Reuse starlight relighting code across versions (#2474)

worldedit-bukkit/src/main/java/com/fastasyncworldedit/bukkit/adapter/StarlightRelighter.java

@@ -0,0 +1,196 @@
+package com.fastasyncworldedit.bukkit.adapter;
+
+import com.fastasyncworldedit.core.extent.processor.lighting.NMSRelighter;
+import com.fastasyncworldedit.core.extent.processor.lighting.Relighter;
+import com.fastasyncworldedit.core.queue.IQueueExtent;
+import com.fastasyncworldedit.core.util.MathMan;
+import com.fastasyncworldedit.core.util.TaskManager;
+import com.sk89q.worldedit.internal.util.LogManagerCompat;
+import it.unimi.dsi.fastutil.longs.Long2ObjectLinkedOpenHashMap;
+import it.unimi.dsi.fastutil.longs.LongArraySet;
+import it.unimi.dsi.fastutil.longs.LongIterator;
+import it.unimi.dsi.fastutil.longs.LongSet;
+import org.apache.logging.log4j.Logger;
+import org.jetbrains.annotations.NotNull;
+
+import java.util.ArrayList;
+import java.util.HashSet;
+import java.util.List;
+import java.util.Set;
+import java.util.concurrent.CompletableFuture;
+import java.util.concurrent.locks.ReentrantLock;
+import java.util.function.Consumer;
+import java.util.function.IntConsumer;
+
+/**
+ * A base class for version-specific implementations of the starlight relighting mechanism
+ *
+ * @param <SERVER_LEVEL> the version-specific ServerLevel type
+ * @param <CHUNK_POS>    the version-specific ChunkPos type
+ * @since TODO
+ */
+public abstract class StarlightRelighter<SERVER_LEVEL, CHUNK_POS> implements Relighter {
+
+    protected static final Logger LOGGER = LogManagerCompat.getLogger();
+
+    private static final int CHUNKS_PER_BATCH = 1024; // 32 * 32
+    private static final int CHUNKS_PER_BATCH_SQRT_LOG2 = 5; // for shifting
+
+    private final ReentrantLock lock = new ReentrantLock();
+    private final Long2ObjectLinkedOpenHashMap<LongSet> regions = new Long2ObjectLinkedOpenHashMap<>();
+    private final ReentrantLock areaLock = new ReentrantLock();
+    private final NMSRelighter delegate;
+    protected final SERVER_LEVEL serverLevel;
+
+    protected StarlightRelighter(SERVER_LEVEL serverLevel, IQueueExtent<?> queue) {
+        this.serverLevel = serverLevel;
+        this.delegate = new NMSRelighter(queue);
+    }
+
+    protected Set<CHUNK_POS> convertChunkKeysToChunkPos(LongSet chunks) {
+        // convert from long keys to ChunkPos
+        Set<CHUNK_POS> coords = new HashSet<>();
+        LongIterator iterator = chunks.iterator();
+        while (iterator.hasNext()) {
+            coords.add(createChunkPos(iterator.nextLong()));
+        }
+        return coords;
+    }
+
+    protected abstract CHUNK_POS createChunkPos(long chunkKey);
+
+    protected abstract long asLong(int chunkX, int chunkZ);
+
+    protected abstract CompletableFuture<?> chunkLoadFuture(CHUNK_POS pos);
+
+    protected List<CompletableFuture<?>> chunkLoadFutures(Set<CHUNK_POS> coords) {
+        List<CompletableFuture<?>> futures = new ArrayList<>();
+        for (final CHUNK_POS coord : coords) {
+            futures.add(chunkLoadFuture(coord));
+        }
+        return futures;
+    }
+
+    @NotNull
+    protected IntConsumer postProcessCallback(Runnable andThen, Set<CHUNK_POS> coords) {
+        return i -> {
+            if (i != coords.size()) {
+                LOGGER.warn("Processed {} chunks instead of {}", i, coords.size());
+            }
+            // post process chunks on main thread
+            TaskManager.taskManager().task(() -> postProcessChunks(coords));
+            // call callback on our own threads
+            TaskManager.taskManager().async(andThen);
+        };
+    }
+
+    protected abstract void invokeRelight(
+            Set<CHUNK_POS> coords,
+            Consumer<CHUNK_POS> chunkCallback,
+            IntConsumer processCallback
+    );
+
+    protected abstract void postProcessChunks(Set<CHUNK_POS> coords);
+
+    /*
+     * Processes a set of chunks and runs an action afterwards.
+     * The action is run async, the chunks are partly processed on the main thread
+     * (as required by the server).
+     */
+    protected void fixLighting(LongSet chunks, Runnable andThen) {
+        Set<CHUNK_POS> coords = convertChunkKeysToChunkPos(chunks);
+        TaskManager.taskManager().task(() -> {
+            // trigger chunk load and apply ticket on main thread
+            List<CompletableFuture<?>> futures = chunkLoadFutures(coords);
+            // collect futures and trigger relight once all chunks are loaded
+            CompletableFuture.allOf(futures.toArray(new CompletableFuture[0])).thenAccept(v ->
+                    invokeRelight(
+                            coords,
+                            c -> {
+                            }, // no callback for single chunks required
+                            postProcessCallback(andThen, coords)
+                    )
+            );
+        });
+    }
+
+    @Override
+    public boolean addChunk(int cx, int cz, byte[] skipReason, int bitmask) {
+        areaLock.lock();
+        try {
+            long key = MathMan.pairInt(cx >> CHUNKS_PER_BATCH_SQRT_LOG2, cz >> CHUNKS_PER_BATCH_SQRT_LOG2);
+            // TODO probably submit here already if chunks.size == CHUNKS_PER_BATCH?
+            LongSet chunks = this.regions.computeIfAbsent(key, k -> new LongArraySet(CHUNKS_PER_BATCH >> 2));
+            chunks.add(asLong(cx, cz));
+        } finally {
+            areaLock.unlock();
+        }
+        return true;
+    }
+
+    /*
+     * This method is called "recursively", iterating and removing elements
+     * from the regions linked map. This way, chunks are loaded in batches to avoid
+     * OOMEs.
+     */
+
+    @Override
+    public void fixLightingSafe(boolean sky) {
+        this.areaLock.lock();
+        try {
+            if (regions.isEmpty()) {
+                return;
+            }
+            LongSet first = regions.removeFirst();
+            fixLighting(first, () -> fixLightingSafe(true));
+        } finally {
+            this.areaLock.unlock();
+        }
+    }
+
+    @Override
+    public void addLightUpdate(int x, int y, int z) {
+        this.delegate.addLightUpdate(x, y, z);
+    }
+
+    @Override
+    public void clear() {
+
+    }
+
+    @Override
+    public void removeLighting() {
+        this.delegate.removeLighting();
+    }
+
+    @Override
+    public void fixBlockLighting() {
+        fixLightingSafe(true);
+    }
+
+    @Override
+    public void fixSkyLighting() {
+        fixLightingSafe(true);
+    }
+
+    @Override
+    public boolean isEmpty() {
+        return true;
+    }
+
+    @Override
+    public ReentrantLock getLock() {
+        return this.lock;
+    }
+
+    @Override
+    public boolean isFinished() {
+        return false;
+    }
+
+    @Override
+    public void close() throws Exception {
+        fixLightingSafe(true);
+    }
+
+}