rewrite linear region

divinemc-server/build.gradle.kts.patch

@@ -48,7 +48,7 @@
      }
  }
  
-@@ -142,10 +_,22 @@
+@@ -142,10 +_,23 @@
  }
  
  dependencies {
@@ -62,6 +62,7 @@
 +    }
 +    implementation("net.objecthunter:exp4j:0.4.8")
 +    implementation("org.agrona:agrona:2.0.1")
++    implementation("net.openhft:zero-allocation-hashing:0.16")
 +    implementation("com.github.luben:zstd-jni:1.5.6-9")
 +    implementation("org.lz4:lz4-java:1.8.0")
 +    // DivineMC end

divinemc-server/minecraft-patches/features/0003-Completely-remove-Mojang-profiler.patch

@@ -1293,7 +1293,7 @@ index 6540b2d6a1062d883811ce240c49d30d1925b291..8055b8552b40160732953b15876dda79
          }
  
 diff --git a/net/minecraft/server/level/ServerLevel.java b/net/minecraft/server/level/ServerLevel.java
-index 3c3e8e58cd2761ab2f0652e63f944a5c9a95dca8..3980e0dfb08a357384ea33670fb282a26a598f6e 100644
+index eb6286d34a68bf6eb57877a9cfc2be09615c7e83..f4b1f45f1dc86bd077860f088cdd6da78ecc6020 100644
 --- a/net/minecraft/server/level/ServerLevel.java
 +++ b/net/minecraft/server/level/ServerLevel.java
 @@ -77,8 +77,6 @@ import net.minecraft.util.ProgressListener;
@@ -1437,7 +1437,7 @@ index 3c3e8e58cd2761ab2f0652e63f944a5c9a95dca8..3980e0dfb08a357384ea33670fb282a2
      }
  
      @VisibleForTesting
-@@ -1330,17 +1296,13 @@ public class ServerLevel extends Level implements ServerEntityGetter, WorldGenLe
+@@ -1356,17 +1322,13 @@ public class ServerLevel extends Level implements ServerEntityGetter, WorldGenLe
              }
              // Paper end - log detailed entity tick information
          entity.setOldPosAndRot();
@@ -1455,7 +1455,7 @@ index 3c3e8e58cd2761ab2f0652e63f944a5c9a95dca8..3980e0dfb08a357384ea33670fb282a2
  
          for (Entity entity1 : entity.getPassengers()) {
              this.tickPassenger(entity, entity1, isActive); // Paper - EAR 2
-@@ -1361,9 +1323,6 @@ public class ServerLevel extends Level implements ServerEntityGetter, WorldGenLe
+@@ -1387,9 +1349,6 @@ public class ServerLevel extends Level implements ServerEntityGetter, WorldGenLe
              passengerEntity.setOldPosAndRot();
              passengerEntity.tickCount++;
              passengerEntity.totalEntityAge++; // Paper - age-like counter for all entities
@@ -1465,7 +1465,7 @@ index 3c3e8e58cd2761ab2f0652e63f944a5c9a95dca8..3980e0dfb08a357384ea33670fb282a2
              // Paper start - EAR 2
              if (isActive) {
              passengerEntity.rideTick();
-@@ -1375,7 +1334,6 @@ public class ServerLevel extends Level implements ServerEntityGetter, WorldGenLe
+@@ -1401,7 +1360,6 @@ public class ServerLevel extends Level implements ServerEntityGetter, WorldGenLe
                  ridingEntity.positionRider(passengerEntity);
              }
              // Paper end - EAR 2

divinemc-server/minecraft-patches/features/0006-Multithreaded-Tracker.patch

@@ -208,10 +208,10 @@ index 0fb253aa55a24b56b17f524b3261c5b75c7d7e59..b6053158f5d9b6ad325ea075ab7c60f9
  
              attributesToSync.clear();
 diff --git a/net/minecraft/server/level/ServerLevel.java b/net/minecraft/server/level/ServerLevel.java
-index 9afd448ede87c9192dc576f66e08676a68b34d98..d4b44e0fdf113e66c45cc86221df20fe2d3bb9f0 100644
+index c229d69ce3d007e4cb57e559611b3fca7a03562f..ba5ca5213fafd60b2257409f334a7c6b28fe918a 100644
 --- a/net/minecraft/server/level/ServerLevel.java
 +++ b/net/minecraft/server/level/ServerLevel.java
-@@ -2471,7 +2471,7 @@ public class ServerLevel extends Level implements ServerEntityGetter, WorldGenLe
+@@ -2497,7 +2497,7 @@ public class ServerLevel extends Level implements ServerEntityGetter, WorldGenLe
  
      @Override
      public LevelEntityGetter<Entity> getEntities() {
@@ -220,7 +220,7 @@ index 9afd448ede87c9192dc576f66e08676a68b34d98..d4b44e0fdf113e66c45cc86221df20fe
          return this.moonrise$getEntityLookup(); // Paper - rewrite chunk system
      }
  
-@@ -2698,7 +2698,7 @@ public class ServerLevel extends Level implements ServerEntityGetter, WorldGenLe
+@@ -2724,7 +2724,7 @@ public class ServerLevel extends Level implements ServerEntityGetter, WorldGenLe
                          }
  
                          map.carriedByPlayers.remove(player);

divinemc-server/minecraft-patches/features/0008-Parallel-world-ticking.patch

@@ -435,7 +435,7 @@ index 0d889730641fd88d4da0c9116226a4dae385e846..f7a061ad623fa909389c60c1d5b4be84
          try {
              org.purpurmc.purpur.PurpurConfig.init((java.io.File) options.valueOf("purpur-settings"));
 diff --git a/net/minecraft/server/level/ServerLevel.java b/net/minecraft/server/level/ServerLevel.java
-index d4b44e0fdf113e66c45cc86221df20fe2d3bb9f0..50ea7f4a0428cbc49fb13a31b1fa643e00ef9434 100644
+index ba5ca5213fafd60b2257409f334a7c6b28fe918a..52ba052fc1ff2a35786570c282a7de4e9dff99f5 100644
 --- a/net/minecraft/server/level/ServerLevel.java
 +++ b/net/minecraft/server/level/ServerLevel.java
 @@ -182,7 +182,7 @@ public class ServerLevel extends Level implements ServerEntityGetter, WorldGenLe
@@ -463,7 +463,7 @@ index d4b44e0fdf113e66c45cc86221df20fe2d3bb9f0..50ea7f4a0428cbc49fb13a31b1fa643e
          this.preciseTime = this.serverLevelData.getDayTime(); // Purpur - Configurable daylight cycle
      }
  
-@@ -1255,12 +1257,12 @@ public class ServerLevel extends Level implements ServerEntityGetter, WorldGenLe
+@@ -1281,12 +1283,12 @@ public class ServerLevel extends Level implements ServerEntityGetter, WorldGenLe
          if (fluidState.is(fluid)) {
              fluidState.tick(this, pos, blockState);
          }
@@ -481,7 +481,7 @@ index d4b44e0fdf113e66c45cc86221df20fe2d3bb9f0..50ea7f4a0428cbc49fb13a31b1fa643e
      }
  
      private void tickBlock(BlockPos pos, Block block) {
-@@ -1268,12 +1270,12 @@ public class ServerLevel extends Level implements ServerEntityGetter, WorldGenLe
+@@ -1294,12 +1296,12 @@ public class ServerLevel extends Level implements ServerEntityGetter, WorldGenLe
          if (blockState.is(block)) {
              blockState.tick(this, pos, this.random);
          }
@@ -499,7 +499,7 @@ index d4b44e0fdf113e66c45cc86221df20fe2d3bb9f0..50ea7f4a0428cbc49fb13a31b1fa643e
      }
  
      // Paper start - log detailed entity tick information
-@@ -1522,6 +1524,7 @@ public class ServerLevel extends Level implements ServerEntityGetter, WorldGenLe
+@@ -1548,6 +1550,7 @@ public class ServerLevel extends Level implements ServerEntityGetter, WorldGenLe
      }
  
      private void addPlayer(ServerPlayer player) {
@@ -507,7 +507,7 @@ index d4b44e0fdf113e66c45cc86221df20fe2d3bb9f0..50ea7f4a0428cbc49fb13a31b1fa643e
          Entity entity = this.getEntities().get(player.getUUID());
          if (entity != null) {
              LOGGER.warn("Force-added player with duplicate UUID {}", player.getUUID());
-@@ -1534,7 +1537,13 @@ public class ServerLevel extends Level implements ServerEntityGetter, WorldGenLe
+@@ -1560,7 +1563,13 @@ public class ServerLevel extends Level implements ServerEntityGetter, WorldGenLe
  
      // CraftBukkit start
      private boolean addEntity(Entity entity, org.bukkit.event.entity.CreatureSpawnEvent.SpawnReason spawnReason) {

divinemc-server/minecraft-patches/features/0010-Chunk-System-Optimizations.patch

@@ -1092,7 +1092,7 @@ index ab30af9cd58ff7310e05be87b08f42bacf69e11e..ae0e36d198ad8243920c8e8a55c0be49
      }
  
 diff --git a/net/minecraft/server/level/ServerLevel.java b/net/minecraft/server/level/ServerLevel.java
-index 50ea7f4a0428cbc49fb13a31b1fa643e00ef9434..a70007d324e2169d1b2a1a11046500196b8b5660 100644
+index 52ba052fc1ff2a35786570c282a7de4e9dff99f5..9298bdca9a653622f3625190e875e7b6c5e40023 100644
 --- a/net/minecraft/server/level/ServerLevel.java
 +++ b/net/minecraft/server/level/ServerLevel.java
 @@ -181,6 +181,7 @@ public class ServerLevel extends Level implements ServerEntityGetter, WorldGenLe
@@ -1199,7 +1199,7 @@ index 50ea7f4a0428cbc49fb13a31b1fa643e00ef9434..a70007d324e2169d1b2a1a1104650019
      }
      // Paper end - optimise random ticking
  
-@@ -2531,30 +2533,25 @@ public class ServerLevel extends Level implements ServerEntityGetter, WorldGenLe
+@@ -2557,30 +2559,25 @@ public class ServerLevel extends Level implements ServerEntityGetter, WorldGenLe
  
      private boolean isPositionTickingWithEntitiesLoaded(long chunkPos) {
          // Paper start - rewrite chunk system

divinemc-server/minecraft-patches/features/0039-Linear-region-file-format.patch

@@ -5,7 +5,7 @@ Subject: [PATCH] Linear region file format
 
 
 diff --git a/ca/spottedleaf/moonrise/patches/chunk_system/io/ChunkSystemRegionFileStorage.java b/ca/spottedleaf/moonrise/patches/chunk_system/io/ChunkSystemRegionFileStorage.java
-index a814512fcfb85312474ae2c2c21443843bf57831..c21e04c1d43797db221e4712fcc987a44eaa983c 100644
+index a814512fcfb85312474ae2c2c21443843bf57831..fdccc27c528b01b16a72e614ffd96523aa6f50d2 100644
 --- a/ca/spottedleaf/moonrise/patches/chunk_system/io/ChunkSystemRegionFileStorage.java
 +++ b/ca/spottedleaf/moonrise/patches/chunk_system/io/ChunkSystemRegionFileStorage.java
 @@ -8,9 +8,9 @@ public interface ChunkSystemRegionFileStorage {
@@ -13,15 +13,15 @@ index a814512fcfb85312474ae2c2c21443843bf57831..c21e04c1d43797db221e4712fcc987a4
      public boolean moonrise$doesRegionFileNotExistNoIO(final int chunkX, final int chunkZ);
  
