From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Wed, 12 Sep 2018 21:47:01 -0400
Subject: [PATCH] Optimize Biome Mob Lookups for Mob Spawning

Uses an EnumMap as well as a Set paired List for O(1) contains calls.

diff --git a/src/main/java/net/minecraft/world/level/biome/MobSpawnSettings.java b/src/main/java/net/minecraft/world/level/biome/MobSpawnSettings.java
index 58ee27a994b4cd845b8bb28e80cc2102c860f097..528f42c63a1186b8827bfe7cf6193e14da938cb3 100644
--- a/src/main/java/net/minecraft/world/level/biome/MobSpawnSettings.java
+++ b/src/main/java/net/minecraft/world/level/biome/MobSpawnSettings.java
@@ -30,19 +30,28 @@ public class MobSpawnSettings {
     }, (enumcreaturetype) -> {
         return ImmutableList.of();
     })), ImmutableMap.of(), false);
+    // Paper start- decompile error workaround
+    private static class bProxy extends MobSpawnSettings.MobSpawnCost {
+        private bProxy(double gravityLimit, double mass) {
+            super(gravityLimit, mass);
+        }
+    }
+    private static class cProxy extends MobSpawnSettings.SpawnerData {
+        public cProxy(EntityType<?> type, int weight, int minGroupSize, int maxGroupSize) {
+            super(type, weight, minGroupSize, maxGroupSize);
+        }
+    };
+    // Paper end
     public static final MapCodec<MobSpawnSettings> CODEC = RecordCodecBuilder.mapCodec((instance) -> {
-        RecordCodecBuilder recordcodecbuilder = Codec.FLOAT.optionalFieldOf("creature_spawn_probability", 0.1F).forGetter((biomesettingsmobs) -> {
-            return biomesettingsmobs.d;
+        RecordCodecBuilder<MobSpawnSettings, Float> recordcodecbuilder = Codec.FLOAT.optionalFieldOf("creature_spawn_probability", 0.1F).forGetter((biomesettingsmobs) -> { // Paper - add type to builder
+            return biomesettingsmobs.creatureGenerationProbability;
         });
-        Codec codec = MobCategory.CODEC;
-        Codec codec1 = BiomeSettingsMobs.c.b.listOf();
-        Logger logger = MobSpawnSettings.LOGGER;
-
-        logger.getClass();
-        return instance.group(recordcodecbuilder, Codec.simpleMap(codec, codec1.promotePartial(Util.prefix("Spawn data: ", logger::error)), StringRepresentable.keys(MobCategory.values())).fieldOf("spawners").forGetter((biomesettingsmobs) -> {
-            return biomesettingsmobs.e;
-        }), Codec.simpleMap(Registry.ENTITY_TYPE, BiomeSettingsMobs.b.a, Registry.ENTITY_TYPE).fieldOf("spawn_costs").forGetter((biomesettingsmobs) -> {
-            return biomesettingsmobs.f;
+        // Paper - remove unused vars
+
+        return instance.group(recordcodecbuilder, Codec.simpleMap(MobCategory.CODEC, cProxy.CODEC.listOf().promotePartial(Util.prefix("Spawn data: ", MobSpawnSettings.LOGGER::error)), StringRepresentable.keys(MobCategory.values())).fieldOf("spawners").forGetter((biomesettingsmobs) -> { // Paper - inline codec, cProxy, LOGGER
+            return biomesettingsmobs.spawners;
+        }), Codec.simpleMap(Registry.ENTITY_TYPE, bProxy.CODEC, Registry.ENTITY_TYPE).fieldOf("spawn_costs").forGetter((biomesettingsmobs) -> { // Paper - decompile error - bProxy
+            return biomesettingsmobs.mobSpawnCosts;
         }), Codec.BOOL.fieldOf("player_spawn_friendly").orElse(false).forGetter(MobSpawnSettings::playerSpawnFriendly)).apply(instance, MobSpawnSettings::new);
     });
     private final float creatureGenerationProbability;
@@ -76,11 +85,43 @@ public class MobSpawnSettings {
 
     public static class Builder {
 
-        private final Map<MobCategory, List<MobSpawnSettings.SpawnerData>> spawners = (Map) Stream.of(MobCategory.values()).collect(ImmutableMap.toImmutableMap((enumcreaturetype) -> {
+        // Paper start - keep track of data in a pair set to give O(1) contains calls - we have to hook removals incase plugins mess with it
+        public static class MobList extends java.util.ArrayList<MobSpawnSettings.SpawnerData> {
+            java.util.Set<MobSpawnSettings.SpawnerData> biomes = new java.util.HashSet<>();
+
+            @Override
+            public boolean contains(Object o) {
+                return biomes.contains(o);
+            }
+
+            @Override
+            public boolean add(MobSpawnSettings.SpawnerData BiomeSettingsMobs) {
+                biomes.add(BiomeSettingsMobs);
+                return super.add(BiomeSettingsMobs);
+            }
+
+            @Override
+            public MobSpawnSettings.SpawnerData remove(int index) {
+                MobSpawnSettings.SpawnerData removed = super.remove(index);
+                if (removed != null) {
+                    biomes.remove(removed);
+                }
+                return removed;
+            }
+
+            @Override
+            public void clear() {
+                biomes.clear();
+                super.clear();
+            }
+        }
+        // use toImmutableEnumMap collector
+        private final Map<MobCategory, List<MobSpawnSettings.SpawnerData>> spawners = (Map) Stream.of(MobCategory.values()).collect(Maps.toImmutableEnumMap((enumcreaturetype) -> {
             return enumcreaturetype;
         }, (enumcreaturetype) -> {
-            return Lists.newArrayList();
+            return new MobList(); // Use MobList instead of ArrayList
         }));
+        // Paper end
         private final Map<EntityType<?>, MobSpawnSettings.MobSpawnCost> mobSpawnCosts = Maps.newLinkedHashMap();
         private float creatureGenerationProbability = 0.1F;
         private boolean playerCanSpawn;