Merge branch 'fastutil' into AE2-Omnifactory

remove unsupported removal call

src/api/java/appeng/api/storage/data/IAEItemStack.java

@@ -112,4 +112,13 @@ public interface IAEItemStack extends IAEStack<IAEItemStack>
 	 * @return definition stack
 	 */
 	ItemStack getDefinition();
+
+	/**
+	 * Compare this AE item stack to another item stack, but ignores
+	 * the amount. It checks the item type, NBT and damage values.
+	 *
+	 * @param is An item stack
+	 */
+	boolean equals(ItemStack is);
+
 }

src/main/java/appeng/container/implementations/ContainerCraftingCPU.java

@@ -159,56 +159,58 @@ public class ContainerCraftingCPU extends AEBaseContainer implements IMEMonitorH
 	@Override
 	public void detectAndSendChanges()
 	{
-		if( Platform.isServer() && this.getMonitor() != null && !this.list.isEmpty() )
+		if( Platform.isServer() && this.getMonitor() != null )
 		{
-			try
+			if( this.getEstimatedTime() >= 0 )
 			{
-				if( this.getEstimatedTime() >= 0 )
+				final long elapsedTime = this.getMonitor().getElapsedTime();
+				final double remainingItems = this.getMonitor().getRemainingItemCount();
+				final double startItems = this.getMonitor().getStartItemCount();
+				final long eta = (long) ( elapsedTime / Math.max( 1d, ( startItems - remainingItems ) ) * remainingItems );
+				this.setEstimatedTime( eta );
+			}
+			if( !this.list.isEmpty() )
+			{
+				try
 				{
-					final long elapsedTime = this.getMonitor().getElapsedTime();
-					final double remainingItems = this.getMonitor().getRemainingItemCount();
-					final double startItems = this.getMonitor().getStartItemCount();
-					final long eta = (long) ( elapsedTime / Math.max( 1d, ( startItems - remainingItems ) ) * remainingItems );
-					this.setEstimatedTime( eta );
-				}
+					final PacketMEInventoryUpdate a = new PacketMEInventoryUpdate( (byte) 0 );
+					final PacketMEInventoryUpdate b = new PacketMEInventoryUpdate( (byte) 1 );
+					final PacketMEInventoryUpdate c = new PacketMEInventoryUpdate( (byte) 2 );
 
-				final PacketMEInventoryUpdate a = new PacketMEInventoryUpdate( (byte) 0 );
-				final PacketMEInventoryUpdate b = new PacketMEInventoryUpdate( (byte) 1 );
-				final PacketMEInventoryUpdate c = new PacketMEInventoryUpdate( (byte) 2 );
-
-				for( final IAEItemStack out : this.list )
-				{
-					a.appendItem( this.getMonitor().getItemStack( out, CraftingItemList.STORAGE ) );
-					b.appendItem( this.getMonitor().getItemStack( out, CraftingItemList.ACTIVE ) );
-					c.appendItem( this.getMonitor().getItemStack( out, CraftingItemList.PENDING ) );
-				}
-
-				this.list.resetStatus();
-
-				for( final Object g : this.listeners )
-				{
-					if( g instanceof EntityPlayer )
+					for( final IAEItemStack out : this.list )
 					{
-						if( !a.isEmpty() )
-						{
-							NetworkHandler.instance().sendTo( a, (EntityPlayerMP) g );
-						}
+						a.appendItem( this.getMonitor().getItemStack( out, CraftingItemList.STORAGE ) );
+						b.appendItem( this.getMonitor().getItemStack( out, CraftingItemList.ACTIVE ) );
+						c.appendItem( this.getMonitor().getItemStack( out, CraftingItemList.PENDING ) );
+					}
 
-						if( !b.isEmpty() )
-						{
-							NetworkHandler.instance().sendTo( b, (EntityPlayerMP) g );
-						}
+					this.list.resetStatus();
 
-						if( !c.isEmpty() )
+					for( final Object g : this.listeners )
+					{
+						if( g instanceof EntityPlayer )
 						{
-							NetworkHandler.instance().sendTo( c, (EntityPlayerMP) g );
+							if( !a.isEmpty() )
+							{
+								NetworkHandler.instance().sendTo( a, (EntityPlayerMP) g );
+							}
+
+							if( !b.isEmpty() )
+							{
+								NetworkHandler.instance().sendTo( b, (EntityPlayerMP) g );
+							}
+
+							if( !c.isEmpty() )
+							{
+								NetworkHandler.instance().sendTo( c, (EntityPlayerMP) g );
+							}
 						}
 					}
 				}
-			}
-			catch( final IOException e )
-			{
-				// :P
+				catch( final IOException e )
+				{
+					// :P
+				}
 			}
 		}
 		super.detectAndSendChanges();

src/main/java/appeng/container/implementations/ContainerPatternTerm.java

@@ -134,14 +134,16 @@ public class ContainerPatternTerm extends ContainerMEMonitorable implements IAEA
 		{
 			return ItemStack.EMPTY;
 		}
-
-		final AppEngSlot clickSlot = ( AppEngSlot ) this.inventorySlots.get( idx ); // require AE SLots!
-		ItemStack itemStack = clickSlot.getStack();
-		if( AEApi.instance().definitions().materials().blankPattern().isSameAs( itemStack ) )
+		if( this.inventorySlots.get( idx ) instanceof SlotPlayerInv || this.inventorySlots.get( idx ) instanceof SlotPlayerHotBar )
 		{
-			IItemHandler patternInv = this.getPatternTerminal().getInventoryByName( "pattern" );
-			ItemStack remainder = patternInv.insertItem( 0, itemStack, false );
-			clickSlot.putStack( remainder );
+			final AppEngSlot clickSlot = ( AppEngSlot ) this.inventorySlots.get( idx ); // require AE SLots!
+			ItemStack itemStack = clickSlot.getStack();
+			if( AEApi.instance().definitions().materials().blankPattern().isSameAs( itemStack ) )
+			{
+				IItemHandler patternInv = this.getPatternTerminal().getInventoryByName( "pattern" );
+				ItemStack remainder = patternInv.insertItem( 0, itemStack, false );
+				clickSlot.putStack( remainder );
+			}
 		}
 		return super.transferStackInSlot( p, idx );
 	}

src/main/java/appeng/crafting/MECraftingInventory.java

@@ -28,7 +28,9 @@ import appeng.api.storage.IStorageChannel;
 import appeng.api.storage.channels.IItemStorageChannel;
 import appeng.api.storage.data.IAEItemStack;
 import appeng.api.storage.data.IItemList;
+import appeng.me.helpers.PlayerSource;
 import appeng.util.inv.ItemListIgnoreCrafting;
+import net.minecraft.util.text.TextComponentString;
 
 
 public class MECraftingInventory implements IMEInventory<IAEItemStack>
@@ -307,8 +309,15 @@ public class MECraftingInventory implements IMEInventory<IAEItemStack>
 
 				if( result == null || result.getStackSize() != extra.getStackSize() )
 				{
+					if( src.player().isPresent() )
+					{
+						if( result == null )
+							src.player().get().sendStatusMessage( new TextComponentString( "System reported " + extra.getStackSize() + " " + extra.getDefinition().getDisplayName() + " available but could not extract anything" ), false );
+						else
+							src.player().get().sendStatusMessage( new TextComponentString( "System reported " + extra.getStackSize() + " " + extra.getDefinition().getDisplayName() + " available but could only extract " + result.getStackSize() ), false );
+					}
 					failed = true;
-					break;
+					if( !src.player().isPresent() ) break;
 				}
 			}
 		}

src/main/java/appeng/me/GridNode.java

@@ -633,10 +633,10 @@ public class GridNode implements IGridNode, IPathItem
 			this.usedChannels = 0;
 		}
 
-		final int idx = this.connections.indexOf( fast );
+		final int idx = this.connections.indexOf( (IGridConnection) fast );
 		if( idx > 0 )
 		{
-			this.connections.remove( fast );
+			this.connections.remove( (IGridConnection) fast );
 			this.connections.add( 0, (IGridConnection) fast );
 		}
 	}

src/main/java/appeng/me/cache/CraftingGridCache.java

@@ -42,6 +42,10 @@ import com.google.common.collect.ImmutableList;
 import com.google.common.collect.ImmutableSet;
 import com.google.common.collect.Multimap;
 
+import it.unimi.dsi.fastutil.objects.Object2ObjectMap;
+import it.unimi.dsi.fastutil.objects.Object2ObjectOpenHashMap;
+import it.unimi.dsi.fastutil.objects.ObjectRBTreeSet;
+import it.unimi.dsi.fastutil.objects.ObjectSet;
 import net.minecraft.world.World;
 
 import appeng.api.AEApi;
@@ -105,8 +109,8 @@ public class CraftingGridCache implements ICraftingGrid, ICraftingProviderHelper
 	private final Set<ICraftingProvider> craftingProviders = new HashSet<>();
 	private final Map<IGridNode, ICraftingWatcher> craftingWatchers = new HashMap<>();
 	private final IGrid grid;
-	private final Map<ICraftingPatternDetails, List<ICraftingMedium>> craftingMethods = new HashMap<>();
-	private final Map<IAEItemStack, ImmutableList<ICraftingPatternDetails>> craftableItems = new HashMap<>();
+	private final Object2ObjectMap<ICraftingPatternDetails, List<ICraftingMedium>> craftingMethods = new Object2ObjectOpenHashMap<>();
+	private final Object2ObjectMap<IAEItemStack, ImmutableList<ICraftingPatternDetails>> craftableItems = new Object2ObjectOpenHashMap<>();
 	private final Set<IAEItemStack> emitableItems = new HashSet<>();
 	private final Map<String, CraftingLinkNexus> craftingLinks = new HashMap<>();
 	private final Multimap<IAEStack, CraftingWatcher> interests = HashMultimap.create();
@@ -160,11 +164,11 @@ public class CraftingGridCache implements ICraftingGrid, ICraftingProviderHelper
 	{
 		if( machine instanceof ICraftingWatcherHost )
 		{
-			final ICraftingWatcher craftingWatcher = this.craftingWatchers.get( machine );
+			final ICraftingWatcher craftingWatcher = this.craftingWatchers.get( gridNode );
 			if( craftingWatcher != null )
 			{
 				craftingWatcher.reset();
-				this.craftingWatchers.remove( machine );
+				this.craftingWatchers.remove( gridNode );
 			}
 		}
 
@@ -270,7 +274,7 @@ public class CraftingGridCache implements ICraftingGrid, ICraftingProviderHelper
 			return;
 		}
 
-		final Map<IAEItemStack, ImmutableList<ICraftingPatternDetails>> oldItems = this.craftableItems;
+		final Object2ObjectMap<IAEItemStack, ImmutableList<ICraftingPatternDetails>> oldItems = this.craftableItems;
 
 		// erase list.
 		this.craftingMethods.clear();
@@ -287,7 +291,7 @@ public class CraftingGridCache implements ICraftingGrid, ICraftingProviderHelper
 			provider.provideCrafting( this );
 		}
 
-		final Map<IAEItemStack, Set<ICraftingPatternDetails>> tmpCraft = new HashMap<>();
+		final Object2ObjectMap<IAEItemStack, ObjectSet<ICraftingPatternDetails>> tmpCraft = new Object2ObjectOpenHashMap<>();
 
 		// new craftables!
 		for( final ICraftingPatternDetails details : this.craftingMethods.keySet() )
@@ -298,11 +302,11 @@ public class CraftingGridCache implements ICraftingGrid, ICraftingProviderHelper
 				out.reset();
 				out.setCraftable( true );
 
-				Set<ICraftingPatternDetails> methods = tmpCraft.get( out );
+				ObjectSet<ICraftingPatternDetails> methods = tmpCraft.get( out );
 
 				if( methods == null )
 				{
-					tmpCraft.put( out, methods = new TreeSet<>( COMPARATOR ) );
+					tmpCraft.put( out, methods = new ObjectRBTreeSet<>( COMPARATOR ) );
 				}
 
 				methods.add( details );
@@ -310,7 +314,7 @@ public class CraftingGridCache implements ICraftingGrid, ICraftingProviderHelper
 		}
 
 		// make them immutable
-		for( final Entry<IAEItemStack, Set<ICraftingPatternDetails>> e : tmpCraft.entrySet() )
+		for( final Entry<IAEItemStack, ObjectSet<ICraftingPatternDetails>> e : tmpCraft.entrySet() )
 		{
 			this.craftableItems.put( e.getKey(), ImmutableList.copyOf( e.getValue() ) );
 		}
@@ -635,7 +639,11 @@ public class CraftingGridCache implements ICraftingGrid, ICraftingProviderHelper
 
 	public boolean hasCpu( final ICraftingCPU cpu )
 	{
-		return this.craftingCPUClusters.contains( cpu );
+		if (cpu instanceof CraftingCPUCluster)
+		{
+			return this.craftingCPUClusters.contains( (CraftingCPUCluster) cpu );
+		}
+		return false;
 	}
 
 	public GenericInterestManager<CraftingWatcher> getInterestManager()

src/main/java/appeng/me/cache/EnergyGridCache.java

@@ -30,6 +30,7 @@ import java.util.PriorityQueue;
 import java.util.Queue;
 import java.util.Set;
 
+import com.google.common.base.Preconditions;
 import com.google.common.collect.HashMultiset;
 import com.google.common.collect.Multiset;
 import com.google.common.collect.Sets;
@@ -63,7 +64,7 @@ import appeng.me.energy.EnergyWatcher;
 public class EnergyGridCache implements IEnergyGrid
 {
 
-	private static final double MAX_BUFFER_STORAGE = 200;
+	private static final double MAX_BUFFER_STORAGE = 800;
 	private static final Comparator<IEnergyGridProvider> COMPARATOR_HIGHEST_AMOUNT_STORED_FIRST = ( o1, o2 ) -> Double.compare( o2.getProviderStoredEnergy(),
 			o1.getProviderStoredEnergy() );
 
