Paper/Spigot-Server-Patches/0438-Optimize-Pathfinding.patch

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Thu, 3 Mar 2016 02:02:07 -0600
Subject: [PATCH] Optimize Pathfinding

Prevents pathfinding from spamming failures for things such as
arrow attacks.

diff --git a/src/main/java/net/minecraft/server/NavigationAbstract.java b/src/main/java/net/minecraft/server/NavigationAbstract.java
index 64b991859f0f3ca7d932b8acc8aeed401e22a388..1558c5f8256f50be6850f1d7f70eee3e8ec76496 100644
--- a/src/main/java/net/minecraft/server/NavigationAbstract.java
+++ b/src/main/java/net/minecraft/server/NavigationAbstract.java
@@ -11,7 +11,7 @@ public abstract class NavigationAbstract {
     protected final EntityInsentient a; public Entity getEntity() { return a; } // Paper - OBFHELPER
     protected final World b;
     @Nullable
-    protected PathEntity c;
+    protected PathEntity c; protected final PathEntity getCurrentPath() { return this.c; } // Paper - OBFHELPER
     protected double d;
     protected int e;
     protected int f;
@@ -163,10 +163,30 @@ public abstract class NavigationAbstract {
         return this.a(this.a(d0, d1, d2, 1), d3);
     }
 
+    // Paper start - optimise pathfinding
+    private int lastFailure = 0;
+    private int pathfindFailures = 0;
+    // Paper end
+
     public boolean a(Entity entity, double d0) {
+        // Paper start - Pathfinding optimizations
+        if (this.pathfindFailures > 10 && this.getCurrentPath() == null && MinecraftServer.currentTick < this.lastFailure + 40) {
+            return false;
+        }
+        // Paper end
         PathEntity pathentity = this.a(entity, 1);
 
-        return pathentity != null && this.a(pathentity, d0);
+        // Paper start - Pathfinding optimizations
+        if (pathentity != null && this.a(pathentity, d0)) {
+            this.lastFailure = 0;
+            this.pathfindFailures = 0;
+            return true;
+        } else {
+            this.pathfindFailures++;
+            this.lastFailure = MinecraftServer.currentTick;
+            return false;
+        }
+        // Paper end
     }
 
     public boolean setDestination(@Nullable PathEntity pathentity, double speed) { return a(pathentity, speed); } // Paper - OBFHELPER