Additional work towards 1.16 compatibility

- Very basic implementation of the SideEffects system. Will definitely need fine tuning for it to be functional, but is not considered a priority in my opinion.
- Minor changes to the World interface and World implementations related to the SideEffects system. Shouldn't be the cause of any new bugs but be on the lookout.
- Included debug in BukkitImplLoader.java to assist contributors in understanding what needs to be implemented for the adapter to load properly.

Still very WIP but we're a few steps closer. So far, this is coming along better than I anticipated. Hopefully we can keep the momentum.

config/checkstyle/checkstyle.xml

@@ -68,6 +68,6 @@
   </module>
   <!-- Validate that command annotations are formatted correctly -->
   <module name="RegexpMultiline">
-    <property name="format" value="^( +)@(Arg|Switch|Command)\(.*?\n\1 {5,}"/>
+    <property name="format" value="^( +)@(Arg|Switch|Command)\(.*?\r?\n\1 {5,}"/>
   </module>
 </module>

worldedit-bukkit/src/main/java/com/sk89q/worldedit/bukkit/BukkitServerInterface.java

@@ -19,6 +19,7 @@
 
 package com.sk89q.worldedit.bukkit;
 
+import com.google.common.collect.Sets;
 import com.sk89q.bukkit.util.CommandInfo;
 import com.sk89q.bukkit.util.CommandRegistration;
 import com.sk89q.worldedit.LocalConfiguration;
@@ -30,6 +31,7 @@ import com.sk89q.worldedit.extension.platform.Capability;
 import com.sk89q.worldedit.extension.platform.MultiUserPlatform;
 import com.sk89q.worldedit.extension.platform.Preference;
 import com.sk89q.worldedit.extension.platform.Watchdog;
+import com.sk89q.worldedit.util.SideEffect;
 import com.sk89q.worldedit.util.concurrency.LazyReference;
 import com.sk89q.worldedit.world.DataFixer;
 import com.sk89q.worldedit.world.registry.Registries;
@@ -44,8 +46,8 @@ import java.util.ArrayList;
 import java.util.Collection;
 import java.util.EnumMap;
 import java.util.List;
-import java.util.Locale;
 import java.util.Map;
+import java.util.Set;
 import java.util.stream.Collectors;
 import java.util.stream.Stream;
 
@@ -218,6 +220,18 @@ public class BukkitServerInterface implements MultiUserPlatform {
         return capabilities;
     }
 
+    private static final Set<SideEffect> SUPPORTED_SIDE_EFFECTS = Sets.immutableEnumSet(
+            SideEffect.NEIGHBORS
+    );
+
+    @Override
+    public Set<SideEffect> getSupportedSideEffects() {
+        if (plugin.getBukkitImplAdapter() != null) {
+            return plugin.getBukkitImplAdapter().getSupportedSideEffects();
+        }
+        return SUPPORTED_SIDE_EFFECTS;
+    }
+
     public void unregisterCommands() {
         dynamicCommands.unregisterCommands();
     }

worldedit-bukkit/src/main/java/com/sk89q/worldedit/bukkit/BukkitWorld.java

@@ -25,6 +25,7 @@ import com.boydti.fawe.Fawe;
 import com.boydti.fawe.beta.IChunkGet;
 import com.boydti.fawe.beta.implementation.packet.ChunkPacket;
 import com.sk89q.jnbt.CompoundTag;
+import com.google.common.collect.Sets;
 import com.sk89q.worldedit.EditSession;
 import com.sk89q.worldedit.WorldEdit;
 import com.sk89q.worldedit.WorldEditException;
@@ -38,6 +39,8 @@ import com.sk89q.worldedit.math.BlockVector3;
 import com.sk89q.worldedit.math.Vector3;
 import com.sk89q.worldedit.regions.Region;
 import com.sk89q.worldedit.util.Direction;
+import com.sk89q.worldedit.util.SideEffect;
+import com.sk89q.worldedit.util.SideEffectSet;
 import com.sk89q.worldedit.util.TreeGenerator;
 import com.sk89q.worldedit.world.AbstractWorld;
 import com.sk89q.worldedit.world.biome.BiomeType;
@@ -48,12 +51,7 @@ import com.sk89q.worldedit.world.weather.WeatherTypes;
 import io.papermc.lib.PaperLib;
 import java.lang.ref.WeakReference;
 import java.nio.file.Path;
-import java.util.ArrayList;
+import java.util.*;
-import java.util.EnumMap;
-import java.util.HashMap;
-import java.util.List;
-import java.util.Locale;
-import java.util.Map;
 import javax.annotation.Nullable;
 import org.bukkit.Effect;
 import org.bukkit.TreeType;
@@ -466,11 +464,11 @@ public class BukkitWorld extends AbstractWorld {
     }
 
     @Override
-    public <B extends BlockStateHolder<B>> boolean setBlock(BlockVector3 position, B block, boolean notifyAndLight) throws WorldEditException {
+    public <B extends BlockStateHolder<B>> boolean setBlock(BlockVector3 position, B block, SideEffectSet sideEffects) throws WorldEditException {
         BukkitImplAdapter adapter = WorldEditPlugin.getInstance().getBukkitImplAdapter();
         if (adapter != null) {
             try {
-                return adapter.setBlock(BukkitAdapter.adapt(getWorld(), position), block, notifyAndLight);
+                return adapter.setBlock(BukkitAdapter.adapt(getWorld(), position), block, sideEffects);
             } catch (Exception e) {
                 if (block instanceof BaseBlock && ((BaseBlock) block).getNbtData() != null) {
                     logger.warn("Tried to set a corrupt tile entity at " + position.toString());
@@ -478,12 +476,12 @@ public class BukkitWorld extends AbstractWorld {
                 }
                 e.printStackTrace();
                 Block bukkitBlock = getWorld().getBlockAt(position.getBlockX(), position.getBlockY(), position.getBlockZ());
-                bukkitBlock.setBlockData(BukkitAdapter.adapt(block), notifyAndLight);
+                bukkitBlock.setBlockData(BukkitAdapter.adapt(block), sideEffects.doesApplyAny());
                 return true;
             }
         } else {
             Block bukkitBlock = getWorld().getBlockAt(position.getBlockX(), position.getBlockY(), position.getBlockZ());
-            bukkitBlock.setBlockData(BukkitAdapter.adapt(block), false);
+            bukkitBlock.setBlockData(BukkitAdapter.adapt(block), sideEffects.doesApplyAny());
             return true;
         }
     }
@@ -499,14 +497,20 @@ public class BukkitWorld extends AbstractWorld {
     }
 
     @Override
-    public boolean notifyAndLightBlock(BlockVector3 position, com.sk89q.worldedit.world.block.BlockState previousType) throws WorldEditException {
+    public Set<SideEffect> applySideEffects(BlockVector3 position, com.sk89q.worldedit.world.block.BlockState previousType, SideEffectSet sideEffectSet) throws WorldEditException {
         BukkitImplAdapter adapter = WorldEditPlugin.getInstance().getBukkitImplAdapter();
         if (adapter != null) {
-            adapter.notifyAndLightBlock(BukkitAdapter.adapt(getWorld(), position), previousType);
+            adapter.applySideEffects(BukkitAdapter.adapt(getWorld(), position), previousType, sideEffectSet);
-            return true;
+            return Sets.intersection(
+                    adapter.getSupportedSideEffects(),
+                    sideEffectSet.getSideEffectsToApply()
+            );
         }
 
-        return false;
+        return Sets.intersection(
+                WorldEditPlugin.getInstance().getInternalPlatform().getSupportedSideEffects(),
+                sideEffectSet.getSideEffectsToApply()
+        );
     }
 
     @Override

worldedit-bukkit/src/main/java/com/sk89q/worldedit/bukkit/adapter/BukkitImplAdapter.java

@@ -34,6 +34,8 @@ import com.sk89q.worldedit.math.BlockVector3;
 import com.sk89q.worldedit.regions.Region;
 import com.sk89q.worldedit.registry.state.Property;
 import com.sk89q.worldedit.util.Direction;
+import com.sk89q.worldedit.util.SideEffect;
+import com.sk89q.worldedit.util.SideEffectSet;
 import com.sk89q.worldedit.world.DataFixer;
 import com.sk89q.worldedit.world.biome.BiomeType;
 import com.sk89q.worldedit.world.block.BaseBlock;
@@ -43,6 +45,7 @@ import com.sk89q.worldedit.world.block.BlockType;
 import com.sk89q.worldedit.world.registry.BlockMaterial;
 import java.util.Map;
 import java.util.OptionalInt;
+import java.util.Set;
 import javax.annotation.Nullable;
 import org.bukkit.Location;
 import org.bukkit.World;
@@ -99,19 +102,19 @@ public interface BukkitImplAdapter<T> extends IBukkitAdapter {
      *
      * @param location the location
      * @param state the block
-     * @param notifyAndLight notify and light if set
+     * @param sideEffectSet side effects to apply
      * @return true if a block was likely changed
      */
-    <B extends BlockStateHolder<B>> boolean setBlock(Location location, B state, boolean notifyAndLight);
+    boolean setBlock(Location location, BlockStateHolder<?> state, SideEffectSet sideEffectSet);
 
     /**
-     * Notifies the simulation that the block at the given location has
+     * Applies side effects on the given block.
-     * been changed and it must be re-lighted (and issue other events).
      *
      * @param position position of the block
      * @param previousType the type of the previous block that was there
+     * @param sideEffectSet side effects to apply
      */
-    void notifyAndLightBlock(Location position, BlockState previousType);
+    void applySideEffects(Location position, BlockState previousType, SideEffectSet sideEffectSet);
 
     /**
      * Get the state for the given entity.
@@ -186,6 +189,13 @@ public interface BukkitImplAdapter<T> extends IBukkitAdapter {
      */
     BaseItemStack adapt(ItemStack itemStack);
 
+    /**
+     * Get the {@link SideEffect}s that this adapter supports.
+     *
+     * @return The side effects that are supported
+     */
+    Set<SideEffect> getSupportedSideEffects();
+
     default OptionalInt getInternalBlockStateId(BlockData data) {
         // return OptionalInt.empty();
         return getInternalBlockStateId(BukkitAdapter.adapt(data));

worldedit-bukkit/src/main/java/com/sk89q/worldedit/bukkit/adapter/BukkitImplLoader.java

@@ -155,11 +155,20 @@ public class BukkitImplLoader {
      */
     public BukkitImplAdapter loadAdapter() throws AdapterLoadException {
         for (String className : adapterCandidates) {
+            System.out.println("Candidate: " + className);
             try {
                 Class<?> cls = Class.forName(className);
-                if (cls.isSynthetic()) continue;
+                if (cls.isSynthetic()){
+                    System.out.println(className + " is synthetic, continuing");
+                    continue;
+                }else{
+                    System.out.println(className + " is not synthetic");
+                }
                 if (BukkitImplAdapter.class.isAssignableFrom(cls)) {
+                    System.out.println(className + " is assignable from BukkitImplAdapter, returning");
                     return (BukkitImplAdapter) cls.newInstance();
+                }else{
+                    System.out.println(className + " is NOT assignable from BukkitImplAdapter, returning");
                 }
             } catch (ClassNotFoundException e) {
                 log.warn("Failed to load the Bukkit adapter class '" + className +
@@ -170,6 +179,8 @@ public class BukkitImplLoader {
             } catch (Throwable e) {
                 if (className.equals(customCandidate)) {
                     log.warn("Failed to load the Bukkit adapter class '" + className + "'", e);
+                }else{
+                    log.warn(className + " is not custom candidate.", e);
                 }
             }
         }

worldedit-bukkit/src/main/java/com/sk89q/worldedit/bukkit/adapter/IDelegateBukkitImplAdapter.java

