From a5c9f24603da478366a7fa1a1279f13501e30bbe Mon Sep 17 00:00:00 2001 From: Dillon Welch Date: Mon, 23 Oct 2017 11:55:12 -0700 Subject: Performance improvements for acts_like? method. MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit activesupport/lib/active_support/core_ext/object/acts_like.rb acts_like? Add a case statement to use direct symbols instead of string interpolation for the three scenarios I found in the Rails codebase: time, date, and string. For time/date/string, this change prevents two string allocations for each time the method is called and speeds up the method by ~2.7x. For other arguments, there is no memory difference and performance difference is within margin of error. begin require "bundler/inline" rescue LoadError => e $stderr.puts "Bundler version 1.10 or later is required. Please update your Bundler" raise e end gemfile(true) do source "https://rubygems.org" gem "rails", github: "rails/rails" gem "arel", github: "rails/arel" gem "benchmark-ips" end def allocate_count GC.disable before = ObjectSpace.count_objects yield after = ObjectSpace.count_objects after.each { |k,v| after[k] = v - before[k] } after[:T_HASH] -= 1 # probe effect - we created the before hash. GC.enable result = after.reject { |k,v| v == 0 } GC.start result end class Object def fast_acts_like?(duck) case duck when :time respond_to? :acts_like_time? when :date respond_to? :acts_like_date? when :string respond_to? :acts_like_string? else respond_to? :"acts_like_#{duck}?" end end end puts puts " acts_like? ".center(80, '=') puts obj = ''.freeze %i(time date string super_hacka).each do |type| puts " #{type} ".center(80, '=') puts " Memory Usage ".center(80, "=") puts puts "value.acts_like?" puts allocate_count { 1000.times { obj.acts_like?(type) } } puts "value.fast_acts_like?" puts allocate_count { 1000.times { obj.fast_acts_like?(type) } } puts puts " Benchmark.ips ".center(80, "=") puts Benchmark.ips do |x| x.report("acts_like?") { obj.acts_like?(type) } x.report("fast_acts_like?") { obj.fast_acts_like?(type) } x.compare! end end ================================== acts_like? ================================== ===================================== time ===================================== ================================= Memory Usage ================================= value.acts_like? {:FREE=>-1983, :T_STRING=>2052, :T_IMEMO=>1} value.fast_acts_like? {:FREE=>-1} ================================ Benchmark.ips ================================= Warming up -------------------------------------- acts_like? 104.281k i/100ms fast_acts_like? 155.523k i/100ms Calculating ------------------------------------- acts_like? 1.688M (±10.7%) i/s - 8.342M in 5.003804s fast_acts_like? 4.596M (±12.1%) i/s - 22.551M in 5.000124s Comparison: fast_acts_like?: 4596162.4 i/s acts_like?: 1688163.8 i/s - 2.72x slower ===================================== date ===================================== ================================= Memory Usage ================================= value.acts_like? {:FREE=>-2001, :T_STRING=>2000} value.fast_acts_like? {:FREE=>-1} ================================ Benchmark.ips ================================= Warming up -------------------------------------- acts_like? 85.372k i/100ms fast_acts_like? 166.097k i/100ms Calculating ------------------------------------- acts_like? 1.720M (± 8.3%) i/s - 8.537M in 5.001003s fast_acts_like? 4.695M (±10.1%) i/s - 23.254M in 5.010734s Comparison: fast_acts_like?: 4695493.1 i/s acts_like?: 1719637.9 i/s - 2.73x slower ==================================== string ==================================== ================================= Memory Usage ================================= value.acts_like? {:FREE=>-2001, :T_STRING=>2000} value.fast_acts_like? {:FREE=>-1} ================================ Benchmark.ips ================================= Warming up -------------------------------------- acts_like? 100.221k i/100ms fast_acts_like? 182.841k i/100ms Calculating ------------------------------------- acts_like? 1.706M (± 7.3%) i/s - 8.519M in 5.022331s fast_acts_like? 3.968M (±22.8%) i/s - 18.650M in 5.006762s Comparison: fast_acts_like?: 3967972.9 i/s acts_like?: 1705773.7 i/s - 2.33x slower ================================= super_hacka ================================== ================================= Memory Usage ================================= value.acts_like? {:FREE=>-2004, :T_STRING=>2002, :T_SYMBOL=>1} value.fast_acts_like? {:FREE=>-2003, :T_STRING=>2001, :T_SYMBOL=>1} ================================ Benchmark.ips ================================= Warming up -------------------------------------- acts_like? 100.344k i/100ms fast_acts_like? 101.690k i/100ms Calculating ------------------------------------- acts_like? 1.617M (± 7.5%) i/s - 8.128M in 5.055285s fast_acts_like? 1.534M (±10.1%) i/s - 7.627M in 5.031052s Comparison: acts_like?: 1617390.7 i/s fast_acts_like?: 1533897.3 i/s - same-ish: difference falls within error --- activesupport/lib/active_support/core_ext/object/acts_like.rb | 11 ++++++++++- 1 file changed, 10 insertions(+), 1 deletion(-) diff --git a/activesupport/lib/active_support/core_ext/object/acts_like.rb b/activesupport/lib/active_support/core_ext/object/acts_like.rb index 2eb72f6b3a..403ee20e39 100644 --- a/activesupport/lib/active_support/core_ext/object/acts_like.rb +++ b/activesupport/lib/active_support/core_ext/object/acts_like.rb @@ -7,6 +7,15 @@ class Object # x.acts_like?(:date) to do duck-type-safe comparisons, since classes that # we want to act like Time simply need to define an acts_like_time? method. def acts_like?(duck) - respond_to? :"acts_like_#{duck}?" + case duck + when :time + respond_to? :acts_like_time? + when :date + respond_to? :acts_like_date? + when :string + respond_to? :acts_like_string? + else + respond_to? :"acts_like_#{duck}?" + end end end -- cgit v1.2.3