Metrics WIP

* Fixes #4253: Just transfer the recipe id instead of every ingredient.
* If possible handle any IRecipe for processing mode
* Improvements and support for AE2 facades.
* Switched to using JEI's displayed stacks (which means we can remove the shapeless variant).

Co-authored-by: Sebastian Hartte <sebastian@hartte.de>

gradle.properties

@@ -17,7 +17,7 @@ forge_version=33.0.42
 # Provided APIs                                         #
 #########################################################
 jei_minecraft_version=1.16.2
-jei_version=7.1.1.15
+jei_version=7.3.2.25
 top_version=3.0.3-beta-6
 hwyla_version=1.10.8-B72_1.15.2
 ctm_version=MC1.15.2-1.1.0.9

src/main/java/appeng/client/render/cablebus/CableBusBakedModel.java

@@ -18,6 +18,7 @@
 
 package appeng.client.render.cablebus;
 
+import java.lang.ref.WeakReference;
 import java.util.ArrayList;
 import java.util.Collections;
 import java.util.EnumMap;
@@ -51,12 +52,21 @@ import net.minecraftforge.client.model.data.IModelData;
 import appeng.api.parts.IPartModel;
 import appeng.api.util.AECableType;
 import appeng.api.util.AEColor;
+import appeng.metrics.Metrics;
 
 public class CableBusBakedModel implements IBakedModel {
 
     // The number of quads overall that will be cached
     private static final int CACHE_QUAD_COUNT = 5000;
 
+    // Keep a weak-ref to the last created cache for reporting metrics
+    private static WeakReference<LoadingCache<CableBusRenderState, List<BakedQuad>>> cacheForMetrics = new WeakReference<>(
+            null);
+
+    static {
+        Metrics.cache("cable_bus_model_cache", () -> cacheForMetrics.get());
+    }
+
     private final LoadingCache<CableBusRenderState, List<BakedQuad>> cableModelCache;
 
     private final CableBuilder cableBuilder;
@@ -74,6 +84,7 @@ public class CableBusBakedModel implements IBakedModel {
         this.partModels = partModels;
         this.particleTexture = particleTexture;
         this.cableModelCache = CacheBuilder.newBuilder()//
+                .recordStats()//
                 .maximumWeight(CACHE_QUAD_COUNT)//
                 .weigher((Weigher<CableBusRenderState, List<BakedQuad>>) (key, value) -> value.size())//
                 .build(new CacheLoader<CableBusRenderState, List<BakedQuad>>() {
@@ -84,6 +95,7 @@ public class CableBusBakedModel implements IBakedModel {
                         return model;
                     }
                 });
+        cacheForMetrics = new WeakReference<>(cableModelCache);
     }
 
     @Override

src/main/java/appeng/core/AEConfig.java

@@ -404,6 +404,10 @@ public final class AEConfig {
         return COMMON.improvedFluidMultiplier.get().floatValue();
     }
 
+    public int getPrometheusMetricsServerPort() {
+        return COMMON.prometheusMetricsServer.get();
+    }
+
     // Setters keep visibility as low as possible.
 
     private static class ClientConfig {
@@ -474,6 +478,7 @@ public final class AEConfig {
         public final BooleanValue removeCrashingItemsOnLoad;
         public final ConfigValue<Integer> formationPlaneEntityLimit;
         public final ConfigValue<Integer> craftingCalculationTimePerTick;
+        public final ConfigValue<Integer> prometheusMetricsServer;
 
         // Spatial IO/Dimension
         public final ConfigValue<Double> spatialPowerExponent;
@@ -558,6 +563,12 @@ public final class AEConfig {
                     .define("removeCrashingItemsOnLoad", false);
             builder.pop();
 
+            builder.push("metrics");
+            prometheusMetricsServer = builder.comment(
+                    "Enables the Prometheus Metrics exporting endpoint on 127.0.0.1 on this port number. 0 to disable.")
+                    .define("prometheusMetricsServer", 0);
+            builder.pop();
+
             builder.push("automation");
             formationPlaneEntityLimit = builder.comment("TODO").define("formationPlaneEntityLimit", 128);
             builder.pop();

src/main/java/appeng/core/AppEng.java

@@ -66,6 +66,7 @@ import appeng.entity.TinyTNTPrimedEntity;
 import appeng.entity.TinyTNTPrimedRenderer;
 import appeng.hooks.TickHandler;
 import appeng.integration.Integrations;
+import appeng.metrics.endpoint.PrometheusEndpoint;
 import appeng.parts.PartPlacement;
 import appeng.server.ServerHelper;
 
@@ -90,6 +91,8 @@ public final class AppEng {
         }
         INSTANCE = this;
 
+        startMetricsServer();
+
         ModLoadingContext.get().registerConfig(ModConfig.Type.CLIENT, AEConfig.CLIENT_SPEC);
         ModLoadingContext.get().registerConfig(ModConfig.Type.COMMON, AEConfig.COMMON_SPEC);
 
@@ -148,6 +151,20 @@ public final class AppEng {
         registerNetworkHandler();
 
         AddonLoader.loadAddons(Api.INSTANCE);
+
+        startMetricsServer();
+    }
+
+    private void startMetricsServer() {
+        int prometheusPort = AEConfig.instance().getPrometheusMetricsServerPort();
+        if (prometheusPort != 0) {
+            try {
+                AELog.info("Starting Prometheus Metrics Server on Port %s", prometheusPort);
+                new PrometheusEndpoint("localhost", prometheusPort);
+            } catch (Exception e) {
+                AELog.warn("Failed to start Prometheus Metrics-Server: %s", e);
+            }
+        }
     }
 
     @OnlyIn(Dist.CLIENT)

src/main/java/appeng/core/Registration.java

@@ -22,7 +22,6 @@ import java.util.function.Supplier;
 
 import net.minecraft.advancements.CriteriaTriggers;
 import net.minecraft.block.Block;
-import net.minecraft.block.BlockState;
 import net.minecraft.client.Minecraft;
 import net.minecraft.client.gui.ScreenManager;
 import net.minecraft.client.particle.ParticleManager;
@@ -33,17 +32,7 @@ import net.minecraft.item.crafting.IRecipeSerializer;
 import net.minecraft.particles.ParticleType;
 import net.minecraft.tileentity.TileEntityType;
 import net.minecraft.util.ResourceLocation;
-import net.minecraft.util.registry.Registry;
-import net.minecraft.util.registry.WorldGenRegistries;
 import net.minecraft.world.World;
-import net.minecraft.world.biome.Biome;
-import net.minecraft.world.gen.GenerationStage;
-import net.minecraft.world.gen.feature.Feature;
-import net.minecraft.world.gen.feature.IFeatureConfig;
-import net.minecraft.world.gen.feature.OreFeatureConfig;
-import net.minecraft.world.gen.feature.structure.Structure;
-import net.minecraft.world.gen.placement.IPlacementConfig;
-import net.minecraft.world.gen.placement.Placement;
 import net.minecraftforge.api.distmarker.Dist;
 import net.minecraftforge.api.distmarker.OnlyIn;
 import net.minecraftforge.client.event.ColorHandlerEvent;
@@ -62,14 +51,12 @@ import net.minecraftforge.fml.event.server.FMLServerStartingEvent;
 import net.minecraftforge.fml.javafmlmod.FMLJavaModLoadingContext;
 import net.minecraftforge.fml.loading.FMLEnvironment;
 import net.minecraftforge.fml.network.IContainerFactory;
-import net.minecraftforge.registries.ForgeRegistries;
 import net.minecraftforge.registries.IForgeRegistry;
 