@@ -12,6 +12,7 @@ import com.sk89q.worldedit.math.BlockVector3;
 import com.sk89q.worldedit.math.Vector3;
 import com.sk89q.worldedit.registry.state.Property;
 import com.sk89q.worldedit.util.Direction;
+import com.sk89q.worldedit.util.SideEffectSet;
 import com.sk89q.worldedit.world.DataFixer;
 import com.sk89q.worldedit.world.biome.BiomeType;
 import com.sk89q.worldedit.world.block.BaseBlock;
@@ -66,12 +67,7 @@ public interface IDelegateBukkitImplAdapter<T> extends BukkitImplAdapter<T> {
     }
 
     default <B extends BlockStateHolder<B>> boolean setBlock(Location location, B state, boolean notifyAndLight) {
-        return getParent().setBlock(location, state, notifyAndLight);
+        return getParent().setBlock(location, state, SideEffectSet.none());
-    }
-
-    @Override
-    default void notifyAndLightBlock(Location position, BlockState previousType) {
-        getParent().notifyAndLightBlock(position, previousType);
     }
 
     @Override

worldedit-bukkit/src/main/java/com/sk89q/worldedit/bukkit/adapter/impl/FAWE_Spigot_v1_14_R4.java

@@ -45,6 +45,8 @@ import com.sk89q.worldedit.entity.LazyBaseEntity;
 import com.sk89q.worldedit.math.BlockVector3;
 import com.sk89q.worldedit.regions.Region;
 import com.sk89q.worldedit.registry.state.Property;
+import com.sk89q.worldedit.util.SideEffect;
+import com.sk89q.worldedit.util.SideEffectSet;
 import com.sk89q.worldedit.world.biome.BiomeType;
 import com.sk89q.worldedit.world.biome.BiomeTypes;
 import com.sk89q.worldedit.world.block.BlockState;
@@ -71,6 +73,7 @@ import java.io.File;
 import java.io.IOException;
 import java.util.Map;
 import java.util.OptionalInt;
+import java.util.Set;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.Future;
 import java.util.function.Supplier;
@@ -148,6 +151,21 @@ public final class FAWE_Spigot_v1_14_R4 extends CachedBukkitAdapter implements I
         return state.toBaseBlock();
     }
 
+    @Override
+    public boolean setBlock(Location location, BlockStateHolder<?> state, SideEffectSet sideEffectSet) {
+        return this.setBlock(location.getChunk(), location.getBlockX(), location.getBlockY(), location.getBlockZ(), state, sideEffectSet.shouldApply(SideEffect.LIGHTING));
+    }
+
+    @Override
+    public void applySideEffects(Location position, BlockState previousType, SideEffectSet sideEffectSet) {
+        return; //TODO: properly implement SideEffects into FAWE
+    }
+
+    @Override
+    public Set<SideEffect> getSupportedSideEffects() {
+        return SideEffectSet.defaults().getSideEffectsToApply();
+    }
+
     @Override
     public <B extends BlockStateHolder<B>> boolean setBlock(Location location, B state, boolean notifyAndLight) {
         return this.setBlock(location.getChunk(), location.getBlockX(), location.getBlockY(), location.getBlockZ(), state, notifyAndLight);
@@ -292,11 +310,6 @@ public final class FAWE_Spigot_v1_14_R4 extends CachedBukkitAdapter implements I
         return material.getCraftBlockData();
     }
 
-    @Override
-    public void notifyAndLightBlock(Location position, BlockState previousType) {
-        this.setBlock(position.getChunk(), position.getBlockX(), position.getBlockY(), position.getBlockZ(), previousType, true);
-    }
-
     private MapChunkUtil_1_14 mapUtil = new MapChunkUtil_1_14();
 
     @Override

worldedit-bukkit/src/main/java/com/sk89q/worldedit/bukkit/adapter/impl/FAWE_Spigot_v1_15_R2.java

@@ -47,6 +47,8 @@ import com.sk89q.worldedit.entity.LazyBaseEntity;
 import com.sk89q.worldedit.math.BlockVector3;
 import com.sk89q.worldedit.regions.Region;
 import com.sk89q.worldedit.registry.state.Property;
+import com.sk89q.worldedit.util.SideEffect;
+import com.sk89q.worldedit.util.SideEffectSet;
 import com.sk89q.worldedit.world.biome.BiomeType;
 import com.sk89q.worldedit.world.biome.BiomeTypes;
 import com.sk89q.worldedit.world.block.BlockState;
@@ -73,6 +75,7 @@ import java.io.File;
 import java.io.IOException;
 import java.util.Map;
 import java.util.OptionalInt;
+import java.util.Set;
 import java.util.UUID;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.Future;
@@ -157,12 +160,27 @@ public final class FAWE_Spigot_v1_15_R2 extends CachedBukkitAdapter implements I
         return state.toBaseBlock();
     }
 
+    @Override
+    public boolean setBlock(Location location, BlockStateHolder<?> state, SideEffectSet sideEffectSet) {
+        return this.setBlock(location.getChunk(), location.getBlockX(), location.getBlockY(), location.getBlockZ(), state, sideEffectSet.shouldApply(SideEffect.LIGHTING));
+    }
+
+    @Override
+    public void applySideEffects(Location position, BlockState previousType, SideEffectSet sideEffectSet) {
+        return; //TODO: properly implement SideEffects into FAWE
+    }
+
+    @Override
+    public Set<SideEffect> getSupportedSideEffects() {
+        return SideEffectSet.defaults().getSideEffectsToApply();
+    }
+
     @Override
     public <B extends BlockStateHolder<B>> boolean setBlock(Location location, B state, boolean notifyAndLight) {
         return this.setBlock(location.getChunk(), location.getBlockX(), location.getBlockY(), location.getBlockZ(), state, notifyAndLight);
     }
 
-    public <B extends BlockStateHolder<B>> boolean setBlock(org.bukkit.Chunk chunk, int x, int y, int z, B state, boolean update) {
+    public boolean setBlock(org.bukkit.Chunk chunk, int x, int y, int z, BlockStateHolder state, boolean update) {
         CraftChunk craftChunk = (CraftChunk) chunk;
         Chunk nmsChunk = craftChunk.getHandle();
         World nmsWorld = nmsChunk.getWorld();
@@ -301,11 +319,6 @@ public final class FAWE_Spigot_v1_15_R2 extends CachedBukkitAdapter implements I
         return material.getCraftBlockData();
     }
 
-    @Override
-    public void notifyAndLightBlock(Location position, BlockState previousType) {
-        this.setBlock(position.getChunk(), position.getBlockX(), position.getBlockY(), position.getBlockZ(), previousType, true);
-    }
-
     private MapChunkUtil_1_15_2 mapUtil = new MapChunkUtil_1_15_2();
 
     @Override

worldedit-bukkit/src/main/java/com/sk89q/worldedit/bukkit/adapter/impl/FAWE_Spigot_v1_16_R1.java

@@ -47,6 +47,8 @@ import com.sk89q.worldedit.entity.LazyBaseEntity;
 import com.sk89q.worldedit.math.BlockVector3;
 import com.sk89q.worldedit.regions.Region;
 import com.sk89q.worldedit.registry.state.Property;
+import com.sk89q.worldedit.util.SideEffect;
+import com.sk89q.worldedit.util.SideEffectSet;
 import com.sk89q.worldedit.world.biome.BiomeType;
 import com.sk89q.worldedit.world.block.BlockState;
 import com.sk89q.worldedit.world.block.*;
@@ -72,6 +74,7 @@ import java.io.File;
 import java.io.IOException;
 import java.util.Map;
 import java.util.OptionalInt;
+import java.util.Set;
 import java.util.UUID;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.Future;
@@ -156,12 +159,27 @@ public final class FAWE_Spigot_v1_16_R1 extends CachedBukkitAdapter implements I
         return state.toBaseBlock();
     }
 
+    @Override
+    public boolean setBlock(Location location, BlockStateHolder<?> state, SideEffectSet sideEffectSet) {
+        return this.setBlock(location.getChunk(), location.getBlockX(), location.getBlockY(), location.getBlockZ(), state, sideEffectSet.shouldApply(SideEffect.LIGHTING));
+    }
+
+    @Override
+    public void applySideEffects(Location position, BlockState previousType, SideEffectSet sideEffectSet) {
+        return; //TODO: properly implement SideEffects into FAWE
+    }
+
+    @Override
+    public Set<SideEffect> getSupportedSideEffects() {
+        return SideEffectSet.defaults().getSideEffectsToApply();
+    }
+
     @Override
     public <B extends BlockStateHolder<B>> boolean setBlock(Location location, B state, boolean notifyAndLight) {
         return this.setBlock(location.getChunk(), location.getBlockX(), location.getBlockY(), location.getBlockZ(), state, notifyAndLight);
     }
 
-    public <B extends BlockStateHolder<B>> boolean setBlock(org.bukkit.Chunk chunk, int x, int y, int z, B state, boolean update) {
+    public boolean setBlock(org.bukkit.Chunk chunk, int x, int y, int z, BlockStateHolder state, boolean update) {
         CraftChunk craftChunk = (CraftChunk) chunk;
         Chunk nmsChunk = craftChunk.getHandle();
         World nmsWorld = nmsChunk.getWorld();
@@ -300,11 +318,6 @@ public final class FAWE_Spigot_v1_16_R1 extends CachedBukkitAdapter implements I
         return material.getCraftBlockData();
     }
 
-    @Override
-    public void notifyAndLightBlock(Location position, BlockState previousType) {
-        this.setBlock(position.getChunk(), position.getBlockX(), position.getBlockY(), position.getBlockZ(), previousType, true);
-    }
-
     private MapChunkUtil_1_16_1 mapUtil = new MapChunkUtil_1_16_1();
 
     @Override

worldedit-cli/src/main/java/com/sk89q/worldedit/cli/CLIPlatform.java

@@ -19,10 +19,12 @@
 
 package com.sk89q.worldedit.cli;
 
+import com.google.common.collect.ImmutableSet;
 import com.sk89q.worldedit.entity.Player;
 import com.sk89q.worldedit.extension.platform.AbstractPlatform;
 import com.sk89q.worldedit.extension.platform.Capability;
 import com.sk89q.worldedit.extension.platform.Preference;
+import com.sk89q.worldedit.util.SideEffect;
 import com.sk89q.worldedit.world.DataFixer;
 import com.sk89q.worldedit.world.World;
 import com.sk89q.worldedit.world.entity.EntityTypes;
@@ -33,6 +35,7 @@ import java.util.ArrayList;
 import java.util.EnumMap;
 import java.util.List;
 import java.util.Map;
+import java.util.Set;
 import java.util.Timer;
 import java.util.TimerTask;
 
@@ -153,6 +156,11 @@ class CLIPlatform extends AbstractPlatform {
         return capabilities;
     }
 
