From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Thu, 13 Sep 2018 20:51:50 -0400
Subject: [PATCH] Performance & Concurrency Improvements to Permissions

Modifying of permissions was only half protected, enabling concurrency
issues to occur if permissions were modified async.

While no plugin really should be doing that, modifying operations
are not heavily called, so they are safe to add synchronization to.

Now, all modification API's will be synchronized ensuring safety.

Additionally, hasPermission was victim to a common java newbie mistake
of calling if (containsKey(k)) return get(k), resulting in 2 map lookups.

Optimized it to simply be a single get call cutting permission map
lookups in half.

diff --git a/src/main/java/org/bukkit/permissions/PermissibleBase.java b/src/main/java/org/bukkit/permissions/PermissibleBase.java
index d0fd41a0ddee550cf880bb212b15dfe79cb4e683..75b77cc4fe189b4b6baa1af3663dc492e992a266 100644
--- a/src/main/java/org/bukkit/permissions/PermissibleBase.java
+++ b/src/main/java/org/bukkit/permissions/PermissibleBase.java
@@ -73,8 +73,11 @@ public class PermissibleBase implements Permissible {
 
         String name = inName.toLowerCase(Locale.ROOT);
 
-        if (isPermissionSet(name)) {
-            return permissions.get(name).getValue();
+        // Paper start
+        PermissionAttachmentInfo info = permissions.get(name);
+        if (info != null) {
+            return info.getValue();
+            // Paper end
         } else {
             Permission perm = Bukkit.getServer().getPluginManager().getPermission(name);
 
@@ -94,15 +97,18 @@ public class PermissibleBase implements Permissible {
 
         String name = perm.getName().toLowerCase(Locale.ROOT);
 
-        if (isPermissionSet(name)) {
-            return permissions.get(name).getValue();
+        // Paper start
+        PermissionAttachmentInfo info = permissions.get(name);
+        if (info != null) {
+            return info.getValue();
         }
+        // Paper end
         return perm.getDefault().getValue(isOp());
     }
 
     @Override
     @NotNull
-    public PermissionAttachment addAttachment(@NotNull Plugin plugin, @NotNull String name, boolean value) {
+    public synchronized PermissionAttachment addAttachment(@NotNull Plugin plugin, @NotNull String name, boolean value) { // Paper - synchronized
         if (name == null) {
             throw new IllegalArgumentException("Permission name cannot be null");
         } else if (plugin == null) {
@@ -121,7 +127,7 @@ public class PermissibleBase implements Permissible {
 
     @Override
     @NotNull
-    public PermissionAttachment addAttachment(@NotNull Plugin plugin) {
+    public synchronized PermissionAttachment addAttachment(@NotNull Plugin plugin) { // Paper - synchronized
         if (plugin == null) {
             throw new IllegalArgumentException("Plugin cannot be null");
         } else if (!plugin.isEnabled()) {
@@ -137,7 +143,7 @@ public class PermissibleBase implements Permissible {
     }
 
     @Override
-    public void removeAttachment(@NotNull PermissionAttachment attachment) {
+    public synchronized void removeAttachment(@NotNull PermissionAttachment attachment) { // Paper - synchronized
         if (attachment == null) {
             throw new IllegalArgumentException("Attachment cannot be null");
         }
@@ -156,7 +162,7 @@ public class PermissibleBase implements Permissible {
     }
 
     @Override
-    public void recalculatePermissions() {
+    public synchronized void recalculatePermissions() { // Paper - synchronized
         clearPermissions();
         Set<Permission> defaults = Bukkit.getServer().getPluginManager().getDefaultPermissions(isOp());
         Bukkit.getServer().getPluginManager().subscribeToDefaultPerms(isOp(), parent);
@@ -205,7 +211,7 @@ public class PermissibleBase implements Permissible {
 
     @Override
     @Nullable
-    public PermissionAttachment addAttachment(@NotNull Plugin plugin, @NotNull String name, boolean value, int ticks) {
+    public synchronized PermissionAttachment addAttachment(@NotNull Plugin plugin, @NotNull String name, boolean value, int ticks) { // Paper
         if (name == null) {
             throw new IllegalArgumentException("Permission name cannot be null");
         } else if (plugin == null) {
@@ -225,7 +231,7 @@ public class PermissibleBase implements Permissible {
 
     @Override
     @Nullable
-    public PermissionAttachment addAttachment(@NotNull Plugin plugin, int ticks) {
+    public synchronized PermissionAttachment addAttachment(@NotNull Plugin plugin, int ticks) { // Paper - synchronized
         if (plugin == null) {
             throw new IllegalArgumentException("Plugin cannot be null");
         } else if (!plugin.isEnabled()) {
@@ -245,7 +251,7 @@ public class PermissibleBase implements Permissible {
 
     @Override
     @NotNull
-    public Set<PermissionAttachmentInfo> getEffectivePermissions() {
+    public synchronized Set<PermissionAttachmentInfo> getEffectivePermissions() { // Paper - synchronized
         return new HashSet<PermissionAttachmentInfo>(permissions.values());
     }