benchmark_json_parse_into_objects

# frozen_string_literal: true
require 'benchmark'

namespace :benchmark do
  desc 'Benchmark Hash vs Openstruct vs Struct for a smallish data structure'
  task openstruct: :environment do

    CYCLES = 1_000
    PRINT_EVERY = 50
    DATA = {
      a: 'foo',
      b: 'bar',
      c: 'baz',
      d: 'weed',
      e: 'thc'
    }.freeze

    Benchmark.bm do |x|

      puts 'Hash'
      x.report do
        CYCLES.times do |i|
          obj = JSON.parse(json, symbolize_names: true)
          member = DATA.keys.sample
          "Value at #{i} for #{member}: #{obj[member]}"
        end
      end

      puts 'OpenStruct'
      x.report do
        CYCLES.times do |i|
          obj = JSON.parse(json, object_class: OpenStruct)
          member = DATA.keys.sample
          "Value at #{i} for #{member}: #{obj.send(member)}"
        end
      end

      puts 'Struct'
      x.report do
        CYCLES.times do |i|
          obj = JSON.parse(json, object_class: FooStruct)
          member = DATA.keys.sample
          "Value at #{i} for #{member}: #{obj.send(member)}"
        end
      end

      puts 'Struct with safety slicing'
      x.report do
        CYCLES.times do |i|
          obj = FooStruct.new(JSON.parse(json).slice(*FooStruct.members.map(&:to_s)))
          member = DATA.keys.sample
          "Value at #{i} for #{member}: #{obj.send(member)}"
        end
      end
    end
  end

  def json
    @json ||= DATA.to_json
  end

  FooStruct = Struct.new(:a, :b, :c, :d, :e, keyword_init: true)
end