+    @Override
+    public Set<SideEffect> getSupportedSideEffects() {
+        return ImmutableSet.of();
+    }
+
     public void addWorld(World world) {
         worlds.add(world);
     }

worldedit-cli/src/main/java/com/sk89q/worldedit/cli/schematic/ClipboardWorld.java

@@ -19,6 +19,7 @@
 
 package com.sk89q.worldedit.cli.schematic;
 
+import com.google.common.collect.ImmutableSet;
 import com.sk89q.worldedit.EditSession;
 import com.sk89q.worldedit.MaxChangedBlocksException;
 import com.sk89q.worldedit.WorldEditException;
@@ -34,6 +35,8 @@ import com.sk89q.worldedit.math.BlockVector3;
 import com.sk89q.worldedit.math.Vector3;
 import com.sk89q.worldedit.regions.Region;
 import com.sk89q.worldedit.util.Location;
+import com.sk89q.worldedit.util.SideEffect;
+import com.sk89q.worldedit.util.SideEffectSet;
 import com.sk89q.worldedit.util.TreeGenerator;
 import com.sk89q.worldedit.world.AbstractWorld;
 import com.sk89q.worldedit.world.biome.BiomeType;
@@ -46,6 +49,7 @@ import java.io.FileOutputStream;
 import java.io.IOException;
 import java.util.List;
 import java.util.Locale;
+import java.util.Set;
 
 import javax.annotation.Nullable;
 
@@ -74,15 +78,14 @@ public class ClipboardWorld extends AbstractWorld implements Clipboard, CLIWorld
     }
 
     @Override
-    public <B extends BlockStateHolder<B>> boolean setBlock(BlockVector3 position, B block, boolean notifyAndLight)
+    public <B extends BlockStateHolder<B>> boolean setBlock(BlockVector3 position, B block, SideEffectSet sideEffects) throws WorldEditException {
-            throws WorldEditException {
         dirty = true;
         return clipboard.setBlock(position, block);
     }
 
     @Override
-    public boolean notifyAndLightBlock(BlockVector3 position, BlockState previousType) throws WorldEditException {
+    public Set<SideEffect> applySideEffects(BlockVector3 position, BlockState previousType, SideEffectSet sideEffectSet) throws WorldEditException {
-        return false;
+        return ImmutableSet.of();
     }
 
     @Override

worldedit-core/src/main/java/com/boydti/fawe/jnbt/anvil/MCAWorld.java

@@ -13,12 +13,16 @@ import com.sk89q.worldedit.extent.Extent;
 import com.sk89q.worldedit.math.BlockVector3;
 import com.sk89q.worldedit.math.Vector3;
 import com.sk89q.worldedit.regions.Region;
+import com.sk89q.worldedit.util.SideEffect;
+import com.sk89q.worldedit.util.SideEffectSet;
 import com.sk89q.worldedit.util.TreeGenerator;
 import com.sk89q.worldedit.world.AbstractWorld;
 import com.sk89q.worldedit.world.block.BlockState;
+import com.sk89q.worldedit.world.block.BlockStateHolder;
 
 import javax.annotation.Nullable;
 import java.io.File;
+import java.util.Set;
 
 import static com.google.common.base.Preconditions.checkArgument;
 
@@ -35,6 +39,11 @@ public class MCAWorld extends AbstractWorld {
         return path.getName();
     }
 
+    @Override
+    public <B extends BlockStateHolder<B>> boolean setBlock(BlockVector3 position, B block, SideEffectSet sideEffects) throws WorldEditException {
+        return false;
+    }
+
 
     @Override
     public boolean setTile(int x, int y, int z, CompoundTag tile) throws WorldEditException {
@@ -46,6 +55,11 @@ public class MCAWorld extends AbstractWorld {
         return false;
     }
 
+    @Override
+    public Set<SideEffect> applySideEffects(BlockVector3 position, BlockState previousType, SideEffectSet sideEffectSet) throws WorldEditException {
+        return SideEffectSet.none().getSideEffectsToApply();
+    }
+
     @Override
     public boolean clearContainerBlockContents(BlockVector3 position) {
         return false;

worldedit-core/src/main/java/com/boydti/fawe/object/brush/visualization/cfi/HeightMapMCAGenerator.java

@@ -29,10 +29,7 @@ import com.boydti.fawe.util.TextureUtil;
 import com.boydti.fawe.util.image.Drawable;
 import com.boydti.fawe.util.image.ImageViewer;
 import com.sk89q.jnbt.CompoundTag;
-import com.sk89q.worldedit.EditSession;
+import com.sk89q.worldedit.*;
-import com.sk89q.worldedit.LocalSession;
-import com.sk89q.worldedit.MaxChangedBlocksException;
-import com.sk89q.worldedit.WorldEditException;
 import com.sk89q.worldedit.blocks.BaseItemStack;
 import com.sk89q.worldedit.entity.Player;
 import com.sk89q.worldedit.extent.clipboard.Clipboard;
@@ -48,9 +45,7 @@ import com.sk89q.worldedit.math.transform.Transform;
 import com.sk89q.worldedit.regions.CuboidRegion;
 import com.sk89q.worldedit.regions.Region;
 import com.sk89q.worldedit.session.ClipboardHolder;
-import com.sk89q.worldedit.util.Identifiable;
+import com.sk89q.worldedit.util.*;
-import com.sk89q.worldedit.util.Location;
-import com.sk89q.worldedit.util.TreeGenerator;
 import com.sk89q.worldedit.world.World;
 import com.sk89q.worldedit.world.biome.BiomeType;
 import com.sk89q.worldedit.world.biome.BiomeTypes;
@@ -68,6 +63,7 @@ import java.lang.reflect.Field;
 import java.nio.file.Path;
 import java.util.Arrays;
 import java.util.List;
+import java.util.Set;
 import java.util.UUID;
 import java.util.concurrent.ThreadLocalRandom;
 import java.util.function.Supplier;
@@ -750,12 +746,24 @@ public class HeightMapMCAGenerator extends MCAWriter implements StreamChange, Dr
         return BlockVector3.at(getWidth() - 1, 255, getLength() - 1);
     }
 
+    @Override
+    public Set<SideEffect> applySideEffects(BlockVector3 position, BlockState previousType, SideEffectSet sideEffectSet)
+        throws WorldEditException{
+        return SideEffectSet.none().getSideEffectsToApply();
+    }
+
     @Override
     public <B extends BlockStateHolder<B>> boolean setBlock(BlockVector3 position, B block)
         throws WorldEditException {
         return setBlock(position.getBlockX(), position.getBlockY(), position.getBlockZ(), block);
     }
 
+    @Override
+    public <B extends BlockStateHolder<B>> boolean setBlock(BlockVector3 position, B block, SideEffectSet sideEffects)
+        throws WorldEditException {
+        return setBlock(position.getBlockX(), position.getBlockY(), position.getBlockZ(), block);
+    }
+
     private boolean setBlock(int x, int y, int z, char combined) {
         int index = z * getWidth() + x;
         if (index < 0 || index >= getArea()) {

worldedit-core/src/main/java/com/boydti/fawe/wrappers/WorldWrapper.java

@@ -24,9 +24,7 @@ import com.sk89q.worldedit.math.BlockVector2;
 import com.sk89q.worldedit.math.BlockVector3;
 import com.sk89q.worldedit.math.Vector3;
 import com.sk89q.worldedit.regions.Region;
-import com.sk89q.worldedit.util.Direction;
+import com.sk89q.worldedit.util.*;
-import com.sk89q.worldedit.util.Location;
-import com.sk89q.worldedit.util.TreeGenerator;
 import com.sk89q.worldedit.world.AbstractWorld;
 import com.sk89q.worldedit.world.World;
 import com.sk89q.worldedit.world.biome.BiomeType;
@@ -38,6 +36,7 @@ import com.sk89q.worldedit.world.weather.WeatherType;
 
 import javax.annotation.Nullable;
 import java.util.List;
+import java.util.Set;
 
 public class WorldWrapper extends AbstractWorld {
 
@@ -88,6 +87,12 @@ public class WorldWrapper extends AbstractWorld {
         return parent.useItem(position, item, face);
     }
 
+    @Override
+    public Set<SideEffect> applySideEffects(BlockVector3 position, BlockState previousType, SideEffectSet sideEffectSet)
+            throws WorldEditException{
+        return parent.applySideEffects(position, previousType, sideEffectSet);
+    }
+
     @Override
     public <B extends BlockStateHolder<B>> boolean setBlock(BlockVector3 position, B block, boolean notifyAndLight) throws WorldEditException {
         return parent.setBlock(position, block, notifyAndLight);
@@ -99,6 +104,11 @@ public class WorldWrapper extends AbstractWorld {
         return parent.setBlock(x, y, z, block);
     }
 
+    @Override
+    public <B extends BlockStateHolder<B>> boolean setBlock(BlockVector3 position, B block, SideEffectSet sideEffects) throws WorldEditException {
+        return parent.setBlock(position, block, sideEffects);
+    }
+
     @Override
     public boolean setTile(int x, int y, int z, CompoundTag tile) throws WorldEditException {
         return parent.setTile(x, y, z, tile);

worldedit-core/src/main/java/com/sk89q/worldedit/EditSession.java

@@ -117,6 +117,7 @@ import com.sk89q.worldedit.regions.shape.RegionShape;
 import com.sk89q.worldedit.regions.shape.WorldEditExpressionEnvironment;
 import com.sk89q.worldedit.util.Countable;
 import com.sk89q.worldedit.util.Direction;
+import com.sk89q.worldedit.util.SideEffectSet;
 import com.sk89q.worldedit.util.TreeGenerator;
 import com.sk89q.worldedit.util.eventbus.EventBus;
 import com.sk89q.worldedit.util.formatting.text.TranslatableComponent;
@@ -572,6 +573,20 @@ public class EditSession extends PassthroughExtent implements AutoCloseable {
         disableHistory(enabled);
     }
 
+    /**
+     * Set which block updates should occur.
+     *
+     * @param sideEffectSet side effects to enable
+     */
+    public void setSideEffectApplier(SideEffectSet sideEffectSet) {
+        //Do nothing; TODO: SideEffects currently not fully implemented in FAWE.
+    }
+
+    public SideEffectSet getSideEffectApplier() {
+        //Do nothing; TODO: SideEffects currently not fully implemented in FAWE.
+        return SideEffectSet.defaults();
+    }
+
     /**
      * Disable history (or re-enable)
      *

worldedit-core/src/main/java/com/sk89q/worldedit/LocalSession.java

@@ -72,6 +72,7 @@ import com.sk89q.worldedit.session.ClipboardHolder;
 import com.sk89q.worldedit.util.Countable;
 import com.sk89q.worldedit.util.HandSide;
 import com.sk89q.worldedit.util.Identifiable;
+import com.sk89q.worldedit.util.SideEffectSet;
 import com.sk89q.worldedit.world.World;
 import com.sk89q.worldedit.world.block.BaseBlock;
 import com.sk89q.worldedit.world.block.BlockState;
@@ -145,7 +146,7 @@ public class LocalSession implements TextureHolder {
     private transient Snapshot snapshotExperimental;
     private transient boolean hasCUISupport = false;
     private transient int cuiVersion = -1;
-    private transient boolean fastMode = false;
+    private transient SideEffectSet sideEffectSet = SideEffectSet.defaults();
     private transient Mask mask;
     private transient Mask sourceMask;
     private transient TextureUtil texture;
@@ -1494,7 +1495,7 @@ public class LocalSession implements TextureHolder {
             builder.blockBag(blockBag);
         }
         builder.command(command);
-        builder.fastmode(fastMode);
+        builder.fastmode(!this.sideEffectSet.doesApplyAny());
 
         editSession = builder.build();
 
