Patches

patches/server/Allow-Saving-of-Oversized-Chunks.patch

@@ -0,0 +1,213 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Aikar <aikar@aikar.co>
+Date: Fri, 15 Feb 2019 01:08:19 -0500
+Subject: [PATCH] Allow Saving of Oversized Chunks
+
+Note 1.17 update: With 1.17, Entities are no longer stored in chunk slices, so this needs updating!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!!
+
+The Minecraft World Region File format has a hard cap of 1MB per chunk.
+This is due to the fact that the header of the file format only allocates
+a single byte for sector count, meaning a maximum of 256 sectors, at 4k per sector.
+
+This limit can be reached fairly easily with books, resulting in the chunk being unable
+to save to the world. Worse off, is that nothing printed when this occured, and silently
+performed a chunk rollback on next load.
+
+This leads to security risk with duplication and is being actively exploited.
+
+This patch catches the too large scenario, falls back and moves any large Entity
+or Tile Entity into a new compound, and this compound is saved into a different file.
+
+On Chunk Load, we check for oversized status, and if so, we load the extra file and
+merge the Entities and Tile Entities from the oversized chunk back into the level to
+then be loaded as normal.
+
+Once a chunk is returned back to normal size, the oversized flag will clear, and no
+extra data file will exist.
+
+This fix maintains compatability with all existing Anvil Region Format tools as it
+does not alter the save format. They will just not know about the extra entities.
+
+This fix also maintains compatability if someone switches server jars to one without
+this fix, as the data will remain in the oversized file. Once the server returns
+to a jar with this fix, the data will be restored.
+
+diff --git a/src/main/java/net/minecraft/world/level/chunk/storage/RegionFile.java b/src/main/java/net/minecraft/world/level/chunk/storage/RegionFile.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/world/level/chunk/storage/RegionFile.java
++++ b/src/main/java/net/minecraft/world/level/chunk/storage/RegionFile.java
+@@ -0,0 +0,0 @@ import java.nio.file.LinkOption;
+ import java.nio.file.Path;
+ import java.nio.file.StandardCopyOption;
+ import java.nio.file.StandardOpenOption;
++import java.util.zip.InflaterInputStream; // Paper
+ import javax.annotation.Nullable;
+ import net.minecraft.Util;
+ import net.minecraft.resources.ResourceLocation;
+ import net.minecraft.util.profiling.jfr.JvmProfiler;
++import net.minecraft.nbt.CompoundTag; // Paper
++import net.minecraft.nbt.NbtIo; // Paper
+ import net.minecraft.world.level.ChunkPos;
+ import org.slf4j.Logger;
+ 
+@@ -0,0 +0,0 @@ public class RegionFile implements AutoCloseable {
+     @VisibleForTesting
+     protected final RegionBitmap usedSectors;
+     public final java.util.concurrent.locks.ReentrantLock fileLock = new java.util.concurrent.locks.ReentrantLock(); // Paper
++    public final Path regionFile; // Paper
+ 
+     public RegionFile(RegionStorageInfo storageKey, Path directory, Path path, boolean dsync) throws IOException {
+         this(storageKey, directory, path, RegionFileVersion.getCompressionFormat(), dsync); // Paper - Configurable region compression format
+@@ -0,0 +0,0 @@ public class RegionFile implements AutoCloseable {
+ 
+     public RegionFile(RegionStorageInfo storageKey, Path path, Path directory, RegionFileVersion compressionFormat, boolean dsync) throws IOException {
+         this.header = ByteBuffer.allocateDirect(8192);
++        this.regionFile = file; // Paper
++        initOversizedState(); // Paper
+         this.usedSectors = new RegionBitmap();
+         this.info = storageKey;
+         this.path = path;
+@@ -0,0 +0,0 @@ public class RegionFile implements AutoCloseable {
+     }
+ 
+     public static final int MAX_CHUNK_SIZE = 500 * 1024 * 1024; // Paper - don't write garbage data to disk if writing serialization fails
++    // Paper start
++    private final byte[] oversized = new byte[1024];
++    private int oversizedCount;
++
++    private synchronized void initOversizedState() throws IOException {
++        Path metaFile = getOversizedMetaFile();
++        if (Files.exists(metaFile)) {
++            final byte[] read = java.nio.file.Files.readAllBytes(metaFile);
++            System.arraycopy(read, 0, oversized, 0, oversized.length);
++            for (byte temp : oversized) {
++                oversizedCount += temp;
++            }
++        }
++    }
++
++    private static int getChunkIndex(int x, int z) {
++        return (x & 31) + (z & 31) * 32;
++    }
++    synchronized boolean isOversized(int x, int z) {
++        return this.oversized[getChunkIndex(x, z)] == 1;
++    }
++    synchronized void setOversized(int x, int z, boolean oversized) throws IOException {
++        final int offset = getChunkIndex(x, z);
++        boolean previous = this.oversized[offset] == 1;
++        this.oversized[offset] = (byte) (oversized ? 1 : 0);
++        if (!previous && oversized) {
++            oversizedCount++;
++        } else if (!oversized && previous) {
++            oversizedCount--;
++        }
++        if (previous && !oversized) {
++            Path oversizedFile = getOversizedFile(x, z);
++            if (Files.exists(oversizedFile)) {
++                Files.delete(oversizedFile);
++            }
++        }
++        if (oversizedCount > 0) {
++            if (previous != oversized) {
++                writeOversizedMeta();
++            }
++        } else if (previous) {
++            Path oversizedMetaFile = getOversizedMetaFile();
++            if (Files.exists(oversizedMetaFile)) {
++                Files.delete(oversizedMetaFile);
++            }
++        }
++    }
++
++    private void writeOversizedMeta() throws IOException {
++        java.nio.file.Files.write(getOversizedMetaFile(), oversized);
++    }
++
++    private Path getOversizedMetaFile() {
++        return this.regionFile.getParent().resolve(this.regionFile.getFileName().toString().replaceAll("\\.mca$", "") + ".oversized.nbt");
++    }
++
++    private Path getOversizedFile(int x, int z) {
++        return this.regionFile.getParent().resolve(this.regionFile.getFileName().toString().replaceAll("\\.mca$", "") + "_oversized_" + x + "_" + z + ".nbt");
++    }
++
++    synchronized CompoundTag getOversizedData(int x, int z) throws IOException {
++        Path file = getOversizedFile(x, z);
++        try (DataInputStream out = new DataInputStream(new java.io.BufferedInputStream(new InflaterInputStream(Files.newInputStream(file))))) {
++            return NbtIo.read((java.io.DataInput) out);
++        }
++
++    }
++    // Paper end
+     private class ChunkBuffer extends ByteArrayOutputStream {
+ 
+         private final ChunkPos pos;
+diff --git a/src/main/java/net/minecraft/world/level/chunk/storage/RegionFileStorage.java b/src/main/java/net/minecraft/world/level/chunk/storage/RegionFileStorage.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/world/level/chunk/storage/RegionFileStorage.java
++++ b/src/main/java/net/minecraft/world/level/chunk/storage/RegionFileStorage.java
+@@ -0,0 +0,0 @@ public class RegionFileStorage implements AutoCloseable {
+         }
+     }
+ 
++    // Paper start
++    private static void printOversizedLog(String msg, Path file, int x, int z) {
++        org.apache.logging.log4j.LogManager.getLogger().fatal(msg + " (" + file.toString().replaceAll(".+[\\\\/]", "") + " - " + x + "," + z + ") Go clean it up to remove this message. /minecraft:tp " + (x<<4)+" 128 "+(z<<4) + " - DO NOT REPORT THIS TO PAPER - You may ask for help on Discord, but do not file an issue. These error messages can not be removed.");
++    }
++
++    private static CompoundTag readOversizedChunk(RegionFile regionfile, ChunkPos chunkCoordinate) throws IOException {
++        synchronized (regionfile) {
++            try (DataInputStream datainputstream = regionfile.getChunkDataInputStream(chunkCoordinate)) {
++                CompoundTag oversizedData = regionfile.getOversizedData(chunkCoordinate.x, chunkCoordinate.z);
++                CompoundTag chunk = NbtIo.read((DataInput) datainputstream);
++                if (oversizedData == null) {
++                    return chunk;
++                }
++                CompoundTag oversizedLevel = oversizedData.getCompound("Level");
++
++                mergeChunkList(chunk.getCompound("Level"), oversizedLevel, "Entities", "Entities");
++                mergeChunkList(chunk.getCompound("Level"), oversizedLevel, "TileEntities", "TileEntities");
++
++                return chunk;
++            } catch (Throwable throwable) {
++                throwable.printStackTrace();
++                throw throwable;
++            }
++        }
++    }
++
++    private static void mergeChunkList(CompoundTag level, CompoundTag oversizedLevel, String key, String oversizedKey) {
++        net.minecraft.nbt.ListTag levelList = level.getList(key, net.minecraft.nbt.Tag.TAG_COMPOUND);
++        net.minecraft.nbt.ListTag oversizedList = oversizedLevel.getList(oversizedKey, net.minecraft.nbt.Tag.TAG_COMPOUND);
++
++        if (!oversizedList.isEmpty()) {
++            levelList.addAll(oversizedList);
++            level.put(key, levelList);
++        }
++    }
++    // Paper end
++
+     @Nullable
+     public CompoundTag read(ChunkPos pos) throws IOException {
+         // CraftBukkit start - SPIGOT-5680: There's no good reason to preemptively create files on read, save that for writing
+@@ -0,0 +0,0 @@ public class RegionFileStorage implements AutoCloseable {
+         try { // Paper
+         DataInputStream datainputstream = regionfile.getChunkDataInputStream(pos);
+ 
++        // Paper start
++        if (regionfile.isOversized(pos.x, pos.z)) {
++            printOversizedLog("Loading Oversized Chunk!", regionfile.regionFile, pos.x, pos.z);
++            return readOversizedChunk(regionfile, pos);
++        }
++        // Paper end
+         CompoundTag nbttagcompound;
+         label43:
+         {
+@@ -0,0 +0,0 @@ public class RegionFileStorage implements AutoCloseable {
+ 
+             try {
+                 NbtIo.write(nbt, (DataOutput) dataoutputstream);
++                regionfile.setOversized(pos.x, pos.z, false); // Paper - We don't do this anymore, mojang stores differently, but clear old meta flag if it exists to get rid of our own meta file once last oversized is gone
+                 // Paper start - don't write garbage data to disk if writing serialization fails
+                 dataoutputstream.close(); // Only write if successful
+             } catch (final RegionFileSizeException e) {

patches/server/Entity-Activation-Range-2.0.patch

@@ -0,0 +1,812 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Aikar <aikar@aikar.co>
+Date: Fri, 13 May 2016 01:38:06 -0400
+Subject: [PATCH] Entity Activation Range 2.0
+
+Optimizes performance of Activation Range
+
+Adds many new configurations and a new wake up inactive system
+
+Fixes and adds new Immunities to improve gameplay behavior
+
+Adds water Mobs to activation range config and nerfs fish
+Adds flying monsters to control ghast and phantoms
+Adds villagers as separate config
+
+== AT ==
+public net.minecraft.world.entity.Entity isInsidePortal
+
+diff --git a/src/main/java/net/minecraft/server/level/ServerLevel.java b/src/main/java/net/minecraft/server/level/ServerLevel.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/server/level/ServerLevel.java
++++ b/src/main/java/net/minecraft/server/level/ServerLevel.java
+@@ -0,0 +0,0 @@ package net.minecraft.server.level;
+ 
+ import com.google.common.annotations.VisibleForTesting;
+ import co.aikar.timings.TimingHistory; // Paper
+-import co.aikar.timings.Timings; // Paper
+ import com.google.common.collect.Lists;
+ import com.mojang.datafixers.DataFixer;
+ import com.mojang.datafixers.util.Pair;
+@@ -0,0 +0,0 @@ public class ServerLevel extends Level implements WorldGenLevel {
+         ++TimingHistory.entityTicks; // Paper - timings
+         // Spigot start
+         co.aikar.timings.Timing timer; // Paper