 import appeng.api.config.Upgrades;
 import appeng.api.definitions.IBlocks;
 import appeng.api.definitions.IItems;
 import appeng.api.definitions.IParts;
-import appeng.api.features.AEFeature;
 import appeng.api.features.IRegistryContainer;
 import appeng.api.features.IWirelessTermHandler;
 import appeng.api.features.IWorldGen;
@@ -219,15 +206,8 @@ import appeng.recipes.game.FacadeRecipe;
 import appeng.recipes.handlers.GrinderRecipeSerializer;
 import appeng.recipes.handlers.InscriberRecipeSerializer;
 import appeng.server.AECommand;
-import appeng.spatial.SpatialStorageBiome;
-import appeng.spatial.SpatialStorageChunkGenerator;
-import appeng.spatial.SpatialStorageDimensionIds;
 import appeng.tile.AEBaseTileEntity;
 import appeng.tile.crafting.MolecularAssemblerRenderer;
-import appeng.worldgen.ChargedQuartzOreConfig;
-import appeng.worldgen.ChargedQuartzOreFeature;
-import appeng.worldgen.meteorite.MeteoriteStructure;
-import appeng.worldgen.meteorite.MeteoriteStructurePiece;
 
 final class Registration {
 

src/main/java/appeng/core/api/definitions/ApiItems.java

@@ -312,7 +312,7 @@ public final class ApiItems implements IItems {
 
         GrowingCrystalEntity.TYPE = registry
                 .<GrowingCrystalEntity>entity("growing_crystal", GrowingCrystalEntity::new, EntityClassification.MISC)
-                .customize(builder -> builder.size(0.25F, 0.25F)).build();
+                .customize(builder -> builder.size(0.25F, 0.4F)).build();
 
         // rv1
         this.encodedPattern = registry.item("encoded_pattern", EncodedPatternItem::new)

src/main/java/appeng/core/sync/packets/JEIRecipePacket.java

@@ -18,15 +18,27 @@
 
 package appeng.core.sync.packets;
 
+import java.util.Arrays;
+
+import javax.annotation.Nullable;
+
+import com.google.common.base.Preconditions;
+import com.mojang.datafixers.util.Pair;
+
 import io.netty.buffer.Unpooled;
 
 import net.minecraft.entity.player.PlayerEntity;
 import net.minecraft.entity.player.ServerPlayerEntity;
 import net.minecraft.inventory.container.Container;
 import net.minecraft.item.ItemStack;
-import net.minecraft.nbt.CompoundNBT;
-import net.minecraft.nbt.ListNBT;
+import net.minecraft.item.crafting.IRecipe;
+import net.minecraft.item.crafting.IRecipeSerializer;
+import net.minecraft.item.crafting.Ingredient;
+import net.minecraft.item.crafting.ShapedRecipe;
 import net.minecraft.network.PacketBuffer;
+import net.minecraft.util.NonNullList;
+import net.minecraft.util.ResourceLocation;
+import net.minecraftforge.common.crafting.IShapedRecipe;
 import net.minecraftforge.items.IItemHandler;
 
 import appeng.api.config.Actionable;
@@ -40,8 +52,10 @@ import appeng.api.networking.storage.IStorageGrid;
 import appeng.api.storage.IMEMonitor;
 import appeng.api.storage.channels.IItemStorageChannel;
 import appeng.api.storage.data.IAEItemStack;
+import appeng.container.implementations.PatternTermContainer;
 import appeng.core.Api;
 import appeng.core.sync.BasePacket;
+import appeng.core.sync.BasePacketHandler;
 import appeng.core.sync.network.INetworkInfo;
 import appeng.helpers.IContainerCraftingPacket;
 import appeng.items.storage.ViewCellItem;
@@ -54,152 +68,289 @@ import appeng.util.prioritylist.IPartitionList;
 
 public class JEIRecipePacket extends BasePacket {
 
-    private ItemStack[][] recipe;
+    /**
+     * Transmit only a recipe ID.
+     */
+    private static final int INLINE_RECIPE_NONE = 1;
+
+    /**
+     * Transmit the information about the recipe we actually need. This is
+     * explicitly limited since this is untrusted client->server info.
+     */
+    private static final int INLINE_RECIPE_SHAPED = 2;
+
+    private ResourceLocation recipeId;
+    /**
+     * This is optional, in case the client already knows it could not resolve the
+     * recipe id.
+     */
+    @Nullable
+    private IRecipe<?> recipe;
+    private boolean crafting;
 
     public JEIRecipePacket(final PacketBuffer stream) {
-        final CompoundNBT comp = stream.readCompoundTag();
-        if (comp != null) {
-            this.recipe = new ItemStack[9][];
-            for (int x = 0; x < this.recipe.length; x++) {
-                final ListNBT list = comp.getList("#" + x, 10);
-                if (list.size() > 0) {
-                    this.recipe[x] = new ItemStack[list.size()];
-                    for (int y = 0; y < list.size(); y++) {
-                        this.recipe[x][y] = ItemStack.read(list.getCompound(y));
-                    }
-                }
-            }
-        }
-    }
+        this.crafting = stream.readBoolean();
+        final String id = stream.readString(Short.MAX_VALUE);
+        this.recipeId = new ResourceLocation(id);
 
-    // api
-    public JEIRecipePacket(final CompoundNBT recipe) {
-        final PacketBuffer data = new PacketBuffer(Unpooled.buffer());
-
-        data.writeInt(this.getPacketID());
-
-        data.writeCompoundTag(recipe);
-
-        this.configureWrite(data);
-    }
-
-    @Override
-    public void serverPacketData(final INetworkInfo manager, final PlayerEntity player) {
-        final ServerPlayerEntity pmp = (ServerPlayerEntity) player;
-        final Container con = pmp.openContainer;
-
-        if (!(con instanceof IContainerCraftingPacket)) {
-            return;
-        }
-
-        final IContainerCraftingPacket cct = (IContainerCraftingPacket) con;
-        final IGridNode node = cct.getNetworkNode();
-
-        if (node == null) {
-            return;
-        }
-
-        final IGrid grid = node.getGrid();
-        if (grid == null) {
-            return;
-        }
-
-        final IStorageGrid inv = grid.getCache(IStorageGrid.class);
-        final IEnergyGrid energy = grid.getCache(IEnergyGrid.class);
-        final ISecurityGrid security = grid.getCache(ISecurityGrid.class);
-        final ICraftingGrid crafting = grid.getCache(ICraftingGrid.class);
-        final IItemHandler craftMatrix = cct.getInventoryByName("crafting");
-        final IItemHandler playerInventory = cct.getInventoryByName("player");
-
-        if (inv != null && this.recipe != null && security != null) {
-            final IMEMonitor<IAEItemStack> storage = inv
-                    .getInventory(Api.instance().storage().getStorageChannel(IItemStorageChannel.class));
-            final IPartitionList<IAEItemStack> filter = ViewCellItem.createFilter(cct.getViewCells());
-
-            for (int x = 0; x < craftMatrix.getSlots(); x++) {
-                ItemStack currentItem = craftMatrix.getStackInSlot(x);
-
-                // prepare slots
-                if (!currentItem.isEmpty()) {
-                    // already the correct item?
-                    ItemStack newItem = this.canUseInSlot(x, currentItem);
-
-                    // put away old item
-                    if (newItem != currentItem && security.hasPermission(player, SecurityPermissions.INJECT)) {
-                        final IAEItemStack in = AEItemStack.fromItemStack(currentItem);
-                        final IAEItemStack out = cct.useRealItems()
-                                ? Platform.poweredInsert(energy, storage, in, cct.getActionSource())
-                                : null;
-                        if (out != null) {
-                            currentItem = out.createItemStack();
-                        } else {
-                            currentItem = ItemStack.EMPTY;
-                        }
-                    }
-                }
-
-                if (currentItem.isEmpty() && this.recipe[x] != null) {
-                    // for each variant
-                    for (int y = 0; y < this.recipe[x].length && currentItem.isEmpty(); y++) {
-                        final IAEItemStack request = AEItemStack.fromItemStack(this.recipe[x][y]);
-                        if (request != null) {
-                            // try ae
-                            if ((filter == null || filter.isListed(request))
-                                    && security.hasPermission(player, SecurityPermissions.EXTRACT)) {
-                                request.setStackSize(1);
-                                IAEItemStack out;
-
-                                if (cct.useRealItems()) {
-                                    out = Platform.poweredExtraction(energy, storage, request, cct.getActionSource());
-                                } else {
-                                    // Query the crafting grid if there is a pattern providing the item
-                                    if (!crafting.getCraftingFor(request, null, 0, null).isEmpty()) {
-                                        out = request;
-                                    } else {
-                                        // Fall back using an existing item
-                                        out = storage.extractItems(request, Actionable.SIMULATE, cct.getActionSource());
-                                    }
-                                }
-
-                                if (out != null) {
-                                    currentItem = out.createItemStack();
-                                }
-                            }
-
-                            // try inventory
-                            if (currentItem.isEmpty()) {
-                                AdaptorItemHandler ad = new AdaptorItemHandler(playerInventory);
-
-                                if (cct.useRealItems()) {
-                                    currentItem = ad.removeItems(1, this.recipe[x][y], null);
-                                } else {
-                                    currentItem = ad.simulateRemove(1, this.recipe[x][y], null);
-                                }
-                            }
-                        }
-                    }
-                }
-                ItemHandlerUtil.setStackInSlot(craftMatrix, x, currentItem);
-            }
-            con.onCraftMatrixChanged(new WrapperInvItemHandler(craftMatrix));
+        int inlineRecipeType = stream.readVarInt();
+        switch (inlineRecipeType) {
+            case INLINE_RECIPE_NONE:
+                break;
+            case INLINE_RECIPE_SHAPED:
+                recipe = IRecipeSerializer.CRAFTING_SHAPED.read(this.recipeId, stream);
+                break;
+            default:
+                throw new IllegalArgumentException("Invalid inline recipe type.");
         }
     }
 
