Asynchronously load mappings (until needed), create optional mappings cache for VB

bukkit/src/main/java/us/myles/ViaVersion/ViaVersionPlugin.java

@@ -10,6 +10,7 @@ import us.myles.ViaVersion.api.Via;
 import us.myles.ViaVersion.api.ViaAPI;
 import us.myles.ViaVersion.api.command.ViaCommandSender;
 import us.myles.ViaVersion.api.configuration.ConfigurationProvider;
+import us.myles.ViaVersion.api.data.MappingDataLoader;
 import us.myles.ViaVersion.api.platform.TaskId;
 import us.myles.ViaVersion.api.platform.ViaPlatform;
 import us.myles.ViaVersion.bukkit.classgenerator.ClassGenerator;
@@ -82,6 +83,10 @@ public class ViaVersionPlugin extends JavaPlugin implements ViaPlatform {
             compatSpigotBuild = false;
         }
 
+        if (getServer().getPluginManager().getPlugin("ViaBackwards") != null) {
+            MappingDataLoader.setCacheJsonMappings(true);
+        }
+
         // Generate classes needed (only works if it's compat or ps)
         ClassGenerator.generate();
         lateBind = !BukkitViaInjector.isBinded();

bungee/src/main/java/us/myles/ViaVersion/BungeePlugin.java

@@ -12,6 +12,7 @@ import us.myles.ViaVersion.api.Via;
 import us.myles.ViaVersion.api.ViaAPI;
 import us.myles.ViaVersion.api.command.ViaCommandSender;
 import us.myles.ViaVersion.api.configuration.ConfigurationProvider;
+import us.myles.ViaVersion.api.data.MappingDataLoader;
 import us.myles.ViaVersion.api.data.UserConnection;
 import us.myles.ViaVersion.api.platform.TaskId;
 import us.myles.ViaVersion.api.platform.ViaPlatform;
@@ -37,7 +38,7 @@ public class BungeePlugin extends Plugin implements ViaPlatform, Listener {
     @Override
     public void onLoad() {
         try {
-            ProtocolConstants.class.getField("MINECRAFT_1_14_4");
+            ProtocolConstants.class.getField("MINECRAFT_1_15_2");
         } catch (NoSuchFieldException e) {
             getLogger().warning("      / \\");
             getLogger().warning("     /   \\");
@@ -47,10 +48,12 @@ public class BungeePlugin extends Plugin implements ViaPlatform, Listener {
             getLogger().warning(" /     o     \\");
             getLogger().warning("/_____________\\");
         }
+
         api = new BungeeViaAPI();
         config = new BungeeViaConfig(getDataFolder());
         commandHandler = new BungeeCommandHandler();
         ProxyServer.getInstance().getPluginManager().registerCommand(this, new BungeeCommand(commandHandler));
+
         // Init platform
         Via.init(ViaManager.builder()
                 .platform(this)
@@ -62,6 +65,10 @@ public class BungeePlugin extends Plugin implements ViaPlatform, Listener {
 
     @Override
     public void onEnable() {
+        if (ProxyServer.getInstance().getPluginManager().getPlugin("ViaBackwards") != null) {
+            MappingDataLoader.setCacheJsonMappings(true);
+        }
+
         // Inject
         Via.getManager().init();
     }

common/src/main/java/us/myles/ViaVersion/api/Via.java

@@ -7,6 +7,7 @@ import us.myles.ViaVersion.api.platform.ViaPlatform;
 public class Via {
     private static ViaPlatform platform;
     private static ViaManager manager;
+    private static boolean cacheJsonMappings;
 
     /**
      * Register the ViaManager associated with the platform.

common/src/main/java/us/myles/ViaVersion/api/data/MappingDataLoader.java

@@ -5,10 +5,36 @@ import us.myles.ViaVersion.api.Via;
 import us.myles.ViaVersion.util.GsonUtil;
 
 import java.io.*;
+import java.util.HashMap;
 import java.util.Map;
 
