From 422260797b68cc6e3710d327c4e3accc66d4797c Mon Sep 17 00:00:00 2001
From: Dean Herbert <pe@ppy.sh>
Date: Tue, 12 Jan 2021 16:03:12 +0900
Subject: [PATCH] Revert polling changes to fix participant list display

It turns out this polling was necessary to get extra data that isn't
included in the main listing request. It was removed deemed useless, and
in order to fix the order of rooms changing when selecting a room.
Weirdly, I can't reproduce this happening any more, and on close
inspection of the code can't see how it could happen in the first place.

For now, let's revert this change and iterate from there, if/when the
same issue arises again.

I've discussed avoiding this second poll by potentially including more
data (just `user_id`s?) in the main listing request, but not 100% sure
on this - even if the returned data is minimal it's an extra join
server-side, which could cause performance issues for large numbers of
rooms.
---
 .../TestSceneMultiplayerRoomManager.cs        |  1 +
 .../OnlinePlay/Multiplayer/Multiplayer.cs     |  5 +++-
 .../Multiplayer/MultiplayerRoomManager.cs     | 28 ++++++++++++++++++-
 3 files changed, 32 insertions(+), 2 deletions(-)

diff --git a/osu.Game.Tests/Visual/Multiplayer/TestSceneMultiplayerRoomManager.cs b/osu.Game.Tests/Visual/Multiplayer/TestSceneMultiplayerRoomManager.cs
index 80d1acd145..7a3845cbf3 100644
--- a/osu.Game.Tests/Visual/Multiplayer/TestSceneMultiplayerRoomManager.cs
+++ b/osu.Game.Tests/Visual/Multiplayer/TestSceneMultiplayerRoomManager.cs
@@ -143,6 +143,7 @@ namespace osu.Game.Tests.Visual.Multiplayer
                 RoomManager =
                 {
                     TimeBetweenListingPolls = { Value = 1 },
+                    TimeBetweenSelectionPolls = { Value = 1 }
                 }
             };
 
diff --git a/osu.Game/Screens/OnlinePlay/Multiplayer/Multiplayer.cs b/osu.Game/Screens/OnlinePlay/Multiplayer/Multiplayer.cs
index 310617a0bc..76f5c74433 100644
--- a/osu.Game/Screens/OnlinePlay/Multiplayer/Multiplayer.cs
+++ b/osu.Game/Screens/OnlinePlay/Multiplayer/Multiplayer.cs
@@ -33,6 +33,7 @@ namespace osu.Game.Screens.OnlinePlay.Multiplayer
             if (!this.IsCurrentScreen())
             {
                 multiplayerRoomManager.TimeBetweenListingPolls.Value = 0;
+                multiplayerRoomManager.TimeBetweenSelectionPolls.Value = 0;
             }
             else
             {
@@ -40,16 +41,18 @@ namespace osu.Game.Screens.OnlinePlay.Multiplayer
                 {
                     case LoungeSubScreen _:
                         multiplayerRoomManager.TimeBetweenListingPolls.Value = isIdle ? 120000 : 15000;
+                        multiplayerRoomManager.TimeBetweenSelectionPolls.Value = isIdle ? 120000 : 15000;
                         break;
 
                     // Don't poll inside the match or anywhere else.
                     default:
                         multiplayerRoomManager.TimeBetweenListingPolls.Value = 0;
+                        multiplayerRoomManager.TimeBetweenSelectionPolls.Value = 0;
                         break;
                 }
             }
 
-            Logger.Log($"Polling adjusted (listing: {multiplayerRoomManager.TimeBetweenListingPolls.Value})");
+            Logger.Log($"Polling adjusted (listing: {multiplayerRoomManager.TimeBetweenListingPolls.Value}, selection: {multiplayerRoomManager.TimeBetweenSelectionPolls.Value})");
         }
 
         protected override Room CreateNewRoom()
diff --git a/osu.Game/Screens/OnlinePlay/Multiplayer/MultiplayerRoomManager.cs b/osu.Game/Screens/OnlinePlay/Multiplayer/MultiplayerRoomManager.cs
index 5c327266a3..3cb263298f 100644
--- a/osu.Game/Screens/OnlinePlay/Multiplayer/MultiplayerRoomManager.cs
+++ b/osu.Game/Screens/OnlinePlay/Multiplayer/MultiplayerRoomManager.cs
@@ -23,7 +23,7 @@ namespace osu.Game.Screens.OnlinePlay.Multiplayer
         private StatefulMultiplayerClient multiplayerClient { get; set; }
 
         public readonly Bindable<double> TimeBetweenListingPolls = new Bindable<double>();
-
+        public readonly Bindable<double> TimeBetweenSelectionPolls = new Bindable<double>();
         private readonly IBindable<bool> isConnected = new Bindable<bool>();
         private readonly Bindable<bool> allowPolling = new Bindable<bool>();
 
@@ -119,6 +119,11 @@ namespace osu.Game.Screens.OnlinePlay.Multiplayer
                 TimeBetweenPolls = { BindTarget = TimeBetweenListingPolls },
                 AllowPolling = { BindTarget = allowPolling }
             },
+            new MultiplayerSelectionPollingComponent
+            {
+                TimeBetweenPolls = { BindTarget = TimeBetweenSelectionPolls },
+                AllowPolling = { BindTarget = allowPolling }
+            }
         };
 
         private class MultiplayerListingPollingComponent : ListingPollingComponent
@@ -141,5 +146,26 @@ namespace osu.Game.Screens.OnlinePlay.Multiplayer
 
             protected override Task Poll() => !AllowPolling.Value ? Task.CompletedTask : base.Poll();
         }
+
+        private class MultiplayerSelectionPollingComponent : SelectionPollingComponent
+        {
+            public readonly IBindable<bool> AllowPolling = new Bindable<bool>();
+
+            protected override void LoadComplete()
+            {
+                base.LoadComplete();
+
+                AllowPolling.BindValueChanged(allowPolling =>
+                {
+                    if (!allowPolling.NewValue)
+                        return;
+
+                    if (IsLoaded)
+                        PollImmediately();
+                });
+            }
+
+            protected override Task Poll() => !AllowPolling.Value ? Task.CompletedTask : base.Poll();
+        }
     }
 }