show temporary invitations from all shards

test plan:
 * turn on cross-shard invitations in the console
   (Setting.set('cross_shard_invitations', '1'))
 * create a user with an email address in a shard (NOT
   a site admin)
 * in an unrelated shard with open registration on,
   as an admin invite that e-mail address to a course
 * log in as the original user on the first shard; the invitation
   should show up on your dashboard
 * accepting/rejecting that invitation is *not* yet supported

Change-Id: I3b0c9657fe0dd37a737af9f4253ea8ef8b2f2b91
Reviewed-on: https://gerrit.instructure.com/14903
Tested-by: Jenkins <jenkins@instructure.com>
Reviewed-by: Jacob Fugal <jacob@instructure.com>

app/models/communication_channel.rb

@@ -359,4 +359,8 @@ class CommunicationChannel < ActiveRecord::Base
   protected :assert_path_type
     
   def self.serialization_excludes; [:confirmation_code]; end
+
+  def self.associated_shards(path)
+    [Shard.default]
+  end
 end

app/models/enrollment.rb

@@ -323,7 +323,13 @@ class Enrollment < ActiveRecord::Base
 
   def clear_email_caches
     if self.workflow_state_changed? && (self.workflow_state_was == 'invited' || self.workflow_state == 'invited')
-      self.user.communication_channels.email.unretired.each { |cc| Rails.cache.delete([cc.path, 'invited_enrollments'].cache_key)}
+      if Enrollment.cross_shard_invitations?
+        Shard.default.activate do
+          self.user.communication_channels.email.unretired.each { |cc| Rails.cache.delete([cc.path, 'all_invited_enrollments'].cache_key)}
+        end
+      else
+        self.user.communication_channels.email.unretired.each { |cc| Rails.cache.delete([cc.path, 'invited_enrollments'].cache_key)}
+      end
     end
   end
 
@@ -837,8 +843,18 @@ class Enrollment < ActiveRecord::Base
     }
   }
   def self.cached_temporary_invitations(email)
-    Rails.cache.fetch([email, 'invited_enrollments'].cache_key) do
-      Enrollment.invited.for_email(email).to_a
+    if Enrollment.cross_shard_invitations?
+      Shard.default.activate do
+        invitations = Rails.cache.fetch([email, 'all_invited_enrollments'].cache_key) do
+          Shard.with_each_shard(CommunicationChannel.associated_shards(email)) do
+            Enrollment.invited.for_email(email).to_a
+          end
+        end
+      end
+    else
+      Rails.cache.fetch([email, 'invited_enrollments'].cache_key) do
+        Enrollment.invited.for_email(email).to_a
+      end
     end
   end
 
@@ -959,4 +975,8 @@ class Enrollment < ActiveRecord::Base
     course.conclude_at ||
     course.enrollment_term && course.enrollment_term.end_at
   end
+
+  def self.cross_shard_invitations?
+    false
+  end
 end

spec/models/enrollment_spec.rb

@@ -1141,29 +1141,92 @@ describe Enrollment do
     end
   end
 
-  it "should uncache temporary user invitations when state changes" do
-    enable_cache do
-      course(:active_all => 1)
-      user
-      @user.update_attribute(:workflow_state, 'creation_pending')
-      @user.communication_channels.create!(:path => 'jt@instructure.com')
-      @enrollment = @course.enroll_user(@user)
-      Enrollment.cached_temporary_invitations('jt@instructure.com').length.should == 1
-      @enrollment.accept
-      Enrollment.cached_temporary_invitations('jt@instructure.com').should == []
+  describe "cached_temporary_invitations" do
+    it "should uncache temporary user invitations when state changes" do
+      enable_cache do
+        course(:active_all => 1)
+        user
+        @user.update_attribute(:workflow_state, 'creation_pending')
+        @user.communication_channels.create!(:path => 'jt@instructure.com')
+        @enrollment = @course.enroll_user(@user)
+        Enrollment.cached_temporary_invitations('jt@instructure.com').length.should == 1
+        @enrollment.accept
+        Enrollment.cached_temporary_invitations('jt@instructure.com').should == []
+      end
     end
-  end
 
