SPIGOT-2439: Consistently fire Chunk(Load|Unload)Event

Clean up implementation and firing of both of these events by routing
both unload and load behaviors to consistent method calls.

This fixes issues where a few places would not call Load or Unload events
when it should have.

Additionally, reduces diff by moving the neighbor marking code into these
consistent points.

Additional benefits of the change include improving the neighbor marking
methods to use getChunkIfLoaded instead of getLoadedChunkAt in some places,
as the latter will cause chunks to be marked active and not unload.

Finally, this also updates CraftWorld.loadChunk to use the new methods, as the
previous logic did not properly handle the new unload queue.

2 files changed, 21 insertions, 89 deletions

diff --git a/src/main/java/org/bukkit/craftbukkit/CraftWorld.java b/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
index 3ee0b91e..2fe3eae8 100644
--- a/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
+++ b/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
@@ -187,47 +187,26 @@ public class CraftWorld implements World {
             return false;
         }
 
-        return unloadChunk0(x, z, save, safe);
+        return unloadChunk0(x, z, save);
     }
 
-    private boolean unloadChunk0(int x, int z, boolean save, boolean safe) {
-        net.minecraft.server.Chunk chunk = world.getChunkProviderServer().getChunkAt(x, z);
-        if (chunk.mustSave) {   // If chunk had previously been queued to save, must do save to avoid loss of that data
-            save = true;
-        }
-
-        chunk.removeEntities(); // Always remove entities - even if discarding, need to get them out of world table
-
-        if (save) {
-            world.getChunkProviderServer().saveChunk(chunk);
-            world.getChunkProviderServer().saveChunkNOP(chunk);
-        }
-
-        world.getChunkProviderServer().unloadQueue.remove(ChunkCoordIntPair.a(x, z));
-        world.getChunkProviderServer().chunks.remove(ChunkCoordIntPair.a(x, z));
-
-        // Update neighbor counts
-        for (int xx = -2; xx < 3; xx++) {
-            for (int zz = -2; zz < 3; zz++) {
-                if (xx == 0 && zz == 0) {
-                    continue;
-                }
-
-                net.minecraft.server.Chunk neighbor = world.getChunkProviderServer().getChunkIfLoaded(chunk.locX + x, chunk.locZ + z);
-                if (neighbor != null) {
-                    neighbor.setNeighborUnloaded(-xx, -zz);
-                    chunk.setNeighborUnloaded(xx, zz);
-                }
-            }
+    private boolean unloadChunk0(int x, int z, boolean save) {
+        net.minecraft.server.Chunk chunk = world.getChunkProviderServer().getChunkIfLoaded(x, z);
+        if (chunk == null) {
+            return true;
         }
 
-        return true;
+        // If chunk had previously been queued to save, must do save to avoid loss of that data
+        return world.getChunkProviderServer().unloadChunk(chunk, chunk.mustSave || save);
     }
 
     public boolean regenerateChunk(int x, int z) {
-        unloadChunk0(x, z, false, false);
+        if (!unloadChunk0(x, z, false)) {
+            return false;
+        }
 
-        world.getChunkProviderServer().unloadQueue.remove(ChunkCoordIntPair.a(x, z));
+        final long chunkKey = ChunkCoordIntPair.a(x, z);
+        world.getChunkProviderServer().unloadQueue.remove(chunkKey);
 
         net.minecraft.server.Chunk chunk = null;
 
@@ -237,9 +216,14 @@ public class CraftWorld implements World {
             playerChunk.chunk = chunk;
         }
 
-        chunkLoadPostProcess(chunk, x, z);
+        if (chunk != null) {
+            world.getChunkProviderServer().chunks.put(chunkKey, chunk);
 
-        refreshChunk(x, z);
+            chunk.addEntities();
+            chunk.loadNearby(world.getChunkProviderServer(), world.getChunkProviderServer().chunkGenerator, true);
+
+            refreshChunk(x, z);
+        }
 
         return chunk != null;
     }
@@ -275,39 +259,7 @@ public class CraftWorld implements World {
             return world.getChunkProviderServer().getChunkAt(x, z) != null;
         }
 
-        world.getChunkProviderServer().unloadQueue.remove(ChunkCoordIntPair.a(x, z));
-        net.minecraft.server.Chunk chunk = world.getChunkProviderServer().chunks.get(ChunkCoordIntPair.a(x, z));
-
-        if (chunk == null) {
-            chunk = world.getChunkProviderServer().getOrLoadChunkAt(x, z);
-        }
-        return chunk != null;
-    }
-
-    private void chunkLoadPostProcess(net.minecraft.server.Chunk chunk, int cx, int cz) {
-        if (chunk != null) {
-            world.getChunkProviderServer().chunks.put(ChunkCoordIntPair.a(cx, cz), chunk);
-
-            chunk.addEntities();
-
-            // Update neighbor counts
-            for (int x = -2; x < 3; x++) {
-                for (int z = -2; z < 3; z++) {
-                    if (x == 0 && z == 0) {
-                        continue;
-                    }
-
-                    net.minecraft.server.Chunk neighbor = world.getChunkProviderServer().getLoadedChunkAt(chunk.locX + x, chunk.locZ + z);
-                    if (neighbor != null) {
-                        neighbor.setNeighborLoaded(-x, -z);
-                        chunk.setNeighborLoaded(x, z);
-                    }
-                }
-            }
-            // CraftBukkit end
-
-            chunk.loadNearby(world.getChunkProviderServer(), world.getChunkProviderServer().chunkGenerator);
-        }
+        return world.getChunkProviderServer().getOrLoadChunkAt(x, z) != null;
     }
 
     public boolean isChunkLoaded(Chunk chunk) {
diff --git a/src/main/java/org/bukkit/craftbukkit/chunkio/ChunkIOProvider.java b/src/main/java/org/bukkit/craftbukkit/chunkio/ChunkIOProvider.java
index 1632f136..f1c1dc49 100644
--- a/src/main/java/org/bukkit/craftbukkit/chunkio/ChunkIOProvider.java
+++ b/src/main/java/org/bukkit/craftbukkit/chunkio/ChunkIOProvider.java
@@ -48,27 +48,7 @@ class ChunkIOProvider implements AsynchronousExecutor.CallBackProvider<QueuedChu
             queuedChunk.provider.chunkGenerator.recreateStructures(chunk, queuedChunk.x, queuedChunk.z);
         }
 
-        Server server = queuedChunk.provider.world.getServer();
-        if (server != null) {
-            server.getPluginManager().callEvent(new org.bukkit.event.world.ChunkLoadEvent(chunk.bukkitChunk, false));
-        }
-
-        // Update neighbor counts
-        for (int x = -2; x < 3; x++) {
-            for (int z = -2; z < 3; z++) {
-                if (x == 0 && z == 0) {
-                    continue;
-                }
-
-                Chunk neighbor = queuedChunk.provider.getLoadedChunkAt(chunk.locX + x, chunk.locZ + z);
-                if (neighbor != null) {
-                    neighbor.setNeighborLoaded(-x, -z);
-                    chunk.setNeighborLoaded(x, z);
-                }
-            }
-        }
-
-        chunk.loadNearby(queuedChunk.provider, queuedChunk.provider.chunkGenerator);
+        chunk.loadNearby(queuedChunk.provider, queuedChunk.provider.chunkGenerator, false);
     }
 
     public void callStage3(QueuedChunk queuedChunk, Chunk chunk, Runnable runnable) throws RuntimeException {