refactor(user): follow count move to table

Author: mydearxym

lib/groupher_server/accounts/delegates/fans.ex

@@ -35,8 +35,8 @@ defmodule GroupherServer.Accounts.Delegate.Fans do
           following_id: target_user.id
         })
       )
-      |> Multi.run(:update_user_meta, fn _, _ ->
-        update_follow_meta(target_user, user_id, :add)
+      |> Multi.run(:update_user_follow_info, fn _, _ ->
+        update_user_follow_info(target_user, user_id, :add)
       end)
       |> Multi.run(:add_achievement, fn _, _ ->
         Accounts.achieve(%User{id: target_user.id}, :inc, :follow)
@@ -63,8 +63,8 @@ defmodule GroupherServer.Accounts.Delegate.Fans do
       |> Multi.run(:delete_following, fn _, _ ->
         ORM.findby_delete!(UserFollowing, %{user_id: user_id, following_id: target_user.id})
       end)
-      |> Multi.run(:update_user_meta, fn _, _ ->
-        update_follow_meta(target_user, user_id, :remove)
+      |> Multi.run(:update_user_follow_info, fn _, _ ->
+        update_user_follow_info(target_user, user_id, :remove)
       end)
       |> Multi.run(:minus_achievement, fn _, _ ->
         Accounts.achieve(%User{id: target_user.id}, :dec, :follow)
@@ -78,31 +78,35 @@ defmodule GroupherServer.Accounts.Delegate.Fans do
   end
 
   # update follow in user meta
-  defp update_follow_meta(%User{} = target_user, user_id, opt) do
+  defp update_user_follow_info(%User{} = target_user, user_id, opt) do
     with {:ok, user} <- ORM.find(User, user_id) do
       target_user_meta = ensure(target_user.meta, @default_user_meta)
       user_meta = ensure(user.meta, @default_user_meta)
 
+      follower_user_ids =
+        case opt do
+          :add -> (target_user_meta.follower_user_ids ++ [user_id]) |> Enum.uniq()
+          :remove -> (target_user_meta.follower_user_ids -- [user_id]) |> Enum.uniq()
+        end
+
+      following_user_ids =
+        case opt do
+          :add -> (user_meta.following_user_ids ++ [target_user.id]) |> Enum.uniq()
+          :remove -> (user_meta.following_user_ids -- [target_user.id]) |> Enum.uniq()
+        end
+
       Multi.new()
       |> Multi.run(:update_follower_meta, fn _, _ ->
-        follower_user_ids =
-          case opt do
-            :add -> target_user_meta.follower_user_ids ++ [user_id]
-            :remove -> target_user_meta.follower_user_ids -- [user_id]
-          end
-
+        followers_count = length(follower_user_ids)
         meta = Map.merge(target_user_meta, %{follower_user_ids: follower_user_ids})
-        ORM.update_meta(target_user, meta)
+
+        ORM.update_meta(target_user, meta, changes: %{followers_count: followers_count})
       end)
       |> Multi.run(:update_following_meta, fn _, _ ->
-        following_user_ids =
-          case opt do
-            :add -> user_meta.following_user_ids ++ [target_user.id]
-            :remove -> user_meta.following_user_ids -- [target_user.id]
-          end
-
+        followings_count = length(following_user_ids)
         meta = Map.merge(user_meta, %{following_user_ids: following_user_ids})
-        ORM.update_meta(user, meta)
+
+        ORM.update_meta(user, meta, changes: %{followings_count: followings_count})
       end)
       |> Repo.transaction()
       |> result()

lib/groupher_server/accounts/helper/loader.ex

@@ -7,8 +7,6 @@ defmodule GroupherServer.Accounts.Helper.Loader do
   alias Helper.QueryBuilder
   alias GroupherServer.{Accounts, CMS, Repo}
 
-  alias Accounts.{UserFollower, UserFollowing}
-
   def data, do: Dataloader.Ecto.new(Repo, query: &query/2)
 
   def query({"communities_subscribers", CMS.CommunitySubscriber}, %{count: _}) do
@@ -24,23 +22,6 @@ defmodule GroupherServer.Accounts.Helper.Loader do
     |> select([u, c], c)
   end
 