 -    public RegionFile moonrise$getRegionFileIfLoaded(final int chunkX, final int chunkZ);
-+    public org.stupidcraft.linearpaper.region.IRegionFile moonrise$getRegionFileIfLoaded(final int chunkX, final int chunkZ); // DivineMC - Linear region file format
++    public org.bxteam.divinemc.region.IRegionFile moonrise$getRegionFileIfLoaded(final int chunkX, final int chunkZ); // DivineMC - Linear region file format
  
 -    public RegionFile moonrise$getRegionFileIfExists(final int chunkX, final int chunkZ) throws IOException;
-+    public org.stupidcraft.linearpaper.region.IRegionFile moonrise$getRegionFileIfExists(final int chunkX, final int chunkZ) throws IOException; // DivineMC - Linear region file format
++    public org.bxteam.divinemc.region.IRegionFile moonrise$getRegionFileIfExists(final int chunkX, final int chunkZ) throws IOException; // DivineMC - Linear region file format
  
      public MoonriseRegionFileIO.RegionDataController.WriteData moonrise$startWrite(
              final int chunkX, final int chunkZ, final CompoundTag compound
 diff --git a/ca/spottedleaf/moonrise/patches/chunk_system/io/MoonriseRegionFileIO.java b/ca/spottedleaf/moonrise/patches/chunk_system/io/MoonriseRegionFileIO.java
-index 98fbc5c8044bd945d64569f13412a6e7e49a4e7f..57ae23fdd5a95e7670eb4dfaca0d290edfc1d25c 100644
+index 98fbc5c8044bd945d64569f13412a6e7e49a4e7f..34682217252cb98a70511a8cb25f077ec9f872b8 100644
 --- a/ca/spottedleaf/moonrise/patches/chunk_system/io/MoonriseRegionFileIO.java
 +++ b/ca/spottedleaf/moonrise/patches/chunk_system/io/MoonriseRegionFileIO.java
 @@ -1260,7 +1260,7 @@ public final class MoonriseRegionFileIO {
@@ -29,7 +29,7 @@ index 98fbc5c8044bd945d64569f13412a6e7e49a4e7f..57ae23fdd5a95e7670eb4dfaca0d290e
                  // Paper start - flush regionfiles on save
                  if (this.world.paperConfig().chunks.flushRegionsOnSave) {
 -                    final RegionFile regionFile = this.regionDataController.getCache().moonrise$getRegionFileIfLoaded(this.chunkX, this.chunkZ);
-+                    final org.stupidcraft.linearpaper.region.IRegionFile regionFile = this.regionDataController.getCache().moonrise$getRegionFileIfLoaded(this.chunkX, this.chunkZ); // DivineMC - Linear region file format
++                    final org.bxteam.divinemc.region.IRegionFile regionFile = this.regionDataController.getCache().moonrise$getRegionFileIfLoaded(this.chunkX, this.chunkZ); // DivineMC - Linear region file format
                      if (regionFile != null) {
                          regionFile.flush();
                      } // else: evicted from cache, which should have called flush
@@ -38,12 +38,12 @@ index 98fbc5c8044bd945d64569f13412a6e7e49a4e7f..57ae23fdd5a95e7670eb4dfaca0d290e
          public static interface IORunnable {
  
 -            public void run(final RegionFile regionFile) throws IOException;
-+            public void run(final org.stupidcraft.linearpaper.region.IRegionFile regionFile) throws IOException; // DivineMC - Linear region file format
++            public void run(final org.bxteam.divinemc.region.IRegionFile regionFile) throws IOException; // DivineMC - Linear region file format
  
          }
      }
 diff --git a/ca/spottedleaf/moonrise/patches/chunk_system/storage/ChunkSystemChunkBuffer.java b/ca/spottedleaf/moonrise/patches/chunk_system/storage/ChunkSystemChunkBuffer.java
-index 51c126735ace8fdde89ad97b5cab62f244212db0..c466ce5c669e4b5ed835b13584a5ae5afe08fa11 100644
+index 51c126735ace8fdde89ad97b5cab62f244212db0..8713d00d767c9225a0823d2fdbb0b479005738d7 100644
 --- a/ca/spottedleaf/moonrise/patches/chunk_system/storage/ChunkSystemChunkBuffer.java
 +++ b/ca/spottedleaf/moonrise/patches/chunk_system/storage/ChunkSystemChunkBuffer.java
 @@ -8,5 +8,5 @@ public interface ChunkSystemChunkBuffer {
@@ -51,10 +51,10 @@ index 51c126735ace8fdde89ad97b5cab62f244212db0..c466ce5c669e4b5ed835b13584a5ae5a
      public void moonrise$setWriteOnClose(final boolean value);
  
 -    public void moonrise$write(final RegionFile regionFile) throws IOException;
-+    public void moonrise$write(final org.stupidcraft.linearpaper.region.IRegionFile regionFile) throws IOException; // DivineMC - Linear region file format
++    public void moonrise$write(final org.bxteam.divinemc.region.IRegionFile regionFile) throws IOException; // DivineMC - Linear region file format
  }
 diff --git a/net/minecraft/server/MinecraftServer.java b/net/minecraft/server/MinecraftServer.java
-index 9d6fa3bced0ba5ab3443bdf4ce306598a8e4a31f..34bc5d54de26608e64170bd902baa87da137dab6 100644
+index 26a4a279122bb03a83dd4a34e780d6a4567ba3a8..51b79f614417f231951e9ba05b29ff0044e081e7 100644
 --- a/net/minecraft/server/MinecraftServer.java
 +++ b/net/minecraft/server/MinecraftServer.java
 @@ -947,10 +947,10 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
@@ -71,7 +71,7 @@ index 9d6fa3bced0ba5ab3443bdf4ce306598a8e4a31f..34bc5d54de26608e64170bd902baa87d
  
          return flag;
 diff --git a/net/minecraft/util/worldupdate/WorldUpgrader.java b/net/minecraft/util/worldupdate/WorldUpgrader.java
-index e0bcda2ddea0d6633445a7440fbf0d18e50a7653..2ab8e8d9db5ea390a1334c28b97ef6d05ce3afb3 100644
+index e0bcda2ddea0d6633445a7440fbf0d18e50a7653..e99f3c3567f9e6fb5a328bf9b59d40c72522f922 100644
 --- a/net/minecraft/util/worldupdate/WorldUpgrader.java
 +++ b/net/minecraft/util/worldupdate/WorldUpgrader.java
 @@ -72,7 +72,7 @@ public class WorldUpgrader implements AutoCloseable {
@@ -97,7 +97,7 @@ index e0bcda2ddea0d6633445a7440fbf0d18e50a7653..2ab8e8d9db5ea390a1334c28b97ef6d0
                          List<ChunkPos> list1 = Lists.newArrayList();
  
 -                        try (RegionFile regionFile = new RegionFile(regionStorageInfo, file.toPath(), path, true)) {
-+                        try (org.stupidcraft.linearpaper.region.IRegionFile regionFile = org.stupidcraft.linearpaper.region.IRegionFileFactory.getAbstractRegionFile(regionStorageInfo, file.toPath(), path, true)) { // DivineMC - Linear region file format
++                        try (org.bxteam.divinemc.region.IRegionFile regionFile = org.bxteam.divinemc.region.RegionFileFactory.getAbstractRegionFile(regionStorageInfo, file.toPath(), path, true)) { // DivineMC - Linear region file format
                              for (int i2 = 0; i2 < 32; i2++) {
                                  for (int i3 = 0; i3 < 32; i3++) {
                                      ChunkPos chunkPos = new ChunkPos(i2 + i, i3 + i1);
@@ -106,7 +106,7 @@ index e0bcda2ddea0d6633445a7440fbf0d18e50a7653..2ab8e8d9db5ea390a1334c28b97ef6d0
          protected abstract boolean tryProcessOnePosition(T chunkStorage, ChunkPos chunkPos, ResourceKey<Level> dimension);
  
 -        private void onFileFinished(RegionFile regionFile) {
-+        private void onFileFinished(org.stupidcraft.linearpaper.region.IRegionFile regionFile) { // DivineMC - Linear region file format
++        private void onFileFinished(org.bxteam.divinemc.region.IRegionFile regionFile) { // DivineMC - Linear region file format
              if (WorldUpgrader.this.recreateRegionFiles) {
                  if (this.previousWriteFuture != null) {
                      this.previousWriteFuture.join();
@@ -115,12 +115,12 @@ index e0bcda2ddea0d6633445a7440fbf0d18e50a7653..2ab8e8d9db5ea390a1334c28b97ef6d0
      }
  
 -    record FileToUpgrade(RegionFile file, List<ChunkPos> chunksToUpgrade) {
-+    record FileToUpgrade(org.stupidcraft.linearpaper.region.IRegionFile file, List<ChunkPos> chunksToUpgrade) { // DivineMC - Linear region file format
++    record FileToUpgrade(org.bxteam.divinemc.region.IRegionFile file, List<ChunkPos> chunksToUpgrade) { // DivineMC - Linear region file format
      }
  
      class PoiUpgrader extends WorldUpgrader.SimpleRegionStorageUpgrader {
 diff --git a/net/minecraft/world/level/chunk/storage/RegionFile.java b/net/minecraft/world/level/chunk/storage/RegionFile.java
-index c72494e757a9dc50e053dbc873f7b30e83d5cb8c..5d29e3046485dcdda9356f6bfe6f6463e9b9bef4 100644
+index c72494e757a9dc50e053dbc873f7b30e83d5cb8c..2988084cf2d72557dd304dcb904d09441e79863d 100644
 --- a/net/minecraft/world/level/chunk/storage/RegionFile.java
 +++ b/net/minecraft/world/level/chunk/storage/RegionFile.java
 @@ -22,7 +22,7 @@ import net.minecraft.util.profiling.jfr.JvmProfiler;
@@ -128,7 +128,7 @@ index c72494e757a9dc50e053dbc873f7b30e83d5cb8c..5d29e3046485dcdda9356f6bfe6f6463
  import org.slf4j.Logger;
  
 -public class RegionFile implements AutoCloseable, ca.spottedleaf.moonrise.patches.chunk_system.storage.ChunkSystemRegionFile { // Paper - rewrite chunk system
-+public class RegionFile implements AutoCloseable, ca.spottedleaf.moonrise.patches.chunk_system.storage.ChunkSystemRegionFile, org.stupidcraft.linearpaper.region.IRegionFile { // Paper - rewrite chunk system // DivineMC - Linear region file format
++public class RegionFile implements AutoCloseable, ca.spottedleaf.moonrise.patches.chunk_system.storage.ChunkSystemRegionFile, org.bxteam.divinemc.region.IRegionFile { // Paper - rewrite chunk system // DivineMC - Linear region file format
      private static final Logger LOGGER = LogUtils.getLogger();
      public static final int MAX_CHUNK_SIZE = 500 * 1024 * 1024; // Paper - don't write garbage data to disk if writing serialization fails
      private static final int SECTOR_BYTES = 4096;
@@ -137,12 +137,12 @@ index c72494e757a9dc50e053dbc873f7b30e83d5cb8c..5d29e3046485dcdda9356f6bfe6f6463
  