@@ -1513,7 +1514,7 @@ public class LocalSession implements TextureHolder {
     }
 
     private void prepareEditingExtents(EditSession editSession, Actor actor) {
-        editSession.setFastMode(fastMode);
+        editSession.setSideEffectApplier(sideEffectSet);
         editSession.setReorderMode(reorderMode);
         if (editSession.getSurvivalExtent() != null) {
             editSession.getSurvivalExtent().setStripNbt(!actor.hasPermission("worldedit.setnbt"));
@@ -1521,13 +1522,32 @@ public class LocalSession implements TextureHolder {
         editSession.setTickingWatchdog(tickingWatchdog);
     }
 
+    /**
+     * Gets the side effect applier of this session.
+     *
+     * @return the side effect applier
+     */
+    public SideEffectSet getSideEffectSet() {
+        return this.sideEffectSet;
+    }
+
+    /**
+     * Sets the side effect applier for this session
+     *
+     * @param sideEffectSet the side effect applier
+     */
+    public void setSideEffectSet(SideEffectSet sideEffectSet) {
+        this.sideEffectSet = sideEffectSet;
+    }
+
     /**
      * Checks if the session has fast mode enabled.
      *
      * @return true if fast mode is enabled
      */
+    @Deprecated
     public boolean hasFastMode() {
-        return fastMode;
+        return !this.sideEffectSet.doesApplyAny();
     }
 
     /**
@@ -1535,8 +1555,9 @@ public class LocalSession implements TextureHolder {
      *
      * @param fastMode true if fast mode is enabled
      */
+    @Deprecated
     public void setFastMode(boolean fastMode) {
-        this.fastMode = fastMode;
+        this.sideEffectSet = fastMode ? SideEffectSet.none() : SideEffectSet.defaults();
     }
 
     /**

worldedit-core/src/main/java/com/sk89q/worldedit/command/GeneralCommands.java

@@ -49,10 +49,13 @@ import java.util.ArrayList;
 import com.sk89q.worldedit.extent.clipboard.Clipboard;
 import com.sk89q.worldedit.extension.platform.Capability;
 import com.sk89q.worldedit.function.mask.Mask;
+import com.sk89q.worldedit.util.SideEffect;
+import com.sk89q.worldedit.util.SideEffectSet;
 import com.sk89q.worldedit.util.formatting.component.PaginationBox;
+import com.sk89q.worldedit.util.formatting.component.SideEffectBox;
+import com.sk89q.worldedit.util.formatting.text.Component;
 import com.sk89q.worldedit.util.formatting.text.TextComponent;
 import com.sk89q.worldedit.util.formatting.text.format.TextColor;
-import com.sk89q.worldedit.util.formatting.text.Component;
 import com.sk89q.worldedit.world.World;
 import com.sk89q.worldedit.world.item.ItemType;
 import java.io.FileNotFoundException;
@@ -142,24 +145,62 @@ public class GeneralCommands {
 
     @Command(
         name = "/fast",
-        desc = "Toggle fast mode"
+        desc = "Toggle fast mode side effects"
     )
     @CommandPermissions("worldedit.fast")
     public void fast(Actor actor, LocalSession session,
-                     @Arg(desc = "The new fast mode state", def = "")
+                    @Arg(desc = "The side effect", def = "")
-                        Boolean fastMode) {
+                        SideEffect sideEffect,
-        boolean hasFastMode = session.hasFastMode();
+                    @Arg(desc = "The new side effect state", def = "")
-        if (fastMode != null && fastMode == hasFastMode) {
+                        SideEffect.State newState,
-            actor.printError(TranslatableComponent.of(fastMode ? "worldedit.fast.enabled.already" : "worldedit.fast.disabled.already"));
+                    @Switch(name = 'h', desc = "Show the info box")
-            return;
+                        boolean showInfoBox) throws WorldEditException {
+        if (sideEffect != null) {
+            SideEffect.State currentState = session.getSideEffectSet().getState(sideEffect);
+            if (newState != null && newState == currentState) {
+                if (!showInfoBox) {
+                    actor.printError(TranslatableComponent.of(
+                            "worldedit.fast.sideeffect.already-set",
+                            TranslatableComponent.of(sideEffect.getDisplayName()),
+                            TranslatableComponent.of(newState.getDisplayName())
+                    ));
+                }
+                return;
+            }
+
+            if (newState != null) {
+                session.setSideEffectSet(session.getSideEffectSet().with(sideEffect, newState));
+                if (!showInfoBox) {
+                    actor.printInfo(TranslatableComponent.of(
+                            "worldedit.fast.sideeffect.set",
+                            TranslatableComponent.of(sideEffect.getDisplayName()),
+                            TranslatableComponent.of(newState.getDisplayName())
+                    ));
+                }
+            } else {
+                actor.printInfo(TranslatableComponent.of(
+                        "worldedit.fast.sideeffect.get",
+                        TranslatableComponent.of(sideEffect.getDisplayName()),
+                        TranslatableComponent.of(currentState.getDisplayName())
+                ));
+            }
+        } else if (newState != null) {
+            SideEffectSet applier = session.getSideEffectSet();
+            for (SideEffect sideEffectEntry : SideEffect.values()) {
+                applier = applier.with(sideEffectEntry, newState);
+            }
+            session.setSideEffectSet(applier);
+            if (!showInfoBox) {
+                actor.printInfo(TranslatableComponent.of(
+                        "worldedit.fast.sideeffect.set-all",
+                        TranslatableComponent.of(newState.getDisplayName())
+                ));
+            }
         }
 
-        if (hasFastMode) {
+        if (sideEffect == null || showInfoBox) {
-            session.setFastMode(false);
+            SideEffectBox sideEffectBox = new SideEffectBox(session.getSideEffectSet());
-            actor.printInfo(TranslatableComponent.of("worldedit.fast.disabled"));
+            actor.print(sideEffectBox.create(1));
-        } else {
-            session.setFastMode(true);
-            actor.printInfo(TranslatableComponent.of("worldedit.fast.enabled"));
         }
     }
 

worldedit-core/src/main/java/com/sk89q/worldedit/command/argument/EnumConverter.java

@@ -23,6 +23,7 @@ import com.boydti.fawe.object.brush.scroll.Scroll;
 import com.google.common.collect.ImmutableSet;
 import com.sk89q.worldedit.EditSession;
 import com.sk89q.worldedit.command.util.HookMode;
+import com.sk89q.worldedit.util.SideEffect;
 import com.sk89q.worldedit.util.TreeGenerator;
 import org.enginehub.piston.CommandManager;
 import org.enginehub.piston.converter.ArgumentConverter;
@@ -30,6 +31,7 @@ import org.enginehub.piston.converter.MultiKeyConverter;
 import org.enginehub.piston.inject.Key;
 
 import javax.annotation.Nullable;
+
 import java.util.EnumSet;
 import java.util.Locale;
 import java.util.Set;
@@ -48,6 +50,11 @@ public final class EnumConverter {
             full(EditSession.ReorderMode.class,
                 r -> ImmutableSet.of(r.getDisplayName()),
                 null));
+        commandManager.registerConverter(Key.of(SideEffect.State.class),
+                MultiKeyConverter.from(
+                    EnumSet.of(SideEffect.State.OFF, SideEffect.State.ON),
+                    r -> ImmutableSet.of(r.name().toLowerCase(Locale.US)),
+                    null));
         commandManager.registerConverter(Key.of(HookMode.class),
             basic(HookMode.class));
         commandManager.registerConverter(Key.of(Scroll.Action.class),

worldedit-core/src/main/java/com/sk89q/worldedit/command/argument/SideEffectConverter.java

@@ -0,0 +1,75 @@
+/*
+ * 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 Lesser 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 Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.command.argument;
+
+import static org.enginehub.piston.converter.SuggestionHelper.limitByPrefix;
+
+import com.google.common.collect.ImmutableList;
+import com.sk89q.worldedit.WorldEdit;
+import com.sk89q.worldedit.command.util.EntityRemover;
+import com.sk89q.worldedit.util.SideEffect;
+import com.sk89q.worldedit.util.formatting.text.Component;
+import com.sk89q.worldedit.util.formatting.text.TextComponent;
+import org.enginehub.piston.CommandManager;
+import org.enginehub.piston.converter.ArgumentConverter;
+import org.enginehub.piston.converter.ConversionResult;
+import org.enginehub.piston.converter.FailedConversion;
+import org.enginehub.piston.converter.SuccessfulConversion;
+import org.enginehub.piston.inject.InjectedValueAccess;
+import org.enginehub.piston.inject.Key;
+
+import java.util.Collection;
+import java.util.List;
+import java.util.Locale;
+
+public class SideEffectConverter implements ArgumentConverter<SideEffect> {
+
+    public static void register(CommandManager commandManager) {
+        commandManager.registerConverter(Key.of(SideEffect.class), new SideEffectConverter());
+    }
+
+    private final TextComponent choices = TextComponent.of("any side effect");
+
+    private SideEffectConverter() {
+    }
+
+    private Collection<SideEffect> getSideEffects() {
+        return WorldEdit.getInstance().getPlatformManager().getSupportedSideEffects();
+    }
+
+    @Override
+    public Component describeAcceptableArguments() {
+        return choices;
+    }
+
+    @Override
+    public List<String> getSuggestions(String input, InjectedValueAccess context) {
+        return limitByPrefix(getSideEffects().stream().map(sideEffect -> sideEffect.name().toLowerCase(Locale.US)), input);
+    }
+
+    @Override
+    public ConversionResult<SideEffect> convert(String argument, InjectedValueAccess context) {
+        try {
+            return SuccessfulConversion.fromSingle(SideEffect.valueOf(argument.toUpperCase(Locale.US)));
+        } catch (Exception e) {
+            return FailedConversion.from(e);
+        }
+    }
+}

worldedit-core/src/main/java/com/sk89q/worldedit/extension/platform/Platform.java

@@ -21,14 +21,17 @@ package com.sk89q.worldedit.extension.platform;
 
 import com.sk89q.worldedit.LocalConfiguration;
 import com.sk89q.worldedit.entity.Player;
+import com.sk89q.worldedit.util.SideEffect;
 import com.sk89q.worldedit.world.DataFixer;
 import com.sk89q.worldedit.world.World;
 import com.sk89q.worldedit.world.registry.Registries;
 import org.enginehub.piston.CommandManager;
 
 import javax.annotation.Nullable;
+
 import java.util.List;
 import java.util.Map;
+import java.util.Set;
 
 /**
  * Represents a platform that WorldEdit has been implemented for.
@@ -174,4 +177,5 @@ public interface Platform {
      */
     Map<Capability, Preference> getCapabilities();
 
+    Set<SideEffect> getSupportedSideEffects();
 }

worldedit-core/src/main/java/com/sk89q/worldedit/extension/platform/PlatformCommandManager.java

