Feature #17287
Faster Pathname FileUtils methods
Description
I have a patch that I would like to merge into Pathname for increased performance. I understand that akr maintains pathname and may not be on GitHub. Here is a link to my patch:
https://github.com/ruby/ruby/pull/3693
Here is the diff:
$ git diff master diff --git a/ext/pathname/lib/pathname.rb b/ext/pathname/lib/pathname.rb index e6fb90277d..c3af24837f 100644 --- a/ext/pathname/lib/pathname.rb +++ b/ext/pathname/lib/pathname.rb @@ -575,12 +575,13 @@ def find(ignore_error: true) # :yield: pathname class Pathname # * FileUtils * + autoload(:FileUtils, 'fileutils') + # Creates a full path, including any intermediate directories that don't yet # exist. # # See FileUtils.mkpath and FileUtils.mkdir_p def mkpath - require 'fileutils' FileUtils.mkpath(@path) nil end @@ -591,7 +592,6 @@ def mkpath def rmtree # The name "rmtree" is borrowed from File::Path of Perl. # File::Path provides "mkpath" and "rmtree". - require 'fileutils' FileUtils.rm_r(@path) nil end
Description¶
Currently when calling any of the "FileUtils" methods on pathname require
is called every time even though that library might already be loaded. This is slow.
We can speed it up by either checking first if the constant is already defined, or by using autoload.
Using defined speeds up the action by about 300x and using autoload is about twice as fast as that (600x faster than current require method).
I'm proposing we use autoload:
require 'benchmark/ips'
Benchmark.ips do |x|
autoload(:FileUtils, "fileutils")
x.report("require") { require 'fileutils' }
x.report("defined") { require 'fileutils' unless defined?(FileUtils) }
x.report("autoload") { FileUtils }
x.compare!
end
# Warming up --------------------------------------
# require 3.624k i/100ms
# defined 1.465M i/100ms
# autoload 2.320M i/100ms
# Calculating -------------------------------------
# require 36.282k (± 2.4%) i/s - 184.824k in 5.097153s
# defined 14.539M (± 2.0%) i/s - 73.260M in 5.041161s
# autoload 23.100M (± 1.9%) i/s - 115.993M in 5.023271s
# Comparison:
# autoload: 23099779.2 i/s
# defined: 14538544.9 i/s - 1.59x (± 0.00) slower
# require: 36282.3 i/s - 636.67x (± 0.00) slower
Because this autoload is scoped to Pathname it will not change the behavior of existing programs that are not expecting FileUtils to be loaded yet:
ruby -rpathname -e "class Pathname; autoload(:FileUtils, 'fileutils'); end; puts FileUtils.exist?('foo')" Traceback (most recent call last): -e:1:in `<main>': uninitialized constant FileUtils (NameError)
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