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
2. % ruby -v Who here are already using Ruby 2.0 in production?
3. % ruby -v Who here are still using 1.8?
5. begin
6. Ruby 2.0 goodness Performance Stability Compatibility New features
7. Performance
9. ※ taken from @mirakui's slide at RubyKaigi 2013 https://speakerdeck.com/mirakui/high-performance-rails?slide=7
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
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
12. Stability
13. Stability Fact: 2.0.0 was a "stable" release
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 (?)
15. Stability 2.0.0-p195 was released last month by @nagachika
18. Stability 2.0.0 is no more p0 and so it's ready to use in production
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
20. 1.9.3 Released by @yugui Maintained by @unak (aka. usa) Sponsored by Ruby Association
23. 2.0.0 Released by @mametter (aka. mame) Maintained by @nagachika
26. 2.1.0 Would be released by @nalsh (aka. naruse) Would be released in December this year
28. "TRICK 2013" in RubyKaigi Results: http:// www.slideshare.net/mametter/ trick2013-results Winners: https://github.com/tric/ trick2013
29. @unak (usa) $ruby.is_a?(Object){|oriented| language}
30. @mametter (mame) eval$C=%q(at_exit{ open("/dev/dsp","wb"){|g|h=[0]*80 $><<"\s"*18+"eval$C=%q(#$C);S=%:" (S<<m=58).lines{|l|s=[128]*n=20E2 t=0; h.map!{|v|d=?!==l[ t]?1 :(l[ t]== ?#)? 0*v= 6:03 (v<1 ?[]: 0..n -1). each {|z| s[z] +=2* M.sin(($*[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 # | # | # # # # # | | | # | | # # # # # # | | | # | | # # # # # # | | | # | | # # # # # # | | | # | | # # # # # # | | | # | | # # # # # # | | | # | | # # # # # # | | | # | | # # # # # | | | # | #| # # # | # | | | # | | # # # # # # | | # | | | # # # # # # | | | # | | # # # # # | | # | | # # | # # # # | | | # | | # # # # # # | | | # | | # # # # # # | | | # | | # # # # # # | | | # | | # # # # # # | | | # | | # # # # # # | | | # | | # # # # # # | | | # | # # # # # | | | # | # | # # # # # | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | | |
31. Compatibility
32. Compatibility "100% compatible" (Ruby level) magic comment
34. 99.9% compatible Default Ruby source le encoding to utf-8 [Feature #6679]
35. Hello! puts '͜Μʹͪ͸ʂ'
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)
37. Magic comment # encoding: utf-8 puts '͜Μʹͪ͸ʂ'
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
39. Hello! puts '͜Μʹͪ͸ʂ'
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
41. Incompatibility s = "\xE3\x81\x82" p s, s.size
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
43. Tiny Print Debugging Tip s = "\xE3\x81\x82" # p s, s.size p str: s, size: s.size
44. Tiny Print Debugging Tip % ruby encoding_binary.rb {:str=>"͋", :size=>1} (by @yhara: http://route477.net/d/?date=20130206#p01)
45. Compatibility (GC bug) Ruby 2.0 is so compatible with 1.9.3 that even known bugs are compatible!
46. "GC.disable_lazy_sweep" https://gist.github.com/mrkn/ 5096076
47. New features
48. New Features (Re nements) Module#prepend Keyword arguments Enumerable#lazy
49. Re nements
51. Module#prepend
52. Module#prepend Good for Rails plugins You can replace alias_method_chain with this
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
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
55. Keyword arguments
56. Method#parameters since 1.9.1
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]]
58. asakusarb/action_args
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
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]
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']
63. Default value can't be determined in parse / compile phase def foo(x = rand(3))
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]]
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']
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
67. OK, that's called "Keyword arguments"
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')
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
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)
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)
72. kwargs and Rails (AMo) # AMo/lib/active_model/validations/validates.rb - def validates(*attributes) - defaults = attributes.extract_options!.dup + def validates(*attributes, **defaults)
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')
74. A pitfall I found
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)
76. :if!? def m(if: true) end
77. :if!? def m(if: true) if if ... end end #=> "syntax error, unexpected keyword_end"
78. :if!? def m(if: true) p if end #=> "syntax error, unexpected keyword_end"
79. kwargs and Rails (:end)
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)
81. :end!? def m(end: 'omg') p end end #=> "syntax error, unexpected keyword_end, expecting end-of-input"
82. Enumerable#lazy
83. Enumerable#lazy "Enumerable#lazy".topics.lazy.each {|it| I.talk it}
84. New Features (internal) TracePoint DTrace support caller_locations debug_inspector API Memory inspection features
86. debug_inspector API
87. The "debugger" gem Works on Ruby 1.9 Partly supports 2.0 Own header les
88. We created a new gem Named it "debugger2" (ko1 named it. Not me!) Based on new debugger API
89. Debugger2 gem "1.0.0.beta2" Still buggy on Rails We need to do more debugging on the debugger...
90. We want debugger!!!
91. end