     /**
-     *
-     * @param slot
-     * @param is   itemstack
-     * @return is if it can be used, else EMPTY
+     * Sends a recipe identified by the given recipe ID to the server for either
+     * filling a crafting grid or a pattern.
      */
-    private ItemStack canUseInSlot(int slot, ItemStack is) {
-        if (this.recipe[slot] != null) {
-            for (ItemStack option : this.recipe[slot]) {
-                if (is.isItemEqual(option)) {
-                    return is;
+    public JEIRecipePacket(final ResourceLocation recipeId, final boolean crafting) {
+        PacketBuffer data = createCommonHeader(recipeId, crafting, INLINE_RECIPE_NONE);
+        this.configureWrite(data);
+    }
+
+    /**
+     * Sends a recipe to the server for either filling a crafting grid or a pattern.
+     * <p>
+     * Prefer the id-based constructor above whereever possible.
+     */
+    public JEIRecipePacket(final ShapedRecipe recipe, final boolean crafting) {
+        PacketBuffer data = createCommonHeader(recipe.getId(), crafting, INLINE_RECIPE_SHAPED);
+        IRecipeSerializer.CRAFTING_SHAPED.write(data, recipe);
+        this.configureWrite(data);
+    }
+
+    private PacketBuffer createCommonHeader(ResourceLocation recipeId, boolean crafting, int inlineRecipeType) {
+        final PacketBuffer data = new PacketBuffer(Unpooled.buffer());
+
+        data.writeInt(this.getPacketID());
+        data.writeBoolean(crafting);
+        data.writeResourceLocation(recipeId);
+        data.writeVarInt(inlineRecipeType);
+
+        return data;
+    }
+
+    /**
+     * Servside handler for this packet.
+     * <p>
+     * Makes use of {@link Preconditions#checkArgument(boolean)} as the
+     * {@link BasePacketHandler} is catching them and in general these cases should
+     * never happen except in an error case and should be logged then.
+     */
+    @Override
+    public void serverPacketData(final INetworkInfo manager, final PlayerEntity player) {
+        // Setup and verification
+        final ServerPlayerEntity pmp = (ServerPlayerEntity) player;
+        final Container con = pmp.openContainer;
+        Preconditions.checkArgument(con instanceof IContainerCraftingPacket);
+
+        IRecipe<?> recipe = player.getEntityWorld().getRecipeManager().getRecipe(this.recipeId).orElse(null);
+        if (recipe == null && this.recipe != null) {
+            // Certain recipes (i.e. AE2 facades) are represented in JEI as ShapedRecipe's,
+            // while in reality they
+            // are special recipes. Those recipes are sent across the wire...
+            recipe = this.recipe;
+        }
+        Preconditions.checkArgument(recipe != null);
+
+        final IContainerCraftingPacket cct = (IContainerCraftingPacket) con;
+        final IGridNode node = cct.getNetworkNode();
+
+        Preconditions.checkArgument(node != null);
+
+        final IGrid grid = node.getGrid();
+        Preconditions.checkArgument(grid != null);
+
+        final IStorageGrid inv = grid.getCache(IStorageGrid.class);
+        Preconditions.checkArgument(inv != null);
+
+        final ISecurityGrid security = grid.getCache(ISecurityGrid.class);
+        Preconditions.checkArgument(security != null);
+
+        final IEnergyGrid energy = grid.getCache(IEnergyGrid.class);
+        final ICraftingGrid crafting = grid.getCache(ICraftingGrid.class);
+        final IItemHandler craftMatrix = cct.getInventoryByName("crafting");
+        final IItemHandler playerInventory = cct.getInventoryByName("player");
+
+        final IMEMonitor<IAEItemStack> storage = inv
+                .getInventory(Api.instance().storage().getStorageChannel(IItemStorageChannel.class));
+        final IPartitionList<IAEItemStack> filter = ViewCellItem.createFilter(cct.getViewCells());
+        final NonNullList<Ingredient> ingredients = this.ensure3by3CraftingMatrix(recipe);
+
+        // Handle each slot
+        for (int x = 0; x < craftMatrix.getSlots(); x++) {
+            ItemStack currentItem = craftMatrix.getStackInSlot(x);
+            Ingredient ingredient = ingredients.get(x);
+
+            // prepare slots
+            if (!currentItem.isEmpty()) {
+                // already the correct item? True, skip everything else
+                ItemStack newItem = this.canUseInSlot(ingredient, currentItem);
+
+                // put away old item, if not correct
+                if (newItem != currentItem && security.hasPermission(player, SecurityPermissions.INJECT)) {
+                    final IAEItemStack in = AEItemStack.fromItemStack(currentItem);
+                    final IAEItemStack out = cct.useRealItems()
+                            ? Platform.poweredInsert(energy, storage, in, cct.getActionSource())
+                            : null;
+                    if (out != null) {
+                        currentItem = out.createItemStack();
+                    } else {
+                        currentItem = ItemStack.EMPTY;
+                    }
+                }
+            }
+
+            // Find item or pattern from the network
+            if (currentItem.isEmpty() && security.hasPermission(player, SecurityPermissions.EXTRACT)) {
+                IAEItemStack out;
+
+                if (cct.useRealItems()) {
+                    IAEItemStack request = findBestMatchingItemStack(ingredient, filter, storage, cct);
+                    out = request != null
+                            ? Platform.poweredExtraction(energy, storage, request.setStackSize(1),
+                                    cct.getActionSource())
+                            : null;
+                } else {
+                    out = findBestMatchingPattern(ingredient, filter, crafting, storage, cct);
+                    if (out == null) {
+                        out = findBestMatchingItemStack(ingredient, filter, storage, cct);
+                    }
+                    if (out == null && ingredient.getMatchingStacks().length > 0) {
+                        out = AEItemStack.fromItemStack(ingredient.getMatchingStacks()[0]);
+                    }
+                }
+
+                if (out != null) {
+                    currentItem = out.createItemStack();
+                }
+            }
+
+            // If still nothing, search the player inventory.
+            if (currentItem.isEmpty()) {
+                ItemStack[] matchingStacks = ingredient.getMatchingStacks();
+                for (ItemStack matchingStack : matchingStacks) {
+                    if (currentItem.isEmpty()) {
+                        AdaptorItemHandler ad = new AdaptorItemHandler(playerInventory);
+
+                        if (cct.useRealItems()) {
+                            currentItem = ad.removeItems(1, matchingStack, null);
+                        } else {
+                            currentItem = ad.simulateRemove(1, matchingStack, null);
+                        }
+                    }
+                }
+            }
+            ItemHandlerUtil.setStackInSlot(craftMatrix, x, currentItem);
+        }
+
+        if (!this.crafting) {
+            this.handleProcessing(con, cct, recipe);
+        }
+
+        con.onCraftMatrixChanged(new WrapperInvItemHandler(craftMatrix));
+    }
+
+    /**
+     * Expand any recipe to a 3x3 matrix.
+     * <p>
+     * Will throw an {@link IllegalArgumentException} in case it has more than 9 or
+     * a shaped recipe is either wider or higher than 3. ingredients.
+     */
+    private NonNullList<Ingredient> ensure3by3CraftingMatrix(IRecipe<?> recipe) {
+        NonNullList<Ingredient> ingredients = recipe.getIngredients();
+        NonNullList<Ingredient> expandedIngredients = NonNullList.withSize(9, Ingredient.EMPTY);
+
+        Preconditions.checkArgument(ingredients.size() <= 9);
+
+        // shaped recipes can be smaller than 3x3, expand to 3x3 to match the crafting
+        // matrix
+        if (recipe instanceof IShapedRecipe) {
+            IShapedRecipe<?> shapedRecipe = (IShapedRecipe<?>) recipe;
+            int width = shapedRecipe.getRecipeWidth();
+            int height = shapedRecipe.getRecipeHeight();
+            Preconditions.checkArgument(width <= 3 && height <= 3);
+
+            for (int h = 0; h < height; h++) {
+                for (int w = 0; w < width; w++) {
+                    int source = w + h * width;
+                    int target = w + h * 3;
+                    Ingredient i = ingredients.get(source);
+                    expandedIngredients.set(target, i);
                 }
             }
         }
-        return ItemStack.EMPTY;
+        // Anything else should be a flat list
+        else {
+            for (int i = 0; i < ingredients.size(); i++) {
+                expandedIngredients.set(i, ingredients.get(i));
+            }
+        }
+
+        return expandedIngredients;
+    }
+
+    /**
+     * @param is itemstack
+     * @return is if it can be used, else EMPTY
+     */
+    private ItemStack canUseInSlot(Ingredient ingredient, ItemStack is) {
+        return Arrays.stream(ingredient.getMatchingStacks()).filter(p -> p.isItemEqual(is)).findFirst()
+                .orElse(ItemStack.EMPTY);
+    }
+
+    /**
+     * Finds the first matching itemstack with the highest stored amount.
+     */
+    private IAEItemStack findBestMatchingItemStack(Ingredient ingredients, IPartitionList<IAEItemStack> filter,
+            IMEMonitor<IAEItemStack> storage, IContainerCraftingPacket cct) {
+        return Arrays.stream(ingredients.getMatchingStacks()).map(AEItemStack::fromItemStack) //
+                .filter(r -> r != null && (filter == null || filter.isListed(r))) //
+                .map(s -> {
+                    // Determine the stored count
+                    IAEItemStack stored = storage.extractItems(s.copy().setStackSize(Long.MAX_VALUE),
+                            Actionable.SIMULATE, cct.getActionSource());
+                    return Pair.of(s, stored != null ? stored.getStackSize() : 0);
+                }).min((left, right) -> Long.compare(right.getSecond(), left.getSecond()))//
+                .map(Pair::getFirst).orElse(null);
+    }
+
+    /**
+     * This tries to find the first pattern matching the list of ingredients.
+     * <p>
+     * As additional condition, it sorts by the stored amount to return the one with
+     * the highest stored amount.
+     */
+    private IAEItemStack findBestMatchingPattern(Ingredient ingredients, IPartitionList<IAEItemStack> filter,
+            ICraftingGrid crafting, IMEMonitor<IAEItemStack> storage, IContainerCraftingPacket cct) {
+        return Arrays.stream(ingredients.getMatchingStacks()).map(AEItemStack::fromItemStack)
+                .filter(r -> r != null && (filter == null || filter.isListed(r)))
+                .map(s -> s.setCraftable(!crafting.getCraftingFor(s, null, 0, null).isEmpty()))
+                .filter(IAEItemStack::isCraftable).map(s -> {
+                    final IAEItemStack stored = storage.extractItems(s, Actionable.SIMULATE, cct.getActionSource());
+                    return s.setStackSize(stored != null ? stored.getStackSize() : 0);
+                }).min((left, right) -> {
+                    final int craftable = Boolean.compare(left.isCraftable(), right.isCraftable());
+                    return craftable != 0 ? craftable : Long.compare(right.getStackSize(), left.getStackSize());
+                }).orElse(null);
+    }
+
+    private void handleProcessing(Container con, IContainerCraftingPacket cct, IRecipe<?> recipe) {
+        if (con instanceof PatternTermContainer) {
+            PatternTermContainer patternTerm = (PatternTermContainer) con;
+            if (!patternTerm.craftingMode) {
+                final IItemHandler output = cct.getInventoryByName("output");
+                ItemHandlerUtil.setStackInSlot(output, 0, recipe.getRecipeOutput());
+                ItemHandlerUtil.setStackInSlot(output, 1, ItemStack.EMPTY);
+                ItemHandlerUtil.setStackInSlot(output, 2, ItemStack.EMPTY);
+            }
+        }
     }
 