          @Override
 -        public final void moonrise$write(final RegionFile regionFile) throws IOException {
-+        public final void moonrise$write(final org.stupidcraft.linearpaper.region.IRegionFile regionFile) throws IOException { // DivineMC - Linear region file format
++        public final void moonrise$write(final org.bxteam.divinemc.region.IRegionFile regionFile) throws IOException { // DivineMC - Linear region file format
              regionFile.write(this.pos, ByteBuffer.wrap(this.buf, 0, this.count));
          }
          // Paper end - rewrite chunk system
 diff --git a/net/minecraft/world/level/chunk/storage/RegionFileStorage.java b/net/minecraft/world/level/chunk/storage/RegionFileStorage.java
-index 16cd10ab8de69ca3d29c84cf93715645322fd72a..1061d1480af0d4947d0f7f1b0028b4196cf25588 100644
+index 16cd10ab8de69ca3d29c84cf93715645322fd72a..9fd987078625bee796b381108ae7dbfb1f14d256 100644
 --- a/net/minecraft/world/level/chunk/storage/RegionFileStorage.java
 +++ b/net/minecraft/world/level/chunk/storage/RegionFileStorage.java
 @@ -18,7 +18,7 @@ public class RegionFileStorage implements AutoCloseable, ca.spottedleaf.moonrise
@@ -150,7 +150,7 @@ index 16cd10ab8de69ca3d29c84cf93715645322fd72a..1061d1480af0d4947d0f7f1b0028b419
      public static final String ANVIL_EXTENSION = ".mca";
      private static final int MAX_CACHE_SIZE = 256;
 -    public final Long2ObjectLinkedOpenHashMap<RegionFile> regionCache = new Long2ObjectLinkedOpenHashMap<>();
-+    public final Long2ObjectLinkedOpenHashMap<org.stupidcraft.linearpaper.region.IRegionFile> regionCache = new Long2ObjectLinkedOpenHashMap<>(); // DivineMC - Linear region file format
++    public final Long2ObjectLinkedOpenHashMap<org.bxteam.divinemc.region.IRegionFile> regionCache = new Long2ObjectLinkedOpenHashMap<>(); // DivineMC - Linear region file format
      private final RegionStorageInfo info;
      private final Path folder;
      private final boolean sync;
@@ -168,7 +168,7 @@ index 16cd10ab8de69ca3d29c84cf93715645322fd72a..1061d1480af0d4947d0f7f1b0028b419
      private final it.unimi.dsi.fastutil.longs.LongLinkedOpenHashSet nonExistingRegionFiles = new it.unimi.dsi.fastutil.longs.LongLinkedOpenHashSet();
      private static String getRegionFileName(final int chunkX, final int chunkZ) {
 +        // DivineMC start - Linear region file format
-+        if (org.bxteam.divinemc.DivineConfig.regionFormatTypeName == org.stupidcraft.linearpaper.region.EnumRegionFileExtension.LINEAR) {
++        if (org.bxteam.divinemc.DivineConfig.regionFormatTypeName == org.bxteam.divinemc.region.RegionFileFormat.LINEAR) {
 +            return "r." + (chunkX >> REGION_SHIFT) + "." + (chunkZ >> REGION_SHIFT) + ".linear";
 +        }
 +        // DivineMC end - Linear region file format
@@ -181,17 +181,17 @@ index 16cd10ab8de69ca3d29c84cf93715645322fd72a..1061d1480af0d4947d0f7f1b0028b419
  
      @Override
 -    public synchronized final RegionFile moonrise$getRegionFileIfLoaded(final int chunkX, final int chunkZ) {
-+    public synchronized final org.stupidcraft.linearpaper.region.IRegionFile moonrise$getRegionFileIfLoaded(final int chunkX, final int chunkZ) { // DivineMC - Linear region file format
++    public synchronized final org.bxteam.divinemc.region.IRegionFile moonrise$getRegionFileIfLoaded(final int chunkX, final int chunkZ) { // DivineMC - Linear region file format
          return this.regionCache.getAndMoveToFirst(ChunkPos.asLong(chunkX >> REGION_SHIFT, chunkZ >> REGION_SHIFT));
      }
  
      @Override
 -    public synchronized final RegionFile moonrise$getRegionFileIfExists(final int chunkX, final int chunkZ) throws IOException {
-+    public synchronized final org.stupidcraft.linearpaper.region.IRegionFile moonrise$getRegionFileIfExists(final int chunkX, final int chunkZ) throws IOException { // DivineMC - Linear region file format
++    public synchronized final org.bxteam.divinemc.region.IRegionFile moonrise$getRegionFileIfExists(final int chunkX, final int chunkZ) throws IOException { // DivineMC - Linear region file format
          final long key = ChunkPos.asLong(chunkX >> REGION_SHIFT, chunkZ >> REGION_SHIFT);
  
 -        RegionFile ret = this.regionCache.getAndMoveToFirst(key);
-+        org.stupidcraft.linearpaper.region.IRegionFile ret = this.regionCache.getAndMoveToFirst(key); // DivineMC - Linear region file format
++        org.bxteam.divinemc.region.IRegionFile ret = this.regionCache.getAndMoveToFirst(key); // DivineMC - Linear region file format
          if (ret != null) {
              return ret;
          }
@@ -200,7 +200,7 @@ index 16cd10ab8de69ca3d29c84cf93715645322fd72a..1061d1480af0d4947d0f7f1b0028b419
          FileUtil.createDirectoriesSafe(this.folder);
  
 -        ret = new RegionFile(this.info, regionPath, this.folder, this.sync);
-+        ret = org.stupidcraft.linearpaper.region.IRegionFileFactory.getAbstractRegionFile(this.info, regionPath, this.folder, this.sync); // DivineMC - Linear region file format
++        ret = org.bxteam.divinemc.region.RegionFileFactory.getAbstractRegionFile(this.info, regionPath, this.folder, this.sync); // DivineMC - Linear region file format
  
          this.regionCache.putAndMoveToFirst(key, ret);
  
@@ -209,7 +209,7 @@ index 16cd10ab8de69ca3d29c84cf93715645322fd72a..1061d1480af0d4947d0f7f1b0028b419
  
          final ChunkPos pos = new ChunkPos(chunkX, chunkZ);
 -        final RegionFile regionFile = this.getRegionFile(pos);
-+        final org.stupidcraft.linearpaper.region.IRegionFile regionFile = this.getRegionFile(pos); // DivineMC - Linear region file format
++        final org.bxteam.divinemc.region.IRegionFile regionFile = this.getRegionFile(pos); // DivineMC - Linear region file format
  
          // note: not required to keep regionfile loaded after this call, as the write param takes a regionfile as input
          // (and, the regionfile parameter is unused for writing until the write call)
@@ -223,7 +223,7 @@ index 16cd10ab8de69ca3d29c84cf93715645322fd72a..1061d1480af0d4947d0f7f1b0028b419
          final ChunkPos pos = new ChunkPos(chunkX, chunkZ);
          if (writeData.result() == ca.spottedleaf.moonrise.patches.chunk_system.io.MoonriseRegionFileIO.RegionDataController.WriteData.WriteResult.DELETE) {
 -            final RegionFile regionFile = this.moonrise$getRegionFileIfExists(chunkX, chunkZ);
-+            final org.stupidcraft.linearpaper.region.IRegionFile regionFile = this.moonrise$getRegionFileIfExists(chunkX, chunkZ); // DivineMC - Linear region file format
++            final org.bxteam.divinemc.region.IRegionFile regionFile = this.moonrise$getRegionFileIfExists(chunkX, chunkZ); // DivineMC - Linear region file format
              if (regionFile != null) {
                  regionFile.clear(pos);
              } // else: didn't exist
@@ -232,7 +232,7 @@ index 16cd10ab8de69ca3d29c84cf93715645322fd72a..1061d1480af0d4947d0f7f1b0028b419
          final int chunkX, final int chunkZ
      ) throws IOException {
 -        final RegionFile regionFile = this.moonrise$getRegionFileIfExists(chunkX, chunkZ);
-+        final org.stupidcraft.linearpaper.region.IRegionFile regionFile = this.moonrise$getRegionFileIfExists(chunkX, chunkZ); // DivineMC - Linear region file format
++        final org.bxteam.divinemc.region.IRegionFile regionFile = this.moonrise$getRegionFileIfExists(chunkX, chunkZ); // DivineMC - Linear region file format
  
          final DataInputStream input = regionFile == null ? null : regionFile.getChunkDataInputStream(new ChunkPos(chunkX, chunkZ));
  
@@ -241,7 +241,7 @@ index 16cd10ab8de69ca3d29c84cf93715645322fd72a..1061d1480af0d4947d0f7f1b0028b419
      // Paper end - rewrite chunk system
      // Paper start - rewrite chunk system
 -    public RegionFile getRegionFile(ChunkPos chunkcoordintpair) throws IOException {
-+    public org.stupidcraft.linearpaper.region.IRegionFile getRegionFile(ChunkPos chunkcoordintpair) throws IOException { // DivineMC - Linear region file format
++    public org.bxteam.divinemc.region.IRegionFile getRegionFile(ChunkPos chunkcoordintpair) throws IOException { // DivineMC - Linear region file format
          return this.getRegionFile(chunkcoordintpair, false);
      }
      // Paper end - rewrite chunk system
@@ -250,7 +250,7 @@ index 16cd10ab8de69ca3d29c84cf93715645322fd72a..1061d1480af0d4947d0f7f1b0028b419
      }
  
 -    @org.jetbrains.annotations.Contract("_, false -> !null") @Nullable private RegionFile getRegionFile(ChunkPos chunkPos, boolean existingOnly) throws IOException { // CraftBukkit
-+    @org.jetbrains.annotations.Contract("_, false -> !null") @Nullable private org.stupidcraft.linearpaper.region.IRegionFile getRegionFile(ChunkPos chunkPos, boolean existingOnly) throws IOException { // CraftBukkit // DivineMC - Linear region file format
++    @org.jetbrains.annotations.Contract("_, false -> !null") @Nullable private org.bxteam.divinemc.region.IRegionFile getRegionFile(ChunkPos chunkPos, boolean existingOnly) throws IOException { // CraftBukkit // DivineMC - Linear region file format
          // Paper start - rewrite chunk system
          if (existingOnly) {
              return this.moonrise$getRegionFileIfExists(chunkPos.x, chunkPos.z);
@@ -259,7 +259,7 @@ index 16cd10ab8de69ca3d29c84cf93715645322fd72a..1061d1480af0d4947d0f7f1b0028b419
              final long key = ChunkPos.asLong(chunkPos.x >> REGION_SHIFT, chunkPos.z >> REGION_SHIFT);
  
 -            RegionFile ret = this.regionCache.getAndMoveToFirst(key);
-+            org.stupidcraft.linearpaper.region.IRegionFile ret = this.regionCache.getAndMoveToFirst(key); // DivineMC - Linear region file format
++            org.bxteam.divinemc.region.IRegionFile ret = this.regionCache.getAndMoveToFirst(key); // DivineMC - Linear region file format
              if (ret != null) {
                  return ret;
              }
@@ -268,7 +268,7 @@ index 16cd10ab8de69ca3d29c84cf93715645322fd72a..1061d1480af0d4947d0f7f1b0028b419
              FileUtil.createDirectoriesSafe(this.folder);
  
