Bug #5696

rexml BaseParser uses instance_eval unnecessarily on listener add

Added by Charles Nutter over 2 years ago. Updated over 2 years ago.

[ruby-core:41437]
Status:Closed
Priority:Normal
Assignee:-
Category:lib
Target version:1.9.3
ruby -v:trunk Backport:

Description

In addlistener in REXML::BaseParser, there's code to instance eval and replace the old "pull" method with a new one that calls all listeners. I assume this was done to avoid the cost of calling .each on the listeners when there's none registered, but when the list is empty this call is nearly a no-op anyway. The singletonizing effect of instanceeval and the redefinition of #pull, on the other hand, cause a cache flush throughout the system.

I have created a patch that removes the instance_eval, initializes the listeners array unconditionally, and does the event #each unconditionally. It passes all tests, and should perform better because it's not damaging the cache.

https://gist.github.com/1420383

This can be safely backported to any Ruby version and has no visible behavior change.

Associated revisions

Revision 34202
Added by Ayumu AIZAWA over 2 years ago

  • lib/rexml/parsers/baseparser.rb: rexml BaseParser uses instance_eval unnecessarily on listener add. patch from Charles Nutter. [Bug #5696]

Revision 34204
Added by Kouhei Sutou over 2 years ago

  • lib/rexml/parsers/baseparser.rb: use private instead of _xxx method name. This is Ruby code not Python code. refs #5696

History

#1 Updated by Ayumu AIZAWA over 2 years ago

  • Status changed from Open to Closed
  • % Done changed from 0 to 100

This issue was solved with changeset r34202.
Charles, thank you for reporting this issue.
Your contribution to Ruby is greatly appreciated.
May Ruby be with you.


  • lib/rexml/parsers/baseparser.rb: rexml BaseParser uses instance_eval unnecessarily on listener add. patch from Charles Nutter. [Bug #5696]

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