Chunk Zstd compression

build.gradle

@@ -16,5 +16,6 @@ dependencies {
     testCompile group: 'junit', name: 'junit', version: '4.12'
     implementation 'com.github.Adamaq01:ozao-net:2.3.1'
     compile 'com.github.Querz:NBT:4.1'
+    // https://mvnrepository.com/artifact/org.lz4/lz4-java
     implementation 'com.github.luben:zstd-jni:1.4.3-1'
 }

src/main/java/fr/themode/minestom/entity/Entity.java

@@ -310,7 +310,8 @@ public abstract class Entity implements Viewable, DataContainer {
         synchronized (entityById) {
             entityById.remove(id);
         }
-        instance.removeEntity(this);
+        if (instance != null)
+            instance.removeEntity(this);
     }
 
     public void scheduleRemove(long delay) {

src/main/java/fr/themode/minestom/entity/Player.java

@@ -142,6 +142,7 @@ public class Player extends LivingEntity {
 
         setEventCallback(PlayerSpawnPacket.class, event -> {
             System.out.println("TELEPORT");
+            setGameMode(GameMode.CREATIVE);
             teleport(new Position(0, 66, 0));
             for (int cx = 0; cx < 4; cx++)
                 for (int cz = 0; cz < 4; cz++) {

src/main/java/fr/themode/minestom/instance/ChunkLoaderIO.java

@@ -1,5 +1,6 @@
 package fr.themode.minestom.instance;
 
+import com.github.luben.zstd.Zstd;
 import fr.themode.minestom.Main;
 import fr.themode.minestom.utils.SerializerUtils;
 
@@ -9,9 +10,10 @@ import java.util.concurrent.ExecutorService;
 import java.util.concurrent.Executors;
 import java.util.function.Consumer;
 
-// TODO compression
 public class ChunkLoaderIO {
 
+    private static final int COMPRESSION_LEVEL = 1;
+
     private ExecutorService chunkLoaderPool = Executors.newFixedThreadPool(Main.THREAD_COUNT_CHUNK_IO);
 
     private static File getChunkFile(int chunkX, int chunkZ, File folder) {
@@ -27,8 +29,14 @@ public class ChunkLoaderIO {
             File chunkFile = getChunkFile(chunk.getChunkX(), chunk.getChunkZ(), folder);
             try (FileOutputStream fos = new FileOutputStream(chunkFile)) {
                 byte[] data = chunk.getSerializedData();
-                // Zstd.compress(data, 1)
-                fos.write(data);
+                byte[] decompressedLength = SerializerUtils.intToBytes(data.length);
+                byte[] compressed = Zstd.compress(data, COMPRESSION_LEVEL);
+
+                byte[] result = new byte[decompressedLength.length + compressed.length];
+                System.arraycopy(decompressedLength, 0, result, 0, decompressedLength.length);
+                System.arraycopy(compressed, 0, result, decompressedLength.length, compressed.length);
+
+                fos.write(result);
             } catch (FileNotFoundException e) {
                 e.printStackTrace();
             } catch (IOException e) {
@@ -48,12 +56,27 @@ public class ChunkLoaderIO {
                 return;
             }
 
-            byte[] array = new byte[0];
+            byte[] array;
             try {
                 array = Files.readAllBytes(getChunkFile(chunkX, chunkZ, instance.getFolder()).toPath());
             } catch (IOException e) {
                 e.printStackTrace();
+                instance.createChunk(chunkX, chunkZ, callback); // Unknown error, create new chunk by default
+                return;
             }
+
+            int decompressedLength = SerializerUtils.bytesToInt(array);
+
+            byte[] compressedChunkData = new byte[array.length - 4];
+            System.arraycopy(array, 4, compressedChunkData, 0, compressedChunkData.length); // Remove the decompressed length from the array
+
+            byte[] decompressed = new byte[decompressedLength];
+            long result = Zstd.decompress(decompressed, compressedChunkData); // Decompressed in an array with the max size
+
+            array = new byte[(int) result];
+            System.arraycopy(decompressed, 0, array, 0, (int) result); // Resize the data array properly
+
+
             DataInputStream stream = new DataInputStream(new ByteArrayInputStream(array));
 
             Chunk chunk = null;
@@ -65,6 +88,7 @@ public class ChunkLoaderIO {
                     int index = stream.readInt();
                     boolean isCustomBlock = stream.readBoolean();
                     short blockId = stream.readShort();
+                    //System.out.println("id: " + blockId);
 
                     byte[] chunkPos = SerializerUtils.indexToChunkPosition(index);
                     if (isCustomBlock) {
@@ -77,6 +101,7 @@ public class ChunkLoaderIO {
             } catch (IOException e) {
                 e.printStackTrace();
             }
+
             callback.accept(chunk); // Success, null if file isn't properly encoded
         });
     }

src/main/java/fr/themode/minestom/net/packet/client/login/LoginStartPacket.java

@@ -112,7 +112,6 @@ public class LoginStartPacket implements ClientPreplayPacket {
 
         // Next is optional TODO put all that somewhere else (LoginEvent)
         // TODO LoginEvent in another thread (here we are in netty thread)
-        System.out.println("ADD WAITING PLAYER");
         Main.getEntityManager().addWaitingPlayer(player);