shell vs code

bundler_gem_bench.rb

require "tempfile"
require "bundler/cli"
require 'benchmark'

def run
  $stdout = StringIO.new;
  10.times do
    Dir.mktmpdir do |dir|
      yield(dir)
    end
  end

  $stdout = STDOUT
end

Benchmark.bm do |x|
  x.report("shell") do
    run do |dir|
      system "bundle gem rails-assets-moment > /dev/null", :chdir => dir
    end
  end

  x.report("code ") do
    run do |dir|
      pid = fork do
        Dir.chdir(dir) do
          Bundler::CLI.start(["gem", "rails-assets-moment"])
        end
      end
      Process.wait(pid)
    end
  end
end

# λ ruby bundler_bench.rb
#        user     system      total        real
# shell  0.020000   0.030000   7.390000 (  7.455510)
# code   0.020000   0.050000   0.730000 (  0.758425)