 public class MappingDataLoader {
 
+    private static final Map<String, JsonObject> MAPPINGS_CACHE = new HashMap<>();
+    private static boolean cacheJsonMappings;
+
+    /**
+     * Returns true if a selected number of mappings should be cached.
+     * If enabled, cleanup should be done after the cache is no longer needed.
+     *
+     * @return true if mappings should be cached
+     */
+    public static boolean cacheJsonMappings() {
+        return cacheJsonMappings;
+    }
+
+    public static void setCacheJsonMappings(boolean cacheJsonMappings) {
+        MappingDataLoader.cacheJsonMappings = cacheJsonMappings;
+        Via.getPlatform().getLogger().info("Enabled caching of mappingdata for ViaBackwards!");
+    }
+
+    /**
+     * @see #cacheJsonMappings()
+     */
+    public static Map<String, JsonObject> getMappingsCache() {
+        return MAPPINGS_CACHE;
+    }
+
     public static JsonObject loadFromDataDir(String name) {
         File file = new File(Via.getPlatform().getDataFolder(), name);
         if (!file.exists()) return loadData(name);
@@ -27,10 +53,18 @@ public class MappingDataLoader {
     }
 
     public static JsonObject loadData(String name) {
+        return loadData(name, false);
+    }
+
+    public static JsonObject loadData(String name, boolean cacheIfEnabled) {
         InputStream stream = getResource(name);
         InputStreamReader reader = new InputStreamReader(stream);
         try {
-            return GsonUtil.getGson().fromJson(reader, JsonObject.class);
+            JsonObject object = GsonUtil.getGson().fromJson(reader, JsonObject.class);
+            if (cacheIfEnabled && cacheJsonMappings) {
+                MAPPINGS_CACHE.put(name, object);
+            }
+            return object;
         } finally {
             try {
                 reader.close();

common/src/main/java/us/myles/ViaVersion/api/protocol/Protocol.java

@@ -18,8 +18,14 @@ public abstract class Protocol {
     private final Map<Packet, ProtocolPacket> incoming = new HashMap<>();
     private final Map<Packet, ProtocolPacket> outgoing = new HashMap<>();
     private final Map<Class, Object> storedObjects = new HashMap<>(); // currently only used for MetadataRewriters
+    private final boolean hasMappingDataToLoad;
 
     public Protocol() {
+        this(false);
+    }
+
+    public Protocol(boolean hasMappingDataToLoad) {
+        this.hasMappingDataToLoad = hasMappingDataToLoad;
         registerPackets();
     }
 
@@ -51,6 +57,14 @@ public abstract class Protocol {
      */
     protected abstract void registerPackets();
 
+    /**
+     * Load mapping data for the protocol.
+     * <p>
+     * To be overridden if needed.
+     */
+    protected void loadMappingData() {
+    }
+
     /**
      * Handle protocol registration phase, use this to register providers / tasks.
      * <p>
@@ -164,6 +178,10 @@ public abstract class Protocol {
         cancelOutgoing(state, oldPacketID, -1);
     }
 
+    public boolean hasMappingDataToLoad() {
+        return hasMappingDataToLoad;
+    }
+
     /**
      * Transform a packet using this protocol
      *

common/src/main/java/us/myles/ViaVersion/api/protocol/ProtocolRegistry.java

@@ -2,9 +2,9 @@ package us.myles.ViaVersion.api.protocol;
 
 import com.google.common.collect.Lists;
 import com.google.common.collect.Range;
-import com.google.common.collect.Sets;
 import us.myles.ViaVersion.api.Pair;
 import us.myles.ViaVersion.api.Via;
+import us.myles.ViaVersion.api.data.MappingDataLoader;
 import us.myles.ViaVersion.protocols.base.BaseProtocol;
 import us.myles.ViaVersion.protocols.base.BaseProtocol1_7;
 import us.myles.ViaVersion.protocols.protocol1_10to1_9_3.Protocol1_10To1_9_3_4;
@@ -32,7 +32,7 @@ import us.myles.ViaVersion.protocols.protocol1_9to1_8.Protocol1_9To1_8;
 import us.myles.ViaVersion.protocols.protocol1_9to1_9_1.Protocol1_9To1_9_1;
 
 import java.util.*;
-import java.util.concurrent.ConcurrentHashMap;
+import java.util.concurrent.*;
 
 public class ProtocolRegistry {
     public static final Protocol BASE_PROTOCOL = new BaseProtocol();
@@ -40,11 +40,17 @@ public class ProtocolRegistry {
     // Input Version -> Output Version & Protocol (Allows fast lookup)
     private static final Map<Integer, Map<Integer, Protocol>> registryMap = new ConcurrentHashMap<>();
     private static final Map<Pair<Integer, Integer>, List<Pair<Integer, Protocol>>> pathCache = new ConcurrentHashMap<>();
-    private static final List<Protocol> registerList = Lists.newCopyOnWriteArrayList();
+    private static final List<Protocol> registerList = new ArrayList<>();
-    private static final Set<Integer> supportedVersions = Sets.newConcurrentHashSet();
+    private static final Set<Integer> supportedVersions = new HashSet<>();
     private static final List<Pair<Range<Integer>, Protocol>> baseProtocols = Lists.newCopyOnWriteArrayList();
 
