test merge! on hstore

bench_merge.rb

class BenchMerge

  # class CreateAnimals < ActiveRecord::Migration
  #   def change
  #     enable_extension 'hstore'
  #
  #
  #     create_table :animals do |t|
  #       t.hstore :data
  #       t.timestamps null: false
  #     end
  #   end
  # end


  def self.perf

    h = (1..26).map{|i| [(96+i).chr.to_sym, rand(100.0)]}.to_h

    Benchmark.bm do |x|

      x.report(:merge) do
        animal = Animal.new(data:{})
        3000.times do
          animal.data = animal.data.merge h
        end
      end

      x.report(:merge!) do
        animal = Animal.new(data:{})
        3000.times do
          animal.data.merge! h
        end
      end

    end
    
    #        user     system      total        real
    # merge  3.640000   0.020000   3.660000 (  3.728977)
    # merge!  0.000000   0.000000   0.000000 (  0.005567)


  end

  def self.dirty
    h = {a:"1", b:"2"}

    puts "1. merge"

    animal = Animal.create!(data: h)
    animal.data = animal.data.merge h
    puts animal.changed? ? "changed" : "not changed"
    puts animal.changes.inspect

    puts "2. merge!"
    animal = Animal.create!(data: h)
    animal.data.merge! h
    puts animal.changed? ? "changed" : "not changed"
    puts animal.changes.inspect

    # 1. merge
    # not changed
    # {}
    # 2. merge!
    # changed
    # {"data"=>[{"a"=>"1", "b"=>"2"}, {"a"=>"1", "b"=>"2"}]}

  end

end