@@ -94,6 +94,7 @@ import com.sk89q.worldedit.command.argument.ExpressionConverter;
 import com.sk89q.worldedit.command.argument.FactoryConverter;
 import com.sk89q.worldedit.command.argument.RegionFactoryConverter;
 import com.sk89q.worldedit.command.argument.RegistryConverter;
+import com.sk89q.worldedit.command.argument.SideEffectConverter;
 import com.sk89q.worldedit.command.argument.VectorConverter;
 import com.sk89q.worldedit.command.argument.WorldConverter;
 import com.sk89q.worldedit.command.argument.ZonedDateTimeConverter;
@@ -255,6 +256,7 @@ public final class PlatformCommandManager {
         RegionFactoryConverter.register(commandManager);
         WorldConverter.register(commandManager);
         ExpressionConverter.register(commandManager);
+        SideEffectConverter.register(commandManager);
 
         registerBindings(new ConsumeBindings(worldEdit, this));
         registerBindings(new PrimitiveBindings(worldEdit));

worldedit-core/src/main/java/com/sk89q/worldedit/extension/platform/PlatformManager.java

@@ -48,9 +48,11 @@ import com.sk89q.worldedit.event.platform.PlayerInputEvent;
 import com.sk89q.worldedit.math.Vector3;
 import com.sk89q.worldedit.session.request.Request;
 import com.sk89q.worldedit.util.Location;
+import com.sk89q.worldedit.util.SideEffect;
 import com.sk89q.worldedit.util.eventbus.Subscribe;
 import com.sk89q.worldedit.world.World;
 import java.util.ArrayList;
+import java.util.Collection;
 import java.util.EnumMap;
 import java.util.Iterator;
 import java.util.List;
@@ -304,6 +306,10 @@ public class PlatformManager {
         return queryCapability(Capability.CONFIGURATION).getConfiguration();
     }
 
+    public Collection<SideEffect> getSupportedSideEffects() {
+        return queryCapability(Capability.WORLD_EDITING).getSupportedSideEffects();
+    }
+
     @Subscribe
     public void handlePlatformReady(PlatformReadyEvent event) {
         choosePreferred();

worldedit-core/src/main/java/com/sk89q/worldedit/extent/buffer/ExtentBuffer.java

@@ -21,17 +21,16 @@ package com.sk89q.worldedit.extent.buffer;
 
 import static com.google.common.base.Preconditions.checkNotNull;
 
-import com.google.common.collect.Maps;
 import com.sk89q.worldedit.WorldEditException;
 import com.sk89q.worldedit.extent.AbstractBufferingExtent;
 import com.sk89q.worldedit.extent.Extent;
 import com.sk89q.worldedit.function.mask.Mask;
 import com.sk89q.worldedit.function.mask.Masks;
 import com.sk89q.worldedit.math.BlockVector3;
+import com.sk89q.worldedit.util.collection.BlockMap;
 import com.sk89q.worldedit.world.block.BaseBlock;
 import com.sk89q.worldedit.world.block.BlockStateHolder;
 import java.util.Map;
-import java.util.Optional;
 
 /**
  * Buffers changes to an {@link Extent} and allows retrieval of the changed blocks,
@@ -39,7 +38,7 @@ import java.util.Optional;
  */
 public class ExtentBuffer extends AbstractBufferingExtent {
 
-    private final Map<BlockVector3, BaseBlock> buffer = Maps.newHashMap();
+    private final Map<BlockVector3, BaseBlock> buffer = BlockMap.create();
     private final Mask mask;
 
     /**

worldedit-core/src/main/java/com/sk89q/worldedit/extent/reorder/ChunkBatchingExtent.java

@@ -19,7 +19,6 @@
 
 package com.sk89q.worldedit.extent.reorder;
 
-import com.google.common.collect.ImmutableSortedSet;
 import com.sk89q.worldedit.WorldEditException;
 import com.sk89q.worldedit.extent.AbstractBufferingExtent;
 import com.sk89q.worldedit.extent.Extent;

worldedit-core/src/main/java/com/sk89q/worldedit/extent/world/SideEffectExtent.java

@@ -27,67 +27,38 @@ import com.sk89q.worldedit.function.operation.Operation;
 import com.sk89q.worldedit.function.operation.RunContext;
 import com.sk89q.worldedit.math.BlockVector2;
 import com.sk89q.worldedit.math.BlockVector3;
+import com.sk89q.worldedit.util.SideEffect;
+import com.sk89q.worldedit.util.SideEffectSet;
+import com.sk89q.worldedit.util.collection.BlockMap;
 import com.sk89q.worldedit.world.World;
+import com.sk89q.worldedit.world.block.BlockState;
 import com.sk89q.worldedit.world.block.BlockStateHolder;
-import com.sk89q.worldedit.world.block.BlockTypes;
 
 import java.util.HashSet;
 import java.util.Iterator;
-import java.util.List;
+import java.util.Map;
 import java.util.Set;
 
 /**
- * Implements "fast mode" which may skip physics, lighting, etc.
+ * An extent that sets blocks in the world, with a {@link SideEffectSet}.
  */
-public class FastModeExtent extends AbstractDelegateExtent {
+public class SideEffectExtent extends AbstractDelegateExtent {
 
     private final World world;
-    private final Set<BlockVector3> positions = new HashSet<>();
+    private final Map<BlockVector3, BlockState> positions = BlockMap.create();
     private final Set<BlockVector2> dirtyChunks = new HashSet<>();
-    private boolean enabled = true;
+    private SideEffectSet sideEffectSet = SideEffectSet.defaults();
     private boolean postEditSimulation;
 
-    /**
-     * Create a new instance with fast mode enabled.
-     *
-     * @param world the world
-     */
-    public FastModeExtent(World world) {
-        this(world, true);
-    }
-
     /**
      * Create a new instance.
      *
      * @param world the world
-     * @param enabled true to enable fast mode
      */
-    public FastModeExtent(World world, boolean enabled) {
+    public SideEffectExtent(World world) {
         super(world);
         checkNotNull(world);
         this.world = world;
-        this.enabled = enabled;
-        if (enabled) {
-            this.postEditSimulation = true;
-        }
-    }
-
-    /**
-     * Return whether fast mode is enabled.
-     *
-     * @return true if fast mode is enabled
-     */
-    public boolean isEnabled() {
-        return enabled;
-    }
-
-    /**
-     * Set fast mode enable status.
-     *
-     * @param enabled true to enable fast mode
-     */
-    public void setEnabled(boolean enabled) {
-        this.enabled = enabled;
     }
 
     public boolean isPostEditSimulationEnabled() {
@@ -98,26 +69,28 @@ public class FastModeExtent extends AbstractDelegateExtent {
         this.postEditSimulation = enabled;
     }
 
+    public SideEffectSet getSideEffectSet() {
+        return this.sideEffectSet;
+    }
+
+    public void setSideEffectSet(SideEffectSet sideEffectSet) {
+        this.sideEffectSet = sideEffectSet;
+    }
+
     @Override
     public <B extends BlockStateHolder<B>> boolean setBlock(BlockVector3 location, B block) throws WorldEditException {
-        if (enabled || postEditSimulation) {
+        if (sideEffectSet.getState(SideEffect.LIGHTING) == SideEffect.State.DELAYED) {
             dirtyChunks.add(BlockVector2.at(location.getBlockX() >> 4, location.getBlockZ() >> 4));
-
-            if (world.setBlock(location, block, false)) {
-                if (!enabled && postEditSimulation) {
-                    positions.add(location);
-                }
-                return true;
-            }
-
-            return false;
-        } else {
-            return world.setBlock(location, block, true);
         }
+        if (postEditSimulation) {
+            positions.put(location, world.getBlock(location));
+        }
+
+        return world.setBlock(location, block, postEditSimulation ? SideEffectSet.none() : sideEffectSet);
     }
 
     public boolean commitRequired() {
-        return enabled || postEditSimulation;
+        return postEditSimulation || !dirtyChunks.isEmpty();
     }
 
     @Override
@@ -132,11 +105,11 @@ public class FastModeExtent extends AbstractDelegateExtent {
                     world.fixAfterFastMode(dirtyChunks);
                 }
 
-                if (!enabled && postEditSimulation) {
+                if (postEditSimulation) {
-                    Iterator<BlockVector3> positionIterator = positions.iterator();
+                    Iterator<Map.Entry<BlockVector3, BlockState>> positionIterator = positions.entrySet().iterator();
                     while (run.shouldContinue() && positionIterator.hasNext()) {
-                        BlockVector3 position = positionIterator.next();
+                        Map.Entry<BlockVector3, BlockState> position = positionIterator.next();
-                        world.notifyAndLightBlock(position, BlockTypes.AIR.getDefaultState());
+                        world.applySideEffects(position.getKey(), position.getValue(), sideEffectSet);
                         positionIterator.remove();
                     }
 
@@ -151,5 +124,4 @@ public class FastModeExtent extends AbstractDelegateExtent {
             }
         };
     }
-
 }

worldedit-core/src/main/java/com/sk89q/worldedit/util/SideEffect.java

@@ -0,0 +1,68 @@
+/*
+ * 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 Lesser 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 Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.util;
+
+import java.util.Locale;
+
+public enum SideEffect {
+    LIGHTING(State.ON),
+    NEIGHBORS(State.ON),
+    CONNECTIONS(State.ON),
+    ENTITY_AI(State.OFF),
+    PLUGIN_EVENTS(State.OFF);
+
+    private final String displayName;
+    private final String description;
+    private final State defaultValue;
+
+    SideEffect(State defaultValue) {
+        this.displayName = "worldedit.sideeffect." + this.name().toLowerCase(Locale.US);
+        this.description = "worldedit.sideeffect." + this.name().toLowerCase(Locale.US) + ".description";
+        this.defaultValue = defaultValue;
+    }
+
+    public String getDisplayName() {
+        return this.displayName;
+    }
+
+    public String getDescription() {
+        return this.description;
+    }
+
+    public State getDefaultValue() {
+        return this.defaultValue;
+    }
+
+    public enum State {
+        OFF,
+        ON,
+        DELAYED;
+
+        private final String displayName;
+
+        State() {
+            this.displayName = "worldedit.sideeffect.state." + this.name().toLowerCase(Locale.US);
+        }
+
+        public String getDisplayName() {
+            return this.displayName;
+        }
+    }
+}

