Optimize followed hashtag ids query, add test for hashtags in home timeline

Signed-off-by: mkljczk <git@mkljczk.pl>

changelog.d/follow-hashtags.change

@@ -0,0 +1 @@
+Optimize followed hashtag ids query, add test for hashtags in home timeline

lib/pleroma/web/activity_pub/activity_pub.ex

@@ -928,15 +928,9 @@ defmodule Pleroma.Web.ActivityPub.ActivityPub do
   # that reference a hashtag that the user follows
   # Firstly, two fallbacks in case there's no hashtag constraint, or the user doesn't
   # follow any
-  defp restrict_recipients_or_hashtags(query, recipients, user, nil) do
-    restrict_recipients(query, recipients, user)
-  end
+  defp restrict_recipients_or_hashtags(query, recipients, user, true) do
+    followed_hashtag_ids = Ecto.assoc(user, :followed_hashtags) |> select([h], h.id)
 
-  defp restrict_recipients_or_hashtags(query, recipients, user, []) do
-    restrict_recipients(query, recipients, user)
-  end
-
-  defp restrict_recipients_or_hashtags(query, recipients, _user, hashtag_ids) do
     from([activity, object] in query)
     |> join(:left, [activity, object], hto in "hashtags_objects",
       on: hto.object_id == object.id,
@@ -944,11 +938,16 @@ defmodule Pleroma.Web.ActivityPub.ActivityPub do
     )
     |> where(
       [activity, object, hto: hto],
-      (hto.hashtag_id in ^hashtag_ids and ^Constants.as_public() in activity.recipients) or
+      (hto.hashtag_id in subquery(followed_hashtag_ids) and
+         ^Constants.as_public() in activity.recipients) or
         fragment("? && ?", ^recipients, activity.recipients)
     )
   end
 
+  defp restrict_recipients_or_hashtags(query, recipients, user, _) do
+    restrict_recipients(query, recipients, user)
+  end
+
   defp restrict_local(query, %{local_only: true}) do
     from(activity in query, where: activity.local == true)
   end
@@ -1439,7 +1438,7 @@ defmodule Pleroma.Web.ActivityPub.ActivityPub do
       |> maybe_preload_report_notes(opts)
       |> maybe_set_thread_muted_field(opts)
       |> maybe_order(opts)
-      |> restrict_recipients_or_hashtags(recipients, opts[:user], opts[:followed_hashtags])
+      |> restrict_recipients_or_hashtags(recipients, opts[:user], opts[:with_followed_hashtags])
       |> restrict_replies(opts)
       |> restrict_since(opts)
       |> restrict_local(opts)

lib/pleroma/web/mastodon_api/controllers/timeline_controller.ex

@@ -40,11 +40,6 @@ defmodule Pleroma.Web.MastodonAPI.TimelineController do
 
   # GET /api/v1/timelines/home
   def home(%{assigns: %{user: user}} = conn, params) do
-    followed_hashtags =
-      user
-      |> User.followed_hashtags()
-      |> Enum.map(& &1.id)
-
     params =
       params
       |> Map.put(:type, ["Create", "Announce"])
@@ -54,7 +49,7 @@ defmodule Pleroma.Web.MastodonAPI.TimelineController do
       |> Map.put(:announce_filtering_user, user)
       |> Map.put(:user, user)
       |> Map.put(:local_only, params[:local])
-      |> Map.put(:followed_hashtags, followed_hashtags)
+      |> Map.put(:with_followed_hashtags, true)
       |> Map.delete(:local)
 
     activities =

test/pleroma/web/mastodon_api/controllers/timeline_controller_test.exs

@@ -149,6 +149,31 @@ defmodule Pleroma.Web.MastodonAPI.TimelineControllerTest do
              |> get("/api/v1/timelines/home?remote=true&local=true")
              |> json_response_and_validate_schema(200) == []
     end
+
+    test "includes followed hashtags", %{conn: conn, user: user} do
+      hashtag = insert(:hashtag, %{name: "tenshi"})
+      other_user = insert(:user)
+      {:ok, user} = User.follow_hashtag(user, hashtag)
+
+      {:ok, _} = CommonAPI.post(other_user, %{status: "hey #tenshi"})
+      {:ok, _} = CommonAPI.post(other_user, %{status: "hey #anotherhashtag"})
+
+      result =
+        conn
+        |> assign(:user, user)
+        |> get("/api/v1/timelines/home")
+        |> json_response_and_validate_schema(200)
+
+      assert [
+               %{
+                 "tags" => [
+                   %{
+                     "name" => "tenshi"
+                   }
+                 ]
+               }
+             ] = result
+    end
   end
 
   describe "public" do