Benchmark of JSON rendering in Ruby

benchamark_hash_to_json.rb

# gem install multi_json json yajl-ruby oj benchmark-memory

require 'multi_json'
require 'json'
require 'yajl'
require 'oj'
require 'benchmark'
require 'benchmark-memory'

hash1 = {
  'key1' => 'string',   # String
  'key2' => 153,        # Integer
  'key3' => 224.81,     # Float
  'key4' => true,       # Boolean
  'key5' => nil,        # Null
  'key6' => Date.today, # Date
  'key7' => Time.now,   # Datetime
}

hash2 = hash1.merge({
  'key8'  => {                             # 3-level tree
    'key8.1' => hash1.clone,
    'key8.2' => {
      'key8.2.1' => hash1.clone,
      'key8.2.2' => hash1.clone
    }
  },
  'key9'  => 10.times.map { hash1.clone }, # Array of Hashes
  'key10' => 'a'*100_000,                # 100KB file
})

hash3 = Hash[1_000.times.map do |i|
  key = "key#{i+1}"
  value = if i % 2 == 0
    hash1.clone
  else
    [hash1.clone, {'1' => {'2' => {'3' => {'4' => {'5' => {'6' => {'7' => hash2.clone}}}}}}}]
  end
  [key, value]
end]

[hash1, hash2, hash3].each_with_index do |hash_i, i|
  puts
  puts '------------------'
  puts "Benchmark of hash#{i+1}"
  puts '------------------'

  nrep = 100
  bench = Benchmark.bm(10) do |x|
    MultiJson.use :json_gem
    x.report('json_gem:')  { nrep.times { MultiJson.dump(hash_i) } }

    MultiJson.use :yajl
    x.report('yajl:')  { nrep.times { MultiJson.dump(hash_i) } }

    MultiJson.use :oj
    x.report('oj:')  { nrep.times { MultiJson.dump(hash_i) } }

    x.report('to_json:')  { nrep.times { hash_i.to_json } }
  end

  puts
  puts "Results in ms per execution:"
  bench.each do |bm|
    puts ">>>>> #{bm.label} - %.3f ms" % (bm.real*1000.0/nrep)
  end
  puts


  # https://github.com/michaelherold/benchmark-memory
  Benchmark.memory do |x|
    MultiJson.use :json_gem
    x.report('json_gem:')  { MultiJson.dump(hash_i) }

    MultiJson.use :yajl
    x.report('yajl:')  { MultiJson.dump(hash_i) }

    MultiJson.use :oj
    x.report('oj:')  { MultiJson.dump(hash_i) }

    x.report('to_json:')  { hash_i.to_json }

    x.compare!
  end
end

benchamark_json_render.rb

# gem install multi_json oj benchmark-memory rabl jbuilder

require 'multi_json'
require 'oj'
require 'rabl'
require 'jbuilder'
require 'benchmark'
require 'benchmark-memory'

class BaseModel
  def initialize(attrs={})
    attrs.each { |k, v| self.send("#{k}=", v) }
  end
end
class UserModel < BaseModel
  attr_accessor :name, :age, :email
end
class CommentModel < BaseModel
  attr_accessor :user, :message, :created_at, :attachment
end
class PostModel < BaseModel
  attr_accessor :content, :author, :comments, :created_at, :published
end

def create_post(size=1_000, comments=10, attachment_size=0)
  PostModel.new(
    content: '-'*size,
    author: UserModel.new(name: 'First Last', age: rand(100), email: 'user@email.com'),
    created_at: Time.now,
    published: true,
    comments: comments.times.map do
      CommentModel.new(
        user: UserModel.new(name: 'First Last', age: rand(100), email: 'user@email.com'),
        message: '-'*400,
        created_at: Time.now,
        attachment: '-'*attachment_size
      )
    end
  )
end

def render_jbuilder(post)
  Jbuilder.encode do |json|
    json.content post.content
    json.created_at post.created_at
    json.published post.published
    json.author do
      json.name post.author.name
      json.age post.author.age
      json.email post.author.email
    end
    json.comments post.comments do |comment|
      json.created_at comment.created_at
      json.message comment.message
      json.user do
        json.name comment.user.name
        json.age comment.user.age
        json.email comment.user.email
      end
      json.attachment comment.attachment
    end
  end
end

def render_rabl(post)
  # # Create a post.rabl file with the following content
  # attribute :content
  # attribute :created_at
  # attribute :published

