Add pathfinding chunkload optimization

Author: clienthax

src/main/java/org/spongepowered/common/config/category/OptimizationCategory.java

@@ -122,6 +122,13 @@ public class OptimizationCategory extends ConfigCategory {
             + "is not able to fix them. This provides an option to suppress the exceptions printing out in the log.")
     private boolean disableFailingAdvancementDeserialization = true;
 
+    @Setting(value = "disable-pathfinding-chunk-loads", comment = "In vanilla, pathfinding may result in loading chunks.\n" +
+                    "You can disable that here, which may result in a\n" +
+                    "performance improvement. This may not work well\n" +
+                    "with mods."
+    )
+    private boolean disablePathFindingChunkLoads = false;
+
     public OptimizationCategory() {
         try {
             // Enabled by default on SpongeVanilla, disabled by default on SpongeForge.
@@ -208,4 +215,8 @@ public boolean disableFailingAdvancementDeserialization() {
         return this.disableFailingAdvancementDeserialization;
     }
 
+    public boolean disablePathFindingChunkLoads() {
+        return this.disablePathFindingChunkLoads;
+    }
+
 }

src/main/java/org/spongepowered/common/mixin/optimization/pathfinding/PathNavigateMixin_ChunkLoadOptimizations.java

@@ -0,0 +1,52 @@
+/*
+ * This file is part of Sponge, licensed under the MIT License (MIT).
+ *
+ * Copyright (c) SpongePowered <https://www.spongepowered.org>
+ * Copyright (c) contributors
+ *
+ * Permission is hereby granted, free of charge, to any person obtaining a copy
+ * of this software and associated documentation files (the "Software"), to deal
+ * in the Software without restriction, including without limitation the rights
+ * to use, copy, modify, merge, publish, distribute, sublicense, and/or sell
+ * copies of the Software, and to permit persons to whom the Software is
+ * furnished to do so, subject to the following conditions:
+ *
+ * The above copyright notice and this permission notice shall be included in
+ * all copies or substantial portions of the Software.
+ *
+ * THE SOFTWARE IS PROVIDED "AS IS", WITHOUT WARRANTY OF ANY KIND, EXPRESS OR
+ * IMPLIED, INCLUDING BUT NOT LIMITED TO THE WARRANTIES OF MERCHANTABILITY,
+ * FITNESS FOR A PARTICULAR PURPOSE AND NONINFRINGEMENT. IN NO EVENT SHALL THE
+ * AUTHORS OR COPYRIGHT HOLDERS BE LIABLE FOR ANY CLAIM, DAMAGES OR OTHER
+ * LIABILITY, WHETHER IN AN ACTION OF CONTRACT, TORT OR OTHERWISE, ARISING FROM,
+ * OUT OF OR IN CONNECTION WITH THE SOFTWARE OR THE USE OR OTHER DEALINGS IN
+ * THE SOFTWARE.
+ */
+package org.spongepowered.common.mixin.optimization.pathfinding;
+
+import net.minecraft.pathfinding.PathNavigate;
+import net.minecraft.util.math.BlockPos;
+import net.minecraft.world.World;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.Shadow;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Inject;
+import org.spongepowered.asm.mixin.injection.callback.CallbackInfoReturnable;
+
+@Mixin(value = PathNavigate.class, priority = 1500)
+public class PathNavigateMixin_ChunkLoadOptimizations {
+
+    @Shadow protected World world;
+
+    /**
+     * Check if a chunk is loaded before attempting to check the state of the block
+     * return false if the chunk is not loaded
+     */
+    @Inject(method = "canEntityStandOnPos", at = @At(value = "HEAD"), cancellable = true)
+    private void canEntityStandOnPos(BlockPos pos, CallbackInfoReturnable<Boolean> cir) {
+        if (!this.world.isBlockLoaded(pos)) {
+            cir.setReturnValue(false);
+        }
+    }
+
+}

src/main/java/org/spongepowered/common/mixin/plugin/OptimizationPlugin.java

@@ -139,6 +139,8 @@ public void postApply(String targetClassName, ClassNode targetClass, String mixi
                     OptimizationCategory::isUseActiveChunkForCollisions)
             .put("org.spongepowered.common.mixin.optimization.world.WorldServerMixin_UseActiveChunkForCollisions",
                     OptimizationCategory::isUseActiveChunkForCollisions)
+            .put("org.spongepowered.common.mixin.optimization.pathfinding.PathNavigateMixin_ChunkLoadOptimizations",
+                    OptimizationCategory::disablePathFindingChunkLoads)
             .build();
 
 }

src/main/resources/mixins.common.optimization.json

@@ -17,6 +17,7 @@
         "entity.item.EntityItemFrameMixin_MapOptimization",
         "item.ItemMapMixin_MapOptimization",
         "network.play.server.SPacketChunkDataMixin_Async_Lighting",
+        "pathfinding.PathNavigateMixin_ChunkLoadOptimizations",
         "server.MinecraftServerMixin_MapOptimization",
         "tileentity.TileEntityHopperMixin_HopperOptimization",
         "tileentity.TileEntityMixin_HopperOptimization",