Move caching into model

app/models/project.rb

@@ -675,10 +675,11 @@ class Project < ApplicationRecord
     # '>' or its escaped form ('&gt;') are checked for because '>' is sometimes escaped
     # when the reference comes from an external source.
     def markdown_reference_pattern
-      %r{
-        #{reference_pattern}
-        (#{reference_postfix}|#{reference_postfix_escaped})
-      }x
+      @markdown_reference_pattern ||=
+        %r{
+          #{reference_pattern}
+          (#{reference_postfix}|#{reference_postfix_escaped})
+        }x
     end
 
     def trending

lib/banzai/filter/project_reference_filter.rb

@@ -24,6 +24,7 @@ module Banzai
       end
 
       def call
+        ref_pattern = Project.markdown_reference_pattern
         ref_pattern_start = /\A#{ref_pattern}\z/
 
         nodes.each do |node|
@@ -82,7 +83,7 @@ module Banzai
         refs = Set.new
 
         nodes.each do |node|
-          node.to_html.scan(ref_pattern) do
+          node.to_html.scan(Project.markdown_reference_pattern) do
             refs << "#{$~[:namespace]}/#{$~[:project]}"
           end
         end
@@ -111,10 +112,6 @@ module Banzai
       def link_tag(url, data, link_content, title)
         %(<a href="#{url}" #{data} class="#{link_class}" title="#{escape_once(title)}">#{link_content}</a>)
       end
-
-      def ref_pattern
-        @ref_pattern ||= Project.markdown_reference_pattern
-      end
     end
   end
 end