From 8018ae7ae5ab3747e5fefdc9a094fe4b3d90dbb6 Mon Sep 17 00:00:00 2001
From: href <href@random.sh>
Date: Sat, 26 Jan 2019 15:55:53 +0100
Subject: [PATCH] Join on preloads to avoid N+1 queries

---
 lib/pleroma/notification.ex     | 6 ++++--
 lib/pleroma/plugs/oauth_plug.ex | 7 ++++++-
 2 files changed, 10 insertions(+), 3 deletions(-)

diff --git a/lib/pleroma/notification.ex b/lib/pleroma/notification.ex
index e47145601..2364d36da 100644
--- a/lib/pleroma/notification.ex
+++ b/lib/pleroma/notification.ex
@@ -35,7 +35,8 @@ def for_user(user, opts \\ %{}) do
         n in Notification,
         where: n.user_id == ^user.id,
         order_by: [desc: n.id],
-        preload: [:activity],
+        join: activity in assoc(n, :activity),
+        preload: [activity: activity],
         limit: 20
       )
 
@@ -66,7 +67,8 @@ def get(%{id: user_id} = _user, id) do
       from(
         n in Notification,
         where: n.id == ^id,
-        preload: [:activity]
+        join: activity in assoc(n, :activity),
+        preload: [activity: activity]
       )
 
     notification = Repo.one(query)
diff --git a/lib/pleroma/plugs/oauth_plug.ex b/lib/pleroma/plugs/oauth_plug.ex
index 437aa95b3..945a1d49f 100644
--- a/lib/pleroma/plugs/oauth_plug.ex
+++ b/lib/pleroma/plugs/oauth_plug.ex
@@ -33,7 +33,12 @@ def call(conn, _) do
   #
   @spec fetch_user_and_token(String.t()) :: {:ok, User.t(), Token.t()} | nil
   defp fetch_user_and_token(token) do
-    query = from(q in Token, where: q.token == ^token, preload: [:user])
+    query =
+      from(t in Token,
+        where: t.token == ^token,
+        join: user in assoc(t, :user),
+        preload: [user: user]
+      )
 
     with %Token{user: %{info: %{deactivated: false} = _} = user} = token_record <- Repo.one(query) do
       {:ok, user, token_record}