From 496e11e56ec8b5edb9fb0b96e54fabed868fb901 Mon Sep 17 00:00:00 2001
From: Thibault Duplessis <thibault.duplessis@gmail.com>
Date: Sat, 18 Jan 2020 14:10:02 -0600
Subject: [PATCH] preload student light users

---
 app/controllers/Clas.scala               | 9 +++++++--
 modules/user/src/main/LightUserApi.scala | 7 ++++---
 2 files changed, 11 insertions(+), 5 deletions(-)

diff --git a/app/controllers/Clas.scala b/app/controllers/Clas.scala
index ca68a3db2a..46978cb263 100644
--- a/app/controllers/Clas.scala
+++ b/app/controllers/Clas.scala
@@ -45,11 +45,15 @@ final class Clas(
     }
   }
 
+  private def preloadStudentUsers(students: List[lila.clas.Student.WithUser]): Unit =
+    env.user.lightUserApi.preloadUsers(students.map(_.user))
+
   def show(id: String) = Auth { implicit ctx => me =>
     isGranted(_.Teacher).??(env.clas.api.clas.isTeacherOf(me, lila.clas.Clas.Id(id))) flatMap {
       case true =>
         WithClass(me, id) { _ => clas =>
           env.clas.api.student.allOfWithUsers(clas) map { students =>
+            preloadStudentUsers(students)
             views.html.clas.clas.showToTeacher(clas, students)
           }
         }
@@ -57,9 +61,10 @@ final class Clas(
         env.clas.api.clas.byId(lila.clas.Clas.Id(id)) flatMap {
           _ ?? { clas =>
             env.clas.api.student.activeOfWithUsers(clas) flatMap { students =>
-              if (students.exists(_.student is me))
+              if (students.exists(_.student is me)) {
+                preloadStudentUsers(students)
                 Ok(views.html.clas.clas.showToStudent(clas, students)).fuccess
-              else notFound
+              } else notFound
             }
           }
         }
diff --git a/modules/user/src/main/LightUserApi.scala b/modules/user/src/main/LightUserApi.scala
index b581cd6fa7..b481120ae9 100644
--- a/modules/user/src/main/LightUserApi.scala
+++ b/modules/user/src/main/LightUserApi.scala
@@ -23,9 +23,10 @@ final class LightUserApi(
 
   def invalidate = cache invalidate _
 
-  def preloadOne              = cache preloadOne _
-  def preloadMany             = cache preloadMany _
-  def preloadUser(user: User) = cache.set(user.id, user.light.some)
+  def preloadOne                     = cache preloadOne _
+  def preloadMany                    = cache preloadMany _
+  def preloadUser(user: User)        = cache.set(user.id, user.light.some)
+  def preloadUsers(users: Seq[User]) = users.foreach(preloadUser)
 
   private val cache = cacheApi.sync[User.ID, Option[LightUser]](
     name = "user.light",