From: matthew@...
Date: 2014-12-25T00:58:34+00:00
Subject: [ruby-core:67116] [ruby-trunk - Bug #10015] Performance regression	in Dir#[]

Issue #10015 has been updated by Matthew Draper.


I don't know what I'm talking about, but this seems like it could use `fcntl(2)` + `F_GETPATH`, or `getattrlist(2)` + `ATTR_CMN_NAME`.. or something along those lines -- we shouldn't need the loop+fnmatch at all, should we?

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Bug #10015: Performance regression in Dir#[]
https://bugs.ruby-lang.org/issues/10015#change-50621

* Author: Aaron Patterson
* Status: Closed
* Priority: Normal
* Assignee: 
* Category: 
* Target version: 
* ruby -v: ruby 2.2.0dev (2014-02-04 trunk 44802) [x86_64-darwin13.0]
* Backport: 2.0.0: UNKNOWN, 2.1: UNKNOWN
----------------------------------------
r44802 seems to have introduced a performance regression in Dir#[].

Here is the test program:

~~~ruby
require 'benchmark'

puts Benchmark.realtime {
  glob = "minitest/*_plugin.rb{,.rb,.bundle}"
  $LOAD_PATH.map { |load_path|
    Dir["#{File.expand_path glob, load_path}"]
  }.flatten.select { |file| File.file? file.untaint }
}
~~~

Here is the test time for me:

~~~
$ ruby -v test.rb
ruby 2.2.0dev (2014-02-04 trunk 44801) [x86_64-darwin13.0]
0.000341
$ ruby -v test.rb
ruby 2.2.0dev (2014-02-04 trunk 44802) [x86_64-darwin13.0]
0.009333
~~~

r44801 seems much faster than r44802.



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