Send remainder of partially-inserted stacks back to source

src/main/java/net/shadowfacts/phycon/api/PacketSource.java

@@ -0,0 +1,15 @@
+package net.shadowfacts.phycon.api;
+
+import net.shadowfacts.phycon.api.packet.Packet;
+
+/**
+ * @author shadowfacts
+ */
+public interface PacketSource {
+	// todo: better name for this
+	void sendToSingle(Packet packet);
+
+	void sendToAll(Packet packet);
+
+	void sendToAll(Packet packet, Iterable<PacketSink> destinations);
+}

src/main/kotlin/net/shadowfacts/phycon/network/DeviceBlockEntity.kt

@@ -4,18 +4,16 @@ import net.minecraft.block.BlockState
 import net.minecraft.block.entity.BlockEntity
 import net.minecraft.block.entity.BlockEntityType
 import net.minecraft.nbt.CompoundTag
-import net.minecraft.util.Tickable
 import net.shadowfacts.phycon.api.PacketSink
+import net.shadowfacts.phycon.api.PacketSource
 import net.shadowfacts.phycon.api.packet.Packet
 import net.shadowfacts.phycon.api.util.MACAddress
 import net.shadowfacts.phycon.network.packet.DeviceRemovedPacket
-import java.lang.ref.WeakReference
-import java.util.*
 
 /**
  * @author shadowfacts
  */
-abstract class DeviceBlockEntity(type: BlockEntityType<*>): BlockEntity(type), PacketSink {
+abstract class DeviceBlockEntity(type: BlockEntityType<*>): BlockEntity(type), PacketSink, PacketSource {
 
 	var macAddress = MACAddress.random()
 		protected set
@@ -48,8 +46,7 @@ abstract class DeviceBlockEntity(type: BlockEntityType<*>): BlockEntity(type), P
 		destination.handle(packet)
 	}
 
-	// todo: better name for this
-	fun sendToSingle(packet: Packet) {
+	override fun sendToSingle(packet: Packet) {
 		val destinations = NetworkUtil.findDestinations(world!!, pos)
 		if (destinations.size != 1) {
 			// todo: handle this better
@@ -59,11 +56,11 @@ abstract class DeviceBlockEntity(type: BlockEntityType<*>): BlockEntity(type), P
 		send(packet, destinations.first())
 	}
 
-	fun sendToAll(packet: Packet) {
+	override fun sendToAll(packet: Packet) {
 		sendToAll(packet, NetworkUtil.findDestinations(world!!, pos))
 	}
 
-	fun sendToAll(packet: Packet, destinations: Iterable<PacketSink>) {
+	override fun sendToAll(packet: Packet, destinations: Iterable<PacketSink>) {
 		destinations.forEach {
 			it.handle(packet)
 		}

src/main/kotlin/net/shadowfacts/phycon/network/block/netinterface/InterfaceBlockEntity.kt

@@ -4,17 +4,19 @@ import alexiil.mc.lib.attributes.SearchOptions
 import alexiil.mc.lib.attributes.Simulation
 import alexiil.mc.lib.attributes.item.GroupedItemInv
 import alexiil.mc.lib.attributes.item.ItemAttributes
-import net.minecraft.entity.ItemEntity
+import net.minecraft.item.ItemStack
 import net.minecraft.util.math.Direction
 import net.shadowfacts.phycon.api.packet.Packet
 import net.shadowfacts.phycon.init.PhyBlockEntities
 import net.shadowfacts.phycon.network.DeviceBlockEntity
+import net.shadowfacts.phycon.network.component.ItemStackPacketHandler
+import net.shadowfacts.phycon.network.component.handleItemStack
 import net.shadowfacts.phycon.network.packet.*
 