 }

src/main/java/appeng/core/sync/packets/MEInventoryUpdatePacket.java

@@ -19,11 +19,9 @@
 package appeng.core.sync.packets;
 
 import java.io.IOException;
-import java.io.OutputStream;
 import java.nio.BufferOverflowException;
 import java.util.ArrayList;
 import java.util.List;
-import java.util.zip.GZIPOutputStream;
 
 import javax.annotation.Nullable;
 

src/main/java/appeng/core/worlddata/StorageData.java

@@ -157,4 +157,8 @@ final class StorageData extends WorldSavedData implements IWorldGridStorageData
         return tag;
     }
 
+    public int size() {
+        return storage.size();
+    }
+
 }

src/main/java/appeng/core/worlddata/WorldData.java

@@ -28,12 +28,13 @@ import com.google.common.base.Preconditions;
 import net.minecraft.server.MinecraftServer;
 import net.minecraft.world.server.ServerWorld;
 
+import appeng.metrics.Metrics;
 import appeng.services.CompassService;
 import appeng.services.compass.CompassThreadFactory;
 
 /**
  * Singleton access to anything related to world-based data.
- *
+ * <p>
  * Data will change depending which world is loaded. Will probably not affect
  * SMP at all since only one world is loaded, but SSP more, cause they play on
  * different worlds.
@@ -53,8 +54,15 @@ public final class WorldData implements IWorldData {
     @Nullable
     private static MinecraftServer server;
 
+    static {
+        Metrics.gauge("grid_storage_count", () -> {
+            WorldData worldData = (WorldData) instance;
+            return worldData != null ? worldData.storageData.size() : 0;
+        });
+    }
+
     private final IWorldPlayerData playerData;
-    private final IWorldGridStorageData storageData;
+    private final StorageData storageData;
     private final IWorldCompassData compassData;
 
     private WorldData(@Nonnull final ServerWorld overworld) {
@@ -80,7 +88,6 @@ public final class WorldData implements IWorldData {
 
