base62_benchmark.rb

require "all_your_base"
require "benchmark/ips"
require "minitest/autorun"
require "securerandom"

BASE62_CHARS = [
  "0", "1", "2", "3", "4", "5", "6", "7", "8", "9", 
  "a", "b", "c", "d", "e", "f", "g", "h", "i", "j", "k", "l", "m", "n", "o",
  "p", "q", "r", "s", "t", "u", "v", "w", "x", "y", "z", "A", "B", "C", "D", 
  "E", "F", "G", "H", "I", "J", "K", "L", "M", "N", "O", "P", "Q", "R", "S", 
  "T", "U", "V", "W", "X", "Y", "Z"
]

def old_impl
  o = [('0'..'9'), ('a'..'z'), ('A'..'Z')].map { |i| i.to_a }.flatten
  (0...22).map { o[SecureRandom.random_number(o.length)] }.join
end

def new_impl
  bytes = SecureRandom.random_bytes(22)

  "".tap do |str|
    bytes.each_byte.each { |b| str << BASE62_CHARS[b.to_i % 62] }
  end
end

def all_your_base
  uuid = SecureRandom.uuid.gsub(/\-/, '').to_i(16)
  AllYourBase::Are.convert_from_base_10(uuid, radix: 62)
end

# benchmarks
Benchmark.ips do |x|
  x.report("old impl") do
    old_impl
  end

  x.report("all your base") do
    all_your_base
  end

  x.report("new impl") do
    new_impl
  end

  x.compare!
end

# tests
class TestBase62 < MiniTest::Unit::TestCase
  def test_the_new_impl_uuid_size_is_always_22
    100_000.times do
      uuid = new_impl
      assert_equal 22, uuid.size
    end
  end

  def test_the_new_impl_uuid_size_is_unique
    uuids = 100_000.times.map { new_impl }
    
    assert_equal 100_000, uuids.size
    assert_equal 100_000, uuids.uniq.size
  end

  def test_the_old_impl_uuid_size_is_always_22
    100_000.times do
      uuid = old_impl
      assert_equal 22, uuid.size
    end
  end

  def test_the_all_your_base_uuid_size_is_always_22
    100_000.times do
      uuid = all_your_base
      assert_equal 22, uuid.size
    end
  end
end

results.txt

% ruby base62_benchmark.rb
Calculating -------------------------------------
            old impl     1.012k i/100ms
       all your base     3.280k i/100ms
            new impl    13.918k i/100ms
-------------------------------------------------
            old impl     10.192k (± 6.0%) i/s -     51.612k
       all your base     33.896k (± 4.8%) i/s -    170.560k
            new impl    167.665k (± 4.8%) i/s -    848.998k

Comparison:
            new impl:   167665.2 i/s
       all your base:    33895.9 i/s - 4.95x slower
            old impl:    10191.9 i/s - 16.45x slower

Run options: --seed 19017

# Running tests:

...F

Finished tests in 11.605460s, 0.3447 tests/s, 17233.6125 assertions/s.

  1) Failure:
test_the_all_your_base_uuid_size_is_always_22(TestBase62) [foo.rb:77]:
Expected: 22
  Actual: 21

4 tests, 200004 assertions, 1 failures, 0 errors, 0 skips