Synchronized block entity no longer need polling

Fixes #106

src/main/java/ru/dbotthepony/mc/otm/OverdriveThatMatters.java

@@ -141,7 +141,6 @@ public final class OverdriveThatMatters {
 		EVENT_BUS.addListener(EventPriority.NORMAL, AndroidResearchManager.INSTANCE::syncEvent);
 
 		EVENT_BUS.addListener(EventPriority.NORMAL, SynchronizedBlockEntity.Companion::onServerStopping);
-		EVENT_BUS.addListener(EventPriority.NORMAL, SynchronizedBlockEntity.Companion::onServerStarting);
 		EVENT_BUS.addListener(EventPriority.NORMAL, SynchronizedBlockEntity.Companion::onWatch);
 		EVENT_BUS.addListener(EventPriority.NORMAL, SynchronizedBlockEntity.Companion::onForget);
 		EVENT_BUS.addListener(EventPriority.NORMAL, SynchronizedBlockEntity.Companion::playerDisconnected);

src/main/kotlin/ru/dbotthepony/mc/otm/block/entity/BatteryBankBlockEntity.kt

@@ -301,8 +301,6 @@ class BatteryBankBlockEntity(p_155229_: BlockPos, p_155230_: BlockState) : Matte
 	}
 
 	fun tick() {
-		synchronizeToPlayers()
-
 		if (isBlockedByRedstone)
 			return
 

src/main/kotlin/ru/dbotthepony/mc/otm/block/entity/EnergyCounterBlockEntity.kt

@@ -394,7 +394,6 @@ class EnergyCounterBlockEntity(p_155229_: BlockPos, p_155230_: BlockState) : Mat
 		lastTick = history[historyTick]
 		historyTick = (historyTick + 1) % history.size
 		history[historyTick] = ImpreciseFraction.ZERO
-		synchronizeToPlayers()
 	}
 
 	fun clientTick() {

src/main/kotlin/ru/dbotthepony/mc/otm/block/entity/MatteryWorkerBlockEntity.kt

@@ -353,7 +353,6 @@ abstract class MatteryWorkerBlockEntity<JobType : MatteryWorkerBlockEntity.Job>(
 	fun basicTicker() {
 		batteryChargeLoop()
 		workerLoop()
-		synchronizeToPlayers()
 	}
 
 	companion object {

src/main/kotlin/ru/dbotthepony/mc/otm/block/entity/SynchronizedBlockEntity.kt

@@ -19,6 +19,8 @@ import net.minecraftforge.event.level.ChunkWatchEvent
 import net.minecraftforge.event.server.ServerStartingEvent
 import net.minecraftforge.event.server.ServerStoppingEvent
 import org.apache.logging.log4j.LogManager
+import ru.dbotthepony.mc.otm.NULLABLE_MINECRAFT_SERVER
+import ru.dbotthepony.mc.otm.SERVER_IS_LIVE
 import ru.dbotthepony.mc.otm.core.component1
 import ru.dbotthepony.mc.otm.core.component2
 import ru.dbotthepony.mc.otm.core.component3
@@ -26,12 +28,13 @@ import ru.dbotthepony.mc.otm.core.position
 import ru.dbotthepony.mc.otm.network.BlockEntitySyncPacket
 import ru.dbotthepony.mc.otm.network.FieldSynchronizer
 import ru.dbotthepony.mc.otm.network.WorldNetworkChannel
+import ru.dbotthepony.mc.otm.onceServer
 import java.lang.ref.WeakReference
 import java.util.LinkedList
 import java.util.WeakHashMap
 
 private data class Subscribers(
-	val blockEntities: LinkedList<WeakReference<BlockEntity>> = LinkedList(),
+	val blockEntities: LinkedList<WeakReference<SynchronizedBlockEntity>> = LinkedList(),
 	val players: LinkedList<ServerPlayer> = LinkedList(),
 	val level: WeakReference<Level>,
 	val chunkPos: Long,
@@ -47,18 +50,28 @@ private data class Subscribers(
 		}
 	}
 
-	fun subscribe(blockEntity: BlockEntity) {
-		for (value in blockEntities) {
-			if (value.get() === blockEntity) {
+	fun subscribe(blockEntity: SynchronizedBlockEntity) {
+		val iterator = blockEntities.listIterator()
+
+		for (value in iterator) {
+			val ref = value.get()
+
+			if (ref === blockEntity) {
 				return
+			} else if (ref == null) {
+				iterator.remove()
 			}
 		}
 
 		blockEntities.add(WeakReference(blockEntity))
 		changeset++
+
+		onceServer {
+			blockEntity.synchronizeToPlayers()
+		}
 	}
 
