bench.rb

# Compare performance of pack/unpack versus JSON generate/parse
#

require 'rubygems'
require 'benchmark'
require 'json'

A = (0..1_000).to_a

org_array = []
json_array = []
packed_array = []

0.upto(100_000) do |i|
  org_array << A
end


def pack_it(array)
  array.pack('N*')
end

def unpack_it(string)
  string.unpack('N*')
end

org_array.each { |array| json_array << JSON.fast_generate(array) }
org_array.each { |array| packed_array << pack_it(array) }

Benchmark.bmbm("JSON versus pack/unpack".size) do |x|
  x.report("fast generate:") do
    org_array.each { |array|  JSON.fast_generate(array) }
  end

  x.report("pack:") do
    org_array.each { |array|  pack_it(array) }
  end


  x.report("parse:") do
    json_array.each { |string|  JSON.parse(string) }
  end

  x.report("unpack:") do
    packed_array.each { |string|  unpack_it(string) }
  end
end

output.txt

Chuck-Remess-Mac-Pro:pack_vs_json cremes$ ruby -v
jruby 1.6.3 (ruby-1.8.7-p330) (2011-07-07 965162f) (Java HotSpot(TM) 64-Bit Server VM 1.6.0_26) [darwin-x86_64-java]
Chuck-Remess-Mac-Pro:pack_vs_json cremes$ ruby --server -J-Xmx3g bench.rb 
Rehearsal ----------------------------------------------------------
fast generate:          27.855000   0.000000  27.855000 ( 27.855000)
pack:                    3.114000   0.000000   3.114000 (  3.114000)
parse:                  62.146000   0.000000  62.146000 ( 62.147000)
unpack:                  3.233000   0.000000   3.233000 (  3.233000)
------------------------------------------------ total: 96.348000sec

                             user     system      total        real
fast generate:          27.390000   0.000000  27.390000 ( 27.390000)
pack:                    3.105000   0.000000   3.105000 (  3.105000)
parse:                  61.729000   0.000000  61.729000 ( 61.729000)
unpack:                  3.337000   0.000000   3.337000 (  3.336000)
Chuck-Remess-Mac-Pro:pack_vs_json cremes$ rvm default
Chuck-Remess-Mac-Pro:pack_vs_json cremes$ ruby -v
ruby 1.9.2p136 (2010-12-25 revision 30365) [x86_64-darwin10.5.0]
Chuck-Remess-Mac-Pro:pack_vs_json cremes$ ruby bench.rb 
Rehearsal ----------------------------------------------------------
fast generate:          12.740000   0.080000  12.820000 ( 12.819956)
pack:                    5.870000   0.030000   5.900000 (  5.893181)
parse:                  24.960000   0.040000  25.000000 ( 25.026834)
unpack:                 10.650000   0.010000  10.660000 ( 10.653586)
------------------------------------------------ total: 54.380000sec

                             user     system      total        real
fast generate:          13.130000   0.050000  13.180000 ( 13.190665)
pack:                    6.120000   0.010000   6.130000 (  6.138026)
parse:                  24.910000   0.050000  24.960000 ( 25.111740)
unpack:                 10.840000   0.030000  10.870000 ( 10.913505)
Chuck-Remess-Mac-Pro:pack_vs_json cremes$