 -            ret = new RegionFile(this.info, regionPath, this.folder, this.sync);
-+            ret = org.stupidcraft.linearpaper.region.IRegionFileFactory.getAbstractRegionFile(this.info, regionPath, this.folder, this.sync); // DivineMC - Linear region file format
++            ret = org.bxteam.divinemc.region.RegionFileFactory.getAbstractRegionFile(this.info, regionPath, this.folder, this.sync); // DivineMC - Linear region file format
  
              this.regionCache.putAndMoveToFirst(key, ret);
  
@@ -277,7 +277,7 @@ index 16cd10ab8de69ca3d29c84cf93715645322fd72a..1061d1480af0d4947d0f7f1b0028b419
      }
  
 -    private static CompoundTag readOversizedChunk(RegionFile regionfile, ChunkPos chunkCoordinate) throws IOException {
-+    private static CompoundTag readOversizedChunk(org.stupidcraft.linearpaper.region.IRegionFile regionfile, ChunkPos chunkCoordinate) throws IOException { // DivineMC - Linear region file format
++    private static CompoundTag readOversizedChunk(org.bxteam.divinemc.region.IRegionFile regionfile, ChunkPos chunkCoordinate) throws IOException { // DivineMC - Linear region file format
          synchronized (regionfile) {
              try (DataInputStream datainputstream = regionfile.getChunkDataInputStream(chunkCoordinate)) {
                  CompoundTag oversizedData = regionfile.getOversizedData(chunkCoordinate.x, chunkCoordinate.z);
@@ -286,7 +286,7 @@ index 16cd10ab8de69ca3d29c84cf93715645322fd72a..1061d1480af0d4947d0f7f1b0028b419
      public CompoundTag read(ChunkPos chunkPos) throws IOException {
          // CraftBukkit start - SPIGOT-5680: There's no good reason to preemptively create files on read, save that for writing
 -        RegionFile regionFile = this.getRegionFile(chunkPos, true);
-+        org.stupidcraft.linearpaper.region.IRegionFile regionFile = this.getRegionFile(chunkPos, true); // DivineMC - Linear region file format
++        org.bxteam.divinemc.region.IRegionFile regionFile = this.getRegionFile(chunkPos, true); // DivineMC - Linear region file format
          if (regionFile == null) {
              return null;
          }
@@ -295,7 +295,7 @@ index 16cd10ab8de69ca3d29c84cf93715645322fd72a..1061d1480af0d4947d0f7f1b0028b419
      public void scanChunk(ChunkPos chunkPos, StreamTagVisitor visitor) throws IOException {
          // CraftBukkit start - SPIGOT-5680: There's no good reason to preemptively create files on read, save that for writing
 -        RegionFile regionFile = this.getRegionFile(chunkPos, true);
-+        org.stupidcraft.linearpaper.region.IRegionFile regionFile = this.getRegionFile(chunkPos, true); // DivineMC - Linear region file format
++        org.bxteam.divinemc.region.IRegionFile regionFile = this.getRegionFile(chunkPos, true); // DivineMC - Linear region file format
          if (regionFile == null) {
              return;
          }
@@ -304,7 +304,7 @@ index 16cd10ab8de69ca3d29c84cf93715645322fd72a..1061d1480af0d4947d0f7f1b0028b419
  
      public void write(ChunkPos chunkPos, @Nullable CompoundTag chunkData) throws IOException { // Paper - rewrite chunk system - public
 -        RegionFile regionFile = this.getRegionFile(chunkPos, chunkData == null); // CraftBukkit // Paper - rewrite chunk system
-+        org.stupidcraft.linearpaper.region.IRegionFile regionFile = this.getRegionFile(chunkPos, chunkData == null); // CraftBukkit // Paper - rewrite chunk system // DivineMC - Linear region file format
++        org.bxteam.divinemc.region.IRegionFile regionFile = this.getRegionFile(chunkPos, chunkData == null); // CraftBukkit // Paper - rewrite chunk system // DivineMC - Linear region file format
          // Paper start - rewrite chunk system
          if (regionFile == null) {
              // if the RegionFile doesn't exist, no point in deleting from it
@@ -313,7 +313,7 @@ index 16cd10ab8de69ca3d29c84cf93715645322fd72a..1061d1480af0d4947d0f7f1b0028b419
          synchronized (this) {
              final ExceptionCollector<IOException> exceptionCollector = new ExceptionCollector<>();
 -            for (final RegionFile regionFile : this.regionCache.values()) {
-+            for (final org.stupidcraft.linearpaper.region.IRegionFile regionFile : this.regionCache.values()) { // DivineMC - Linear region file format
++            for (final org.bxteam.divinemc.region.IRegionFile regionFile : this.regionCache.values()) { // DivineMC - Linear region file format
                  try {
                      regionFile.close();
                  } catch (final IOException ex) {
@@ -322,7 +322,7 @@ index 16cd10ab8de69ca3d29c84cf93715645322fd72a..1061d1480af0d4947d0f7f1b0028b419
          synchronized (this) {
              final ExceptionCollector<IOException> exceptionCollector = new ExceptionCollector<>();
 -            for (final RegionFile regionFile : this.regionCache.values()) {
-+            for (final org.stupidcraft.linearpaper.region.IRegionFile regionFile : this.regionCache.values()) { // DivineMC - Linear region file format
++            for (final org.bxteam.divinemc.region.IRegionFile regionFile : this.regionCache.values()) { // DivineMC - Linear region file format
                  try {
                      regionFile.flush();
                  } catch (final IOException ex) {

divinemc-server/purpur-patches/features/0002-Add-missing-purpur-config-options.patch

@@ -5,7 +5,7 @@ Subject: [PATCH] Add missing purpur config options
 
 
 diff --git a/src/main/java/org/purpurmc/purpur/PurpurConfig.java b/src/main/java/org/purpurmc/purpur/PurpurConfig.java
-index 168361632d4af27c2144864ade539ce7ea217217..48248e1a7eb9f63220dd619c1868dcca3150c345 100644
+index 554ae05a1a7f7dbe91455cb14b1d9a02f3b7d288..2c32f98e4f3ac2705ae6e95a8e8965b4b9d9a0d5 100644
 --- a/src/main/java/org/purpurmc/purpur/PurpurConfig.java
 +++ b/src/main/java/org/purpurmc/purpur/PurpurConfig.java
 @@ -327,6 +327,7 @@ public class PurpurConfig {
@@ -16,7 +16,7 @@ index 168361632d4af27c2144864ade539ce7ea217217..48248e1a7eb9f63220dd619c1868dcca
      public static boolean enderChestSixRows = false;
      public static boolean enderChestPermissionRows = false;
      public static boolean cryingObsidianValidForPortalFrame = false;
-@@ -369,6 +370,7 @@ public class PurpurConfig {
+@@ -370,6 +371,7 @@ public class PurpurConfig {
              case 1 -> 9;
              default -> 27;
          });

divinemc-server/src/main/java/org/bxteam/divinemc/DivineConfig.java

@@ -10,13 +10,14 @@ import org.apache.logging.log4j.Logger;
 import org.bukkit.configuration.ConfigurationSection;
 import org.bukkit.configuration.MemoryConfiguration;
 import org.bxteam.divinemc.entity.pathfinding.PathfindTaskRejectPolicy;
+import org.bxteam.divinemc.region.LinearImplementation;
 import org.bxteam.divinemc.server.chunk.ChunkSystemAlgorithms;
 import org.bxteam.divinemc.server.chunk.ChunkTaskPriority;
 import org.jetbrains.annotations.Nullable;
 import org.simpleyaml.configuration.comments.CommentType;
 import org.simpleyaml.configuration.file.YamlFile;
 import org.simpleyaml.exceptions.InvalidConfigurationException;
-import org.stupidcraft.linearpaper.region.EnumRegionFileExtension;
+import org.bxteam.divinemc.region.RegionFileFormat;
 
 import java.io.File;
 import java.io.IOException;
@@ -526,32 +527,50 @@ public class DivineConfig {
         if (asyncEntityTrackerQueueSize <= 0) asyncEntityTrackerQueueSize = asyncEntityTrackerMaxThreads * 384;
     }
 
-    public static EnumRegionFileExtension regionFormatTypeName = EnumRegionFileExtension.MCA;
+    public static RegionFileFormat regionFormatTypeName = RegionFileFormat.ANVIL;
+    public static LinearImplementation linearImplementation = LinearImplementation.V2;
+    public static int linearFlushMaxThreads = 4;
+    public static int linearFlushDelay = 100;
+    public static boolean linearUseVirtualThread = false;
     public static int linearCompressionLevel = 1;
-    public static int linearFlushFrequency = 5;
     private static void linearRegionFormat() {
-        regionFormatTypeName = EnumRegionFileExtension.fromName(getString("settings.linear-region-format.type", regionFormatTypeName.name(),
+        regionFormatTypeName = RegionFileFormat.fromName(getString("settings.linear-region-format.type", regionFormatTypeName.name(),
             "The type of region file format to use for storing chunk data.",
             "Valid values:",
             " - LINEAR: Linear region file format",
-            " - MCA: Anvil region file format (default)"));
+            " - ANVIL: Anvil region file format (default)"));
+        linearImplementation = LinearImplementation.valueOf(getString("settings.linear-region-format.implementation", linearImplementation.name(),
+            "The implementation of the linear region file format to use.",
+            "Valid values:",
+            " - V1: Basic and default linear implementation",
+            " - V2: Introduces a grid-based compression scheme for better data management and flexibility (default)"));
+
+        linearFlushMaxThreads = getInt("settings.linear-region-format.flush-max-threads", linearFlushMaxThreads,
+            "The maximum number of threads to use for flushing linear region files.",
+            "If this value is less than or equal to 0, it will be set to the number of available processors + this value.");
+        linearFlushDelay = getInt("settings.linear-region-format.flush-delay", linearFlushDelay,
+            "The delay in milliseconds to wait before flushing next files.");
+        linearUseVirtualThread = getBoolean("settings.linear-region-format.use-virtual-thread", linearUseVirtualThread,
+            "Whether to use virtual threads for flushing.");
         linearCompressionLevel = getInt("settings.linear-region-format.compression-level", linearCompressionLevel,
             "The compression level to use for the linear region file format.");
-        linearFlushFrequency = getInt("settings.linear-region-format.flush-frequency", linearFlushFrequency,
-            "The frequency in seconds to flush the linear region file format.");
 
         setComment("settings.linear-region-format",
-            "The linear region file format is a custom region file format that is designed to be more efficient than the MCA format.",
+            "The linear region file format is a custom region file format that is designed to be more efficient than the ANVIL format.",
             "It uses uses ZSTD compression instead of ZLIB. This format saves about 50% of disk space.",
             "Read more information about linear region format at https://github.com/xymb-endcrystalme/LinearRegionFileFormatTools",
             "WARNING: If you are want to use this format, make sure to create backup of your world before switching to it, there is potential risk to lose chunk data.");
 
-        if (regionFormatTypeName == EnumRegionFileExtension.UNKNOWN) {
+        if (regionFormatTypeName == RegionFileFormat.UNKNOWN) {
-            LOGGER.error("Unknown region file type: {}, falling back to MCA format.", regionFormatTypeName);
+            LOGGER.error("Unknown region file type: {}, falling back to ANVIL format.", regionFormatTypeName);
-            regionFormatTypeName = EnumRegionFileExtension.MCA;
+            regionFormatTypeName = RegionFileFormat.ANVIL;
         }
 