  # child(:author) do
  #   attribute :name
  #   attribute :age
  #   attribute :email
  # end

  # child(:comments) do
  #   attribute :created_at
  #   attribute :message
  #   child(:user) do
  #     attribute :name
  #     attribute :age
  #     attribute :email
  #   end
  #   attribute :attachment
  # end
  Rabl.render(post, 'post', view_path: '.', format: :json)
end

def render_dump(post)
  MultiJson.dump({
    'content'     => post.content,
    'created_at'  => post.created_at,
    'published'   => post.published,

    'author'      => {
      'name'  => post.author.name,
      'age'   => post.author.age,
      'email' => post.author.email,
    },

    'comments'    => post.comments.map do |comment|
      {
        'created_at' => comment.created_at,
        'message'    => comment.message,
        'user'       => {
          'name'  => comment.user.name,
          'age'   => comment.user.age,
          'email' => comment.user.email,
        },
        'attachment' => comment.attachment,
      }
    end
  })
end

def render_string(post)
%({
  "content": #{MultiJson.encode(post.content)},
  "created_at": #{MultiJson.encode(post.created_at)},
  "published": #{MultiJson.encode(post.published)},
  "author":{
    "name": #{MultiJson.encode(post.author.name)},
    "age": #{MultiJson.encode(post.author.age)},
    "email": #{MultiJson.encode(post.author.email)}
  },
  "comments":[
  #{
    post.comments.map do |comment|
      %({
        "created_at": #{MultiJson.encode(comment.created_at)},
        "message": #{MultiJson.encode(comment.message)},
        "user":{
          "name": #{MultiJson.encode(comment.user.name)},
          "age": #{MultiJson.encode(comment.user.age)},
          "email": #{MultiJson.encode(comment.user.email)}
        },
        "attachment": #{MultiJson.encode(comment.attachment)}
      })
    end.join(",\n")
  }
  ]
})
end

# Confirm render_string is working fine
# MultiJson.load(render_string(post_i)) == MultiJson.load(render_dump(post_i))

post1 = create_post(1_000, 10, 0)
post2 = create_post(1_000_000, 200, 1_000)
post3 = create_post(10_000_000, 5_000, 10_000)

MultiJson.use :oj

[post1, post2, post3].each_with_index do |post_i, i|
  puts
  puts '------------------'
  puts "Benchmark of post#{i+1}"
  puts '------------------'

  nrep = 1000
  bench = Benchmark.bm(10) do |x|
    x.report('rabl:')  { nrep.times { render_rabl(post_i) } }
    x.report('jbuilder:')  { nrep.times { render_jbuilder(post_i) } }
    x.report('dump:')  { nrep.times { render_dump(post_i) } }
    x.report('string:')  { nrep.times { render_string(post_i) } }
  end

  puts
  puts "Results in ms per execution:"
  bench.each do |bm|
    puts ">>>>> #{bm.label} - %.3f ms" % (bm.real*1000.0/nrep)
  end
  puts

  # https://github.com/michaelherold/benchmark-memory
  Benchmark.memory do |x|
    x.report('rabl:')  { render_rabl(post_i) }
    x.report('jbuilder:')  { render_jbuilder(post_i) }
    x.report('dump:')  { render_dump(post_i) }
    x.report('string:')  { render_string(post_i) }
    x.compare!
  end
end