+    private static Map<Class<? extends Protocol>, CompletableFuture<Void>> mappingLoaderFutures = new ConcurrentHashMap<>();
+    private static ThreadPoolExecutor mappingLoaderExecutor;
+
     static {
+        mappingLoaderExecutor = new ThreadPoolExecutor(5, 16, 45L, TimeUnit.SECONDS, new SynchronousQueue<>());
+        mappingLoaderExecutor.allowCoreThreadTimeOut(true);
+
         // Base Protocol
         registerBaseProtocol(BASE_PROTOCOL, Range.lessThan(Integer.MIN_VALUE));
         registerBaseProtocol(new BaseProtocol1_7(), Range.all());
@@ -102,15 +108,13 @@ public class ProtocolRegistry {
      */
     public static void registerProtocol(Protocol protocol, List<Integer> supported, Integer output) {
         // Clear cache as this may make new routes.
-        if (!pathCache.isEmpty())
+        if (!pathCache.isEmpty()) {
             pathCache.clear();
-
-        for (Integer version : supported) {
-            if (!registryMap.containsKey(version)) {
-                registryMap.put(version, new HashMap<>());
         }
 
-            registryMap.get(version).put(output, protocol);
+        for (Integer version : supported) {
+            Map<Integer, Protocol> protocolMap = registryMap.computeIfAbsent(version, k -> new HashMap<>());
+            protocolMap.put(output, protocol);
         }
 
         if (Via.getPlatform().isPluginEnabled()) {
@@ -119,6 +123,21 @@ public class ProtocolRegistry {
         } else {
             registerList.add(protocol);
         }
+
+        if (protocol.hasMappingDataToLoad()) {
+            if (mappingLoaderExecutor != null) {
+                // Submit mapping data loading
+                CompletableFuture<Void> future = new CompletableFuture<>();
+                mappingLoaderFutures.put(protocol.getClass(), future);
+                mappingLoaderExecutor.execute(() -> {
+                    protocol.loadMappingData();
+                    future.complete(null);
+                });
+            } else {
+                // Late protocol adding - just do it on the current thread
+                protocol.loadMappingData();
+            }
+        }
     }
 
     /**
@@ -248,7 +267,7 @@ public class ProtocolRegistry {
             return protocolList;
         }
         // Generate path
-        List<Pair<Integer, Protocol>> outputPath = getProtocolPath(new ArrayList<Pair<Integer, Protocol>>(), clientVersion, serverVersion);
+        List<Pair<Integer, Protocol>> outputPath = getProtocolPath(new ArrayList<>(), clientVersion, serverVersion);
         // If it found a path, cache it.
         if (outputPath != null) {
             pathCache.put(protocolKey, outputPath);
@@ -274,4 +293,53 @@ public class ProtocolRegistry {
         return false;
     }
 
+    /**
+     * Ensure that mapping data for that protocol has already been loaded, completes it otherwise.
+     *
+     * @param protocolClass protocol class
+     */
+    public static void completeMappingDataLoading(Class<? extends Protocol> protocolClass) throws Exception {
+        if (mappingLoaderFutures == null) return;
+
+        CompletableFuture<Void> future = mappingLoaderFutures.remove(protocolClass);
+        if (future == null) return;
+
+        future.get();
+
+        if (mappingLoaderFutures.isEmpty()) {
+            shutdownLoaderExecutor();
+        }
+    }
+
+    /**
+     * Ensure that all mapping data has already been loaded, completes it otherwise.
+     */
+    public static void completeMappingDataLoading() throws Exception {
+        if (mappingLoaderFutures == null) return;
+
+        for (CompletableFuture<Void> future : mappingLoaderFutures.values()) {
+            future.get();
+        }
+
+        mappingLoaderFutures.clear();
+        shutdownLoaderExecutor();
+    }
+
+    private static void shutdownLoaderExecutor() {
+        mappingLoaderExecutor.shutdown();
+        mappingLoaderExecutor = null;
+        mappingLoaderFutures = null;
+        if (MappingDataLoader.cacheJsonMappings()) {
+            MappingDataLoader.getMappingsCache().clear();
+        }
+    }
+
+    public static void getMappingLoaderFuture(Class<? extends Protocol> protocolClass, Runnable runnable) {
+        CompletableFuture<Void> future = mappingLoaderFutures.get(protocolClass);
+        if (future != null) {
+            future.whenComplete((v, t) -> runnable.run());
+        } else {
+            runnable.run();
+        }
+    }
 }