worldedit-core/src/main/java/com/sk89q/worldedit/util/SideEffectSet.java

@@ -0,0 +1,94 @@
+/*
+ * 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 Lesser 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 Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.util;
+
+import com.google.common.collect.ImmutableMap;
+import com.google.common.collect.Maps;
+
+import java.util.Arrays;
+import java.util.EnumMap;
+import java.util.Map;
+import java.util.Set;
+import java.util.function.Function;
+import java.util.stream.Collectors;
+
+public class SideEffectSet {
+    private static final SideEffectSet DEFAULT = new SideEffectSet(
+            Arrays.stream(SideEffect.values()).collect(Collectors.toMap(Function.identity(), SideEffect::getDefaultValue))
+    );
+    private static final SideEffectSet NONE = new SideEffectSet();
+
+    private final Map<SideEffect, SideEffect.State> sideEffects;
+    private final Set<SideEffect> appliedSideEffects;
+    private final boolean appliesAny;
+
+    private SideEffectSet() {
+        this(ImmutableMap.of());
+    }
+
+    public SideEffectSet(Map<SideEffect, SideEffect.State> sideEffects) {
+        this.sideEffects = Maps.immutableEnumMap(sideEffects);
+
+        appliedSideEffects = sideEffects.entrySet()
+                .stream()
+                .filter(entry -> entry.getValue() != SideEffect.State.OFF)
+                .map(Map.Entry::getKey)
+                .collect(Collectors.toSet());
+        appliesAny = !appliedSideEffects.isEmpty();
+    }
+
+    public SideEffectSet with(SideEffect sideEffect, SideEffect.State state) {
+        Map<SideEffect, SideEffect.State> entries = this.sideEffects.isEmpty() ? Maps.newEnumMap(SideEffect.class) : new EnumMap<>(this.sideEffects);
+        entries.put(sideEffect, state);
+        return new SideEffectSet(entries);
+    }
+
+    public boolean doesApplyAny() {
+        return this.appliesAny;
+    }
+
+    public SideEffect.State getState(SideEffect effect) {
+        return sideEffects.getOrDefault(effect, effect.getDefaultValue());
+    }
+
+    /**
+     * Gets whether this side effect is not off.
+     *
+     * This returns whether it is either delayed or on.
+     *
+     * @param effect The side effect
+     * @return Whether it should apply
+     */
+    public boolean shouldApply(SideEffect effect) {
+        return getState(effect) != SideEffect.State.OFF;
+    }
+
+    public Set<SideEffect> getSideEffectsToApply() {
+        return this.appliedSideEffects;
+    }
+
+    public static SideEffectSet defaults() {
+        return DEFAULT;
+    }
+
+    public static SideEffectSet none() {
+        return NONE;
+    }
+}

worldedit-core/src/main/java/com/sk89q/worldedit/util/formatting/component/SideEffectBox.java

@@ -0,0 +1,88 @@
+/*
+ * 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 Lesser 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 Lesser General Public License
+ * for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with this program. If not, see <http://www.gnu.org/licenses/>.
+ */
+
+package com.sk89q.worldedit.util.formatting.component;
+
+import com.sk89q.worldedit.WorldEdit;
+import com.sk89q.worldedit.util.SideEffect;
+import com.sk89q.worldedit.util.SideEffectSet;
+import com.sk89q.worldedit.util.formatting.text.Component;
+import com.sk89q.worldedit.util.formatting.text.TextComponent;
+import com.sk89q.worldedit.util.formatting.text.TranslatableComponent;
+import com.sk89q.worldedit.util.formatting.text.event.ClickEvent;
+import com.sk89q.worldedit.util.formatting.text.event.HoverEvent;
+import com.sk89q.worldedit.util.formatting.text.format.TextColor;
+
+import java.util.Comparator;
+import java.util.List;
+import java.util.Locale;
+import java.util.stream.Collectors;
+
+public class SideEffectBox extends PaginationBox {
+
+    private static List<SideEffect> sideEffects;
+
+    private SideEffectSet sideEffectSet;
+
+    private static List<SideEffect> getSideEffects() {
+        if (sideEffects == null) {
+            sideEffects = WorldEdit.getInstance().getPlatformManager().getSupportedSideEffects()
+                    .stream()
+                    .sorted(Comparator.comparing(Enum::name))
+                    .collect(Collectors.toList());
+        }
+
+        return sideEffects;
+    }
+
+    public SideEffectBox(SideEffectSet sideEffectSet) {
+        super("Side Effects");
+
+        this.sideEffectSet = sideEffectSet;
+    }
+
+    private static final SideEffect.State[] SHOWN_VALUES = {SideEffect.State.OFF, SideEffect.State.ON};
+
+    @Override
+    public Component getComponent(int number) {
+        SideEffect effect = getSideEffects().get(number);
+        SideEffect.State state = this.sideEffectSet.getState(effect);
+
+        TextComponent.Builder builder = TextComponent.builder();
+        builder = builder.append(TranslatableComponent.of(effect.getDisplayName(), TextColor.YELLOW)
+                .hoverEvent(HoverEvent.of(HoverEvent.Action.SHOW_TEXT, TranslatableComponent.of(effect.getDescription()))));
+        for (SideEffect.State uiState : SHOWN_VALUES) {
+            builder = builder.append(TextComponent.space());
+            builder = builder.append(TranslatableComponent.of(uiState.getDisplayName(), uiState == state ? TextColor.WHITE : TextColor.GRAY)
+                    .clickEvent(ClickEvent.runCommand("//fast -h " + effect.name().toLowerCase(Locale.US) + " " + uiState.name().toLowerCase(Locale.US)))
+                    .hoverEvent(HoverEvent.showText(uiState == state
+                            ? TranslatableComponent.of("worldedit.sideeffect.box.current")
+                            : TranslatableComponent.of("worldedit.sideeffect.box.change-to", TranslatableComponent.of(uiState.getDisplayName()))
+                    ))
+            );
+        }
+
+        return builder.build();
+    }
+
+    @Override
+    public int getComponentsSize() {
+        return getSideEffects().size();
+    }
+}

worldedit-core/src/main/java/com/sk89q/worldedit/world/AbstractWorld.java

@@ -32,6 +32,7 @@ import com.sk89q.worldedit.math.BlockVector2;
 import com.sk89q.worldedit.math.BlockVector3;
 import com.sk89q.worldedit.math.Vector3;
 import com.sk89q.worldedit.util.Direction;
+import com.sk89q.worldedit.util.SideEffectSet;
 import com.sk89q.worldedit.world.block.BlockStateHolder;
 import com.sk89q.worldedit.world.weather.WeatherType;
 import com.sk89q.worldedit.world.block.BlockType;
@@ -57,7 +58,7 @@ public abstract class AbstractWorld implements World {
 
     @Override
     public final <B extends BlockStateHolder<B>> boolean setBlock(BlockVector3 pt, B block) throws WorldEditException {
-        return setBlock(pt, block, true);
+        return setBlock(pt, block, SideEffectSet.defaults());
     }
 
     @Override

worldedit-core/src/main/java/com/sk89q/worldedit/world/NullWorld.java

@@ -23,6 +23,7 @@ import com.boydti.fawe.beta.IChunkGet;
 import com.boydti.fawe.beta.implementation.packet.ChunkPacket;
 import com.boydti.fawe.beta.implementation.blocks.NullChunkGet;
 import com.sk89q.jnbt.CompoundTag;
+import com.google.common.collect.ImmutableSet;
 import com.sk89q.worldedit.EditSession;
 import com.sk89q.worldedit.MaxChangedBlocksException;
 import com.sk89q.worldedit.WorldEditException;
@@ -35,6 +36,8 @@ import com.sk89q.worldedit.math.BlockVector3;
 import com.sk89q.worldedit.math.Vector3;
 import com.sk89q.worldedit.regions.Region;
 import com.sk89q.worldedit.util.Location;
+import com.sk89q.worldedit.util.SideEffect;
+import com.sk89q.worldedit.util.SideEffectSet;
 import com.sk89q.worldedit.util.TreeGenerator.TreeType;
 import com.sk89q.worldedit.world.biome.BiomeType;
 import com.sk89q.worldedit.world.biome.BiomeTypes;
@@ -48,6 +51,7 @@ import com.sk89q.worldedit.world.weather.WeatherTypes;
 import javax.annotation.Nullable;
 import java.util.Collections;
 import java.util.List;
+import java.util.Set;
 
 /**
  * A null implementation of {@link World} that drops all changes and
@@ -71,13 +75,14 @@ public class NullWorld extends AbstractWorld {
     }
 
     @Override
-    public <B extends BlockStateHolder<B>> boolean setBlock(BlockVector3 position, B block, boolean notifyAndLight) throws WorldEditException {
+    public <B extends BlockStateHolder<B>> boolean setBlock(BlockVector3 position, B block, SideEffectSet sideEffects) throws WorldEditException {
         return false;
     }
 
     @Override
-    public boolean notifyAndLightBlock(BlockVector3 position, BlockState previousType) throws WorldEditException {
+    public Set<SideEffect> applySideEffects(BlockVector3 position, BlockState previousType, SideEffectSet sideEffectSet)
-        return false;
+            throws WorldEditException {
+        return ImmutableSet.of();
     }
 
     @Override

worldedit-core/src/main/java/com/sk89q/worldedit/world/World.java

@@ -37,15 +37,19 @@ import com.sk89q.worldedit.math.Vector3;
 import com.sk89q.worldedit.regions.Region;
 import com.sk89q.worldedit.registry.Keyed;
 import com.sk89q.worldedit.util.Direction;
+import com.sk89q.worldedit.util.SideEffect;
+import com.sk89q.worldedit.util.SideEffectSet;
 import com.sk89q.worldedit.util.TreeGenerator;
 import com.sk89q.worldedit.world.block.BlockState;
 import com.sk89q.worldedit.world.block.BlockStateHolder;
 import com.sk89q.worldedit.world.block.BlockType;
 import com.sk89q.worldedit.world.weather.WeatherType;
 
-import javax.annotation.Nullable;
 import java.nio.file.Path;
 import java.util.Locale;
+import java.util.Set;
+
+import javax.annotation.Nullable;
 
 /**
  * Represents a world (dimension).
@@ -112,10 +116,28 @@ public interface World extends Extent, Keyed, IChunkCache<IChunkGet> {
      * @param notifyAndLight true to to notify and light
      * @return true if the block was successfully set (return value may not be accurate)
      */
+    @Deprecated
     default <B extends BlockStateHolder<B>> boolean setBlock(BlockVector3 position, B block, boolean notifyAndLight) throws WorldEditException {
-        return setBlock(position, block);
+        return setBlock(position, block, notifyAndLight ? SideEffectSet.defaults() : SideEffectSet.none());
     }
 
+    /**
+     * Similar to {@link Extent#setBlock(BlockVector3, BlockStateHolder)} but a
+     * {@code sideEffects} parameter indicates which side effects should be applied
+     * to the block. This includes block updates, lighting, and others. See {@link SideEffect}
+     * for a full list.
+     *
+     * <p>Not all implementations support all side effects. Use
+     * {@link Platform#getSupportedSideEffects()} for a list of supported side effects.
+     * Non-supported side effects will be ignored.</p>
+     *
+     * @param position position of the block
+     * @param block block to set
+     * @param sideEffects which side effects to perform
+     * @return true if the block was successfully set (return value may not be accurate)
+     */
+    <B extends BlockStateHolder<B>> boolean setBlock(BlockVector3 position, B block, SideEffectSet sideEffects) throws WorldEditException;
+
     /**
      * Notifies the simulation that the block at the given location has
      * been changed and it must be re-lighted (and issue other events).
@@ -124,7 +146,20 @@ public interface World extends Extent, Keyed, IChunkCache<IChunkGet> {
      * @param previousType the type of the previous block that was there
      * @return true if the block was successfully notified
      */
-    boolean notifyAndLightBlock(BlockVector3 position, BlockState previousType) throws WorldEditException;
+    @Deprecated
+    default boolean notifyAndLightBlock(BlockVector3 position, BlockState previousType) throws WorldEditException {
+        return !applySideEffects(position, previousType, SideEffectSet.defaults()).isEmpty();
+    }
+
+    /**
+     * Applies a set of side effects on the given block.
+     *
+     * @param position position of the block
+     * @param previousType the type of the previous block that was there
+     * @param sideEffectSet which side effects to perform
+     * @return a set of side effects that were applied
+     */
+    Set<SideEffect> applySideEffects(BlockVector3 position, BlockState previousType, SideEffectSet sideEffectSet) throws WorldEditException;
 