 /**
  * @author shadowfacts
  */
-class InterfaceBlockEntity: DeviceBlockEntity(PhyBlockEntities.INTERFACE) {
+class InterfaceBlockEntity: DeviceBlockEntity(PhyBlockEntities.INTERFACE), ItemStackPacketHandler {
 
 	private val facing: Direction
 		get() = world!!.getBlockState(pos)[InterfaceBlock.FACING]
@@ -73,21 +75,14 @@ class InterfaceBlockEntity: DeviceBlockEntity(PhyBlockEntities.INTERFACE) {
 		}
 	}
 
-	private fun handleItemStack(packet: ItemStackPacket) {
+	override fun doHandleItemStack(packet: ItemStackPacket): ItemStack {
 		val inventory = getInventory()
 		if (inventory != null) {
 			val remaining = inventory.insert(packet.stack)
-			if (!remaining.isEmpty) {
-				// todo: should this send whatever was left back to the terminal instead of dropping it?
-				// todo: calculate entity spawn point by finding non-obstructed location
-				val entity = ItemEntity(world!!, pos.x.toDouble(), pos.y + 1.0, pos.z.toDouble(), remaining)
-				world!!.spawnEntity(entity)
-			}
+			// whatever could not be inserted will be sent back to the packet's source
+			return remaining
 		} else {
-			// todo: should the stack back to the terminal instead of dropping it?
-			// todo: calculate entity spawn point by finding non-obstructed location
-			val entity = ItemEntity(world!!, pos.x.toDouble(), pos.y + 1.0, pos.z.toDouble(), packet.stack)
-			world!!.spawnEntity(entity)
+			return packet.stack
 		}
 	}
 

src/main/kotlin/net/shadowfacts/phycon/network/block/terminal/TerminalBlockEntity.kt

@@ -7,7 +7,6 @@ import it.unimi.dsi.fastutil.ints.Int2ObjectArrayMap
 import net.fabricmc.fabric.api.block.entity.BlockEntityClientSerializable
 import net.fabricmc.fabric.api.screenhandler.v1.ExtendedScreenHandlerFactory
 import net.minecraft.block.BlockState
-import net.minecraft.entity.ItemEntity
 import net.minecraft.entity.player.PlayerEntity
 import net.minecraft.entity.player.PlayerInventory
 import net.minecraft.inventory.Inventory
@@ -25,16 +24,16 @@ import net.shadowfacts.phycon.api.util.MACAddress
 import net.shadowfacts.phycon.init.PhyBlockEntities
 import net.shadowfacts.phycon.network.DeviceBlockEntity
 import net.shadowfacts.phycon.network.block.netinterface.InterfaceBlockEntity
+import net.shadowfacts.phycon.network.component.ItemStackPacketHandler
+import net.shadowfacts.phycon.network.component.handleItemStack
 import net.shadowfacts.phycon.network.packet.*
-import net.shadowfacts.phycon.util.fromTag
-import net.shadowfacts.phycon.util.toTag
 import java.util.*
 import kotlin.math.min
 
 /**
  * @author shadowfacts
  */
-class TerminalBlockEntity: DeviceBlockEntity(PhyBlockEntities.TERMINAL), InventoryChangedListener, BlockEntityClientSerializable, Tickable {
+class TerminalBlockEntity: DeviceBlockEntity(PhyBlockEntities.TERMINAL), InventoryChangedListener, BlockEntityClientSerializable, Tickable, ItemStackPacketHandler {
 
 	companion object {
 		val LOCATE_REQUEST_TIMEOUT = 40 // ticks
@@ -44,6 +43,7 @@ class TerminalBlockEntity: DeviceBlockEntity(PhyBlockEntities.TERMINAL), Invento
 	private val inventoryCache = mutableMapOf<MACAddress, GroupedItemInv>()
 	val internalBuffer = TerminalBufferInventory(18)
 
+	private val locateRequestQueue = LinkedList<StackLocateRequest>()
 	private val pendingRequests = LinkedList<StackLocateRequest>()
     private val pendingInsertions = Int2ObjectArrayMap<PendingStackInsertion>()
 
