From 385372e3848eb797878023a650a7ef5e651e6410 Mon Sep 17 00:00:00 2001
From: Guo Xiang Tan <tgx_world@hotmail.com>
Date: Mon, 20 Nov 2017 11:49:09 +0800
Subject: [PATCH] Revert "PERF: Reduce number of topics to filter while
 querying for unread."

This reverts commit c06b782cabbde812350622ee4728dc61dc524d2f.
---
 lib/topic_query.rb                  | 20 ++------------------
 spec/components/topic_query_spec.rb | 22 ++++------------------
 2 files changed, 6 insertions(+), 36 deletions(-)

diff --git a/lib/topic_query.rb b/lib/topic_query.rb
index 2da99393a02..14aaaa8bbc7 100644
--- a/lib/topic_query.rb
+++ b/lib/topic_query.rb
@@ -288,9 +288,8 @@ class TopicQuery
 
     list
       .where("tu.last_read_post_number < topics.#{col_name}")
-      .where("tu.notification_level >= :tracking",
-        tracking: TopicUser.notification_levels[:tracking]
-      )
+      .where("COALESCE(tu.notification_level, :regular) >= :tracking",
+               regular: TopicUser.notification_levels[:regular], tracking: TopicUser.notification_levels[:tracking])
   end
 
   def prioritize_pinned_topics(topics, options)
@@ -370,10 +369,6 @@ class TopicQuery
     result
   end
 
-  def unread_results_redis_key
-    "last_unread_result_bumped_at:#{@user.id}"
-  end
-
   def unread_results(options = {})
     result = TopicQuery.unread_filter(
         default_results(options.reverse_merge(unordered: true)),
@@ -385,17 +380,6 @@ class TopicQuery
       result = filter_callback.call(:unread, result, @user, options)
     end
 
-    if !(last_bumped_at = $redis.get(unread_results_redis_key))
-      last_bumped_at = result.unscope(:limit, :order).order(:bumped_at).first&.bumped_at
-
-      $redis.setex(
-        unread_results_redis_key,
-        1.hour.to_i,
-        (last_bumped_at || Time.zone.now).to_s
-      )
-    end
-
-    result = result.where("topics.bumped_at >= ?", last_bumped_at) if last_bumped_at
     suggested_ordering(result, options)
   end
 
diff --git a/spec/components/topic_query_spec.rb b/spec/components/topic_query_spec.rb
index d2a1c28ca32..be119f53099 100644
--- a/spec/components/topic_query_spec.rb
+++ b/spec/components/topic_query_spec.rb
@@ -443,9 +443,6 @@ describe TopicQuery do
   end
 
   context 'unread / read topics' do
-    after do
-      $redis.flushall
-    end
 
     context 'with no data' do
       it "has no unread topics" do
@@ -487,15 +484,10 @@ describe TopicQuery do
 
       context 'list_unread' do
         it 'lists topics correctly' do
-          freeze_time do
-            new_topic = Fabricate(:post, user: creator).topic
+          new_topic = Fabricate(:post, user: creator).topic
 
-            expect(topic_query.list_unread.topics).to eq([])
-            expect(topic_query.list_read.topics).to match_array([fully_read, partially_read])
-
-            expect($redis.get(topic_query.unread_results_redis_key))
-              .to eq(Time.zone.now.to_s)
-          end
+          expect(topic_query.list_unread.topics).to eq([])
+          expect(topic_query.list_read.topics).to match_array([fully_read, partially_read])
         end
       end
 
@@ -503,16 +495,10 @@ describe TopicQuery do
         before do
           user.user_option.auto_track_topics_after_msecs = 0
           user.user_option.save
-          partially_read.update!(bumped_at: 2.days.ago)
         end
 
         it 'only contains the partially read topic' do
-          freeze_time do
-            expect(topic_query.list_unread.topics).to eq([partially_read])
-
-            expect($redis.get(topic_query.unread_results_redis_key))
-              .to eq(partially_read.bumped_at.to_s)
-          end
+          expect(topic_query.list_unread.topics).to eq([partially_read])
         end
       end