Create one big regular expresion for Rack::Attack

config/initializers/rack_attack.rb.example

@@ -9,18 +9,18 @@ paths_to_be_protected = [
   "#{Rails.application.config.relative_url_root}/api/#{API::API.version}/session",
   "#{Rails.application.config.relative_url_root}/users",
   "#{Rails.application.config.relative_url_root}/users/confirmation",
-  "#{Rails.application.config.relative_url_root}/unsubscribes/*"
+  "#{Rails.application.config.relative_url_root}/unsubscribes/"
 
 ]
 
-paths_to_be_protected.map! { |path| Regexp.new(path) }
+# Create one big regular expression that matches strings starting with any of
+# the paths_to_be_protected.
+paths_regex = Regexp.union(paths_to_be_protected.map { |path| /\A#{Regexp.escape(path)}/ })
 
 unless Rails.env.test?
   Rack::Attack.throttle('protected paths', limit: 10, period: 60.seconds) do |req|
-    if req.post?
-      paths_paths_to_be_protected.each do |protected_path|
-        req.ip if req.path =~ protected_path
-      end
+    if req.post? && req.path =~ paths_regex
+      req.ip
     end
   end
 end