From: "headius (Charles Nutter)" Date: 2013-10-03T20:21:32+09:00 Subject: [ruby-core:57639] [ruby-trunk - Feature #8977] String#frozen that takes advantage of the deduping Issue #8977 has been updated by headius (Charles Nutter). headius (Charles Nutter) wrote: > I ran this in a loop and the object_id eventually stabilizes. I am not sure why. I think I realize why: eventually the only GC is for the objects in the loop, which are allocated and deallocated the same way every time. So although a new fstring is defined each time, it lives at the same location in memory as the one from the previous loop. ---------------------------------------- Feature #8977: String#frozen that takes advantage of the deduping https://bugs.ruby-lang.org/issues/8977#change-42253 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/