benchmark_env.rb

#https://gist.github.com/709860

require 'benchmark'

# does Benchmark::bmbm have environments/setup like Test::Unit
# want some variables to be set per benchmark case - now have to dup them myself
# is is needed as the testcases have destructive operations, otherwise the testcases will be dependent on each other

def benchmark_setup(obj=TOP_SELF)
  code = <<-CODE
    big = (1..95).to_a
    sml = (75..110).to_a
  CODE

  # passing code in lambda does not modify but string does
  # obj.instance_eval {
  #   big = (1..95).to_a
  #   sml = (75..110).to_a
  # }
  obj.instance_eval(code, __FILE__, __LINE__)
end

TOP_SELF = self

module Benchmark
  alias_method :org_measure, :measure
  def measure(label="", &blk)
    benchmark_setup(TOP_SELF)
    org_measure(label, &blk)
  end

  module_function :org_measure
end

Benchmark.bmbm { |x|
  x.report("iterate_larger") {
    #big = big_arr.dup
    #sml = sml_arr.dup
    
    big.each do |r|
      sml.delete_if {|s| s == r }
    end
  }
}
Benchmark.bmbm { |x|
  x.report("set_diff") {
    #big = big_arr.dup
    #sml = sml_arr.dup
    sml - big 
  }
}
Benchmark.bmbm { |x|
  x.report("iterate_smaller") {
    #big = big_arr.dup
    #sml = sml_arr.dup
    sml.collect do |s|
      s unless big.include?(x)
    end.compact
  }
}