benchmark for json, yajl and oj.

bench

~ ruby json_benchmark.rb
String to JSON
Warming up --------------------------------------
             Oj.dump    24.918k i/100ms
           Yajl.dump     9.461k i/100ms
           JSON.dump    24.797k i/100ms
    MessagePack.dump    44.355k i/100ms
Calculating -------------------------------------
             Oj.dump    267.683k (± 3.4%) i/s -      1.346M in   5.032971s
           Yajl.dump     98.929k (± 2.8%) i/s -    501.433k in   5.072850s
           JSON.dump    267.699k (± 3.4%) i/s -      1.339M in   5.008431s
    MessagePack.dump    506.836k (± 3.1%) i/s -      2.573M in   5.080857s

Comparison:
    MessagePack.dump:   506835.6 i/s
           JSON.dump:   267699.2 i/s - 1.89x  slower
             Oj.dump:   267683.0 i/s - 1.89x  slower
           Yajl.dump:    98928.5 i/s - 5.12x  slower

JSON to String
Warming up --------------------------------------
             Oj.load     6.843k i/100ms
           Yajl.load     4.075k i/100ms
          JSON.parse     4.739k i/100ms
    MessagePack.load     9.835k i/100ms
Calculating -------------------------------------
             Oj.load     71.835k (± 2.6%) i/s -    362.679k in   5.052311s
           Yajl.load     41.681k (± 2.5%) i/s -    211.900k in   5.087144s
          JSON.parse     46.690k (± 4.9%) i/s -    236.950k in   5.087611s
    MessagePack.load    100.421k (± 4.5%) i/s -    501.585k in   5.005654s

Comparison:
    MessagePack.load:   100420.7 i/s
             Oj.load:    71835.4 i/s - 1.40x  slower
          JSON.parse:    46690.3 i/s - 2.15x  slower
           Yajl.load:    41681.5 i/s - 2.41x  slower

ruby_benchmark.rb

require 'benchmark/ips'
require 'json'
require 'oj'
require 'yajl'
require 'msgpack'

HASH = {"audios_count"=>0, "audios_updated_at"=>nil, "avatar_content_type"=>nil, "avatar_file_name"=>nil, "avatar_file_size"=>nil, "avatar_updated_at"=>nil, "backend_id"=>nil, "cached_average_listen_span"=>0.0, "cached_followers_count"=>1, "cached_followings_count"=>1, "cached_likes_count"=>1, "city"=>nil, "country_code"=>nil, "country_name"=>nil, "cover_content_type"=>nil, "cover_file_name"=>nil, "cover_file_size"=>nil, "cover_updated_at"=>nil, "created_at"=>"Thu, 17 Jan 2013 08:49:20 UTC +00:00", "description"=>nil, "email"=>"test@gmail.com", "followers_updated_at"=>"Thu, 23 May 2013 09:19:19 UTC +00:00", "followings_updated_at"=>nil, "id"=>2, "links"=>nil, "loves_updated_at"=>"Wed, 15 May 2013 16:20:40 UTC +00:00", "name"=>"Liu Fengyun", "playlists_count"=>1, "playlists_updated_at"=>nil, "provider"=>"facebook", "role"=>nil, "slug"=>"liu-fengyun", "source"=>nil, "source_id"=>nil, "state_code"=>nil, "uid"=>"11111111", "unread_notifications_count"=>5, "updated_at"=>"Fri, 24 May 2013 07:32:16 UTC +00:00", :avatar=>{:large=>"//graph.facebook.com/11111111/picture?type=large", :normal=>"//graph.facebook.com/11111111/picture?type=normal", :small=>"//graph.facebook.com/11111111/picture?type=small"}, :slug=>"liu-fengyun", :cover=>"/covers/original/missing.png"}

puts 'String to JSON'
Benchmark.ips do |x|
  hash = HASH

  x.report('Oj.dump') { Oj.dump hash }
  x.report('Yajl.dump') { Yajl.dump hash }
  x.report('JSON.dump') { Oj.dump hash }
  x.report('MessagePack.dump') { MessagePack.dump hash }

  x.compare!
end

puts 'JSON to String'
Benchmark.ips do |x|
  json = HASH.to_json
  msgpack = HASH.to_msgpack

  x.report('Oj.load') { Oj.load json }
  x.report('Yajl.load') { Yajl.load json }
  x.report('JSON.parse') { JSON.parse json }
  x.report('MessagePack.load') { MessagePack.load msgpack }

  x.compare!
end