common/src/main/java/us/myles/ViaVersion/protocols/base/BaseProtocol.java

@@ -58,6 +58,8 @@ public class BaseProtocol extends Protocol {
                         if (protocols != null) {
                             for (Pair<Integer, Protocol> prot : protocols) {
                                 pipeline.add(prot.getValue());
+                                // Ensure mapping data has already been loaded
+                                ProtocolRegistry.completeMappingDataLoading(prot.getValue().getClass());
                             }
                             wrapper.set(Type.VAR_INT, 0, protocol);
                         }

common/src/main/java/us/myles/ViaVersion/protocols/protocol1_13to1_12_2/Protocol1_13To1_12_2.java

@@ -42,14 +42,15 @@ import java.util.Map;
 
 public class Protocol1_13To1_12_2 extends Protocol {
 
-    public static final PacketHandler POS_TO_3_INT = new PacketHandler() {
+    public Protocol1_13To1_12_2() {
-        @Override
+        super(true);
-        public void handle(PacketWrapper wrapper) throws Exception {
+    }
+
+    public static final PacketHandler POS_TO_3_INT = wrapper -> {
         Position position = wrapper.read(Type.POSITION);
         wrapper.write(Type.INT, position.getX());
         wrapper.write(Type.INT, (int) position.getY());
         wrapper.write(Type.INT, position.getZ());
-        }
     };
 
     public static final PacketHandler SEND_DECLARE_COMMANDS_AND_TAGS =
@@ -132,11 +133,6 @@ public class Protocol1_13To1_12_2 extends Protocol {
         SCOREBOARD_TEAM_NAME_REWRITE.put(ChatColor.UNDERLINE, ':');
         SCOREBOARD_TEAM_NAME_REWRITE.put(ChatColor.ITALIC, ';');
         SCOREBOARD_TEAM_NAME_REWRITE.put(ChatColor.RESET, '/');
-
-        MappingData.init();
-        ConnectionData.init();
-        RecipeData.init();
-        BlockIdData.init();
     }
 
     @Override
@@ -1151,6 +1147,14 @@ public class Protocol1_13To1_12_2 extends Protocol {
         registerIncoming(State.PLAY, 0x20, 0x2A);
     }
 
+    @Override
+    protected void loadMappingData() {
+        MappingData.init();
+        ConnectionData.init();
+        RecipeData.init();
+        BlockIdData.init();
+    }
+
     @Override
     public void init(UserConnection userConnection) {
         userConnection.put(new EntityTracker1_13(userConnection));

common/src/main/java/us/myles/ViaVersion/protocols/protocol1_13to1_12_2/blockconnections/ConnectionData.java

@@ -195,7 +195,7 @@ public class ConnectionData {
     public static void init() {
         if (!Via.getConfig().isServersideBlockConnections()) return;
         Via.getPlatform().getLogger().info("Loading block connection mappings ...");
-        JsonObject mapping1_13 = MappingDataLoader.loadData("mapping-1.13.json");
+        JsonObject mapping1_13 = MappingDataLoader.loadData("mapping-1.13.json", true);
         JsonObject blocks1_13 = mapping1_13.getAsJsonObject("blocks");
         for (Entry<String, JsonElement> blockState : blocks1_13.entrySet()) {
             Integer id = Integer.parseInt(blockState.getKey());

common/src/main/java/us/myles/ViaVersion/protocols/protocol1_13to1_12_2/data/MappingData.java

