Add iterator cache to UnsafeList and use it in hotspots

Adds a specialized iterator for the list and a pool of iterators to avoid
object churn. Also optimizes the clear() method to reduce object creation.

3 files changed, 11 insertions, 6 deletions

diff --git a/src/main/java/net/minecraft/server/Chunk.java b/src/main/java/net/minecraft/server/Chunk.java
index 9fedd372..fb9bf205 100644
--- a/src/main/java/net/minecraft/server/Chunk.java
+++ b/src/main/java/net/minecraft/server/Chunk.java
@@ -57,7 +57,7 @@ public class Chunk {
         this.heightMap = new int[256];
 
         for (int k = 0; k < this.entitySlices.length; ++k) {
-            this.entitySlices[k] = new ArrayList();
+            this.entitySlices[k] = new org.bukkit.craftbukkit.util.UnsafeList(); // CraftBukkit - ArrayList -> UnsafeList
         }
 
         Arrays.fill(this.b, -999);
diff --git a/src/main/java/net/minecraft/server/PathfinderGoalSelector.java b/src/main/java/net/minecraft/server/PathfinderGoalSelector.java
index dc16a625..9ef8ec76 100644
--- a/src/main/java/net/minecraft/server/PathfinderGoalSelector.java
+++ b/src/main/java/net/minecraft/server/PathfinderGoalSelector.java
@@ -4,10 +4,14 @@ import java.util.ArrayList;
 import java.util.Iterator;
 import java.util.List;
 
+import org.bukkit.craftbukkit.util.UnsafeList; // CraftBukkit
+
 public class PathfinderGoalSelector {
 
-    private List a = new ArrayList();
-    private List b = new ArrayList();
+    // CraftBukkit start - ArrayList -> UnsafeList
+    private List a = new UnsafeList();
+    private List b = new UnsafeList();
+    // CraftBukkit end
     private final MethodProfiler c;
     private int d = 0;
     private int e = 3;
@@ -21,7 +25,7 @@ public class PathfinderGoalSelector {
     }
 
     public void a() {
-        ArrayList arraylist = new ArrayList();
+        UnsafeList arraylist = new UnsafeList(); // CraftBukkit - ArrayList -> UnsafeList
         Iterator iterator;
         PathfinderGoalSelectorItem pathfindergoalselectoritem;
 
diff --git a/src/main/java/net/minecraft/server/World.java b/src/main/java/net/minecraft/server/World.java
index d552df0f..56c5df05 100644
--- a/src/main/java/net/minecraft/server/World.java
+++ b/src/main/java/net/minecraft/server/World.java
@@ -10,6 +10,7 @@ import java.util.concurrent.Callable;
 // CraftBukkit start
 import org.bukkit.Bukkit;
 import org.bukkit.craftbukkit.util.LongHashset;
+import org.bukkit.craftbukkit.util.UnsafeList;
 import org.bukkit.generator.ChunkGenerator;
 import org.bukkit.craftbukkit.CraftServer;
 import org.bukkit.craftbukkit.CraftWorld;
@@ -54,7 +55,7 @@ public abstract class World implements IBlockAccess {
     public final VillageCollection villages = new VillageCollection(this);
     protected final VillageSiege siegeManager = new VillageSiege(this);
     public final MethodProfiler methodProfiler;
-    private ArrayList d = new ArrayList();
+    private UnsafeList d = new UnsafeList(); // CraftBukkit - ArrayList -> UnsafeList
     private boolean L;
     // CraftBukkit start - public, longhashset
     public boolean allowMonsters = true;
@@ -112,7 +113,7 @@ public abstract class World implements IBlockAccess {
 
         this.M = this.random.nextInt(12000);
         this.J = new int['\u8000'];
-        this.N = new ArrayList();
+        this.N = new UnsafeList(); // CraftBukkit - ArrayList -> UnsafeList
         this.isStatic = false;
         this.dataManager = idatamanager;
         this.methodProfiler = methodprofiler;