     /**
      * @return ae2 data related to a specific world
-     *
      * @deprecated do not use singletons which are dependent on specific world state
      */
     @Deprecated
@@ -102,7 +109,7 @@ public final class WorldData implements IWorldData {
 
     /**
      * Requires to start up from external from here
-     *
+     * <p>
      * drawback of the singleton build style
      */
     public static void onServerStarting(MinecraftServer server) {

src/main/java/appeng/entity/TinyTNTPrimedEntity.java

@@ -40,7 +40,6 @@ import net.minecraft.util.SoundEvents;
 import net.minecraft.util.math.AxisAlignedBB;
 import net.minecraft.util.math.BlockPos;
 import net.minecraft.world.Explosion;
-import net.minecraft.world.Explosion.Mode;
 import net.minecraft.world.World;
 import net.minecraftforge.fml.common.registry.IEntityAdditionalSpawnData;
 import net.minecraftforge.fml.network.NetworkHooks;

src/main/java/appeng/fluids/client/gui/widgets/FluidSlotWidget.java

@@ -15,7 +15,6 @@ import net.minecraft.item.ItemStack;
 import net.minecraft.util.text.ITextComponent;
 import net.minecraft.util.text.StringTextComponent;
 import net.minecraft.util.text.TranslationTextComponent;
-import net.minecraftforge.common.util.LazyOptional;
 import net.minecraftforge.fluids.FluidAttributes;
 import net.minecraftforge.fluids.FluidStack;
 import net.minecraftforge.fluids.FluidUtil;

src/main/java/appeng/fluids/container/FluidConfigurableContainer.java

@@ -9,7 +9,6 @@ import net.minecraft.entity.player.PlayerInventory;
 import net.minecraft.inventory.container.ContainerType;
 import net.minecraft.inventory.container.IContainerListener;
 import net.minecraft.item.ItemStack;
-import net.minecraftforge.common.util.LazyOptional;
 import net.minecraftforge.fluids.FluidStack;
 import net.minecraftforge.fluids.FluidUtil;
 

src/main/java/appeng/hooks/TickHandler.java

@@ -57,6 +57,7 @@ import appeng.core.AppEng;
 import appeng.core.sync.packets.PaintedEntityPacket;
 import appeng.crafting.CraftingJob;
 import appeng.me.Grid;
+import appeng.metrics.Metrics;
 import appeng.tile.AEBaseTileEntity;
 import appeng.util.IWorldCallable;
 import appeng.util.Platform;
@@ -77,6 +78,11 @@ public class TickHandler {
         return INSTANCE;
     }
 
+    static {
+        Metrics.gauge("ticking_network_count", () -> INSTANCE.server.networks.size());
+        Metrics.gauge("crafting_job_count", INSTANCE.craftingJobs::size);
+    }
+
     public static void setup(IEventBus eventBus) {
         eventBus.addListener(INSTANCE::onServerTick);
         eventBus.addListener(INSTANCE::onWorldTick);

src/main/java/appeng/integration/abstraction/IJEI.java

@@ -18,6 +18,8 @@
 
 package appeng.integration.abstraction;
 
+import mezz.jei.api.runtime.IJeiRuntime;
+
 import appeng.integration.IIntegrationModule;
 
 /**
@@ -25,6 +27,10 @@ import appeng.integration.IIntegrationModule;
  */
 public interface IJEI extends IIntegrationModule {
 
+    default IJeiRuntime getRuntime() {
+        return null;
+    }
+
     default String getSearchText() {
         return "";
     }

src/main/java/appeng/integration/modules/jei/CraftingRecipeTransferHandler.java

@@ -0,0 +1,47 @@
+/*
+ * This file is part of Applied Energistics 2.
+ * Copyright (c) 2020 Team Appliedenergistics, 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.integration.modules.jei;
+
+import net.minecraft.entity.player.PlayerEntity;
+import net.minecraft.item.crafting.IRecipe;
+
+import mezz.jei.api.gui.IRecipeLayout;
+import mezz.jei.api.recipe.transfer.IRecipeTransferError;
+import mezz.jei.api.recipe.transfer.IRecipeTransferHandlerHelper;
+
+import appeng.container.implementations.CraftingTermContainer;
+
+public class CraftingRecipeTransferHandler extends RecipeTransferHandler<CraftingTermContainer> {
+
+    CraftingRecipeTransferHandler(Class<CraftingTermContainer> containerClass, IRecipeTransferHandlerHelper helper) {
+        super(containerClass, helper);
+    }
+
+    @Override
+    protected IRecipeTransferError doTransferRecipe(CraftingTermContainer container, IRecipe<?> recipe,
+            IRecipeLayout recipeLayout, PlayerEntity player, boolean maxTransfer) {
+        return null;
+    }
+
+    @Override
+    protected boolean isCrafting() {
+        return true;
+    }
+
+}

src/main/java/appeng/integration/modules/jei/FacadeRegistryPlugin.java

@@ -111,6 +111,8 @@ class FacadeRegistryPlugin implements IRecipeManagerPlugin {
         ingredients.set(7, Ingredient.fromStacks(cableAnchor));
         ingredients.set(4, Ingredient.fromStacks(textureItem));
 
+        result.setCount(4);
+
         return new ShapedRecipe(id, "", 3, 3, ingredients, result);
     }
 

src/main/java/appeng/integration/modules/jei/JEIPlugin.java

@@ -82,11 +82,15 @@ public class JEIPlugin implements IModPlugin {
 
     @Override
     public void registerRecipeTransferHandlers(IRecipeTransferRegistration registration) {
-        // Allow recipe transfer from JEI to crafting and pattern terminal
-        registration.addRecipeTransferHandler(new RecipeTransferHandler<>(CraftingTermContainer.class),
-                VanillaRecipeCategoryUid.CRAFTING);
-        registration.addRecipeTransferHandler(new RecipeTransferHandler<>(PatternTermContainer.class),
+
+        // Allow vanilla crafting recipe transfer from JEI to crafting terminal
+        registration.addRecipeTransferHandler(
+                new CraftingRecipeTransferHandler(CraftingTermContainer.class, registration.getTransferHelper()),
                 VanillaRecipeCategoryUid.CRAFTING);
+
+        // Universal handler for processing to try and handle all IRecipe
+        registration.addUniversalRecipeTransferHandler(
+                new PatternRecipeTransferHandler(PatternTermContainer.class, registration.getTransferHelper()));
     }
 
     @Override

src/main/java/appeng/integration/modules/jei/JeiRuntimeAdapter.java

@@ -37,6 +37,10 @@ class JeiRuntimeAdapter implements IJEI {
         return true;
     }
 
