From: "charliesome (Charlie Somerville)" Date: 2013-10-02T14:00:13+09:00 Subject: [ruby-core:57584] [ruby-trunk - Feature #8977] String#frozen that takes advantage of the deduping Issue #8977 has been updated by charliesome (Charlie Somerville). Target version set to current: 2.1.0 I would love to see this feature in 2.1. These are the top duplicated strings in an app I work on: irb(main):023:0> GC.start; h = ObjectSpace.each_object(String).to_a.group_by { |s| s }.map{ |s, objs| [s, objs.size] }; h.sort_by { |s, count| -count }.take(10).each do |s| p s end; nil ["/", 5241] ["(eval)", 3207] ["application", 2389] ["", 1908] ["html.erb", 1720] ["base64", 1520] ["erb", 1464] ["IANA", 1389] ["initialize", 1147] ["recognize", 1036] Most of these could be deduplicated with String#frozen. ---------------------------------------- Feature #8977: String#frozen that takes advantage of the deduping https://bugs.ruby-lang.org/issues/8977#change-42198 Author: sam.saffron (Sam Saffron) Status: Open Priority: Normal Assignee: Category: Target version: current: 2.1.0 During memory profiling I noticed that a large amount of string duplication is generated from non pre-determined strings. Take this report for example https://gist.github.com/SamSaffron/6789005 (generated using the memory_profiler gem that works against head) ">=" x 4953 /Users/sam/.rbenv/versions/2.1.0-dev/lib/ruby/2.1.0/rubygems/requirement.rb:93 x 4535 This string is most likely extracted from a version. Or "/Users/sam/.rbenv/versions/2.1.0-dev/lib/ruby/gems" x 5808 /Users/sam/.rbenv/versions/2.1.0-dev/lib/ruby/gems/2.1.0/gems/activesupport-3.2.12/lib/active_support/dependencies.rb:251 x 3894 A string that can not be pre-determined. ---- It would be nice to have "hello,world".split(",")[0].frozen.object_id == "hello"f.object_id Adding #frozen will give library builders a way of using the de-duping. It also could be implemented using weak refs in 2.0 and stubbed with a .dup.freeze in 1.9.3 . Thoughts ? -- http://bugs.ruby-lang.org/