Don't fetch anything except ap_id for follower / following

collections.

Should speed up the queries because ecto doesn't have to parse the json.

lib/pleroma/user.ex

@@ -278,24 +278,30 @@ def get_or_fetch_by_nickname(nickname) do
     end
   end
 
-  def get_followers(%User{id: id, follower_address: follower_address}) do
+  def get_followers_query(%User{id: id, follower_address: follower_address}) do
-    q =
     from(
       u in User,
       where: fragment("? <@ ?", ^[follower_address], u.following),
       where: u.id != ^id
     )
+  end
+
+  def get_followers(user) do
+    q = get_followers_query(user)
 
     {:ok, Repo.all(q)}
   end
 
-  def get_friends(%User{id: id, following: following}) do
+  def get_friends_query(%User{id: id, following: following}) do
-    q =
     from(
       u in User,
       where: u.follower_address in ^following,
       where: u.id != ^id
     )
+  end
+
+  def get_friends(user) do
+    q = get_friends_query(user)
 
     {:ok, Repo.all(q)}
   end

lib/pleroma/web/activity_pub/views/user_view.ex

@@ -3,9 +3,11 @@ defmodule Pleroma.Web.ActivityPub.UserView do
   alias Pleroma.Web.Salmon
   alias Pleroma.Web.WebFinger
   alias Pleroma.User
+  alias Pleroma.Repo
   alias Pleroma.Web.ActivityPub.ActivityPub
   alias Pleroma.Web.ActivityPub.Transmogrifier
   alias Pleroma.Web.ActivityPub.Utils
+  import Ecto.Query
 
   def render("user.json", %{user: user}) do
     {:ok, user} = WebFinger.ensure_keys_present(user)
@@ -45,10 +47,11 @@ def render("user.json", %{user: user}) do
     |> Map.merge(Utils.make_json_ld_header())
   end
 
-  def collection(collection, iri, page) do
+  def collection(collection, iri, page, total \\ nil) do
     offset = (page - 1) * 10
     items = Enum.slice(collection, offset, 10)
     items = Enum.map(items, fn user -> user.ap_id end)
+    total = total || length(collection)
 
     map = %{
       "id" => "#{iri}?page=#{page}",
@@ -64,14 +67,18 @@ def collection(collection, iri, page) do
   end
 
   def render("following.json", %{user: user, page: page}) do
-    {:ok, following} = User.get_friends(user)
+    query = User.get_friends_query(user)
+    query = from(user in query, select: [:ap_id])
+    following = Repo.all(query)
 
     collection(following, "#{user.ap_id}/following", page)
     |> Map.merge(Utils.make_json_ld_header())
   end
 
   def render("following.json", %{user: user}) do
-    {:ok, following} = User.get_friends(user)
+    query = User.get_friends_query(user)
+    query = from(user in query, select: [:ap_id])
+    following = Repo.all(query)
 
     %{
       "id" => "#{user.ap_id}/following",
@@ -83,14 +90,18 @@ def render("following.json", %{user: user}) do
   end
 
   def render("followers.json", %{user: user, page: page}) do
-    {:ok, followers} = User.get_followers(user)
+    query = User.get_followers_query(user)
+    query = from(user in query, select: [:ap_id])
+    followers = Repo.all(query)
 
     collection(followers, "#{user.ap_id}/followers", page)
     |> Map.merge(Utils.make_json_ld_header())
   end
 
   def render("followers.json", %{user: user}) do
-    {:ok, followers} = User.get_followers(user)
+    query = User.get_followers_query(user)
+    query = from(user in query, select: [:ap_id])
+    followers = Repo.all(query)
 
     %{
       "id" => "#{user.ap_id}/followers",

test/web/activity_pub/activity_pub_controller_test.exs

@@ -49,4 +49,87 @@ test "it inserts an incoming activity into the database", %{conn: conn} do
       assert Activity.get_by_ap_id(data["id"])
     end
   end
+
+  describe "/users/:nickname/followers" do
+    test "it returns the followers in a collection", %{conn: conn} do
+      user = insert(:user)
+      user_two = insert(:user)
+      User.follow(user, user_two)
+
+      result =
+        conn
+        |> get("/users/#{user_two.nickname}/followers")
+        |> json_response(200)
+
+      assert result["first"]["orderedItems"] == [user.ap_id]
+    end
+
+    test "it works for more than 10 users", %{conn: conn} do
+      user = insert(:user)
+
+      Enum.each(1..15, fn _ ->
+        other_user = insert(:user)
+        User.follow(other_user, user)
+      end)
+
+      result =
+        conn
+        |> get("/users/#{user.nickname}/followers")
+        |> json_response(200)
+
+      assert length(result["first"]["orderedItems"]) == 10
+      assert result["first"]["totalItems"] == 15
+      assert result["totalItems"] == 15
+
+      result =
+        conn
+        |> get("/users/#{user.nickname}/followers?page=2")
+        |> json_response(200)
+
+      assert length(result["orderedItems"]) == 5
+      assert result["totalItems"] == 15
+    end
+  end
+
+  describe "/users/:nickname/following" do
+    test "it returns the following in a collection", %{conn: conn} do
+      user = insert(:user)
+      user_two = insert(:user)
+      User.follow(user, user_two)
+
+      result =
+        conn
+        |> get("/users/#{user.nickname}/following")
+        |> json_response(200)
+
+      assert result["first"]["orderedItems"] == [user_two.ap_id]
+    end
+
+    test "it works for more than 10 users", %{conn: conn} do
+      user = insert(:user)
+
+      Enum.each(1..15, fn _ ->
+        user = Repo.get(User, user.id)
+        other_user = insert(:user)
+        User.follow(user, other_user)
+      end)
+
+      result =
+        conn
+        |> get("/users/#{user.nickname}/following")
+        |> json_response(200)
+
+      assert length(result["first"]["orderedItems"]) == 10
+      assert result["first"]["totalItems"] == 15
+      assert result["totalItems"] == 15
+
+      result =
+        conn
+        |> get("/users/#{user.nickname}/following?page=2")
+        |> json_response(200)
+
+      assert length(result["orderedItems"]) == 5
+      assert result["totalItems"] == 15
+    end
+  end
 end