+-        if (!org.spigotmc.ActivationRange.checkIfActive(entity)) {
++        /*if (!org.spigotmc.ActivationRange.checkIfActive(entity)) { // Paper - comment out - EAR 2, reimplement below
+             entity.tickCount++;
+             timer = entity.getType().inactiveTickTimer.startTiming(); try { // Paper - timings
+             entity.inactiveTick();
+             } finally { timer.stopTiming(); } // Paper
+             return;
+-        }
++        }*/ // Paper - comment out EAR 2
+         // Spigot end
+         // Paper start- timings
+-        TimingHistory.activatedEntityTicks++;
+-        timer = entity.getVehicle() != null ? entity.getType().passengerTickTimer.startTiming() : entity.getType().tickTimer.startTiming();
++        final boolean isActive = org.spigotmc.ActivationRange.checkIfActive(entity);
++        timer = isActive ? entity.getType().tickTimer.startTiming() : entity.getType().inactiveTickTimer.startTiming(); // Paper
+         try {
+         // Paper end - timings
+         entity.setOldPosAndRot();
+@@ -0,0 +0,0 @@ public class ServerLevel extends Level implements WorldGenLevel {
+             return BuiltInRegistries.ENTITY_TYPE.getKey(entity.getType()).toString();
+         });
+         gameprofilerfiller.incrementCounter("tickNonPassenger");
++        if (isActive) { // Paper - EAR 2
++            TimingHistory.activatedEntityTicks++;
+         entity.tick();
+         entity.postTick(); // CraftBukkit
++        } else { entity.inactiveTick(); } // Paper - EAR 2
+         this.getProfiler().pop();
++        } finally { timer.stopTiming(); } // Paper - timings
+         Iterator iterator = entity.getPassengers().iterator();
+ 
+         while (iterator.hasNext()) {
+@@ -0,0 +0,0 @@ public class ServerLevel extends Level implements WorldGenLevel {
+ 
+             this.tickPassenger(entity, entity1);
+         }
+-        } finally { timer.stopTiming(); } // Paper - timings
++        // } finally { timer.stopTiming(); } // Paper - timings - move up
+ 
+     }
+ 
+     private void tickPassenger(Entity vehicle, Entity passenger) {
+         if (!passenger.isRemoved() && passenger.getVehicle() == vehicle) {
+             if (passenger instanceof Player || this.entityTickList.contains(passenger)) {
++                // Paper - EAR 2
++                final boolean isActive = org.spigotmc.ActivationRange.checkIfActive(passenger);
++                co.aikar.timings.Timing timer = isActive ? passenger.getType().passengerTickTimer.startTiming() : passenger.getType().passengerInactiveTickTimer.startTiming(); // Paper
++                try {
++                // Paper end
+                 passenger.setOldPosAndRot();
+                 ++passenger.tickCount;
+                 ProfilerFiller gameprofilerfiller = this.getProfiler();
+@@ -0,0 +0,0 @@ public class ServerLevel extends Level implements WorldGenLevel {
+                     return BuiltInRegistries.ENTITY_TYPE.getKey(passenger.getType()).toString();
+                 });
+                 gameprofilerfiller.incrementCounter("tickPassenger");
++                // Paper start - EAR 2
++                if (isActive) {
+                 passenger.rideTick();
+                 passenger.postTick(); // CraftBukkit
++                } else {
++                    passenger.setDeltaMovement(Vec3.ZERO);
++                    passenger.inactiveTick();
++                    // copied from inside of if (isPassenger()) of passengerTick, but that ifPassenger is unnecessary
++                    vehicle.positionRider(passenger);
++                }
++                // Paper end - EAR 2
+                 gameprofilerfiller.pop();
+                 Iterator iterator = passenger.getPassengers().iterator();
+ 
+@@ -0,0 +0,0 @@ public class ServerLevel extends Level implements WorldGenLevel {
+                     this.tickPassenger(passenger, entity2);
+                 }
+ 
++            } finally { timer.stopTiming(); }// Paper - EAR2 timings
+             }
+         } else {
+             passenger.stopRiding();
+diff --git a/src/main/java/net/minecraft/world/entity/Entity.java b/src/main/java/net/minecraft/world/entity/Entity.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/world/entity/Entity.java
++++ b/src/main/java/net/minecraft/world/entity/Entity.java
+@@ -0,0 +0,0 @@ public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess
+     // Spigot end
+     protected int numCollisions = 0; // Paper - Cap entity collisions
+     public boolean fromNetherPortal; // Paper - Add option to nerf pigmen from nether portals
++    public long activatedImmunityTick = Integer.MIN_VALUE; // Paper - EAR
++    public boolean isTemporarilyActive; // Paper - EAR
+     public boolean spawnedViaMobSpawner; // Paper - Yes this name is similar to above, upstream took the better one
+     // Paper start - Entity origin API
+     @javax.annotation.Nullable
+@@ -0,0 +0,0 @@ public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess
+         } else {
+             this.wasOnFire = this.isOnFire();
+             if (movementType == MoverType.PISTON) {
++                this.activatedTick = Math.max(this.activatedTick, MinecraftServer.currentTick + 20); // Paper
++                this.activatedImmunityTick = Math.max(this.activatedImmunityTick, MinecraftServer.currentTick + 20);   // Paper
+                 movement = this.limitPistonMovement(movement);
+                 if (movement.equals(Vec3.ZERO)) {
+                     return;
+@@ -0,0 +0,0 @@ public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess
+                 this.stuckSpeedMultiplier = Vec3.ZERO;
+                 this.setDeltaMovement(Vec3.ZERO);
+             }
++            // Paper start - ignore movement changes while inactive.
++            if (isTemporarilyActive && !(this instanceof ItemEntity) && movement == getDeltaMovement() && movementType == MoverType.SELF) {
++                setDeltaMovement(Vec3.ZERO);
++                this.level.getProfiler().pop();
++                return;
++            }
++            // Paper end
+ 
+             movement = this.maybeBackOffFromEdge(movement, movementType);
+             Vec3 vec3d1 = this.collide(movement);
+diff --git a/src/main/java/net/minecraft/world/entity/Mob.java b/src/main/java/net/minecraft/world/entity/Mob.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/world/entity/Mob.java
++++ b/src/main/java/net/minecraft/world/entity/Mob.java
+@@ -0,0 +0,0 @@ public abstract class Mob extends LivingEntity implements EquipmentUser, Targeti
+         return this.lookControl;
+     }
+ 
++    // Paper start
++    @Override
++    public void inactiveTick() {
++        super.inactiveTick();
++        if (this.goalSelector.inactiveTick()) {
++            this.goalSelector.tick();
++        }
++        if (this.targetSelector.inactiveTick()) {
++            this.targetSelector.tick();
++        }
++    }
++    // Paper end
++
+     public MoveControl getMoveControl() {
+         Entity entity = this.getControlledVehicle();
+ 
+diff --git a/src/main/java/net/minecraft/world/entity/PathfinderMob.java b/src/main/java/net/minecraft/world/entity/PathfinderMob.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/world/entity/PathfinderMob.java
++++ b/src/main/java/net/minecraft/world/entity/PathfinderMob.java
+@@ -0,0 +0,0 @@ public abstract class PathfinderMob extends Mob {
+     }
+ 
+     public org.bukkit.craftbukkit.entity.CraftCreature getBukkitCreature() { return (org.bukkit.craftbukkit.entity.CraftCreature) super.getBukkitEntity(); } // Paper
++    public BlockPos movingTarget = null; public BlockPos getMovingTarget() { return movingTarget; } // Paper
+ 
+     public float getWalkTargetValue(BlockPos pos) {
+         return this.getWalkTargetValue(pos, this.level());
+diff --git a/src/main/java/net/minecraft/world/entity/ai/goal/GoalSelector.java b/src/main/java/net/minecraft/world/entity/ai/goal/GoalSelector.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/world/entity/ai/goal/GoalSelector.java
++++ b/src/main/java/net/minecraft/world/entity/ai/goal/GoalSelector.java
+@@ -0,0 +0,0 @@ public class GoalSelector {
+     private final Set<WrappedGoal> availableGoals = new ObjectLinkedOpenHashSet<>();
+     private final Supplier<ProfilerFiller> profiler;
+     private final EnumSet<Goal.Flag> disabledFlags = EnumSet.noneOf(Goal.Flag.class);
++    private int curRate;
+ 
+     public GoalSelector(Supplier<ProfilerFiller> profiler) {
+         this.profiler = profiler;
+@@ -0,0 +0,0 @@ public class GoalSelector {
+         this.availableGoals.removeIf(goal -> predicate.test(goal.getGoal()));
+     }
+ 
++    // Paper start
++    public boolean inactiveTick() {
++        this.curRate++;
++        return this.curRate % 3 == 0; // TODO newGoalRate was already unused in 1.20.4, check if this is correct
++    }
++    public boolean hasTasks() {
++        for (WrappedGoal task : this.availableGoals) {
++            if (task.isRunning()) {
++                return true;
++            }
++        }
++        return false;
++    }
++    // Paper end
+     public void removeGoal(Goal goal) {
+         for (WrappedGoal wrappedGoal : this.availableGoals) {
+             if (wrappedGoal.getGoal() == goal && wrappedGoal.isRunning()) {
+diff --git a/src/main/java/net/minecraft/world/entity/ai/goal/MoveToBlockGoal.java b/src/main/java/net/minecraft/world/entity/ai/goal/MoveToBlockGoal.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/world/entity/ai/goal/MoveToBlockGoal.java
++++ b/src/main/java/net/minecraft/world/entity/ai/goal/MoveToBlockGoal.java
+@@ -0,0 +0,0 @@ public abstract class MoveToBlockGoal extends Goal {
+     public MoveToBlockGoal(PathfinderMob mob, double speed, int range) {
+         this(mob, speed, range, 1);
+     }
++    // Paper start - activation range improvements
++    @Override
++    public void stop() {
++        super.stop();
++        this.blockPos = BlockPos.ZERO;
++        this.mob.movingTarget = null;
++    }
++    // Paper end
+ 
+     public MoveToBlockGoal(PathfinderMob mob, double speed, int range, int maxYDifference) {
+         this.mob = mob;
+@@ -0,0 +0,0 @@ public abstract class MoveToBlockGoal extends Goal {
+                         mutableBlockPos.setWithOffset(blockPos, m, k - 1, n);
+                         if (this.mob.isWithinRestriction(mutableBlockPos) && this.isValidTarget(this.mob.level(), mutableBlockPos)) {
+                             this.blockPos = mutableBlockPos;
++                            this.mob.movingTarget = mutableBlockPos == BlockPos.ZERO ? null : mutableBlockPos.immutable(); // Paper
+                             return true;
+                         }
+                     }
+diff --git a/src/main/java/net/minecraft/world/entity/npc/Villager.java b/src/main/java/net/minecraft/world/entity/npc/Villager.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/world/entity/npc/Villager.java
++++ b/src/main/java/net/minecraft/world/entity/npc/Villager.java
+@@ -0,0 +0,0 @@ public class Villager extends AbstractVillager implements ReputationEventHandler
+     @Override
+     public void inactiveTick() {
+         // SPIGOT-3874, SPIGOT-3894, SPIGOT-3846, SPIGOT-5286 :(
+-        if (this.level().spigotConfig.tickInactiveVillagers && this.isEffectiveAi()) {
+-            this.customServerAiStep();
++        // Paper start
++        if (this.getUnhappyCounter() > 0) {
++            this.setUnhappyCounter(this.getUnhappyCounter() - 1);
+         }
++        if (this.isEffectiveAi()) {
++            if (this.level().spigotConfig.tickInactiveVillagers) {
++                this.customServerAiStep();
++            } else {
++                this.customServerAiStep(true);
++            }
++        }
++        maybeDecayGossip();
++        // Paper end
++
+         super.inactiveTick();
+     }
+     // Spigot End
+ 
+     @Override
++    @Deprecated // Paper
+     protected void customServerAiStep() {
++        // Paper start
++        this.customServerAiStep(false);
++    }
++    protected void customServerAiStep(final boolean inactive) {
++        // Paper end
+         this.level().getProfiler().push("villagerBrain");
