fix: allow queues to not generate chunks (#4599)

- initially apply to regenallroads
 - additionally add a 10s timeout for requesting a chunk before resubmitting it to the queue
 - addresses #4310

Author: dordsor21

Bukkit/src/main/java/com/plotsquared/bukkit/queue/BukkitChunkCoordinator.java

@@ -30,6 +30,8 @@
 import com.sk89q.worldedit.math.BlockVector2;
 import com.sk89q.worldedit.world.World;
 import io.papermc.lib.PaperLib;
+import org.apache.logging.log4j.LogManager;
+import org.apache.logging.log4j.Logger;
 import org.bukkit.Bukkit;
 import org.bukkit.Chunk;
 import org.bukkit.plugin.Plugin;
@@ -41,6 +43,7 @@
 import java.util.List;
 import java.util.Queue;
 import java.util.concurrent.LinkedBlockingQueue;
+import java.util.concurrent.TimeUnit;
 import java.util.concurrent.atomic.AtomicInteger;
 import java.util.function.Consumer;
 
@@ -55,6 +58,8 @@
  **/
 public final class BukkitChunkCoordinator extends ChunkCoordinator {
 
+    private static final Logger LOGGER = LogManager.getLogger("PlotSquared/" + BukkitChunkCoordinator.class.getSimpleName());
+
     private final List<ProgressSubscriber> progressSubscribers = new LinkedList<>();
 
     private final Queue<BlockVector2> requestedChunks;
@@ -70,6 +75,7 @@ public final class BukkitChunkCoordinator extends ChunkCoordinator {
     private final AtomicInteger expectedSize;
     private final AtomicInteger loadingChunks = new AtomicInteger();
     private final boolean forceSync;
+    private final boolean shouldGen;
 
     private int batchSize;
     private PlotSquaredTask task;
@@ -87,7 +93,8 @@ private BukkitChunkCoordinator(
             @Assisted final @NonNull Consumer<Throwable> throwableConsumer,
             @Assisted("unloadAfter") final boolean unloadAfter,
             @Assisted final @NonNull Collection<ProgressSubscriber> progressSubscribers,
-            @Assisted("forceSync") final boolean forceSync
+            @Assisted("forceSync") final boolean forceSync,
+            @Assisted("shouldGen") final boolean shouldGen
     ) {
         this.requestedChunks = new LinkedBlockingQueue<>(requestedChunks);
         this.availableChunks = new LinkedBlockingQueue<>();
@@ -103,6 +110,7 @@ private BukkitChunkCoordinator(
         this.bukkitWorld = Bukkit.getWorld(world.getName());
         this.progressSubscribers.addAll(progressSubscribers);
         this.forceSync = forceSync;
+        this.shouldGen = shouldGen;
     }
 
     @Override
@@ -212,18 +220,22 @@ public void run() {
      * Requests a batch of chunks to be loaded
      */
     private void requestBatch() {
-        BlockVector2 chunk;
-        for (int i = 0; i < this.batchSize && (chunk = this.requestedChunks.poll()) != null; i++) {
+        for (int i = 0; i < this.batchSize && this.requestedChunks.peek() != null; i++) {
             // This required PaperLib to be bumped to version 1.0.4 to mark the request as urgent
+            final BlockVector2 chunk = this.requestedChunks.poll();
             loadingChunks.incrementAndGet();
             PaperLib
-                    .getChunkAtAsync(this.bukkitWorld, chunk.getX(), chunk.getZ(), true, true)
+                    .getChunkAtAsync(this.bukkitWorld, chunk.getX(), chunk.getZ(), shouldGen, true)
+                    .completeOnTimeout(null, 10L, TimeUnit.SECONDS)
                     .whenComplete((chunkObject, throwable) -> {
                         loadingChunks.decrementAndGet();
                         if (throwable != null) {
-                            throwable.printStackTrace();
+                            LOGGER.error("Failed to load chunk {}", chunk, throwable);
                             // We want one less because this couldn't be processed
                             this.expectedSize.decrementAndGet();
+                        } else if (chunkObject == null) {
+                            LOGGER.warn("Timed out awaiting chunk load {}", chunk);
+                            this.requestedChunks.offer(chunk);
                         } else if (PlotSquared.get().isMainThread(Thread.currentThread())) {
                             this.processChunk(chunkObject);
                         } else {

Bukkit/src/main/java/com/plotsquared/bukkit/queue/BukkitQueueCoordinator.java

@@ -238,6 +238,7 @@ public boolean enqueue() {
                         .unloadAfter(isUnloadAfter())
                         .withProgressSubscribers(getProgressSubscribers())
                         .forceSync(isForceSync())
+                        .shouldGen(isShouldGen())
                         .build();
         return super.enqueue();
     }

