Merge pull request #30782 from NickLaMuro/improve_performance_of_inflections

Cache regexps generated from acronym_regex

actionpack/test/dispatch/request_test.rb

@@ -763,7 +763,7 @@ class RequestMethod < BaseRequestTest
 
   test "post uneffected by local inflections" do
     existing_acronyms = ActiveSupport::Inflector.inflections.acronyms.dup
-    existing_acronym_regex = ActiveSupport::Inflector.inflections.acronym_regex.dup
+    assert_deprecated { ActiveSupport::Inflector.inflections.acronym_regex.dup }
     begin
       ActiveSupport::Inflector.inflections do |inflect|
         inflect.acronym "POS"
@@ -777,7 +777,7 @@ class RequestMethod < BaseRequestTest
       # Reset original acronym set
       ActiveSupport::Inflector.inflections do |inflect|
         inflect.send(:instance_variable_set, "@acronyms", existing_acronyms)
-        inflect.send(:instance_variable_set, "@acronym_regex", existing_acronym_regex)
+        inflect.send(:define_acronym_regex_patterns)
       end
     end
   end

activesupport/lib/active_support/deprecation/constant_accessor.rb

@@ -1,7 +1,5 @@
 # frozen_string_literal: true
 
-require "active_support/inflector/methods"
-
 module ActiveSupport
   class Deprecation
     # DeprecatedConstantAccessor transforms a constant into a deprecated one by
@@ -29,6 +27,8 @@ module ActiveSupport
     #        ["Mercury", "Venus", "Earth", "Mars", "Jupiter", "Saturn", "Uranus", "Neptune"]
     module DeprecatedConstantAccessor
       def self.included(base)
+        require "active_support/inflector/methods"
+
         extension = Module.new do
           def const_missing(missing_const_name)
             if class_variable_defined?(:@@_deprecated_constants)

activesupport/lib/active_support/deprecation/proxy_wrappers.rb

@@ -1,6 +1,5 @@
 # frozen_string_literal: true
 
-require "active_support/inflector/methods"
 require "active_support/core_ext/regexp"
 
 module ActiveSupport
@@ -125,6 +124,8 @@ module ActiveSupport
     #        ["Mercury", "Venus", "Earth", "Mars", "Jupiter", "Saturn", "Uranus", "Neptune"]
     class DeprecatedConstantProxy < DeprecationProxy
       def initialize(old_const, new_const, deprecator = ActiveSupport::Deprecation.instance, message: "#{old_const} is deprecated! Use #{new_const} instead.")
+        require "active_support/inflector/methods"
+
         @old_const = old_const
         @new_const = new_const
         @deprecator = deprecator

activesupport/lib/active_support/inflector/inflections.rb

@@ -4,6 +4,7 @@ require "concurrent/map"
 require "active_support/core_ext/array/prepend_and_append"
 require "active_support/core_ext/regexp"
 require "active_support/i18n"
+require "active_support/deprecation"
 
 module ActiveSupport
   module Inflector
@@ -67,16 +68,21 @@ module ActiveSupport
       end
 
       attr_reader :plurals, :singulars, :uncountables, :humans, :acronyms, :acronym_regex
+      deprecate :acronym_regex
+
+      attr_reader :acronyms_camelize_regex, :acronyms_underscore_regex # :nodoc:
 
       def initialize
-        @plurals, @singulars, @uncountables, @humans, @acronyms, @acronym_regex = [], [], Uncountables.new, [], {}, /(?=a)b/
+        @plurals, @singulars, @uncountables, @humans, @acronyms = [], [], Uncountables.new, [], {}
+        define_acronym_regex_patterns
       end
 
       # Private, for the test suite.
       def initialize_dup(orig) # :nodoc:
-        %w(plurals singulars uncountables humans acronyms acronym_regex).each do |scope|
+        %w(plurals singulars uncountables humans acronyms).each do |scope|
           instance_variable_set("@#{scope}", orig.send(scope).dup)
         end
+        define_acronym_regex_patterns
       end
 
       # Specifies a new acronym. An acronym must be specified as it will appear
@@ -130,7 +136,7 @@ module ActiveSupport
       #   camelize 'mcdonald'   # => 'McDonald'
       def acronym(word)
         @acronyms[word.downcase] = word
-        @acronym_regex = /#{@acronyms.values.join("|")}/
+        define_acronym_regex_patterns
       end
 
       # Specifies a new pluralization rule and its replacement. The rule can
@@ -225,6 +231,14 @@ module ActiveSupport
           instance_variable_set "@#{scope}", []
         end
       end
+
+      private
+
+        def define_acronym_regex_patterns
+          @acronym_regex             = @acronyms.empty? ? /(?=a)b/ : /#{@acronyms.values.join("|")}/
+          @acronyms_camelize_regex   = /^(?:#{@acronym_regex}(?=\b|[A-Z_])|\w)/
+          @acronyms_underscore_regex = /(?:(?<=([A-Za-z\d]))|\b)(#{@acronym_regex})(?=\b|[^a-z])/
+        end
     end
 
     # Yields a singleton instance of Inflector::Inflections so you can specify

activesupport/lib/active_support/inflector/methods.rb

@@ -71,7 +71,7 @@ module ActiveSupport
       if uppercase_first_letter
         string = string.sub(/^[a-z\d]*/) { |match| inflections.acronyms[match] || match.capitalize }
       else
-        string = string.sub(/^(?:#{inflections.acronym_regex}(?=\b|[A-Z_])|\w)/) { |match| match.downcase }
+        string = string.sub(inflections.acronyms_camelize_regex) { |match| match.downcase }
       end
       string.gsub!(/(?:_|(\/))([a-z\d]*)/i) { "#{$1}#{inflections.acronyms[$2] || $2.capitalize}" }
       string.gsub!("/".freeze, "::".freeze)
@@ -92,7 +92,7 @@ module ActiveSupport
     def underscore(camel_cased_word)
       return camel_cased_word unless /[A-Z-]|::/.match?(camel_cased_word)
       word = camel_cased_word.to_s.gsub("::".freeze, "/".freeze)
-      word.gsub!(/(?:(?<=([A-Za-z\d]))|\b)(#{inflections.acronym_regex})(?=\b|[^a-z])/) { "#{$1 && '_'.freeze }#{$2.downcase}" }
+      word.gsub!(inflections.acronyms_underscore_regex) { "#{$1 && '_'.freeze }#{$2.downcase}" }
       word.gsub!(/([A-Z\d]+)([A-Z][a-z])/, '\1_\2'.freeze)
       word.gsub!(/([a-z\d])([A-Z])/, '\1_\2'.freeze)
       word.tr!("-".freeze, "_".freeze)

activesupport/test/inflector_test.rb

@@ -224,6 +224,12 @@ class InflectorTest < ActiveSupport::TestCase
     assert_equal("json_html_api", ActiveSupport::Inflector.underscore("JSONHTMLAPI"))
   end
 
+  def test_acronym_regexp_is_deprecated
+    assert_deprecated do
+      ActiveSupport::Inflector.inflections.acronym_regex
+    end
+  end
+
   def test_underscore
     CamelToUnderscore.each do |camel, underscore|
       assert_equal(underscore, ActiveSupport::Inflector.underscore(camel))