Remove pry, don't need it

gsub_benchmark.rb

#!/usr/bin/env ruby
# frozen_string_literal: true
#
# This script demonstrates a performance regression introduced in https://github.com/rails/rails/pull/34405
# That PR patched ActiveSupport::SafeBuffer methods gsub, gsub!, sub and sub! to set backreferences, but
# in doing so incurred a significant penalty.
# 
# This script creates a random string with texts at random locations which are swapped with gsub. The string
# is random but seeded the same each run, so the same length produces the same string.
# 
# Run without the -a option to test performance with Ruby's String class.
# Run with -a and an activesupport version to test performance with any version of ActiveSupport
#
# e.g.
#
# ruby gsub_benchmark.rb -i 10000
# ruby gsub_benchmark.rb -i 10000 -a 6.0.3.2
# ruby gsub_benchmark.rb -i 10000 -a 5.2

require 'optparse'

NUM_ITERATIONS = 10_000
LENGTH=100_000
NUM_MATCHES = 100

options = {
  iterations: NUM_ITERATIONS,
  length: LENGTH,
  matches: NUM_MATCHES,
  active_support_version: nil
}

parser = OptionParser.new do |opts|
  opts.banner = "USAGE: measure_swaptime [options]"

  opts.on("-i", "--iterations [NUM]", Integer, "Number of iterations (Default: #{NUM_ITERATIONS})") do |v|
    options[:iterations] = v
  end

  opts.on("-l", "--length [LENGTH]", Integer, "Length of string (Default: #{LENGTH})") do |v|
    options[:length] = v
  end

  opts.on("-m", "--matches [NUM]", Integer, "Number of matches in string (Default: #{NUM_MATCHES})") do |v|
    options[:matches] = v
  end

  opts.on("-a", "--active-support [VERSION]", String, "Set ActiveSupport version (Default: ActiveSupport is *not* required)") do |v|
    options[:active_support_version] = v
  end
end

parser.parse!

require 'bundler/inline'

gemfile do
  source "https://rubygems.org"
  gem 'activesupport', options[:active_support_version], require: 'active_support' if options[:active_support_version]
end

str_class = options[:active_support_version] ? ActiveSupport::SafeBuffer : String
str = str_class.new

puts "String Class: #{str_class.name}"
if options[:active_support_version]
  puts "ActiveSupport version: #{options[:active_support_version]}." 
else
  puts "ActiveSupport is not loaded."
end

srand(0) # set seed to ensure we always get the same string
while str.length < options[:length]
  str << rand(36**1024).to_s(36) + "\n"
end

matcher = /foo/
source = 'foo'
target = 'bar'

options[:matches].times do
  str.insert(rand(str.length), source)
end

require 'benchmark'

GC.start

durations = []

options[:iterations].times do |i|
  duped = str.dup
  # ensure GC plays no role by force-triggering it every 100 iterations
  GC.start if i % 100 == 0

  result = Benchmark.measure do
    duped = duped.gsub(matcher) do
      target
    end
    raise(Exception, "No swaps performed") if !(duped =~ /#{target}/)
  end
  durations << result.utime
end

puts "Max: #{durations.max*1000} ms"
puts "Min: #{durations.min*1000} ms"
puts "Average: #{durations.sum / durations.size * 1000} ms"
puts "Median: #{durations.sort[durations.length / 2] * 1000} ms"