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.

diff --git a/src/main/java/net/minecraft/server/DedicatedServer.java b/src/main/java/net/minecraft/server/DedicatedServer.java
index ef226a9a9e1fbd729cf6349eb3ff63bf4b4a2d08..5745c6aa86a0411be8bc49ff8e9dd655e91fd68e 100644
--- a/src/main/java/net/minecraft/server/DedicatedServer.java
+++ b/src/main/java/net/minecraft/server/DedicatedServer.java
@@ -212,7 +212,7 @@ public class DedicatedServer extends MinecraftServer implements IMinecraftServer
         }
 
         if (this.convertNames()) {
-            this.getUserCache().b();
+            this.getUserCache().b(false); // Paper
         }
 
         if (!NameReferencingFileConverter.e(this)) {
diff --git a/src/main/java/net/minecraft/server/MinecraftServer.java b/src/main/java/net/minecraft/server/MinecraftServer.java
index 165e915c9c76b603b61d0548a85ec8e09f25ca05..9dd54bea5f9a7d1cb638100312855135f83bcaf9 100644
--- a/src/main/java/net/minecraft/server/MinecraftServer.java
+++ b/src/main/java/net/minecraft/server/MinecraftServer.java
@@ -786,7 +786,7 @@ public abstract class MinecraftServer extends IAsyncTaskHandlerReentrant<TickTas
         } catch (java.lang.InterruptedException ignored) {} // Paper
         if (org.spigotmc.SpigotConfig.saveUserCacheOnStopOnly) {
             LOGGER.info("Saving usercache.json");
-            this.getUserCache().b();
+            this.getUserCache().b(false); // Paper
         }
         // Spigot end
 
diff --git a/src/main/java/net/minecraft/server/UserCache.java b/src/main/java/net/minecraft/server/UserCache.java
index ce81aaf3e6ae97ad2af2aad6b668bdd4e18abcf1..15222ed19f049b7465a43a8651584a8a4c5fd666 100644
--- a/src/main/java/net/minecraft/server/UserCache.java
+++ b/src/main/java/net/minecraft/server/UserCache.java
@@ -106,7 +106,7 @@ public class UserCache {
         return UserCache.b;
     }
 
-    public void a(GameProfile gameprofile) {
+    public synchronized void a(GameProfile gameprofile) { // Paper - synchronize
         Calendar calendar = Calendar.getInstance();
 
         calendar.setTime(new Date());
@@ -115,7 +115,7 @@ public class UserCache {
         UserCache.UserCacheEntry usercache_usercacheentry = new UserCache.UserCacheEntry(gameprofile, date);
 
         this.a(usercache_usercacheentry);
-        if( !org.spigotmc.SpigotConfig.saveUserCacheOnStopOnly ) this.b(); // Spigot - skip saving if disabled
+        if( !org.spigotmc.SpigotConfig.saveUserCacheOnStopOnly ) this.b(true); // Spigot - skip saving if disabled // Paper - async
     }
 
     private long d() {
@@ -123,7 +123,7 @@ public class UserCache {
     }
 
     @Nullable
-    public GameProfile getProfile(String s) {
+    public synchronized GameProfile getProfile(String s) { // Paper - synchronize
         String s1 = s.toLowerCase(Locale.ROOT);
         UserCache.UserCacheEntry usercache_usercacheentry = (UserCache.UserCacheEntry) this.c.get(s1);
         boolean flag = false;
@@ -149,7 +149,7 @@ public class UserCache {
         }
 
         if (flag && !org.spigotmc.SpigotConfig.saveUserCacheOnStopOnly) { // Spigot - skip saving if disabled
-            this.b();
+            this.b(true); // Paper
         }
 
         return gameprofile;
@@ -231,7 +231,7 @@ public class UserCache {
         return arraylist;
     }
 
-    public void b() {
+    public void b(boolean asyncSave) { // Paper
         JsonArray jsonarray = new JsonArray();
         DateFormat dateformat = e();
 
@@ -239,6 +239,7 @@ public class UserCache {
             jsonarray.add(a(usercache_usercacheentry, dateformat));
         });
         String s = this.f.toJson(jsonarray);
+        Runnable save = () -> { // Paper
 
         try {
             BufferedWriter bufferedwriter = Files.newWriter(this.g, StandardCharsets.UTF_8);
@@ -266,6 +267,14 @@ public class UserCache {
         } catch (IOException ioexception) {
             ;
         }
+        // Paper start
+        };
+        if (asyncSave) {
+            MCUtil.scheduleAsyncTask(save);
+        } else {
+            save.run();
+        }
+        // Paper end
 
     }