@@ -85,24 +85,20 @@ class TerminalBlockEntity: DeviceBlockEntity(PhyBlockEntities.TERMINAL), Invento
 		if (request != null) {
 			request.results.add(packet.amount to packet.sourceInterface)
 			if (request.totalResultAmount >= request.amount || counter - request.timestamp >= LOCATE_REQUEST_TIMEOUT || request.results.size >= inventoryCache.size) {
-				pendingRequests.remove(request)
 				stackLocateRequestCompleted(request)
 			}
 		}
 	}
 
-	private fun handleItemStack(packet: ItemStackPacket) {
+	override fun doHandleItemStack(packet: ItemStackPacket): ItemStack {
 		val remaining = internalBuffer.insertFromNetwork(packet.stack)
-		if (!remaining.isEmpty) {
-			// todo: calculate entity spawn point by finding non-obstructed location
-			val entity = ItemEntity(world!!, pos.x.toDouble(), pos.y + 1.0, pos.z.toDouble(), remaining)
-			world!!.spawnEntity(entity)
-		}
 
 		// this happens outside the normal update loop because by receiving the item stack packet
 		// we "know" how much the count in the source inventory has changed
 		updateNetItems()
 		sync()
+
+		return remaining
 	}
 
 	private fun handleCapacity(packet: CapacityPacket) {
@@ -111,9 +107,8 @@ class TerminalBlockEntity: DeviceBlockEntity(PhyBlockEntities.TERMINAL), Invento
 		}
 		if (insertion != null) {
 			insertion.results.add(packet.capacity to packet.receivingInterface)
-			if (insertion.totalCapacity >= insertion.stack.count || counter - insertion.timestamp >= INSERTION_TIMEOUT || insertion.results.size >= inventoryCache.size) {
-				pendingInsertions.remove(insertion.bufferSlot)
-				completeInsertion(insertion)
+			if (insertion.isFinishable(counter)) {
+				finishInsertion(insertion)
 			}
 		}
 	}
@@ -146,6 +141,35 @@ class TerminalBlockEntity: DeviceBlockEntity(PhyBlockEntities.TERMINAL), Invento
 		}
 	}
 
+	private fun finishPendingInsertions() {
+		if (world!!.isClient) return
+
+		for (insertion in pendingInsertions.values) {
+			if (!insertion.isFinishable(counter)) continue
+			finishInsertion(insertion)
+		}
+	}
+
+	private fun sendEnqueuedLocateRequests() {
+		if (world!!.isClient) return
+
+		for (request in locateRequestQueue) {
+			pendingRequests.add(request)
+			sendToSingle(LocateStackPacket(request.stack, macAddress))
+		}
+		locateRequestQueue.clear()
+	}
+
+	private fun finishPendingRequests() {
+		if (world!!.isClient) return
+
+		for (request in pendingRequests) {
+			if (request.isFinishable(counter)) {
+				stackLocateRequestCompleted(request)
+			}
+		}
+	}
+
 	fun addObserver() {
 		observers++
 	}
@@ -155,12 +179,15 @@ class TerminalBlockEntity: DeviceBlockEntity(PhyBlockEntities.TERMINAL), Invento
 	}
 
 	override fun tick() {
-		if (observers > 0 && (++counter % 20) == 0) {
+		if (observers > 0 && (++counter % 10) == 0) {
 			if (world!!.isClient) {
 				println(cachedNetItems)
 			} else {
 				updateNetItems()
+				sendEnqueuedLocateRequests()
+				finishPendingRequests()
                 beginInsertions()
+				finishPendingInsertions()
 				sync()
 			}
 		}
@@ -190,11 +217,12 @@ class TerminalBlockEntity: DeviceBlockEntity(PhyBlockEntities.TERMINAL), Invento
 	}
 
 	fun requestItem(stack: ItemStack, amount: Int = stack.count) {
-		pendingRequests.add(StackLocateRequest(stack, amount, counter))
-		sendToSingle(LocateStackPacket(stack, macAddress))
+		locateRequestQueue.add(StackLocateRequest(stack, amount, counter))
 	}
 
 	private fun stackLocateRequestCompleted(request: StackLocateRequest) {
+		pendingRequests.remove(request)
+
 		// todo: also sort results by interface priority
 		val sortedResults = request.results.sortedByDescending { it.first }.toMutableList()
 		var amountRequested = 0
@@ -206,7 +234,9 @@ class TerminalBlockEntity: DeviceBlockEntity(PhyBlockEntities.TERMINAL), Invento
 		}
 	}
 