@@ -76,9 +77,24 @@ public class EnergyGridCache implements IEnergyGrid
 	};
 
 	private final NavigableSet<EnergyThreshold> interests = Sets.newTreeSet();
+
+	// Should only be modified from the add/remove methods below to guard against
+	// concurrent modifications
 	private final double averageLength = 40.0;
 	private final Set<IAEPowerStorage> providers = new LinkedHashSet<>();
+	// Used to track whether an extraction is currently in progress, to fail fast
+	// when something externally
+	// modifies the energy grid.
+	private boolean ongoingExtractOperation = false;
+
+	// Should only be modified from the add/remove methods below to guard against
+	// concurrent modifications
 	private final Set<IAEPowerStorage> requesters = new LinkedHashSet<>();
+	// Used to track whether an injection is currently in progress, to fail fast
+	// when something externally
+	// modifies the energy grid.
+	private boolean ongoingInjectOperation = false;
+
 	private final Multiset<IEnergyGridProvider> energyGridProviders = HashMultiset.create();
 	private final IGrid myGrid;
 	private final HashMap<IGridNode, IEnergyWatcher> watchers = new HashMap<>();
@@ -110,6 +126,10 @@ public class EnergyGridCache implements IEnergyGrid
 	private double lastStoredPower = -1;
 
 	private final GridPowerStorage localStorage = new GridPowerStorage();
+	private Set<IAEPowerStorage> providerToRemove = new HashSet<>();
+	private Set<IAEPowerStorage> requesterToRemove = new HashSet<>();
+	private Set<IAEPowerStorage> providersToAdd = new HashSet<>();
+	private Set<IAEPowerStorage> requesterToAdd = new HashSet<>();
 
 	public EnergyGridCache( final IGrid g )
 	{
@@ -143,18 +163,32 @@ public class EnergyGridCache implements IEnergyGrid
 	{
 		if( ev.storage.isAEPublicPowerStorage() )
 		{
-			switch( ev.type )
+			switch ( ev.type )
 			{
 				case PROVIDE_POWER:
 					if( ev.storage.getPowerFlow() != AccessRestriction.WRITE )
 					{
-						this.providers.add( ev.storage );
+						if( !ongoingExtractOperation )
+						{
+							addProvider( ev.storage );
+						}
+						else
+						{
+							this.providersToAdd.add( ev.storage );
+						}
 					}
 					break;
 				case REQUEST_POWER:
 					if( ev.storage.getPowerFlow() != AccessRestriction.READ )
 					{
-						this.requesters.add( ev.storage );
+						if( !ongoingInjectOperation )
+						{
+							addRequester( ev.storage );
+						}
+						else
+						{
+							this.requesterToAdd.add( ev.storage );
+						}
 					}
 					break;
 			}
@@ -168,6 +202,23 @@ public class EnergyGridCache implements IEnergyGrid
 	@Override
 	public void onUpdateTick()
 	{
+		if (!providerToRemove.isEmpty() && !ongoingExtractOperation) {
+			this.providers.removeIf( p -> providerToRemove.contains( p ) );
+			providerToRemove.clear();
+		}
+		if (!requesterToRemove.isEmpty() && !ongoingInjectOperation) {
+			this.requesters.removeIf( r -> providerToRemove.contains( r ) );
+			requesterToRemove.clear();
+		}
+		if (!providersToAdd.isEmpty() && !ongoingExtractOperation) {
+			this.providers.addAll(providersToAdd);
+			providersToAdd.clear();
+		}
+		if( !requesterToAdd.isEmpty() && !ongoingInjectOperation){
+			this.requesters.addAll(requesterToAdd);
+			requesterToAdd.clear();
+		}
+
 		if( !this.interests.isEmpty() )
 		{
 			final double oldPower = this.lastStoredPower;
@@ -303,18 +354,30 @@ public class EnergyGridCache implements IEnergyGrid
 
 		final Iterator<IAEPowerStorage> it = this.providers.iterator();
 
-		while( extractedPower < amt && it.hasNext() )
+		ongoingExtractOperation = true;
+		try
 		{
-			final IAEPowerStorage node = it.next();
-
-			final double req = amt - extractedPower;
-			final double newPower = node.extractAEPower( req, mode, PowerMultiplier.ONE );
-			extractedPower += newPower;
-
-			if( newPower < req && mode == Actionable.MODULATE )
+			while ( extractedPower < amt && it.hasNext() )
 			{
-				it.remove();
+				final IAEPowerStorage node = it.next();
+
+				if ( providerToRemove.contains( node )) {
+					it.remove();
+					providerToRemove.remove( node );
+					continue;
+				}
+
+				final double req = amt - extractedPower;
+				final double newPower = node.extractAEPower( req, mode, PowerMultiplier.ONE );
+				extractedPower += newPower;
+
+				if( newPower < req && mode == Actionable.MODULATE )
+				{
+					it.remove();
+				}
 			}
+		} finally {
+			ongoingExtractOperation = false;
 		}
 
 		final double result = Math.min( extractedPower, amt );
@@ -340,15 +403,29 @@ public class EnergyGridCache implements IEnergyGrid
 
 		final Iterator<IAEPowerStorage> it = this.requesters.iterator();
 
-		while( amt > 0 && it.hasNext() )
+		ongoingInjectOperation = true;
+		try
 		{
-			final IAEPowerStorage node = it.next();
-			amt = node.injectAEPower( amt, mode );
-
-			if( amt > 0 && mode == Actionable.MODULATE )
+			while ( amt > 0 && it.hasNext() )
 			{
-				it.remove();
+				final IAEPowerStorage node = it.next();
+
+				if ( requesterToRemove.contains( node )) {
+					it.remove();
+					requesterToRemove.remove( node );
+					continue;
+				}
+
+				amt = node.injectAEPower( amt, mode );
+
+				if( amt > 0 && mode == Actionable.MODULATE )
+				{
+					it.remove();
+				}
 			}
+		} finally
+		{
+			ongoingInjectOperation = false;
 		}
 
 		final double overflow = Math.max( 0.0, amt );
@@ -505,9 +582,22 @@ public class EnergyGridCache implements IEnergyGrid
 					this.globalMaxPower -= ps.getAEMaxPower();
 					this.globalAvailablePower -= ps.getAECurrentPower();
 				}
-
-				this.providers.remove( ps );
-				this.requesters.remove( ps );
+				if( !ongoingExtractOperation )
+				{
+					removeProvider( ps );
+				}
+				else
+				{
+					this.providerToRemove.add( ps );
+				}
+				if( !ongoingInjectOperation )
+				{
+					removeRequester( ps );
+				}
+				else
+				{
+					this.requesterToRemove.add( ps );
+				}
 			}
 		}
 
@@ -523,6 +613,31 @@ public class EnergyGridCache implements IEnergyGrid
 		}
 	}
 
+	private void addRequester(IAEPowerStorage requester) {
+		Preconditions.checkState(!ongoingInjectOperation,
+				"Cannot modify energy requesters while energy is being injected.");
+		this.requesters.add(requester);
+	}
+
+	private void removeRequester(IAEPowerStorage requester) {
+		Preconditions.checkState(!ongoingInjectOperation,
+				"Cannot modify energy requesters while energy is being injected.");
+		this.requesters.remove(requester);
+	}
+
+	private void addProvider(IAEPowerStorage provider) {
+		Preconditions.checkState(!ongoingExtractOperation,
+				"Cannot modify energy providers while energy is being extracted.");
+		this.providers.add(provider);
+	}
+
+	private void removeProvider(IAEPowerStorage provider) {
+		Preconditions.checkState(!ongoingExtractOperation,
+				"Cannot modify energy providers while energy is being extracted.");
+		this.providers.remove(provider);
+	}
+
+
 	@Override
 	public void addNode( final IGridNode node, final IGridHost machine )
 	{
@@ -554,12 +669,26 @@ public class EnergyGridCache implements IEnergyGrid
 				if( current > 0 && ps.getPowerFlow() != AccessRestriction.WRITE )
 				{
 					this.globalAvailablePower += current;
-					this.providers.add( ps );
+					if( !ongoingExtractOperation )
+					{
+						addProvider( ps );
+					}
+					else
+					{
+						this.providersToAdd.add( ps );
+					}
 				}
 
 				if( current < max && ps.getPowerFlow() != AccessRestriction.READ )
 				{
-					this.requesters.add( ps );
+					if( !ongoingInjectOperation )
+					{
+						addRequester( ps );
+					}
+					else
+					{
+						this.requesterToAdd.add( ps );
+					}
 				}
 			}
 		}

src/main/java/appeng/me/cache/GridStorageCache.java

@@ -101,12 +101,12 @@ public class GridStorageCache implements IStorageGrid
 
 		if( machine instanceof IStackWatcherHost )
 		{
-			final IStackWatcher myWatcher = this.watchers.get( machine );
+			final IStackWatcher myWatcher = this.watchers.get( node );
 
 			if( myWatcher != null )
 			{
 				myWatcher.reset();
-				this.watchers.remove( machine );
+				this.watchers.remove( node );
 			}
 		}
 	}

src/main/java/appeng/me/cache/PathGridCache.java

@@ -314,7 +314,7 @@ public class PathGridCache implements IPathingGrid
 		int depth = 0;
 		for( final IGridNode nodes : this.requireChannels )
 		{
-			if( !this.semiOpen.contains( nodes ) )
+			if( !this.semiOpen.contains( (IPathItem) nodes ) )
 			{
 				final IGridBlock gb = nodes.getGridBlock();
 				final EnumSet<GridFlags> flags = gb.getFlags();

src/main/java/appeng/me/cluster/implementations/CraftingCPUCluster.java

@@ -23,6 +23,7 @@ import java.util.*;
 import java.util.Map.Entry;
 import java.util.stream.Collectors;
 
+import com.google.common.base.Preconditions;
 import com.google.common.collect.ImmutableList;
 
 import net.minecraft.inventory.InventoryCrafting;
@@ -233,8 +234,9 @@ public final class CraftingCPUCluster implements IAECluster, ICraftingCPU
 
 	public IAEItemStack injectItems( final IAEItemStack input, final Actionable type, final IActionSource src )
 	{
-		if( !( input instanceof IAEItemStack ) )
-		{
+		// also stop accepting items when the job is complete, i.e. to prevent re-insertion when pushing out
+		// items during storeItems
+		if (input == null || isComplete) {
 			return input;
 		}
 
@@ -292,7 +294,7 @@ public final class CraftingCPUCluster implements IAECluster, ICraftingCPU
 				{
 					is.decStackSize( what.getStackSize() );
 
-					this.updateElapsedTime( what );
+					this.updateRemainingItemCount( what );
 					this.markDirty();
 					this.postCraftingStatusChange( what.copy().setStackSize( -what.getStackSize() ) );
 
@@ -431,6 +433,11 @@ public final class CraftingCPUCluster implements IAECluster, ICraftingCPU
 			AELog.crafting( LOG_MARK_AS_COMPLETE, logStack );
 		}
 
+		// Waiting for can potentially contain items at this point, if the user has a 64xplank->64xbutton processing
+		// recipe for example, but only requested 1xbutton. We just ignore the rest since it will be dumped
+		// back into the network inventory regardless. For this to work it's important that injectItems in this CPU
+		// does not accept any further items if isComplete is true.
+		this.waitingFor.resetStatus();
 		this.remainingItemCount = 0;
 		this.startItemCount = 0;
 		this.lastTime = 0;
@@ -828,6 +835,7 @@ public final class CraftingCPUCluster implements IAECluster, ICraftingCPU
 
 	private void storeItems()
 	{
+		Preconditions.checkState(isComplete, "CPU should be complete to prevent re-insertion when dumping items");
 		final IGrid g = this.getGrid();
 
 		if( g == null )
@@ -838,23 +846,24 @@ public final class CraftingCPUCluster implements IAECluster, ICraftingCPU
 		final IStorageGrid sg = g.getCache( IStorageGrid.class );
 		final IMEInventory<IAEItemStack> ii = sg.getInventory( AEApi.instance().storage().getStorageChannel( IItemStorageChannel.class ) );
 
-		for( IAEItemStack is : this.inventory.getItemList() )
+		IItemList<IAEItemStack> itemList = this.inventory.getItemList();
+		for( IAEItemStack is : itemList )
 		{
-			is = this.inventory.extractItems( is.copy(), Actionable.MODULATE, this.machineSrc );
+			this.postChange( is, this.machineSrc );
+			IAEItemStack remainder = ii.injectItems( is.copy(), Actionable.MODULATE, this.machineSrc );
 
-			if( is != null )
+			// The network was unable to receive all of the items, i.e. no or not enough storage space left
+			if( remainder != null )
 			{
-				this.postChange( is, this.machineSrc );
-				is = ii.injectItems( is, Actionable.MODULATE, this.machineSrc );
+				is.setStackSize( remainder.getStackSize() );
 			}
-
-			if( is != null )
+			else
 			{
-				this.inventory.injectItems( is, Actionable.MODULATE, this.machineSrc );
+				is.reset();
 			}
 		}
 
-		if( this.inventory.getItemList().isEmpty() )
+		if( itemList.isEmpty() )
 		{
 			this.inventory = new MECraftingInventory();
 		}
@@ -939,14 +948,13 @@ public final class CraftingCPUCluster implements IAECluster, ICraftingCPU
 	@Override
 	public boolean isBusy()
 	{
-		final Iterator<Entry<ICraftingPatternDetails, TaskProgress>> i = this.tasks.entrySet().iterator();
 
-		while( i.hasNext() )
+		this.tasks.entrySet().removeIf(
+				taskProgressEntry -> taskProgressEntry.getValue().value <= 0 );
+
+		if( !this.waitingFor.isEmpty() || !this.tasks.isEmpty() )
 		{
-			if( i.next().getValue().value <= 0 )
-			{
-				i.remove();
-			}
+			this.updateElapsedTime();
 		}
 
 		return !this.tasks.isEmpty() || !this.waitingFor.isEmpty();
@@ -1338,12 +1346,16 @@ public final class CraftingCPUCluster implements IAECluster, ICraftingCPU
 		this.remainingItemCount = itemCount;
 	}
 
-	private void updateElapsedTime( final IAEItemStack is )
+	private void updateRemainingItemCount( final IAEItemStack is )
+	{
+		this.remainingItemCount = this.getRemainingItemCount() - is.getStackSize();
+	}
+
+	private void updateElapsedTime()
 	{
 		final long nextStartTime = System.nanoTime();
 		this.elapsedTime = this.getElapsedTime() + nextStartTime - this.lastTime;
 		this.lastTime = nextStartTime;
-		this.remainingItemCount = this.getRemainingItemCount() - is.getStackSize();
 	}
 
 	public long getElapsedTime()

src/main/java/appeng/me/storage/BasicCellInventory.java

@@ -277,6 +277,7 @@ public class BasicCellInventory<T extends IAEStack<T>> extends AbstractCellInven
 		}
 
 		t.setStackSize( stackSize );
+		t.setCraftable( false );
 
 		if( stackSize > 0 )
 		{

src/main/java/appeng/parts/misc/ItemHandlerAdapter.java

@@ -19,17 +19,10 @@
 package appeng.parts.misc;
 
 
-import java.util.*;
-
-import appeng.api.config.Settings;
-import appeng.api.config.StorageFilter;
-import it.unimi.dsi.fastutil.objects.Object2ObjectMap;
-import it.unimi.dsi.fastutil.objects.Object2ObjectOpenHashMap;
-import net.minecraft.item.ItemStack;
-import net.minecraftforge.items.IItemHandler;
-
 import appeng.api.AEApi;
 import appeng.api.config.Actionable;
+import appeng.api.config.Settings;
+import appeng.api.config.StorageFilter;
 import appeng.api.networking.security.IActionSource;
 import appeng.api.networking.storage.IBaseMonitor;
 import appeng.api.networking.ticking.TickRateModulation;
@@ -39,12 +32,24 @@ import appeng.api.storage.channels.IItemStorageChannel;
 import appeng.api.storage.data.IAEItemStack;
 import appeng.api.storage.data.IItemList;
 import appeng.core.AELog;
+import appeng.me.GridAccessException;
 import appeng.me.helpers.IGridProxyable;
 import appeng.me.storage.ITickingMonitor;
 import appeng.util.Platform;
+import appeng.util.inv.ItemHandlerIterator;
+import appeng.util.inv.ItemSlot;
 import appeng.util.item.AEItemStack;
+import it.unimi.dsi.fastutil.objects.Object2ObjectMap;
+import it.unimi.dsi.fastutil.objects.Object2ObjectOpenHashMap;
+import net.minecraft.item.ItemStack;
+import net.minecraftforge.items.IItemHandler;
 import org.apache.commons.lang3.tuple.Pair;
 
