[ruby-core:120640] [Ruby master Bug#21032] `Module#autoload?` is slow when `$LOAD_PATH` contains a relative path

Issue #21032 has been updated by byroot (Jean Boussier).


@fxn tracked it down to https://github.com/emailage/Emailage_Ruby/blob/64b9762cda7608ac1eeced2a85ad5f4b7919f4f0/lib/emailage.rb#L1, and yes that's an anti-pattern in my opinion too.



----------------------------------------
Bug #21032: `Module#autoload?` is slow when `$LOAD_PATH` contains a relative path
https://bugs.ruby-lang.org/issues/21032#change-111469

* Author: byroot (Jean Boussier)
* Status: Open
* Backport: 3.1: WONTFIX, 3.2: REQUIRED, 3.3: REQUIRED, 3.4: REQUIRED
----------------------------------------
Reproduction script:

```ruby
require 'benchmark'

$LOAD_PATH << 'relative-path'

autoload :FOO, '/tmp/foo.rb'

puts Benchmark.realtime {
  500_000.times do
    Object.autoload?(:FOO)
  end
}
```

The above takes 2.5 to 3 seconds on my machine, but just removing `$LOAD_PATH << 'relative-path'` make it complete in 50ms.
It's such a stark difference that I think it is a bug, and it cause Zeitwerk, a very popular gem, to be way slower than it should
when the load path contains relative paths.

I have a patch for it, that passes all tests, but I'd appreciate some eyes on it: https://github.com/ruby/ruby/pull/12562

cc @fxn 



-- 
https://bugs.ruby-lang.org/
 ______________________________________________
 ruby-core mailing list -- [e-mail]
 To unsubscribe send an email to [e-mail]
 ruby-core info -- https://ml.ruby-lang.org/mailman3/lists/ruby-core.ml.ruby-lang.org/