Caching Manage Submissions Page (#2276)

* Caching some data from index, todo fix caching issues for submission data

* Cached submission_ids instead of trying to do full data entries.

* Changed expiration time of cache entries and allow for cache remake after new submission.

* Uncommented necessary lines removed when testing.

* Finished adding functionality of caching manage submissions.

* Cleaned up code.

Author: jhs-panda

app/controllers/assessment/handin.rb

@@ -27,6 +27,10 @@ def handin
       return false
     end
 
+    # Clear cache since new submission made, need to remake cache
+    Rails.cache.delete(["submission_ids", @assessment.id])
+    Rails.cache.delete(["submissions_to_cud", @assessment.id])
+
     if @assessment.embedded_quiz
       contents = params[:submission]["embedded_quiz_form_answer"].to_s
       out_file = Tempfile.new('out.txt-')

app/controllers/submissions_controller.rb

@@ -17,17 +17,22 @@ class SubmissionsController < ApplicationController
 
   action_auth_level :index, :instructor
   def index
-    @submissions = @assessment.submissions.includes({ course_user_datum: :user })
-                              .order("created_at DESC")
+    # cache ids instead of entire entries
+    submission_ids = Rails.cache.fetch(["submission_ids", @assessment.id], expires_in: 1.day) do
+      @assessment.submissions.order("created_at DESC").pluck(:id)
+    end
+    @submissions = Submission.where(id: submission_ids).includes({ course_user_datum: :user })
     @autograded = @assessment.has_autograder?
 
-    @submissions_to_cud = {}
-    @submissions.each do |submission|
-      currSubId = submission.id
-      currCud = submission.course_user_datum_id
-      @submissions_to_cud[currSubId] = currCud
-    end
-    @submissions_to_cud = @submissions_to_cud.to_json
+    @submissions_to_cud =
+      Rails.cache.fetch(["submissions_to_cud", @assessment.id], expires_in: 1.day) do
+        submissions_to_cud = {}
+        @submissions.each do |submission|
+          submissions_to_cud[submission.id] = submission.course_user_datum_id
+        end
+        submissions_to_cud.to_json
+      end
+
     @excused_cids = []
     excused_students = AssessmentUserDatum.where(
       assessment_id: @assessment.id,
@@ -80,6 +85,10 @@ def score_details
 
   action_auth_level :new, :instructor
   def new
+    # Clear cache since new submission exists, need to remake
+    Rails.cache.delete(["submission_ids", @assessment.id])
+    Rails.cache.delete(["submissions_to_cud", @assessment.id])
+
     @submission = @assessment.submissions.new(tweak: Tweak.new)
 
     if !params["course_user_datum_id"].nil?
@@ -141,6 +150,7 @@ def create
         @submission.save_file(params[:submission])
       end
     end
+
     flash[:success] =
       "#{ActionController::Base.helpers.pluralize(cud_ids.size, 'Submission')} Created"
     redirect_to course_assessment_submissions_path(@course, @assessment)