     /**
      * Get the light level at the given block.

worldedit-core/src/main/resources/lang/strings.json

@@ -210,6 +210,10 @@
     "worldedit.fast.enabled": "Fast mode enabled. Lighting in the affected chunks may be wrong and/or you may need to rejoin to see changes.",
     "worldedit.fast.disabled.already": "Fast mode already disabled.",
     "worldedit.fast.enabled.already": "Fast mode already enabled.",
+    "worldedit.fast.sideeffect.set": "Side effect \"{0}\" set to {1}",
+    "worldedit.fast.sideeffect.get": "Side effect \"{0}\" is set to {1}",
+    "worldedit.fast.sideeffect.already-set": "Side effect \"{0}\" is already {1}",
+    "worldedit.fast.sideeffect.set-all": "All side effects set to {0}",
     "worldedit.reorder.current": "The reorder mode is {0}",
     "worldedit.reorder.set": "The reorder mode is now {0}",
     "worldedit.gmask.disabled": "Global mask disabled.",
@@ -494,6 +498,22 @@
     "worldedit.selection.sphere.explain.secondary": "Radius set to {0}.",
     "worldedit.selection.sphere.explain.secondary-defined": "Radius set to {0} ({1}).",
 
+    "worldedit.sideeffect.lighting": "Lighting",
+    "worldedit.sideeffect.lighting.description": "Updates block lighting",
+    "worldedit.sideeffect.neighbors": "Neighbors",
+    "worldedit.sideeffect.neighbors.description": "Notifies nearby blocks of changes",
+    "worldedit.sideeffect.connections": "Connections",
+    "worldedit.sideeffect.connections.description": "Updates connections for blocks like fences",
+    "worldedit.sideeffect.entity_ai": "Entity AI",
+    "worldedit.sideeffect.entity_ai.description": "Updates Entity AI paths for the block changes",
+    "worldedit.sideeffect.plugin_events": "Plugin Events",
+    "worldedit.sideeffect.plugin_events.description": "Tells other plugins/mods about these changes when applicable",
+    "worldedit.sideeffect.state.on": "On",
+    "worldedit.sideeffect.state.delayed": "Delayed",
+    "worldedit.sideeffect.state.off": "Off",
+    "worldedit.sideeffect.box.current": "Current",
+    "worldedit.sideeffect.box.change-to": "Click to set to {0}",
+
     "worldedit.help.command-not-found": "The command '{0}' could not be found.",
     "worldedit.help.no-subcommands": "'{0}' has no sub-commands. (Maybe '{1}' is for a parameter?)",
     "worldedit.help.subcommand-not-found": "The sub-command '{0}' under '{1}' could not be found.",

worldedit-fabric/build.gradle.kts

@@ -61,16 +61,12 @@ tasks.named<Copy>("processResources") {
     }
 }
 
-<<<<<<< HEAD
-addJarManifest(includeClasspath = true)
-=======
 tasks.named<Jar>("jar") {
     manifest {
         attributes("Class-Path" to CLASSPATH,
                    "WorldEdit-Version" to project.version)
     }
 }
->>>>>>> 18a55bc14... Add new experimental snapshot API (#524)
 
 tasks.named<ShadowJar>("shadowJar") {
     archiveClassifier.set("dist-dev")

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

@@ -19,6 +19,7 @@
 
 package com.sk89q.worldedit.fabric;
 
+import com.google.common.collect.Sets;
 import com.sk89q.worldedit.command.util.PermissionCondition;
 import com.sk89q.worldedit.entity.Player;
 import com.sk89q.worldedit.extension.platform.AbstractPlatform;
@@ -27,13 +28,13 @@ import com.sk89q.worldedit.extension.platform.Capability;
 import com.sk89q.worldedit.extension.platform.MultiUserPlatform;
 import com.sk89q.worldedit.extension.platform.Preference;
 import com.sk89q.worldedit.extension.platform.Watchdog;
+import com.sk89q.worldedit.util.SideEffect;
 import com.sk89q.worldedit.world.DataFixer;
 import com.sk89q.worldedit.world.World;
 import com.sk89q.worldedit.world.registry.Registries;
 import net.minecraft.SharedConstants;
 import net.minecraft.server.MinecraftServer;
 import net.minecraft.server.PlayerManager;
-import net.minecraft.server.dedicated.DedicatedServer;
 import net.minecraft.server.dedicated.MinecraftDedicatedServer;
 import net.minecraft.server.network.ServerPlayerEntity;
 import net.minecraft.server.world.ServerWorld;
@@ -200,6 +201,18 @@ class FabricPlatform extends AbstractPlatform implements MultiUserPlatform {
         return capabilities;
     }
 
+    private static final Set<SideEffect> SUPPORTED_SIDE_EFFECTS = Sets.immutableEnumSet(
+            SideEffect.CONNECTIONS,
+            SideEffect.ENTITY_AI,
+            SideEffect.LIGHTING,
+            SideEffect.NEIGHBORS
+    );
+
+    @Override
+    public Set<SideEffect> getSupportedSideEffects() {
+        return SUPPORTED_SIDE_EFFECTS;
+    }
+
     @Override
     public Collection<Actor> getConnectedUsers() {
         List<Actor> users = new ArrayList<>();

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

@@ -24,6 +24,7 @@ import static com.google.common.base.Preconditions.checkNotNull;
 import com.google.common.cache.CacheBuilder;
 import com.google.common.cache.CacheLoader;
 import com.google.common.cache.LoadingCache;
+import com.google.common.collect.Sets;
 import com.google.common.io.Files;
 import com.sk89q.jnbt.CompoundTag;
 import com.sk89q.worldedit.EditSession;
@@ -42,6 +43,8 @@ import com.sk89q.worldedit.regions.CuboidRegion;
 import com.sk89q.worldedit.regions.Region;
 import com.sk89q.worldedit.util.Direction;
 import com.sk89q.worldedit.util.Location;
+import com.sk89q.worldedit.util.SideEffect;
+import com.sk89q.worldedit.util.SideEffectSet;
 import com.sk89q.worldedit.util.TreeGenerator.TreeType;
 import com.sk89q.worldedit.world.AbstractWorld;
 import com.sk89q.worldedit.world.biome.BiomeType;
@@ -61,6 +64,7 @@ import net.minecraft.item.ItemStack;
 import net.minecraft.item.ItemUsageContext;
 import net.minecraft.server.MinecraftServer;
 import net.minecraft.server.WorldGenerationProgressListener;
+import net.minecraft.server.world.ChunkHolder;
 import net.minecraft.server.world.ServerChunkManager;
 import net.minecraft.server.world.ServerWorld;
 import net.minecraft.util.ActionResult;
@@ -71,6 +75,7 @@ import net.minecraft.util.math.BlockPos;
 import net.minecraft.util.math.ChunkPos;
 import net.minecraft.world.World;
 import net.minecraft.world.WorldSaveHandler;
+import net.minecraft.world.biome.DefaultBiomeFeatures;
 import net.minecraft.world.chunk.Chunk;
 import net.minecraft.world.chunk.ChunkManager;
 import net.minecraft.world.chunk.ChunkStatus;
@@ -104,6 +109,7 @@ import java.util.Locale;
 import java.util.Optional;
 import java.util.OptionalInt;
 import java.util.Random;
+import java.util.Set;
 import java.util.concurrent.ExecutionException;
 import java.util.concurrent.ThreadLocalRandom;
 import java.util.stream.Collectors;
@@ -185,8 +191,44 @@ public class FabricWorld extends AbstractWorld {
         return null;
     }
 
+    public void markAndNotifyBlock(World world, BlockPos pos, @Nullable WorldChunk worldChunk, net.minecraft.block.BlockState blockState,
+            net.minecraft.block.BlockState state, SideEffectSet sideEffectSet) {
+        Block block = state.getBlock();
+        net.minecraft.block.BlockState blockState2 = world.getBlockState(pos);
+        if (blockState2 == state) {
+            if (blockState != blockState2) {
+                world.checkBlockRerender(pos, blockState, blockState2);
+            }
+
+            if (world.isClient || worldChunk.getLevelType() != null && worldChunk.getLevelType().isAfter(ChunkHolder.LevelType.TICKING)) {
+                if (sideEffectSet.shouldApply(SideEffect.ENTITY_AI)) {
+                    world.updateListeners(pos, blockState, state, UPDATE | NOTIFY);
+                } else {
+                    // If we want to skip entity AI, just call the chunk dirty flag.
+                    ((ServerChunkManager) world.getChunkManager()).markForUpdate(pos);
+                }
+            }
+
+            if (!world.isClient && sideEffectSet.shouldApply(SideEffect.NEIGHBORS)) {
+                world.updateNeighbors(pos, blockState.getBlock());
+                if (state.hasComparatorOutput()) {
+                    world.updateHorizontalAdjacent(pos, block);
+                }
+            }
+
+            if (sideEffectSet.shouldApply(SideEffect.CONNECTIONS)) {
+                blockState.method_11637(world, pos, 2);
+                state.updateNeighborStates(world, pos, 2);
+                state.method_11637(world, pos, 2);
+            }
+
+            // This is disabled for other platforms, but keep it for mods.
+            world.onBlockChanged(pos, blockState, blockState2);
+        }
+    }
+
     @Override
-    public <B extends BlockStateHolder<B>> boolean setBlock(BlockVector3 position, B block, boolean notifyAndLight) throws WorldEditException {
+    public <B extends BlockStateHolder<B>> boolean setBlock(BlockVector3 position, B block, SideEffectSet sideEffects) throws WorldEditException {
         checkNotNull(position);
         checkNotNull(block);
 
@@ -196,7 +238,7 @@ public class FabricWorld extends AbstractWorld {
         int z = position.getBlockZ();
 
         // First set the block
-        Chunk chunk = world.getChunk(x >> 4, z >> 4);
+        WorldChunk chunk = world.getChunk(x >> 4, z >> 4);
         BlockPos pos = new BlockPos(x, y, z);
         net.minecraft.block.BlockState old = chunk.getBlockState(pos);
         OptionalInt stateId = BlockStateIdAccess.getBlockStateId(block.toImmutableState());
@@ -221,26 +263,27 @@ public class FabricWorld extends AbstractWorld {
             }
         }
 