-        if (linearCompressionLevel > 23 || linearCompressionLevel < 1) {
+        if (linearFlushMaxThreads <= 0) {
+            linearFlushMaxThreads = Math.max(Runtime.getRuntime().availableProcessors() + linearFlushMaxThreads, 1);
+        }
+
+        if (linearCompressionLevel > 22 || linearCompressionLevel < 1) {
             LOGGER.warn("Invalid linear compression level: {}, resetting to default (1)", playerNearChunkDetectionRange);
             linearCompressionLevel = 1;
         }

divinemc-server/src/main/java/org/bxteam/divinemc/region/IRegionFile.java

@@ -1,4 +1,4 @@
-package org.stupidcraft.linearpaper.region;
+package org.bxteam.divinemc.region;
 
 import ca.spottedleaf.moonrise.patches.chunk_system.storage.ChunkSystemRegionFile;
 import net.minecraft.nbt.CompoundTag;

divinemc-server/src/main/java/org/bxteam/divinemc/region/LinearImplementation.java

@@ -0,0 +1,6 @@
+package org.bxteam.divinemc.region;
+
+public enum LinearImplementation {
+    V1,
+    V2
+}

divinemc-server/src/main/java/org/bxteam/divinemc/region/LinearRegionFile.java

@@ -0,0 +1,659 @@
+package org.bxteam.divinemc.region;
+
+import ca.spottedleaf.moonrise.patches.chunk_system.io.MoonriseRegionFileIO;
+import com.github.luben.zstd.ZstdInputStream;
+import com.github.luben.zstd.ZstdOutputStream;
+import com.mojang.logging.LogUtils;
+import net.jpountz.lz4.LZ4Compressor;
+import net.jpountz.lz4.LZ4Factory;
+import net.jpountz.lz4.LZ4FastDecompressor;
+import net.minecraft.nbt.CompoundTag;
+import net.minecraft.world.level.ChunkPos;
+import net.openhft.hashing.LongHashFunction;
+import org.bxteam.divinemc.DivineConfig;
+import org.bxteam.divinemc.spark.ThreadDumperRegistry;
+import org.jspecify.annotations.Nullable;
+import org.slf4j.Logger;
+
+import java.io.BufferedOutputStream;
+import java.io.ByteArrayInputStream;
+import java.io.ByteArrayOutputStream;
+import java.io.DataInputStream;
+import java.io.DataOutputStream;
+import java.io.File;
+import java.io.FileOutputStream;
+import java.io.IOException;
+import java.io.InputStream;
+import java.nio.ByteBuffer;
+import java.nio.file.Files;
+import java.nio.file.Path;
+import java.nio.file.StandardCopyOption;
+import java.util.ArrayList;
+import java.util.concurrent.TimeUnit;
+import java.util.concurrent.locks.LockSupport;
+
+public class LinearRegionFile implements IRegionFile {
+    public static final int MAX_CHUNK_SIZE = 500 * 1024 * 1024;
+    private static final Object SAVE_LOCK = new Object();
+    private static final long SUPERBLOCK = 0xc3ff13183cca9d9aL;
+    private static final Logger LOGGER = LogUtils.getLogger();
+
+    private static final byte V1_VERSION = 2;
+    private static final byte V2_VERSION = 3;
+
+    private byte[][] bucketBuffers;
+    private final byte[][] chunkCompressedBuffers = new byte[1024][];
+    private final int[] chunkUncompressedSizes = new int[1024];
+    private final long[] chunkTimestamps = new long[1024];
+
+    private final Object markedToSaveLock = new Object();
+    private boolean markedToSave = false;
+
+    private final LZ4Compressor compressor;
+    private final LZ4FastDecompressor decompressor;
+
+    private volatile boolean regionFileOpen = false;
+    private volatile boolean close = false;
+
+    private final Path regionFilePath;
+    private final int gridSizeDefault = 8;
+    private int gridSize = gridSizeDefault;
+    private int bucketSize = 4;
+    private final int compressionLevel;
+    private final LinearImplementation linearImpl;
+    private final Thread schedulingThread;
+
+    private static int activeSaveThreads = 0;
+
+    public LinearRegionFile(Path path, LinearImplementation linearImplementation, int compressionLevel) {
+        this.regionFilePath = path;
+        this.linearImpl = linearImplementation;
+        this.compressionLevel = compressionLevel;
+        this.compressor = LZ4Factory.fastestInstance().fastCompressor();
+        this.decompressor = LZ4Factory.fastestInstance().fastDecompressor();
+
+        Runnable flushCheck = () -> {
+            while (!close) {
+                synchronized (SAVE_LOCK) {
+                    if (markedToSave && activeSaveThreads < DivineConfig.linearFlushMaxThreads) {
+                        activeSaveThreads++;
+                        Runnable flushOperation = () -> {
+                            try {
+                                flush();
+                            } catch (IOException ex) {
+                                LOGGER.error("Region file {} flush failed", regionFilePath.toAbsolutePath(), ex);
+                            } finally {
+                                synchronized (SAVE_LOCK) {
+                                    activeSaveThreads--;
+                                }
+                            }
+                        };
+                        Thread saveThread = DivineConfig.linearUseVirtualThread
+                            ? Thread.ofVirtual().name("Linear IO - " + this.hashCode()).unstarted(flushOperation)
+                            : Thread.ofPlatform().name("Linear IO - " + this.hashCode()).unstarted(flushOperation);
+                        saveThread.setPriority(Thread.NORM_PRIORITY - 3);
+                        saveThread.start();
+                        ThreadDumperRegistry.REGISTRY.add(saveThread.getName());
+                    }
+                }
+                LockSupport.parkNanos(TimeUnit.MILLISECONDS.toNanos(DivineConfig.linearFlushDelay));
+            }
+        };
+        this.schedulingThread = DivineConfig.linearUseVirtualThread
+            ? Thread.ofVirtual().unstarted(flushCheck)
+            : Thread.ofPlatform().unstarted(flushCheck);
+        this.schedulingThread.setName("Linear IO Schedule - " + this.hashCode());
+        ThreadDumperRegistry.REGISTRY.add(this.schedulingThread.getName());
+    }
+
+    private synchronized void openRegionFile() {
+        if (regionFileOpen) return;
+        regionFileOpen = true;
+
+        File file = regionFilePath.toFile();
+        if (!file.canRead()) {
+            schedulingThread.start();
+            return;
+        }
+
+        try {
+            byte[] fileContent = Files.readAllBytes(regionFilePath);
+            ByteBuffer byteBuffer = ByteBuffer.wrap(fileContent);
+
+            long superBlock = byteBuffer.getLong();
+            if (superBlock != SUPERBLOCK) {
+                throw new RuntimeException("Invalid superblock: " + superBlock + " file " + regionFilePath);
+            }
+
+            byte version = byteBuffer.get();
+            if (version == V1_VERSION) {
+                parseLinearV1(byteBuffer);
+            } else if (version == V2_VERSION) {
+                parseLinearV2(byteBuffer);
+            } else {
+                throw new RuntimeException("Invalid version: " + version + " file " + regionFilePath);
+            }
+
+            schedulingThread.start();
+        } catch (IOException e) {
+            throw new RuntimeException("Failed to open region file " + regionFilePath, e);
+        }
+    }
+
+    private void parseLinearV1(ByteBuffer buffer) throws IOException {
+        final int HEADER_SIZE = 32;
+        final int FOOTER_SIZE = 8;
+        buffer.position(buffer.position() + 11);
+
+        int dataCount = buffer.getInt();
+        long fileLength = regionFilePath.toFile().length();
+        if (fileLength != HEADER_SIZE + dataCount + FOOTER_SIZE) {
+            throw new IOException("Invalid file length: " + regionFilePath + " " + fileLength + " expected " + (HEADER_SIZE + dataCount + FOOTER_SIZE));
+        }
+
+        buffer.position(buffer.position() + 8);
+
+        byte[] rawCompressed = new byte[dataCount];
+        buffer.get(rawCompressed);
+
+        try (ByteArrayInputStream bais = new ByteArrayInputStream(rawCompressed);
+             ZstdInputStream zstdIn = new ZstdInputStream(bais)) {
+            ByteBuffer decompressedBuffer = ByteBuffer.wrap(zstdIn.readAllBytes());
+            int[] starts = new int[1024];
+            for (int i = 0; i < 1024; i++) {
+                starts[i] = decompressedBuffer.getInt();
+                decompressedBuffer.getInt();
+            }
+
+            for (int i = 0; i < 1024; i++) {
+                if (starts[i] > 0) {
+                    int size = starts[i];
+                    byte[] chunkData = new byte[size];
+                    decompressedBuffer.get(chunkData);
+
+                    int maxCompressedLength = compressor.maxCompressedLength(size);
+                    byte[] compressed = new byte[maxCompressedLength];
+                    int compressedLength = compressor.compress(chunkData, 0, size, compressed, 0, maxCompressedLength);
+                    byte[] finalCompressed = new byte[compressedLength];
+                    System.arraycopy(compressed, 0, finalCompressed, 0, compressedLength);
+
+                    chunkCompressedBuffers[i] = finalCompressed;
+                    chunkUncompressedSizes[i] = size;
+                    chunkTimestamps[i] = currentTimestamp();
+                }
+            }
+        }
+    }
+
+    private void parseLinearV2(ByteBuffer buffer) throws IOException {
+        buffer.getLong();
+        gridSize = buffer.get();
+        if (!(gridSize == 1 || gridSize == 2 || gridSize == 4 || gridSize == 8 || gridSize == 16 || gridSize == 32)) {
+            throw new RuntimeException("Invalid grid size: " + gridSize + " file " + regionFilePath);
+        }
+        bucketSize = 32 / gridSize;
+
+        buffer.getInt();
+        buffer.getInt();
+
+        boolean[] chunkExistenceBitmap = deserializeExistenceBitmap(buffer);
+
+        while (true) {
+            byte featureNameLength = buffer.get();
+            if (featureNameLength == 0) break;
+            byte[] featureNameBytes = new byte[featureNameLength];
+            buffer.get(featureNameBytes);
+            String featureName = new String(featureNameBytes);
+            int featureValue = buffer.getInt();
+        }
+
+        int bucketCount = gridSize * gridSize;
+        int[] bucketSizes = new int[bucketCount];
+        byte[] bucketCompressionLevels = new byte[bucketCount];
+        long[] bucketHashes = new long[bucketCount];
+
+        for (int i = 0; i < bucketCount; i++) {
+            bucketSizes[i] = buffer.getInt();
+            bucketCompressionLevels[i] = buffer.get();
+            bucketHashes[i] = buffer.getLong();
+        }
+
+        bucketBuffers = new byte[bucketCount][];
+        for (int i = 0; i < bucketCount; i++) {
+            if (bucketSizes[i] > 0) {
+                bucketBuffers[i] = new byte[bucketSizes[i]];
+                buffer.get(bucketBuffers[i]);
+                long rawHash = LongHashFunction.xx().hashBytes(bucketBuffers[i]);
+                if (rawHash != bucketHashes[i]) {
+                    throw new IOException("Region file hash incorrect " + regionFilePath);
+                }
+            }
+        }
+
+        long footerSuperBlock = buffer.getLong();
+        if (footerSuperBlock != SUPERBLOCK) {
+            throw new IOException("Footer superblock invalid " + regionFilePath);
+        }
+    }
+
+    private synchronized void markToSave() {
+        synchronized (markedToSaveLock) {
+            markedToSave = true;
+        }
+    }
+
+    private synchronized boolean isMarkedToSave() {
+        synchronized (markedToSaveLock) {
+            if (markedToSave) {
+                markedToSave = false;
+                return true;
+            }
+            return false;
+        }
+    }
+
+    @Override
+    public synchronized boolean doesChunkExist(ChunkPos pos) {
+        openRegionFile();
+        return hasChunk(pos);
+    }
+
+    @Override
+    public synchronized boolean hasChunk(ChunkPos pos) {
+        openRegionFile();
+        openBucketForChunk(pos.x, pos.z);
+        int index = getChunkIndex(pos.x, pos.z);
+        return chunkUncompressedSizes[index] > 0;
+    }
+
+    @Override
+    public synchronized void flush() throws IOException {
+        if (!isMarkedToSave()) return;
+        openRegionFile();
+        if (linearImpl == LinearImplementation.V1) {
+            flushLinearV1();
+        } else if (linearImpl == LinearImplementation.V2) {
+            flushLinearV2();
+        }
+    }
+
+    private void flushLinearV1() throws IOException {
+        long timestamp = currentTimestamp();
+        short chunkCount = 0;
+        File tempFile = new File(regionFilePath.toString() + ".tmp");
+
+        try (FileOutputStream fos = new FileOutputStream(tempFile);
+             ByteArrayOutputStream zstdBAOS = new ByteArrayOutputStream();
+             ZstdOutputStream zstdOut = new ZstdOutputStream(zstdBAOS, compressionLevel);
+             DataOutputStream zstdDataOut = new DataOutputStream(zstdOut);
+             DataOutputStream fileDataOut = new DataOutputStream(fos)) {
+
+            fileDataOut.writeLong(SUPERBLOCK);
+            fileDataOut.writeByte(V1_VERSION);
+            fileDataOut.writeLong(timestamp);
+            fileDataOut.writeByte(compressionLevel);
+
+            ArrayList<byte[]> decompressedChunks = new ArrayList<>(1024);
+            for (int i = 0; i < 1024; i++) {
+                if (chunkUncompressedSizes[i] != 0) {
+                    chunkCount++;
+                    byte[] decompressed = new byte[chunkUncompressedSizes[i]];
+                    decompressor.decompress(chunkCompressedBuffers[i], 0, decompressed, 0, chunkUncompressedSizes[i]);
+                    decompressedChunks.add(decompressed);
+                } else {
+                    decompressedChunks.add(null);
+                }
+            }
+
+            for (int i = 0; i < 1024; i++) {
+                zstdDataOut.writeInt(chunkUncompressedSizes[i]);
+                zstdDataOut.writeInt((int) chunkTimestamps[i]);
+            }
+
+            for (int i = 0; i < 1024; i++) {