+import java.util.ArrayList;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
+
 
 /**
  * Wraps an Item Handler in such a way that it can be used as an IMEInventory for items.
@@ -79,22 +84,15 @@ class ItemHandlerAdapter implements IMEInventory<IAEItemStack>, IBaseMonitor<IAE
 
 		int slotCount = this.itemHandler.getSlots();
 		boolean simulate = ( type == Actionable.SIMULATE );
-		List<Pair<Integer, Integer>> injectedList = new ArrayList<>();
+
 		// This uses a brute force approach and tries to jam it in every slot the inventory exposes.
 		for( int i = 0; i < slotCount && !remaining.isEmpty(); i++ )
 		{
-			int countPre = remaining.getCount();
 			remaining = this.itemHandler.insertItem( i, remaining, simulate );
-			int countPos = remaining.getCount();
 			if( remaining.isEmpty() )
 			{
-				injectedList.add( Pair.of( i, countPre ) );
 				break;
 			}
-			else if( countPos < countPre )
-			{
-				injectedList.add( Pair.of( i, countPre - countPos ) );
-			}
 		}
 
 		// At this point, we still have some items left...
@@ -106,28 +104,13 @@ class ItemHandlerAdapter implements IMEInventory<IAEItemStack>, IBaseMonitor<IAE
 
 		if( type == Actionable.MODULATE )
 		{
-			if( this.cache.cachedAeStacks.length == 0 )
+			try
 			{
-				this.cache.update();
+				this.proxyable.getProxy().getTick().alertDevice( this.proxyable.getProxy().getNode() );
 			}
-			else
+			catch( GridAccessException ex )
 			{
-				for( Pair<Integer, Integer> pair : injectedList )
-				{
-					if( pair.getKey() >= this.cache.cachedAeStacks.length )
-					{
-						this.cache.update();
-						break;
-					}
-					if( this.cache.cachedAeStacks[pair.getKey()] == null )
-					{
-						this.cache.cachedAeStacks[pair.getKey()] = iox.copy().setStackSize( pair.getValue() );
-					}
-					else
-					{
-						this.cache.cachedAeStacks[pair.getKey()].incStackSize( pair.getValue() );
-					}
-				}
+				// meh
 			}
 
 		}
@@ -145,10 +128,8 @@ class ItemHandlerAdapter implements IMEInventory<IAEItemStack>, IBaseMonitor<IAE
 		ItemStack gathered = ItemStack.EMPTY;
 
 		final boolean simulate = ( mode == Actionable.SIMULATE );
-		List<Pair<Integer, Integer>> extractedList = new ArrayList<>();
 
-
-		for ( int i = 0; i < this.itemHandler.getSlots(); i++ )
+		for( int i = 0; i < this.itemHandler.getSlots(); i++ )
 		{
 			ItemStack stackInInventorySlot = this.itemHandler.getStackInSlot( i );
 
@@ -191,16 +172,10 @@ class ItemHandlerAdapter implements IMEInventory<IAEItemStack>, IBaseMonitor<IAE
 					}
 					remainingCurrentSlot -= extracted.getCount();
 				}
-			}
-			while ( !extracted.isEmpty() && remainingCurrentSlot > 0 );
+			} while ( !extracted.isEmpty() && remainingCurrentSlot > 0 );
 
 			remainingSize -= stackSizeCurrentSlot - remainingCurrentSlot;
 
-			if (!gathered.isEmpty())
-			{
-				extractedList.add( Pair.of( i, gathered.getCount() ) );
-			}
-
 			// Done?
 			if( remainingSize <= 0 )
 			{
@@ -212,23 +187,13 @@ class ItemHandlerAdapter implements IMEInventory<IAEItemStack>, IBaseMonitor<IAE
 		{
 			if( mode == Actionable.MODULATE )
 			{
-				if( this.cache.cachedAeStacks.length == 0 )
+				try
 				{
-					this.cache.update();
+					this.proxyable.getProxy().getTick().alertDevice( this.proxyable.getProxy().getNode() );
 				}
-				else
+				catch( GridAccessException ex )
 				{
-					for( Pair<Integer, Integer> pair : extractedList )
-					{
-						if( this.cache.cachedAeStacks[pair.getKey()] != null )
-						{
-							this.cache.cachedAeStacks[pair.getKey()].decStackSize( pair.getValue() );
-							if( this.cache.cachedAeStacks[pair.getKey()].getStackSize() == 0 )
-							{
-								this.cache.cachedAeStacks[pair.getKey()] = null;
-							}
-						}
-					}
+					// meh
 				}
 			}
 
@@ -286,7 +251,7 @@ class ItemHandlerAdapter implements IMEInventory<IAEItemStack>, IBaseMonitor<IAE
 	private void postDifference( Iterable<IAEItemStack> a )
 	{
 		final Iterator<Map.Entry<IMEMonitorHandlerReceiver<IAEItemStack>, Object>> i = this.listeners.entrySet().iterator();
-		while( i.hasNext() )
+		while ( i.hasNext() )
 		{
 			final Map.Entry<IMEMonitorHandlerReceiver<IAEItemStack>, Object> l = i.next();
 			final IMEMonitorHandlerReceiver<IAEItemStack> key = l.getKey();
@@ -301,9 +266,9 @@ class ItemHandlerAdapter implements IMEInventory<IAEItemStack>, IBaseMonitor<IAE
 		}
 	}
 
-	private static class InventoryCache
+	private static class InventoryCache implements Iterable<ItemSlot>
 	{
-		private IAEItemStack[] cachedAeStacks = new IAEItemStack[0];
+		private IItemList<IAEItemStack> cachedAeStacks = AEApi.instance().storage().getStorageChannel( IItemStorageChannel.class ).createList();
 		private final IItemHandler itemHandler;
 		private final StorageFilter mode;
 
@@ -315,106 +280,77 @@ class ItemHandlerAdapter implements IMEInventory<IAEItemStack>, IBaseMonitor<IAE
 
 		public IItemList<IAEItemStack> getAvailableItems( IItemList<IAEItemStack> out )
 		{
-			Arrays.stream( this.cachedAeStacks ).forEach( out::add );
+			this.cachedAeStacks.forEach( out::add );
 			return out;
 		}
 
+		private StorageFilter getMode()
+		{
+			return this.mode;
+		}
+
 		public List<IAEItemStack> update()
 		{
 			final List<IAEItemStack> changes = new ArrayList<>();
-			final int slots = this.itemHandler.getSlots();
 
-			// Make room for new slots
-			if( slots > this.cachedAeStacks.length )
+			IItemList<IAEItemStack> storage = AEApi.instance().storage().getStorageChannel( IItemStorageChannel.class ).createList();
+
+			for( final ItemSlot is : this )
 			{
-				this.cachedAeStacks = Arrays.copyOf( this.cachedAeStacks, slots );
+				final ItemStack stackInSlot = !is.isExtractable() && this.getMode() == StorageFilter.EXTRACTABLE_ONLY ? ItemStack.EMPTY : is.getItemStack();
+				if( !stackInSlot.isEmpty() )
+				{
+					storage.add( AEItemStack.fromItemStack( stackInSlot ) );
+				}
 			}
 
-			for( int slot = 0; slot < slots; slot++ )
+			Iterator<IAEItemStack> cachedAeStacksIterator = cachedAeStacks.iterator();
+			while ( cachedAeStacksIterator.hasNext() )
 			{
-				// Save the old stuff
-				final IAEItemStack oldAeIS = this.cachedAeStacks[slot];
-				ItemStack newIS = this.itemHandler.getStackInSlot( slot );
-				if( this.mode == StorageFilter.EXTRACTABLE_ONLY && !newIS.isEmpty() )
+				IAEItemStack cachedStack = cachedAeStacksIterator.next();
+				IAEItemStack storedStack = storage.findPrecise( cachedStack );
+				if( storedStack == null )
 				{
-					if( this.itemHandler.extractItem( slot, 1, true ).isEmpty() )
-					{
-						newIS = ItemStack.EMPTY;
-					}
+					changes.add( cachedStack.setStackSize( -cachedStack.getStackSize() ) );
+				}
+				else if( cachedStack.getStackSize() != storedStack.getStackSize() )
+				{
+					handleStackSizeChanged( cachedStack, storedStack, changes );
 				}
-				this.handlePossibleSlotChanges( slot, oldAeIS, newIS, changes );
 			}
 
-			// Handle cases where the number of slots actually is lower now than before
-			if( slots < this.cachedAeStacks.length )
+			for( IAEItemStack storedStack : storage )
 			{
-				for( int slot = slots; slot < this.cachedAeStacks.length; slot++ )
+				if( cachedAeStacks.findPrecise( storedStack ) == null )
 				{
-					final IAEItemStack aeStack = this.cachedAeStacks[slot];
-
-					if( aeStack != null )
-					{
-						final IAEItemStack a = aeStack.copy();
-						a.setStackSize( -a.getStackSize() );
-						changes.add( a );
-					}
+					cachedAeStacks.add( storedStack );
+					changes.add( storedStack.copy() );
 				}
-
-				// Reduce the cache size
-				this.cachedAeStacks = Arrays.copyOf( this.cachedAeStacks, slots );
 			}
 
 			return changes;
 		}
 
-		private void handlePossibleSlotChanges( int slot, IAEItemStack oldAeIS, ItemStack newIS, List<IAEItemStack> changes )
-		{
-			if( oldAeIS != null && oldAeIS.isSameType( newIS ) )
-			{
-				this.handleStackSizeChanged( slot, oldAeIS, newIS, changes );
-			}
-			else
-			{
-				this.handleItemChanged( slot, oldAeIS, newIS, changes );
-			}
-		}
-
-		private void handleStackSizeChanged( int slot, IAEItemStack oldAeIS, ItemStack newIS, List<IAEItemStack> changes )
+		private void handleStackSizeChanged( IAEItemStack cachedStack, IAEItemStack storedStack, List<IAEItemStack> changes )
 		{
 			// Still the same item, but amount might have changed
-			final long diff = newIS.getCount() - oldAeIS.getStackSize();
+			final long diff = storedStack.getStackSize() - cachedStack.getStackSize();
 
 			if( diff != 0 )
 			{
-				final IAEItemStack stack = oldAeIS.copy();
-				stack.setStackSize( newIS.getCount() );
+				cachedStack.setStackSize( storedStack.getStackSize() );
 
-				this.cachedAeStacks[slot] = stack;
-
-				final IAEItemStack a = stack.copy();
-				a.setStackSize( diff );
-				changes.add( a );
+				final IAEItemStack diffStack = cachedStack.copy();
+				diffStack.setStackSize( diff );
+				changes.add( diffStack );
 			}
 		}
 
-		private void handleItemChanged( int slot, IAEItemStack oldAeIS, ItemStack newIS, List<IAEItemStack> changes )
+		@Override
+		public Iterator<ItemSlot> iterator()
 		{
-			// Completely different item
-			this.cachedAeStacks[slot] = AEItemStack.fromItemStack( newIS );
-
-			// If we had a stack previously in this slot, notify the network about its disappearance
-			if( oldAeIS != null )
-			{
-				oldAeIS.setStackSize( -oldAeIS.getStackSize() );
-				changes.add( oldAeIS );
-			}
-
-			// Notify the network about the new stack. Note that this is null if newIS was null
-			if( this.cachedAeStacks[slot] != null )
-			{
-				changes.add( this.cachedAeStacks[slot] );
-			}
+			return new ItemHandlerIterator( this.itemHandler );
 		}
-	}
 
+	}
 }

src/main/java/appeng/parts/misc/ItemRepositoryAdapter.java

@@ -1,16 +1,5 @@
 package appeng.parts.misc;
 
-import java.util.*;
-import java.util.stream.Collectors;
-
-import appeng.api.storage.IStorageChannel;
-
-import appeng.core.AELog;
-import com.jaquadro.minecraft.storagedrawers.api.capabilities.IItemRepository;
-import it.unimi.dsi.fastutil.objects.Object2ObjectMap;
-import it.unimi.dsi.fastutil.objects.Object2ObjectOpenHashMap;
-import net.minecraft.item.ItemStack;
-
 import appeng.api.AEApi;
 import appeng.api.config.Actionable;
 import appeng.api.networking.security.IActionSource;
@@ -18,15 +7,24 @@ import appeng.api.networking.storage.IBaseMonitor;
 import appeng.api.networking.ticking.TickRateModulation;
 import appeng.api.storage.IMEInventory;
 import appeng.api.storage.IMEMonitorHandlerReceiver;
+import appeng.api.storage.IStorageChannel;
 import appeng.api.storage.channels.IItemStorageChannel;
 import appeng.api.storage.data.IAEItemStack;
 import appeng.api.storage.data.IItemList;
+import appeng.core.AELog;
 import appeng.me.GridAccessException;
 import appeng.me.helpers.IGridProxyable;
 import appeng.me.storage.ITickingMonitor;
 import appeng.util.item.AEItemStack;
+import com.jaquadro.minecraft.storagedrawers.api.capabilities.IItemRepository;
+import it.unimi.dsi.fastutil.objects.Object2ObjectMap;
+import it.unimi.dsi.fastutil.objects.Object2ObjectOpenHashMap;
+import net.minecraft.item.ItemStack;
 
-import javax.annotation.Nonnull;
+import java.util.ArrayList;
+import java.util.Iterator;
+import java.util.List;
+import java.util.Map;
 
 /**
  * Wraps an Item Repository in such a way that it can be used as an IMEInventory for items.
@@ -86,7 +84,7 @@ class ItemRepositoryAdapter implements IMEInventory<IAEItemStack>, IBaseMonitor<
     public IAEItemStack extractItems( IAEItemStack request, Actionable mode, IActionSource src )
     {
         ItemStack requestedItemStack = request.getDefinition();
-        int remainingSize = (int) Math.min( Integer.MAX_VALUE, request.getStackSize());
+        int remainingSize = (int) Math.min( Integer.MAX_VALUE, request.getStackSize() );
 
         final boolean simulate = ( mode == Actionable.SIMULATE );
 