-	private fun completeInsertion(insertion: PendingStackInsertion) {
+	private fun finishInsertion(insertion: PendingStackInsertion) {
+		pendingInsertions.remove(insertion.bufferSlot)
+
 		// todo: also sort results by interface priority
 		val sortedResults = insertion.results.sortedBy { it.first }.toMutableList()
 		val remaining = insertion.stack
@@ -279,6 +309,10 @@ data class StackLocateRequest(
 ) {
 	val totalResultAmount: Int
 		get() = results.fold(0) { acc, (amount, _) -> acc + amount }
+
+	fun isFinishable(currentTimestamp: Int): Boolean {
+		return totalResultAmount > amount || currentTimestamp - timestamp >= TerminalBlockEntity.LOCATE_REQUEST_TIMEOUT
+	}
 }
 
 data class PendingStackInsertion(
@@ -289,4 +323,8 @@ data class PendingStackInsertion(
 ) {
 	val totalCapacity: Int
 		get() = results.fold(0) { acc, (amount, _) -> acc + amount }
+
+	fun isFinishable(currentTimestamp: Int): Boolean {
+		return totalCapacity > stack.count || currentTimestamp - timestamp >= TerminalBlockEntity.INSERTION_TIMEOUT
+	}
 }

src/main/kotlin/net/shadowfacts/phycon/network/component/ItemStackPacketHandler.kt

@@ -0,0 +1,31 @@
+package net.shadowfacts.phycon.network.component
+
+import net.minecraft.block.entity.BlockEntity
+import net.minecraft.entity.ItemEntity
+import net.minecraft.item.ItemStack
+import net.shadowfacts.phycon.api.PacketSink
+import net.shadowfacts.phycon.api.PacketSource
+import net.shadowfacts.phycon.network.packet.ItemStackPacket
+
+/**
+ * @author shadowfacts
+ */
+interface ItemStackPacketHandler: PacketSink, PacketSource {
+	fun doHandleItemStack(packet: ItemStackPacket): ItemStack
+}
+
+fun <BE> BE.handleItemStack(packet: ItemStackPacket) where BE: BlockEntity, BE: ItemStackPacketHandler {
+	// todo: is 5 a good number?
+	// the max bounce count should always be odd, so the item is spawned in-world at the
+	if (packet.bounceCount == 5) {
+		// todo: calculate entity spawn point by finding non-obstructed location
+		val entity = ItemEntity(world!!, pos.x.toDouble(), pos.y + 1.0, pos.z.toDouble(), packet.stack)
+		world!!.spawnEntity(entity)
+		return
+	}
+	val remainder = doHandleItemStack(packet)
+	// if there are any items remaining, send them back to the source with incremented bounce count
+	if (!remainder.isEmpty) {
+		sendToSingle(ItemStackPacket(remainder, packet.bounceCount + 1, macAddress, packet.source))
+	}
+}

src/main/kotlin/net/shadowfacts/phycon/network/packet/ItemStackPacket.kt

@@ -6,5 +6,6 @@ import net.shadowfacts.phycon.api.util.MACAddress
 /**
  * @author shadowfacts
  */
-class ItemStackPacket(val stack: ItemStack, source: MACAddress, destination: MACAddress): BasePacket(source, destination) {
+class ItemStackPacket(val stack: ItemStack, val bounceCount: Int, source: MACAddress, destination: MACAddress): BasePacket(source, destination) {
+	constructor(stack: ItemStack, source: MACAddress, destination: MACAddress): this(stack, 0, source, destination)
 }