TICKET-574: Implement assignment caching

Changelog.md

@@ -11,6 +11,7 @@
 - Update autotest settings form UI (#7777)
 - Store start and end date for courses (#7783)
 - Update batch test runs table UI (#7790)
+- Implement assignment caching (#7787)
 
 ### 🐛 Bug fixes
 - Fixed the editing form of marking schemes to include newly added assessments (#7788)

app/models/assignment.rb

@@ -940,6 +940,65 @@ def get_num_marked(ta_id = nil, bulk: false)
     end
   end
 
+  # Batch load TA stats for multiple assignments to avoid N+1 queries.
+  # Returns { assignment_id => { num_assigned: Integer, num_marked: Integer } }
+  def self.batch_ta_stats(assignments, ta_id)
+    return {} if ta_id.nil? || assignments.empty?
+
+    assignment_ids = assignments.map(&:id)
+
+    # Query 1: Count assigned groupings per assignment
+    assigned_counts = TaMembership
+                      .joins(:grouping)
+                      .where(role_id: ta_id, groupings: { assessment_id: assignment_ids })
+                      .group('groupings.assessment_id')
+                      .count
+
+    # Identify criteria-based assignments for this TA
+    criteria_assignment_ids = CriterionTaAssociation
+                              .joins(:criterion)
+                              .where(ta_id: ta_id, criteria: { assessment_id: assignment_ids })
+                              .distinct
+                              .pluck('criteria.assessment_id')
+
+    criteria_based_ids = assignments
+                         .select { |a| a.assign_graders_to_criteria && criteria_assignment_ids.include?(a.id) }
+                         .map(&:id)
+
+    regular_ids = assignment_ids - criteria_based_ids
+
+    # Query 2: Count marked results for non-criteria-based assignments
+    marked_counts = if regular_ids.any?
+                      Result
+                        .joins(submission: { grouping: :ta_memberships })
+                        .where(
+                          submissions: { submission_version_used: true },
+                          memberships: { role_id: ta_id },
+                          groupings: { assessment_id: regular_ids },
+                          marking_state: Result::MARKING_STATES[:complete]
+                        )
+                        .group('groupings.assessment_id')
+                        .count
+                    else
+                      {}
+                    end
+
+    # Build result hash
+    result = {}
+    assignments.each do |a|
+      num_marked = if criteria_based_ids.include?(a.id)
+                     a.get_num_marked(ta_id) # Fall back for criteria-based
+                   else
+                     marked_counts[a.id] || 0
+                   end
+      result[a.id] = {
+        num_assigned: assigned_counts[a.id] || 0,
+        num_marked: num_marked
+      }
+    end
+    result
+  end
+
   def get_num_annotations(ta_id = nil)
     if ta_id.nil?
       num_annotations_all

app/views/assignments/_list_manage.html.erb

@@ -2,6 +2,7 @@
                                 .includes(:submission_rule, :assessment_section_properties, :pr_assignment)
                                 .order(:due_date, :short_identifier) %>
 <% action = @current_role.instructor? ? 'edit' : 'summary' %>
+<% ta_stats = @current_role.ta? ? Assignment.batch_ta_stats(assignments, @current_role.id) : {} %>
 
 <% if assignments.empty? %>
   <p><%= t('assignments.none') %></p>
@@ -39,12 +40,17 @@
                 </span>
               <% end %>
               <% if assignment.submission_rule.can_collect_all_now? %>
-                <% ta_id = @current_role.instructor? ? nil : @current_role.id %>
                 <br>
                 <span>
-                  <%= t('submissions.how_many_marked',
-                        num_marked: assignment.get_num_marked(ta_id),
-                        num_assigned: assignment.get_num_assigned(ta_id)) %>
+                  <% if ta_stats[assignment.id] %>
+                    <%= t('submissions.how_many_marked',
+                          num_marked: ta_stats[assignment.id][:num_marked],
+                          num_assigned: ta_stats[assignment.id][:num_assigned]) %>
+                  <% else %>
+                    <%= t('submissions.how_many_marked',
+                          num_marked: assignment.get_num_marked,
+                          num_assigned: assignment.get_num_assigned) %>
+                  <% end %>
                 </span>
                 <br>
                 <%= link_to t('assignments.grades'),

