Introduce ApplicationController#cache_collection_paginated_by_id (#14677)

* Replace incorrect use of distinct with group

Some uses of ActiveRecord::QueryMethods#distinct pass field names but they
are incorrect for the current version of Rails.

ActiveRecord::QueryMethods#group provides the expected behavior and
benefits performance. See commit 6da24aad4cafdef8d8a2c92bac2002a5fc2fe9c8.

* Introduce ApplicationController#cache_collection_paginated_by_id

ApplicationController#cache_collection_paginated_by_id fuses
ApplicationController#cache_collection and Paginable.paginate_by_id.

An advantage of this method is that it prevents from modifying scope which
Paginable.paginate_by_id may provide.
ApplicationController#cache_collection always return an array and there
is no possibility of the scope modification. It is also clear for a
programmer, considering the implication of "cache".

This method can also emit more efficient queries by using
Cacheable.cache_ids before calling Paginable.paginate_by_id.

1 files changed, 8 insertions, 4 deletions

diff --git a/app/controllers/accounts_controller.rb b/app/controllers/accounts_controller.rb
index db77b628c..d97d88fd9 100644
--- a/app/controllers/accounts_controller.rb
+++ b/app/controllers/accounts_controller.rb
@@ -28,8 +28,7 @@ class AccountsController < ApplicationController
         end
 
         @pinned_statuses = cache_collection(@account.pinned_statuses, Status) if show_pinned_statuses?
-        @statuses        = filtered_status_page
-        @statuses        = cache_collection(@statuses, Status)
+        @statuses        = cached_filtered_status_page
         @rss_url         = rss_url
 
         unless @statuses.empty?
@@ -142,8 +141,13 @@ class AccountsController < ApplicationController
     request.path.split('.').first.ends_with?(Addressable::URI.parse("/tagged/#{params[:tag]}").normalize)
   end
 
-  def filtered_status_page
-    filtered_statuses.paginate_by_id(PAGE_SIZE, params_slice(:max_id, :min_id, :since_id))
+  def cached_filtered_status_page
+    cache_collection_paginated_by_id(
+      filtered_statuses,
+      Status,
+      PAGE_SIZE,
+      params_slice(:max_id, :min_id, :since_id)
+    )
   end
 
   def params_slice(*keys)