+-        this.getBrain().tick((ServerLevel) this.level(), this);
++        if (!inactive) this.getBrain().tick((ServerLevel) this.level(), this); // Paper
+         this.level().getProfiler().pop();
+         if (this.assignProfessionWhenSpawned) {
+             this.assignProfessionWhenSpawned = false;
+@@ -0,0 +0,0 @@ public class Villager extends AbstractVillager implements ReputationEventHandler
+             this.lastTradedPlayer = null;
+         }
+ 
+-        if (!this.isNoAi() && this.random.nextInt(100) == 0) {
++        if (!inactive && !this.isNoAi() && this.random.nextInt(100) == 0) { // Paper
+             Raid raid = ((ServerLevel) this.level()).getRaidAt(this.blockPosition());
+ 
+             if (raid != null && raid.isActive() && !raid.isOver()) {
+@@ -0,0 +0,0 @@ public class Villager extends AbstractVillager implements ReputationEventHandler
+         if (this.getVillagerData().getProfession() == VillagerProfession.NONE && this.isTrading()) {
+             this.stopTrading();
+         }
++        if (inactive) return; // Paper
+ 
+         super.customServerAiStep();
+     }
+diff --git a/src/main/java/net/minecraft/world/entity/vehicle/MinecartHopper.java b/src/main/java/net/minecraft/world/entity/vehicle/MinecartHopper.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/world/entity/vehicle/MinecartHopper.java
++++ b/src/main/java/net/minecraft/world/entity/vehicle/MinecartHopper.java
+@@ -0,0 +0,0 @@ public class MinecartHopper extends AbstractMinecartContainer implements Hopper
+         if (bl != this.isEnabled()) {
+             this.setEnabled(bl);
+         }
++        this.immunize();  // Paper
+     }
+ 
+     public boolean isEnabled() {
+@@ -0,0 +0,0 @@ public class MinecartHopper extends AbstractMinecartContainer implements Hopper
+ 
+     public boolean suckInItems() {
+         if (HopperBlockEntity.suckInItems(this.level(), this)) {
++            this.immunize();  // Paper
+             return true;
+         } else {
+             for (ItemEntity itemEntity : this.level()
+                 .getEntitiesOfClass(ItemEntity.class, this.getBoundingBox().inflate(0.25, 0.0, 0.25), EntitySelector.ENTITY_STILL_ALIVE)) {
+                 if (HopperBlockEntity.addItem(this, itemEntity)) {
++                    this.immunize();  // Paper
+                     return true;
+                 }
+             }
+@@ -0,0 +0,0 @@ public class MinecartHopper extends AbstractMinecartContainer implements Hopper
+     public AbstractContainerMenu createMenu(int syncId, Inventory playerInventory) {
+         return new HopperMenu(syncId, playerInventory, this);
+     }
++
++    // Paper start
++    public void immunize() {
++        this.activatedImmunityTick = Math.max(this.activatedImmunityTick, net.minecraft.server.MinecraftServer.currentTick + 20);
++    }
++    // Paper end
++
+ }
+diff --git a/src/main/java/net/minecraft/world/level/Level.java b/src/main/java/net/minecraft/world/level/Level.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/world/level/Level.java
++++ b/src/main/java/net/minecraft/world/level/Level.java
+@@ -0,0 +0,0 @@ public abstract class Level implements LevelAccessor, AutoCloseable {
+     public Map<BlockPos, BlockEntity> capturedTileEntities = new java.util.LinkedHashMap<>(); // Paper - Retain block place order when capturing blockstates
+     public List<ItemEntity> captureDrops;
+     public final it.unimi.dsi.fastutil.objects.Object2LongOpenHashMap<SpawnCategory> ticksPerSpawnCategory = new it.unimi.dsi.fastutil.objects.Object2LongOpenHashMap<>();
++    // Paper start
++    public int wakeupInactiveRemainingAnimals;
++    public int wakeupInactiveRemainingFlying;
++    public int wakeupInactiveRemainingMonsters;
++    public int wakeupInactiveRemainingVillagers;
++    // Paper end
+     public boolean populating;
+     public final org.spigotmc.SpigotWorldConfig spigotConfig; // Spigot
+     // Paper start - add paper world config
+diff --git a/src/main/java/net/minecraft/world/level/block/piston/PistonMovingBlockEntity.java b/src/main/java/net/minecraft/world/level/block/piston/PistonMovingBlockEntity.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/world/level/block/piston/PistonMovingBlockEntity.java
++++ b/src/main/java/net/minecraft/world/level/block/piston/PistonMovingBlockEntity.java
+@@ -0,0 +0,0 @@ public class PistonMovingBlockEntity extends BlockEntity {
+                                 }
+ 
+                                 entity.setDeltaMovement(e, g, h);
++                                // Paper - EAR items stuck in in slime pushed by a piston
++                                entity.activatedTick = Math.max(entity.activatedTick, net.minecraft.server.MinecraftServer.currentTick + 10);
++                                entity.activatedImmunityTick = Math.max(entity.activatedImmunityTick, net.minecraft.server.MinecraftServer.currentTick + 10);
++                                // Paper end
+                                 break;
+                             }
+                         }
+diff --git a/src/main/java/org/spigotmc/ActivationRange.java b/src/main/java/org/spigotmc/ActivationRange.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/org/spigotmc/ActivationRange.java
++++ b/src/main/java/org/spigotmc/ActivationRange.java
+@@ -0,0 +0,0 @@
+ package org.spigotmc;
+ 
++import net.minecraft.core.BlockPos;
+ import net.minecraft.server.MinecraftServer;
++import net.minecraft.server.level.ServerChunkCache;
+ import net.minecraft.world.entity.Entity;
+ import net.minecraft.world.entity.ExperienceOrb;
++import net.minecraft.world.entity.FlyingMob;
+ import net.minecraft.world.entity.LightningBolt;
+ import net.minecraft.world.entity.LivingEntity;
++import net.minecraft.world.entity.Mob;
+ import net.minecraft.world.entity.PathfinderMob;
++import net.minecraft.world.entity.ai.Brain;
+ import net.minecraft.world.entity.ambient.AmbientCreature;
+ import net.minecraft.world.entity.animal.Animal;
++import net.minecraft.world.entity.animal.Bee;
+ import net.minecraft.world.entity.animal.Sheep;
++import net.minecraft.world.entity.animal.WaterAnimal;
++import net.minecraft.world.entity.animal.horse.Llama;
+ import net.minecraft.world.entity.boss.EnderDragonPart;
+ import net.minecraft.world.entity.boss.enderdragon.EndCrystal;
+ import net.minecraft.world.entity.boss.enderdragon.EnderDragon;
+ import net.minecraft.world.entity.boss.wither.WitherBoss;
+ import net.minecraft.world.entity.item.PrimedTnt;
+ import net.minecraft.world.entity.monster.Creeper;
+-import net.minecraft.world.entity.monster.Monster;
+-import net.minecraft.world.entity.monster.Slime;
++import net.minecraft.world.entity.monster.Enemy;
++import net.minecraft.world.entity.monster.Pillager;
+ import net.minecraft.world.entity.npc.Villager;
+ import net.minecraft.world.entity.player.Player;
+ import net.minecraft.world.entity.projectile.AbstractArrow;
+ import net.minecraft.world.entity.projectile.AbstractHurtingProjectile;
++import net.minecraft.world.entity.projectile.EyeOfEnder;
+ import net.minecraft.world.entity.projectile.FireworkRocketEntity;
+ import net.minecraft.world.entity.projectile.ThrowableProjectile;
+ import net.minecraft.world.entity.projectile.ThrownTrident;
+ import net.minecraft.world.entity.raid.Raider;
++import co.aikar.timings.MinecraftTimings;
++import net.minecraft.world.entity.schedule.Activity;
+ import net.minecraft.world.level.Level;
+ import net.minecraft.world.phys.AABB;
+-import co.aikar.timings.MinecraftTimings;
+ 
+ public class ActivationRange
+ {
+@@ -0,0 +0,0 @@ public class ActivationRange
+ 
+         AABB boundingBox = new AABB( 0, 0, 0, 0, 0, 0 );
+     }
++    // Paper start
++
++    static Activity[] VILLAGER_PANIC_IMMUNITIES = {
++        Activity.HIDE,
++        Activity.PRE_RAID,
++        Activity.RAID,
++        Activity.PANIC
++    };
++
++    private static int checkInactiveWakeup(Entity entity) {
++        Level world = entity.level();
++        SpigotWorldConfig config = world.spigotConfig;
++        long inactiveFor = MinecraftServer.currentTick - entity.activatedTick;
++        if (entity.activationType == ActivationType.VILLAGER) {
++            if (inactiveFor > config.wakeUpInactiveVillagersEvery && world.wakeupInactiveRemainingVillagers > 0) {
++                world.wakeupInactiveRemainingVillagers--;
++                return config.wakeUpInactiveVillagersFor;
++            }
++        } else if (entity.activationType == ActivationType.ANIMAL) {
++            if (inactiveFor > config.wakeUpInactiveAnimalsEvery && world.wakeupInactiveRemainingAnimals > 0) {
++                world.wakeupInactiveRemainingAnimals--;
++                return config.wakeUpInactiveAnimalsFor;
++            }
++        } else if (entity.activationType == ActivationType.FLYING_MONSTER) {
++            if (inactiveFor > config.wakeUpInactiveFlyingEvery && world.wakeupInactiveRemainingFlying > 0) {
++                world.wakeupInactiveRemainingFlying--;
++                return config.wakeUpInactiveFlyingFor;
++            }
++        } else if (entity.activationType == ActivationType.MONSTER || entity.activationType == ActivationType.RAIDER) {
++            if (inactiveFor > config.wakeUpInactiveMonstersEvery && world.wakeupInactiveRemainingMonsters > 0) {
++                world.wakeupInactiveRemainingMonsters--;
++                return config.wakeUpInactiveMonstersFor;
++            }
++        }
++        return -1;
++    }
++    // Paper end
+ 
+     static AABB maxBB = new AABB( 0, 0, 0, 0, 0, 0 );
+ 
+@@ -0,0 +0,0 @@ public class ActivationRange
+      */
+     public static ActivationType initializeEntityActivationType(Entity entity)
+     {
++        if (entity instanceof WaterAnimal) { return ActivationType.WATER; } // Paper
++        else if (entity instanceof Villager) { return ActivationType.VILLAGER; } // Paper
++        else if (entity instanceof FlyingMob && entity instanceof Enemy) { return ActivationType.FLYING_MONSTER; } // Paper - doing & Monster incase Flying no longer includes monster in future
+         if ( entity instanceof Raider )
+         {
+             return ActivationType.RAIDER;
+-        } else if ( entity instanceof Monster || entity instanceof Slime )
++        } else if ( entity instanceof Enemy ) // Paper - correct monster check
+         {
+             return ActivationType.MONSTER;
+         } else if ( entity instanceof PathfinderMob || entity instanceof AmbientCreature )
+@@ -0,0 +0,0 @@ public class ActivationRange
+      */
+     public static boolean initializeEntityActivationState(Entity entity, SpigotWorldConfig config)
+     {
+-        if ( ( entity.activationType == ActivationType.MISC && config.miscActivationRange == 0 )
+-                || ( entity.activationType == ActivationType.RAIDER && config.raiderActivationRange == 0 )
+-                || ( entity.activationType == ActivationType.ANIMAL && config.animalActivationRange == 0 )
+-                || ( entity.activationType == ActivationType.MONSTER && config.monsterActivationRange == 0 )
++        if ( ( entity.activationType == ActivationType.MISC && config.miscActivationRange <= 0 )
++                || ( entity.activationType == ActivationType.RAIDER && config.raiderActivationRange <= 0 )
++                || ( entity.activationType == ActivationType.ANIMAL && config.animalActivationRange <= 0 )
++                || ( entity.activationType == ActivationType.MONSTER && config.monsterActivationRange <= 0 )
++                || ( entity.activationType == ActivationType.VILLAGER && config.villagerActivationRange <= 0 ) // Paper
++                || ( entity.activationType == ActivationType.WATER && config.waterActivationRange <= 0 ) // Paper
++                || ( entity.activationType == ActivationType.FLYING_MONSTER && config.flyingMonsterActivationRange <= 0 ) // Paper
++                || entity instanceof EyeOfEnder // Paper
+                 || entity instanceof Player
+                 || entity instanceof ThrowableProjectile
+                 || entity instanceof EnderDragon
+@@ -0,0 +0,0 @@ public class ActivationRange
+         final int raiderActivationRange = world.spigotConfig.raiderActivationRange;
