CanCanCan performance scripts

performance-growth.rb

require 'bundler'
require 'csv'
Bundler.setup
require 'cancan'

NUM_SUBJECTS = 1..100

# returns µs
def time &block
  before = Time.now.to_r
  yield
  difference = Time.now.to_r - before
  (difference * 10**6).to_i
end

results = NUM_SUBJECTS.map do |num_subjects|
  subjects = (1..num_subjects).map { Class.new }
  rules = %i[read update manage destroy].product(subjects)
  ability = Class.new do
    include CanCan::Ability

    define_method(:initialize) do
      rules.each do |action, subject|
        can action, subject
      end
    end
  end.new

  timings = []
  3.times do
    rules.each do |action, subject|
      timing = time { ability.can?(action, subject) }
      timings << timing
    end
  end

  timings.sort!
  mean = timings.reduce(:+) / timings.size.to_f
  ninty = timings[timings.size * 0.9]
  [num_subjects, mean, ninty]
end

id = `git rev-parse head`.strip
CSV.open("rule-lookup-timing-#{id}.csv", 'w') do |csv|
  csv << %w[num-subjects mean 90%]
  results.each do |result|
    csv << result
  end
end

performance-single.rb

require 'bundler'
Bundler.setup
require 'cancan'

ITERATIONS = 8
NUM_SUBJECTS = 100

# returns nanoseconds
def time &block
  before = Time.now.to_r
  yield
  difference = Time.now.to_r - before
  (difference * 10**6).to_i
end

subjects = (1..NUM_SUBJECTS).map { Class.new }
rules = %i[read update manage destroy].product(subjects)
ability = Class.new do
  include CanCan::Ability

  define_method(:initialize) do
    rules.each do |action, subject|
      can action, subject
    end
  end
end.new

timings = []
ITERATIONS.times do
  rules.each do |action, subject|
    timing = time { ability.can?(action, subject) }
    timings << timing
  end
end

id = `git rev-parse head`.strip
File.write("rule-lookup-timing--#{id}.csv", timings.join("\n"))