@@ -146,7 +144,7 @@ class ItemRepositoryAdapter implements IMEInventory<IAEItemStack>, IBaseMonitor<
     private void postDifference( Iterable<IAEItemStack> a )
     {
         final Iterator<Map.Entry<IMEMonitorHandlerReceiver<IAEItemStack>, Object>> i = this.listeners.entrySet().iterator();
-        while( i.hasNext() )
+        while ( i.hasNext() )
         {
             final Map.Entry<IMEMonitorHandlerReceiver<IAEItemStack>, Object> l = i.next();
             final IMEMonitorHandlerReceiver<IAEItemStack> key = l.getKey();
@@ -186,7 +184,7 @@ class ItemRepositoryAdapter implements IMEInventory<IAEItemStack>, IBaseMonitor<
 
     private static class InventoryCache
     {
-        private IAEItemStack[] cachedAeStacks = new IAEItemStack[0];
+        private IItemList<IAEItemStack> cachedAeStacks = AEApi.instance().storage().getStorageChannel( IItemStorageChannel.class ).createList();
         private final IItemRepository iItemRepository;
 
         public InventoryCache( IItemRepository iItemRepository )
@@ -196,7 +194,7 @@ class ItemRepositoryAdapter implements IMEInventory<IAEItemStack>, IBaseMonitor<
 
         public IItemList<IAEItemStack> getAvailableItems( IItemList<IAEItemStack> out )
         {
-            Arrays.stream( this.cachedAeStacks ).forEach( out::add );
+            this.cachedAeStacks.forEach( out::add );
             return out;
         }
 
@@ -204,94 +202,51 @@ class ItemRepositoryAdapter implements IMEInventory<IAEItemStack>, IBaseMonitor<
         {
             final List<IAEItemStack> changes = new ArrayList<>();
 
-            List<IAEItemStack> out = this.iItemRepository.getAllItems().stream().map( s -> AEItemStack.fromItemStack( s.itemPrototype ).setStackSize( s.count ) ).collect(Collectors.toList() );
+            IItemList<IAEItemStack> storage = AEApi.instance().storage().getStorageChannel( IItemStorageChannel.class ).createList();
+            this.iItemRepository.getAllItems().stream().map( s -> AEItemStack.fromItemStack( s.itemPrototype ).setStackSize( s.count ) ).forEach( storage::add );
 
-            final int size = out.size();
-
-            // Make room for new slots
-            if( size > this.cachedAeStacks.length )
+            Iterator<IAEItemStack> cachedAeStacksIterator = cachedAeStacks.iterator();
+            while ( cachedAeStacksIterator.hasNext() )
             {
-                this.cachedAeStacks = Arrays.copyOf( this.cachedAeStacks, size );
-            }
-
-            for( int x = 0; x < size; x++ )
-            {
-                // Save the old stuff
-                final IAEItemStack oldAeIS = this.cachedAeStacks[x];
-                final IAEItemStack newIS = out.get( x );
-
-                this.handlePossibleSlotChanges( x, oldAeIS, newIS, changes );
-            }
-
-            // Handle cases where the number of slots actually is lower now than before
-            if( size < this.cachedAeStacks.length )
-            {
-                for( int x = 0; x < this.cachedAeStacks.length; x++ )
+                IAEItemStack cachedStack = cachedAeStacksIterator.next();
+                IAEItemStack storedStack = storage.findPrecise( cachedStack );
+                if( storedStack == null )
                 {
-                    final IAEItemStack aeStack = this.cachedAeStacks[x];
-
-                    if( aeStack != null )
-                    {
-                        final IAEItemStack a = aeStack.copy();
-                        a.setStackSize( -a.getStackSize() );
-                        changes.add( a );
-                    }
+                    changes.add( cachedStack.setStackSize( -cachedStack.getStackSize() ) );
+                    cachedAeStacksIterator.remove();
                 }
+                else if( cachedStack.getStackSize() != storedStack.getStackSize() )
+                {
+                    handleStackSizeChanged( cachedStack, storedStack, changes );
+                }
+            }
 
-                // Reduce the cache size
-                this.cachedAeStacks = Arrays.copyOf( this.cachedAeStacks, size );
+            for( IAEItemStack storedStack : storage )
+            {
+                if( cachedAeStacks.findPrecise( storedStack ) == null )
+                {
+                    cachedAeStacks.add( storedStack );
+                    changes.add( storedStack.copy() );
+                }
             }
 
             return changes;
         }
 
-        private void handlePossibleSlotChanges( int slot, IAEItemStack oldAeIS, IAEItemStack newIS, List<IAEItemStack> changes )
-        {
-            if( oldAeIS != null && oldAeIS.isSameType( newIS ) )
-            {
-                this.handleStackSizeChanged( slot, oldAeIS, newIS, changes );
-            }
-            else
-            {
-                this.handleItemChanged( slot, oldAeIS, newIS, changes );
-            }
-        }
-
-        private void handleStackSizeChanged( int slot, IAEItemStack oldAeIS, IAEItemStack newIS, List<IAEItemStack> changes )
+        private void handleStackSizeChanged( IAEItemStack cachedStack, IAEItemStack storedStack, List<IAEItemStack> changes )
         {
             // Still the same item, but amount might have changed
-            final long diff = newIS.getStackSize() - oldAeIS.getStackSize();
+            final long diff = storedStack.getStackSize() - cachedStack.getStackSize();
 
             if( diff != 0 )
             {
-                final IAEItemStack stack = oldAeIS.copy();
-                stack.setStackSize( newIS.getStackSize() );
+                cachedStack.setStackSize( storedStack.getStackSize() );
 
-                this.cachedAeStacks[slot] = stack;
-
-                final IAEItemStack a = stack.copy();
-                a.setStackSize( diff );
-                changes.add( a );
+                final IAEItemStack diffStack = cachedStack.copy();
+                diffStack.setStackSize( diff );
+                changes.add( diffStack );
             }
         }
 
-        private void handleItemChanged( int slot, IAEItemStack oldAeIS, IAEItemStack newIS, List<IAEItemStack> changes )
-        {
-            // Completely different item
-            this.cachedAeStacks[slot] =  newIS ;
-
-            // If we had a stack previously in this slot, notify the network about its disappearance
-            if( oldAeIS != null )
-            {
-                oldAeIS.setStackSize( -oldAeIS.getStackSize() );
-                changes.add( oldAeIS );
-            }
-
-            // Notify the network about the new stack. Note that this is null if newIS was null
-            if( this.cachedAeStacks[slot] != null )
-            {
-                changes.add( this.cachedAeStacks[slot] );
-            }
-        }
     }
 }

src/main/java/appeng/parts/p2p/PartP2PFEPower.java

@@ -19,11 +19,12 @@
 package appeng.parts.p2p;
 
 
-import java.util.List;
+import java.util.*;
 
 import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
 
+import appeng.me.cache.helpers.TunnelCollection;
 import net.minecraft.item.ItemStack;
 import net.minecraft.tileentity.TileEntity;
 import net.minecraftforge.common.capabilities.Capability;
@@ -42,6 +43,7 @@ public class PartP2PFEPower extends PartP2PTunnel<PartP2PFEPower>
 	private static final IEnergyStorage NULL_ENERGY_STORAGE = new NullEnergyStorage();
 	private final IEnergyStorage inputHandler = new InputEnergyStorage();
 	private final IEnergyStorage outputHandler = new OutputEnergyStorage();
+	private final Queue<PartP2PFEPower> outputs = new ArrayDeque<>();
 
 	public PartP2PFEPower( ItemStack is )
 	{
@@ -108,6 +110,8 @@ public class PartP2PFEPower extends PartP2PTunnel<PartP2PFEPower>
 
 	private class InputEnergyStorage implements IEnergyStorage
 	{
+		private boolean iteratingOutputs;
+
 		@Override
 		public int extractEnergy( int maxExtract, boolean simulate )
 		{
@@ -131,8 +135,14 @@ public class PartP2PFEPower extends PartP2PTunnel<PartP2PFEPower>
 				final int amountPerOutput = maxReceive / outputTunnels;
 				int overflow = amountPerOutput == 0 ? maxReceive : maxReceive % amountPerOutput;
 
-				for( PartP2PFEPower target : PartP2PFEPower.this.getOutputs() )
+				if (outputs.isEmpty())
 				{
+					for ( PartP2PFEPower o : PartP2PFEPower.this.getOutputs())
+					outputs.add( o );
+				}
+
+				while ( !outputs.isEmpty() ) {
+					PartP2PFEPower target = outputs.poll();
 					final IEnergyStorage output = target.getAttachedEnergyStorage();
 					final int toSend = amountPerOutput + overflow;
 					final int received = output.receiveEnergy( toSend, simulate );

src/main/java/appeng/tile/storage/TileIOPort.java

@@ -425,6 +425,7 @@ public class TileIOPort extends AENetworkInvTile implements IUpgradeableHost, IC
 						if( extracted != null )
 						{
 							possible = extracted.getStackSize();
+							extracted.setCraftable( false );
 							final IAEStack failed = Platform.poweredInsert( energy, destination, extracted, this.mySrc );
 
 							if( failed != null )

src/main/java/appeng/util/ReadOnlyCollection.java

@@ -56,6 +56,6 @@ public class ReadOnlyCollection<T> implements IReadOnlyCollection<T>
 	@Override
 	public boolean contains( final Object node )
 	{
-		return this.c.contains( node );
+		return this.c.contains( (T) node );
 	}
 }

src/main/java/appeng/util/item/AEItemStack.java

@@ -1,6 +1,6 @@
 /*
  * This file is part of Applied Energistics 2.
- * Copyright (c) 2013 - 2014, AlgorithmX2, All rights reserved.
+ * Copyright (c) 2013 - 2020, AlgorithmX2, All rights reserved.
  *
  * Applied Energistics 2 is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Lesser General Public License as published by
@@ -18,7 +18,6 @@
 
 package appeng.util.item;
 
-
 import java.util.List;
 import java.util.Objects;
 import java.util.Optional;
@@ -27,347 +26,291 @@ import javax.annotation.Nonnull;
 import javax.annotation.Nullable;
 
 import io.netty.buffer.ByteBuf;
-
 import net.minecraft.item.Item;
 import net.minecraft.item.ItemStack;
 import net.minecraft.nbt.NBTTagCompound;
-import net.minecraft.util.ResourceLocation;
 import net.minecraftforge.fml.common.network.ByteBufUtils;
 import net.minecraftforge.fml.relauncher.Side;
 import net.minecraftforge.fml.relauncher.SideOnly;
 import net.minecraftforge.items.ItemHandlerHelper;
 
-import appeng.api.AEApi;
 import appeng.api.config.FuzzyMode;
 import appeng.api.storage.IStorageChannel;
 import appeng.api.storage.channels.IItemStorageChannel;
 import appeng.api.storage.data.IAEItemStack;
+import appeng.core.Api;
 import appeng.util.Platform;
 
+public final class AEItemStack extends AEStack<IAEItemStack> implements IAEItemStack {
+    private static final String NBT_STACKSIZE = "Cnt";
+    private static final String NBT_REQUESTABLE = "Req";
+    private static final String NBT_CRAFTABLE = "Craft";
 
-public final class AEItemStack extends AEStack<IAEItemStack> implements IAEItemStack
-{
-	private AESharedItemStack sharedStack;
-	private Optional<OreReference> oreReference;
+    private final AESharedItemStack sharedStack;
+    private Optional<OreReference> oreReference;
 
-	@SideOnly( Side.CLIENT )
-	private String displayName;
-	@SideOnly( Side.CLIENT )
-	private List<String> tooltip;
-	@SideOnly( Side.CLIENT )
-	private ResourceLocation uniqueID;
+    @SideOnly(Side.CLIENT)
+    private String displayName;
+    @SideOnly(Side.CLIENT)
+    private List<String> tooltip;
 
-	private AEItemStack( final AEItemStack is )
-	{
-		this.setStackSize( is.getStackSize() );
-		this.setCraftable( is.isCraftable() );
-		this.setCountRequestable( is.getCountRequestable() );
-		this.sharedStack = is.sharedStack;
-		this.oreReference = is.oreReference;
-	}
+    private AEItemStack(final AEItemStack is) {
+        this.setStackSize(is.getStackSize());
+        this.setCraftable(is.isCraftable());
+        this.setCountRequestable(is.getCountRequestable());
+        this.sharedStack = is.sharedStack;
+        this.oreReference = is.oreReference;
+    }
 
-	private AEItemStack( final AESharedItemStack is, long size )
-	{
-		this.sharedStack = is;
-		this.setStackSize( size );
-		this.setCraftable( false );
-		this.setCountRequestable( 0 );
-		this.oreReference = OreHelper.INSTANCE.getOre( is.getDefinition() );
-	}
+    private AEItemStack(final AESharedItemStack is, long size) {
+        this.sharedStack = is;
+        this.setStackSize(size);
+        this.setCraftable(false);
+        this.setCountRequestable(0);
+        this.oreReference = OreHelper.INSTANCE.getOre( is.getDefinition() );
+    }
 
-	@Nullable
-	public static AEItemStack fromItemStack( @Nonnull final ItemStack stack )
-	{
-		if( stack.isEmpty() )
-		{
-			return null;
-		}
+    @Nullable
+    public static AEItemStack fromItemStack(@Nonnull final ItemStack stack) {
+        if (stack.isEmpty()) {
+            return null;
+        }
 
-		return new AEItemStack( AEItemStackRegistry.getRegisteredStack( stack ), stack.getCount() );
-	}
+        return new AEItemStack(AEItemStackRegistry.getRegisteredStack(stack), stack.getCount());
+    }
 
-	public static IAEItemStack fromNBT( final NBTTagCompound i )
-	{
-		if( i == null )
-		{
-			return null;
-		}
+    public static IAEItemStack fromNBT(final NBTTagCompound i) {
+        if (i == null) {
+            return null;
+        }
 
-		final ItemStack itemstack = new ItemStack( i );
-		if( itemstack.isEmpty() )
-		{
-			return null;
-		}
+        final ItemStack itemstack = new ItemStack(i);
+        final AEItemStack item = AEItemStack.fromItemStack(itemstack);
+        if (item == null) {
+            return null;
+        }
 
-		final AEItemStack item = AEItemStack.fromItemStack( itemstack );
-		item.setStackSize( i.getLong( "Cnt" ) );
-		item.setCountRequestable( i.getLong( "Req" ) );
-		item.setCraftable( i.getBoolean( "Craft" ) );
-		return item;
-	}
+        item.setStackSize(i.getLong(NBT_STACKSIZE));
+        item.setCountRequestable(i.getLong(NBT_REQUESTABLE));
+        item.setCraftable(i.getBoolean(NBT_CRAFTABLE));
+        return item;
+    }
 
-	@Override
-	public void writeToNBT( final NBTTagCompound i )
-	{
-		this.getDefinition().writeToNBT( i );
-		i.setLong( "Cnt", this.getStackSize() );
-		i.setLong( "Req", this.getCountRequestable() );
-		i.setBoolean( "Craft", this.isCraftable() );
-	}
+    @Override
+    public void writeToNBT(final NBTTagCompound i) {
+        final NBTTagCompound itemStack = new NBTTagCompound();
+        this.getDefinition().writeToNBT(itemStack);
 
