Cherry-pick WNA, minor changes. 1.16 VERY WIP

First noticed incident of operations ruining ChunkSections. Do not build and use this unless you're testing.

Rushed some of the changes, gotta sleep. Would be nice to get a review of this one from @mattbdev and @dordsor21

worldedit-core/src/main/java/com/sk89q/worldedit/internal/wna/WorldNativeAccess.java

@@ -0,0 +1,184 @@
+/*
+ * 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.internal.wna;
+
+import com.sk89q.jnbt.CompoundTag;
+import com.sk89q.worldedit.WorldEditException;
+import com.sk89q.worldedit.math.BlockVector3;
+import com.sk89q.worldedit.util.SideEffect;
+import com.sk89q.worldedit.util.SideEffectSet;
+import com.sk89q.worldedit.world.block.BaseBlock;
+import com.sk89q.worldedit.world.block.BlockState;
+import com.sk89q.worldedit.world.block.BlockStateHolder;
+
+import javax.annotation.Nullable;
+
+import static com.google.common.base.Preconditions.checkNotNull;
+
+/**
+ * Natively access and perform operations on the world.
+ *
+ * @param <NC> the native chunk type
+ * @param <NBS> the native block state type
+ * @param <NP> the native position type
+ */
+public interface WorldNativeAccess<NC, NBS, NP> {
+
+    default <B extends BlockStateHolder<B>> boolean setBlock(BlockVector3 position, B block, SideEffectSet sideEffects) throws WorldEditException {
+        checkNotNull(position);
+        checkNotNull(block);
+        setCurrentSideEffectSet(sideEffects);
+
+        int x = position.getBlockX();
+        int y = position.getBlockY();
+        int z = position.getBlockZ();
+
+        // First set the block
+        NC chunk = getChunk(x >> 4, z >> 4);
+        NP pos = getPosition(x, y, z);
+        NBS old = getBlockState(chunk, pos);
+        NBS newState = toNative(block.toImmutableState());
+        // change block prior to placing if it should be fixed
+        if (sideEffects.shouldApply(SideEffect.VALIDATION)) {
+            newState = getValidBlockForPosition(newState, pos);
+        }
+        NBS successState = setBlockState(chunk, pos, newState);
+        boolean successful = successState != null;
+
+        // Create the TileEntity
+        if (successful || old == newState) {
+            if (block instanceof BaseBlock) {
+                BaseBlock baseBlock = (BaseBlock) block;
+                CompoundTag tag = baseBlock.getNbtData();
+                if (tag != null) {
+                    tag = tag.createBuilder()
+                        .putString("id", baseBlock.getNbtId())
+                        .putInt("x", position.getX())
+                        .putInt("y", position.getY())
+                        .putInt("z", position.getZ())
+                        .build();
+                    // update if TE changed as well
+                    successful = updateTileEntity(pos, tag);
+                }
+            }
+        }
+
+        if (successful) {
+            if (sideEffects.getState(SideEffect.LIGHTING) == SideEffect.State.ON) {
+                updateLightingForBlock(pos);
+            }
+            markAndNotifyBlock(pos, chunk, old, newState, sideEffects);
+        }
+
+        return successful;
+    }
+
+    default void applySideEffects(BlockVector3 position, BlockState previousType, SideEffectSet sideEffectSet) {
+        setCurrentSideEffectSet(sideEffectSet);
+        NP pos = getPosition(position.getX(), position.getY(), position.getZ());
+        NC chunk = getChunk(position.getX() >> 4, position.getZ() >> 4);
+        NBS oldData = toNative(previousType);
+        NBS newData = getBlockState(chunk, pos);
+
+        if (sideEffectSet.getState(SideEffect.LIGHTING) == SideEffect.State.ON) {
+            updateLightingForBlock(pos);
+        }
+
+        markAndNotifyBlock(pos, chunk, oldData, newData, sideEffectSet);
+    }
+
+    // state-keeping functions for WNA
+    // may be thread-unsafe, as this is single-threaded code
+
+    /**
+     * Receive the current side-effect set from the high level call.
+     *
+     * This allows the implementation to branch on the side-effects internally.
+     *
+     * @param sideEffectSet the set of side-effects
+     */
+    default void setCurrentSideEffectSet(SideEffectSet sideEffectSet) {
+    }
+
+    // access functions
+
+    NC getChunk(int x, int z);
+
+    NBS toNative(BlockState state);
+
+    NBS getBlockState(NC chunk, NP position);
+
+    @Nullable
+    NBS setBlockState(NC chunk, NP position, NBS state);
+
+    NBS getValidBlockForPosition(NBS block, NP position);
+
+    NP getPosition(int x, int y, int z);
+
+    void updateLightingForBlock(NP position);
+
+    boolean updateTileEntity(NP position, CompoundTag tag);
+
+    void notifyBlockUpdate(NP position, NBS oldState, NBS newState);
+
+    boolean isChunkTicking(NC chunk);
+
+    void markBlockChanged(NP position);
+
+    void notifyNeighbors(NP pos, NBS oldState, NBS newState);
+
+    void updateNeighbors(NP pos, NBS oldState, NBS newState, int recursionLimit);
+
+    void onBlockStateChange(NP pos, NBS oldState, NBS newState);
+
+    /**
+     * This is a heavily modified function stripped from MC to apply worldedit-modifications.
+     *
+     * See Forge's World.markAndNotifyBlock
+     */
+    default void markAndNotifyBlock(NP pos, NC chunk, NBS oldState, NBS newState, SideEffectSet sideEffectSet) {
+        NBS blockState1 = getBlockState(chunk, pos);
+        if (blockState1 != newState) {
+            return;
+        }
+
+        // Remove redundant branches
+        if (isChunkTicking(chunk)) {
+            if (sideEffectSet.shouldApply(SideEffect.ENTITY_AI)) {
+                notifyBlockUpdate(pos, oldState, newState);
+            } else {
+                // If we want to skip entity AI, just mark the block for sending
+                markBlockChanged(pos);
+            }
+        }
+
+        if (sideEffectSet.shouldApply(SideEffect.NEIGHBORS)) {
+            notifyNeighbors(pos, oldState, newState);
+        }
+
+        // Make connection updates optional
+        if (sideEffectSet.shouldApply(SideEffect.VALIDATION)) {
+            updateNeighbors(pos, oldState, newState, 512);
+        }
+
+        onBlockStateChange(pos, oldState, newState);
+    }
+
+}

worldedit-core/src/main/java/com/sk89q/worldedit/internal/wna/package-info.java

@@ -0,0 +1,25 @@
+/*
+ * 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/>.
+ */
+
+/**
+ * "WNA", or WorldEdit Native Access.
+ *
+ * Contains internal helper functions for sharing code between platforms.
+ */
+package com.sk89q.worldedit.internal.wna;

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

@@ -24,9 +24,9 @@ import java.util.Locale;
 public enum SideEffect {
     LIGHTING(State.ON),
     NEIGHBORS(State.ON),
-    CONNECTIONS(State.ON),
+    VALIDATION(State.ON),
     ENTITY_AI(State.OFF),
-    PLUGIN_EVENTS(State.OFF);
+    EVENTS(State.OFF);
 
     private final String displayName;
     private final String description;