benchmark array membership in REE 1.8.7 2010-04-19 patchlevel 253 - 2010.02

benchmark_array_membership.rb

# benchmark array membership in REE 1.8.7 2010-04-19 patchlevel 253 - 2010.02
# the basic access-pattern is like Array#include? - a big array and to check if a a smaller/single-object
# is included in the bigger one

# TODO: why is such a big difference between the two - irrespecive of the fact that both of them trying to do diff things
# array_intersect is checking if an array containing a single element is included? in a bigger array
# arr_ele_include is checking if an single integer array is included? in a bigger array

# array_intersect is the fastest followed by arr_ele_include

# ruby -v
# ruby 1.8.7 (2010-04-19 patchlevel 253) [x86_64-linux], MBARI 0x6770, Ruby Enterprise Edition 2010.02

require 'benchmark'
require 'set'

ARR = (1..5000).to_a
ELE_ARR = [3301]
ELE = 3301

ARR_SET = ARR.to_set
ELE_SET = ELE_ARR.to_set

SO_MUCH = 10_000

Benchmark.bmbm { |x|
  x.report("arr_include") {
    SO_MUCH.times { ARR.include?(ELE_ARR) } 
  }
  x.report("array_intersect") {
    SO_MUCH.times { !(ARR && ELE_ARR).empty? }
  }
  x.report("arr_ele_include") {
    SO_MUCH.times { ARR.include?(ELE) } 
  }
  x.report("set_include") {
    SO_MUCH.times { ARR_SET.include?(ELE_SET) } 
  }
  x.report("set_intersect") {
    SO_MUCH.times { ARR_SET.subset?(ELE_SET) }
  }
}

__END__

# ruby 1.8.7 (2010-04-19 patchlevel 253) [x86_64-linux], MBARI 0x6770, Ruby Enterprise Edition 2010.02
Rehearsal ---------------------------------------------------
arr_include      16.370000   0.020000  16.390000 ( 16.525376)
array_intersect   0.000000   0.000000   0.000000 (  0.002414)
arr_ele_include   2.070000   0.000000   2.070000 (  2.071033)
set_include       0.020000   0.000000   0.020000 (  0.015478)
set_intersect     0.010000   0.000000   0.010000 (  0.012009)
----------------------------------------- total: 18.490000sec

                      user     system      total        real
arr_include      16.330000   0.080000  16.410000 ( 16.474641)
array_intersect   0.000000   0.000000   0.000000 (  0.002331)
arr_ele_include   2.080000   0.000000   2.080000 (  2.099532)
set_include       0.020000   0.000000   0.020000 (  0.015422)
set_intersect     0.010000   0.000000   0.010000 (  0.012076)

#ruby 1.9.2p0 (2010-08-18 revision 29036) [x86_64-linux]
Rehearsal ---------------------------------------------------
arr_include      11.910000   0.000000  11.910000 ( 11.922087)
array_intersect   0.000000   0.000000   0.000000 (  0.001565)
arr_ele_include   1.880000   0.000000   1.880000 (  1.906705)
set_include       0.010000   0.000000   0.010000 (  0.014681)
set_intersect     0.000000   0.000000   0.000000 (  0.004333)
----------------------------------------- total: 13.800000sec

                      user     system      total        real
arr_include      11.880000   0.070000  11.950000 ( 11.997317)
array_intersect   0.000000   0.000000   0.000000 (  0.001642)
arr_ele_include   1.890000   0.000000   1.890000 (  1.899360)
set_include       0.010000   0.000000   0.010000 (  0.016123)
set_intersect     0.000000   0.000000   0.000000 (  0.004484)