Check gems memory consumption and load time

memory_consumption.rb

require 'benchmark'

def require_and_profile(gemname = nil)
  unless gemname
    puts "%-20s: %10s | %10s | %10s" % ['gem','increment','total','time']
    return
  end
  
  # checked on procps-ng (ps) version 3.3.3 and 3.3.9
  memory_usage = `ps -o rss= -p #{Process.pid}`.to_i / 1024.0
  load_time = Benchmark.realtime { require gemname }
  puts "%-20s: %10.2f | %10.2f | %10.2f" % [ gemname, (`ps -o rss= -p #{Process.pid}`.to_i / 1024.0 - memory_usage), (`ps -o rss= -p #{Process.pid}`.to_i / 1024.0), load_time.round(2)]
end

pattern = /^[^#]*gem[ ]*['"]([^,'"]*)['"][ ,~>0-9\.'"]*(:require[ => ]*['"]([^'"]*)['"][, ])?/

require_and_profile
File.open('Gemfile').each do |line|
  if line.match(pattern)
    if line.match(pattern)[3]
      require_and_profile line.match(pattern)[3]
    else
      require_and_profile line.match(pattern)[1]
    end
  end
end