From c50b526ba09fa2fe98f2d1d43d822a38dc8237f2 Mon Sep 17 00:00:00 2001
From: smoogipoo <smoogipoo@smgi.me>
Date: Mon, 19 Apr 2021 16:48:55 +0900
Subject: [PATCH] Remove local state dictionary from SpectatorScreen

---
 .../Online/Spectator/SpectatorStreamingClient.cs   | 12 ++++++++++++
 osu.Game/Screens/Spectate/SpectatorScreen.cs       | 14 +++++++++-----
 2 files changed, 21 insertions(+), 5 deletions(-)

diff --git a/osu.Game/Online/Spectator/SpectatorStreamingClient.cs b/osu.Game/Online/Spectator/SpectatorStreamingClient.cs
index 9def009469..13b12d9add 100644
--- a/osu.Game/Online/Spectator/SpectatorStreamingClient.cs
+++ b/osu.Game/Online/Spectator/SpectatorStreamingClient.cs
@@ -284,6 +284,18 @@ namespace osu.Game.Online.Spectator
             lastSendTime = Time.Current;
         }
 
+        /// <summary>
+        /// Attempts to retrieve the <see cref="SpectatorState"/> for a currently-playing user.
+        /// </summary>
+        /// <param name="userId">The user.</param>
+        /// <param name="state">The current <see cref="SpectatorState"/> for the user, if they're playing. <c>null</c> if the user is not playing.</param>
+        /// <returns><c>true</c> if successful (the user is playing), <c>false</c> otherwise.</returns>
+        public bool TryGetPlayingUserState(int userId, out SpectatorState state)
+        {
+            lock (userLock)
+                return playingUserStates.TryGetValue(userId, out state);
+        }
+
         /// <summary>
         /// Bind an action to <see cref="OnUserBeganPlaying"/> with the option of running the bound action once immediately.
         /// </summary>
diff --git a/osu.Game/Screens/Spectate/SpectatorScreen.cs b/osu.Game/Screens/Spectate/SpectatorScreen.cs
index 7be6c6183b..f554b15abf 100644
--- a/osu.Game/Screens/Spectate/SpectatorScreen.cs
+++ b/osu.Game/Screens/Spectate/SpectatorScreen.cs
@@ -44,7 +44,6 @@ namespace osu.Game.Screens.Spectate
         private readonly object stateLock = new object();
 
         private readonly Dictionary<int, User> userMap = new Dictionary<int, User>();
-        private readonly Dictionary<int, SpectatorState> spectatorStates = new Dictionary<int, SpectatorState>();
         private readonly Dictionary<int, GameplayState> gameplayStates = new Dictionary<int, GameplayState>();
 
         private IBindable<WeakReference<BeatmapSetInfo>> managerUpdated;
@@ -107,9 +106,12 @@ namespace osu.Game.Screens.Spectate
 
             lock (stateLock)
             {
-                foreach (var (userId, state) in spectatorStates)
+                foreach (var (userId, _) in userMap)
                 {
-                    if (beatmapSet.Beatmaps.Any(b => b.OnlineBeatmapID == state.BeatmapID))
+                    if (!spectatorClient.TryGetPlayingUserState(userId, out var userState))
+                        continue;
+
+                    if (beatmapSet.Beatmaps.Any(b => b.OnlineBeatmapID == userState.BeatmapID))
                         updateGameplayState(userId);
                 }
             }
@@ -125,7 +127,6 @@ namespace osu.Game.Screens.Spectate
                 if (!userMap.ContainsKey(userId))
                     return;
 
-                spectatorStates[userId] = state;
                 Schedule(() => OnUserStateChanged(userId, state));
 
                 updateGameplayState(userId);
@@ -138,7 +139,10 @@ namespace osu.Game.Screens.Spectate
             {
                 Debug.Assert(userMap.ContainsKey(userId));
 
-                var spectatorState = spectatorStates[userId];
+                // The user may have stopped playing.
+                if (!spectatorClient.TryGetPlayingUserState(userId, out var spectatorState))
+                    return;
+
                 var user = userMap[userId];
 
                 var resolvedRuleset = rulesets.AvailableRulesets.FirstOrDefault(r => r.ID == spectatorState.RulesetID)?.CreateInstance();