+         final int animalActivationRange = world.spigotConfig.animalActivationRange;
+         final int monsterActivationRange = world.spigotConfig.monsterActivationRange;
++        // Paper start
++        final int waterActivationRange = world.spigotConfig.waterActivationRange;
++        final int flyingActivationRange = world.spigotConfig.flyingMonsterActivationRange;
++        final int villagerActivationRange = world.spigotConfig.villagerActivationRange;
++        world.wakeupInactiveRemainingAnimals = Math.min(world.wakeupInactiveRemainingAnimals + 1, world.spigotConfig.wakeUpInactiveAnimals);
++        world.wakeupInactiveRemainingVillagers = Math.min(world.wakeupInactiveRemainingVillagers + 1, world.spigotConfig.wakeUpInactiveVillagers);
++        world.wakeupInactiveRemainingMonsters = Math.min(world.wakeupInactiveRemainingMonsters + 1, world.spigotConfig.wakeUpInactiveMonsters);
++        world.wakeupInactiveRemainingFlying = Math.min(world.wakeupInactiveRemainingFlying + 1, world.spigotConfig.wakeUpInactiveFlying);
++        final ServerChunkCache chunkProvider = (ServerChunkCache) world.getChunkSource();
++        // Paper end
+ 
+         int maxRange = Math.max( monsterActivationRange, animalActivationRange );
+         maxRange = Math.max( maxRange, raiderActivationRange );
+         maxRange = Math.max( maxRange, miscActivationRange );
++        // Paper start
++        maxRange = Math.max( maxRange, flyingActivationRange );
++        maxRange = Math.max( maxRange, waterActivationRange );
++        maxRange = Math.max( maxRange, villagerActivationRange );
++        // Paper end
+         maxRange = Math.min( ( world.spigotConfig.simulationDistance << 4 ) - 8, maxRange );
+ 
+         for ( Player player : world.players() )
+@@ -0,0 +0,0 @@ public class ActivationRange
+                 continue;
+             }
+ 
+-            ActivationRange.maxBB = player.getBoundingBox().inflate( maxRange, 256, maxRange );
+-            ActivationType.MISC.boundingBox = player.getBoundingBox().inflate( miscActivationRange, 256, miscActivationRange );
+-            ActivationType.RAIDER.boundingBox = player.getBoundingBox().inflate( raiderActivationRange, 256, raiderActivationRange );
+-            ActivationType.ANIMAL.boundingBox = player.getBoundingBox().inflate( animalActivationRange, 256, animalActivationRange );
+-            ActivationType.MONSTER.boundingBox = player.getBoundingBox().inflate( monsterActivationRange, 256, monsterActivationRange );
++            // Paper start
++            int worldHeight = world.getHeight();
++            ActivationRange.maxBB = player.getBoundingBox().inflate( maxRange, worldHeight, maxRange );
++            ActivationType.MISC.boundingBox = player.getBoundingBox().inflate( miscActivationRange, worldHeight, miscActivationRange );
++            ActivationType.RAIDER.boundingBox = player.getBoundingBox().inflate( raiderActivationRange, worldHeight, raiderActivationRange );
++            ActivationType.ANIMAL.boundingBox = player.getBoundingBox().inflate( animalActivationRange, worldHeight, animalActivationRange );
++            ActivationType.MONSTER.boundingBox = player.getBoundingBox().inflate( monsterActivationRange, worldHeight, monsterActivationRange );
++            ActivationType.WATER.boundingBox = player.getBoundingBox().inflate( waterActivationRange, worldHeight, waterActivationRange );
++            ActivationType.FLYING_MONSTER.boundingBox = player.getBoundingBox().inflate( flyingActivationRange, worldHeight, flyingActivationRange );
++            ActivationType.VILLAGER.boundingBox = player.getBoundingBox().inflate( villagerActivationRange, worldHeight, villagerActivationRange );
++            // Paper end
+ 
+-            world.getEntities().get(ActivationRange.maxBB, ActivationRange::activateEntity);
++            // Paper start
++            java.util.List<Entity> entities = world.getEntities((Entity)null, ActivationRange.maxBB, null);
++            boolean tickMarkers = world.paperConfig().entities.markers.tick; // Paper - Configurable marker ticking
++            for (Entity entity : entities) {
++                // Paper start - Configurable marker ticking
++                if (!tickMarkers && entity instanceof net.minecraft.world.entity.Marker) {
++                    continue;
++                }
++                // Paper end - Configurable marker ticking
++                ActivationRange.activateEntity(entity);
++            }
++            // Paper end
+         }
+         MinecraftTimings.entityActivationCheckTimer.stopTiming();
+     }
+@@ -0,0 +0,0 @@ public class ActivationRange
+      * @param entity
+      * @return
+      */
+-    public static boolean checkEntityImmunities(Entity entity)
++    public static int checkEntityImmunities(Entity entity) // Paper - return # of ticks to get immunity
+     {
++        // Paper start
++        SpigotWorldConfig config = entity.level().spigotConfig;
++        int inactiveWakeUpImmunity = checkInactiveWakeup(entity);
++        if (inactiveWakeUpImmunity > -1) {
++            return inactiveWakeUpImmunity;
++        }
++        if (entity.getRemainingFireTicks() > 0) {
++            return 2;
++        }
++        if (entity.activatedImmunityTick >= MinecraftServer.currentTick) {
++            return 1;
++        }
++        long inactiveFor = MinecraftServer.currentTick - entity.activatedTick;
++        // Paper end
+         // quick checks.
+-        if ( entity.wasTouchingWater || entity.getRemainingFireTicks() > 0 )
++        if ( (entity.activationType != ActivationType.WATER && entity.wasTouchingWater && entity.isPushedByFluid()) ) // Paper
+         {
+-            return true;
++            return 100; // Paper
++        }
++        // Paper start
++        if ( !entity.onGround() || entity.getDeltaMovement().horizontalDistanceSqr() > 9.999999747378752E-6D )
++        {
++            return 100;
+         }
++        // Paper end
+         if ( !( entity instanceof AbstractArrow ) )
+         {
+-            if ( !entity.onGround() || !entity.passengers.isEmpty() || entity.isPassenger() )
++            if ( (!entity.onGround() && !(entity instanceof FlyingMob)) ) // Paper - remove passengers logic
+             {
+-                return true;
++                return 10; // Paper
+             }
+         } else if ( !( (AbstractArrow) entity ).inGround )
+         {
+-            return true;
++            return 1; // Paper
+         }
+         // special cases.
+         if ( entity instanceof LivingEntity )
+         {
+             LivingEntity living = (LivingEntity) entity;
+-            if ( /*TODO: Missed mapping? living.attackTicks > 0 || */ living.hurtTime > 0 || living.activeEffects.size() > 0 )
++            if ( living.onClimbable() || living.jumping || living.hurtTime > 0 || living.activeEffects.size() > 0 || living.isFreezing()) // Paper
+             {
+-                return true;
++                return 1; // Paper
+             }
+-            if ( entity instanceof PathfinderMob && ( (PathfinderMob) entity ).getTarget() != null )
++            if ( entity instanceof Mob && ((Mob) entity ).getTarget() != null) // Paper
+             {
+-                return true;
++                return 20; // Paper
++            }
++            // Paper start
++            if (entity instanceof Bee) {
++                Bee bee = (Bee)entity;
++                BlockPos movingTarget = bee.getMovingTarget();
++                if (bee.isAngry() ||
++                    (bee.getHivePos() != null && bee.getHivePos().equals(movingTarget)) ||
++                    (bee.getSavedFlowerPos() != null && bee.getSavedFlowerPos().equals(movingTarget))
++                ) {
++                    return 20;
++                }
+             }
+-            if ( entity instanceof Villager && ( (Villager) entity ).canBreed() )
++            if ( entity instanceof Villager ) {
++                Brain<Villager> behaviorController = ((Villager) entity).getBrain();
++
++                if (config.villagersActiveForPanic) {
++                    for (Activity activity : VILLAGER_PANIC_IMMUNITIES) {
++                        if (behaviorController.isActive(activity)) {
++                            return 20*5;
++                        }
++                    }
++                }
++
++                if (config.villagersWorkImmunityAfter > 0 && inactiveFor >= config.villagersWorkImmunityAfter) {
++                    if (behaviorController.isActive(Activity.WORK)) {
++                        return config.villagersWorkImmunityFor;
++                    }
++                }
++            }
++            if ( entity instanceof Llama && ( (Llama) entity ).inCaravan() )
+             {
+-                return true;
++                return 1;
+             }
++            // Paper end
+             if ( entity instanceof Animal )
+             {
+                 Animal animal = (Animal) entity;
+                 if ( animal.isBaby() || animal.isInLove() )
+                 {
+-                    return true;
++                    return 5; // Paper
+                 }
+                 if ( entity instanceof Sheep && ( (Sheep) entity ).isSheared() )
+                 {
+-                    return true;
++                    return 1; // Paper
+                 }
+             }
+             if (entity instanceof Creeper && ((Creeper) entity).isIgnited()) { // isExplosive
+-                return true;
++                return 20; // Paper
++            }
++            // Paper start
++            if (entity instanceof Mob && ((Mob) entity).targetSelector.hasTasks() ) {
++                return 0;
+             }
++            if (entity instanceof Pillager) {
++                Pillager pillager = (Pillager) entity;
++                // TODO:?
++            }
++            // Paper end
+         }
+         // SPIGOT-6644: Otherwise the target refresh tick will be missed
+         if (entity instanceof ExperienceOrb) {
+-            return true;
++            return 20; // Paper
+         }
+-        return false;
++        return -1; // Paper
+     }
+ 
+     /**
+@@ -0,0 +0,0 @@ public class ActivationRange
+         if ( entity instanceof FireworkRocketEntity ) {
+             return true;
+         }
++        // Paper start - special case always immunities
++        // immunize brand new entities, dead entities, and portal scenarios
++        if (entity.defaultActivationState || entity.tickCount < 20*10 || !entity.isAlive() || entity.isInsidePortal || entity.portalCooldown > 0) {
++            return true;
++        }
++        // immunize leashed entities
++        if (entity instanceof Mob && ((Mob)entity).getLeashHolder() instanceof Player) {
++            return true;
++        }
++        // Paper end
+ 
+-        boolean isActive = entity.activatedTick >= MinecraftServer.currentTick || entity.defaultActivationState;
++        boolean isActive = entity.activatedTick >= MinecraftServer.currentTick;
++        entity.isTemporarilyActive = false; // Paper
+ 
+         // Should this entity tick?
+         if ( !isActive )
+@@ -0,0 +0,0 @@ public class ActivationRange
+             if ( ( MinecraftServer.currentTick - entity.activatedTick - 1 ) % 20 == 0 )
+             {
+                 // Check immunities every 20 ticks.
+-                if ( ActivationRange.checkEntityImmunities( entity ) )
+-                {
+-                    // Triggered some sort of immunity, give 20 full ticks before we check again.
+-                    entity.activatedTick = MinecraftServer.currentTick + 20;
++                // Paper start
++                int immunity = checkEntityImmunities(entity);
++                if (immunity >= 0) {
++                    entity.activatedTick = MinecraftServer.currentTick + immunity;
++                } else {
++                    entity.isTemporarilyActive = true;
+                 }
++                // Paper end
+                 isActive = true;
++
+             }
+             // Add a little performance juice to active entities. Skip 1/4 if not immune.
