1 Mar
2023
1 Mar
'23
11:13 a.m.
Issue #18572 has been updated by Eregon (Benoit Daloze).
From https://bugs.ruby-lang.org/issues/14083#note-3 it seems part of the problem at least
is CRuby currently implements what I would call invalid usages of refinements (different
set of activates refinements over time for a given call site), and that basically means
extra checks and overhead, e.g., for a method which was refined once, even if there are no
refinements active in the current scope.
----------------------------------------
Bug #18572: Performance regression when invoking refined methods
https://bugs.ruby-lang.org/issues/18572#change-102092
* Author: palkan (Vladimir Dementyev)
* Status: Assigned
* Priority: Normal
* Assignee: ko1 (Koichi Sasada)
* Backport: 2.6: UNKNOWN, 2.7: UNKNOWN, 3.0: UNKNOWN, 3.1: UNKNOWN
----------------------------------------
Since Ruby 3.0, defining a refinement for a method slows down its execution even if we do
not activate the refinement:
```ruby
require "benchmark_driver"
source = <<~RUBY
class Hash
def symbolize_keys
transform_keys { |key| key.to_sym rescue key }
end
def refined_symbolize_keys
transform_keys { |key| key.to_sym rescue key }
end
end
module HashRefinements
refine Hash do
def refined_symbolize_keys
raise "never called"
end
end
end
HASH = {foo: 1, bar: 2, baz: 3}
class Foo
def original
end
def refined
end
end
module FooRefinements
refine Foo do
def refined
raise "never called"
end
end
end
FOO = Foo.new
RUBY
Benchmark.driver do |x|
x.prelude %Q{
#{source}
}
x.report "#symbolize_keys original", %{ HASH.symbolize_keys }
x.report "#symbolize_keys refined", %{ HASH.refined_symbolize_keys }
end
Benchmark.driver do |x|
x.prelude %Q{
#{source}
}
x.report "no-op original", %{ FOO.original }
x.report "no-op refined", %{ FOO.refined }
end
```
The results for Ruby 3.1:
```sh
...
Comparison:
#symbolize_keys original: 2372420.1 i/s
#symbolize_keys refined: 1941019.0 i/s - 1.22x slower
...
Comparison:
no-op original: 51790974.2 i/s
no-op refined: 14456518.9 i/s - 3.58x slower
```
For Ruby 2.6 and 2.7:
```sh
Comparison:
#symbolize_keys original: 2278339.7 i/s
#symbolize_keys refined: 2264153.1 i/s - 1.01x slower
...
Comparison:
no-op refined: 64178338.5 i/s
no-op original: 63357980.1 i/s - 1.01x slower
```
You can find the full code and more results in this
[gist](https://gist.github.com/palkan/637dc83edd86d70b5dbf72f2a4d702e5).
P.S. The problem was originally noticed by @byroot, see
https://github.com/ruby-i18n/i18n/pull/573
--
https://bugs.ruby-lang.org/