From 503d334599a315e956928bb82febf1e226fb6100 Mon Sep 17 00:00:00 2001 From: Juanito Fatas Date: Sat, 12 Sep 2015 11:52:46 +0800 Subject: Improve String#strip_heredoc MIME-Version: 1.0 Content-Type: text/plain; charset=UTF-8 Content-Transfer-Encoding: 8bit Saves about 6 MB, about 40% faster. **strip_heredoc.rb** ```ruby require "active_support/core_ext/object/try" require "get_process_mem" class String def strip_heredoc indent = scan(/^[ \t]*(?=\S)/).min.try(:size) || 0 gsub(/^[ \t]{#{indent}}/, '') end end if ENV["MEASURE_MEMORY"] == "yes" mem = GetProcessMem.new GC.start GC.disable 10000.times do <<-MSG.strip_heredoc xhr and xml_http_request methods are deprecated in favor of `get :index, xhr: true` and `post :create, xhr: true` MSG end before = mem.mb after = mem.mb GC.enable puts "Before: #{before} MiB" puts "After: #{after} MiB" puts "Diff: #{after - before} MiB" end ``` **patched_strip_heredoc.rb** ```ruby require "active_support/core_ext/object/try" require "get_process_mem" class String def patched_strip_heredoc gsub(/^#{scan(/^[ \t]*(?=\S)/).min}/, "".freeze) end end if ENV["MEASURE_MEMORY"] == "yes" mem = GetProcessMem.new GC.start GC.disable 10000.times do <<-MSG.patched_strip_heredoc xhr and xml_http_request methods are deprecated in favor of `get :index, xhr: true` and `post :create, xhr: true` MSG end before = mem.mb after = mem.mb GC.enable puts "Before: #{before} MiB" puts "After: #{after} MiB" puts "Diff: #{after - before} MiB" end ``` **Before** ``` $ MEASURE_MEMORY=yes ruby strip_heredoc.rb Before: 44.73828125 MiB After: 44.7734375 MiB Diff: 0.03515625 MiB ``` **After** ``` $ MEASURE_MEMORY=yes ruby patched_strip_heredoc.rb Before: 37.9765625 MiB After: 38.015625 MiB Diff: 0.0390625 MiB ``` `44.7734375 - 38.015625 = 6.75` => **Saves about 6.75 MiB** **benchmark.rb** ```ruby require "benchmark/ips" require_relative "./strip_heredoc" require_relative "./patched_strip_heredoc" def original <<-MSG.strip_heredoc xhr and xml_http_request methods are deprecated in favor of `get :index, xhr: true` and `post :create, xhr: true` MSG end def patched <<-MSG.patched_strip_heredoc xhr and xml_http_request methods are deprecated in favor of `get :index, xhr: true` and `post :create, xhr: true` MSG end Benchmark.ips do |x| x.report("original") { original } x.report(" patched") { patched } x.compare! end ``` ``` $ ruby -v benchmark.rb ruby 2.2.2p95 (2015-04-13 revision 50295) [x86_64-darwin14] Calculating ------------------------------------- original 5.652k i/100ms patched 6.477k i/100ms ------------------------------------------------- original 54.076k (± 5.7%) i/s - 271.296k patched 74.557k (± 6.2%) i/s - 375.666k Comparison: patched: 74557.0 i/s original: 54076.4 i/s - 1.38x slower ``` => **About 38% faster** 1. Clone rails project `git clone git@github.com:rails/rails.git` 2. Apply this patch to `activesupport/lib/active_support/core_ext/string/strip.rb` 3. `cd activesupport` 4. run `rake` 5. And tests passed: ``` ➜ activesupport $ rake /Users/Juan/.rubies/ruby-2.2.2/bin/ruby -w -I"lib:test" "/Users/Juan/.rubies/ruby-2.2.2/lib/ruby/2.2.0/rake/rake_test_loader.rb" "test/**/*_test.rb" ........................................................................ ........................................................................ ........................................................................ ........................................................................ ........................................................................ ........................................................................ ........................................................................ ........................................................................ ........................................................................ ........................................................................ ........................................................................ ........................................................................ ........................................................................ ........................................................................ ........................................................................ ........................................................................ ........................................................................ ........................................................................ ........................................................................ ........................................................................ ........................................................................ ........................................................................ ........................................................................ ........................................................................ ........................................................................ ........................................................................ ........................................................................ ........................................................................ ........................................................................ ........................................................................ ........................................................................ ........................................................................ ........................................................................ ........................................................................ ........................................................................ ........................................................................ ........................................................................ ........................................................................ ........................................................................ ........................................................................ ........................................................................ ........................................................................ ........................................................................ ........................................................................ ......................................................................S. SSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSSS Finished in 15.343004s, 214.2344 runs/s, 24902.4898 assertions/s. 3287 runs, 382079 assertions, 0 failures, 0 errors, 48 skips You have skipped tests. Run with --verbose for details. ``` --- activesupport/lib/active_support/core_ext/string/strip.rb | 3 +-- 1 file changed, 1 insertion(+), 2 deletions(-) (limited to 'activesupport/lib/active_support/core_ext/string') diff --git a/activesupport/lib/active_support/core_ext/string/strip.rb b/activesupport/lib/active_support/core_ext/string/strip.rb index 9fdd9d8d2e..a523e76b69 100644 --- a/activesupport/lib/active_support/core_ext/string/strip.rb +++ b/activesupport/lib/active_support/core_ext/string/strip.rb @@ -20,7 +20,6 @@ class String # Technically, it looks for the least indented non-empty line # in the whole string, and removes that amount of leading whitespace. def strip_heredoc - indent = scan(/^[ \t]*(?=\S)/).min.try(:size) || 0 - gsub(/^[ \t]{#{indent}}/, '') + gsub(/^#{scan(/^[ \t]*(?=\S)/).min}/, ''.freeze) end end -- cgit v1.2.3