@@ -33,23 +33,19 @@ public class MappingData {
     public static Mappings blockMappings;
 
     public static void init() {
-        JsonObject mapping1_12 = MappingDataLoader.loadData("mapping-1.12.json");
+        JsonObject mapping1_12 = MappingDataLoader.loadData("mapping-1.12.json", true);
-        JsonObject mapping1_13 = MappingDataLoader.loadData("mapping-1.13.json");
+        JsonObject mapping1_13 = MappingDataLoader.loadData("mapping-1.13.json", true);
+        Via.getPlatform().getLogger().info("Loading 1.12.2 -> 1.13 mappings...");
 
-        Via.getPlatform().getLogger().info("Loading 1.12.2 -> 1.13 block mapping...");
         blockMappings = new BlockMappingsShortArray(mapping1_12.getAsJsonObject("blocks"), mapping1_13.getAsJsonObject("blocks"));
-        Via.getPlatform().getLogger().info("Loading 1.12.2 -> 1.13 item mapping...");
         MappingDataLoader.mapIdentifiers(oldToNewItems, mapping1_12.getAsJsonObject("items"), mapping1_13.getAsJsonObject("items"));
-        Via.getPlatform().getLogger().info("Loading new 1.13 tags...");
         loadTags(blockTags, mapping1_13.getAsJsonObject("block_tags"));
         loadTags(itemTags, mapping1_13.getAsJsonObject("item_tags"));
         loadTags(fluidTags, mapping1_13.getAsJsonObject("fluid_tags"));
-        Via.getPlatform().getLogger().info("Loading 1.12.2 -> 1.13 enchantment mapping...");
+
         loadEnchantments(oldEnchantmentsIds, mapping1_12.getAsJsonObject("enchantments"));
         enchantmentMappings = new Mappings(72, mapping1_12.getAsJsonObject("enchantments"), mapping1_13.getAsJsonObject("enchantments"));
-        Via.getPlatform().getLogger().info("Loading 1.12.2 -> 1.13 sound mapping...");
         soundMappings = new Mappings(662, mapping1_12.getAsJsonArray("sounds"), mapping1_13.getAsJsonArray("sounds"));
-        Via.getPlatform().getLogger().info("Loading 1.12.2 -> 1.13 plugin channel mappings...");
 
         JsonObject object = MappingDataLoader.loadFromDataDir("channelmappings-1.13.json");
         if (object != null) {
@@ -64,7 +60,6 @@ public class MappingData {
             }
         }
 
-        Via.getPlatform().getLogger().info("Loading translation mappping");
         Map<String, String> translateData = GsonUtil.getGson().fromJson(
                 new InputStreamReader(MappingData.class.getClassLoader().getResourceAsStream("assets/viaversion/data/mapping-lang-1.12-1.13.json")),
                 new TypeToken<Map<String, String>>() {

common/src/main/java/us/myles/ViaVersion/protocols/protocol1_14to1_13_2/Protocol1_14To1_13_2.java

@@ -19,8 +19,8 @@ import us.myles.ViaVersion.protocols.protocol1_9_3to1_9_1_2.storage.ClientWorld;
 
 public class Protocol1_14To1_13_2 extends Protocol {
 
-    static {
+    public Protocol1_14To1_13_2() {
-        MappingData.init();
+        super(true);
     }
 
     @Override
@@ -254,6 +254,14 @@ public class Protocol1_14To1_13_2 extends Protocol {
         registerIncoming(State.PLAY, 0x2A, 0x2D);
     }
 
+    @Override
+    protected void loadMappingData() {
+        MappingData.init();
+        WorldPackets.air = MappingData.blockStateMappings.getNewId(0);
+        WorldPackets.voidAir = MappingData.blockStateMappings.getNewId(8591);
+        WorldPackets.caveAir = MappingData.blockStateMappings.getNewId(8592);
+    }
+
     public static int getNewSoundId(int id) {
         int newId = MappingData.soundMappings.getNewId(id);
         if (newId == -1) {

common/src/main/java/us/myles/ViaVersion/protocols/protocol1_14to1_13_2/data/MappingData.java

@@ -23,26 +23,21 @@ public class MappingData {
     public static Set<Integer> nonFullBlocks;
 
     public static void init() {
-        JsonObject mapping1_13_2 = MappingDataLoader.loadData("mapping-1.13.2.json");
+        JsonObject mapping1_13_2 = MappingDataLoader.loadData("mapping-1.13.2.json", true);
-        JsonObject mapping1_14 = MappingDataLoader.loadData("mapping-1.14.json");
+        JsonObject mapping1_14 = MappingDataLoader.loadData("mapping-1.14.json", true);
+        Via.getPlatform().getLogger().info("Loading 1.13.2 -> 1.14 mappings...");
 
