preliminary benchmarks for json on MacRuby

bench.rb

require 'rubygems'
gem 'minitest', '>= 2.3.1'
require 'minitest/autorun'
require 'minitest/benchmark'
require 'json'
framework 'Foundation'

class Bench < MiniTest::Unit::TestCase
  def self.order
    :alpha
  end

  def self.bench_range
    bench_exp 1_000, 100_000
  end

  def json val
    assert_performance_linear do |n|
      n.times { val.to_json }
    end
  end

  # @todo varying lengths of strings, not important now because it does
  #       not stress the part of the code that is responsible for the
  #       slow down
  def bench_string
    json ['blah']
  end

  def bench_nsstring
    json [NSString.stringWithString('blah')]
  end

  def bench_number
    json [100]
  end

  def bench_hash
    # hash = { this:{is:{a:{test:{}}}}, life:{universe:42}, pie:'cake', hash:{with:1,few:2,keys:3} }
    json a: {}, b: {}
  end

  def bench_nsdict
    x = NSDictionary
    def NSDictionary.y *args
      dictionaryWithObjectsAndKeys *args.reverse, nil
    end
    # hash = x.y('this', x.y('a', x.y('test', x.y())), 'life', x.y('universe',42), 'pie', 'cake', 'hash', x.y('with',1,'few',2,'keys',3))
    json x.y('a',x.y, 'b',x.y)
  end

  def bench_array
    # array = [[[[[[]]]]], [[]], [[[[],[]],[[],[],[]],[]]], [[],[]], [[[],[]]]]
    json [[1],[2]]
  end

  def bench_nsarray
    x = NSArray
    def x.y *args
      arrayWithObjects *args, nil
    end
    # array = x.y x.y(x.y(x.y(x.y(x.y())))), x.y(x.y), x.y(x.y(x.y(x.y,x.y),x.y(x.y,x.y,x.y), x.y)), x.y(x.y,x.y), x.y(x.y(x.y,x.y))
    json x.y(x.y(1), x.y(2))
  end

  def bench_nil
    json [nil]
  end

  def bench_boolean
    json [true, false]
  end

  def bench_bignum
    json [1_000_000_000_000_000_000_000_000_000_000_000_000_000]
  end

  def bench_float
    json [2.71828183]
  end

  def bench_object
    json [Object.new]
  end

  def bench_smorgasbord
    json can: [{you: 'take', me: 'to', funky: 'town?'}, 1, 2, 3000, Object.new, true, -3.1415, nil]
  end
end

This is from applying appropriate patches to the upstream JSON repository:

Bench   1000    10000   100000
bench_array      0.009178    0.068889    0.576111
bench_nsarray    0.006231    0.071549    0.659718
bench_bignum     0.013563    0.143416    1.418103
bench_boolean    0.005108    0.065971    0.591222
bench_float      0.008823    0.121051    1.025400
bench_hash       0.032613    0.262340    2.698372
bench_nsdict     0.067821    0.338544    3.332269
bench_nil        0.005587    0.066914    0.592831
bench_number     0.005283    0.068908    0.547478
bench_object     0.042540    0.205396    2.025258
bench_smorgasbord    0.077420    0.754987    7.198482
bench_string     0.013055    0.124828    1.179611
bench_nsstring   0.013120    0.150757    1.456123

Finished benchmarks in 26.300107s, 0.4943 tests/s, 0.4943 assertions/s.