Fix #2619 - When redis feed is empty, fall back to database (#3721)

* Fix #2619 - When redis feed is empty, fall back to database

* Use redis value to return feed from database only while RegenerationWorker
hasn't finished running

* Fix specs

* Replace usage of reject!

1 files changed, 15 insertions, 2 deletions

diff --git a/app/models/feed.rb b/app/models/feed.rb
index 3cbc160a0..5125e51ff 100644
--- a/app/models/feed.rb
+++ b/app/models/feed.rb
@@ -7,15 +7,28 @@ class Feed
   end
 
   def get(limit, max_id = nil, since_id = nil)
+    if redis.exists("account:#{@account.id}:regeneration")
+      from_database(limit, max_id, since_id)
+    else
+      from_redis(limit, max_id, since_id)
+    end
+  end
+
+  private
+
+  def from_redis(limit, max_id, since_id)
     max_id     = '+inf' if max_id.blank?
     since_id   = '-inf' if since_id.blank?
     unhydrated = redis.zrevrangebyscore(key, "(#{max_id}", "(#{since_id}", limit: [0, limit], with_scores: true).map(&:last).map(&:to_i)
     status_map = Status.where(id: unhydrated).cache_ids.map { |s| [s.id, s] }.to_h
-
     unhydrated.map { |id| status_map[id] }.compact
   end
 
-  private
+  def from_database(limit, max_id, since_id)
+    Status.as_home_timeline(@account)
+          .paginate_by_max_id(limit, max_id, since_id)
+          .reject { |status| FeedManager.instance.filter?(:home, status, @account.id) }
+  end
 
   def key
     FeedManager.instance.key(@type, @account.id)