alekseyl

# This is a simple gist for performance and RAM usage testing for a nested_select gem
# 
# Objects relations: course -> topics -> lessons ( all relations are has_many )
# 
# ------------------------------------------------------------------------- 
# Schemas: 
# 
#   create_table "lessons", force: :cascade do |t|
#     t.string "title", null: false, comment: "Тема урока"
#     t.string "description", null: false, comment: "Описание урока"

alekseyl

require 'memory_profiler'
require 'terminal-table'

def compare_ram(scope, base_collection_size, nesting)
  ids = scope.ids
  ids_sample = ids.sample(base_collection_size) # it should be the same id for both tests, since we comparing memory consumption

  # just to keep from memory profiler objects oblivion, and get retain numbers correctly
  el, pr = []
  preload = MemoryProfiler.report do

alekseyl

def compare_cpu_general( scope, base_collection_size, nesting)
  ids = scope.ids
  ActiveRecord::Base.logger.silence do
    Benchmark.bmbm do |benchmark|
       benchmark.report("eager_load") do
        50.times do
          # sample(base_collection_size + 1) and limit(base_collection_size) 
          # added to imitate real limit for eager_load, so it would be obligated to use 2 queries instead of one
          # for more read here: https://medium.com/p/5ce11870de62
          scope.where(id: ids.sample(base_collection_size + 1)).limit(base_collection_size).eager_load(nesting).load