From 44647d1228b674022a46c3359155bcd551500b32 Mon Sep 17 00:00:00 2001
From: DBotThePony <dbotthepony@yandex.ru>
Date: Wed, 30 Nov 2022 20:23:55 +0700
Subject: [PATCH] forValidRefs extension function

---
 .../block/entity/SynchronizedBlockEntity.kt   | 54 +++++--------------
 .../kotlin/ru/dbotthepony/mc/otm/core/Ext.kt  | 18 +++++++
 2 files changed, 31 insertions(+), 41 deletions(-)

diff --git a/src/main/kotlin/ru/dbotthepony/mc/otm/block/entity/SynchronizedBlockEntity.kt b/src/main/kotlin/ru/dbotthepony/mc/otm/block/entity/SynchronizedBlockEntity.kt
index 6b5088e5a..8ff9ad739 100644
--- a/src/main/kotlin/ru/dbotthepony/mc/otm/block/entity/SynchronizedBlockEntity.kt
+++ b/src/main/kotlin/ru/dbotthepony/mc/otm/block/entity/SynchronizedBlockEntity.kt
@@ -16,6 +16,7 @@ import net.minecraftforge.event.entity.player.PlayerEvent
 import net.minecraftforge.event.level.ChunkWatchEvent
 import net.minecraftforge.event.level.LevelEvent
 import net.minecraftforge.event.server.ServerStoppingEvent
+import ru.dbotthepony.mc.otm.core.forValidRefs
 import ru.dbotthepony.mc.otm.network.BlockEntitySyncPacket
 import ru.dbotthepony.mc.otm.network.FieldSynchronizer
 import ru.dbotthepony.mc.otm.network.WorldNetworkChannel
@@ -304,18 +305,11 @@ abstract class SynchronizedBlockEntity(p_155228_: BlockEntityType<*>, p_155229_:
 						listIterator.remove()
 					} else if (ref.players.isNotEmpty()) {
 						var hitObservers = false
-						val blockIterator = ref.observingBlockEntities.listIterator()
 
-						for (bvalue in blockIterator) {
-							val bref = bvalue.get()
-
-							if (bref == null) {
-								blockIterator.remove()
-							} else {
-								hitObservers = true
-								hitAnyObservers = true
-								bref.synchronizeToPlayers()
-							}
+						ref.observingBlockEntities.forValidRefs {
+							hitObservers = true
+							hitAnyObservers = true
+							it.synchronizeToPlayers()
 						}
 
 						if (!hitObservers) {
@@ -340,16 +334,8 @@ abstract class SynchronizedBlockEntity(p_155228_: BlockEntityType<*>, p_155229_:
 
 					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)
-								}
+							blocks.forValidRefs {
+								it.synchronizeToPlayers(false)
 							}
 						}
 					}
@@ -365,17 +351,8 @@ 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)
-						}
+					subs.blockEntities.forValidRefs {
+						it.synchronizer.removeEndpointFor(event.player)
 					}
 				}
 			}
@@ -386,18 +363,13 @@ abstract class SynchronizedBlockEntity(p_155228_: BlockEntityType<*>, p_155229_:
 				val iterator = tree.iterator()
 
 				for (entry in iterator) {
-					val listIterator = entry.value.players.listIterator()
+					if (entry.value.players.remove(event.entity)) {
+						entry.value.changeset++
 
-					for (value in listIterator) {
-						if (value === event.entity) {
-							listIterator.remove()
-							entry.value.changeset++
+						if (entry.value.isEmpty) {
+							iterator.remove()
 						}
 					}
-
-					if (entry.value.isEmpty) {
-						iterator.remove()
-					}
 				}
 			}
 		}
diff --git a/src/main/kotlin/ru/dbotthepony/mc/otm/core/Ext.kt b/src/main/kotlin/ru/dbotthepony/mc/otm/core/Ext.kt
index 614b49645..5466189c0 100644
--- a/src/main/kotlin/ru/dbotthepony/mc/otm/core/Ext.kt
+++ b/src/main/kotlin/ru/dbotthepony/mc/otm/core/Ext.kt
@@ -28,6 +28,8 @@ import net.minecraftforge.items.IItemHandler
 import net.minecraftforge.registries.ForgeRegistries
 import net.minecraftforge.registries.ForgeRegistry
 import net.minecraftforge.registries.IForgeRegistry
+import java.lang.ref.Reference
+import java.lang.ref.WeakReference
 import java.math.BigInteger
 import java.util.Arrays
 import java.util.Spliterators
@@ -421,10 +423,26 @@ fun <T> Collection<T>.probablyParallelStream(): Stream<out T> {
 
 fun <T> Array<T>.stream(): Stream<T> = Arrays.stream(this)
 
+@Suppress("unchecked_cast")
 fun <T> Stream<T?>.filterNotNull(): Stream<T> {
 	return filter { it != null } as Stream<T>
 }
 
+@Suppress("unchecked_cast")
 inline fun <reified T> Stream<*>.filterIsInstance(): Stream<T> {
 	return filter { it is T } as Stream<T>
 }
+
+inline fun <T> MutableList<out Reference<out T>>.forValidRefs(fn: (T) -> Unit) {
+	val iterator = listIterator()
+
+	for (value in iterator) {
+		val get = value.get()
+
+		if (get == null) {
+			iterator.remove()
+		} else {
+			fn.invoke(get)
+		}
+	}
+}