Optimize system note visibility checking by hiding notes that

have been fully redacted and contain cross-project references.

The previous implementation relied on Note#cross_reference_not_visible_for?,
which essentially tries to render all the Markdown references in a system note
and only displays the note if the user can see the referring project. But this
duplicated the work that Banzai::NotesRenderer was doing already. Instead, for
each note we render, we memoize the number of visible user references and
use it later if it is available.

Improves #19273

1 files changed, 13 insertions, 1 deletions

diff --git a/app/models/note.rb b/app/models/note.rb
index ffffd0c0838..8dca2ef09a8 100644
--- a/app/models/note.rb
+++ b/app/models/note.rb
@@ -10,6 +10,10 @@ class Note < ActiveRecord::Base
   # Banzai::ObjectRenderer.
   attr_accessor :note_html
 
+  # An Array containing the number of visible references as generated by
+  # Banzai::ObjectRenderer
+  attr_accessor :user_visible_reference_count
+
   default_value_for :system, false
 
   attr_mentionable :note, pipeline: :note
@@ -193,7 +197,15 @@ class Note < ActiveRecord::Base
   end
 
   def cross_reference_not_visible_for?(user)
-    cross_reference? && referenced_mentionables(user).empty?
+    cross_reference? && !has_referenced_mentionables?(user)
+  end
+
+  def has_referenced_mentionables?(user)
+    if user_visible_reference_count.present?
+      user_visible_reference_count > 0
+    else
+      referenced_mentionables(user).any?
+    end
   end
 
   def award_emoji?