-        Via.getPlatform().getLogger().info("Loading 1.13.2 -> 1.14 blockstate mapping...");
         blockStateMappings = new Mappings(mapping1_13_2.getAsJsonObject("blockstates"), mapping1_14.getAsJsonObject("blockstates"));
-        Via.getPlatform().getLogger().info("Loading 1.13.2 -> 1.14 block mapping...");
         blockMappings = new Mappings(mapping1_13_2.getAsJsonObject("blocks"), mapping1_14.getAsJsonObject("blocks"));
-        Via.getPlatform().getLogger().info("Loading 1.13.2 -> 1.14 item mapping...");
         MappingDataLoader.mapIdentifiers(oldToNewItems, mapping1_13_2.getAsJsonObject("items"), mapping1_14.getAsJsonObject("items"));
-        Via.getPlatform().getLogger().info("Loading 1.13.2 -> 1.14 sound mapping...");
         soundMappings = new Mappings(mapping1_13_2.getAsJsonArray("sounds"), mapping1_14.getAsJsonArray("sounds"));
 
-        Via.getPlatform().getLogger().info("Loading 1.14 blockstates...");
         JsonObject blockStates = mapping1_14.getAsJsonObject("blockstates");
         Map<String, Integer> blockStateMap = new HashMap<>(blockStates.entrySet().size());
         for (Map.Entry<String, JsonElement> entry : blockStates.entrySet()) {
             blockStateMap.put(entry.getValue().getAsString(), Integer.parseInt(entry.getKey()));
         }
 
-        Via.getPlatform().getLogger().info("Loading 1.14 heightmap data...");
         JsonObject heightMapData = MappingDataLoader.loadData("heightMapData-1.14.json");
         JsonArray motionBlocking = heightMapData.getAsJsonArray("MOTION_BLOCKING");
         us.myles.ViaVersion.protocols.protocol1_14to1_13_2.data.MappingData.motionBlocking = new HashSet<>(motionBlocking.size());

common/src/main/java/us/myles/ViaVersion/protocols/protocol1_14to1_13_2/packets/WorldPackets.java

@@ -28,11 +28,11 @@ import us.myles.ViaVersion.util.CompactArrayUtil;
 import java.util.Arrays;
 
 public class WorldPackets {
-    private static final int AIR = MappingData.blockStateMappings.getNewId(0);
-    private static final int VOID_AIR = MappingData.blockStateMappings.getNewId(8591);
-    private static final int CAVE_AIR = MappingData.blockStateMappings.getNewId(8592);
     public static final int SERVERSIDE_VIEW_DISTANCE = 64;
     private static final byte[] FULL_LIGHT = new byte[2048];
+    public static int air;
+    public static int voidAir;
+    public static int caveAir;
 
     static {
         Arrays.fill(FULL_LIGHT, (byte) 0xff);
@@ -156,7 +156,7 @@ public class WorldPackets {
                             for (int i = 0; i < section.getPaletteSize(); i++) {
                                 int old = section.getPaletteEntry(i);
                                 int newId = Protocol1_14To1_13_2.getNewBlockStateId(old);
-                                if (!hasBlock && newId != AIR && newId != VOID_AIR && newId != CAVE_AIR) { // air, void_air, cave_air
+                                if (!hasBlock && newId != air && newId != voidAir && newId != caveAir) { // air, void_air, cave_air
                                     hasBlock = true;
                                 }
                                 section.setPaletteEntry(i, newId);
@@ -171,7 +171,7 @@ public class WorldPackets {
                                 for (int y = 0; y < 16; y++) {
                                     for (int z = 0; z < 16; z++) {
                                         int id = section.getFlatBlock(x, y, z);
-                                        if (id != AIR && id != VOID_AIR && id != CAVE_AIR) {
+                                        if (id != air && id != voidAir && id != caveAir) {
                                             nonAirBlockCount++;
                                             worldSurface[x + z * 16] = y + s * 16 + 1; // +1 (top of the block)
                                         }

common/src/main/java/us/myles/ViaVersion/protocols/protocol1_15to1_14_4/Protocol1_15To1_14_4.java