spec/models/assignment_spec.rb

@@ -2804,6 +2804,88 @@ def grouping_count(groupings)
     end
   end
 
+  describe '#get_num_assigned' do
+    let(:ta) { create(:ta) }
+    let(:assignment) { create(:assignment) }
+    let!(:grouping1) { create(:grouping_with_inviter, assignment: assignment) }
+    let!(:grouping2) { create(:grouping_with_inviter, assignment: assignment) }
+
+    before do
+      create(:grouping_with_inviter, assignment: assignment) # grouping3 - not assigned to TA
+      create(:ta_membership, role: ta, grouping: grouping1)
+      create(:ta_membership, role: ta, grouping: grouping2)
+    end
+
+    context 'when user is instructor' do
+      it 'returns total number of groupings' do
+        expect(assignment.get_num_assigned).to eq(3)
+      end
+    end
+
+    context 'when user is TA' do
+      it 'returns number of groupings assigned to them' do
+        expect(assignment.get_num_assigned(ta.id)).to eq(2)
+      end
+    end
+  end
+
+  describe '.batch_ta_stats' do
+    let(:ta) { create(:ta) }
+    let(:assignment1) { create(:assignment) }
+    let(:assignment2) { create(:assignment) }
+
+    let(:grouping1) { create(:grouping_with_inviter_and_submission, assignment: assignment1, is_collected: true) }
+    let(:grouping2) { create(:grouping_with_inviter_and_submission, assignment: assignment1, is_collected: true) }
+    let(:grouping3) { create(:grouping_with_inviter_and_submission, assignment: assignment2, is_collected: true) }
+
+    before do
+      create(:complete_result, submission: grouping1.submissions.first)
+      create(:incomplete_result, submission: grouping2.submissions.first)
+      create(:complete_result, submission: grouping3.submissions.first)
+      create(:ta_membership, role: ta, grouping: grouping1)
+      create(:ta_membership, role: ta, grouping: grouping2)
+      create(:ta_membership, role: ta, grouping: grouping3)
+    end
+
+    it 'returns empty hash when ta_id is nil' do
+      expect(Assignment.batch_ta_stats([assignment1, assignment2], nil)).to eq({})
+    end
+
+    it 'returns empty hash when assignments is empty' do
+      expect(Assignment.batch_ta_stats([], ta.id)).to eq({})
+    end
+
+    it 'returns correct stats for multiple assignments' do
+      stats = Assignment.batch_ta_stats([assignment1, assignment2], ta.id)
+
+      expect(stats[assignment1.id][:num_assigned]).to eq(2)
+      expect(stats[assignment1.id][:num_marked]).to eq(1)
+      expect(stats[assignment2.id][:num_assigned]).to eq(1)
+      expect(stats[assignment2.id][:num_marked]).to eq(1)
+    end
+
+    context 'when assignment has criteria-based grading' do
+      let(:assignment3) do
+        create(:assignment_with_criteria_and_results_with_remark,
+               assignment_properties_attributes: { assign_graders_to_criteria: true })
+      end
+      let(:grouping4) { create(:grouping_with_inviter_and_submission, assignment: assignment3) }
+
+      before do
+        create(:ta_membership, role: ta, grouping: assignment3.groupings.first)
+        create(:ta_membership, role: ta, grouping: grouping4)
+        create(:criterion_ta_association, ta: ta, criterion: assignment3.criteria.first)
+      end
+
+      it 'falls back to get_num_marked for criteria-based assignments' do
+        stats = Assignment.batch_ta_stats([assignment3], ta.id)
+
+        expect(stats[assignment3.id][:num_assigned]).to eq(2)
+        expect(stats[assignment3.id][:num_marked]).to eq(assignment3.get_num_marked(ta.id))
+      end
+    end
+  end
+
   describe '#completed_result_marks' do
     let(:assignment) { create(:assignment) }
     let!(:criteria) { create_list(:rubric_criterion, 2, assignment: assignment, max_mark: 4) }