For the love of god

src/main/kotlin/ru/dbotthepony/mc/otm/network/WorldNetworkChannel.kt

@@ -1,14 +1,20 @@
 package ru.dbotthepony.mc.otm.network
 
 import it.unimi.dsi.fastutil.io.FastByteArrayInputStream
+import it.unimi.dsi.fastutil.objects.Object2ObjectFunction
+import it.unimi.dsi.fastutil.objects.Object2ObjectOpenHashMap
 import net.minecraft.core.BlockPos
 import net.minecraft.network.FriendlyByteBuf
+import net.minecraft.world.level.Level
 import net.minecraftforge.network.NetworkDirection
 import net.minecraftforge.network.NetworkEvent
 import org.apache.logging.log4j.LogManager
 import ru.dbotthepony.mc.otm.android.feature.ItemEntityDataPacket
 import ru.dbotthepony.mc.otm.block.entity.MatteryBlockEntity
 import ru.dbotthepony.mc.otm.client.minecraft
+import ru.dbotthepony.mc.otm.client.onceClient
+import java.lang.ref.SoftReference
+import java.util.WeakHashMap
 import java.util.function.Supplier
 
 class BlockEntitySyncPacket(val position: BlockPos, val buffer: ByteArray, val validBytes: Int) : MatteryPacket {
@@ -17,23 +23,63 @@ class BlockEntitySyncPacket(val position: BlockPos, val buffer: ByteArray, val v
 		buff.writeBytes(buffer, 0, validBytes)
 	}
 
+	private fun execute() {
+		val level = minecraft.player?.level
+
+		if (level == null) {
+			LOGGER.error("Received BlockEntitySyncPacket before we are in valid level.")
+
+			onceClient {
+				execute()
+			}
+
+			return
+		}
+
+		val blockEntity = level.getBlockEntity(position)
+
+		if (blockEntity == null) {
+			LOGGER.warn("Putting BlockEntitySyncPacket received for $position into backlog because there is literally no block entity there!")
+			LOGGER.warn("This is CERTAINLY a bug in one of optimizing mods you have or server has installed!")
+			LOGGER.warn("This can cause memory leak.")
+
+			backlog.computeIfAbsent(level) { Object2ObjectOpenHashMap() }
+				.computeIfAbsent(position, Object2ObjectFunction { ArrayList() })
+				.add(this)
+
+			return
+		} else if (blockEntity !is MatteryBlockEntity) {
+			LOGGER.warn("Dropping BlockEntitySyncPacket received for $position, because there is $blockEntity which is not MatteryBlockEntity!")
+			backlog[level]?.remove(position)
+			return
+		}
+
+		val packets = backlog[level]?.remove(position)
+
+		try {
+			if (packets != null) {
+				for (packet in packets) {
+					blockEntity.synchronizer.read(FastByteArrayInputStream(packet.buffer, 0, packet.validBytes))
+				}
+			}
+
+			blockEntity.synchronizer.read(FastByteArrayInputStream(buffer, 0, validBytes))
+		} catch(err: Throwable) {
+			LOGGER.error("Exception while reading synchronized BlockEntity data!\nPosition: $position\nBlock: ${level.getBlockState(position)}\nBlock entity: $blockEntity", err)
+		}
+	}
+
 	override fun play(context: Supplier<NetworkEvent.Context>) {
 		context.packetHandled = true
 
 		context.enqueueWork {
-			val level = minecraft.player?.level ?: return@enqueueWork
+			execute()
-			val blockEntity = level.getBlockEntity(position) as? MatteryBlockEntity ?: return@enqueueWork
-
-			try {
-				blockEntity.synchronizer.read(FastByteArrayInputStream(buffer, 0, validBytes))
-			} catch(err: Throwable) {
-				LOGGER.error("Exception while reading synchronized BlockEntity data!\nPosition: $position\nBlock: ${level.getBlockState(position)}\nBlock entity: $blockEntity", err)
-				throw err
-			}
 		}
 	}
 
 	companion object {
+		private val backlog = WeakHashMap<Level, Object2ObjectOpenHashMap<BlockPos, ArrayList<BlockEntitySyncPacket>>>()
+
 		fun read(buff: FriendlyByteBuf): BlockEntitySyncPacket {
 			val position = buff.readBlockPos()
 			val size = buff.readableBytes()
@@ -47,7 +93,7 @@ class BlockEntitySyncPacket(val position: BlockPos, val buffer: ByteArray, val v
 }
 
 object WorldNetworkChannel : MatteryNetworkChannel(
-	version = "2",
+	version = "3",
 	name = "world"
 ) {
 	fun register() {