add more caching + performance improvements

refs #CNVS-21317

Change-Id: Id9bbb04a92abd835af69ba5ec0c21ef758a8a324
Reviewed-on: https://gerrit.instructure.com/61146
Reviewed-by: Dan Minkevitch <dan@instructure.com>
Reviewed-by: Jeremy Stanley <jeremy@instructure.com>
Product-Review: James Williams  <jamesw@instructure.com>
QA-Review: James Williams  <jamesw@instructure.com>
Tested-by: Jenkins

Author: maneframe

app/helpers/context_modules_helper.rb

@@ -54,7 +54,7 @@ def preload_can_unpublish(context, modules)
   def module_item_publishable_id(item)
     if item.nil?
       ''
-    elsif (item.content_type_class == 'wiki_page')
+    elsif (item.content_type == 'WikiPage')
       "page_id:#{item.content.id}"
     else
       (item.content && item.content.respond_to?(:published?) ? item.content.id : item.id)

app/models/content_tag.rb

@@ -24,12 +24,16 @@ def initialize( alignment )
       @alignment = alignment
     end
   end
+
+  TABLED_CONTENT_TYPES = ['Attachment', 'Assignment', 'WikiPage', 'Quizzes::Quiz', 'LearningOutcome', 'DiscussionTopic',
+    'Rubric', 'ContextExternalTool', 'LearningOutcomeGroup', 'AssessmentQuestionBank', 'LiveAssessments::Assessment', 'Lti::MessageHandler'].freeze
+  TABLELESS_CONTENT_TYPES = ['ContextModuleSubHeader', 'ExternalUrl'].freeze
+  CONTENT_TYPES = (TABLED_CONTENT_TYPES + TABLELESS_CONTENT_TYPES).freeze
+
   include Workflow
   include SearchTermHelper
   belongs_to :content, :polymorphic => true
-  validates_inclusion_of :content_type, :allow_nil => true, :in => ['Attachment', 'Assignment', 'WikiPage',
-    'ContextModuleSubHeader', 'Quizzes::Quiz', 'ExternalUrl', 'LearningOutcome', 'DiscussionTopic',
-    'Rubric', 'ContextExternalTool', 'LearningOutcomeGroup', 'AssessmentQuestionBank', 'LiveAssessments::Assessment', 'Lti::MessageHandler']
+  validates_inclusion_of :content_type, :allow_nil => true, :in => CONTENT_TYPES
   belongs_to :context, :polymorphic => true
   validates_inclusion_of :context_type, :allow_nil => true, :in => ['Course', 'LearningOutcomeGroup',
     'Assignment', 'Account', 'Quizzes::Quiz']
@@ -167,8 +171,9 @@ def scoreable?
 
   def graded?
     return true if self.content_type == 'Assignment'
-    return false unless self.content_type.constantize.column_names.include?('assignment_id') #.new.respond_to?(:assignment_id)
-    return !content.assignment_id.nil? rescue false
+    return false unless self.can_have_assignment?
+
+    return content && !content.assignment_id.nil?
   end
 
   def content_type_class
@@ -209,9 +214,7 @@ def assignment
 
   alias_method :old_content, :content
   def content
-    #self.content_type = 'Quizzes::Quiz' if self.content_type == 'Quiz'
-    klass = self.content_type.classify.constantize rescue nil
-    klass.respond_to?("tableless?") && klass.tableless? ? nil : old_content
+    TABLELESS_CONTENT_TYPES.include?(self.content_type) ? nil : old_content
   end
 
   def content_or_self

app/models/discussion_topic.rb

@@ -1028,27 +1028,29 @@ def available_for?(user, opts = {})
   #
   # Returns a boolean.
   def visible_for?(user = nil)
-    # user is the topic's author
-    return true if user == self.user
+    RequestCache.cache('discussion_visible_for', self, user) do
+      # user is the topic's author
+      return true if user == self.user
 