+-        } else if ( !entity.defaultActivationState && (entity.tickCount + entity.getId()) % 4 == 0 && !ActivationRange.checkEntityImmunities( entity ) ) // Paper - Ensure checking item movement is offset from Spigot's entity activation range check
++        } else if ( (entity.tickCount + entity.getId()) % 4 == 0 && ActivationRange.checkEntityImmunities( entity ) < 0 ) // Paper
+         {
+             isActive = false;
+         }
+diff --git a/src/main/java/org/spigotmc/SpigotWorldConfig.java b/src/main/java/org/spigotmc/SpigotWorldConfig.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/org/spigotmc/SpigotWorldConfig.java
++++ b/src/main/java/org/spigotmc/SpigotWorldConfig.java
+@@ -0,0 +0,0 @@ public class SpigotWorldConfig
+     public int monsterActivationRange = 32;
+     public int raiderActivationRange = 48;
+     public int miscActivationRange = 16;
++    // Paper start
++    public int flyingMonsterActivationRange = 32;
++    public int waterActivationRange = 16;
++    public int villagerActivationRange = 32;
++    public int wakeUpInactiveAnimals = 4;
++    public int wakeUpInactiveAnimalsEvery = 60*20;
++    public int wakeUpInactiveAnimalsFor = 5*20;
++    public int wakeUpInactiveMonsters = 8;
++    public int wakeUpInactiveMonstersEvery = 20*20;
++    public int wakeUpInactiveMonstersFor = 5*20;
++    public int wakeUpInactiveVillagers = 4;
++    public int wakeUpInactiveVillagersEvery = 30*20;
++    public int wakeUpInactiveVillagersFor = 5*20;
++    public int wakeUpInactiveFlying = 8;
++    public int wakeUpInactiveFlyingEvery = 10*20;
++    public int wakeUpInactiveFlyingFor = 5*20;
++    public int villagersWorkImmunityAfter = 5*20;
++    public int villagersWorkImmunityFor = 20;
++    public boolean villagersActiveForPanic = true;
++    // Paper end
+     public boolean tickInactiveVillagers = true;
+     public boolean ignoreSpectatorActivation = false;
+     private void activationRange()
+     {
++        boolean hasAnimalsConfig = config.getInt("entity-activation-range.animals", this.animalActivationRange) != this.animalActivationRange; // Paper
+         this.animalActivationRange = this.getInt( "entity-activation-range.animals", this.animalActivationRange );
+         this.monsterActivationRange = this.getInt( "entity-activation-range.monsters", this.monsterActivationRange );
+         this.raiderActivationRange = this.getInt( "entity-activation-range.raiders", this.raiderActivationRange );
+         this.miscActivationRange = this.getInt( "entity-activation-range.misc", this.miscActivationRange );
++        // Paper start
++        this.waterActivationRange = this.getInt( "entity-activation-range.water", this.waterActivationRange );
++        this.villagerActivationRange = this.getInt( "entity-activation-range.villagers", hasAnimalsConfig ? this.animalActivationRange : this.villagerActivationRange );
++        this.flyingMonsterActivationRange = this.getInt( "entity-activation-range.flying-monsters", this.flyingMonsterActivationRange );
++
++        this.wakeUpInactiveAnimals = this.getInt("entity-activation-range.wake-up-inactive.animals-max-per-tick", this.wakeUpInactiveAnimals);
++        this.wakeUpInactiveAnimalsEvery = this.getInt("entity-activation-range.wake-up-inactive.animals-every", this.wakeUpInactiveAnimalsEvery);
++        this.wakeUpInactiveAnimalsFor = this.getInt("entity-activation-range.wake-up-inactive.animals-for", this.wakeUpInactiveAnimalsFor);
++
++        this.wakeUpInactiveMonsters = this.getInt("entity-activation-range.wake-up-inactive.monsters-max-per-tick", this.wakeUpInactiveMonsters);
++        this.wakeUpInactiveMonstersEvery = this.getInt("entity-activation-range.wake-up-inactive.monsters-every", this.wakeUpInactiveMonstersEvery);
++        this.wakeUpInactiveMonstersFor = this.getInt("entity-activation-range.wake-up-inactive.monsters-for", this.wakeUpInactiveMonstersFor);
++
++        this.wakeUpInactiveVillagers = this.getInt("entity-activation-range.wake-up-inactive.villagers-max-per-tick", this.wakeUpInactiveVillagers);
++        this.wakeUpInactiveVillagersEvery = this.getInt("entity-activation-range.wake-up-inactive.villagers-every", this.wakeUpInactiveVillagersEvery);
++        this.wakeUpInactiveVillagersFor = this.getInt("entity-activation-range.wake-up-inactive.villagers-for", this.wakeUpInactiveVillagersFor);
++
++        this.wakeUpInactiveFlying = this.getInt("entity-activation-range.wake-up-inactive.flying-monsters-max-per-tick", this.wakeUpInactiveFlying);
++        this.wakeUpInactiveFlyingEvery = this.getInt("entity-activation-range.wake-up-inactive.flying-monsters-every", this.wakeUpInactiveFlyingEvery);
++        this.wakeUpInactiveFlyingFor = this.getInt("entity-activation-range.wake-up-inactive.flying-monsters-for", this.wakeUpInactiveFlyingFor);
++
++        this.villagersWorkImmunityAfter = this.getInt( "entity-activation-range.villagers-work-immunity-after", this.villagersWorkImmunityAfter );
++        this.villagersWorkImmunityFor = this.getInt( "entity-activation-range.villagers-work-immunity-for", this.villagersWorkImmunityFor );
++        this.villagersActiveForPanic = this.getBoolean( "entity-activation-range.villagers-active-for-panic", this.villagersActiveForPanic );
++        // Paper end
+         this.tickInactiveVillagers = this.getBoolean( "entity-activation-range.tick-inactive-villagers", this.tickInactiveVillagers );
+         this.ignoreSpectatorActivation = this.getBoolean( "entity-activation-range.ignore-spectators", this.ignoreSpectatorActivation );
+         this.log( "Entity Activation Range: An " + this.animalActivationRange + " / Mo " + this.monsterActivationRange + " / Ra " + this.raiderActivationRange + " / Mi " + this.miscActivationRange + " / Tiv " + this.tickInactiveVillagers + " / Isa " + this.ignoreSpectatorActivation );

patches/server/Entity-load-save-limit-per-chunk.patch

@@ -0,0 +1,58 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Jason Penilla <11360596+jpenilla@users.noreply.github.com>
+Date: Wed, 18 Nov 2020 20:52:25 -0800
+Subject: [PATCH] Entity load/save limit per chunk
+
+Adds a config option to limit the number of entities saved and loaded
+to a chunk. The default values of -1 disable the limit. Although
+defaults are only included for certain entites, this allows setting
+limits for any entity type.
+
+diff --git a/src/main/java/net/minecraft/world/entity/EntityType.java b/src/main/java/net/minecraft/world/entity/EntityType.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/world/entity/EntityType.java
++++ b/src/main/java/net/minecraft/world/entity/EntityType.java
+@@ -0,0 +0,0 @@ public class EntityType<T extends Entity> implements FeatureElement, EntityTypeT
+         final Spliterator<? extends Tag> spliterator = entityNbtList.spliterator();
+ 
+         return StreamSupport.stream(new Spliterator<Entity>() {
++            final java.util.Map<EntityType<?>, Integer> loadedEntityCounts = new java.util.HashMap<>(); // Paper - Entity load/save limit per chunk
+             public boolean tryAdvance(Consumer<? super Entity> consumer) {
+                 return spliterator.tryAdvance((nbtbase) -> {
+                     EntityType.loadEntityRecursive((CompoundTag) nbtbase, world, (entity) -> {
++                        // Paper start - Entity load/save limit per chunk
++                        final EntityType<?> entityType = entity.getType();
++                        final int saveLimit = world.paperConfig().chunks.entityPerChunkSaveLimit.getOrDefault(entityType, -1);
++                        if (saveLimit > -1) {
++                            if (this.loadedEntityCounts.getOrDefault(entityType, 0) >= saveLimit) {
++                                return null;
++                            }
++                            this.loadedEntityCounts.merge(entityType, 1, Integer::sum);
++                        }
++                        // Paper end - Entity load/save limit per chunk
+                         consumer.accept(entity);
+                         return entity;
+                     });
+diff --git a/src/main/java/net/minecraft/world/level/chunk/storage/EntityStorage.java b/src/main/java/net/minecraft/world/level/chunk/storage/EntityStorage.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/world/level/chunk/storage/EntityStorage.java
++++ b/src/main/java/net/minecraft/world/level/chunk/storage/EntityStorage.java
+@@ -0,0 +0,0 @@ public class EntityStorage implements EntityPersistentStorage<Entity> {
+         }
+ 
+         ListTag listTag = new ListTag();
++        final java.util.Map<net.minecraft.world.entity.EntityType<?>, Integer> savedEntityCounts = new java.util.HashMap<>(); // Paper - Entity load/save limit per chunk
+         entities.forEach((entity) -> { // diff here: use entities parameter
++            // Paper start - Entity load/save limit per chunk
++            final EntityType<?> entityType = entity.getType();
++            final int saveLimit = level.paperConfig().chunks.entityPerChunkSaveLimit.getOrDefault(entityType, -1);
++            if (saveLimit > -1) {
++                if (savedEntityCounts.getOrDefault(entityType, 0) >= saveLimit) {
++                    return;
++                }
++                savedEntityCounts.merge(entityType, 1, Integer::sum);
++            }
++            // Paper end - Entity load/save limit per chunk
+             CompoundTag compoundTag = new CompoundTag();
+             if (entity.save(compoundTag)) {
+                 listTag.add(compoundTag);

patches/server/Fix-World-isChunkGenerated-calls.patch

@@ -0,0 +1,243 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Spottedleaf <Spottedleaf@users.noreply.github.com>
+Date: Sat, 15 Jun 2019 08:54:33 -0700
+Subject: [PATCH] Fix World#isChunkGenerated calls
+
+Optimize World#loadChunk() too
+This patch also adds a chunk status cache on region files (note that
+its only purpose is to cache the status on DISK)
+
+diff --git a/src/main/java/net/minecraft/server/level/ChunkMap.java b/src/main/java/net/minecraft/server/level/ChunkMap.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/server/level/ChunkMap.java
++++ b/src/main/java/net/minecraft/server/level/ChunkMap.java
+@@ -0,0 +0,0 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
+     // Paper end
+ 
+     private CompletableFuture<Optional<CompoundTag>> readChunk(ChunkPos chunkPos) {
+-        return this.read(chunkPos).thenApplyAsync((optional) -> {
+-            return optional.map((nbttagcompound) -> this.upgradeChunkTag(nbttagcompound, chunkPos)); // CraftBukkit
+-        }, Util.backgroundExecutor());
++        // Paper start - Cache chunk status on disk
++        try {
++            return CompletableFuture.completedFuture(Optional.ofNullable(this.readConvertChunkSync(chunkPos)));
++        } catch (Throwable thr) {
++            return CompletableFuture.failedFuture(thr);
++        }
++        // Paper end - Cache chunk status on disk
+     }
+ 
+     // CraftBukkit start
+@@ -0,0 +0,0 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
+         // CraftBukkit end
+     }
+ 
++    // Paper start - Cache chunk status on disk
++    @Nullable
++    public CompoundTag readConvertChunkSync(ChunkPos pos) throws IOException {
++        CompoundTag nbttagcompound = this.readSync(pos);
++        if (nbttagcompound == null) {
++            return null;
++        }
++
++        nbttagcompound = this.upgradeChunkTag(nbttagcompound, pos); // CraftBukkit
++        if (nbttagcompound == null) {
++            return null;
++        }
++
++        this.updateChunkStatusOnDisk(pos, nbttagcompound);
++
++        return nbttagcompound;
++    }
++
++    public ChunkStatus getChunkStatusOnDiskIfCached(ChunkPos chunkPos) {
++        net.minecraft.world.level.chunk.storage.RegionFile regionFile = regionFileCache.getRegionFileIfLoaded(chunkPos);
++
++        return regionFile == null ? null : regionFile.getStatusIfCached(chunkPos.x, chunkPos.z);
++    }
++
++    public ChunkStatus getChunkStatusOnDisk(ChunkPos chunkPos) throws IOException {
++        net.minecraft.world.level.chunk.storage.RegionFile regionFile = regionFileCache.getRegionFile(chunkPos, true);
++
++        if (regionFile == null || !regionFileCache.chunkExists(chunkPos)) {
++            return null;
++        }
++
++        ChunkStatus status = regionFile.getStatusIfCached(chunkPos.x, chunkPos.z);
++
++        if (status != null) {
++            return status;
++        }
++
++        this.readChunk(chunkPos);
++
++        return regionFile.getStatusIfCached(chunkPos.x, chunkPos.z);
++    }
++
++    public void updateChunkStatusOnDisk(ChunkPos chunkPos, @Nullable CompoundTag compound) throws IOException {
++        net.minecraft.world.level.chunk.storage.RegionFile regionFile = regionFileCache.getRegionFile(chunkPos, false);
++
++        regionFile.setStatus(chunkPos.x, chunkPos.z, ChunkSerializer.getStatus(compound));
++    }
++
++    public ChunkAccess getUnloadingChunk(int chunkX, int chunkZ) {
++        ChunkHolder chunkHolder = io.papermc.paper.chunk.system.ChunkSystem.getUnloadingChunkHolder(this.level, chunkX, chunkZ);
++        return chunkHolder == null ? null : chunkHolder.getAvailableChunkNow();
++    }
++    // Paper end - Cache chunk status on disk
++
+     public boolean anyPlayerCloseEnoughForSpawning(ChunkPos pos) { // Paper - public
+         // Spigot start
+         return this.anyPlayerCloseEnoughForSpawning(pos, false);
+diff --git a/src/main/java/net/minecraft/world/level/chunk/storage/RegionFile.java b/src/main/java/net/minecraft/world/level/chunk/storage/RegionFile.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/world/level/chunk/storage/RegionFile.java
++++ b/src/main/java/net/minecraft/world/level/chunk/storage/RegionFile.java
+@@ -0,0 +0,0 @@ public class RegionFile implements AutoCloseable {
+     protected final RegionBitmap usedSectors;
+     public final java.util.concurrent.locks.ReentrantLock fileLock = new java.util.concurrent.locks.ReentrantLock(); // Paper
+     public final Path regionFile; // Paper
++    // Paper start - Cache chunk status
++    private final net.minecraft.world.level.chunk.ChunkStatus[] statuses = new net.minecraft.world.level.chunk.ChunkStatus[32 * 32];
++
++    private boolean closed;
++
++    // invoked on write/read
++    public void setStatus(int x, int z, net.minecraft.world.level.chunk.ChunkStatus status) {
++        if (this.closed) {
++            // We've used an invalid region file.