+                if (decompressedChunks.get(i) != null) {
+                    zstdDataOut.write(decompressedChunks.get(i));
+                }
+            }
+            zstdDataOut.close();
+
+            fileDataOut.writeShort(chunkCount);
+            byte[] compressedZstdData = zstdBAOS.toByteArray();
+            fileDataOut.writeInt(compressedZstdData.length);
+            fileDataOut.writeLong(0);
+            fileDataOut.write(compressedZstdData);
+            fileDataOut.writeLong(SUPERBLOCK);
+
+            fileDataOut.flush();
+            fos.getFD().sync();
+            fos.getChannel().force(true);
+        }
+        Files.move(tempFile.toPath(), regionFilePath, StandardCopyOption.REPLACE_EXISTING);
+    }
+
+    private void flushLinearV2() throws IOException {
+        long timestamp = currentTimestamp();
+        File tempFile = new File(regionFilePath.toString() + ".tmp");
+
+        try (FileOutputStream fos = new FileOutputStream(tempFile);
+             DataOutputStream dataOut = new DataOutputStream(fos)) {
+
+            dataOut.writeLong(SUPERBLOCK);
+            dataOut.writeByte(V2_VERSION);
+            dataOut.writeLong(timestamp);
+            dataOut.writeByte(gridSize);
+
+            int[] regionCoords = parseRegionCoordinates(regionFilePath.getFileName().toString());
+            dataOut.writeInt(regionCoords[0]);
+            dataOut.writeInt(regionCoords[1]);
+
+            boolean[] chunkExistence = new boolean[1024];
+            for (int i = 0; i < 1024; i++) {
+                chunkExistence[i] = (chunkUncompressedSizes[i] > 0);
+            }
+            writeExistenceBitmap(dataOut, chunkExistence);
+
+            writeNBTFeatures(dataOut);
+
+            byte[][] buckets = buildBuckets();
+
+            int bucketCount = gridSize * gridSize;
+            for (int i = 0; i < bucketCount; i++) {
+                dataOut.writeInt(buckets[i] != null ? buckets[i].length : 0);
+                dataOut.writeByte(compressionLevel);
+                long bucketHash = buckets[i] != null ? LongHashFunction.xx().hashBytes(buckets[i]) : 0;
+                dataOut.writeLong(bucketHash);
+            }
+            for (int i = 0; i < bucketCount; i++) {
+                if (buckets[i] != null) {
+                    dataOut.write(buckets[i]);
+                }
+            }
+            dataOut.writeLong(SUPERBLOCK);
+
+            dataOut.flush();
+            fos.getFD().sync();
+            fos.getChannel().force(true);
+        }
+        Files.move(tempFile.toPath(), regionFilePath, StandardCopyOption.REPLACE_EXISTING);
+    }
+
+    private void writeNBTFeatures(DataOutputStream dataOut) throws IOException {
+        dataOut.writeByte(0);
+    }
+
+    private byte[][] buildBuckets() throws IOException {
+        int bucketCount = gridSize * gridSize;
+        byte[][] buckets = new byte[bucketCount][];
+
+        for (int bx = 0; bx < gridSize; bx++) {
+            for (int bz = 0; bz < gridSize; bz++) {
+                int bucketIdx = bx * gridSize + bz;
+                if (bucketBuffers != null && bucketBuffers[bucketIdx] != null) {
+                    buckets[bucketIdx] = bucketBuffers[bucketIdx];
+                    continue;
+                }
+
+                try (ByteArrayOutputStream bucketBAOS = new ByteArrayOutputStream();
+                     ZstdOutputStream bucketZstdOut = new ZstdOutputStream(bucketBAOS, compressionLevel);
+                     DataOutputStream bucketDataOut = new DataOutputStream(bucketZstdOut)) {
+
+                    boolean hasData = false;
+                    int cellCount = 32 / gridSize;
+                    for (int cx = 0; cx < cellCount; cx++) {
+                        for (int cz = 0; cz < cellCount; cz++) {
+                            int chunkIndex = (bx * cellCount + cx) + (bz * cellCount + cz) * 32;
+                            if (chunkUncompressedSizes[chunkIndex] > 0) {
+                                hasData = true;
+                                byte[] chunkData = new byte[chunkUncompressedSizes[chunkIndex]];
+                                decompressor.decompress(chunkCompressedBuffers[chunkIndex], 0, chunkData, 0, chunkUncompressedSizes[chunkIndex]);
+                                bucketDataOut.writeInt(chunkData.length + 8);
+                                bucketDataOut.writeLong(chunkTimestamps[chunkIndex]);
+                                bucketDataOut.write(chunkData);
+                            } else {
+                                bucketDataOut.writeInt(0);
+                                bucketDataOut.writeLong(chunkTimestamps[chunkIndex]);
+                            }
+                        }
+                    }
+                    bucketDataOut.close();
+                    if (hasData) {
+                        buckets[bucketIdx] = bucketBAOS.toByteArray();
+                    }
+                }
+            }
+        }
+        return buckets;
+    }
+
+    private void openBucketForChunk(int chunkX, int chunkZ) {
+        int modX = Math.floorMod(chunkX, 32);
+        int modZ = Math.floorMod(chunkZ, 32);
+        int bucketIdx = chunkToBucketIndex(modX, modZ);
+        if (bucketBuffers == null || bucketBuffers[bucketIdx] == null) {
+            return;
+        }
+
+        try (ByteArrayInputStream bucketBAIS = new ByteArrayInputStream(bucketBuffers[bucketIdx]);
+             ZstdInputStream bucketZstdIn = new ZstdInputStream(bucketBAIS)) {
+
+            ByteBuffer bucketBuffer = ByteBuffer.wrap(bucketZstdIn.readAllBytes());
+            int cellsPerBucket = 32 / gridSize;
+            int bx = modX / bucketSize, bz = modZ / bucketSize;
+            for (int cx = 0; cx < cellsPerBucket; cx++) {
+                for (int cz = 0; cz < cellsPerBucket; cz++) {
+                    int chunkIndex = (bx * cellsPerBucket + cx) + (bz * cellsPerBucket + cz) * 32;
+                    int chunkSize = bucketBuffer.getInt();
+                    long timestamp = bucketBuffer.getLong();
+                    chunkTimestamps[chunkIndex] = timestamp;
+
+                    if (chunkSize > 0) {
+                        byte[] chunkData = new byte[chunkSize - 8];
+                        bucketBuffer.get(chunkData);
+
+                        int maxCompressedLength = compressor.maxCompressedLength(chunkData.length);
+                        byte[] compressed = new byte[maxCompressedLength];
+                        int compressedLength = compressor.compress(chunkData, 0, chunkData.length, compressed, 0, maxCompressedLength);
+                        byte[] finalCompressed = new byte[compressedLength];
+                        System.arraycopy(compressed, 0, finalCompressed, 0, compressedLength);
+
+                        chunkCompressedBuffers[chunkIndex] = finalCompressed;
+                        chunkUncompressedSizes[chunkIndex] = chunkData.length;
+                    }
+                }
+            }
+        } catch (IOException ex) {
+            throw new RuntimeException("Region file corrupted: " + regionFilePath + " bucket: " + bucketIdx, ex);
+        }
+        bucketBuffers[bucketIdx] = null;
+    }
+
+    @Override
+    public synchronized void write(ChunkPos pos, ByteBuffer buffer) {
+        openRegionFile();
+        openBucketForChunk(pos.x, pos.z);
+        try {
+            byte[] rawData = toByteArray(new ByteArrayInputStream(buffer.array()));
+            int uncompressedSize = rawData.length;
+            if (uncompressedSize > MAX_CHUNK_SIZE) {
+                LOGGER.error("Chunk dupe attempt {}", regionFilePath);
+                clear(pos);
+            } else {
+                int maxCompressedLength = compressor.maxCompressedLength(uncompressedSize);
+                byte[] compressed = new byte[maxCompressedLength];
+                int compressedLength = compressor.compress(rawData, 0, uncompressedSize, compressed, 0, maxCompressedLength);
+                byte[] finalCompressed = new byte[compressedLength];
+                System.arraycopy(compressed, 0, finalCompressed, 0, compressedLength);
+
+                int index = getChunkIndex(pos.x, pos.z);
+                chunkCompressedBuffers[index] = finalCompressed;
+                chunkTimestamps[index] = currentTimestamp();
+                chunkUncompressedSizes[index] = uncompressedSize;
+            }
+        } catch (IOException e) {
+            LOGGER.error("Chunk write IOException {} {}", e, regionFilePath);
+        }
+        markToSave();
+    }
+
+    @Override
+    public DataOutputStream getChunkDataOutputStream(ChunkPos pos) {
+        openRegionFile();
+        openBucketForChunk(pos.x, pos.z);
+        return new DataOutputStream(new BufferedOutputStream(new ChunkBuffer(pos)));
+    }
+
+    @Override
+    public MoonriseRegionFileIO.RegionDataController.WriteData moonrise$startWrite(CompoundTag data, ChunkPos pos) {
+        DataOutputStream out = getChunkDataOutputStream(pos);
+        return new ca.spottedleaf.moonrise.patches.chunk_system.io.MoonriseRegionFileIO.RegionDataController.WriteData(
+            data,
+            ca.spottedleaf.moonrise.patches.chunk_system.io.MoonriseRegionFileIO.RegionDataController.WriteData.WriteResult.WRITE,
+            out,
+            regionFile -> {
+                try {
+                    out.close();
+                } catch (IOException e) {
+                    LOGGER.error("Failed to close region file stream", e);
+                }
+            }
+        );
+    }
+
+    private class ChunkBuffer extends ByteArrayOutputStream {
+        private final ChunkPos pos;
+        public ChunkBuffer(ChunkPos pos) {
+            super();
+            this.pos = pos;
+        }
+        @Override
+        public void close() {
+            ByteBuffer byteBuffer = ByteBuffer.wrap(this.buf, 0, this.count);
+            LinearRegionFile.this.write(this.pos, byteBuffer);
+        }
+    }
+
+    private byte[] toByteArray(InputStream in) throws IOException {
+        ByteArrayOutputStream out = new ByteArrayOutputStream();
+        byte[] tempBuffer = new byte[4096];
+        int length;
+        while ((length = in.read(tempBuffer)) >= 0) {
+            out.write(tempBuffer, 0, length);
+        }
+        return out.toByteArray();
+    }
+
+    @Nullable
+    @Override
+    public synchronized DataInputStream getChunkDataInputStream(ChunkPos pos) {
+        openRegionFile();
+        openBucketForChunk(pos.x, pos.z);
+        int index = getChunkIndex(pos.x, pos.z);
+        if (chunkUncompressedSizes[index] != 0) {
+            byte[] decompressed = new byte[chunkUncompressedSizes[index]];
+            decompressor.decompress(chunkCompressedBuffers[index], 0, decompressed, 0, chunkUncompressedSizes[index]);
+            return new DataInputStream(new ByteArrayInputStream(decompressed));
+        }
+        return null;
+    }
+
+    @Override
+    public synchronized void clear(ChunkPos pos) {
+        openRegionFile();
+        openBucketForChunk(pos.x, pos.z);
+        int index = getChunkIndex(pos.x, pos.z);
+        chunkCompressedBuffers[index] = null;
+        chunkUncompressedSizes[index] = 0;
+        chunkTimestamps[index] = 0;
+        markToSave();
+    }
+
+    @Override
+    public synchronized void close() throws IOException {
+        openRegionFile();
+        close = true;
+        try {
+            flush();
+        } catch (IOException e) {
+            throw new IOException("Region flush IOException " + e + " " + regionFilePath, e);
+        }
+    }
+
+    private static int getChunkIndex(int x, int z) {
+        return (x & 31) + ((z & 31) << 5);
+    }
+
+    private static int currentTimestamp() {
+        return (int) (System.currentTimeMillis() / 1000L);
+    }
+
+    @Override
+    public boolean recalculateHeader() {
+        return false;
+    }
+
+    @Override
+    public void setOversized(int x, int z, boolean something) {
+        // stub
+    }
+
+    @Override
+    public CompoundTag getOversizedData(int x, int z) throws IOException {
+        throw new IOException("getOversizedData is a stub " + regionFilePath);
+    }
+
+    @Override
+    public boolean isOversized(int x, int z) {
+        return false;
+    }
+
+    @Override
+    public Path getPath() {
+        return regionFilePath;
+    }
+
+    private boolean[] deserializeExistenceBitmap(ByteBuffer buffer) {
+        boolean[] result = new boolean[1024];
+        for (int i = 0; i < 128; i++) {
+            byte b = buffer.get();
+            for (int j = 0; j < 8; j++) {
+                result[i * 8 + j] = ((b >> (7 - j)) & 1) == 1;
+            }
+        }
+        return result;
+    }
+
+    private void writeExistenceBitmap(DataOutputStream out, boolean[] bitmap) throws IOException {
+        for (int i = 0; i < 128; i++) {
+            byte b = 0;
+            for (int j = 0; j < 8; j++) {
+                if (bitmap[i * 8 + j]) {
+                    b |= (1 << (7 - j));
+                }
+            }
+            out.writeByte(b);
+        }
+    }
+
+    private int chunkToBucketIndex(int chunkX, int chunkZ) {
+        int bx = chunkX / bucketSize, bz = chunkZ / bucketSize;
+        return bx * gridSize + bz;
+    }
+
+    private int[] parseRegionCoordinates(String fileName) {
+        int regionX = 0;
+        int regionZ = 0;
+        String[] parts = fileName.split("\\.");
+        if (parts.length >= 4) {
+            try {
+                regionX = Integer.parseInt(parts[1]);
+                regionZ = Integer.parseInt(parts[2]);
+            } catch (NumberFormatException e) {
+                LOGGER.error("Failed to parse region coordinates from file name: {}", fileName, e);
+            }
+        } else {
+            LOGGER.warn("Unexpected file name format: {}", fileName);
+        }
+        return new int[]{regionX, regionZ};
+    }
+}

