integration perf test

Gemfile

@@ -49,6 +49,7 @@ gem 'transaction_retry' # mitigate https://github.com/lobsters/lobsters-ansible/
 gem 'rack-attack' # rate-limiting
 
 group :test, :development do
+  gem 'benchmark-perf'
   gem 'capybara'
   gem 'database_cleaner'
   gem "listen"

Gemfile.lock

@@ -76,6 +76,7 @@ GEM
     afm (0.2.2)
     ast (2.4.2)
     bcrypt (3.1.18)
+    benchmark-perf (0.6.0)
     builder (3.2.4)
     byebug (11.1.3)
     capybara (3.39.0)
@@ -324,6 +325,7 @@ DEPENDENCIES
   actionpack-page_caching
   activerecord-typedstore
   bcrypt (~> 3.1.2)
+  benchmark-perf
   byebug
   capybara
   commonmarker (>= 0.23.6)

script/comment_tree_perf.rb

@@ -0,0 +1,27 @@
+#!/usr/bin/env ruby
+
+# to use:
+# change force_ssl to false in config/environments/production.rb
+# SECRET_KEY_BASE=asdf rails server -e production -p 3000
+# be ruby script/comment_tree_perf.rb > [implementation].csv
+#
+# assumes a local server is running in prod mode with prod data
+
+APP_PATH = File.expand_path('../../config/application', __FILE__)
+require File.expand_path('../../config/boot', __FILE__)
+require APP_PATH
+Rails.application.require_environment!
+
+require 'benchmark-perf'
+
+puts "short_id,comments_count,avg,stdev,dt"
+
+Story.where('comments_count > 0').find_each(batch_size: 100) do |story|
+  # no warmup because the db difference on fetches is ~50%
+  # and we render old stories not in cache all day
+  result = Benchmark::Perf.cpu(warmup: 0, repeat: 10) do
+    `curl -qs http://localhost:3000/s/#{story.short_id} -o /dev/null`
+  end
+
+  puts "#{story.short_id},#{story.comments_count},#{result.avg},#{result.stdev},#{result.dt}"
+end

script/selected_bytepack_comment_tree.rb

@@ -11,14 +11,6 @@ end
 
 # max_depth_seen = 0
 
-# integration perf test: loop all stories and time rendering them 10x
-#   run w arrange_for_user
-#   run w selected
-#   run w selected_bytepack
-# better name for ord/ordpath
-# extract exploratory tests in test_bitpacking to test suite
-# future: replace confidence w ord
-
 Story.find_each(batch_size: 100) do |story|
   selected_comments = ActiveRecord::Base.connection.exec_query <<~SQL
     with recursive discussion as (