Cache 1.17.1 light by default, add config option

api/src/main/java/com/viaversion/viaversion/api/configuration/ViaVersionConfig.java

@@ -453,4 +453,6 @@ public interface ViaVersionConfig {
      * @return the global map from vanilla dimensions to world name
      */
     WorldIdentifiers get1_16WorldNamesMap();
+
+    boolean cache1_17Light();
 }

common/src/main/java/com/viaversion/viaversion/configuration/AbstractViaConfig.java

@@ -88,6 +88,7 @@ public abstract class AbstractViaConfig extends Config implements ViaVersionConf
     private boolean forcedUse1_17ResourcePack;
     private JsonElement resourcePack1_17PromptMessage;
     private WorldIdentifiers map1_16WorldNames;
+    private boolean cache1_17Light;
 
     protected AbstractViaConfig(File configFile) {
         super(configFile);
@@ -155,6 +156,7 @@ public abstract class AbstractViaConfig extends Config implements ViaVersionConf
         map1_16WorldNames = new WorldIdentifiers(worlds.getOrDefault("overworld", WorldIdentifiers.OVERWORLD_DEFAULT),
                 worlds.getOrDefault("nether", WorldIdentifiers.NETHER_DEFAULT),
                 worlds.getOrDefault("end", WorldIdentifiers.END_DEFAULT));
+        cache1_17Light = getBoolean("cache-1_17-light", true);
     }
 
     private BlockedProtocolVersions loadBlockedProtocolVersions() {
@@ -516,4 +518,9 @@ public abstract class AbstractViaConfig extends Config implements ViaVersionConf
     public WorldIdentifiers get1_16WorldNamesMap() {
         return map1_16WorldNames;
     }
+
+    @Override
+    public boolean cache1_17Light() {
+        return cache1_17Light;
+    }
 }

common/src/main/java/com/viaversion/viaversion/protocols/protocol1_18to1_17_1/packets/WorldPackets.java

@@ -67,7 +67,7 @@ public final class WorldPackets {
                 handler(wrapper -> {
                     final int chunkX = wrapper.passthrough(Type.VAR_INT);
                     final int chunkZ = wrapper.passthrough(Type.VAR_INT);
-                    if (wrapper.user().get(ChunkLightStorage.class).isLoaded(chunkX, chunkZ)) {
+                    if (!Via.getConfig().cache1_17Light() && wrapper.user().get(ChunkLightStorage.class).isLoaded(chunkX, chunkZ)) {
                         // Light packets updating already sent chunks are the same as before
                         return;
                     }
@@ -162,9 +162,9 @@ public final class WorldPackets {
                     final ChunkLightStorage lightStorage = wrapper.user().get(ChunkLightStorage.class);
                     final boolean alreadyLoaded = !lightStorage.addLoadedChunk(chunk.getX(), chunk.getZ());
 
-                    // Get and remove light stored, there's only full chunk packets //TODO Only get, not remove if we find out people re-send full chunk packets without re-sending light
                     // Append light data to chunk packet
-                    final ChunkLightStorage.ChunkLight light = lightStorage.removeLight(chunk.getX(), chunk.getZ());
+                    final ChunkLightStorage.ChunkLight light = Via.getConfig().cache1_17Light() ?
+                            lightStorage.getLight(chunk.getX(), chunk.getZ()) : lightStorage.removeLight(chunk.getX(), chunk.getZ());
                     if (light == null) {
                         Via.getPlatform().getLogger().warning("No light data found for chunk at " + chunk.getX() + ", " + chunk.getZ() + ". Chunk was already loaded: " + alreadyLoaded);
 

common/src/main/java/com/viaversion/viaversion/protocols/protocol1_18to1_17_1/storage/ChunkLightStorage.java

@@ -38,6 +38,10 @@ public final class ChunkLightStorage implements StorableObject {
         return lightPackets.remove(getChunkSectionIndex(x, z));
     }
 
+    public @Nullable ChunkLight getLight(final int x, final int z) {
+        return lightPackets.get(getChunkSectionIndex(x, z));
+    }
+
     public boolean addLoadedChunk(final int x, final int z) {
         return loadedChunks.add(getChunkSectionIndex(x, z));
     }

common/src/main/resources/assets/viaversion/config.yml

@@ -160,6 +160,10 @@ forced-use-1_17-resource-pack: false
 # The message to be displayed at the prompt when the 1.17+ client receives the server resource pack.
 resource-pack-1_17-prompt: ''
 #
+# Caches light until chunks are unloaded to allow subsequent chunk update packets as opposed to instantly uncaching when the first chunk data is sent.
+# Only disable this if you know what you are doing.
+cache-1_17-light: true
+#
 #----------------------------------------------------------#
 #             1.9+ CLIENTS ON 1.8 SERVERS OPTIONS          #
 #----------------------------------------------------------#