@@ -21,11 +21,14 @@ import us.myles.ViaVersion.protocols.protocol1_9_3to1_9_1_2.storage.ClientWorld;
 
 public class Protocol1_15To1_14_4 extends Protocol {
 
+    public Protocol1_15To1_14_4() {
+        super(true);
+    }
+
     @Override
     protected void registerPackets() {
         new MetadataRewriter1_15To1_14_4(this);
 
-        MappingData.init();
         EntityPackets.register(this);
         PlayerPackets.register(this);
         WorldPackets.register(this);
@@ -203,6 +206,11 @@ public class Protocol1_15To1_14_4 extends Protocol {
         registerOutgoing(State.PLAY, 0x59, 0x5A);
     }
 
+    @Override
+    protected void loadMappingData() {
+        MappingData.init();
+    }
+
     public static int getNewBlockStateId(int id) {
         int newId = MappingData.blockStateMappings.getNewId(id);
         if (newId == -1) {

common/src/main/java/us/myles/ViaVersion/protocols/protocol1_15to1_14_4/data/MappingData.java

@@ -15,16 +15,13 @@ public class MappingData {
 
     public static void init() {
         JsonObject diffmapping = MappingDataLoader.loadData("mappingdiff-1.14to1.15.json");
-        JsonObject mapping1_14 = MappingDataLoader.loadData("mapping-1.14.json");
+        JsonObject mapping1_14 = MappingDataLoader.loadData("mapping-1.14.json", true);
-        JsonObject mapping1_15 = MappingDataLoader.loadData("mapping-1.15.json");
+        JsonObject mapping1_15 = MappingDataLoader.loadData("mapping-1.15.json", true);
+        Via.getPlatform().getLogger().info("Loading 1.14.4 -> 1.15 mappings...");
 
-        Via.getPlatform().getLogger().info("Loading 1.14.4 -> 1.15 blockstate mapping...");
         blockStateMappings = new Mappings(mapping1_14.getAsJsonObject("blockstates"), mapping1_15.getAsJsonObject("blockstates"), diffmapping.getAsJsonObject("blockstates"));
-        Via.getPlatform().getLogger().info("Loading 1.14.4 -> 1.15 block mapping...");
         blockMappings = new Mappings(mapping1_14.getAsJsonObject("blocks"), mapping1_15.getAsJsonObject("blocks"));
-        Via.getPlatform().getLogger().info("Loading 1.14.4 -> 1.15 item mapping...");
         MappingDataLoader.mapIdentifiers(oldToNewItems, mapping1_14.getAsJsonObject("items"), mapping1_15.getAsJsonObject("items"));
-        Via.getPlatform().getLogger().info("Loading 1.14.4 -> 1.15 sound mapping...");
         soundMappings = new Mappings(mapping1_14.getAsJsonArray("sounds"), mapping1_15.getAsJsonArray("sounds"), false);
     }
 }

common/src/main/java/us/myles/ViaVersion/protocols/protocol1_16to1_15_2/Protocol1_16To1_15_2.java

@@ -20,11 +20,14 @@ import java.util.UUID;
 
 public class Protocol1_16To1_15_2 extends Protocol {
 
+    public Protocol1_16To1_15_2() {
+        super(true);
+    }
+
     @Override
     protected void registerPackets() {
         MetadataRewriter1_16To1_15_2 metadataRewriter = new MetadataRewriter1_16To1_15_2(this);
 
-        MappingData.init();
         EntityPackets.register(this);
         WorldPackets.register(this);
         InventoryPackets.register(this);
@@ -132,6 +135,11 @@ public class Protocol1_16To1_15_2 extends Protocol {
         registerOutgoing(State.PLAY, 0x4E, 0x43);
     }
 
+    @Override
+    protected void loadMappingData() {
+        MappingData.init();
+    }
+
     public static int getNewBlockStateId(int id) {
         int newId = MappingData.blockStateMappings.getNewId(id);
         if (newId == -1) {

common/src/main/java/us/myles/ViaVersion/protocols/protocol1_16to1_15_2/data/MappingData.java

@@ -19,16 +19,13 @@ public class MappingData {
 
     public static void init() {
         JsonObject diffmapping = MappingDataLoader.loadData("mappingdiff-1.15to1.16.json");
-        JsonObject mapping1_15 = MappingDataLoader.loadData("mapping-1.15.json");
+        JsonObject mapping1_15 = MappingDataLoader.loadData("mapping-1.15.json", true);
-        JsonObject mapping1_16 = MappingDataLoader.loadData("mapping-1.16.json");
+        JsonObject mapping1_16 = MappingDataLoader.loadData("mapping-1.16.json", true);
+        Via.getPlatform().getLogger().info("Loading 1.15 -> 1.16 mappings...");
 