divinemc-server/src/main/java/org/bxteam/divinemc/region/RegionFileFactory.java

@@ -1,4 +1,4 @@
-package org.stupidcraft.linearpaper.region;
+package org.bxteam.divinemc.region;
 
 import net.minecraft.world.level.chunk.storage.RegionFile;
 import net.minecraft.world.level.chunk.storage.RegionFileVersion;
@@ -10,34 +10,20 @@ import org.jetbrains.annotations.NotNull;
 import java.io.IOException;
 import java.nio.file.Path;
 
-public class IRegionFileFactory {
+public class RegionFileFactory {
     @Contract("_, _, _, _ -> new")
     public static @NotNull IRegionFile getAbstractRegionFile(RegionStorageInfo storageKey, Path directory, Path path, boolean dsync) throws IOException {
         return getAbstractRegionFile(storageKey, directory, path, RegionFileVersion.getCompressionFormat(), dsync);
     }
 
     @Contract("_, _, _, _, _ -> new")
-    public static @NotNull IRegionFile getAbstractRegionFile(RegionStorageInfo storageKey, Path directory, Path path, boolean dsync, boolean canRecalcHeader) throws IOException {
+    public static @NotNull IRegionFile getAbstractRegionFile(RegionStorageInfo storageKey, @NotNull Path path, Path directory, RegionFileVersion compressionFormat, boolean dsync) throws IOException {
-        return getAbstractRegionFile(storageKey, directory, path, RegionFileVersion.getCompressionFormat(), dsync, canRecalcHeader);
-    }
-
-    @Contract("_, _, _, _, _ -> new")
-    public static @NotNull IRegionFile getAbstractRegionFile(RegionStorageInfo storageKey, Path path, Path directory, RegionFileVersion compressionFormat, boolean dsync) throws IOException {
-        return getAbstractRegionFile(storageKey, path, directory, compressionFormat, dsync, true);
-    }
-
-    @Contract("_, _, _, _, _, _ -> new")
-    public static @NotNull IRegionFile getAbstractRegionFile(RegionStorageInfo storageKey, @NotNull Path path, Path directory, RegionFileVersion compressionFormat, boolean dsync, boolean canRecalcHeader) throws IOException {
         final String fullFileName = path.getFileName().toString();
         final String[] fullNameSplit = fullFileName.split("\\.");
         final String extensionName = fullNameSplit[fullNameSplit.length - 1];
-        switch (EnumRegionFileExtension.fromExtension(extensionName)) {
+        switch (RegionFileFormat.fromExtension(extensionName)) {
-            case UNKNOWN -> {
-                return new RegionFile(storageKey, path, directory, compressionFormat, dsync);
-            }
-
             case LINEAR -> {
-                return new LinearRegionFile(path, DivineConfig.linearCompressionLevel);
+                return new LinearRegionFile(path, DivineConfig.linearImplementation, DivineConfig.linearCompressionLevel);
             }
 
             default -> {

divinemc-server/src/main/java/org/bxteam/divinemc/region/RegionFileFormat.java

@@ -1,46 +1,46 @@
-package org.stupidcraft.linearpaper.region;
+package org.bxteam.divinemc.region;
 
 import org.jetbrains.annotations.Contract;
 import org.jetbrains.annotations.NotNull;
-
 import java.util.Locale;
 
-public enum EnumRegionFileExtension {
+public enum RegionFileFormat {
     LINEAR(".linear"),
-    MCA(".mca"),
+    ANVIL(".mca"),
     UNKNOWN(null);
 
-    private final String extensionName;
+    private final String extension;
 
-    EnumRegionFileExtension(String extensionName) {
+    RegionFileFormat(String extension) {
-        this.extensionName = extensionName;
+        this.extension = extension;
     }
 
     public String getExtensionName() {
-        return this.extensionName;
+        return this.extension;
     }
 
     @Contract(pure = true)
-    public static EnumRegionFileExtension fromName(@NotNull String name) {
+    public static RegionFileFormat fromName(@NotNull String name) {
         switch (name.toUpperCase(Locale.ROOT)) {
-            case "MCA" -> {
+            case "MCA", "ANVIL" -> {
-                return MCA;
+                return ANVIL;
             }
 
             case "LINEAR" -> {
                 return LINEAR;
             }
+
             default -> {
-                return UNKNOWN;
+                throw new IllegalArgumentException("Unknown region file format: " + name);
             }
         }
     }
 
     @Contract(pure = true)
-    public static EnumRegionFileExtension fromExtension(@NotNull String name) {
+    public static RegionFileFormat fromExtension(@NotNull String name) {
         switch (name.toLowerCase()) {
-            case "mca" -> {
+            case "mca", "anvil" -> {
-                return MCA;
+                return ANVIL;
             }
 
             case "linear" -> {

divinemc-server/src/main/java/org/stupidcraft/linearpaper/region/LinearRegionFile.java

