From 4e17634ee27ab7dfc33753c1750d8f91e6e2b206 Mon Sep 17 00:00:00 2001
From: Dean Herbert <pe@ppy.sh>
Date: Mon, 2 Nov 2020 17:31:04 +0900
Subject: [PATCH] Add (temporary) local user cache to avoid re-querying API
 each display

---
 .../Dashboard/CurrentlyPlayingDisplay.cs      | 25 ++++++++++++++-----
 1 file changed, 19 insertions(+), 6 deletions(-)

diff --git a/osu.Game/Overlays/Dashboard/CurrentlyPlayingDisplay.cs b/osu.Game/Overlays/Dashboard/CurrentlyPlayingDisplay.cs
index d71e582c05..b461da4476 100644
--- a/osu.Game/Overlays/Dashboard/CurrentlyPlayingDisplay.cs
+++ b/osu.Game/Overlays/Dashboard/CurrentlyPlayingDisplay.cs
@@ -1,6 +1,7 @@
 // Copyright (c) ppy Pty Ltd <contact@ppy.sh>. Licensed under the MIT Licence.
 // See the LICENCE file in the repository root for full licence text.
 
+using System.Collections.Generic;
 using System.Collections.Specialized;
 using System.Linq;
 using osu.Framework.Allocation;
@@ -43,6 +44,9 @@ namespace osu.Game.Overlays.Dashboard
         [Resolved]
         private IAPIProvider api { get; set; }
 
+        // temporary, should be game-global but i don't want to add more manager classes for now.
+        private static readonly Dictionary<int, User> user_cache = new Dictionary<int, User>();
+
         protected override void LoadComplete()
         {
             base.LoadComplete();
@@ -53,15 +57,24 @@ namespace osu.Game.Overlays.Dashboard
                 switch (e.Action)
                 {
                     case NotifyCollectionChangedAction.Add:
-                        foreach (var u in e.NewItems.OfType<int>())
+                        foreach (int userId in e.NewItems.OfType<int>())
                         {
-                            var request = new GetUserRequest(u);
-                            request.Success += user => Schedule(() =>
+                            if (user_cache.TryGetValue(userId, out var user))
                             {
-                                if (playingUsers.Contains((int)user.Id))
-                                    userFlow.Add(createUserPanel(user));
-                            });
+                                addUser(user);
+                                continue;
+                            }
+
+                            var request = new GetUserRequest(userId);
+                            request.Success += u => Schedule(() => addUser(u));
                             api.Queue(request);
+
+                            void addUser(User u)
+                            {
+                                user_cache[userId] = u;
+                                if (playingUsers.Contains(userId))
+                                    userFlow.Add(createUserPanel(u));
+                            }
                         }
 
                         break;