-	public static AEItemStack fromPacket( final ByteBuf data )
-	{
-		final byte mask = data.readByte();
-		final byte stackType = (byte) ( ( mask & 0x0C ) >> 2 );
-		final byte countReqType = (byte) ( ( mask & 0x30 ) >> 4 );
-		final boolean isCraftable = ( mask & 0x40 ) > 0;
+        i.setLong(NBT_STACKSIZE, this.getStackSize());
+        i.setLong(NBT_REQUESTABLE, this.getCountRequestable());
+        i.setBoolean(NBT_CRAFTABLE, this.isCraftable());
+    }
 
-		final ItemStack itemstack = new ItemStack( ByteBufUtils.readTag( data ) );
-		final long stackSize = getPacketValue( stackType, data );
-		final long countRequestable = getPacketValue( countReqType, data );
+    public static AEItemStack fromPacket( final ByteBuf data )
+    {
+        final byte mask = data.readByte();
+        final byte stackType = (byte) ( ( mask & 0x0C ) >> 2 );
+        final byte countReqType = (byte) ( ( mask & 0x30 ) >> 4 );
+        final boolean isCraftable = ( mask & 0x40 ) > 0;
 
-		if( itemstack.isEmpty() )
-		{
-			return null;
-		}
+        final ItemStack itemstack = new ItemStack( ByteBufUtils.readTag( data ) );
+        final long stackSize = getPacketValue( stackType, data );
+        final long countRequestable = getPacketValue( countReqType, data );
 
-		final AEItemStack item = new AEItemStack( AEItemStackRegistry.getRegisteredStack( itemstack ), stackSize );
-		item.setCountRequestable( countRequestable );
-		item.setCraftable( isCraftable );
-		return item;
-	}
+        if( itemstack.isEmpty() )
+        {
+            return null;
+        }
 
-	@Override
-	public void writeToPacket( final ByteBuf i )
-	{
-		final byte mask = (byte) ( ( this.getType( this.getStackSize() ) << 2 ) | ( this
-				.getType( this.getCountRequestable() ) << 4 ) | ( (byte) ( this.isCraftable() ? 1 : 0 ) << 6 ) | ( this.hasTagCompound() ? 1 : 0 ) << 7 );
+        final AEItemStack item = new AEItemStack( AEItemStackRegistry.getRegisteredStack( itemstack ), stackSize );
+        item.setCountRequestable( countRequestable );
+        item.setCraftable( isCraftable );
+        return item;
+    }
 
-		i.writeByte( mask );
-		ByteBufUtils.writeTag( i, this.getDefinition().serializeNBT() );
-		this.putPacketValue( i, this.getStackSize() );
-		this.putPacketValue( i, this.getCountRequestable() );
-	}
+    @Override
+    public void writeToPacket( final ByteBuf i )
+    {
+        final byte mask = (byte) ( ( this.getType( this.getStackSize() ) << 2 ) | ( this
+                .getType( this.getCountRequestable() ) << 4 ) | ( (byte) ( this.isCraftable() ? 1 : 0 ) << 6 ) | ( this.hasTagCompound() ? 1 : 0 ) << 7 );
 
-	@Override
-	public void add( final IAEItemStack option )
-	{
-		if( option == null )
-		{
-			return;
-		}
+        i.writeByte( mask );
+        ByteBufUtils.writeTag( i, this.getDefinition().serializeNBT() );
+        this.putPacketValue( i, this.getStackSize() );
+        this.putPacketValue( i, this.getCountRequestable() );
+    }
 
-		this.incStackSize( option.getStackSize() );
-		this.setCountRequestable( this.getCountRequestable() + option.getCountRequestable() );
-		this.setCraftable( this.isCraftable() || option.isCraftable() );
-	}
+    @Override
+    public void add(final IAEItemStack option) {
+        if (option == null) {
+            return;
+        }
 
-	@Override
-	public boolean fuzzyComparison( final IAEItemStack other, final FuzzyMode mode )
-	{
-		if( mode == FuzzyMode.IGNORE_ALL && OreHelper.INSTANCE.sameOre( this, other ) )
-		{
-			return true;
-		}
+        this.incStackSize(option.getStackSize());
+        this.setCountRequestable(this.getCountRequestable() + option.getCountRequestable());
+        this.setCraftable(this.isCraftable() || option.isCraftable());
+    }
 
-		final ItemStack itemStack = this.getDefinition();
-		final ItemStack otherStack = other.getDefinition();
+    @Override
+    public boolean fuzzyComparison(final IAEItemStack other, final FuzzyMode mode) {
+        final ItemStack itemStack = this.getDefinition();
+        final ItemStack otherStack = other.getDefinition();
 
-		return this.fuzzyItemStackComparison( itemStack, otherStack, mode );
-	}
+        return this.fuzzyItemStackComparison(itemStack, otherStack, mode);
+    }
 
-	@Override
-	public IAEItemStack copy()
-	{
-		return new AEItemStack( this );
-	}
+    @Override
+    public IAEItemStack copy() {
+        return new AEItemStack(this);
+    }
 
-	@Override
-	public boolean isItem()
-	{
-		return true;
-	}
+    @Override
+    public boolean isItem()
+    {
+        return true;
+    }
 
-	@Override
-	public boolean isFluid()
-	{
-		return false;
-	}
+    @Override
+    public boolean isFluid()
+    {
+        return false;
+    }
 
-	@Override
-	public IStorageChannel<IAEItemStack> getChannel()
-	{
-		return AEApi.instance().storage().getStorageChannel( IItemStorageChannel.class );
-	}
+    @Override
+    public IStorageChannel<IAEItemStack> getChannel() {
+        return Api.INSTANCE.storage().getStorageChannel(IItemStorageChannel.class);
+    }
 
-	@Override
-	public ItemStack createItemStack()
-	{
-		return ItemHandlerHelper.copyStackWithSize( this.getDefinition(), (int) Math.min( Integer.MAX_VALUE, this.getStackSize() ) );
-	}
+    @Override
+    public ItemStack createItemStack() {
+        return ItemHandlerHelper.copyStackWithSize(this.getDefinition(),
+                (int) Math.min(Integer.MAX_VALUE, this.getStackSize()));
+    }
 
-	@Override
-	public Item getItem()
-	{
-		return this.getDefinition().getItem();
-	}
+    @Override
+    public Item getItem() {
+        return this.getDefinition().getItem();
+    }
 
-	@Override
-	public int getItemDamage()
-	{
-		return this.sharedStack.getItemDamage();
-	}
+    @Override
+    public int getItemDamage() {
+        return this.sharedStack.getItemDamage();
+    }
 
-	@Override
-	public boolean sameOre( final IAEItemStack is )
-	{
-		return OreHelper.INSTANCE.sameOre( this, is );
-	}
+    @Override
+    public boolean sameOre( final IAEItemStack is )
+    {
+        return OreHelper.INSTANCE.sameOre( this, is );
+    }
 
-	@Override
-	public boolean isSameType( final IAEItemStack otherStack )
-	{
-		if( otherStack == null )
-		{
-			return false;
-		}
+    @Override
+    public boolean isSameType(final IAEItemStack otherStack) {
+        if (otherStack == null) {
+            return false;
+        }
 
-		return Objects.equals( this.sharedStack, ( (AEItemStack) otherStack ).sharedStack );
-	}
+        return Objects.equals(this.sharedStack, ((AEItemStack) otherStack).sharedStack);
+    }
 
-	@Override
-	public boolean isSameType( final ItemStack otherStack )
-	{
-		if( otherStack.isEmpty() )
-		{
-			return false;
-		}
-		int oldSize = otherStack.getCount();
+    @Override
+    public boolean isSameType(final ItemStack otherStack) {
+        if (otherStack.isEmpty()) {
+            return false;
+        }
+        int oldSize = otherStack.getCount();
 
-		otherStack.setCount( 1 );
-		boolean ret = ItemStack.areItemStacksEqual( this.getDefinition(), otherStack );
-		otherStack.setCount( oldSize );
+        otherStack.setCount(1);
+        boolean ret = ItemStack.areItemStacksEqual(this.getDefinition(), otherStack);
+        otherStack.setCount(oldSize);
 
-		return ret;
-	}
+        return ret;
+    }
 
-	@Override
-	public int hashCode()
-	{
-		return this.sharedStack.hashCode();
-	}
+    @Override
+    public int hashCode() {
+        return this.sharedStack.hashCode();
+    }
 
-	@Override
-	public boolean equals( final Object ia )
-	{
-		if( ia instanceof AEItemStack )
-		{
-			return this.isSameType( (AEItemStack) ia );
-		}
-		else if( ia instanceof ItemStack )
-		{
-			return this.isSameType( (ItemStack) ia );
-		}
-		return false;
-	}
+    @Override
+    public boolean equals(final Object ia) {
+        if (ia instanceof AEItemStack) {
+            return this.isSameType((AEItemStack) ia);
+        } else if (ia instanceof ItemStack) {
+            // this actually breaks the equals contract (being equals to unrelated classes)
+            return equals((ItemStack) ia);
+        }
+        return false;
+    }
 
-	@Override
-	public String toString()
-	{
-		return this.getStackSize() + "x" + this.getDefinition().getItem().getUnlocalizedName() + "@" + this.getDefinition().getItemDamage();
-	}
+    @Override
+    public boolean equals(final ItemStack is) {
+        return this.isSameType(is);
+    }
 
-	@SideOnly( Side.CLIENT )
-	public List<String> getToolTip()
-	{
-		if( this.tooltip == null )
-		{
-			this.tooltip = Platform.getTooltip( this.asItemStackRepresentation() );
-		}
-		return this.tooltip;
-	}
+    @Override
+    public String toString() {
+        return this.getStackSize() + "x" + this.getDefinition().getItem().getRegistryName();
+    }
 
-	@SideOnly( Side.CLIENT )
-	public String getDisplayName()
-	{
-		if( this.displayName == null )
-		{
-			this.displayName = Platform.getItemDisplayName( this.asItemStackRepresentation() );
-		}
-		return this.displayName;
-	}
+    @SideOnly(Side.CLIENT)
+    public List<String> getToolTip() {
+        if (this.tooltip == null) {
+            this.tooltip = Platform.getTooltip(this.asItemStackRepresentation());
+        }
+        return this.tooltip;
+    }
 
-	@SideOnly( Side.CLIENT )
-	public String getModID()
-	{
-		if( this.uniqueID == null )
-		{
-			this.uniqueID = Item.REGISTRY.getNameForObject( this.getDefinition().getItem() );
-		}
+    @SideOnly(Side.CLIENT)
+    public String getDisplayName() {
+        if (this.displayName == null) {
+            this.displayName = Platform.getItemDisplayName(this.asItemStackRepresentation());
+        }
+        return this.displayName;
+    }
 
-		if( this.uniqueID == null )
-		{
-			return "** Null";
-		}
+    @SideOnly(Side.CLIENT)
+    public String getModID() {
+        return this.getDefinition().getItem().getRegistryName().getResourceDomain();
+    }
 
-		return this.uniqueID.getResourceDomain() == null ? "** Null" : this.uniqueID.getResourceDomain();
-	}
+    public Optional<OreReference> getOre()
+    {
+        return this.oreReference;
+    }
 
-	public Optional<OreReference> getOre()
-	{
-		return this.oreReference;
-	}
+    @Override
+    public boolean hasTagCompound() {
+        return this.getDefinition().hasTagCompound();
+    }
 
-	@Override
-	public boolean hasTagCompound()
-	{
-		return this.getDefinition().hasTagCompound();
-	}
+    @Override
+    public ItemStack asItemStackRepresentation() {
+        return this.getDefinition().copy();
+    }
 
-	@Override
-	public ItemStack asItemStackRepresentation()
-	{
-		return this.getDefinition().copy();
-	}
+    @Override
+    public ItemStack getDefinition() {
+        return this.sharedStack.getDefinition();
+    }
 
-	@Override
-	public ItemStack getDefinition()
-	{
-		return this.sharedStack.getDefinition();
-	}
+    AESharedItemStack getSharedStack() {
+        return this.sharedStack;
+    }
 
-	AESharedItemStack getSharedStack()
-	{
-		return this.sharedStack;
-	}
+    private boolean fuzzyItemStackComparison(ItemStack a, ItemStack b, FuzzyMode mode) {
+        if (a.getItem() == b.getItem() && a.getItem().isDamageable()) {
+            if (mode == FuzzyMode.IGNORE_ALL) {
+                return true;
+            } else if (mode == FuzzyMode.PERCENT_99) {
+                return a.getItemDamage() > 1 == b.getItemDamage() > 1;
+            } else {
+                final float percentDamageOfA = (float) a.getItemDamage() / a.getMaxDamage();
+                final float percentDamageOfB = (float) b.getItemDamage() / b.getMaxDamage();
 
-	private boolean fuzzyItemStackComparison( ItemStack a, ItemStack b, FuzzyMode mode )
-	{
-		if( a.getItem() == b.getItem() )
-		{
-			if( a.getItem().isDamageable() )
-			{
-				if( mode == FuzzyMode.IGNORE_ALL )
-				{
-					return true;
-				}
-				else if( mode == FuzzyMode.PERCENT_99 )
-				{
-					return ( a.getItemDamage() > 1 ) == ( b.getItemDamage() > 1 );
-				}
-				else
-				{
-					final float percentDamageOfA = (float) a.getItemDamage() / (float) a.getMaxDamage();
-					final float percentDamageOfB = (float) b.getItemDamage() / (float) b.getMaxDamage();
-
-					return ( percentDamageOfA > mode.breakPoint ) == ( percentDamageOfB > mode.breakPoint );
-				}
-			}
-
-			return a.getMetadata() == b.getMetadata();
-		}
-
-		return false;
-	}
+                return percentDamageOfA > mode.breakPoint == percentDamageOfB > mode.breakPoint;
+            }
+        }
 
+        return false;
+    }
 }

src/main/java/appeng/util/item/AEItemStackRegistry.java

@@ -23,7 +23,6 @@
 
 package appeng.util.item;
 
-
 import java.lang.ref.WeakReference;
 import java.util.WeakHashMap;
 
@@ -31,56 +30,34 @@ import javax.annotation.Nonnull;
 
 import net.minecraft.item.ItemStack;
 
-import appeng.util.Platform;
+public final class AEItemStackRegistry {
+    private static final WeakHashMap<AESharedItemStack, WeakReference<AESharedItemStack>> REGISTRY = new WeakHashMap<>();
 
+    private AEItemStackRegistry() {
+    }
 
-public final class AEItemStackRegistry
-{
-	private static final WeakHashMap<AESharedItemStack, WeakReference<AESharedItemStack>> SERVER_REGISTRY = new WeakHashMap<>();
-	private static final WeakHashMap<AESharedItemStack, WeakReference<AESharedItemStack>> CLIENT_REGISTRY = new WeakHashMap<>();
+    static synchronized AESharedItemStack getRegisteredStack(final @Nonnull ItemStack itemStack) {
+        if (itemStack.isEmpty()) {
+            throw new IllegalArgumentException("stack cannot be empty");
+        }
 
-	private AEItemStackRegistry()
-	{
-	}
+        int oldStackSize = itemStack.getCount();
+        itemStack.setCount(1);
 
