Paper/patches/server-remapped/0439-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/world/entity/ai/navigation/PathNavigation.java b/src/main/java/net/minecraft/world/entity/ai/navigation/PathNavigation.java
index a362506f38e8d30543b6cd6d215db561290dac76..c501e42b6fef4af065807182dc5b4c444e74e310 100644
--- a/src/main/java/net/minecraft/world/entity/ai/navigation/PathNavigation.java
+++ b/src/main/java/net/minecraft/world/entity/ai/navigation/PathNavigation.java
@@ -11,6 +11,7 @@ import net.minecraft.core.Position;
 import net.minecraft.core.Vec3i;
 import net.minecraft.network.protocol.game.DebugPackets;
 import net.minecraft.server.MCUtil;
+import net.minecraft.server.MinecraftServer;
 import net.minecraft.util.Mth;
 import net.minecraft.world.entity.Entity;
 import net.minecraft.world.entity.Mob;
@@ -32,7 +33,7 @@ public abstract class PathNavigation {
     protected final Mob mob; public Entity getEntity() { return mob; } // Paper - OBFHELPER
     protected final Level level;
     @Nullable
-    protected Path path;
+    protected Path path; protected final Path getCurrentPath() { return this.path; } // Paper - OBFHELPER
     protected double speedModifier;
     protected int tick;
     protected int lastStuckCheck;
@@ -184,10 +185,30 @@ public abstract class PathNavigation {
         return this.moveTo(this.createPath(x, y, z, 1), speed);
     }
 
+    // Paper start - optimise pathfinding
+    private int lastFailure = 0;
+    private int pathfindFailures = 0;
+    // Paper end
+
     public boolean moveTo(Entity entity, double speed) {
+        // Paper start - Pathfinding optimizations
+        if (this.pathfindFailures > 10 && this.getCurrentPath() == null && MinecraftServer.currentTick < this.lastFailure + 40) {
+            return false;
+        }
+        // Paper end
         Path pathentity = this.createPath(entity, 1);
 
-        return pathentity != null && this.moveTo(pathentity, speed);
+        // Paper start - Pathfinding optimizations
+        if (pathentity != null && this.moveTo(pathentity, speed)) {
+            this.lastFailure = 0;
+            this.pathfindFailures = 0;
+            return true;
+        } else {
+            this.pathfindFailures++;
+            this.lastFailure = MinecraftServer.currentTick;
+            return false;
+        }
+        // Paper end
     }
 
     public boolean setDestination(@Nullable Path pathentity, double speed) { return moveTo(pathentity, speed); } // Paper - OBFHELPER