@@ -1,308 +0,0 @@
-package org.stupidcraft.linearpaper.region;
-
-import ca.spottedleaf.moonrise.patches.chunk_system.io.MoonriseRegionFileIO;
-import com.github.luben.zstd.ZstdInputStream;
-import com.github.luben.zstd.ZstdOutputStream;
-import com.mojang.logging.LogUtils;
-import net.jpountz.lz4.LZ4Compressor;
-import net.jpountz.lz4.LZ4Factory;
-import net.jpountz.lz4.LZ4FastDecompressor;
-import net.minecraft.nbt.CompoundTag;
-import net.minecraft.world.level.ChunkPos;
-import org.bxteam.divinemc.DivineConfig;
-import org.slf4j.Logger;
-
-import java.io.BufferedOutputStream;
-import java.io.ByteArrayInputStream;
-import java.io.ByteArrayOutputStream;
-import java.io.DataInputStream;
-import java.io.DataOutputStream;
-import java.io.File;
-import java.io.FileInputStream;
-import java.io.FileOutputStream;
-import java.io.IOException;
-import java.io.InputStream;
-import java.nio.ByteBuffer;
-import java.nio.file.Files;
-import java.nio.file.Path;
-import java.nio.file.StandardCopyOption;
-import java.util.ArrayList;
-import java.util.Arrays;
-import java.util.List;
-import java.util.concurrent.TimeUnit;
-import javax.annotation.Nullable;
-
-public class LinearRegionFile implements IRegionFile {
-    private static final long SUPERBLOCK = -4323716122432332390L;
-    private static final byte VERSION = 2;
-    private static final int HEADER_SIZE = 32;
-    private static final int FOOTER_SIZE = 8;
-    private static final Logger LOGGER = LogUtils.getLogger();
-    private static final List<Byte> SUPPORTED_VERSIONS = Arrays.asList((byte) 1, (byte) 2);
-    private final byte[][] buffer = new byte[1024][];
-    private final int[] bufferUncompressedSize = new int[1024];
-    private final int[] chunkTimestamps = new int[1024];
-    private final LZ4Compressor compressor;
-    private final LZ4FastDecompressor decompressor;
-    private final int compressionLevel;
-    public boolean closed = false;
-    public Path path;
-    private volatile long lastFlushed = System.nanoTime();
-
-    public LinearRegionFile(Path file, int compression) throws IOException {
-        this.path = file;
-        this.compressionLevel = compression;
-        this.compressor = LZ4Factory.fastestInstance().fastCompressor();
-        this.decompressor = LZ4Factory.fastestInstance().fastDecompressor();
-
-        File regionFile = new File(this.path.toString());
-
-        Arrays.fill(this.bufferUncompressedSize, 0);
-
-        if (!regionFile.canRead()) return;
-
-        try (FileInputStream fileStream = new FileInputStream(regionFile);
-             DataInputStream rawDataStream = new DataInputStream(fileStream)) {
-
-            long superBlock = rawDataStream.readLong();
-            if (superBlock != SUPERBLOCK)
-                throw new RuntimeException("Invalid superblock: " + superBlock + " in " + file);
-
-            byte version = rawDataStream.readByte();
-            if (!SUPPORTED_VERSIONS.contains(version))
-                throw new RuntimeException("Invalid version: " + version + " in " + file);
-
-            rawDataStream.skipBytes(11);
-
-            int dataCount = rawDataStream.readInt();
-            long fileLength = file.toFile().length();
-            if (fileLength != HEADER_SIZE + dataCount + FOOTER_SIZE)
-                throw new IOException("Invalid file length: " + this.path + " " + fileLength + " " + (HEADER_SIZE + dataCount + FOOTER_SIZE));
-
-            rawDataStream.skipBytes(8);
-
-            byte[] rawCompressed = new byte[dataCount];
-            rawDataStream.readFully(rawCompressed, 0, dataCount);
-
-            superBlock = rawDataStream.readLong();
-            if (superBlock != SUPERBLOCK)
-                throw new IOException("Footer superblock invalid " + this.path);
-
-            try (DataInputStream dataStream = new DataInputStream(new ZstdInputStream(new ByteArrayInputStream(rawCompressed)))) {
-
-                int[] starts = new int[1024];
-                for (int i = 0; i < 1024; i++) {
-                    starts[i] = dataStream.readInt();
-                    dataStream.skipBytes(4);
-                }
-
-                for (int i = 0; i < 1024; i++) {
-                    if (starts[i] > 0) {
-                        int size = starts[i];
-                        byte[] b = new byte[size];
-                        dataStream.readFully(b, 0, size);
-
-                        int maxCompressedLength = this.compressor.maxCompressedLength(size);
-                        byte[] compressed = new byte[maxCompressedLength];
-                        int compressedLength = this.compressor.compress(b, 0, size, compressed, 0, maxCompressedLength);
-                        b = new byte[compressedLength];
-                        System.arraycopy(compressed, 0, b, 0, compressedLength);
-
-                        this.buffer[i] = b;
-                        this.bufferUncompressedSize[i] = size;
-                    }
-                }
-            }
-        }
-    }
-
-    private static int getChunkIndex(int x, int z) {
-        return (x & 31) + ((z & 31) << 5);
-    }
-
-    private static int getTimestamp() {
-        return (int) (System.currentTimeMillis() / 1000L);
-    }
-
-    public void flush() throws IOException {
-        flushWrapper();
-    }
-
-    public void flushWrapper() {
-        try {
-            save();
-        } catch (IOException e) {
-            LOGGER.error("Failed to flush region file {}", path.toAbsolutePath(), e);
-        }
-    }
-
-    public boolean doesChunkExist(ChunkPos pos) throws Exception {
-        throw new Exception("doesChunkExist is a stub");
-    }
-
-    private synchronized void save() throws IOException {
-        long timestamp = getTimestamp();
-        short chunkCount = 0;
-
-        File tempFile = new File(path.toString() + ".tmp");
-
-        try (FileOutputStream fileStream = new FileOutputStream(tempFile);
-             ByteArrayOutputStream zstdByteArray = new ByteArrayOutputStream();
-             ZstdOutputStream zstdStream = new ZstdOutputStream(zstdByteArray, this.compressionLevel);
-             DataOutputStream zstdDataStream = new DataOutputStream(zstdStream);
-             DataOutputStream dataStream = new DataOutputStream(fileStream)) {
-
-            dataStream.writeLong(SUPERBLOCK);
-            dataStream.writeByte(VERSION);
-            dataStream.writeLong(timestamp);
-            dataStream.writeByte(this.compressionLevel);
-
-            ArrayList<byte[]> byteBuffers = new ArrayList<>();
-            for (int i = 0; i < 1024; i++) {
-                if (this.bufferUncompressedSize[i] != 0) {
-                    chunkCount += 1;
-                    byte[] content = new byte[bufferUncompressedSize[i]];
-                    this.decompressor.decompress(buffer[i], 0, content, 0, bufferUncompressedSize[i]);
-
-                    byteBuffers.add(content);
-                } else byteBuffers.add(null);
-            }
-            for (int i = 0; i < 1024; i++) {
-                zstdDataStream.writeInt(this.bufferUncompressedSize[i]);
-                zstdDataStream.writeInt(this.chunkTimestamps[i]);
-            }
-            for (int i = 0; i < 1024; i++) {
-                if (byteBuffers.get(i) != null)
-                    zstdDataStream.write(byteBuffers.get(i), 0, byteBuffers.get(i).length);
-            }
-            zstdDataStream.close();
-
-            dataStream.writeShort(chunkCount);
-
-            byte[] compressed = zstdByteArray.toByteArray();
-
-            dataStream.writeInt(compressed.length);
-            dataStream.writeLong(0);
-
-            dataStream.write(compressed, 0, compressed.length);
-            dataStream.writeLong(SUPERBLOCK);
-
-            dataStream.flush();
-            fileStream.getFD().sync();
-            fileStream.getChannel().force(true);
-        }
-        Files.move(tempFile.toPath(), this.path, StandardCopyOption.REPLACE_EXISTING);
-        this.lastFlushed = System.nanoTime();
-    }
-
-    public synchronized void write(ChunkPos pos, ByteBuffer buffer) {
-        try {
-            byte[] b = toByteArray(new ByteArrayInputStream(buffer.array()));
-            int uncompressedSize = b.length;
-
-            int maxCompressedLength = this.compressor.maxCompressedLength(b.length);
-            byte[] compressed = new byte[maxCompressedLength];
-            int compressedLength = this.compressor.compress(b, 0, b.length, compressed, 0, maxCompressedLength);
-            b = new byte[compressedLength];
-            System.arraycopy(compressed, 0, b, 0, compressedLength);
-
-            int index = getChunkIndex(pos.x, pos.z);
-            this.buffer[index] = b;
-            this.chunkTimestamps[index] = getTimestamp();
-            this.bufferUncompressedSize[getChunkIndex(pos.x, pos.z)] = uncompressedSize;
-        } catch (IOException e) {
-            LOGGER.error("Chunk write IOException {} {}", e, this.path);
-        }
-
-        if ((System.nanoTime() - this.lastFlushed) >= TimeUnit.NANOSECONDS.toSeconds(DivineConfig.linearFlushFrequency)) {
-            this.flushWrapper();
-        }
-    }
-
-    public DataOutputStream getChunkDataOutputStream(ChunkPos pos) {
-        return new DataOutputStream(new BufferedOutputStream(new ChunkBuffer(pos)));
-    }
-
-    @Override
-    public MoonriseRegionFileIO.RegionDataController.WriteData moonrise$startWrite(CompoundTag data, ChunkPos pos) {
-        final DataOutputStream out = this.getChunkDataOutputStream(pos);
-
-        return new ca.spottedleaf.moonrise.patches.chunk_system.io.MoonriseRegionFileIO.RegionDataController.WriteData(
-            data, ca.spottedleaf.moonrise.patches.chunk_system.io.MoonriseRegionFileIO.RegionDataController.WriteData.WriteResult.WRITE,
-            out, regionFile -> out.close()
-        );
-    }
-
-    private byte[] toByteArray(InputStream in) throws IOException {
-        ByteArrayOutputStream out = new ByteArrayOutputStream();
-        byte[] tempBuffer = new byte[4096];
-
-        int length;
-        while ((length = in.read(tempBuffer)) >= 0) {
-            out.write(tempBuffer, 0, length);
-        }
-
-        return out.toByteArray();
-    }
-
-    @Nullable
-    public synchronized DataInputStream getChunkDataInputStream(ChunkPos pos) {
-        if (this.bufferUncompressedSize[getChunkIndex(pos.x, pos.z)] != 0) {
-            byte[] content = new byte[bufferUncompressedSize[getChunkIndex(pos.x, pos.z)]];
-            this.decompressor.decompress(this.buffer[getChunkIndex(pos.x, pos.z)], 0, content, 0, bufferUncompressedSize[getChunkIndex(pos.x, pos.z)]);
-            return new DataInputStream(new ByteArrayInputStream(content));
-        }
-        return null;
-    }
-
-    public void clear(ChunkPos pos) {
-        int i = getChunkIndex(pos.x, pos.z);
-        this.buffer[i] = null;
-        this.bufferUncompressedSize[i] = 0;
-        this.chunkTimestamps[i] = getTimestamp();
-        this.flushWrapper();
-    }
-
-    public Path getPath() {
-        return this.path;
-    }
-
-    public boolean hasChunk(ChunkPos pos) {
-        return this.bufferUncompressedSize[getChunkIndex(pos.x, pos.z)] > 0;
-    }
-
-    public void close() throws IOException {
-        if (closed) return;
-        closed = true;
-        flush();
-    }
-
-    public boolean recalculateHeader() {
-        return false;
-    }
-
-    public void setOversized(int x, int z, boolean something) {
-    }
-
-    public CompoundTag getOversizedData(int x, int z) throws IOException {
-        throw new IOException("getOversizedData is a stub " + this.path);
-    }
-
-    public boolean isOversized(int x, int z) {
-        return false;
-    }
-
-    private class ChunkBuffer extends ByteArrayOutputStream {
-        private final ChunkPos pos;
-
-        public ChunkBuffer(ChunkPos chunkcoordintpair) {
-            super();
-            this.pos = chunkcoordintpair;
-        }
-
-        public void close() {
-            ByteBuffer bytebuffer = ByteBuffer.wrap(this.buf, 0, this.count);
-            LinearRegionFile.this.write(this.pos, bytebuffer);
-        }
-    }
-}