-	private static WeakHashMap<AESharedItemStack, WeakReference<AESharedItemStack>> registry()
-	{
-		if( Platform.isClient() )
-		{
-			return CLIENT_REGISTRY;
-		}
-		else
-		{
-			return SERVER_REGISTRY;
-		}
-	}
+        AESharedItemStack search = new AESharedItemStack(itemStack);
+        WeakReference<AESharedItemStack> weak = REGISTRY.get(search);
+        AESharedItemStack ret = null;
 
-	static synchronized AESharedItemStack getRegisteredStack( final @Nonnull ItemStack itemStack )
-	{
-		if( itemStack.isEmpty() )
-		{
-			throw new IllegalArgumentException( "stack cannot be empty" );
-		}
+        if (weak != null) {
+            ret = weak.get();
+        }
 
-		int oldStackSize = itemStack.getCount();
-		itemStack.setCount( 1 );
+        if (ret == null) {
+            ret = new AESharedItemStack(itemStack.copy());
+            REGISTRY.put(ret, new WeakReference<>(ret));
+        }
+        itemStack.setCount(oldStackSize);
 
-		AESharedItemStack search = new AESharedItemStack( itemStack );
-		WeakReference<AESharedItemStack> weak = registry().get( search );
-		AESharedItemStack ret = null;
-
-		if( weak != null )
-		{
-			ret = weak.get();
-		}
-
-		if( ret == null )
-		{
-			ret = new AESharedItemStack( itemStack.copy() );
-			registry().put( ret, new WeakReference<>( ret ) );
-		}
-		itemStack.setCount( oldStackSize );
-
-		return ret;
-	}
+        return ret;
+    }
 }

src/main/java/appeng/util/item/AESharedItemStack.java

@@ -18,263 +18,76 @@
 
 package appeng.util.item;
 
-
 import java.util.Objects;
 
 import com.google.common.base.Preconditions;
 
 import net.minecraft.item.Item;
 import net.minecraft.item.ItemStack;
-import net.minecraft.nbt.NBTTagCompound;
 
-import appeng.api.config.FuzzyMode;
+final class AESharedItemStack {
 
+    private final ItemStack itemStack;
+    private final int itemId;
+    private final int itemDamage;
+    private final int hashCode;
 
-final class AESharedItemStack implements Comparable<AESharedItemStack>
-{
-	private static final NBTTagCompound LOW_TAG = new NBTTagCompound();
-	private static final NBTTagCompound HIGH_TAG = new NBTTagCompound();
+    public AESharedItemStack(final ItemStack itemStack) {
+        this(itemStack, itemStack.getItemDamage());
+    }
 
-	private final ItemStack itemStack;
-	private final int itemId;
-	private final int itemDamage;
-	private final int hashCode;
+    /**
+     * A constructor to explicitly set the damage value and not fetch it from the {@link ItemStack}
+     *
+     * @param itemStack The {@link ItemStack} to filter
+     * @param damage    The damage of the item
+     */
+    private AESharedItemStack(ItemStack itemStack, int damage) {
+        this.itemStack = itemStack;
+        this.itemId = Item.getIdFromItem(itemStack.getItem());
+        this.itemDamage = damage;
 
-	public AESharedItemStack( final ItemStack itemStack )
-	{
-		this.itemStack = itemStack;
-		this.itemId = Item.getIdFromItem( itemStack.getItem() );
-		this.itemDamage = itemStack.getItemDamage();
-		this.hashCode = this.makeHashCode();
-	}
+        // Ensure this is always called last.
+        this.hashCode = this.makeHashCode();
+    }
 
-	Bounds getBounds( final FuzzyMode fuzzy, final boolean ignoreMeta )
-	{
-		return new Bounds( this.itemStack, fuzzy, ignoreMeta );
-	}
+    ItemStack getDefinition() {
+        return this.itemStack;
+    }
 
-	ItemStack getDefinition()
-	{
-		return this.itemStack;
-	}
+    int getItemDamage() {
+        return this.itemDamage;
+    }
 
-	int getItemDamage()
-	{
-		return this.itemDamage;
-	}
+    @Override
+    public int hashCode() {
+        return this.hashCode;
+    }
 
-	int getItemID()
-	{
-		return this.itemId;
-	}
+    @Override
+    public boolean equals(final Object obj) {
+        if (this == obj) {
+            return true;
+        }
+        if (!(obj instanceof AESharedItemStack)) {
+            return false;
+        }
 
-	@Override
-	public int hashCode()
-	{
-		return this.hashCode;
-	}
+        final AESharedItemStack other = (AESharedItemStack) obj;
+        Preconditions.checkState(this.itemStack.getCount() == 1, "ItemStack#getCount() has to be 1");
+        Preconditions.checkArgument(other.getDefinition().getCount() == 1, "ItemStack#getCount() has to be 1");
 
-	@Override
-	public boolean equals( final Object obj )
-	{
-		if( obj instanceof AESharedItemStack )
-		{
-			final AESharedItemStack other = (AESharedItemStack) obj;
+        if (this.itemStack == other.itemStack) {
+            return true;
+        }
+        return ItemStack.areItemStacksEqual(this.itemStack, other.itemStack);
+    }
 
-			Preconditions.checkState( this.itemStack.getCount() == 1, "ItemStack#getCount() has to be 1" );
-			Preconditions.checkArgument( other.getDefinition().getCount() == 1, "ItemStack#getCount() has to be 1" );
+    private int makeHashCode() {
+        return Objects.hash(
+                this.itemId,
+                this.itemDamage,
+                this.itemStack.hasTagCompound() ? this.itemStack.getTagCompound() : 0);
+    }
 
-			if( this.itemStack == other.itemStack )
-			{
-				return true;
-			}
-			return ItemStack.areItemStacksEqual( this.itemStack, other.itemStack );
-		}
-		return false;
-	}
-
-	@Override
-	public int compareTo( final AESharedItemStack b )
-	{
-		Preconditions.checkState( this.itemStack.getCount() == 1, "ItemStack#getCount() has to be 1" );
-		Preconditions.checkArgument( b.getDefinition().getCount() == 1, "ItemStack#getCount() has to be 1" );
-
-		if( this.itemStack == b.getDefinition() )
-		{
-			return 0;
-		}
-
-		final int id = this.itemId - b.itemId;
-		if( id != 0 )
-		{
-			return id;
-		}
-
-		final int damageValue = this.itemDamage - b.itemDamage;
-		if( damageValue != 0 )
-		{
-			return damageValue;
-		}
-
-		final int nbt = this.compareNBT( b.getDefinition() );
-		if( nbt != 0 )
-		{
-			return nbt;
-		}
-
-		if( !this.itemStack.areCapsCompatible( b.getDefinition() ) )
-		{
-			return System.identityHashCode( this.itemStack ) - System.identityHashCode( b.getDefinition() );
-		}
-		return 0;
-	}
-
-	private int compareNBT( final ItemStack b )
-	{
-		if( this.itemStack.getTagCompound() == b.getTagCompound() )
-		{
-			return 0;
-		}
-		if( this.itemStack.getTagCompound() == LOW_TAG || b.getTagCompound() == HIGH_TAG )
-		{
-			return -1;
-		}
-		if( this.itemStack.getTagCompound() == HIGH_TAG || b.getTagCompound() == LOW_TAG )
-		{
-			return 1;
-		}
-		return System.identityHashCode( this.itemStack.getTagCompound() ) - System.identityHashCode( b.getTagCompound() );
-	}
-
-	private int makeHashCode()
-	{
-		return Objects.hash( this.itemId, this.itemDamage, this.itemStack.hasTagCompound() ? this.itemStack.getTagCompound() : 0 );
-	}
-
-	/**
-	 * Creates the lower and upper bounds for a specific shared itemstack.
-	 */
-	public static final class Bounds
-	{
-		/**
-		 * Bounds enforced by {@link ItemStack#isEmpty()}
-		 */
-		private static final int MIN_DAMAGE_VALUE = 0;
-		private static final int MAX_DAMAGE_VALUE = 65535;
-
-		private final AESharedItemStack lower;
-		private final AESharedItemStack upper;
-
-		public Bounds( final ItemStack stack, final FuzzyMode fuzzy, final boolean ignoreMeta )
-		{
-			Preconditions.checkState( !stack.isEmpty(), "ItemStack#isEmpty() has to be false" );
-			Preconditions.checkState( stack.getCount() == 1, "ItemStack#getCount() has to be 1" );
-
-			final NBTTagCompound tag = stack.hasTagCompound() ? stack.getTagCompound() : null;
-
-			this.lower = this.makeLowerBound( stack, tag, fuzzy, ignoreMeta );
-			this.upper = this.makeUpperBound( stack, tag, fuzzy, ignoreMeta );
-		}
-
-		public AESharedItemStack lower()
-		{
-			return this.lower;
-		}
-
-		public AESharedItemStack upper()
-		{
-			return this.upper;
-		}
-
-		private AESharedItemStack makeLowerBound( final ItemStack itemStack, final NBTTagCompound tag, final FuzzyMode fuzzy, final boolean ignoreMeta )
-		{
-			final ItemStack newDef = itemStack.copy();
-
-			if( ignoreMeta )
-			{
-				newDef.setItemDamage( MIN_DAMAGE_VALUE );
-				newDef.setTagCompound( tag );
-			}
-			else
-			{
-				if( newDef.getItem().isDamageable() )
-				{
-					if (itemStack.getMaxDamage() == 0)
-					{
-						newDef.setItemDamage(itemStack.getItemDamage() );
-					}
-					else if ( fuzzy == FuzzyMode.IGNORE_ALL )
-					{
-						newDef.setItemDamage( MIN_DAMAGE_VALUE );
-					}
-					else if( fuzzy == FuzzyMode.PERCENT_99 )
-					{
-						if( itemStack.getItemDamage() == MIN_DAMAGE_VALUE )
-						{
-							newDef.setItemDamage( MIN_DAMAGE_VALUE );
-						}
-						else
-						{
-							newDef.setItemDamage( MIN_DAMAGE_VALUE + 1 );
-						}
-					}
-					else
-					{
-						final int breakpoint = fuzzy.calculateBreakPoint( itemStack.getMaxDamage() );
-						final int damage = breakpoint <= itemStack.getItemDamage() ? breakpoint : 0;
-						newDef.setItemDamage( damage );
-					}
-				}
-				newDef.setTagCompound( LOW_TAG );
-			}
-
-			return new AESharedItemStack( newDef );
-		}
-
-		private AESharedItemStack makeUpperBound( final ItemStack itemStack, final NBTTagCompound tag, final FuzzyMode fuzzy, final boolean ignoreMeta )
-		{
-			final ItemStack newDef = itemStack.copy();
-
-			if( ignoreMeta )
-			{
-				newDef.setItemDamage( MAX_DAMAGE_VALUE );
-				newDef.setTagCompound( tag );
-			}
-			else
-			{
-				if( newDef.getItem().isDamageable() )
-				{
-					if (itemStack.getMaxDamage() == 0)
-					{
-						newDef.setItemDamage(itemStack.getItemDamage() );
-					}
-					else if ( fuzzy == FuzzyMode.IGNORE_ALL )
-					{
-						newDef.setItemDamage( itemStack.getMaxDamage() + 1 );
-					}
-					else if( fuzzy == FuzzyMode.PERCENT_99 )
-					{
-						if( itemStack.getItemDamage() == MIN_DAMAGE_VALUE )
-						{
-							newDef.setItemDamage( MIN_DAMAGE_VALUE );
-						}
-						else
-						{
-							newDef.setItemDamage( itemStack.getMaxDamage() + 1 );
-						}
-					}
-					else
-					{
-						final int breakpoint = fuzzy.calculateBreakPoint( itemStack.getMaxDamage() );
-						final int damage = itemStack.getItemDamage() < breakpoint ? breakpoint - 1 : itemStack.getMaxDamage() + 1;
-						newDef.setItemDamage( damage );
-					}
-				}
-				newDef.setTagCompound( HIGH_TAG );
-			}
-
-			return new AESharedItemStack( newDef );
-		}
-
-	}
 }

src/main/java/appeng/util/item/AEStack.java

@@ -18,169 +18,152 @@
 
 package appeng.util.item;
 
-
+import appeng.api.storage.data.IAEStack;
 import io.netty.buffer.ByteBuf;
 
-import appeng.api.storage.data.IAEStack;
 
+public abstract class AEStack<T extends IAEStack<T>> implements IAEStack<T> {
 
-public abstract class AEStack<StackType extends IAEStack<StackType>> implements IAEStack<StackType>
-{
+    private boolean isCraftable;
+    private long stackSize;
+    private long countRequestable;
 
-	private boolean isCraftable;
-	private long stackSize;
-	private long countRequestable;
+    protected static long getPacketValue( final byte type, final ByteBuf tag )
+    {
+        if( type == 0 )
+        {
+            long l = tag.readByte();
+            l -= Byte.MIN_VALUE;
+            return l;
+        }
+        else if( type == 1 )
+        {
+            long l = tag.readShort();
+            l -= Short.MIN_VALUE;
+            return l;
+        }
+        else if( type == 2 )
+        {
+            long l = tag.readInt();
+            l -= Integer.MIN_VALUE;
+            return l;
+        }
 
-	protected static long getPacketValue( final byte type, final ByteBuf tag )
-	{
-		if( type == 0 )
-		{
-			long l = tag.readByte();
-			l -= Byte.MIN_VALUE;
-			return l;
-		}
-		else if( type == 1 )
-		{
-			long l = tag.readShort();
-			l -= Short.MIN_VALUE;
-			return l;
-		}
-		else if( type == 2 )
-		{
-			long l = tag.readInt();
-			l -= Integer.MIN_VALUE;
-			return l;
-		}
+        return tag.readLong();
+    }
 
-		return tag.readLong();
-	}
+    @Override
+    public long getStackSize() {
+        return this.stackSize;
+    }
 
-	@Override
-	public long getStackSize()
-	{
-		return this.stackSize;
-	}
+    @Override
+    public T setStackSize(final long ss) {
+        this.stackSize = ss;
+        return (T) this;
+    }
 
-	@Override
-	public StackType setStackSize( final long ss )
-	{
-		this.stackSize = ss;
-		return (StackType) this;
-	}
+    @Override
+    public long getCountRequestable() {
+        return this.countRequestable;
+    }
 
-	@Override
-	public long getCountRequestable()
-	{
-		return this.countRequestable;
-	}
+    @Override
+    public T setCountRequestable(final long countRequestable) {
+        this.countRequestable = countRequestable;
+        return (T) this;
+    }
 
-	@Override
-	public StackType setCountRequestable( final long countRequestable )
-	{
-		this.countRequestable = countRequestable;
-		return (StackType) this;
-	}
+    @Override
+    public boolean isCraftable() {
+        return this.isCraftable;
+    }
 
-	@Override
-	public boolean isCraftable()
-	{
-		return this.isCraftable;
-	}
+    @Override
+    public T setCraftable(final boolean isCraftable) {
+        this.isCraftable = isCraftable;
+        return (T) this;
+    }
 
