md5_benchmark.rb

# Performance benchmark of native Ruby MD5 digest vs. shelling out
# to openssl md5 utility.  Benchmark clearly shows shelling out is 
# massively slower, as you might expect.
#
# [master ~/src/cloudfront_asset_host]$> ruby md5_benchmark.rb 
# Openssl:   0.110000   0.650000   5.220000 (  7.547728)
# Native:   0.020000   0.010000   0.030000 (  0.031182)

require 'benchmark'
require 'digest/md5'

def open_md5(path)
  `openssl md5 #{path}`.split(/\s/)[1].to_s
end

def native_md5(path)
  Digest::MD5.hexdigest(File.read(path))
end

# Warm it up
10.times { open_md5(__FILE__) }
10.times { native_md5(__FILE__) }

measure = Benchmark.measure { 1000.times { open_md5(__FILE__) } }
puts "Openssl: #{measure}"
measure = Benchmark.measure { 1000.times { native_md5(__FILE__) } }
puts "Native: #{measure}"