-	fun unsubscribe(blockEntity: BlockEntity): Boolean {
+	fun unsubscribe(blockEntity: SynchronizedBlockEntity): Boolean {
 		val listIterator = blockEntities.listIterator()
 
 		for (value in listIterator) {
@@ -88,18 +101,39 @@ private data class Subscribers(
 }
 
 abstract class SynchronizedBlockEntity(p_155228_: BlockEntityType<*>, p_155229_: BlockPos, p_155230_: BlockState) : BlockEntity(p_155228_, p_155229_, p_155230_) {
-	val synchronizer = FieldSynchronizer()
+	val synchronizer = FieldSynchronizer {
+		if (!isRemoved && level?.isClientSide == false) {
+			onceServer {
+				synchronizeToPlayers(true)
+			}
+		}
+	}
 
 	init {
 		synchronizer.defaultEndpoint.markUnused()
 	}
 
-	open val synchronizationRadius: Double = 32.0
-
 	override fun setLevel(p_155231_: Level) {
 		super.setLevel(p_155231_)
 		unsubscribe()
 		_subCache = null
+
+		if (!p_155231_.isClientSide) {
+			subscribe()
+		}
+	}
+
+	override fun setRemoved() {
+		super.setRemoved()
+		unsubscribe()
+	}
+
+	override fun clearRemoved() {
+		super.clearRemoved()
+
+		if (level?.isClientSide == false) {
+			subscribe()
+		}
 	}
 
 	private var _subCache: Subscribers? = null
@@ -119,6 +153,8 @@ abstract class SynchronizedBlockEntity(p_155228_: BlockEntityType<*>, p_155229_:
 	}
 
 	private fun subscribe(): Subscribers {
+		val level = level
+		check(level is ServerLevel) { "Invalid realm" }
 		unsubscribe()
 		val subs = playerMap.computeIfAbsent(level) { Long2ObjectAVLTreeMap() }.computeIfAbsent(ChunkPos(blockPos).toLong(), Long2ObjectFunction { Subscribers(level = WeakReference(level), chunkPos = ChunkPos(blockPos).toLong()) })
 		subs.subscribe(this)
@@ -130,7 +166,12 @@ abstract class SynchronizedBlockEntity(p_155228_: BlockEntityType<*>, p_155229_:
 	private var lastSubscriptionChangeset = -1
 
 	fun synchronizeToPlayers() {
-		if (synchronizationRadius <= 0.0 || synchronizer.isEmpty) {
+		synchronizeToPlayers(false)
+	}
+
+	protected fun synchronizeToPlayers(callbedBySynchronizer: Boolean) {
+		if (synchronizer.isEmpty || isRemoved) {
+			if (callbedBySynchronizer) synchronizer.markClean()
 			return
 		}
 
@@ -141,35 +182,21 @@ abstract class SynchronizedBlockEntity(p_155228_: BlockEntityType<*>, p_155229_:
 		val subscription = subscription
 
 		if (subscription.players.isEmpty() || lastSubscriptionChangeset == subscription.changeset && !synchronizer.hasChanges) {
+			if (callbedBySynchronizer) synchronizer.markClean()
 			return
 		}
 
 		lastSubscriptionChangeset = subscription.changeset
 
-		val (xi, yi, zi) = blockPos
-		val bx = xi + 0.5
-		val by = yi + 0.5
-		val bz = zi + 0.5
-
-		val double = synchronizationRadius * synchronizationRadius
-
-		subscription.players.stream().filter {
-			if (!it.isAlive) {
-				return@filter false
-			}
-
-			val (x, y, z) = it.position
-
-			(x - bx) * (x - bx) +
-			(y - by) * (y - by) +
-			(z - bz) * (z - bz) <= double
-		}.forEach {
-			val payload = synchronizer.computeEndpointFor(it).collectNetworkPayload()
+		for (player in subscription.players) {
+			val payload = synchronizer.computeEndpointFor(player).collectNetworkPayload()
 
 			if (payload != null) {
-				WorldNetworkChannel.send(it, BlockEntitySyncPacket(blockPos, payload.array, payload.length))
+				WorldNetworkChannel.send(player, BlockEntitySyncPacket(blockPos, payload.array, payload.length))
 			}
 		}
+
+		synchronizer.markClean()
 	}
 
 	/**
@@ -187,16 +214,12 @@ abstract class SynchronizedBlockEntity(p_155228_: BlockEntityType<*>, p_155229_:
 	 * [net.minecraft.server.level.ChunkMap.getPlayers], which is not something we want
 	 */
 	companion object {
-		private val playerMap = WeakHashMap<Level, Long2ObjectAVLTreeMap<Subscribers>>()
+		private val playerMap = WeakHashMap<ServerLevel, Long2ObjectAVLTreeMap<Subscribers>>()
 
