Patch #28940
closed
Use Regexp#match? to reduce allocations of MatchData object
Description
since Rails 5.1+ we can use match? on a regex class safely even on older rubies
https://github.com/rails/rails/blob/5-1-stable/activesupport/lib/active_support/core_ext/regexp.rb
but the performance benefit is visible only on ruby 2.4+
https://bugs.ruby-lang.org/issues/8110
require 'benchmark/ips'
Benchmark.ips do |x|
x.report('match') { /test\d/.match 'test5'.freeze }
x.report('match?') { /test\d/.match? 'test5'.freeze }
x.compare!
end
Comparison:
match?: 4493322.3 i/s
match: 926754.9 i/s - 4.85x slower
rake test is about 5% faster
Files
Related issues
Updated by Pavel Rosický about 5 years ago
- File match_adapters.patch match_adapters.patch added
Updated by Go MAEDA about 5 years ago
It is a very interesting patch. But MailHandlerTest fails on my environment (Ruby 2.3).
$ ruby test/unit/mail_handler_test.rb
Run options: --seed 1974
# Running:
......................E
Error:
MailHandlerTest#test_truncate_emails_with_a_single_quoted_reply_should_truncate_the_email_at_the_delimiter_with_the_quoted_reply_symbols_(>):
NoMethodError: undefined method `match?' for #<String:0x007f91d84ebe90>
Did you mean? match
test/unit/mail_handler_test.rb:1005:in `block (2 levels) in <class:MailHandlerTest>'
test/test_helper.rb:93:in `with_settings'
test/unit/mail_handler_test.rb:1001:in `block in <class:MailHandlerTest>'
bin/rails test test/unit/mail_handler_test.rb:1000
........E
Error:
MailHandlerTest#test_truncate_emails_with_multiple_quoted_replies_should_truncate_the_email_at_the_delimiter_with_the_quoted_reply_symbols_(>):
NoMethodError: undefined method `match?' for #<String:0x007f91e3ad4d38>
Did you mean? match
test/unit/mail_handler_test.rb:1015:in `block (2 levels) in <class:MailHandlerTest>'
test/test_helper.rb:93:in `with_settings'
test/unit/mail_handler_test.rb:1011:in `block in <class:MailHandlerTest>'
bin/rails test test/unit/mail_handler_test.rb:1010
...........................................................
Finished in 21.213978s, 4.2896 runs/s, 20.2697 assertions/s.
91 runs, 430 assertions, 0 failures, 2 errors, 0 skips
The following sentence causes one of the error. Regexp.escape returns a String object. ActiveSupport defines Regexp#match? but does not String#match?.
assert !Regexp.escape("--- Reply above. Do not remove this line. ---").match?(journal.notes)
Updated by Pavel Rosický about 5 years ago
You're right. I will revert lines with Regexp.escape tomorrow, but otherwise it should work.
Updated by Mizuki ISHIKAWA about 5 years ago
+1
Redmine uses a lot of match methods.
I think it's wonderful that the test will be 5% faster.
Updated by Go MAEDA about 5 years ago
- Related to Patch #28939: replace regexp with casecmp added
Updated by Go MAEDA about 5 years ago
- File match-adapters-v2.diff match-adapters-v2.diff added
I have updated match-adapters.patch. The patch does not work due to syntax errors. "ActiveRecord::Base.connection.connection.adapter_name" must be replaced with "ActiveRecord::Base.connection.adapter_name" (one extra ".connection").
Updated by Go MAEDA about 5 years ago
- File match-v2.diff match-v2.diff added
Pavel Rosický wrote:
I will revert lines with Regexp.escape tomorrow,
Done. I am attaching an updated patch.
Updated by Go MAEDA about 5 years ago
- Target version set to Candidate for next major release
Updated by Go MAEDA almost 5 years ago
- Target version changed from Candidate for next major release to 4.1.0
Setting target version to 4.1.0.
Updated by Pavel Rosický almost 5 years ago
- File match_final.patch match_final.patch added
I combined all patches into a single file and I retested it on Ruby 2.3 and Ruby 2.4
Updated by Pavel Rosický about 4 years ago
- File match_final.patch match_final.patch added
Updated by Go MAEDA about 4 years ago
Pavel Rosický wrote:
I combined all patches into a single file and I retested it on Ruby 2.3 and Ruby 2.4
Thank you for updating the patch. I have confirmed that the patch passes all test in r18003.
Regexp#match? is faster than Regexp#match or =~ in most cases because it does not allocate MatchData object. I think there is no reason not to merge this patch.
Updated by Go MAEDA about 4 years ago
- Subject changed from reduce allocations to Use Regexp#match? to reduce allocations of MatchData object
- Assignee set to Go MAEDA
Committed the patch. Thank you for posting many performance-tuning patches.