Fixing a performance issue with the mustache gem

Fixing a performance issue with the mustache gem

@alicebartlett and I gave this talk at LRUG, on Monday 12th October 2015.

76b802165c7c55b9c719495d5e4dbf48?s=128

Dominic Baggott

October 12, 2015
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Transcript

  1. 4.

    In this talk: - Adding a feature - Finding a

    bug - working around the bug - fixing the bug
  2. 8.

    This is search within a manual A list of results

    from a Manual with a nested list of results from the rest of GOV.UK
  3. 11.
  4. 17.

    Using partials in this way is in the docs: from:

    https://mustache.github.io/mustache.5.html#Partials
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    -

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    -

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    -

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    # Profile the code RubyProf.start ... [code to profile] ...

    result = RubyProf.stop # Print a flat profile to text printer = RubyProf::FlatPrinter.new(result) printer.print(STDOUT) Measuring code with ruby-prof is easy
  11. 33.

    Profile of our code %self total self wait child calls

    name 5.41 0.271 0.086 0.000 0.185 675 Mustache::Parser#scan_tags 3.90 0.062 0.062 0.000 0.000 36 BasicObject#instance_eval 3.34 1.031 0.053 0.000 0.978 1 ActionView::CompiledTemplates#_app 2.98 0.047 0.047 0.000 0.000 6 <Class::Dir>#[] 2.52 0.042 0.040 0.001 0.001 74 <Module::ActiveSupport::Multibyte> 2.36 0.040 0.037 0.000 0.002 1095 Mustache::Parser#regexp 2.08 0.051 0.033 0.000 0.018 46 <Module::Marshal>#load 1.99 0.032 0.032 0.000 0.000 6 Kernel#require 1.98 0.032 0.032 0.000 0.000 2181 String#to_s 1.67 0.506 0.027 0.000 0.480 1007 *Array#each 1.55 0.050 0.025 0.000 0.025 972 Psych::ScalarScanner#tokenize 1.48 0.024 0.024 0.000 0.000 168 <Class::File>#exist? 1.35 0.068 0.021 0.000 0.046 663 Mustache::Parser#position 1.31 0.066 0.021 0.000 0.045 675 Mustache::Parser#scan_text
  12. 34.

    Profile of our code %self total self wait child calls

    name 5.41 0.271 0.086 0.000 0.185 675 Mustache::Parser#scan_tags 3.90 0.062 0.062 0.000 0.000 36 BasicObject#instance_eval 3.34 1.031 0.053 0.000 0.978 1 ActionView::CompiledTemplates#_app 2.98 0.047 0.047 0.000 0.000 6 <Class::Dir>#[] 2.52 0.042 0.040 0.001 0.001 74 <Module::ActiveSupport::Multibyte> 2.36 0.040 0.037 0.000 0.002 1095 Mustache::Parser#regexp 2.08 0.051 0.033 0.000 0.018 46 <Module::Marshal>#load 1.99 0.032 0.032 0.000 0.000 6 Kernel#require 1.98 0.032 0.032 0.000 0.000 2181 String#to_s 1.67 0.506 0.027 0.000 0.480 1007 *Array#each 1.55 0.050 0.025 0.000 0.025 972 Psych::ScalarScanner#tokenize 1.48 0.024 0.024 0.000 0.000 168 <Class::File>#exist? 1.35 0.068 0.021 0.000 0.046 663 Mustache::Parser#position 1.31 0.066 0.021 0.000 0.045 675 Mustache::Parser#scan_text  Method name   Time   Calls 
  13. 35.

    Profile of our code %self total self wait child calls

    name 5.41 0.271 0.086 0.000 0.185 675 Mustache::Parser#scan_tags 3.90 0.062 0.062 0.000 0.000 36 BasicObject#instance_eval 3.34 1.031 0.053 0.000 0.978 1 ActionView::CompiledTemplates#_app 2.98 0.047 0.047 0.000 0.000 6 <Class::Dir>#[] 2.52 0.042 0.040 0.001 0.001 74 <Module::ActiveSupport::Multibyte> 2.36 0.040 0.037 0.000 0.002 1095 Mustache::Parser#regexp 2.08 0.051 0.033 0.000 0.018 46 <Module::Marshal>#load 1.99 0.032 0.032 0.000 0.000 6 Kernel#require 1.98 0.032 0.032 0.000 0.000 2181 String#to_s 1.67 0.506 0.027 0.000 0.480 1007 *Array#each 1.55 0.050 0.025 0.000 0.025 972 Psych::ScalarScanner#tokenize 1.48 0.024 0.024 0.000 0.000 168 <Class::File>#exist? 1.35 0.068 0.021 0.000 0.046 663 Mustache::Parser#position 1.31 0.066 0.021 0.000 0.045 675 Mustache::Parser#scan_text
  14. 36.

    Before and after self calls name self calls name 0.051

    2 BasicObject#instance_eva 0.086 675 Mustache::Parser#scan_ta 0.042 6 <Class::Dir>#[] 0.062 36 BasicObject#instance_eva 0.014 110 Mustache::Parser#scan_ta 0.053 1 ActionView::CompiledTemp 0.014 337 *Array#each 0.047 6 <Class::Dir>#[] 0.004 145 Sprockets::Asset#depende 0.040 74 <Module::ActiveSupport:: 0.004 149 *Array#map 0.037 1095 Mustache::Parser#regexp 0.003 110 Mustache::Parser#scan_te 0.033 46 <Module::Marshal>#load 0.003 109 Mustache::Parser#positio 0.032 6 Kernel#require 0.003 110 Mustache::Parser#scan_un 0.032 2181 String#to_s 0.002 2 <Class::IO>#binread 0.027 1007 *Array#each 0.002 186 <Class::File>#exist? 0.025 972 Psych::ScalarScanner#tok 0.002 774 Kernel#is_a? 0.024 168 <Class::File>#exist? 0.002 186 Hike::Trail#stat 0.021 663 Mustache::Parser#positio 0.002 232 String#split 0.021 675 Mustache::Parser#scan_te
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