 		fun onServerStopping(event: ServerStoppingEvent) {
 			playerMap.clear()
 		}
 
-		fun onServerStarting(event: ServerStartingEvent) {
-			playerMap.clear()
-		}
-
 		fun onWatch(event: ChunkWatchEvent.Watch) {
 			playerMap.computeIfAbsent(event.level) { Long2ObjectAVLTreeMap() }.computeIfAbsent(event.pos.toLong(), Long2ObjectFunction { Subscribers(level = WeakReference(event.level), chunkPos = event.pos.toLong()) }).let {
 				val (blocks, players) = it
@@ -204,6 +227,22 @@ abstract class SynchronizedBlockEntity(p_155228_: BlockEntityType<*>, p_155229_:
 				if (event.player !in players) {
 					players.add(event.player)
 					it.changeset++
+
+					onceServer(20) {
+						if (!event.player.hasDisconnected()) {
+							val iterator = blocks.listIterator()
+
+							for (block in iterator) {
+								val deref = block.get()
+
+								if (deref == null) {
+									iterator.remove()
+								} else {
+									deref.synchronizeToPlayers(false)
+								}
+							}
+						}
+					}
 				}
 			}
 		}
@@ -216,6 +255,18 @@ abstract class SynchronizedBlockEntity(p_155228_: BlockEntityType<*>, p_155229_:
 					playerMap.get(event.level)?.remove(event.pos.toLong())
 				} else {
 					subs.changeset++
+
+					val iterator = subs.blockEntities.listIterator()
+
+					for (block in iterator) {
+						val deref = block.get()
+
+						if (deref == null) {
+							iterator.remove()
+						} else {
+							deref.synchronizer.removeEndpointFor(event.player)
+						}
+					}
 				}
 			}
 		}

src/main/kotlin/ru/dbotthepony/mc/otm/block/entity/blackhole/BlackHoleBlockEntity.kt

@@ -167,8 +167,6 @@ class BlackHoleBlockEntity(p_155229_: BlockPos, p_155230_: BlockState) : Synchro
 		nbt["spin_direction"] = spinDirection
 	}
 
-	override val synchronizationRadius: Double = 256.0
-
 	override fun load(tag: CompoundTag) {
 		super.load(tag)
 		mass = tag.mapIf("mass", ImpreciseFraction::deserializeNBT) ?: BASELINE_MASS
@@ -223,8 +221,6 @@ class BlackHoleBlockEntity(p_155229_: BlockPos, p_155230_: BlockState) : Synchro
 	}
 
 	fun tick() {
-		synchronizeToPlayers()
-
 		sleepTicks--
 		if (sleepTicks > 0) return
 		val level = level as? ServerLevel ?: return

src/main/kotlin/ru/dbotthepony/mc/otm/block/matter/MatterCapacitorBankBlock.kt

@@ -27,14 +27,6 @@ class MatterCapacitorBankBlock : RotatableMatteryBlock(), EntityBlock {
 		return MatterCapacitorBankBlockEntity(blockPos, blockState)
 	}
 
-	override fun <T : BlockEntity> getTicker(
-		p_153212_: Level,
-		p_153213_: BlockState,
-		p_153214_: BlockEntityType<T>
-	): BlockEntityTicker<T>? {
-		return SynchronizedBlockEntity::synchronizeToPlayers.blockServerTicker(p_153212_, MBlockEntities.MATTER_CAPACITOR_BANK, p_153214_)
-	}
-
 	override fun getStateForPlacement(context: BlockPlaceContext): BlockState? {
 		var state = super.getStateForPlacement(context) ?: return null
 

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

@@ -69,7 +69,10 @@ enum class MapAction {
 	CLEAR, ADD, REMOVE
 }
 
-class FieldSynchronizer {
+class FieldSynchronizer(private val callback: Runnable, private val alwaysCallCallback: Boolean) {
+	constructor() : this(Runnable {}, false)
+	constructor(callback: Runnable) : this(callback, false)
+
 	private val fields = ArrayList<IField<*>>()
 	private val observers = LinkedList<IField<*>>()
 
@@ -77,7 +80,23 @@ class FieldSynchronizer {
 	val isNotEmpty: Boolean get() = fields.isNotEmpty()
 
 	var hasChanges: Boolean = false
-		private set
+		private set(value) {
+			if (value != field) {
+				field = value
+
+				if (value && !alwaysCallCallback) {
+					callback.run()
+				}
+			}
+
+			if (alwaysCallCallback && value) {
+				callback.run()
+			}
+		}
+
+	fun markClean() {
+		hasChanges = false
+	}
 
 	fun byte(
 		value: Byte = 0,
@@ -345,6 +364,10 @@ class FieldSynchronizer {
 		return boundEndpoints.computeIfAbsent(obj) { Endpoint() }
 	}
 
+	fun removeEndpointFor(obj: Any): Endpoint? {
+		return boundEndpoints.remove(obj)
+	}
+
 	fun endpointFor(obj: Any): Endpoint? {
 		return boundEndpoints[obj]
 	}
@@ -820,8 +843,11 @@ class FieldSynchronizer {
 	 * [defaultEndpoint]#collectNetworkPayload
 	 */
 	fun collectNetworkPayload(): FastByteArrayOutputStream? {
+		check(!defaultEndpoint.unused) { "Default endpoint is not used" }
 		observe()
-		return defaultEndpoint.collectNetworkPayload()
+		val values = defaultEndpoint.collectNetworkPayload()
+		markClean()
+		return values
 	}
 
 	fun applyNetworkPayload(stream: DataInputStream): Int {