-
由 Dillon Welch 提交于
Do a check if the 'rel' argument is passed in, and simply set it to 'nofollow' if 'rel' was not passed in. This prevents three string allocations for each call to `link_to` in that scenario. In the scenario where the 'rel' argument is passed in, performance is around the same as before as the `key?` check is very fast. ```ruby 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 "benchmark-ips" gem "rails" 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 @hash = {} def master_version "#{@hash['rel'.freeze]} nofollow".lstrip end def fast_version if @hash.key?('rel'.freeze) "#{@hash["rel"]} nofollow".lstrip else "nofollow".freeze end end puts 'no rel key' puts "master_version" puts allocate_count { 1000.times { master_version } } puts "fast_version" puts allocate_count { 1000.times { fast_version } } Benchmark.ips do |x| x.report("master_version") { master_version } x.report("fast_version") { fast_version } x.compare! end puts 'rel key' @hash['rel'] = 'hi'.freeze puts "master_version" puts allocate_count { 1000.times { master_version } } puts "fast_version" puts allocate_count { 1000.times { fast_version } } Benchmark.ips do |x| x.report("master_version") { master_version } x.report("fast_version") { fast_version } x.compare! end ``` ``` no rel key master_version {:FREE=>-2791, :T_STRING=>3052} fast_version {:FREE=>-1} Warming up -------------------------------------- master_version 80.324k i/100ms fast_version 200.262k i/100ms Calculating ------------------------------------- master_version 2.049M (±11.9%) i/s - 10.121M in 5.025613s fast_version 6.645M (±21.3%) i/s - 29.439M in 5.007488s Comparison: fast_version: 6644506.3 i/s master_version: 2048833.0 i/s - 3.24x slower rel key master_version {:FREE=>-2001, :T_STRING=>2000} fast_version {:FREE=>-2001, :T_STRING=>2000} Warming up -------------------------------------- master_version 155.673k i/100ms fast_version 106.515k i/100ms Calculating ------------------------------------- master_version 2.652M (±20.4%) i/s - 12.610M in 5.036494s fast_version 2.237M (±16.8%) i/s - 10.865M in 5.035366s Comparison: master_version: 2651702.2 i/s fast_version: 2237470.6 i/s - same-ish: difference falls within error ```
f5f0b49b