# frozen_string_literal: true

#
# This benchmark measures the efficiency of NamespaceCache.
#
# Run it multiple times with cache on/off to see the results:
#
#   $ bundle exec ruby namespaced_lookup_cache.rb
#   $ bundle exec ruby namespaced_lookup_cache.rb
#   $ NO_CACHE=1 bundle exec ruby namespaced_lookup_cache.rb
#   $ NO_CACHE=1 bundle exec ruby namespaced_lookup_cache.rb
#

$LOAD_PATH.unshift File.expand_path("../lib", __dir__)

require "action_policy"
require "benchmark/ips"

GC.disable

class A; end

class B; end

module X
  class BPolicy < ActionPolicy::Base; end

  module Y
    module Z
      class APolicy < ActionPolicy::Base; end
    end
  end
end

a = A.new
b = B.new

if ENV["NO_CACHE"]
  ActionPolicy::LookupChain.namespace_cache_enabled = false
end

results_path = File.join(__dir__, "../tmp/#{__FILE__.sub(/\.rb$/, ".txt")}")
FileUtils.mkdir_p File.dirname(results_path)

Benchmark.ips do |x|
  x.warmup = 0

  x.report("cache A") do
    ActionPolicy.lookup(a, namespace: X::Y::Z)
  end

  x.report("cache B") do
    ActionPolicy.lookup(b, namespace: X::Y::Z)
  end

  x.report("no cache A") do
    ActionPolicy.lookup(a, namespace: X::Y::Z)
  end

  x.report("no cache B") do
    ActionPolicy.lookup(b, namespace: X::Y::Z)
  end

  x.hold! results_path

  x.compare!
end

#
# Comparison:
#             cache A:   204788.3 i/s
#             cache B:   202536.9 i/s - same-ish: difference falls within error
#          no cache A:   127772.8 i/s - same-ish: difference falls within error
#          no cache B:    63487.2 i/s - 3.23x  slower