PaperMC/paper-server/nms-patches/net/minecraft/world/level/entity/PersistentEntitySectionManager.patch

--- a/net/minecraft/world/level/entity/PersistentEntitySectionManager.java
+++ b/net/minecraft/world/level/entity/PersistentEntitySectionManager.java
@@ -32,6 +32,11 @@
 import net.minecraft.world.level.ChunkCoordIntPair;
 import org.slf4j.Logger;
 
+// CraftBukkit start
+import net.minecraft.world.level.chunk.storage.EntityStorage;
+import org.bukkit.craftbukkit.event.CraftEventFactory;
+// CraftBukkit end
+
 public class PersistentEntitySectionManager<T extends EntityAccess> implements AutoCloseable {
 
     static final Logger LOGGER = LogUtils.getLogger();
@@ -55,6 +60,16 @@
         this.entityGetter = new LevelEntityGetterAdapter<>(this.visibleEntityStorage, this.sectionStorage);
     }
 
+    // CraftBukkit start - add method to get all entities in chunk
+    public List<Entity> getEntities(ChunkCoordIntPair chunkCoordIntPair) {
+        return sectionStorage.getExistingSectionsInChunk(chunkCoordIntPair.toLong()).flatMap(EntitySection::getEntities).map(entity -> (Entity) entity).collect(Collectors.toList());
+    }
+
+    public boolean isPending(long pair) {
+        return chunkLoadStatuses.get(pair) == b.PENDING;
+    }
+    // CraftBukkit end
+
     void removeSectionIfEmpty(long i, EntitySection<T> entitysection) {
         if (entitysection.isEmpty()) {
             this.sectionStorage.remove(i);
@@ -196,6 +211,12 @@
     }
 
     private boolean storeChunkSections(long i, Consumer<T> consumer) {
+        // CraftBukkit start - add boolean for event call
+        return storeChunkSections(i, consumer, false);
+    }
+
+    private boolean storeChunkSections(long i, Consumer<T> consumer, boolean callEvent) {
+        // CraftBukkit end
         PersistentEntitySectionManager.b persistententitysectionmanager_b = (PersistentEntitySectionManager.b) this.chunkLoadStatuses.get(i);
 
         if (persistententitysectionmanager_b == PersistentEntitySectionManager.b.PENDING) {
@@ -207,6 +228,7 @@
 
             if (list.isEmpty()) {
                 if (persistententitysectionmanager_b == PersistentEntitySectionManager.b.LOADED) {
+                    if (callEvent) CraftEventFactory.callEntitiesUnloadEvent(((EntityStorage) permanentStorage).level, new ChunkCoordIntPair(i), ImmutableList.of()); // CraftBukkit
                     this.permanentStorage.storeEntities(new ChunkEntities<>(new ChunkCoordIntPair(i), ImmutableList.of()));
                 }
 
@@ -215,6 +237,7 @@
                 this.requestChunkLoad(i);
                 return false;
             } else {
+                if (callEvent) CraftEventFactory.callEntitiesUnloadEvent(((EntityStorage) permanentStorage).level, new ChunkCoordIntPair(i), list.stream().map(entity -> (Entity) entity).collect(Collectors.toList())); // CraftBukkit
                 this.permanentStorage.storeEntities(new ChunkEntities<>(new ChunkCoordIntPair(i), list));
                 list.forEach(consumer);
                 return true;
@@ -238,7 +261,7 @@
     private boolean processChunkUnload(long i) {
         boolean flag = this.storeChunkSections(i, (entityaccess) -> {
             entityaccess.getPassengersAndSelf().forEach(this::unloadEntity);
-        });
+        }, true); // CraftBukkit - add boolean for event call
 
         if (!flag) {
             return false;
@@ -254,19 +277,23 @@
     }
 
     private void processUnloads() {
-        this.chunksToUnload.removeIf((i) -> {
+        this.chunksToUnload.removeIf((java.util.function.LongPredicate) (i) -> { // CraftBukkit - decompile error
             return this.chunkVisibility.get(i) != Visibility.HIDDEN ? true : this.processChunkUnload(i);
         });
     }
 
     private void processPendingLoads() {
-        ChunkEntities chunkentities;
+        ChunkEntities<T> chunkentities; // CraftBukkit - decompile error
 
         while ((chunkentities = (ChunkEntities) this.loadingInbox.poll()) != null) {
             chunkentities.getEntities().forEach((entityaccess) -> {
                 this.addEntity(entityaccess, true);
             });
             this.chunkLoadStatuses.put(chunkentities.getPos().toLong(), PersistentEntitySectionManager.b.LOADED);
+            // CraftBukkit start - call entity load event
+            List<Entity> entities = getEntities(chunkentities.getPos());
+            CraftEventFactory.callEntitiesLoadEvent(((EntityStorage) permanentStorage).level, chunkentities.getPos(), entities);
+            // CraftBukkit end
         }
 
     }
@@ -292,7 +319,7 @@
     }
 
     public void autoSave() {
-        this.getAllChunksToSave().forEach((i) -> {
+        this.getAllChunksToSave().forEach((java.util.function.LongConsumer) (i) -> { // CraftBukkit - decompile error
             boolean flag = this.chunkVisibility.get(i) == Visibility.HIDDEN;
 
             if (flag) {
@@ -311,7 +338,7 @@
         while (!longset.isEmpty()) {
             this.permanentStorage.flush(false);
             this.processPendingLoads();
-            longset.removeIf((i) -> {
+            longset.removeIf((java.util.function.LongPredicate) (i) -> { // CraftBukkit - decompile error
                 boolean flag = this.chunkVisibility.get(i) == Visibility.HIDDEN;
 
                 return flag ? this.processChunkUnload(i) : this.storeChunkSections(i, (entityaccess) -> {
@@ -323,7 +350,15 @@
     }
 
     public void close() throws IOException {
-        this.saveAll();
+        // CraftBukkit start - add save boolean
+        close(true);
+    }
+
+    public void close(boolean save) throws IOException {
+        if (save) {
+            this.saveAll();
+        }
+        // CraftBukkit end
         this.permanentStorage.close();
     }
 
@@ -350,7 +385,7 @@
     public void dumpSections(Writer writer) throws IOException {
         CSVWriter csvwriter = CSVWriter.builder().addColumn("x").addColumn("y").addColumn("z").addColumn("visibility").addColumn("load_status").addColumn("entity_count").build(writer);
 
-        this.sectionStorage.getAllChunksWithExistingSections().forEach((i) -> {
+        this.sectionStorage.getAllChunksWithExistingSections().forEach((java.util.function.LongConsumer) (i) -> { // CraftBukkit - decompile error
             PersistentEntitySectionManager.b persistententitysectionmanager_b = (PersistentEntitySectionManager.b) this.chunkLoadStatuses.get(i);
 
             this.sectionStorage.getExistingSectionPositionsInChunk(i).forEach((j) -> {
@@ -389,7 +424,7 @@
         private EntitySection<T> currentSection;
 
         a(EntityAccess entityaccess, long i, EntitySection entitysection) {
-            this.entity = entityaccess;
+            this.entity = (T) entityaccess; // CraftBukkit - decompile error
             this.currentSectionKey = i;
             this.currentSection = entitysection;
         }