-    # user is an admin in the context (teacher/ta/designer) OR
-    # user is an account admin with appropriate permission
-    return true if context.grants_any_right?(user, :manage, :read_course_content)
+      # user is an admin in the context (teacher/ta/designer) OR
+      # user is an account admin with appropriate permission
+      return true if context.grants_any_right?(user, :manage, :read_course_content)
 
-    # assignment exists and isnt assigned to user (differentiated assignments)
-    if for_assignment? && !self.assignment.visible_to_user?(user)
-      return false
-    end
+      # assignment exists and isnt assigned to user (differentiated assignments)
+      if for_assignment? && !self.assignment.visible_to_user?(user)
+        return false
+      end
 
-    # topic is not published
-    if !published?
-      false
-    elsif is_announcement && unlock_at = available_from_for(user)
-    # unlock date exists and has passed
-      unlock_at < Time.now.utc
-    # everything else
-    else
-      true
+      # topic is not published
+      if !published?
+        false
+      elsif is_announcement && unlock_at = available_from_for(user)
+      # unlock date exists and has passed
+        unlock_at < Time.now.utc
+      # everything else
+      else
+        true
+      end
     end
   end
 

app/models/enrollment.rb

@@ -241,14 +241,17 @@ def update_needs_grading_count
 
 
   def self.readable_types
-    {
-      'TeacherEnrollment' => t('#enrollment.roles.teacher', "Teacher"),
-      'TaEnrollment' => t('#enrollment.roles.ta', "TA"),
-      'DesignerEnrollment' => t('#enrollment.roles.designer', "Designer"),
-      'StudentEnrollment' => t('#enrollment.roles.student', "Student"),
-      'StudentViewEnrollment' => t('#enrollment.roles.student', "Student"),
-      'ObserverEnrollment' => t('#enrollment.roles.observer', "Observer")
-    }
+    # with enough use, even translations can add up
+    RequestCache.cache('enrollment_readable_types') do
+      {
+        'TeacherEnrollment' => t('#enrollment.roles.teacher', "Teacher"),
+        'TaEnrollment' => t('#enrollment.roles.ta', "TA"),
+        'DesignerEnrollment' => t('#enrollment.roles.designer', "Designer"),
+        'StudentEnrollment' => t('#enrollment.roles.student', "Student"),
+        'StudentViewEnrollment' => t('#enrollment.roles.student', "Student"),
+        'ObserverEnrollment' => t('#enrollment.roles.observer', "Observer")
+      }
+    end
   end
 
   def self.readable_type(type)

app/models/user.rb

@@ -236,8 +236,10 @@ def page_views(options={})
   }
 
   def assignment_and_quiz_visibilities(context)
-     {assignment_ids: DifferentiableAssignment.scope_filter(context.assignments, self, context).pluck(:id),
-      quiz_ids: DifferentiableAssignment.scope_filter(context.quizzes, self, context).pluck(:id)}
+    RequestCache.cache("assignment_and_quiz_visibilities", self, context) do
+      {assignment_ids: DifferentiableAssignment.scope_filter(context.assignments, self, context).pluck(:id),
+        quiz_ids: DifferentiableAssignment.scope_filter(context.quizzes, self, context).pluck(:id)}
+    end
   end
 
   def self.order_by_sortable_name(options = {})

lib/differentiable_assignment.rb

@@ -58,10 +58,15 @@ def self.scope_filter(scope, user, context, opts={})
 
   def self.teacher_or_public_user?(user, context, opts)
     return true if opts[:is_teacher] == true
-    return true if !context.includes_user?(user)
-    permissions_implying_visibility = [:read_as_admin, :manage_grades, :manage_assignments]
-    permissions_implying_visibility << :manage_content if context.is_a?(Course)
-    context.grants_any_right?(user, *permissions_implying_visibility)
+    RequestCache.cache('teacher_or_public_user', user, context) do
+      if !context.includes_user?(user)
+        true
+      else
+        permissions_implying_visibility = [:read_as_admin, :manage_grades, :manage_assignments]
+        permissions_implying_visibility << :manage_content if context.is_a?(Course)
+        context.grants_any_right?(user, *permissions_implying_visibility)
+      end
+    end
   end
 
   def self.user_not_observer?(user, context, opts)