From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Mon, 16 May 2016 20:47:41 -0400
Subject: [PATCH] Optimize UserCache / Thread Safe

Because Techable keeps complaining about how this isn't thread safe,
easier to do this than replace the entire thing.

Additionally, move Saving of the User cache to be done async, incase
the user never changed the default setting for Spigot's save on stop only.

1.17: TODO does this need the synchronized blocks anymore?

diff --git a/src/main/java/net/minecraft/server/MinecraftServer.java b/src/main/java/net/minecraft/server/MinecraftServer.java
index ef231e11b90b24418a77b62f5fe766c9ac10c09b..74073d3f8c9dda6f10e9fb34071dae079b73fb24 100644
--- a/src/main/java/net/minecraft/server/MinecraftServer.java
+++ b/src/main/java/net/minecraft/server/MinecraftServer.java
@@ -963,7 +963,7 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
         } catch (java.lang.InterruptedException ignored) {} // Paper
         if (org.spigotmc.SpigotConfig.saveUserCacheOnStopOnly) {
             MinecraftServer.LOGGER.info("Saving usercache.json");
-            this.getProfileCache().save();
+            this.getProfileCache().save(false); // Paper
         }
         // Spigot end
 
diff --git a/src/main/java/net/minecraft/server/dedicated/DedicatedServer.java b/src/main/java/net/minecraft/server/dedicated/DedicatedServer.java
index 566390d02b2af4a0f2c867b7ff8116a8301e8497..e2095308a8ec8471b04acce929d314fd828bc3de 100644
--- a/src/main/java/net/minecraft/server/dedicated/DedicatedServer.java
+++ b/src/main/java/net/minecraft/server/dedicated/DedicatedServer.java
@@ -256,7 +256,7 @@ public class DedicatedServer extends MinecraftServer implements ServerInterface
         }
 
         if (this.convertOldUsers()) {
-            this.getProfileCache().save();
+            this.getProfileCache().save(false); // Paper
         }
 
         if (!OldUsersConverter.serverReadyAfterUserconversion(this)) {
diff --git a/src/main/java/net/minecraft/server/players/GameProfileCache.java b/src/main/java/net/minecraft/server/players/GameProfileCache.java
index 1dd9b362384543e17b537dd209665d956214916d..c70b4727fe0ae9ff7b9db08a9711272994159b96 100644
--- a/src/main/java/net/minecraft/server/players/GameProfileCache.java
+++ b/src/main/java/net/minecraft/server/players/GameProfileCache.java
@@ -117,7 +117,7 @@ public class GameProfileCache {
         return GameProfileCache.usesAuthentication;
     }
 
-    public void add(GameProfile profile) {
+    public synchronized void add(GameProfile profile) { // Paper - synchronize
         Calendar calendar = Calendar.getInstance();
 
         calendar.setTime(new Date());
@@ -126,7 +126,7 @@ public class GameProfileCache {
         GameProfileCache.GameProfileInfo usercache_usercacheentry = new GameProfileCache.GameProfileInfo(profile, date);
 
         this.safeAdd(usercache_usercacheentry);
-        if( !org.spigotmc.SpigotConfig.saveUserCacheOnStopOnly ) this.save(); // Spigot - skip saving if disabled
+        if( !org.spigotmc.SpigotConfig.saveUserCacheOnStopOnly ) this.save(true); // Spigot - skip saving if disabled // Paper - async
     }
 
     private long getNextOperation() {
@@ -134,7 +134,7 @@ public class GameProfileCache {
     }
 
     @Nullable
-    public GameProfile get(String name) {
+    public synchronized GameProfile get(String name) { // Paper - synchronize
         String s1 = name.toLowerCase(Locale.ROOT);
         GameProfileCache.GameProfileInfo usercache_usercacheentry = (GameProfileCache.GameProfileInfo) this.profilesByName.get(s1);
         boolean flag = false;
@@ -160,7 +160,7 @@ public class GameProfileCache {
         }
 
         if (flag && !org.spigotmc.SpigotConfig.saveUserCacheOnStopOnly) { // Spigot - skip saving if disabled
-            this.save();
+            this.save(true); // Paper
         }
 
         return gameprofile;
@@ -273,7 +273,7 @@ public class GameProfileCache {
         return arraylist;
     }
 
-    public void save() {
+    public void save(boolean asyncSave) { // Paper
         JsonArray jsonarray = new JsonArray();
         DateFormat dateformat = GameProfileCache.createDateFormat();
 
@@ -281,6 +281,7 @@ public class GameProfileCache {
             jsonarray.add(GameProfileCache.writeGameProfile(usercache_usercacheentry, dateformat));
         });
         String s = this.gson.toJson(jsonarray);
+        Runnable save = () -> { // Paper
 
         try {
             BufferedWriter bufferedwriter = Files.newWriter(this.file, StandardCharsets.UTF_8);
@@ -305,6 +306,14 @@ public class GameProfileCache {
         } catch (IOException ioexception) {
             ;
         }
+        // Paper start
+        };
+        if (asyncSave) {
+            net.minecraft.server.MCUtil.scheduleAsyncTask(save);
+        } else {
+            save.run();
+        }
+        // Paper end
 
     }