PaperMC/patches/server/0396-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 9fba89aa8b1c257cdc3a63a5bd137320d66a37ec..b06789336098233b642b769b0fd60e740459874c 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
@@ -189,9 +189,29 @@ 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.path == null && net.minecraft.server.MinecraftServer.currentTick < this.lastFailure + 40) {
+            return false;
+        }
+        // Paper end
         Path path = this.createPath(entity, 1);
-        return path != null && this.moveTo(path, speed);
+        // Paper start - Pathfinding optimizations
+        if (path != null && this.moveTo(path, speed)) {
+            this.lastFailure = 0;
+            this.pathfindFailures = 0;
+            return true;
+        } else {
+            this.pathfindFailures++;
+            this.lastFailure = net.minecraft.server.MinecraftServer.currentTick;
+            return false;
+        }
+        // Paper end
     }
 
     public boolean moveTo(@Nullable Path path, double speed) {