-  # TODO: fix later, this is not working
-  def query({"users_followers", UserFollower}, %{count: _}) do
-    UserFollower
-    |> group_by([f], f.user_id)
-    |> select([f], count(f.follower_id))
-  end
-
-  def query({"users_followings", UserFollowing}, %{count: _}) do
-    UserFollowing
-    |> group_by([f], f.user_id)
-    |> select([f], count(f.id))
-  end
-
-  def query({"users_followers", UserFollower}, %{viewer_did: _, cur_user: cur_user}) do
-    UserFollower |> where([f], f.follower_id == ^cur_user.id)
-  end
-
   def query(queryable, _args), do: queryable
 
   defp count_contents(queryable) do

lib/groupher_server/accounts/user.ex

@@ -68,6 +68,9 @@ defmodule GroupherServer.Accounts.User do
     # Ta 关注了你
     field(:viewer_been_followed, :boolean, default: false, virtual: true)
 
+    field(:followings_count, :integer, default: 0)
+    field(:followers_count, :integer, default: 0)
+
     embeds_one(:meta, Embeds.UserMeta, on_replace: :update)
     embeds_one(:contributes, Embeds.UserContribute, on_replace: :update)
 

lib/groupher_server_web/schema/account/account_types.ex

@@ -93,20 +93,10 @@ defmodule GroupherServerWeb.Schema.Account.Types do
     end
 
     @desc "get follower users count"
-    field :followers_count, :integer do
-      arg(:count, :count_type, default_value: :count)
-
-      resolve(dataloader(Accounts, :followers))
-      middleware(M.ConvertToInt)
-    end
+    field(:followers_count, :integer)
 
     @desc "get following users count"
-    field :followings_count, :integer do
-      arg(:count, :count_type, default_value: :count)
-
-      resolve(dataloader(Accounts, :followings))
-      middleware(M.ConvertToInt)
-    end
+    field(:followings_count, :integer)
 
     @desc "if viewer has followed"
     field(:viewer_has_followed, :boolean)

lib/helper/orm.ex

@@ -265,6 +265,15 @@ defmodule Helper.ORM do
   @doc """
   update meta info for article / comment
   """
+  def update_meta(queryable, meta, changes: changes) when is_map(changes) do
+    meta = meta |> strip_struct
+
+    queryable
+    |> Ecto.Changeset.change(changes)
+    |> Ecto.Changeset.put_embed(:meta, meta)
+    |> Repo.update()
+  end
+
   def update_meta(queryable, meta) do
     meta = meta |> strip_struct
 

priv/repo/migrations/20210529032442_move_follow_count_to_users.exs

@@ -0,0 +1,10 @@
+defmodule GroupherServer.Repo.Migrations.MoveFollowCountToUsers do
+  use Ecto.Migration
+
+  def change do
+    alter table(:users) do
+      add(:followings_count, :integer)
+      add(:followers_count, :integer)
+    end
+  end
+end

test/groupher_server/accounts/fans_test.exs

@@ -22,7 +22,7 @@ defmodule GroupherServer.Test.Accounts.Fans do
       assert found |> Map.get(:followers) |> length == 1
     end
 
-    @tag :wip
+    @tag :wip2
     test "follow user should update follow meta info", ~m(user)a do
       {:ok, user2} = db_insert(:user)
 
@@ -31,6 +31,9 @@ defmodule GroupherServer.Test.Accounts.Fans do
       {:ok, user} = ORM.find(User, user.id)
       {:ok, user2} = ORM.find(User, user2.id)
 
+      assert user.followings_count == 1
+      assert user2.followers_count == 1
+
       assert user2.id in user.meta.following_user_ids
       assert user.id in user2.meta.follower_user_ids
     end
@@ -73,6 +76,7 @@ defmodule GroupherServer.Test.Accounts.Fans do
       assert found |> Map.get(:followers) |> length == 0
     end
 
+    @tag :wip2
     test "undo follow user should update follow meta info", ~m(user)a do
       {:ok, user2} = db_insert(:user)
 
@@ -89,6 +93,9 @@ defmodule GroupherServer.Test.Accounts.Fans do
       {:ok, user} = ORM.find(User, user.id)
       {:ok, user2} = ORM.find(User, user2.id)
 
+      assert user.followings_count == 0
+      assert user2.followers_count == 0
+
       assert user2.id not in user.meta.following_user_ids
       assert user.id not in user2.meta.follower_user_ids
     end