-        Via.getPlatform().getLogger().info("Loading 1.15 -> 1.16 blockstate mapping...");
         blockStateMappings = new Mappings(mapping1_15.getAsJsonObject("blockstates"), mapping1_16.getAsJsonObject("blockstates"), diffmapping.getAsJsonObject("blockstates"));
-        Via.getPlatform().getLogger().info("Loading 1.15 -> 1.16 block mapping...");
         blockMappings = new Mappings(mapping1_15.getAsJsonObject("blocks"), mapping1_16.getAsJsonObject("blocks"));
-        Via.getPlatform().getLogger().info("Loading 1.15 -> 1.16 item mapping...");
         MappingDataLoader.mapIdentifiers(oldToNewItems, mapping1_15.getAsJsonObject("items"), mapping1_16.getAsJsonObject("items"), diffmapping.getAsJsonObject("items"));
-        Via.getPlatform().getLogger().info("Loading 1.15 -> 1.16 sound mapping...");
         soundMappings = new Mappings(mapping1_15.getAsJsonArray("sounds"), mapping1_16.getAsJsonArray("sounds"), diffmapping.getAsJsonObject("sounds"));
 
         attributeMappings.put("generic.maxHealth", "minecraft:generic.max_health");

sponge/src/main/java/us/myles/ViaVersion/SpongePlugin.java

@@ -19,6 +19,7 @@ import org.spongepowered.api.text.serializer.TextSerializers;
 import us.myles.ViaVersion.api.Via;
 import us.myles.ViaVersion.api.command.ViaCommandSender;
 import us.myles.ViaVersion.api.configuration.ConfigurationProvider;
+import us.myles.ViaVersion.api.data.MappingDataLoader;
 import us.myles.ViaVersion.api.platform.TaskId;
 import us.myles.ViaVersion.api.platform.ViaPlatform;
 import us.myles.ViaVersion.dump.PluginInfo;
@@ -68,7 +69,8 @@ public class SpongePlugin implements ViaPlatform {
         conf = new SpongeViaConfig(container, defaultConfig.getParentFile());
         SpongeCommandHandler commandHandler = new SpongeCommandHandler();
         game.getCommandManager().register(this, commandHandler, "viaversion", "viaver", "vvsponge");
-        getLogger().info("ViaVersion " + getPluginVersion() + " is now loaded!");
+        logger.info("ViaVersion " + getPluginVersion() + " is now loaded!");
+
         // Init platform
         Via.init(ViaManager.builder()
                 .platform(this)
@@ -80,6 +82,10 @@ public class SpongePlugin implements ViaPlatform {
 
     @Listener
     public void onServerStart(GameAboutToStartServerEvent event) {
+        if (game.getPluginManager().getPlugin("ViaBackwards").isPresent()) {
+            MappingDataLoader.setCacheJsonMappings(true);
+        }
+
         // Inject!
         logger.info("ViaVersion is injecting!");
         Via.getManager().init();

velocity/src/main/java/us/myles/ViaVersion/VelocityPlugin.java

@@ -18,6 +18,7 @@ import org.slf4j.Logger;
 import us.myles.ViaVersion.api.Via;
 import us.myles.ViaVersion.api.command.ViaCommandSender;
 import us.myles.ViaVersion.api.configuration.ConfigurationProvider;
+import us.myles.ViaVersion.api.data.MappingDataLoader;
 import us.myles.ViaVersion.api.data.UserConnection;
 import us.myles.ViaVersion.api.platform.TaskId;
 import us.myles.ViaVersion.api.platform.ViaPlatform;
@@ -73,6 +74,11 @@ public class VelocityPlugin implements ViaPlatform<Player> {
                 .commandHandler(commandHandler)
                 .loader(new VelocityViaLoader())
                 .injector(new VelocityViaInjector()).build());
+
+        if (proxy.getPluginManager().getPlugin("ViaBackwards").isPresent()) {
+            MappingDataLoader.setCacheJsonMappings(true);
+        }
+
         Via.getManager().init();
     }