Core/src/main/java/com/plotsquared/core/generator/HybridUtils.java

@@ -432,6 +432,7 @@ public void run() {
                 if (!UPDATE) {
                     Iterator<BlockVector2> iter = chunks.iterator();
                     QueueCoordinator queue = blockQueue.getNewQueue(worldUtil.getWeWorld(area.getWorldName()));
+                    queue.setShouldGen(false);
                     while (iter.hasNext()) {
                         BlockVector2 chunk = iter.next();
                         iter.remove();
@@ -474,6 +475,7 @@ public void run() {
                                     Iterator<BlockVector2> iterator = chunks.iterator();
                                     if (chunks.size() >= 32) {
                                         QueueCoordinator queue = blockQueue.getNewQueue(worldUtil.getWeWorld(area.getWorldName()));
+                                        queue.setShouldGen(false);
                                         for (int i = 0; i < 32; i++) {
                                             final BlockVector2 chunk = iterator.next();
                                             iterator.remove();
@@ -487,6 +489,7 @@ public void run() {
                                         return null;
                                     }
                                     QueueCoordinator queue = blockQueue.getNewQueue(worldUtil.getWeWorld(area.getWorldName()));
+                                    queue.setShouldGen(false);
                                     while (!chunks.isEmpty()) {
                                         final BlockVector2 chunk = iterator.next();
                                         iterator.remove();
@@ -502,15 +505,15 @@ public void run() {
                                 return;
                             }
                         } catch (Exception e) {
-                            e.printStackTrace();
                             Iterator<BlockVector2> iterator = HybridUtils.regions.iterator();
                             BlockVector2 loc = iterator.next();
                             iterator.remove();
                             LOGGER.error(
                                     "Error! Could not update '{}/region/r.{}.{}.mca' (Corrupt chunk?)",
                                     area.getWorldHash(),
                                     loc.getX(),
-                                    loc.getZ()
+                                    loc.getZ(),
+                                    e
                             );
                         }
                         TaskManager.runTaskLater(task, TaskTime.seconds(1L));
@@ -558,7 +561,7 @@ public boolean setupRoadSchematic(Plot plot) {
                                 try {
                                     plotworld.setupSchematics();
                                 } catch (SchematicHandler.UnsupportedFormatException e) {
-                                    e.printStackTrace();
+                                    LOGGER.error(e);
                                 }
                             });
                 });

Core/src/main/java/com/plotsquared/core/inject/factory/ChunkCoordinatorFactory.java

@@ -40,7 +40,8 @@ public interface ChunkCoordinatorFactory {
             final @NonNull Consumer<Throwable> throwableConsumer,
             @Assisted("unloadAfter") final boolean unloadAfter,
             final @NonNull Collection<ProgressSubscriber> progressSubscribers,
-            @Assisted("forceSync") final boolean forceSync
+            @Assisted("forceSync") final boolean forceSync,
+            @Assisted("shouldGen") final boolean shouldGen
     );
 
 }

Core/src/main/java/com/plotsquared/core/queue/ChunkCoordinatorBuilder.java

@@ -52,6 +52,7 @@ public class ChunkCoordinatorBuilder {
     private int initialBatchSize = Settings.QUEUE.INITIAL_BATCH_SIZE;
     private boolean unloadAfter = true;
     private boolean forceSync = false;
+    private boolean shouldGen = true;
 
     @Inject
     public ChunkCoordinatorBuilder(@NonNull ChunkCoordinatorFactory chunkCoordinatorFactory) {
@@ -203,6 +204,19 @@ public ChunkCoordinatorBuilder(@NonNull ChunkCoordinatorFactory chunkCoordinator
         return this;
     }
 
+    /**
+     * Set whether chunks should be generated as part of this operation. Default is true. Disabling this may not be supported
+     * depending on server implementation. (i.e. setting to false may not actually disable generation as part of this operation
+     * - this is just a catch-all in case of future differing server implementations; the option will work on Spigot/Paper).
+     *
+     * @param shouldGen should generate new chunks or not
+     * @since TODO
+     */
+    public @NonNull ChunkCoordinatorBuilder shouldGen(final boolean shouldGen) {
+        this.shouldGen = shouldGen;
+        return this;
+    }
+
     public @NonNull ChunkCoordinatorBuilder withProgressSubscriber(ProgressSubscriber progressSubscriber) {
         this.progressSubscribers.add(progressSubscriber);
         return this;
@@ -234,7 +248,8 @@ public ChunkCoordinatorBuilder(@NonNull ChunkCoordinatorFactory chunkCoordinator
                         this.throwableConsumer,
                         this.unloadAfter,
                         this.progressSubscribers,
-                        this.forceSync
+                        this.forceSync,
+                        this.shouldGen
                 );
     }
 

Core/src/main/java/com/plotsquared/core/queue/DelegateQueueCoordinator.java

@@ -51,6 +51,7 @@ public DelegateQueueCoordinator(QueueCoordinator parent) {
 
         if (parent != null) {
             this.setForceSync(parent.isForceSync());
+            this.setShouldGen(parent.isShouldGen());
         }
     }
 

Core/src/main/java/com/plotsquared/core/queue/QueueCoordinator.java

@@ -45,6 +45,7 @@ public abstract class QueueCoordinator {
 
     private final AtomicBoolean enqueued = new AtomicBoolean();
     private boolean forceSync = false;
+    private boolean shouldGen = true;
     @Nullable
     private Object chunkObject;
     @SuppressWarnings({"unused", "FieldCanBeLocal"})
@@ -110,6 +111,30 @@ public void setForceSync(boolean forceSync) {
         this.forceSync = forceSync;
     }
 
+
+    /**
+     * Get whether chunks should be generated as part of this operation. Default is true. Disabling this may not be supported
+     * depending on server implementation. (i.e. setting to false may not actually disable generation as part of this operation
+     * - this is just a catch-all in case of future differing server implementations; the option will work on Spigot/Paper).
+     *
+     * @since TODO
+     */
+    public boolean isShouldGen() {
+        return shouldGen;
+    }
+
+    /**
+     * Set whether chunks should be generated as part of this operation. Default is true. Disabling this may not be supported
+     * depending on server implementation. (i.e. setting to false may not actually disable generation as part of this operation
+     * - this is just a catch-all in case of future differing server implementations; the option will work on Spigot/Paper).
+     *
+     * @param shouldGen should generate new chunks or not
+     * @since TODO
+     */
+    public void setShouldGen(boolean shouldGen) {
+        this.shouldGen = shouldGen;
+    }
+
     /**
      * Get the Chunk Object set to the queue
      *