Implement UPDATE for Fabric (#1598)

* Implement UPDATE for Fabric

* Fix a minor threading problem

worldedit-fabric/src/main/java/com/sk89q/worldedit/fabric/FabricPlatform.java

@@ -216,7 +216,8 @@ public Map<Capability, Preference> getCapabilities() {
             SideEffect.VALIDATION,
             SideEffect.ENTITY_AI,
             SideEffect.LIGHTING,
-            SideEffect.NEIGHBORS
+            SideEffect.NEIGHBORS,
+            SideEffect.UPDATE
     );
 
     @Override

worldedit-fabric/src/main/java/com/sk89q/worldedit/fabric/internal/ExtendedChunk.java

@@ -0,0 +1,43 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.fabric.internal;
+
+import com.sk89q.worldedit.util.SideEffect;
+import net.minecraft.block.BlockState;
+import net.minecraft.util.math.BlockPos;
+import net.minecraft.world.chunk.Chunk;
+
+import javax.annotation.Nullable;
+
+public interface ExtendedChunk {
+    /**
+     * {@link Chunk#setBlockState(BlockPos, BlockState, boolean)} with the extra
+     * {@link SideEffect#UPDATE} flag.
+     *
+     * @param pos the position to set
+     * @param state the state to set
+     * @param moved I honestly have no idea and can't be bothered to investigate, we pass {@code
+     *     false}
+     * @param update the update flag, see side-effect for details
+     * @return the old block state, or {@code null} if unchanged
+     */
+    @Nullable
+    BlockState setBlockState(BlockPos pos, BlockState state, boolean moved, boolean update);
+}

worldedit-fabric/src/main/java/com/sk89q/worldedit/fabric/internal/FabricWorldNativeAccess.java

@@ -22,6 +22,8 @@
 import com.sk89q.worldedit.fabric.FabricAdapter;
 import com.sk89q.worldedit.internal.block.BlockStateIdAccess;
 import com.sk89q.worldedit.internal.wna.WorldNativeAccess;
+import com.sk89q.worldedit.util.SideEffect;
+import com.sk89q.worldedit.util.SideEffectSet;
 import net.minecraft.block.Block;
 import net.minecraft.block.BlockState;
 import net.minecraft.block.entity.BlockEntity;
@@ -41,6 +43,7 @@ public class FabricWorldNativeAccess implements WorldNativeAccess<WorldChunk, Bl
     private static final int NOTIFY = 2;
 
     private final WeakReference<World> world;
+    private SideEffectSet sideEffectSet;
 
     public FabricWorldNativeAccess(WeakReference<World> world) {
         this.world = world;
@@ -50,6 +53,11 @@ private World getWorld() {
         return Objects.requireNonNull(world.get(), "The reference to the world was lost");
     }
 
+    @Override
+    public void setCurrentSideEffectSet(SideEffectSet sideEffectSet) {
+        this.sideEffectSet = sideEffectSet;
+    }
+
     @Override
     public WorldChunk getChunk(int x, int z) {
         return getWorld().getChunk(x, z);
@@ -71,6 +79,11 @@ public BlockState getBlockState(WorldChunk chunk, BlockPos position) {
     @Nullable
     @Override
     public BlockState setBlockState(WorldChunk chunk, BlockPos position, BlockState state) {
+        if (chunk instanceof ExtendedChunk) {
+            return ((ExtendedChunk) chunk).setBlockState(
+                position, state, false, sideEffectSet.shouldApply(SideEffect.UPDATE)
+            );
+        }
         return chunk.setBlockState(position, state, false);
     }
 

worldedit-fabric/src/main/java/com/sk89q/worldedit/fabric/mixin/MixinWorldChunk.java

@@ -0,0 +1,74 @@
+/*
+ * WorldEdit, a Minecraft world manipulation toolkit
+ * Copyright (C) sk89q <http://www.sk89q.com>
+ * Copyright (C) WorldEdit team and contributors
+ *
+ * This program is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * This program is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU General Public License for more details.
+ *
+ * You should have received a copy of the GNU General Public License
+ * along with this program.  If not, see <https://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.fabric.mixin;
+
+import com.sk89q.worldedit.fabric.internal.ExtendedChunk;
+import net.minecraft.block.BlockState;
+import net.minecraft.server.MinecraftServer;
+import net.minecraft.util.math.BlockPos;
+import net.minecraft.world.World;
+import net.minecraft.world.chunk.Chunk;
+import net.minecraft.world.chunk.WorldChunk;
+import org.spongepowered.asm.mixin.Mixin;
+import org.spongepowered.asm.mixin.injection.At;
+import org.spongepowered.asm.mixin.injection.Redirect;
+import org.spongepowered.asm.mixin.injection.Slice;
+
+import javax.annotation.Nullable;
+
+@Mixin(WorldChunk.class)
+public abstract class MixinWorldChunk implements Chunk, ExtendedChunk {
+    private boolean shouldUpdate = true;
+
+    @Nullable
+    @Override
+    public BlockState setBlockState(BlockPos pos, BlockState state, boolean moved, boolean update) {
+        // save the state for the hook
+        shouldUpdate = update;
+        try {
+            return setBlockState(pos, state, moved);
+        } finally {
+            // restore natural mode
+            shouldUpdate = true;
+        }
+    }
+
+    @Redirect(
+        method = "setBlockState",
+        slice = @Slice(
+            from = @At(value = "INVOKE", target = "Lnet/minecraft/block/entity/BlockEntity;resetBlock()V")
+        ),
+        at = @At(value = "INVOKE", target = "Lnet/minecraft/block/BlockState;onBlockAdded(Lnet/minecraft/world/World;Lnet/minecraft/util/math/BlockPos;Lnet/minecraft/block/BlockState;Z)V", ordinal = 0)
+    )
+    public void setBlockStateHook(BlockState target, World world, BlockPos pos, BlockState old, boolean move) {
+        boolean localShouldUpdate;
+        MinecraftServer server = world.getServer();
+        if (server == null || Thread.currentThread() != server.getThread()) {
+            // We're not on the server thread for some reason, WorldEdit will never be here
+            // so we'll just ignore our flag
+            localShouldUpdate = true;
+        } else {
+            localShouldUpdate = shouldUpdate;
+        }
+        if (localShouldUpdate) {
+            target.onBlockAdded(world, pos, old, move);
+        }
+    }
+}

worldedit-fabric/src/main/resources/worldedit.mixins.json

@@ -6,6 +6,7 @@
         "MixinBiomeArray",
         "MixinServerPlayerEntity",
         "MixinMinecraftServer",
+        "MixinWorldChunk",
         "AccessorClientSettingsC2SPacket",
         "AccessorLevelProperties",
         "AccessorServerChunkManager"