++            throw new IllegalStateException("RegionFile is closed");
++        }
++        this.statuses[getChunkLocation(x, z)] = status;
++    }
++
++    public net.minecraft.world.level.chunk.ChunkStatus getStatusIfCached(int x, int z) {
++        if (this.closed) {
++            // We've used an invalid region file.
++            throw new IllegalStateException("RegionFile is closed");
++        }
++        final int location = getChunkLocation(x, z);
++        return this.statuses[location];
++    }
++    // Paper end - Cache chunk status
+ 
+     public RegionFile(RegionStorageInfo storageKey, Path directory, Path path, boolean dsync) throws IOException {
+         this(storageKey, directory, path, RegionFileVersion.getCompressionFormat(), dsync); // Paper - Configurable region compression format
+@@ -0,0 +0,0 @@ public class RegionFile implements AutoCloseable {
+         return this.getOffset(pos) != 0;
+     }
+ 
++    private static int getChunkLocation(int x, int z) { return (x & 31) + (z & 31) * 32; } // Paper - Cache chunk status; OBFHELPER - sort of, mirror of logic below
+     private static int getOffsetIndex(ChunkPos pos) {
+         return pos.getRegionLocalX() + pos.getRegionLocalZ() * 32;
+     }
+@@ -0,0 +0,0 @@ public class RegionFile implements AutoCloseable {
+         synchronized (this) {
+         try {
+         // Paper end
++        this.closed = true; // Paper - Cache chunk status
+         try {
+             this.padToFullSector();
+         } finally {
+diff --git a/src/main/java/net/minecraft/world/level/chunk/storage/RegionFileStorage.java b/src/main/java/net/minecraft/world/level/chunk/storage/RegionFileStorage.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/world/level/chunk/storage/RegionFileStorage.java
++++ b/src/main/java/net/minecraft/world/level/chunk/storage/RegionFileStorage.java
+@@ -0,0 +0,0 @@ public class RegionFileStorage implements AutoCloseable {
+ 
+             try {
+                 NbtIo.write(nbt, (DataOutput) dataoutputstream);
++                regionfile.setStatus(pos.x, pos.z, ChunkSerializer.getStatus(nbt)); // Paper - Cache chunk status
+                 regionfile.setOversized(pos.x, pos.z, false); // Paper - We don't do this anymore, mojang stores differently, but clear old meta flag if it exists to get rid of our own meta file once last oversized is gone
+                 // Paper start - don't write garbage data to disk if writing serialization fails
+                 dataoutputstream.close(); // Only write if successful
+diff --git a/src/main/java/org/bukkit/craftbukkit/CraftWorld.java b/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
++++ b/src/main/java/org/bukkit/craftbukkit/CraftWorld.java
+@@ -0,0 +0,0 @@ public class CraftWorld extends CraftRegionAccessor implements World {
+ 
+     @Override
+     public boolean isChunkGenerated(int x, int z) {
++        // Paper start - Fix this method
++        if (!Bukkit.isPrimaryThread()) {
++            return java.util.concurrent.CompletableFuture.supplyAsync(() -> {
++                return CraftWorld.this.isChunkGenerated(x, z);
++            }, world.getChunkSource().mainThreadProcessor).join();
++        }
++        ChunkAccess chunk = world.getChunkSource().getChunkAtImmediately(x, z);
++        if (chunk == null) {
++            chunk = world.getChunkSource().chunkMap.getUnloadingChunk(x, z);
++        }
++        if (chunk != null) {
++            return chunk instanceof ImposterProtoChunk || chunk instanceof net.minecraft.world.level.chunk.LevelChunk;
++        }
+         try {
+-            return this.isChunkLoaded(x, z) || this.world.getChunkSource().chunkMap.read(new ChunkPos(x, z)).get().isPresent();
+-        } catch (InterruptedException | ExecutionException ex) {
++            return world.getChunkSource().chunkMap.getChunkStatusOnDisk(new ChunkPos(x, z)) == ChunkStatus.FULL;
++        } catch (java.io.IOException ex) {
++            // Paper end - Fix this method
+             throw new RuntimeException(ex);
+         }
+     }
+@@ -0,0 +0,0 @@ public class CraftWorld extends CraftRegionAccessor implements World {
+     public boolean loadChunk(int x, int z, boolean generate) {
+         org.spigotmc.AsyncCatcher.catchOp("chunk load"); // Spigot
+         warnUnsafeChunk("loading a faraway chunk", x, z); // Paper
+-        ChunkAccess chunk = this.world.getChunkSource().getChunk(x, z, generate || isChunkGenerated(x, z) ? ChunkStatus.FULL : ChunkStatus.EMPTY, true); // Paper
+-
+-        // If generate = false, but the chunk already exists, we will get this back.
+-        if (chunk instanceof ImposterProtoChunk) {
+-            // We then cycle through again to get the full chunk immediately, rather than after the ticket addition
+-            chunk = this.world.getChunkSource().getChunk(x, z, ChunkStatus.FULL, true);
+-        }
+-
+-        if (chunk instanceof net.minecraft.world.level.chunk.LevelChunk) {
+-            this.world.getChunkSource().addRegionTicket(TicketType.PLUGIN, new ChunkPos(x, z), 0, Unit.INSTANCE); // Paper
++        // Paper start - Optimize this method
++        ChunkPos chunkPos = new ChunkPos(x, z);
++        ChunkAccess immediate = world.getChunkSource().getChunkAtIfLoadedImmediately(x, z);
++        if (immediate != null) {
++            // Plugins should use plugin tickets instead of this method to keep a chunk perpetually loaded
+             return true;
+         }
+ 
+-        return false;
++        if (!generate) {
++            immediate = world.getChunkSource().chunkMap.getUnloadingChunk(x, z);
++            if (immediate != null) {
++                if (!(immediate instanceof ImposterProtoChunk) && !(immediate instanceof net.minecraft.world.level.chunk.LevelChunk)) {
++                    return false; // not full status
++                }
++                world.getChunkSource().addRegionTicket(TicketType.PLUGIN, chunkPos, 0, Unit.INSTANCE); // Paper
++                world.getChunk(x, z); // make sure we're at ticket level 32 or lower
++                return true;
++            }
++            net.minecraft.world.level.chunk.storage.RegionFile file;
++            try {
++                file = world.getChunkSource().chunkMap.regionFileCache.getRegionFile(chunkPos, false);
++            } catch (java.io.IOException ex) {
++                throw new RuntimeException(ex);
++            }
++
++            ChunkStatus status = file.getStatusIfCached(x, z);
++            if (!file.hasChunk(chunkPos) || (status != null && status != ChunkStatus.FULL)) {
++                return false;
++            }
++
++            ChunkAccess chunk = world.getChunkSource().getChunk(x, z, ChunkStatus.EMPTY, true);
++            if (!(chunk instanceof ImposterProtoChunk) && !(chunk instanceof net.minecraft.world.level.chunk.LevelChunk)) {
++                return false;
++            }
++
++            // fall through to load
++            // we do this so we do not re-read the chunk data on disk
++        }
++        world.getChunkSource().addRegionTicket(TicketType.PLUGIN, chunkPos, 0, Unit.INSTANCE); // Paper
++        world.getChunkSource().getChunk(x, z, ChunkStatus.FULL, true);
++        return true;
++        // Paper end - Optimize this method
+     }
+ 
+     @Override

patches/server/Flat-bedrock-generator-settings.patch

@@ -0,0 +1,288 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Byteflux <byte@byteflux.net>
+Date: Wed, 2 Mar 2016 02:17:54 -0600
+Subject: [PATCH] Flat bedrock generator settings
+
+== AT ==
+public net.minecraft.world.level.levelgen.SurfaceRules$Condition
+public net.minecraft.world.level.levelgen.SurfaceRules$Context
+public net.minecraft.world.level.levelgen.SurfaceRules$Context blockX
+public net.minecraft.world.level.levelgen.SurfaceRules$Context blockY
+public net.minecraft.world.level.levelgen.SurfaceRules$Context blockZ
+public net.minecraft.world.level.levelgen.SurfaceRules$Context context
+public net.minecraft.world.level.levelgen.SurfaceRules$Context randomState
+public net.minecraft.world.level.levelgen.SurfaceRules$LazyYCondition
+public net.minecraft.world.level.levelgen.SurfaceRules$LazyCondition
+public net.minecraft.world.level.levelgen.SurfaceRules$VerticalGradientConditionSource
+public net.minecraft.world.level.levelgen.SurfaceRules$SurfaceRule
+
+Co-authored-by: Noah van der Aa <ndvdaa@gmail.com>
+
+diff --git a/src/main/java/io/papermc/paper/world/worldgen/OptionallyFlatBedrockConditionSource.java b/src/main/java/io/papermc/paper/world/worldgen/OptionallyFlatBedrockConditionSource.java
+new file mode 100644
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000
+--- /dev/null
++++ b/src/main/java/io/papermc/paper/world/worldgen/OptionallyFlatBedrockConditionSource.java
+@@ -0,0 +0,0 @@
++package io.papermc.paper.world.worldgen;
++
++import com.mojang.serialization.Codec;
++import com.mojang.serialization.codecs.RecordCodecBuilder;
++import net.minecraft.core.Registry;
++import net.minecraft.core.registries.BuiltInRegistries;
++import net.minecraft.core.registries.Registries;
++import net.minecraft.resources.ResourceKey;
++import net.minecraft.resources.ResourceLocation;
++import net.minecraft.util.KeyDispatchDataCodec;
++import net.minecraft.util.Mth;
++import net.minecraft.util.RandomSource;
++import net.minecraft.world.level.levelgen.PositionalRandomFactory;
++import net.minecraft.world.level.levelgen.SurfaceRules;
++import net.minecraft.world.level.levelgen.VerticalAnchor;
++import org.checkerframework.checker.nullness.qual.NonNull;
++import org.checkerframework.framework.qual.DefaultQualifier;
++
++// Modelled off of SurfaceRules$VerticalGradientConditionSource
++@DefaultQualifier(NonNull.class)
++public record OptionallyFlatBedrockConditionSource(ResourceLocation randomName, VerticalAnchor trueAtAndBelow, VerticalAnchor falseAtAndAbove, boolean isRoof) implements SurfaceRules.ConditionSource {
++
++    private static final ResourceKey<Codec<? extends SurfaceRules.ConditionSource>> CODEC_RESOURCE_KEY = ResourceKey.create(Registries.MATERIAL_CONDITION, new ResourceLocation(ResourceLocation.PAPER_NAMESPACE, "optionally_flat_bedrock_condition_source"));
++    private static final KeyDispatchDataCodec<OptionallyFlatBedrockConditionSource> CODEC = KeyDispatchDataCodec.of(RecordCodecBuilder.mapCodec((instance) -> {
++        return instance.group(
++            ResourceLocation.CODEC.fieldOf("random_name").forGetter(OptionallyFlatBedrockConditionSource::randomName),
++            VerticalAnchor.CODEC.fieldOf("true_at_and_below").forGetter(OptionallyFlatBedrockConditionSource::trueAtAndBelow),
++            VerticalAnchor.CODEC.fieldOf("false_at_and_above").forGetter(OptionallyFlatBedrockConditionSource::falseAtAndAbove),
++            Codec.BOOL.fieldOf("is_roof").forGetter(OptionallyFlatBedrockConditionSource::isRoof)
++        ).apply(instance, OptionallyFlatBedrockConditionSource::new);
++    }));
++
++    public static void bootstrap() {
++        Registry.register(BuiltInRegistries.MATERIAL_CONDITION, CODEC_RESOURCE_KEY, CODEC.codec());
++    }
++
++    @Override
++    public KeyDispatchDataCodec<? extends SurfaceRules.ConditionSource> codec() {
++        return CODEC;
++    }
++
++    @Override
++    public SurfaceRules.Condition apply(final SurfaceRules.Context context) {
++        boolean hasFlatBedrock = context.context.getWorld().paperConfig().environment.generateFlatBedrock;
++        int tempTrueAtAndBelowY = this.trueAtAndBelow().resolveY(context.context);
++        int tempFalseAtAndAboveY = this.falseAtAndAbove().resolveY(context.context);
++
++        int flatYLevel = this.isRoof ? Math.max(tempFalseAtAndAboveY, tempTrueAtAndBelowY) - 1 : Math.min(tempFalseAtAndAboveY, tempTrueAtAndBelowY);
++        final int trueAtAndBelowY = hasFlatBedrock ? flatYLevel : tempTrueAtAndBelowY;
++        final int falseAtAndAboveY = hasFlatBedrock ? flatYLevel : tempFalseAtAndAboveY;
++
++        final PositionalRandomFactory positionalRandomFactory = context.randomState.getOrCreateRandomFactory(this.randomName());
++
++        class VerticalGradientCondition extends SurfaceRules.LazyYCondition {
