=> foo
    bar
    

    View Slide

55. Keyword arguments
    

    View Slide

56. Method#parameters
    
    since 1.9.1
    

    View Slide

57. Method#parameters
    class C
    def m(a, b = 1, c = nil) end
    end
    C.new.method(:m).parameters
    #=> [[:req, :a], [:opt, :b], [:opt, :c]]
    

    View Slide

58. asakusarb/action_args
    

    View Slide

59. View Slide

60. Initial implementation
    module AbstractController
    class Base
    def send_action(method_name, *args)
    return send method_name, *args unless args.blank?
    values =
    method(method_name).parameters.map(&:last).map {|k|
    params[k]}
    send method_name, *values
    end
    end
    end
    

    View Slide

61. Test Patterns
    params = {a: '1', b: '2'}
    def m end
    #=> []
    def m(a) end
    #=> ['1']
    def m(a = 'a') end
    #=> ['1']
    def m(c = 'c') end
    #=> expected: ['c'], actual: [nil]
    

    View Slide

62. Don't add to the arguments if (type
    == :opt) && !params.has_key?
    params = {a: '1', b: '2'}
    def m(c = 'c') end
    #=> ['c']
    def m(a, b) end
    #=> ['1', '2']
    def m(a, b = 'b') end
    #=> ['1', '2']
    def m(a, c = 'c') end
    #=> ['1', 'c']
    def m(a = 'a', b = 'b') end
    #=> ['1', '2']
    def m(c = 'c', d = 'd') end
    #=> ['c', 'd']
    def m(c = 'c', a) end
    #=> expected: ['c', '1'], actual: ['1']
    

    View Slide

63. Default value can't be determined in
    parse / compile phase
    def foo(x = rand(3))
    

    View Slide

64. RubyVM::InstructionSequence
    # warning: Do never use this black magic!!
    def foo(x = 'xx', y = :yy, z = 1); end
    ary = RubyVM::InstructionSequence.of(method(:foo)).to_a
    default_args = ary[11][1]
    bytecode = ary[13]
    p default_args
    #=> [:label_0, :label_4, :label_8, :label_11]
    p bytecode
    #=> [:label_0, 2, [:putstring, "xx"],
    [:setlocal_OP__WC__0, 4], :label_4, [:putobject, :yy],
    [:setlocal_OP__WC__0, 3], :label_8,
    [:putobject_OP_INT2FIX_O_1_C_], [:setlocal_OP__WC__0,
    2], :label_11, [:trace, 8], [:putnil], [:trace, 16],
    [:leave]]
    

    View Slide

65. method.parameters.reverse_each do |type, key|
    do the same thing
    params = {a: '1', b: '2'}
    def m(c = 'c', a) end
    => ['c', '1']
    

    View Slide

66. We needed to do this because,
    
    Method parameters are just an
    Array
    
    So the order matters
    
    It's a pain
    
    I wish if the method parameter is
    more like a Hash, labeled by the
    de ned method argument names
    

    View Slide

67. OK, that's called "Keyword arguments"
    

    View Slide

68. Keyword arguments
    # traditional method
    def m(a, b = 'b', c = 'c') end
    m('1', '2', '3')
    # kwargs
    def m(a, b: 'b', c: 'c') end
    m('1', b: '2', c: '3')
    

    View Slide

69. Keyword arguments
    
    Optional parameters can be
    written as a Hash. Order doesn't
    matter
    
    action_args now supports
    kwargs, so you can use it in your
    controller code
    

    View Slide

70. kwargs and Rails
    
    Rewriting Rails code using kwargs
    
    More comprehensible API
    def foo(options_with_some_unknown_keys_and_defaults = {})
    def bar(*values_maybe_or_maybe_not_with_options)
    ⊗
    def foo(x: 1, y: 2, z: 2)
    def bar(*values, **options)
    

    View Slide

71. kwargs and Rails (AS)
    # AS/lib/active_support/core_ext/class/attribute_accessors.rb
    - def cattr_reader(*syms)
    - options = syms.extract_options!
    + def cattr_reader(*syms, instance_reader: true, instance_accessor:
    true)
    ...
    - unless options[:instance_reader] == false ||
    options[:instance_accessor] == false
    + unless (instance_reader == false) || (instance_accessor ==
    false)
    

    View Slide

72. kwargs and Rails (AMo)
    # AMo/lib/active_model/validations/validates.rb
    - def validates(*attributes)
    - defaults = attributes.extract_options!.dup
    + def validates(*attributes, **defaults)
    

    View Slide

73. kwargs and Rails (AP)
    # AP/lib/action_view/helpers/text_helper.rb
    - def cycle(first_value, *values)
    - options = values.extract_options!
    - name = options.fetch(:name, 'default')
    -
    + def cycle(first_value, *values, name: 'default')
    

    View Slide

74. A pitfall I found
    

    View Slide

75. kwargs and Rails (:if, :unless)
    User.validates_presence_of :name, :if => -> { true }
    # AMo/lib/active_model/validations/presence.rb
    - def validates_presence_of(*attr_names)
    + def validates_presence_of(*attr_names, if: true, unless:
    false, on: nil, strict: nil)
    

    View Slide

76. :if!?
    def m(if: true)
    end
    

    View Slide

77. :if!?
    def m(if: true)
    if if
    ...
    end
    end
    #=> "syntax error, unexpected keyword_end"
    

    View Slide

78. :if!?
    def m(if: true)
    p if
    end
    #=> "syntax error, unexpected keyword_end"
    

    View Slide

79. kwargs and Rails (:end)
    

    View Slide

80. kwargs and Rails (:end)
    # actionpack/lib/action_view/helpers/date_helper.rb
    - def build_options(selected, options = {})
    - options = {
    - leading_zeros: true, ampm: false,
    use_two_digit_numbers: false
    - }.merge!(options)
    -
    - start = options.delete(:start) || 0
    - stop = options.delete(:end) || 59
    - step = options.delete(:step) || 1
    - leading_zeros = options.delete(:leading_zeros)
    + def build_options(selected, start: 0, end: 59, step: 1,
    leading_zeros: true, ampm: false, use_two_digit_numbers: false)
    

    View Slide

81. :end!?
    def m(end: 'omg')
    p end
    end
    #=> "syntax error, unexpected keyword_end, expecting end-of-input"
    

    View Slide

82. Enumerable#lazy
    

    View Slide

83. Enumerable#lazy
    "Enumerable#lazy".topics.lazy.each {|it| I.talk it}
    

    View Slide

84. New Features (internal)
    
    TracePoint
    
    DTrace support
    
    caller_locations
    
    debug_inspector API
    
    Memory inspection features
    

    View Slide

85. View Slide

86. debug_inspector API
    

    View Slide

87. The "debugger" gem
    
    Works on Ruby 1.9
    
    Partly supports 2.0
    
    Own header les
    

    View Slide

88. We created a new gem
    
    Named it "debugger2"
    (ko1 named it. Not me!)
    
    Based on new debugger API
    

    View Slide

89. Debugger2 gem
    
    "1.0.0.beta2"
    
    Still buggy on Rails
    
    We need to do more debugging
    on the debugger...
    

    View Slide

90. We want debugger!!!
    

    View Slide

91. end
    

    View Slide