Improve counter caches on Status and Account (#7644)

Do not touch statuses_count on accounts table when mass-destroying
statuses to reduce load when removing accounts, same for
reblogs_count and favourites_count

Do not count statuses with direct visibility in statuses_count

Fix #828

1 files changed, 24 insertions, 1 deletions

diff --git a/app/models/favourite.rb b/app/models/favourite.rb
index c998a67eb..0fce82f6f 100644
--- a/app/models/favourite.rb
+++ b/app/models/favourite.rb
@@ -16,7 +16,7 @@ class Favourite < ApplicationRecord
   update_index('statuses#status', :status) if Chewy.enabled?
 
   belongs_to :account, inverse_of: :favourites
-  belongs_to :status,  inverse_of: :favourites, counter_cache: true
+  belongs_to :status,  inverse_of: :favourites
 
   has_one :notification, as: :activity, dependent: :destroy
 
@@ -25,4 +25,27 @@ class Favourite < ApplicationRecord
   before_validation do
     self.status = status.reblog if status&.reblog?
   end
+
+  after_create :increment_cache_counters
+  after_destroy :decrement_cache_counters
+
+  private
+
+  def increment_cache_counters
+    if association(:status).loaded?
+      status.update_attribute(:favourites_count, status.favourites_count + 1)
+    else
+      Status.where(id: status_id).update_all('favourites_count = COALESCE(favourites_count, 0) + 1')
+    end
+  end
+
+  def decrement_cache_counters
+    return if association(:status).loaded? && (status.marked_for_destruction? || status.marked_for_mass_destruction?)
+
+    if association(:status).loaded?
+      status.update_attribute(:favourites_count, [status.favourites_count - 1, 0].max)
+    else
+      Status.where(id: status_id).update_all('favourites_count = GREATEST(COALESCE(favourites_count, 0) - 1, 0)')
+    end
+  end
 end