+    public IJeiRuntime getRuntime() {
+        return runtime;
+    }
+
     @Override
     public String getSearchText() {
         return Strings.nullToEmpty(this.runtime.getIngredientFilter().getFilterText());

src/main/java/appeng/integration/modules/jei/PatternRecipeTransferHandler.java

@@ -0,0 +1,58 @@
+/*
+ * This file is part of Applied Energistics 2.
+ * Copyright (c) 2020 Team Appliedenergistics, 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.integration.modules.jei;
+
+import net.minecraft.client.resources.I18n;
+import net.minecraft.entity.player.PlayerEntity;
+import net.minecraft.item.crafting.IRecipe;
+
+import mezz.jei.api.constants.VanillaRecipeCategoryUid;
+import mezz.jei.api.gui.IRecipeLayout;
+import mezz.jei.api.recipe.transfer.IRecipeTransferError;
+import mezz.jei.api.recipe.transfer.IRecipeTransferHandlerHelper;
+
+import appeng.container.implementations.PatternTermContainer;
+
+public class PatternRecipeTransferHandler extends RecipeTransferHandler<PatternTermContainer> {
+
+    PatternRecipeTransferHandler(Class<PatternTermContainer> containerClass, IRecipeTransferHandlerHelper helper) {
+        super(containerClass, helper);
+    }
+
+    protected IRecipeTransferError doTransferRecipe(PatternTermContainer container, IRecipe<?> recipe,
+            IRecipeLayout recipeLayout, PlayerEntity player, boolean maxTransfer) {
+        if (container.isCraftingMode()
+                && recipeLayout.getRecipeCategory().getUid() != VanillaRecipeCategoryUid.CRAFTING) {
+            return this.helper
+                    .createUserErrorWithTooltip(I18n.format("jei.appliedenergistics2.requires_processing_mode"));
+        }
+
+        if (recipe.getRecipeOutput().isEmpty()) {
+            return this.helper.createUserErrorWithTooltip(I18n.format("jei.appliedenergistics2.no_output"));
+        }
+
+        return null;
+    }
+
+    @Override
+    protected boolean isCrafting() {
+        return false;
+    }
+
+}

src/main/java/appeng/integration/modules/jei/RecipeTransferHandler.java

@@ -18,101 +18,128 @@
 
 package appeng.integration.modules.jei;
 
-import java.util.ArrayList;
-import java.util.List;
 import java.util.Map;
 
-import javax.annotation.Nullable;
-
+import net.minecraft.client.resources.I18n;
 import net.minecraft.entity.player.PlayerEntity;
 import net.minecraft.inventory.container.Container;
-import net.minecraft.inventory.container.Slot;
 import net.minecraft.item.ItemStack;
-import net.minecraft.nbt.CompoundNBT;
-import net.minecraft.nbt.ListNBT;
+import net.minecraft.item.crafting.IRecipe;
+import net.minecraft.item.crafting.Ingredient;
+import net.minecraft.item.crafting.ShapedRecipe;
+import net.minecraft.item.crafting.ShapelessRecipe;
+import net.minecraft.util.NonNullList;
+import net.minecraft.util.ResourceLocation;
 
 import mezz.jei.api.gui.IRecipeLayout;
 import mezz.jei.api.gui.ingredient.IGuiIngredient;
 import mezz.jei.api.recipe.transfer.IRecipeTransferError;
 import mezz.jei.api.recipe.transfer.IRecipeTransferHandler;
+import mezz.jei.api.recipe.transfer.IRecipeTransferHandlerHelper;
 
-import appeng.container.slot.CraftingMatrixSlot;
-import appeng.container.slot.FakeCraftingMatrixSlot;
 import appeng.core.sync.network.NetworkHandler;
 import appeng.core.sync.packets.JEIRecipePacket;
-import appeng.util.Platform;
+import appeng.helpers.IContainerCraftingPacket;
 
-class RecipeTransferHandler<T extends Container> implements IRecipeTransferHandler<T> {
+abstract class RecipeTransferHandler<T extends Container & IContainerCraftingPacket>
+        implements IRecipeTransferHandler<T> {
 
     private final Class<T> containerClass;
+    protected final IRecipeTransferHandlerHelper helper;
 
-    RecipeTransferHandler(Class<T> containerClass) {
+    RecipeTransferHandler(Class<T> containerClass, IRecipeTransferHandlerHelper helper) {
         this.containerClass = containerClass;
+        this.helper = helper;
     }
 
     @Override
-    public Class<T> getContainerClass() {
+    public final Class<T> getContainerClass() {
         return this.containerClass;
     }
 
-    @Nullable
     @Override
-    public IRecipeTransferError transferRecipe(T container, IRecipeLayout recipeLayout, PlayerEntity player,
-            boolean maxTransfer, boolean doTransfer) {
-        if (!doTransfer) {
-            return null;
+    public final IRecipeTransferError transferRecipe(T container, Object recipe, IRecipeLayout recipeLayout,
+            PlayerEntity player, boolean maxTransfer, boolean doTransfer) {
+        if (!(recipe instanceof IRecipe)) {
+            return this.helper.createInternalError();
+        }
+        final IRecipe<?> irecipe = (IRecipe<?>) recipe;
+        final ResourceLocation recipeId = irecipe.getId();
+
+        if (recipeId == null) {
+            return this.helper.createUserErrorWithTooltip(I18n.format("jei.appliedenergistics2.missing_id"));
         }
 
-        Map<Integer, ? extends IGuiIngredient<ItemStack>> ingredients = recipeLayout.getItemStacks()
-                .getGuiIngredients();
-
-        final CompoundNBT recipe = new CompoundNBT();
-
-        int slotIndex = 0;
-        for (Map.Entry<Integer, ? extends IGuiIngredient<ItemStack>> ingredientEntry : ingredients.entrySet()) {
-            IGuiIngredient<ItemStack> ingredient = ingredientEntry.getValue();
-            if (!ingredient.isInput()) {
-                continue;
+        // Check that the recipe can actually be looked up via the manager, i.e. our
+        // facade recipes
+        // have an ID, but are never registered with the recipe manager.
+        boolean canSendReference = true;
+        if (!player.getEntityWorld().getRecipeManager().getRecipe(recipeId).isPresent()) {
+            // Validate that the recipe is a shapeless or shapedrecipe, since we can
+            // serialize those
+            if (!(recipe instanceof ShapedRecipe) && !(recipe instanceof ShapelessRecipe)) {
+                return this.helper.createUserErrorWithTooltip(I18n.format("jei.appliedenergistics2.missing_id"));
             }
+            canSendReference = false;
+        }
 
-            for (final Slot slot : container.inventorySlots) {
-                if (slot instanceof CraftingMatrixSlot || slot instanceof FakeCraftingMatrixSlot) {
-                    if (slot.getSlotIndex() == slotIndex) {
-                        final ListNBT tags = new ListNBT();
-                        final List<ItemStack> list = new ArrayList<>();
-                        final ItemStack displayed = ingredient.getDisplayedIngredient();
+        if (!irecipe.canFit(3, 3)) {
+            return this.helper.createUserErrorWithTooltip(I18n.format("jei.appliedenergistics2.recipe_too_large"));
+        }
 
-                        // prefer currently displayed item
-                        if (displayed != null && !displayed.isEmpty()) {
-                            list.add(displayed);
+        final IRecipeTransferError error = doTransferRecipe(container, irecipe, recipeLayout, player, maxTransfer);
+
+        if (error != null) {
+            return error;
+        }
+
+        if (doTransfer) {
+            if (canSendReference) {
+                NetworkHandler.instance().sendToServer(new JEIRecipePacket(recipeId, isCrafting()));
+            } else {
+                // To avoid earlier problems of too large packets being sent that crashed the
+                // client,
+                // as a fallback when the recipe ID could not be resolved, we'll just send the
+                // displayed
+                // items.
+                NonNullList<Ingredient> flatIngredients = NonNullList.withSize(9, Ingredient.EMPTY);
+                ItemStack output = ItemStack.EMPTY;
+
+                // Determine the first JEI slot that has an actual input, we'll use this to
+                // offset the
+                // crafting grid target slot
+                int firstInputSlot = recipeLayout.getItemStacks().getGuiIngredients().entrySet().stream()
+                        .filter(e -> e.getValue().isInput()).mapToInt(Map.Entry::getKey).min().orElse(0);
+
+                // Now map the actual ingredients into the output/input
+                for (Map.Entry<Integer, ? extends IGuiIngredient<ItemStack>> entry : recipeLayout.getItemStacks()
+                        .getGuiIngredients().entrySet()) {
+                    IGuiIngredient<ItemStack> item = entry.getValue();
+                    if (item.getDisplayedIngredient() == null) {
+                        continue;
+                    }
+
+                    int inputIndex = entry.getKey() - firstInputSlot;
+                    if (item.isInput() && inputIndex < flatIngredients.size()) {
+                        ItemStack displayedIngredient = item.getDisplayedIngredient();
+                        if (displayedIngredient != null) {
+                            flatIngredients.set(inputIndex, Ingredient.fromStacks(displayedIngredient));
                         }
-
-                        // prefer pure crystals.
-                        for (ItemStack stack : ingredient.getAllIngredients()) {
-                            if (Platform.isRecipePrioritized(stack)) {
-                                list.add(0, stack);
-                            } else {
-                                list.add(stack);
-                            }
-                        }
-
-                        for (final ItemStack is : list) {
-                            final CompoundNBT tag = new CompoundNBT();
-                            is.write(tag);
-                            tags.add(tag);
-                        }
-
-                        recipe.put("#" + slot.getSlotIndex(), tags);
-                        break;
+                    } else if (!item.isInput() && output.isEmpty()) {
+                        output = item.getDisplayedIngredient();
                     }
                 }
+
+                ShapedRecipe fallbackRecipe = new ShapedRecipe(recipeId, "", 3, 3, flatIngredients, output);
+                NetworkHandler.instance().sendToServer(new JEIRecipePacket(fallbackRecipe, isCrafting()));
             }
-
-            slotIndex++;
         }
 
