get assignments and submissions from all shards

fixes CNVS-4959

(note that this does not cover the cross-shard links
from these assignments working correctly; that is a
separate issue)

test plan:
 * enroll a user in courses in multiple shards
 * assignments from all courses should show up in
   /assignments regardless of current shard

Change-Id: Ic46711a31ddc573f124cad3ed2bc5abefd4646a9
Reviewed-on: https://gerrit.instructure.com/19234
Tested-by: Jenkins <jenkins@instructure.com>
QA-Review: Clare Strong <clare@instructure.com>
Reviewed-by: Jacob Fugal <jacob@instructure.com>
Product-Review: Cody Cutrer <cody@instructure.com>

app/controllers/application_controller.rb

@@ -446,8 +446,8 @@ class ApplicationController < ActionController::Base
       # we already know the user can read these courses and groups, so skip
       # the grants_right? check to avoid querying for the various memberships
       # again.
-      courses = @context.current_enrollments.select { |e| e.state_based_on_date == :active }.map(&:course).uniq
-      groups = include_groups ? @context.current_groups : []
+      courses = @context.current_enrollments.with_each_shard.select { |e| e.state_based_on_date == :active }.map(&:course).uniq
+      groups = include_groups ? @context.current_groups.with_each_shard : []
       if only_contexts.present?
         # find only those courses and groups passed in the only_contexts
         # parameter, but still scoped by user so we know they have rights to
@@ -455,7 +455,7 @@ class ApplicationController < ActionController::Base
         course_ids = only_contexts.select { |c| c.first == "Course" }.map(&:last)
         courses = course_ids.empty? ? [] : courses.select { |c| course_ids.include?(c.id) }
         group_ids = only_contexts.select { |c| c.first == "Group" }.map(&:last)
-        groups = group_ids.empty? ? [] : groups.find_all_by_id(group_ids) if include_groups
+        groups = group_ids.empty? ? [] : groups.select { |g| group_ids.include?(g.id) } if include_groups
       end
       @contexts.concat courses
       @contexts.concat groups
@@ -509,15 +509,23 @@ class ApplicationController < ActionController::Base
       @groups = @courses.first.assignment_groups.active.includes(:active_assignments)
       @assignments = @groups.map(&:active_assignments).flatten
     else
-      @groups = AssignmentGroup.for_context_codes(@context_codes).active
-      @assignments = Assignment.active.for_course(@courses.map(&:id))
+      assignments_and_groups = Shard.partition_by_shard(@courses) do |courses|
+        [[Assignment.active.for_course(courses).all,
+         AssignmentGroup.active.for_course(courses).order(:position).all]]
+      end
+      @assignments = assignments_and_groups.map(&:first).flatten
+      @groups = assignments_and_groups.map(&:last).flatten
     end
     @assignment_groups = @groups
 
     @courses.each { |course| log_course(course) }
 
-    @submissions = @current_user.try(:submissions).to_a
-    @submissions.each{ |s| s.mute if s.muted_assignment? }
+    if @current_user
+      @submissions = @current_user.submissions.with_each_shard
+      @submissions.each{ |s| s.mute if s.muted_assignment? }
+    else
+      @submissions = []
+    end
 
     @assignments.map! {|a| a.overridden_for(@current_user)}
     sorted = SortsAssignments.by_due_date({

app/models/assignment_group.rb

@@ -126,6 +126,7 @@ class AssignmentGroup < ActiveRecord::Base
   scope :active, where("assignment_groups.workflow_state<>'deleted'")
   scope :before, lambda { |date| where("assignment_groups.created_at<?", date) }
   scope :for_context_codes, lambda { |codes| active.where(:context_code => codes).order(:position) }
+  scope :for_course, lambda { |course| where(:context_id => course, :context_type => 'Course') }
 
   def group_weight_changed
     @group_weight_changed = self.group_weight_changed?

app/models/course.rb

@@ -864,20 +864,25 @@ class Course < ActiveRecord::Base
 
   def self.require_assignment_groups(contexts)
     courses = contexts.select{|c| c.is_a?(Course) }
-    hash = {}
-    courses.each{|c| hash[c.id] = {:found => false, :course => c} }
-    groups = AssignmentGroup.select("id, context_id, context_type").where(:context_type => "Course", :context_id => courses)
-    groups.each{|c| hash[c.context_id][:found] = true }
-    hash.select{|id, obj| !obj[:found] }.each{|id, obj| obj[:course].require_assignment_group rescue nil }
+    groups = Shard.partition_by_shard(courses) do |shard_courses|
+      AssignmentGroup.select("id, context_id, context_type").where(:context_type => "Course", :context_id => shard_courses)
+    end.index_by(&:context_id)
+    courses.each do |course|
+      if !groups[course.id]
+        course.require_assignment_group rescue nil
+      end
+    end
   end
 
   def require_assignment_group
-    has_group = Rails.cache.read(['has_assignment_group', self].cache_key)
-    return if has_group && Rails.env.production?
-    if self.assignment_groups.active.empty?
-      self.assignment_groups.create(:name => t('#assignment_group.default_name', "Assignments"))
+    shard.activate do
+      has_group = Rails.cache.read(['has_assignment_group', self].cache_key)
+      return if has_group && Rails.env.production?
+      if self.assignment_groups.active.empty?
+        self.assignment_groups.create(:name => t('#assignment_group.default_name', "Assignments"))
+      end
+      Rails.cache.write(['has_assignment_group', self].cache_key, true)
     end
-    Rails.cache.write(['has_assignment_group', self].cache_key, true)
   end
 
   def self.create_unique(uuid=nil, account_id=nil, root_account_id=nil)

spec/controllers/assignments_controller_spec.rb

@@ -16,18 +16,20 @@
 # with this program. If not, see <http://www.gnu.org/licenses/>.
 #
 
-require File.expand_path(File.dirname(__FILE__) + '/../spec_helper')
+require File.expand_path(File.dirname(__FILE__) + '/../sharding_spec_helper')
 
 describe AssignmentsController do
   # it "should use AssignmentsController" do
   #   controller.should be_an_instance_of(AssignmentsController)
   # end
 
-  def course_assignment
-    @group = @course.assignment_groups.create(:name => "some group")
-    @assignment = @course.assignments.create(:title => "some assignment", :assignment_group => @group)
+  def course_assignment(course = nil)
+    course ||= @course
+    @group = course.assignment_groups.create(:name => "some group")
+    @assignment = course.assignments.create(:title => "some assignment", :assignment_group => @group)
     @assignment.assignment_group.should eql(@group)
     @group.assignments.should be_include(@assignment)
+    @assignment
   end
 
   describe "GET 'index'" do
@@ -81,6 +83,28 @@ describe AssignmentsController do
       assigns[:assignment_groups].should_not be_empty
       assigns[:assignment_groups][0].name.should eql("Assignments")
     end
+
+    context "sharding" do
+      specs_require_sharding
+
+      it "should show assignments for all shards" do
+        course_with_student_logged_in(:active_all => true)
+        @assignment1 = course_assignment
+
+        @shard2.activate do
+          account = Account.create!
+          course2 = account.courses.create!
+          course2.offer!
+          @assignment2 = course_assignment(course2)
+          course2.enroll_student(@user).accept!
+        end
+
+        get 'index'
+        assigns[:assignments].length.should == 2
+        assigns[:assignments].should be_include(@assignment1)
+        assigns[:assignments].should be_include(@assignment2)
+      end
+    end
   end
   
   describe "GET 'show'" do