-        if (successful && notifyAndLight) {
+        if (successful) {
-            world.getChunkManager().getLightingProvider().enqueueLightUpdate(pos);
+            if (sideEffects.getState(SideEffect.LIGHTING) == SideEffect.State.ON) {
-            world.scheduleBlockRender(pos, old, newState);
+                world.getChunkManager().getLightingProvider().checkBlock(pos);
-            world.updateListeners(pos, old, newState, UPDATE | NOTIFY);
-            world.updateNeighbors(pos, newState.getBlock());
-            if (old.hasComparatorOutput()) {
-                world.updateHorizontalAdjacent(pos, newState.getBlock());
             }
+            markAndNotifyBlock(world, pos, chunk, old, newState, sideEffects);
         }
 
         return successful;
     }
 
     @Override
-    public boolean notifyAndLightBlock(BlockVector3 position, BlockState previousType) throws WorldEditException {
+    public Set<SideEffect> applySideEffects(BlockVector3 position, BlockState previousType, SideEffectSet sideEffectSet) throws WorldEditException {
         BlockPos pos = new BlockPos(position.getX(), position.getY(), position.getZ());
-        net.minecraft.block.BlockState state = getWorld().getBlockState(pos);
+        net.minecraft.block.BlockState oldData = FabricAdapter.adapt(previousType);
-        getWorld().updateListeners(pos, FabricAdapter.adapt(previousType), state, 1 | 2);
+        net.minecraft.block.BlockState newData = getWorld().getBlockState(pos);
-        getWorld().updateNeighbors(pos, state.getBlock());
+
-        return true;
+        if (sideEffectSet.getState(SideEffect.LIGHTING) == SideEffect.State.ON) {
+            getWorld().getChunkManager().getLightingProvider().checkBlock(pos);
+        }
+        markAndNotifyBlock(getWorld(), pos, null, oldData, newData, sideEffectSet); // Update
+        return Sets.intersection(FabricWorldEdit.inst.getPlatform().getSupportedSideEffects(), sideEffectSet.getSideEffectsToApply());
     }
 
     @Override

worldedit-forge/build.gradle.kts

@@ -77,7 +77,12 @@ tasks.named<Copy>("processResources") {
     }
 }
 
-addJarManifest(includeClasspath = false)
+tasks.named<Jar>("jar") {
+    manifest {
+        attributes("Class-Path" to CLASSPATH,
+                "WorldEdit-Version" to project.version)
+    }
+}
 
 tasks.named<ShadowJar>("shadowJar") {
     dependencies {

worldedit-forge/src/main/java/com/sk89q/worldedit/forge/ForgePlatform.java

@@ -27,6 +27,7 @@ import com.sk89q.worldedit.extension.platform.Actor;
 import com.sk89q.worldedit.extension.platform.Capability;
 import com.sk89q.worldedit.extension.platform.MultiUserPlatform;
 import com.sk89q.worldedit.extension.platform.Preference;
+import com.sk89q.worldedit.util.SideEffect;
 import com.sk89q.worldedit.world.DataFixer;
 import com.sk89q.worldedit.world.World;
 import com.sk89q.worldedit.world.registry.Registries;
@@ -206,6 +207,18 @@ class ForgePlatform extends AbstractPlatform implements MultiUserPlatform {
         return capabilities;
     }
 
+    private static final Set<SideEffect> SUPPORTED_SIDE_EFFECTS = Sets.immutableEnumSet(
+            SideEffect.CONNECTIONS,
+            SideEffect.ENTITY_AI,
+            SideEffect.LIGHTING,
+            SideEffect.NEIGHBORS
+    );
+
+    @Override
+    public Set<SideEffect> getSupportedSideEffects() {
+        return SUPPORTED_SIDE_EFFECTS;
+    }
+
     @Override
     public Collection<Actor> getConnectedUsers() {
         List<Actor> users = new ArrayList<>();

worldedit-forge/src/main/java/com/sk89q/worldedit/forge/ForgeWorld.java

@@ -19,6 +19,8 @@
 
 package com.sk89q.worldedit.forge;
 
+import static com.google.common.base.Preconditions.checkNotNull;
+
 import com.google.common.cache.CacheBuilder;
 import com.google.common.cache.CacheLoader;
 import com.google.common.cache.LoadingCache;
@@ -96,13 +98,13 @@ import net.minecraft.world.gen.feature.SwampTreeFeature;
 import net.minecraft.world.gen.feature.TallTaigaTreeFeature;
 import net.minecraft.world.gen.feature.TreeFeature;
 
+import net.minecraft.world.server.ChunkHolder;
 import net.minecraft.world.server.ServerChunkProvider;
 import net.minecraft.world.server.ServerWorld;
 import net.minecraft.world.storage.SaveHandler;
 import net.minecraft.world.storage.WorldInfo;
 import net.minecraftforge.common.DimensionManager;
 
-import javax.annotation.Nullable;
 import java.io.File;
 import java.io.IOException;
 import java.lang.ref.WeakReference;
@@ -117,7 +119,7 @@ import java.util.concurrent.ExecutionException;
 import java.util.concurrent.ThreadLocalRandom;
 import java.util.stream.Collectors;
 
-import static com.google.common.base.Preconditions.checkNotNull;
+import javax.annotation.Nullable;
 
 /**
  * An adapter to Minecraft worlds for WorldEdit.
@@ -130,7 +132,7 @@ public class ForgeWorld extends AbstractWorld {
     private static final net.minecraft.block.BlockState JUNGLE_LOG = Blocks.JUNGLE_LOG.getDefaultState();
     private static final net.minecraft.block.BlockState JUNGLE_LEAF = Blocks.JUNGLE_LEAVES.getDefaultState().with(LeavesBlock.PERSISTENT, Boolean.TRUE);
     private static final net.minecraft.block.BlockState JUNGLE_SHRUB = Blocks.OAK_LEAVES.getDefaultState().with(LeavesBlock.PERSISTENT, Boolean.TRUE);
-    
+
     private final WeakReference<World> worldRef;
 
     /**
@@ -192,8 +194,51 @@ public class ForgeWorld extends AbstractWorld {
         return null;
     }
 
+    /**
+     * This is a heavily modified function stripped from MC to apply worldedit-modifications.
+     *
+     * @see World#markAndNotifyBlock
+     */
+    public void markAndNotifyBlock(World world, BlockPos pos, @Nullable Chunk chunk, net.minecraft.block.BlockState blockstate,
+            net.minecraft.block.BlockState newState, SideEffectSet sideEffectSet) {
+        Block block = newState.getBlock();
+        net.minecraft.block.BlockState blockstate1 = world.getBlockState(pos);
+        if (blockstate1 == newState) {
+            if (blockstate != blockstate1) {
+                world.markBlockRangeForRenderUpdate(pos, blockstate, blockstate1);
+            }
+
+            // Remove redundant branches
+            if (world.isRemote || chunk == null || chunk.getLocationType().isAtLeast(ChunkHolder.LocationType.TICKING)) {
+                if (sideEffectSet.shouldApply(SideEffect.ENTITY_AI)) {
+                    world.notifyBlockUpdate(pos, blockstate, newState, UPDATE | NOTIFY);
+                } else {
+                    // If we want to skip entity AI, just call the chunk dirty flag.
+                    ((ServerChunkProvider) world.getChunkProvider()).markBlockChanged(pos);
+                }
+            }
+
+            if (!world.isRemote && sideEffectSet.shouldApply(SideEffect.NEIGHBORS)) {
+                world.notifyNeighbors(pos, blockstate.getBlock());
+                if (newState.hasComparatorInputOverride()) {
+                    world.updateComparatorOutputLevel(pos, block);
+                }
+            }
+
+            // Make connection updates optional
+            if (sideEffectSet.shouldApply(SideEffect.CONNECTIONS)) {
+                blockstate.updateDiagonalNeighbors(world, pos, 2);
+                newState.updateNeighbors(world, pos, 2);
+                newState.updateDiagonalNeighbors(world, pos, 2);
+            }
+
+            // This is disabled for other platforms, but keep it for mods.
+            world.onBlockStateChange(pos, blockstate, blockstate1);
+        }
+    }
+
     @Override
-    public <B extends BlockStateHolder<B>> boolean setBlock(BlockVector3 position, B block, boolean notifyAndLight) throws WorldEditException {
+    public <B extends BlockStateHolder<B>> boolean setBlock(BlockVector3 position, B block, SideEffectSet sideEffects) throws WorldEditException {
         checkNotNull(position);
         checkNotNull(block);
 
@@ -224,19 +269,27 @@ public class ForgeWorld extends AbstractWorld {
             }
         }
 
-        if (successful && notifyAndLight) {
+        if (successful) {
-            world.getChunkProvider().getLightManager().checkBlock(pos);
+            if (sideEffects.getState(SideEffect.LIGHTING) == SideEffect.State.ON) {
-            world.markAndNotifyBlock(pos, chunk, old, newState, UPDATE | NOTIFY);
+                world.getChunkProvider().getLightManager().checkBlock(pos);
+            }
+            markAndNotifyBlock(world, pos, chunk, old, newState, sideEffects);
         }
 
         return successful;
     }
 
     @Override
-    public boolean notifyAndLightBlock(BlockVector3 position, BlockState previousType) throws WorldEditException {
+    public Set<SideEffect> applySideEffects(BlockVector3 position, BlockState previousType, SideEffectSet sideEffectSet) throws WorldEditException {
         BlockPos pos = new BlockPos(position.getX(), position.getY(), position.getZ());
-        getWorld().notifyBlockUpdate(pos, ForgeAdapter.adapt(previousType), getWorld().getBlockState(pos), 1 | 2);
+        net.minecraft.block.BlockState oldData = ForgeAdapter.adapt(previousType);
-        return true;
+        net.minecraft.block.BlockState newData = getWorld().getBlockState(pos);
+
+        if (sideEffectSet.getState(SideEffect.LIGHTING) == SideEffect.State.ON) {
+            getWorld().getChunkProvider().getLightManager().checkBlock(pos);
+        }
+        markAndNotifyBlock(getWorld(), pos, null, oldData, newData, sideEffectSet); // Update
+        return Sets.intersection(ForgeWorldEdit.inst.getPlatform().getSupportedSideEffects(), sideEffectSet.getSideEffectsToApply());
     }
 
     @Override

worldedit-sponge/src/main/java/com/sk89q/worldedit/sponge/SpongePlatform.java

@@ -20,6 +20,8 @@
 package com.sk89q.worldedit.sponge;
 
 import com.google.common.collect.ImmutableList;
+import com.google.common.collect.ImmutableSet;
+import com.google.common.collect.Lists;
 import com.sk89q.worldedit.WorldEdit;
 import com.sk89q.worldedit.entity.Player;
 import com.sk89q.worldedit.event.platform.CommandEvent;
@@ -31,6 +33,7 @@ import com.sk89q.worldedit.extension.platform.MultiUserPlatform;
 import com.sk89q.worldedit.extension.platform.Preference;
 import com.sk89q.worldedit.internal.command.CommandUtil;
 import com.sk89q.worldedit.sponge.config.SpongeConfiguration;
+import com.sk89q.worldedit.util.SideEffect;
 import com.sk89q.worldedit.world.World;
 import com.sk89q.worldedit.world.registry.Registries;
 import org.enginehub.piston.Command;
@@ -50,6 +53,7 @@ import java.util.EnumMap;
 import java.util.List;
 import java.util.Map;
 import java.util.Optional;
+import java.util.Set;
 
 import static java.util.stream.Collectors.toList;
 
@@ -192,6 +196,11 @@ class SpongePlatform extends AbstractPlatform implements MultiUserPlatform {
         return capabilities;
     }
 
+    @Override
+    public Set<SideEffect> getSupportedSideEffects() {
+        return ImmutableSet.of();
+    }
+
     @Override
     public Collection<Actor> getConnectedUsers() {
         List<Actor> users = new ArrayList<>();