-        NetworkHandler.instance().sendToServer(new JEIRecipePacket(recipe));
-
         return null;
     }
+
+    protected abstract IRecipeTransferError doTransferRecipe(T container, IRecipe<?> recipe, IRecipeLayout recipeLayout,
+            PlayerEntity player, boolean maxTransfer);
+
+    protected abstract boolean isCrafting();
 }

src/main/java/appeng/metrics/CacheMetrics.java

@@ -0,0 +1,54 @@
+package appeng.metrics;
+
+import java.util.function.Supplier;
+
+import com.google.common.cache.Cache;
+import com.google.common.cache.CacheStats;
+
+/**
+ * Cache Metrics simplify reporting of metrics for a Guava {@link Cache}.
+ */
+public class CacheMetrics extends Metric {
+
+    private final Supplier<Cache<?, ?>> cacheSupplier;
+
+    // Pre-allocate these to avoid repeated concatenation during reporting
+    private final String sizeId;
+    private final String hitCountId;
+    private final String missCountId;
+    private final String loadSuccessCountId;
+    private final String loadExceptionCountId;
+    private final String totalLoadTimeId;
+    private final String evictionCountId;
+
+    public CacheMetrics(String id, Supplier<Cache<?, ?>> cacheSupplier) {
+        super(id);
+        this.cacheSupplier = cacheSupplier;
+
+        this.sizeId = id + ".size";
+        this.hitCountId = id + ".hit-count";
+        this.missCountId = id + ".miss-count";
+        this.loadSuccessCountId = id + ".load-success-count";
+        this.loadExceptionCountId = id + ".load-exception-count";
+        this.totalLoadTimeId = id + ".total-load-time";
+        this.evictionCountId = id + ".eviction-count";
+    }
+
+    @Override
+    public void accept(MetricVisitor visitor) {
+        Cache<?, ?> cache = this.cacheSupplier.get();
+
+        if (cache != null) {
+            visitor.visitGauge(sizeId, cache.size()); // Thread-safe
+
+            CacheStats stats = cache.stats(); // Thread-safe
+            visitor.visitGauge(hitCountId, stats.hitCount());
+            visitor.visitGauge(missCountId, stats.missCount());
+            visitor.visitGauge(loadSuccessCountId, stats.loadSuccessCount());
+            visitor.visitGauge(loadExceptionCountId, stats.loadExceptionCount());
+            visitor.visitGauge(totalLoadTimeId, stats.totalLoadTime());
+            visitor.visitGauge(evictionCountId, stats.evictionCount());
+        }
+    }
+
+}

src/main/java/appeng/metrics/Gauge.java

@@ -0,0 +1,31 @@
+package appeng.metrics;
+
+import java.util.function.Supplier;
+
+/**
+ * A Gauge is a Metric that will simply read the current value of something when
+ * the metrics are being reported.
+ */
+class Gauge extends Metric {
+
+    private final Supplier<Number> valueSupplier;
+
+    public Gauge(String id, Supplier<Number> valueSupplier) {
+        super(id);
+        this.valueSupplier = valueSupplier;
+    }
+
+    public Supplier<Number> getValueSupplier() {
+        return valueSupplier;
+    }
+
+    public Number getValue() {
+        return valueSupplier.get();
+    }
+
+    @Override
+    public void accept(MetricVisitor visitor) {
+        visitor.visitGauge(getId(), getValue());
+    }
+
+}

src/main/java/appeng/metrics/Metric.java

@@ -0,0 +1,34 @@
+package appeng.metrics;
+
+import java.util.Objects;
+
+abstract class Metric {
+
+    private final String id;
+
+    public Metric(String id) {
+        this.id = Objects.requireNonNull(id);
+    }
+
+    public String getId() {
+        return id;
+    }
+
+    @Override
+    public boolean equals(Object o) {
+        if (this == o)
+            return true;
+        if (o == null || getClass() != o.getClass())
+            return false;
+        Metric metric = (Metric) o;
+        return id.equals(metric.id);
+    }
+
+    @Override
+    public int hashCode() {
+        return Objects.hash(id);
+    }
+
+    public abstract void accept(MetricVisitor visitor);
+
+}

src/main/java/appeng/metrics/MetricVisitor.java

@@ -0,0 +1,7 @@
+package appeng.metrics;
+
+public interface MetricVisitor {
+
+    void visitGauge(String id, Number value);
+
+}

src/main/java/appeng/metrics/Metrics.java

@@ -0,0 +1,51 @@
+package appeng.metrics;
+
+import java.util.ArrayList;
+import java.util.List;
+import java.util.function.LongSupplier;
+import java.util.function.Supplier;
+
+import com.google.common.base.Suppliers;
+import com.google.common.cache.Cache;
+import com.google.common.cache.CacheStats;
+
+/**
+ * Registry to register Metrics.
+ */
+public final class Metrics {
+
+    private static final List<Metric> metrics = new ArrayList<>();
+
+    private Metrics() {
+    }
+
+    /**
+     * Registers a Gauge, which is a simple metric with no state that will be
+     * queried for its current value whenever metrics are being reported.
+     */
+    public static synchronized void gauge(String id, Supplier<Number> valueSupplier) {
+        metrics.add(new Gauge(id, valueSupplier));
+    }
+
+    /**
+     * Register several standard metrics for a Guava {@link Cache}.
+     */
+    public static synchronized void cache(String name, Cache<?, ?> cache) {
+        metrics.add(new CacheMetrics(name, () -> cache));
+    }
+
+    /**
+     * Register several standard metrics for a Guava {@link Cache} based on a
+     * supplier to support an underlying changing cache.
+     */
+    public static synchronized void cache(String name, Supplier<Cache<?, ?>> cacheSupplier) {
+        metrics.add(new CacheMetrics(name, cacheSupplier));
+    }
+
+    public static synchronized void visit(MetricVisitor visitor) {
+        for (Metric metric : metrics) {
+            metric.accept(visitor);
+        }
+    }
+
+}

