partial_cache.rb

require"benchmark/ips"
require"action_view"
require"action_pack"
require"action_controller"
require"active_record"
require"stackprof"

ActiveRecord::Base.establish_connection(adapter: "sqlite3",database: ":memory:")

ActiveRecord::Schema.definedo
create_table:customers,force: truedo |t|
t.string:name
end
end

classCustomer < ActiveRecord::Base;end

classTestController < ActionController::Base
end

ActionView::PartialRenderer.collection_cache=ActiveSupport::Cache::MemoryStore.new
TestController.view_paths=[File.expand_path("perf_scripts/partial_cache")]

putsTestController.view_paths

# Create a bunch of data

letters=("a".."z").to_a * 5
1000.times{Customer.create!(name: letters.sample(10).join)}

customers=Customer.all.to_a

controller_view=TestController.new.view_context

# Heat compilation cache and collection cache
controller_view.render("render_collection",customers: customers)
controller_view.render("render_collection_with_cache",customers: customers)

pActionView::PartialRenderer.collection_cache# 1000 entries

Benchmark.ipsdo |x|
x.report("collection render: no cache")do
controller_view.render("render_collection",customers: customers)
end

x.report("collection render: with cache")do
controller_view.render("render_collection_with_cache",customers: customers)
end

x.compare!
end