-  it "should uncache user enrollments when rejected" do
-    enable_cache do
-      course_with_student(:active_course => 1)
-      User.update_all({:updated_at => 1.year.ago}, :id => @user.id)
-      @user.reload
-      @user.cached_current_enrollments.should == [@enrollment]
-      @enrollment.reject!
-      # have to get the new updated_at
-      @user.reload
-      @user.cached_current_enrollments(true).should == []
+    it "should uncache user enrollments when rejected" do
+      enable_cache do
+        course_with_student(:active_course => 1)
+        User.update_all({:updated_at => 1.year.ago}, :id => @user.id)
+        @user.reload
+        @user.cached_current_enrollments.should == [@enrollment]
+        @enrollment.reject!
+        # have to get the new updated_at
+        @user.reload
+        @user.cached_current_enrollments(true).should == []
+      end
+    end
+
+    context "sharding" do
+      it_should_behave_like "sharding"
+
+      before do
+        Enrollment.stubs(:cross_shard_invitations?).returns(true)
+        course(:active_all => 1)
+        user
+        @user.update_attribute(:workflow_state, 'creation_pending')
+        @user.communication_channels.create!(:path => 'jt@instructure.com')
+        @enrollment1 = @course.enroll_user(@user)
+        @shard1.activate do
+          account = Account.create!
+          course(:active_all => 1, :account => account)
+          user
+          @user.update_attribute(:workflow_state, 'creation_pending')
+          @user.communication_channels.create!(:path => 'jt@instructure.com')
+          @enrollment2 = @course.enroll_user(@user)
+        end
+
+        pending "working CommunicationChannel.associated_shards" unless CommunicationChannel.associated_shards('jt@instructure.com').length == 2
+      end
+
+      it "should include invitations from other shards" do
+        Enrollment.cached_temporary_invitations('jt@instructure.com').sort_by(&:global_id).should == [@enrollment1, @enrollment2].sort_by(&:global_id)
+        @shard1.activate do
+          Enrollment.cached_temporary_invitations('jt@instructure.com').sort_by(&:global_id).should == [@enrollment1, @enrollment2].sort_by(&:global_id)
+        end
+        @shard2.activate do
+          Enrollment.cached_temporary_invitations('jt@instructure.com').sort_by(&:global_id).should == [@enrollment1, @enrollment2].sort_by(&:global_id)
+        end
+      end
+
+      it "should have a single cache for all shards" do
+        enable_cache do
+          @shard2.activate do
+            Enrollment.cached_temporary_invitations('jt@instructure.com').sort_by(&:global_id).should == [@enrollment1, @enrollment2].sort_by(&:global_id)
+          end
+          Shard.expects(:with_each_shard).never
+          @shard1.activate do
+            Enrollment.cached_temporary_invitations('jt@instructure.com').sort_by(&:global_id).should == [@enrollment1, @enrollment2].sort_by(&:global_id)
+          end
+          Enrollment.cached_temporary_invitations('jt@instructure.com').sort_by(&:global_id).should == [@enrollment1, @enrollment2].sort_by(&:global_id)
+        end
+      end
+
+      it "should invalidate the cache from any shard" do
+        enable_cache do
+          @shard2.activate do
+            Enrollment.cached_temporary_invitations('jt@instructure.com').sort_by(&:global_id).should == [@enrollment1, @enrollment2].sort_by(&:global_id)
+            @enrollment2.reject!
+          end
+          @shard1.activate do
+            Enrollment.cached_temporary_invitations('jt@instructure.com').should == [@enrollment1]
+            @enrollment1.reject!
+          end
+          Enrollment.cached_temporary_invitations('jt@instructure.com').should == []
+        end
+
+      end
     end
   end