src/main/java/appeng/metrics/endpoint/PrometheusEndpoint.java

@@ -0,0 +1,78 @@
+package appeng.metrics.endpoint;
+
+import java.io.IOException;
+import java.io.OutputStreamWriter;
+import java.io.Writer;
+import java.net.InetAddress;
+import java.net.InetSocketAddress;
+import java.nio.charset.StandardCharsets;
+
+import com.sun.net.httpserver.HttpExchange;
+import com.sun.net.httpserver.HttpServer;
+
+import appeng.metrics.Metrics;
+import appeng.metrics.reporter.PrometheusReporter;
+
+/**
+ * Starts an embedded HTTP-Server that will expose the Metrics in a format
+ * compatible with Prometheus.
+ */
+public class PrometheusEndpoint implements AutoCloseable {
+
+    private final HttpServer server;
+
+    private final PrometheusReporter reporter = new PrometheusReporter();
+
+    public PrometheusEndpoint(String hostname, int port) {
+        try {
+            this.server = HttpServer.create();
+        } catch (IOException e) {
+            throw new RuntimeException("Failed to create metrics HTTP-server", e);
+        }
+
+        InetSocketAddress address;
+        if (hostname.isEmpty()) {
+            address = new InetSocketAddress((InetAddress) null, port);
+        } else {
+            address = new InetSocketAddress(hostname, port);
+        }
+
+        // Default endpoint is /metrics in Prometheus
+        this.server.createContext("/metrics", this::handler);
+
+        try {
+            this.server.bind(address, 0);
+        } catch (IOException e) {
+            throw new RuntimeException("Failed to bind metrics HTTP server to " + address, e);
+        }
+
+        this.server.start();
+
+    }
+
+    @Override
+    public void close() {
+        this.server.stop(0);
+    }
+
+    private synchronized void handler(HttpExchange exchange) throws IOException {
+        // Update metrics
+        reporter.reset();
+        Metrics.visit(reporter);
+
+        CharSequence report = getReport();
+
+        exchange.getResponseHeaders().add("Content-Type", "text/plain; version=0.0.4");
+        exchange.sendResponseHeaders(200, report.length());
+
+        try (Writer writer = new OutputStreamWriter(exchange.getResponseBody(), StandardCharsets.US_ASCII)) {
+            writer.append(report);
+        }
+        exchange.close();
+    }
+
+    private CharSequence getReport() {
+        return reporter.getReport();
+    }
+
+}

src/main/java/appeng/metrics/reporter/PrintStreamReporter.java

@@ -0,0 +1,24 @@
+package appeng.metrics.reporter;
+
+import java.io.PrintStream;
+
+import appeng.metrics.MetricVisitor;
+
+/**
+ * Reports Metrics as simple key-value pairs to a {@link PrintStream} (i.e.
+ * {@link System#out}).
+ */
+public class PrintStreamReporter implements MetricVisitor {
+
+    private final PrintStream out;
+
+    public PrintStreamReporter(PrintStream out) {
+        this.out = out;
+    }
+
+    @Override
+    public void visitGauge(String id, Number value) {
+        out.println(id + '=' + value);
+    }
+
+}

src/main/java/appeng/metrics/reporter/PrometheusReporter.java

@@ -0,0 +1,54 @@
+package appeng.metrics.reporter;
+
+import appeng.metrics.MetricVisitor;
+
+/**
+ * Reports the metrics in a format compatible with Prometheus.
+ * <p>
+ * See <a href=
+ * "https://prometheus.io/docs/instrumenting/exposition_formats/">Prometheus
+ * Docs</a>
+ */
+public class PrometheusReporter implements MetricVisitor {
+
+    private final StringBuilder response = new StringBuilder();
+
+    @Override
+    public void visitGauge(String id, Number value) {
+        printType(id, "gauge");
+        appendId(id);
+        response.append(' ').append(value.toString()).append('\n');
+    }
+
+    private void printType(String id, String type) {
+        response.append("# TYPE ");
+        appendId(id);
+        response.append(' ').append(type).append('\n');
+    }
+
+    public void reset() {
+        response.setLength(0);
+    }
+
+    public int length() {
+        return response.length();
+    }
+
+    public CharSequence getReport() {
+        return response;
+    }
+
+    private void appendId(String id) {
+        response.append("appeng_");
+        // Sanitize to [a-zA-Z0-9:_]
+        for (int i = 0; i < id.length(); i++) {
+            char ch = id.charAt(i);
+            if (ch >= 'a' && ch <= 'z' || ch >= 'A' && ch <= 'Z' || ch >= '0' && ch <= '9' || ch == ':' || ch == '_') {
+                response.append(ch);
+            } else {
+                response.append('_');
+            }
+        }
+    }
+
+}

src/main/java/appeng/mixins/structure/BiomeAccessor.java

@@ -7,7 +7,6 @@ import org.spongepowered.asm.mixin.Mixin;
 import org.spongepowered.asm.mixin.gen.Accessor;
 
 import net.minecraft.world.biome.Biome;
-import net.minecraft.world.gen.feature.StructureFeature;
 import net.minecraft.world.gen.feature.structure.Structure;
 
 /**

src/main/java/appeng/parts/automation/AnnihilationPlanePart.java

@@ -34,7 +34,6 @@ import net.minecraft.item.Items;
 import net.minecraft.tags.BlockTags;
 import net.minecraft.tags.ITag;
 import net.minecraft.tags.ItemTags;
-import net.minecraft.tags.Tag;
 import net.minecraft.tileentity.TileEntity;
 import net.minecraft.util.ResourceLocation;
 import net.minecraft.util.math.AxisAlignedBB;

src/main/java/appeng/server/Commands.java

@@ -19,6 +19,7 @@
 package appeng.server;
 
 import appeng.server.subcommands.ChunkLogger;
+import appeng.server.subcommands.MetricsCommand;
 import appeng.server.subcommands.SpatialStorageCommand;
 import appeng.server.subcommands.Supporters;
 import appeng.server.subcommands.TestMeteoritesCommand;
@@ -27,7 +28,7 @@ import appeng.server.subcommands.TestOreGenCommand;
 public enum Commands {
     Chunklogger(4, new ChunkLogger(), false), Supporters(0, new Supporters(), false),
     TestOreGen(4, new TestOreGenCommand(), true), TestMeteorites(4, new TestMeteoritesCommand(), true),
-    Spatial(4, new SpatialStorageCommand(), false);
+    Spatial(4, new SpatialStorageCommand(), false), Metrics(4, new MetricsCommand(), false);
 
     public final int level;
     public final ISubCommand command;

src/main/java/appeng/server/subcommands/MetricsCommand.java

@@ -0,0 +1,25 @@
+package appeng.server.subcommands;
+
+import com.mojang.brigadier.context.CommandContext;
+
+import net.minecraft.command.CommandSource;
+import net.minecraft.server.MinecraftServer;
+import net.minecraft.util.text.StringTextComponent;
+
+import appeng.metrics.Metrics;
+import appeng.metrics.reporter.PrintStreamReporter;
+import appeng.server.ISubCommand;
+
+/**
+ * A simple way of printing out AE2's metrics on the server console.
+ */
+public class MetricsCommand implements ISubCommand {
+    @Override
+    public void call(MinecraftServer srv, CommandContext<CommandSource> ctx, CommandSource sender) {
+        System.out.println("-------- AE2 Metrics:");
+        Metrics.visit(new PrintStreamReporter(System.out));
+        System.out.println("-------- END");
+
+        sender.sendFeedback(new StringTextComponent("Metrics reported to server console..."), false);
+    }
+}

src/main/resources/assets/appliedenergistics2/lang/en_us.json

@@ -705,5 +705,9 @@
   "waila.appliedenergistics2.P2POutput": "Linked (Output Side)",
   "waila.appliedenergistics2.P2PUnlinked": "Unlinked",
   "waila.appliedenergistics2.Showing": "Showing",
-  "waila.appliedenergistics2.Unlocked": "Unlocked"
+  "waila.appliedenergistics2.Unlocked": "Unlocked",
+  "jei.appliedenergistics2.missing_id": "Cannot identify recipe",
+  "jei.appliedenergistics2.recipe_too_large": "Recipe larger than 3x3",
+  "jei.appliedenergistics2.requires_processing_mode": "Requires processing mode",
+  "jei.appliedenergistics2.no_output": "Recipe has no output"
 }