++            VerticalGradientCondition(SurfaceRules.Context context) {
++                super(context);
++            }
++
++            @Override
++            protected boolean compute() {
++                int blockY = this.context.blockY;
++                if (blockY <= trueAtAndBelowY) {
++                    return true;
++                } else if (blockY >= falseAtAndAboveY) {
++                    return false;
++                } else {
++                    double d = Mth.map(blockY, trueAtAndBelowY, falseAtAndAboveY, 1.0D, 0.0D);
++                    RandomSource randomSource = positionalRandomFactory.at(this.context.blockX, blockY, this.context.blockZ);
++                    return (double)randomSource.nextFloat() < d;
++                }
++            }
++        }
++
++        return new VerticalGradientCondition(context);
++    }
++}
+diff --git a/src/main/java/net/minecraft/server/Bootstrap.java b/src/main/java/net/minecraft/server/Bootstrap.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/server/Bootstrap.java
++++ b/src/main/java/net/minecraft/server/Bootstrap.java
+@@ -0,0 +0,0 @@ public class Bootstrap {
+                     CauldronInteraction.bootStrap();
+                     // Paper start
+                     BuiltInRegistries.bootStrap(() -> {
++                        io.papermc.paper.world.worldgen.OptionallyFlatBedrockConditionSource.bootstrap(); // Paper - Flat bedrock generator settings
+                         io.papermc.paper.plugin.entrypoint.LaunchEntryPointHandler.enterBootstrappers(); // Paper - Entrypoint for bootstrapping
+                     });
+                     // Paper end
+diff --git a/src/main/java/net/minecraft/world/level/levelgen/NoiseBasedChunkGenerator.java b/src/main/java/net/minecraft/world/level/levelgen/NoiseBasedChunkGenerator.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/world/level/levelgen/NoiseBasedChunkGenerator.java
++++ b/src/main/java/net/minecraft/world/level/levelgen/NoiseBasedChunkGenerator.java
+@@ -0,0 +0,0 @@ public final class NoiseBasedChunkGenerator extends ChunkGenerator {
+     @Override
+     public void buildSurface(WorldGenRegion region, StructureManager structures, RandomState noiseConfig, ChunkAccess chunk) {
+         if (!SharedConstants.debugVoidTerrain(chunk.getPos())) {
+-            WorldGenerationContext worldgenerationcontext = new WorldGenerationContext(this, region);
++            WorldGenerationContext worldgenerationcontext = new WorldGenerationContext(this, region, region.getMinecraftWorld()); // Paper - Flat bedrock generator settings
+ 
+             this.buildSurface(chunk, worldgenerationcontext, noiseConfig, structures, region.getBiomeManager(), region.registryAccess().registryOrThrow(Registries.BIOME), Blender.of(region));
+         }
+@@ -0,0 +0,0 @@ public final class NoiseBasedChunkGenerator extends ChunkGenerator {
+             return this.createNoiseChunk(ichunkaccess1, structureAccessor, Blender.of(chunkRegion), noiseConfig);
+         });
+         Aquifer aquifer = noisechunk.aquifer();
+-        CarvingContext carvingcontext = new CarvingContext(this, chunkRegion.registryAccess(), chunk.getHeightAccessorForGeneration(), noisechunk, noiseConfig, ((NoiseGeneratorSettings) this.settings.value()).surfaceRule());
++        CarvingContext carvingcontext = new CarvingContext(this, chunkRegion.registryAccess(), chunk.getHeightAccessorForGeneration(), noisechunk, noiseConfig, ((NoiseGeneratorSettings) this.settings.value()).surfaceRule(), chunkRegion.getMinecraftWorld()); // Paper - Flat bedrock generator settings
+         CarvingMask carvingmask = ((ProtoChunk) chunk).getOrCreateCarvingMask(carverStep);
+ 
+         for (int j = -8; j <= 8; ++j) {
+diff --git a/src/main/java/net/minecraft/world/level/levelgen/WorldGenerationContext.java b/src/main/java/net/minecraft/world/level/levelgen/WorldGenerationContext.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/world/level/levelgen/WorldGenerationContext.java
++++ b/src/main/java/net/minecraft/world/level/levelgen/WorldGenerationContext.java
+@@ -0,0 +0,0 @@ import net.minecraft.world.level.chunk.ChunkGenerator;
+ public class WorldGenerationContext {
+     private final int minY;
+     private final int height;
++    private final @javax.annotation.Nullable net.minecraft.world.level.Level level; // Paper - Flat bedrock generator settings
+ 
+-    public WorldGenerationContext(ChunkGenerator generator, LevelHeightAccessor world) {
++    public WorldGenerationContext(ChunkGenerator generator, LevelHeightAccessor world) { this(generator, world, null); } // Paper - Flat bedrock generator settings
++    public WorldGenerationContext(ChunkGenerator generator, LevelHeightAccessor world, @org.jetbrains.annotations.Nullable net.minecraft.world.level.Level level) { // Paper - Flat bedrock generator settings
+         this.minY = Math.max(world.getMinBuildHeight(), generator.getMinY());
+         this.height = Math.min(world.getHeight(), generator.getGenDepth());
++        this.level = level; // Paper - Flat bedrock generator settings
+     }
+ 
+     public int getMinGenY() {
+@@ -0,0 +0,0 @@ public class WorldGenerationContext {
+     public int getGenDepth() {
+         return this.height;
+     }
++
++    // Paper start - Flat bedrock generator settings
++    public net.minecraft.world.level.Level getWorld() {
++        if (this.level == null) {
++            throw new NullPointerException("WorldGenerationContext was initialized without a Level, but WorldGenerationContext#getWorld was called");
++        }
++        return this.level;
++    }
++    // Paper end - Flat bedrock generator settings
+ }
+diff --git a/src/main/java/net/minecraft/world/level/levelgen/carver/CarvingContext.java b/src/main/java/net/minecraft/world/level/levelgen/carver/CarvingContext.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/world/level/levelgen/carver/CarvingContext.java
++++ b/src/main/java/net/minecraft/world/level/levelgen/carver/CarvingContext.java
+@@ -0,0 +0,0 @@ public class CarvingContext extends WorldGenerationContext {
+         LevelHeightAccessor heightLimitView,
+         NoiseChunk chunkNoiseSampler,
+         RandomState noiseConfig,
+-        SurfaceRules.RuleSource materialRule
++        SurfaceRules.RuleSource materialRule, @javax.annotation.Nullable net.minecraft.world.level.Level level  // Paper - Flat bedrock generator settings
+     ) {
+-        super(noiseChunkGenerator, heightLimitView);
++        super(noiseChunkGenerator, heightLimitView, level); // Paper - Flat bedrock generator settings
+         this.registryAccess = registryManager;
+         this.noiseChunk = chunkNoiseSampler;
+         this.randomState = noiseConfig;
+diff --git a/src/main/java/net/minecraft/world/level/levelgen/placement/PlacementContext.java b/src/main/java/net/minecraft/world/level/levelgen/placement/PlacementContext.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/world/level/levelgen/placement/PlacementContext.java
++++ b/src/main/java/net/minecraft/world/level/levelgen/placement/PlacementContext.java
+@@ -0,0 +0,0 @@ public class PlacementContext extends WorldGenerationContext {
+     private final Optional<PlacedFeature> topFeature;
+ 
+     public PlacementContext(WorldGenLevel world, ChunkGenerator generator, Optional<PlacedFeature> placedFeature) {
+-        super(generator, world);
++        super(generator, world, world.getLevel()); // Paper - Flat bedrock generator settings
+         this.level = world;
+         this.generator = generator;
+         this.topFeature = placedFeature;
+diff --git a/src/main/resources/data/minecraft/worldgen/noise_settings/amplified.json b/src/main/resources/data/minecraft/worldgen/noise_settings/amplified.json
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/resources/data/minecraft/worldgen/noise_settings/amplified.json
++++ b/src/main/resources/data/minecraft/worldgen/noise_settings/amplified.json
+@@ -0,0 +0,0 @@
+       {
+         "type": "minecraft:condition",
+         "if_true": {
+-          "type": "minecraft:vertical_gradient",
++          "type": "paper:optionally_flat_bedrock_condition_source",
++          "is_roof": false,
+           "false_at_and_above": {
+             "above_bottom": 5
+           },
+diff --git a/src/main/resources/data/minecraft/worldgen/noise_settings/caves.json b/src/main/resources/data/minecraft/worldgen/noise_settings/caves.json
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/resources/data/minecraft/worldgen/noise_settings/caves.json
++++ b/src/main/resources/data/minecraft/worldgen/noise_settings/caves.json
+@@ -0,0 +0,0 @@
+         "if_true": {
+           "type": "minecraft:not",
+           "invert": {
+-            "type": "minecraft:vertical_gradient",
++            "type": "paper:optionally_flat_bedrock_condition_source",
++            "is_roof": true,
+             "false_at_and_above": {
+               "below_top": 0
+             },
+@@ -0,0 +0,0 @@
+       {
+         "type": "minecraft:condition",
+         "if_true": {
+-          "type": "minecraft:vertical_gradient",
++          "type": "paper:optionally_flat_bedrock_condition_source",
++          "is_roof": false,
+           "false_at_and_above": {
+             "above_bottom": 5
+           },
+diff --git a/src/main/resources/data/minecraft/worldgen/noise_settings/large_biomes.json b/src/main/resources/data/minecraft/worldgen/noise_settings/large_biomes.json
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/resources/data/minecraft/worldgen/noise_settings/large_biomes.json
++++ b/src/main/resources/data/minecraft/worldgen/noise_settings/large_biomes.json
+@@ -0,0 +0,0 @@
+       {
+         "type": "minecraft:condition",
+         "if_true": {
+-          "type": "minecraft:vertical_gradient",
++          "type": "paper:optionally_flat_bedrock_condition_source",
++          "is_roof": false,
+           "false_at_and_above": {
+             "above_bottom": 5
+           },
+diff --git a/src/main/resources/data/minecraft/worldgen/noise_settings/nether.json b/src/main/resources/data/minecraft/worldgen/noise_settings/nether.json
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/resources/data/minecraft/worldgen/noise_settings/nether.json
++++ b/src/main/resources/data/minecraft/worldgen/noise_settings/nether.json
+@@ -0,0 +0,0 @@
+       {
+         "type": "minecraft:condition",
+         "if_true": {
+-          "type": "minecraft:vertical_gradient",
++          "type": "paper:optionally_flat_bedrock_condition_source",
++          "is_roof": false,
+           "false_at_and_above": {
+             "above_bottom": 5
+           },
+@@ -0,0 +0,0 @@
+         "if_true": {
+           "type": "minecraft:not",
+           "invert": {
+-            "type": "minecraft:vertical_gradient",
++            "type": "paper:optionally_flat_bedrock_condition_source",
++            "is_roof": true,
+             "false_at_and_above": {
+               "below_top": 0
+             },
+diff --git a/src/main/resources/data/minecraft/worldgen/noise_settings/overworld.json b/src/main/resources/data/minecraft/worldgen/noise_settings/overworld.json
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/resources/data/minecraft/worldgen/noise_settings/overworld.json
++++ b/src/main/resources/data/minecraft/worldgen/noise_settings/overworld.json
+@@ -0,0 +0,0 @@
+       {
+         "type": "minecraft:condition",
+         "if_true": {
+-          "type": "minecraft:vertical_gradient",
++          "type": "paper:optionally_flat_bedrock_condition_source",
++          "is_roof": false,
+           "false_at_and_above": {
+             "above_bottom": 5
+           },

patches/server/Improve-Maps-in-item-frames-performance-and-bug-fixe.patch

@@ -0,0 +1,128 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Aikar <aikar@aikar.co>
+Date: Fri, 29 Apr 2016 20:02:00 -0400
+Subject: [PATCH] Improve Maps (in item frames) performance and bug fixes
+
+Maps used a modified version of rendering to support plugin controlled
+imaging on maps. The Craft Map Renderer is much slower than Vanilla,
+causing maps in item frames to cause a noticeable hit on server performance.