-	@Override
-	public StackType setCraftable( final boolean isCraftable )
-	{
-		this.isCraftable = isCraftable;
-		return (StackType) this;
-	}
+    @Override
+    public T reset() {
+        this.stackSize = 0;
+        this.setCountRequestable(0);
+        this.setCraftable(false);
+        return (T) this;
+    }
 
-	@Override
-	public StackType reset()
-	{
-		this.stackSize = 0;
-		// priority = Integer.MIN_VALUE;
-		this.setCountRequestable( 0 );
-		this.setCraftable( false );
-		return (StackType) this;
-	}
+    @Override
+    public T empty() {
+        final T dup = this.copy();
+        dup.reset();
+        return dup;
+    }
 
-	@Override
-	public StackType empty()
-	{
-		final StackType dup = this.copy();
-		dup.reset();
-		return dup;
-	}
+    @Override
+    public boolean isMeaningful() {
+        return this.stackSize != 0 || this.countRequestable > 0 || this.isCraftable;
+    }
 
-	@Override
-	public boolean isMeaningful()
-	{
-		return this.stackSize != 0 || this.countRequestable > 0 || this.isCraftable;
-	}
+    @Override
+    public void incStackSize(final long i) {
+        this.stackSize += i;
+    }
 
-	@Override
-	public void incStackSize( final long i )
-	{
-		this.stackSize += i;
-	}
+    @Override
+    public void decStackSize(final long i) {
+        this.stackSize -= i;
+    }
 
-	@Override
-	public void decStackSize( final long i )
-	{
-		this.stackSize -= i;
-	}
+    @Override
+    public void incCountRequestable(final long i) {
+        this.countRequestable += i;
+    }
 
-	@Override
-	public void incCountRequestable( final long i )
-	{
-		this.countRequestable += i;
-	}
+    @Override
+    public void decCountRequestable(final long i) {
+        this.countRequestable -= i;
+    }
 
-	@Override
-	public void decCountRequestable( final long i )
-	{
-		this.countRequestable -= i;
-	}
+    protected byte getType( final long num )
+    {
+        if( num <= 255 )
+        {
+            return 0;
+        }
+        else if( num <= 65535 )
+        {
+            return 1;
+        }
+        else if( num <= 4294967295L )
+        {
+            return 2;
+        }
+        else
+        {
+            return 3;
+        }
+    }
 
-	protected byte getType( final long num )
-	{
-		if( num <= 255 )
-		{
-			return 0;
-		}
-		else if( num <= 65535 )
-		{
-			return 1;
-		}
-		else if( num <= 4294967295L )
-		{
-			return 2;
-		}
-		else
-		{
-			return 3;
-		}
-	}
+    protected abstract boolean hasTagCompound();
 
-	protected abstract boolean hasTagCompound();
-
-	protected void putPacketValue( final ByteBuf tag, final long num )
-	{
-		if( num <= 255 )
-		{
-			tag.writeByte( (byte) ( num + Byte.MIN_VALUE ) );
-		}
-		else if( num <= 65535 )
-		{
-			tag.writeShort( (short) ( num + Short.MIN_VALUE ) );
-		}
-		else if( num <= 4294967295L )
-		{
-			tag.writeInt( (int) ( num + Integer.MIN_VALUE ) );
-		}
-		else
-		{
-			tag.writeLong( num );
-		}
-	}
+    protected void putPacketValue( final ByteBuf tag, final long num )
+    {
+        if( num <= 255 )
+        {
+            tag.writeByte( (byte) ( num + Byte.MIN_VALUE ) );
+        }
+        else if( num <= 65535 )
+        {
+            tag.writeShort( (short) ( num + Short.MIN_VALUE ) );
+        }
+        else if( num <= 4294967295L )
+        {
+            tag.writeInt( (int) ( num + Integer.MIN_VALUE ) );
+        }
+        else
+        {
+            tag.writeLong( num );
+        }
+    }
 }

src/main/java/appeng/util/item/FuzzyItemVariantList.java

@@ -0,0 +1,190 @@
+/*
+ * This file is part of Applied Energistics 2.
+ * Copyright (c) 2021, TeamAppliedEnergistics, All rights reserved.
+ *
+ * Applied Energistics 2 is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Applied Energistics 2 is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with Applied Energistics 2.  If not, see <http://www.gnu.org/licenses/lgpl>.
+ */
+
+package appeng.util.item;
+
+import java.util.Collection;
+import java.util.Comparator;
+import java.util.Map;
+
+import com.google.common.base.Preconditions;
+
+import net.minecraft.item.ItemStack;
+
+import it.unimi.dsi.fastutil.objects.Object2ObjectAVLTreeMap;
+import it.unimi.dsi.fastutil.objects.Object2ObjectSortedMap;
+
+import appeng.api.config.FuzzyMode;
+import appeng.api.storage.data.IAEItemStack;
+
+/**
+ * This variant list is optimized for damageable items, and supports selecting durability ranges with
+ * {@link #findFuzzy(IAEItemStack, FuzzyMode)}.
+ */
+class FuzzyItemVariantList extends ItemVariantList {
+
+    static final SharedStackComparator COMPARATOR = new SharedStackComparator();
+
+    // NOTE: We only use Object as they key here so we can pass our special DamageBounds to the subMap method.
+    // We NEVER put any keys in this map that are not AESharedItemStacks.
+    private final Object2ObjectSortedMap<Object, IAEItemStack> records = new Object2ObjectAVLTreeMap<>(COMPARATOR);
+
+    @Override
+    public Collection<IAEItemStack> findFuzzy(final IAEItemStack filter, final FuzzyMode fuzzy) {
+        ItemStack itemStack = filter.getDefinition();
+
+        ItemDamageBound lowerBound = makeLowerBound(itemStack, fuzzy);
+        ItemDamageBound upperBound = makeUpperBound(itemStack, fuzzy);
+        Preconditions.checkState(lowerBound.itemDamage > upperBound.itemDamage);
+
+        return this.records.subMap(lowerBound, upperBound).values();
+    }
+
+    @SuppressWarnings("unchecked")
+    @Override
+    Map<AESharedItemStack, IAEItemStack> getRecords() {
+        // We ensure on our end that we NEVER use anything but AESharedItemStack as the key in this map
+        return (Map<AESharedItemStack, IAEItemStack>) (Object) this.records;
+    }
+
+    static class ItemDamageBound {
+        final int itemDamage;
+
+        public ItemDamageBound(int itemDamage) {
+            this.itemDamage = itemDamage;
+        }
+    }
+
+    /**
+     * This comparator creates a strict and total ordering over all {@link AESharedItemStack} of the same item. To
+     * support selecting ranges of durability, it is defined for type {@link Object} and also accepts
+     * {@link ItemDamageBound} as an argument to compare against.
+     */
+    static class SharedStackComparator implements Comparator<Object> {
+        @Override
+        public int compare(Object a, Object b) {
+            // Either argument can either be a damage bound or a shared item stack
+            // Since we never put damage bounds into the map as keys, only one
+            // of the two arguments can possibly be a bound
+            ItemDamageBound boundA = null;
+            AESharedItemStack stackA = null;
+            int itemDamageA;
+            if (a instanceof ItemDamageBound) {
+                boundA = (ItemDamageBound) a;
+                itemDamageA = boundA.itemDamage;
+            } else {
+                stackA = (AESharedItemStack) a;
+                itemDamageA = stackA.getItemDamage();
+            }
+            ItemDamageBound boundB = null;
+            AESharedItemStack stackB = null;
+            int itemDamageB;
+            if (b instanceof ItemDamageBound) {
+                boundB = (ItemDamageBound) b;
+                itemDamageB = boundB.itemDamage;
+            } else {
+                stackB = (AESharedItemStack) b;
+                itemDamageB = stackB.getItemDamage();
+            }
+
+            // When either argument is a damage bound, we just compare the damage values because it is used
+            // only to get a certain damage range out of the map.
+            if (boundA != null || boundB != null) {
+                return Integer.compare(itemDamageB, itemDamageA);
+            }
+
+            ItemStack itemStackA = stackA.getDefinition();
+            ItemStack itemStackB = stackB.getDefinition();
+            Preconditions.checkState(itemStackA.getCount() == 1, "ItemStack#getCount() has to be 1");
+            Preconditions.checkArgument(itemStackB.getCount() == 1, "ItemStack#getCount() has to be 1");
+
+            if (itemStackA == itemStackB) {
+                return 0;
+            }
+
+            // Damaged items are sorted before undamaged items
+            final int damageValue = Integer.compare(itemDamageB, itemDamageA);
+            if (damageValue != 0) {
+                return damageValue;
+            }
+
+            // As a final tie breaker, order by the object identity of the item stack
+            // While this will order seemingly at random, we only need the order of
+            // damage values to be predictable, while still having to satisfy the
+            // complete order requirements of the sorted map
+            return Long.compare(System.identityHashCode(itemStackA), System.identityHashCode(itemStackB));
+        }
+    }
+
+    /**
+     * Minecraft reverses the damage values. So anything with a damage of 0 is undamaged and increases the more damaged
+     * the item is.
+     * <p>
+     * Further the used subMap follows [MAX_DAMAGE, MIN_DAMAGE), so to include undamaged items, we have to start with a
+     * lower damage value than 0, while it is fine to use {@link ItemStack#getMaxDamage()} for the upper bound.
+     */
+    private static final int MIN_DAMAGE_VALUE = -1;
+
+    /*
+     * Keep in mind that the stack order is from most damaged to least damaged, so this lower bound will actually be a
+     * higher number than the upper bound.
+     */
+    static ItemDamageBound makeLowerBound(final ItemStack stack, final FuzzyMode fuzzy)
+    {
+        Preconditions.checkState( stack.getItem().isDamageable(), "Item#isDamageable() has to be true" );
+
+        int damage;
+        if( fuzzy == FuzzyMode.IGNORE_ALL )
+        {
+            if( stack.getMaxDamage() == 0 )
+            {
+                damage = stack.getItemDamage();
+            }
+            else
+            {
+                damage = stack.getMaxDamage();
+            }
+        }
+        else
+        {
+            final int breakpoint = fuzzy.calculateBreakPoint( stack.getMaxDamage() );
+            damage = stack.getItemDamage() <= breakpoint ? breakpoint : stack.getMaxDamage();
+        }
+
+        return new ItemDamageBound( damage );
+    }
+
+    /*
+     * Keep in mind that the stack order is from most damaged to least damaged, so this upper bound will actually be a
+     * lower number than the lower bound. It also is exclusive.
+     */
+    static ItemDamageBound makeUpperBound(final ItemStack stack, final FuzzyMode fuzzy) {
+        Preconditions.checkState(stack.getItem().isDamageable(), "Item#isDamageable() has to be true");
+
+        int damage;
+        if (fuzzy == FuzzyMode.IGNORE_ALL) {
+            damage = MIN_DAMAGE_VALUE;
+        } else {
+            final int breakpoint = fuzzy.calculateBreakPoint(stack.getMaxDamage());
+            damage = stack.getItemDamage() <= breakpoint ? MIN_DAMAGE_VALUE : breakpoint;
+        }
+
+        return new ItemDamageBound(damage);
+    }
+
+}

src/main/java/appeng/util/item/ItemList.java

@@ -1,6 +1,6 @@
 /*
  * This file is part of Applied Energistics 2.
- * Copyright (c) 2013 - 2015, AlgorithmX2, All rights reserved.
+ * Copyright (c) 2013 - 2020, AlgorithmX2, All rights reserved.
  *
  * Applied Energistics 2 is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Lesser General Public License as published by
@@ -18,212 +18,196 @@
 
 package appeng.util.item;
 
-
-import java.util.ArrayList;
 import java.util.Collection;
 import java.util.Collections;
+import java.util.ConcurrentModificationException;
 import java.util.Iterator;
-import java.util.NavigableMap;
-import java.util.concurrent.ConcurrentSkipListMap;
+import java.util.NoSuchElementException;
+import java.util.concurrent.atomic.AtomicInteger;
 
-import net.minecraftforge.oredict.OreDictionary;
+import net.minecraft.item.Item;
+
+import it.unimi.dsi.fastutil.objects.Reference2ObjectMap;
+import it.unimi.dsi.fastutil.objects.Reference2ObjectOpenHashMap;
 
 import appeng.api.config.FuzzyMode;
 import appeng.api.storage.data.IAEItemStack;
 import appeng.api.storage.data.IItemList;
-import appeng.util.item.AESharedItemStack.Bounds;
 
+public final class ItemList implements IItemList<IAEItemStack> {
 
-public final class ItemList implements IItemList<IAEItemStack>
-{
+    private final Reference2ObjectMap<Item, ItemVariantList> records = new Reference2ObjectOpenHashMap<>();
+    /**
+     * We increment this version field everytime an attempt to mutate this item list (or potentially one of its
+     * sub-lists) is made. Iterators will copy the version when they are created and compare it against the current
+     * version whenever they advance to trigger a {@link ConcurrentModificationException}.
+     */
+    private final AtomicInteger version = new AtomicInteger(0);
 
-	private final NavigableMap<AESharedItemStack, IAEItemStack> records = new ConcurrentSkipListMap<>();
+    @Override
+    public IAEItemStack findPrecise(final IAEItemStack itemStack) {
+        if (itemStack == null) {
+            return null;
+        }
 
-	@Override
-	public void add( final IAEItemStack option )
-	{
-		if( option == null )
-		{
-			return;
-		}
+        ItemVariantList record = this.records.get(itemStack.getItem());
+        return record != null ? record.findPrecise(itemStack) : null;
+    }
 
-		final IAEItemStack st = this.records.get( ( (AEItemStack) option ).getSharedStack() );
+    @Override
+    public Collection<IAEItemStack> findFuzzy(final IAEItemStack filter, final FuzzyMode fuzzy) {
+        if (filter == null) {
+            return Collections.emptyList();
+        }
 
-		if( st != null )
-		{
-			st.add( option );
-			return;
-		}
+        ItemVariantList record = this.records.get(filter.getItem());
+        return record != null ? record.findFuzzy(filter, fuzzy) : Collections.emptyList();
+    }
 
-		final IAEItemStack opt = option.copy();
+    @Override
+    public boolean isEmpty() {
+        return !this.iterator().hasNext();
+    }
 
-		this.putItemRecord( opt );
-	}
+    @Override
+    public void add(final IAEItemStack itemStack) {
+        version.incrementAndGet();
 
-	@Override
-	public IAEItemStack findPrecise( final IAEItemStack itemStack )
-	{
-		if( itemStack == null )
-		{
-			return null;
-		}
+        if (itemStack == null) {
+            return;
+        }
 
-		return this.records.get( ( (AEItemStack) itemStack ).getSharedStack() );
-	}
+        this.getOrCreateRecord(itemStack.getItem()).add(itemStack);
+    }
 
-	@Override
-	public Collection<IAEItemStack> findFuzzy( final IAEItemStack filter, final FuzzyMode fuzzy )
-	{
-		if( filter == null )
-		{
-			return Collections.emptyList();
-		}
+    @Override
+    public void addStorage(final IAEItemStack itemStack) {
+        version.incrementAndGet();
 
