Performance issue in String#codepoints

[jabamaus]

Hi,

I've written an app that runs with mruby or cruby and I noticed that the frame rate was massively degraded when running with mruby. After investigation I narrowed it down to calls to String#codepoints which where happening multiple times per frame. Of course I can, and probably will improve my code to use a cache or eliminate it entirely but I think the method itself can be hugely optimized, after all the way its currently written works fine in cruby.

The implementation in https://github.com/mruby/mruby/blob/master/mrbgems/mruby-string-ext/mrblib/string.rb is:

self.split('').map{|x| x.ord}
I think this is made worse by the fact that the onig_regexp gem replaces String#split with its own version which probably adds a further performance penalty.

Presumably the GC is getting hammered. I guess doing it in C would be the best?

I'm not desperate for this but I thought I'd flag it.

Cheers!

[0x1eef]

Are you passing a block ? Maybe it is more efficient to use yield instead.
And I think split could be avoided with each_char.
It is a shot in the dark though.

def codepoints
  if block_given?
    each_char { |c| yield(c.ord) }
    self
  else
    each_char.map { |c| c.ord }
  end
end

[matz]

We implemented part of codepoints in C. Now it's even faster than CRuby (in cases we tested).

[jabamaus]

Heh heh, that’s the spirit! Thanks!

…

On Sat, 23 Sep 2023 at 03:37, matz ***@***.***> wrote: We implemented part of codepoints in C. Now it's even faster than CRuby (in cases we tested). — Reply to this email directly, view it on GitHub <#6061 (comment)>, or unsubscribe <https://github.com/notifications/unsubscribe-auth/AL2MVMUVHILRJDC4INYPBLLX3ZDO3ANCNFSM6AAAAAA5BM4TUU> . You are receiving this because you authored the thread.Message ID: ***@***.***>