digest-sha256-file-vs-system-sha256sum.rb

mk@… ~/Projects/Sandbox % cat digest-sha256-file-vs-system-sha256sum.rb 
#!/usr/bin/env ruby

require 'tempfile'
require 'digest/sha2'

require 'benchmark/ips'

file = Tempfile.new 'testfile'
file.write 'a' * 1024 * 1024 * 2

Benchmark.ips do |x|
  x.report 'Digest::SHA256.file' do
    Digest::SHA256.file(file.path).hexdigest
  end

  x.report '`sha256sum`' do
    `sha256sum #{file.path}`.strip
  end
end

file.close
file.unlink
# mk@… ~/Projects/Sandbox % ruby digest-sha256-file-vs-system-sha256sum.rb 
# Warming up --------------------------------------
#  Digest::SHA256.file    72.000  i/100ms
#          `sha256sum`    44.000  i/100ms
# Calculating -------------------------------------
#  Digest::SHA256.file    738.569  (± 2.0%) i/s -      3.744k in   5.071405s
#          `sha256sum`    457.612  (± 7.9%) i/s -      2.288k in   5.034049s
# ruby digest-sha256-file-vs-system-sha256sum.rb  10,21s user 4,17s system 99% cpu 14,393 total