Source code for Benchmark: Deep directory structure vs. flat directory structure to store millions of files on ext4 article (https://medium.com/@hartator/benchmark-deep-directory-structure-vs-flat-directory-structure-to-store-millions-of-files-on-ext4-cac1000ca28)

benchmark-deep-vs-flat-directories.rb

require 'digest'
require 'benchmark'

hash = {}

10_000_000.times do
  key = Digest::MD5.hexdigest(rand.to_s)
  value = Digest::MD5.hexdigest(rand.to_s)
  hash[key] = value
end

FileUtils.mkdir_p "dir_flat"
FileUtils.mkdir_p "dir_deep"

puts Benchmark.measure {
  hash.each do |key,value|
    File.write "./dir_flat/#{key}", value
  end
}

puts Benchmark.measure {
  hash.each do |key,value|
    File.read "./dir_flat/#{key}"
  end
}

puts Benchmark.measure {
  hash.keys.each do |key|
    dir_path = "./dir_deep/#{key[0..1]}/#{key[2..3]}/"
    FileUtils.mkdir_p dir_path
  end
}

puts Benchmark.measure {
  hash.each do |key,value|
    dir_path = "./dir_deep/#{key[0..1]}/#{key[2..3]}/"
    File.write dir_path + key, value
  end
}

puts Benchmark.measure {
  hash.each do |key,value|
    dir_path = "./dir_deep/#{key[0..1]}/#{key[2..3]}/"
    File.read dir_path + key 
  end
}