Store discussion_id on Note for faster discussion lookup.

1 files changed, 26 insertions, 9 deletions

diff --git a/app/models/note.rb b/app/models/note.rb
index 732b2ff9bf7..fb0d0ebc396 100644
--- a/app/models/note.rb
+++ b/app/models/note.rb
@@ -70,7 +70,9 @@ class Note < ActiveRecord::Base
              project: [:project_members, { group: [:group_members] }])
   end
 
+  after_initialize :ensure_discussion_id
   before_validation :nullify_blank_type, :nullify_blank_line_code
+  before_validation :set_discussion_id
   after_save :keep_around_commit
 
   class << self
@@ -82,6 +84,10 @@ class Note < ActiveRecord::Base
       [:discussion, noteable_type.try(:underscore), noteable_id].join("-")
     end
 
+    def self.discussion_id(*args)
+      Digest::SHA1.hexdigest(build_discussion_id(*args))
+    end
+
     def discussions
       Discussion.for_notes(all)
     end
@@ -142,15 +148,6 @@ class Note < ActiveRecord::Base
     resolvable? && !resolved?
   end
 
-  def discussion_id
-    @discussion_id ||=
-      if for_merge_request?
-        Digest::SHA1.hexdigest([:discussion, :note, id].join("-"))
-      else
-        Digest::SHA1.hexdigest(self.class.build_discussion_id(noteable_type, noteable_id || commit_id))
-      end
-  end
-
   def max_attachment_size
     current_application_settings.max_attachment_size.megabytes.to_i
   end
@@ -256,4 +253,24 @@ class Note < ActiveRecord::Base
   def nullify_blank_line_code
     self.line_code = nil if self.line_code.blank?
   end
+
+  def ensure_discussion_id
+    return unless self.persisted?
+    return if self.discussion_id
+
+    set_discussion_id
+    update_column(:discussion_id, self.discussion_id)
+  end
+
+  def set_discussion_id
+    self.discussion_id = Digest::SHA1.hexdigest(build_discussion_id)
+  end
+
+  def build_discussion_id
+    if for_merge_request?
+      [:discussion, :note, id].join("-")
+    else
+      self.class.build_discussion_id(noteable_type, noteable_id || commit_id)
+    end
+  end
 end