-		final AEItemStack ais = (AEItemStack) filter;
+        if (itemStack == null) {
+            return;
+        }
 
-		return ais.getOre().map( or ->
-		{
-			if( or.getAEEquivalents().size() == 1 )
-			{
-				final IAEItemStack is = or.getAEEquivalents().get( 0 );
+        this.getOrCreateRecord(itemStack.getItem()).addStorage(itemStack);
+    }
 
-				return this.findFuzzyDamage( is, fuzzy, is.getItemDamage() == OreDictionary.WILDCARD_VALUE );
-			}
-			else
-			{
-				final Collection<IAEItemStack> output = new ArrayList<>();
+    @Override
+    public void addCrafting(final IAEItemStack itemStack) {
+        version.incrementAndGet();
 
-				for( final IAEItemStack is : or.getAEEquivalents() )
-				{
-					output.addAll( this.findFuzzyDamage( is, fuzzy, is.getItemDamage() == OreDictionary.WILDCARD_VALUE ) );
-				}
+        if (itemStack == null) {
+            return;
+        }
 
-				return output;
-			}
-		} ).orElse( this.findFuzzyDamage( ais, fuzzy, false ) );
-	}
+        this.getOrCreateRecord(itemStack.getItem()).addCrafting(itemStack);
+    }
 
-	@Override
-	public boolean isEmpty()
-	{
-		return !this.iterator().hasNext();
-	}
+    @Override
+    public void addRequestable(final IAEItemStack itemStack) {
+        version.incrementAndGet();
 
-	@Override
-	public void addStorage( final IAEItemStack option )
-	{
-		if( option == null )
-		{
-			return;
-		}
+        if (itemStack == null) {
+            return;
+        }
 
-		final IAEItemStack st = this.records.get( ( (AEItemStack) option ).getSharedStack() );
+        this.getOrCreateRecord(itemStack.getItem()).addRequestable(itemStack);
+    }
 
-		if( st != null )
-		{
-			st.incStackSize( option.getStackSize() );
-			return;
-		}
+    @Override
+    public IAEItemStack getFirstItem() {
+        for (final IAEItemStack stackType : this) {
+            return stackType;
+        }
 
-		final IAEItemStack opt = option.copy();
+        return null;
+    }
 
-		this.putItemRecord( opt );
-	}
+    @Override
+    public int size() {
+        int size = 0;
+        for (ItemVariantList entry : records.values()) {
+            size += entry.size();
+        }
 
-	/*
-	 * public void clean() { Iterator<StackType> i = iterator(); while (i.hasNext()) { StackType AEI =
-	 * i.next(); if ( !AEI.isMeaningful() ) i.remove(); } }
-	 */
+        return size;
+    }
 
-	@Override
-	public void addCrafting( final IAEItemStack option )
-	{
-		if( option == null )
-		{
-			return;
-		}
+    @Override
+    public Iterator<IAEItemStack> iterator() {
+        return new ChainedIterator(this.records.values().iterator(), version);
+    }
 
-		final IAEItemStack st = this.records.get( ( (AEItemStack) option ).getSharedStack() );
+    @Override
+    public void resetStatus() {
+        for (final IAEItemStack i : this) {
+            i.reset();
+        }
+    }
 
-		if( st != null )
-		{
-			st.setCraftable( true );
-			return;
-		}
+    private ItemVariantList getOrCreateRecord(Item item) {
+        return this.records.computeIfAbsent(item, this::makeRecordMap);
+    }
 
-		final IAEItemStack opt = option.copy();
-		opt.setStackSize( 0 );
-		opt.setCraftable( true );
+    private ItemVariantList makeRecordMap(Item item) {
+        if (item.isDamageable()) {
+            return new FuzzyItemVariantList();
+        } else {
+            return new NormalItemVariantList();
+        }
+    }
 
-		this.putItemRecord( opt );
-	}
+    /**
+     * Iterates over multiple item lists as if they were one list.
+     */
+    private static class ChainedIterator implements Iterator<IAEItemStack> {
 
-	@Override
-	public void addRequestable( final IAEItemStack option )
-	{
-		if( option == null )
-		{
-			return;
-		}
+        private final AtomicInteger parentVersion;
+        private final int version;
+        private final Iterator<ItemVariantList> parent;
+        private Iterator<IAEItemStack> next;
 
-		final IAEItemStack st = this.records.get( ( (AEItemStack) option ).getSharedStack() );
+        public ChainedIterator(Iterator<ItemVariantList> iterator, AtomicInteger parentVersion) {
+            this.parent = iterator;
+            this.parentVersion = parentVersion;
+            this.version = parentVersion.get();
+            this.ensureItems();
+        }
 
-		if( st != null )
-		{
-			st.setCountRequestable( st.getCountRequestable() + option.getCountRequestable() );
-			return;
-		}
+        @Override
+        public boolean hasNext() {
+            return next != null && next.hasNext();
+        }
 
-		final IAEItemStack opt = option.copy();
-		opt.setStackSize( 0 );
-		opt.setCraftable( false );
-		opt.setCountRequestable( option.getCountRequestable() );
+        @Override
+        public IAEItemStack next() {
+            if (this.next == null) {
+                throw new NoSuchElementException();
+            }
+            if (this.version != this.parentVersion.get()) {
+                throw new ConcurrentModificationException();
+            }
 
-		this.putItemRecord( opt );
-	}
+            IAEItemStack result = this.next.next();
+            this.ensureItems();
+            return result;
+        }
 
-	@Override
-	public IAEItemStack getFirstItem()
-	{
-		for( final IAEItemStack stackType : this )
-		{
-			return stackType;
-		}
+        private void ensureItems() {
+            if (hasNext()) {
+                return; // Still items left in the current one
+            }
 
-		return null;
-	}
+            // Find the next iterator willing to return some items...
+            while (this.parent.hasNext()) {
+                this.next = this.parent.next().iterator();
 
-	@Override
-	public int size()
-	{
-		return this.records.size();
-	}
+                if (this.next.hasNext()) {
+                    return; // Found one!
+                }
+            }
 
-	@Override
-	public Iterator<IAEItemStack> iterator()
-	{
-		return new MeaningfulItemIterator<>( this.records.values().iterator() );
-	}
-
-	@Override
-	public void resetStatus()
-	{
-		for( final IAEItemStack i : this )
-		{
-			i.reset();
-		}
-	}
-
-	private IAEItemStack putItemRecord( final IAEItemStack itemStack )
-	{
-		return this.records.put( ( (AEItemStack) itemStack ).getSharedStack(), itemStack );
-	}
-
-	private Collection<IAEItemStack> findFuzzyDamage( final IAEItemStack filter, final FuzzyMode fuzzy, final boolean ignoreMeta )
-	{
-		final AEItemStack itemStack = (AEItemStack) filter;
-		final Bounds bounds = itemStack.getSharedStack().getBounds( fuzzy, ignoreMeta );
-
-		return this.records.subMap( bounds.lower(), true, bounds.upper(), true ).descendingMap().values();
-	}
+            // No more items
+            this.next = null;
+        }
+    }
 }

src/main/java/appeng/util/item/ItemVariantList.java

@@ -0,0 +1,118 @@
+/*
+ * This file is part of Applied Energistics 2.
+ * Copyright (c) 2021, TeamAppliedEnergistics, All rights reserved.
+ *
+ * Applied Energistics 2 is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Applied Energistics 2 is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with Applied Energistics 2.  If not, see <http://www.gnu.org/licenses/lgpl>.
+ */
+
+package appeng.util.item;
+
+import java.util.Collection;
+import java.util.Iterator;
+import java.util.Map;
+
+import appeng.api.config.FuzzyMode;
+import appeng.api.storage.data.IAEItemStack;
+
+/**
+ * Stores variants of a single type of {@link net.minecraft.item.Item}, i.e. versions with different durability, or
+ * different NBT or capabilities.
+ */
+abstract class ItemVariantList {
+
+    public void add(final IAEItemStack option) {
+        final IAEItemStack st = this.getRecords().get(((AEItemStack) option).getSharedStack());
+
+        if (st != null) {
+            st.add(option);
+            return;
+        }
+
+        final IAEItemStack opt = option.copy();
+
+        this.putItemRecord(opt);
+    }
+
+    public IAEItemStack findPrecise(final IAEItemStack itemStack) {
+        return this.getRecords().get(((AEItemStack) itemStack).getSharedStack());
+    }
+
+    public void addStorage(final IAEItemStack option) {
+        final IAEItemStack st = this.getRecords().get(((AEItemStack) option).getSharedStack());
+
+        if (st != null) {
+            st.incStackSize(option.getStackSize());
+            return;
+        }
+
+        final IAEItemStack opt = option.copy();
+
+        this.putItemRecord(opt);
+    }
+
+    public void addCrafting(final IAEItemStack option) {
+        final IAEItemStack st = this.getRecords().get(((AEItemStack) option).getSharedStack());
+
+        if (st != null) {
+            st.setCraftable(true);
+            return;
+        }
+
+        final IAEItemStack opt = option.copy();
+        opt.setStackSize(0);
+        opt.setCraftable(true);
+
+        this.putItemRecord(opt);
+    }
+
+    public void addRequestable(final IAEItemStack option) {
+        final IAEItemStack st = this.getRecords().get(((AEItemStack) option).getSharedStack());
+
+        if (st != null) {
+            st.setCountRequestable(st.getCountRequestable() + option.getCountRequestable());
+            return;
+        }
+
+        final IAEItemStack opt = option.copy();
+        opt.setStackSize(0);
+        opt.setCraftable(false);
+        opt.setCountRequestable(option.getCountRequestable());
+
+        this.putItemRecord(opt);
+    }
+
+    public int size() {
+        int size = 0;
+        for (IAEItemStack entry : getRecords().values()) {
+            if (entry.isMeaningful()) {
+                size++;
+            }
+        }
+
+        return size;
+    }
+
+    public Iterator<IAEItemStack> iterator() {
+        return new MeaningfulItemIterator<>(this.getRecords().values());
+    }
+
+    private void putItemRecord(final IAEItemStack itemStack) {
+        this.getRecords().put(((AEItemStack) itemStack).getSharedStack(), itemStack);
+    }
+
+    abstract Map<AESharedItemStack, IAEItemStack> getRecords();
+
+    public abstract Collection<IAEItemStack> findFuzzy(final IAEItemStack filter, final FuzzyMode fuzzy);
+
+}

src/main/java/appeng/util/item/MeaningfulItemIterator.java

@@ -1,6 +1,6 @@
 /*
  * This file is part of Applied Energistics 2.
- * Copyright (c) 2013 - 2015, AlgorithmX2, All rights reserved.
+ * Copyright (c) 2021, TeamAppliedEnergistics, All rights reserved.
  *
  * Applied Energistics 2 is free software: you can redistribute it and/or modify
  * it under the terms of the GNU Lesser General Public License as published by
@@ -18,59 +18,53 @@
 
 package appeng.util.item;
 
-
+import java.util.Collection;
 import java.util.Iterator;
 import java.util.NoSuchElementException;
 
 import appeng.api.storage.data.IAEItemStack;
 
+/**
+ * This iterator will only return items from a collection that are meaningful (w.r.t.
+ * {@link IAEItemStack#isMeaningful()}. Items that are not meaningful are automatically removed from the collection as
+ * it is being iterated.
+ */
+public class MeaningfulItemIterator<T extends IAEItemStack> implements Iterator<T> {
+    private final Iterator<T> parent;
+    private T next;
 
-public class MeaningfulItemIterator<T extends IAEItemStack> implements Iterator<T>
-{
+    public MeaningfulItemIterator(final Collection<T> collection) {
+        this.parent = collection.iterator();
+        this.next = seekNext();
+    }
 
-	private final Iterator<T> parent;
-	private T next;
+    @Override
+    public boolean hasNext() {
+        return this.next != null;
+    }
 
-	public MeaningfulItemIterator( final Iterator<T> iterator )
-	{
-		this.parent = iterator;
-	}
+    @Override
+    public T next() {
+        if (this.next == null) {
+            throw new NoSuchElementException();
+        }
 
-	@Override
-	public boolean hasNext()
-	{
-		while( this.parent.hasNext() )
-		{
-			this.next = this.parent.next();
+        T result = this.next;
+        this.next = this.seekNext();
+        return result;
+    }
 
-			if( this.next.isMeaningful() )
-			{
-				return true;
-			}
-			else
-			{
-				this.parent.remove(); // self cleaning :3
-			}
-		}
+    private T seekNext() {
+        while (this.parent.hasNext()) {
+            T item = this.parent.next();
 
-		this.next = null;
-		return false;
-	}
+            if (item.isMeaningful()) {
+                return item;
+            } else {
+                this.parent.remove();
+            }
+        }
 
-	@Override
-	public T next()
-	{
-		if( this.next == null )
-		{
-			throw new NoSuchElementException();
-		}
-
-		return this.next;
-	}
-
-	@Override
-	public void remove()
-	{
-		this.parent.remove();
-	}
+        return null;
+    }
 }

src/main/java/appeng/util/item/NormalItemVariantList.java

@@ -0,0 +1,51 @@
+/*
+ * This file is part of Applied Energistics 2.
+ * Copyright (c) 2021, TeamAppliedEnergistics, All rights reserved.
+ *
+ * Applied Energistics 2 is free software: you can redistribute it and/or modify
+ * it under the terms of the GNU Lesser General Public License as published by
+ * the Free Software Foundation, either version 3 of the License, or
+ * (at your option) any later version.
+ *
+ * Applied Energistics 2 is distributed in the hope that it will be useful,
+ * but WITHOUT ANY WARRANTY; without even the implied warranty of
+ * MERCHANTABILITY or FITNESS FOR A PARTICULAR PURPOSE.  See the
+ * GNU Lesser General Public License for more details.
+ *
+ * You should have received a copy of the GNU Lesser General Public License
+ * along with Applied Energistics 2.  If not, see <http://www.gnu.org/licenses/lgpl>.
+ */
+
+package appeng.util.item;
+
+import java.util.Collection;
+import java.util.Map;
+
+import it.unimi.dsi.fastutil.objects.Reference2ObjectMap;
+import it.unimi.dsi.fastutil.objects.Reference2ObjectOpenHashMap;
+
+import appeng.api.config.FuzzyMode;
+import appeng.api.storage.data.IAEItemStack;
+
+/**
+ * This variant list is optimized for items that cannot be damaged and thus do not support querying durability ranges
+ * via {@link #findFuzzy(IAEItemStack, FuzzyMode)}.
+ */
+class NormalItemVariantList extends ItemVariantList {
+
+    private final Reference2ObjectMap<AESharedItemStack, IAEItemStack> records = new Reference2ObjectOpenHashMap<>();
+
+    @Override
+    Map<AESharedItemStack, IAEItemStack> getRecords() {
+        return this.records;
+    }
+
+    /**
+     * For items that do not support durability, we just return all variants to a fuzzy search.
+     */
+    @Override
+    public Collection<IAEItemStack> findFuzzy(IAEItemStack filter, FuzzyMode fuzzy) {
+        return this.getRecords().values();
+    }
+
+}