+
+This updates the map system to not use the Craft system if we detect that no
+custom renderers are in use, defaulting to the much simpler Vanilla system.
+
+Additionally, numerous issues to player position tracking on maps has been fixed.
+
+diff --git a/src/main/java/net/minecraft/server/level/ServerLevel.java b/src/main/java/net/minecraft/server/level/ServerLevel.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/server/level/ServerLevel.java
++++ b/src/main/java/net/minecraft/server/level/ServerLevel.java
+@@ -0,0 +0,0 @@ public class ServerLevel extends Level implements WorldGenLevel {
+                             {
+                                 if ( iter.next().player == entity )
+                                 {
++                                    map.decorations.remove(entity.getName().getString()); // Paper
+                                     iter.remove();
+                                 }
+                             }
+diff --git a/src/main/java/net/minecraft/world/entity/player/Player.java b/src/main/java/net/minecraft/world/entity/player/Player.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/world/entity/player/Player.java
++++ b/src/main/java/net/minecraft/world/entity/player/Player.java
+@@ -0,0 +0,0 @@ public abstract class Player extends LivingEntity {
+                 return null;
+             }
+             // CraftBukkit end
++            // Paper start - remove player from map on drop
++            if (itemstack.getItem() == Items.FILLED_MAP) {
++                net.minecraft.world.level.saveddata.maps.MapItemSavedData worldmap = net.minecraft.world.item.MapItem.getSavedData(itemstack, this.level());
++                if (worldmap != null) {
++                    worldmap.tickCarriedBy(this, itemstack);
++                }
++            }
++            // Paper end
+ 
+             return entityitem;
+         }
+diff --git a/src/main/java/net/minecraft/world/level/saveddata/maps/MapItemSavedData.java b/src/main/java/net/minecraft/world/level/saveddata/maps/MapItemSavedData.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/world/level/saveddata/maps/MapItemSavedData.java
++++ b/src/main/java/net/minecraft/world/level/saveddata/maps/MapItemSavedData.java
+@@ -0,0 +0,0 @@ public class MapItemSavedData extends SavedData {
+     public final Map<String, MapDecoration> decorations = Maps.newLinkedHashMap();
+     private final Map<String, MapFrame> frameMarkers = Maps.newHashMap();
+     private int trackedDecorationCount;
++    private org.bukkit.craftbukkit.map.RenderData vanillaRender = new org.bukkit.craftbukkit.map.RenderData(); // Paper
+ 
+     // CraftBukkit start
+     public final CraftMapView mapView;
+@@ -0,0 +0,0 @@ public class MapItemSavedData extends SavedData {
+         // CraftBukkit start
+         this.mapView = new CraftMapView(this);
+         this.server = (CraftServer) org.bukkit.Bukkit.getServer();
++        this.vanillaRender.buffer = colors; // Paper
+         // CraftBukkit end
+     }
+ 
+@@ -0,0 +0,0 @@ public class MapItemSavedData extends SavedData {
+         if (abyte.length == 16384) {
+             worldmap.colors = abyte;
+         }
++        worldmap.vanillaRender.buffer = abyte; // Paper
+ 
+         RegistryOps<Tag> registryops = registryLookup.createSerializationContext(NbtOps.INSTANCE);
+         List<MapBanner> list = (List) MapBanner.LIST_CODEC.parse(registryops, nbt.get("banners")).resultOrPartial((s) -> {
+@@ -0,0 +0,0 @@ public class MapItemSavedData extends SavedData {
+ 
+     public class HoldingPlayer {
+ 
++        // Paper start
++        private void addSeenPlayers(java.util.Collection<MapDecoration> icons) {
++            org.bukkit.entity.Player player = (org.bukkit.entity.Player) this.player.getBukkitEntity();
++            MapItemSavedData.this.decorations.forEach((name, mapIcon) -> {
++                // If this cursor is for a player check visibility with vanish system
++                org.bukkit.entity.Player other = org.bukkit.Bukkit.getPlayerExact(name); // Spigot
++                if (other == null || player.canSee(other)) {
++                    icons.add(mapIcon);
++                }
++            });
++        }
++        private boolean shouldUseVanillaMap() {
++            return mapView.getRenderers().size() == 1 && mapView.getRenderers().get(0).getClass() == org.bukkit.craftbukkit.map.CraftMapRenderer.class;
++        }
++        // Paper end
+         public final Player player;
+         private boolean dirtyData = true;
+         private int minDirtyX;
+@@ -0,0 +0,0 @@ public class MapItemSavedData extends SavedData {
+         @Nullable
+         Packet<?> nextUpdatePacket(MapId mapId) {
+             MapItemSavedData.MapPatch worldmap_b;
+-            org.bukkit.craftbukkit.map.RenderData render = MapItemSavedData.this.mapView.render((org.bukkit.craftbukkit.entity.CraftPlayer) this.player.getBukkitEntity()); // CraftBukkit
++            if (!this.dirtyData && this.tick % 5 != 0) { this.tick++; return null; } // Paper - this won't end up sending, so don't render it!
++            boolean vanillaMaps = shouldUseVanillaMap(); // Paper
++            org.bukkit.craftbukkit.map.RenderData render = !vanillaMaps ? MapItemSavedData.this.mapView.render((org.bukkit.craftbukkit.entity.CraftPlayer) this.player.getBukkitEntity()) : MapItemSavedData.this.vanillaRender; // CraftBukkit // Paper
+ 
+             if (this.dirtyData) {
+                 this.dirtyData = false;
+@@ -0,0 +0,0 @@ public class MapItemSavedData extends SavedData {
+                 // CraftBukkit start
+                 java.util.Collection<MapDecoration> icons = new java.util.ArrayList<MapDecoration>();
+ 
++                if (vanillaMaps) addSeenPlayers(icons); // Paper
++
+                 for (org.bukkit.map.MapCursor cursor : render.cursors) {
+                     if (cursor.isVisible()) {
+                         icons.add(new MapDecoration(CraftMapCursor.CraftType.bukkitToMinecraftHolder(cursor.getType()), cursor.getX(), cursor.getY(), cursor.getDirection(), Optional.ofNullable(PaperAdventure.asVanilla(cursor.caption()))));
+diff --git a/src/main/java/org/bukkit/craftbukkit/map/RenderData.java b/src/main/java/org/bukkit/craftbukkit/map/RenderData.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/org/bukkit/craftbukkit/map/RenderData.java
++++ b/src/main/java/org/bukkit/craftbukkit/map/RenderData.java
+@@ -0,0 +0,0 @@ import org.bukkit.map.MapCursor;
+ 
+ public class RenderData {
+ 
+-    public final byte[] buffer;
++    public byte[] buffer; // Paper
+     public final ArrayList<MapCursor> cursors;
+ 
+     public RenderData() {

patches/server/Improve-cancelling-PreCreatureSpawnEvent-with-per-pl.patch

@@ -0,0 +1,89 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: kickash32 <kickash32@gmail.com>
+Date: Mon, 5 Apr 2021 01:42:35 -0400
+Subject: [PATCH] Improve cancelling PreCreatureSpawnEvent with per player mob
+ spawns
+
+
+diff --git a/src/main/java/net/minecraft/server/level/ChunkMap.java b/src/main/java/net/minecraft/server/level/ChunkMap.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/server/level/ChunkMap.java
++++ b/src/main/java/net/minecraft/server/level/ChunkMap.java
+@@ -0,0 +0,0 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
+         }
+     }
+ 
++    // Paper start - per player mob count backoff
++    public void updateFailurePlayerMobTypeMap(int chunkX, int chunkZ, net.minecraft.world.entity.MobCategory mobCategory) {
++        if (!this.level.paperConfig().entities.spawning.perPlayerMobSpawns) {
++            return;
++        }
++        int idx = mobCategory.ordinal();
++        final com.destroystokyo.paper.util.maplist.ReferenceList<ServerPlayer> inRange =
++            this.getNearbyPlayers().getPlayersByChunk(chunkX, chunkZ, io.papermc.paper.util.player.NearbyPlayers.NearbyMapType.TICK_VIEW_DISTANCE);
++        if (inRange == null) {
++            return;
++        }
++        final Object[] backingSet = inRange.getRawData();
++        for (int i = 0, len = inRange.size(); i < len; i++) {
++            ++((ServerPlayer)backingSet[i]).mobBackoffCounts[idx];
++        }
++    }
++    // Paper end - per player mob count backoff
+     public int getMobCountNear(final ServerPlayer player, final net.minecraft.world.entity.MobCategory mobCategory) {
+-        return player.mobCounts[mobCategory.ordinal()];
++        return player.mobCounts[mobCategory.ordinal()] + player.mobBackoffCounts[mobCategory.ordinal()]; // Paper - per player mob count backoff
+     }
+     // Paper end - Optional per player mob spawns
+ 
+diff --git a/src/main/java/net/minecraft/server/level/ServerChunkCache.java b/src/main/java/net/minecraft/server/level/ServerChunkCache.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/server/level/ServerChunkCache.java
++++ b/src/main/java/net/minecraft/server/level/ServerChunkCache.java
+@@ -0,0 +0,0 @@ public class ServerChunkCache extends ChunkSource {
+                 if ((this.spawnFriendlies || this.spawnEnemies) && this.level.paperConfig().entities.spawning.perPlayerMobSpawns) { // don't count mobs when animals and monsters are disabled
+                     // re-set mob counts
+                     for (ServerPlayer player : this.level.players) {
+-                        Arrays.fill(player.mobCounts, 0);
++                        // Paper start - per player mob spawning backoff
++                        for (int ii = 0; ii < ServerPlayer.MOBCATEGORY_TOTAL_ENUMS; ii++) {
++                            player.mobCounts[ii] = 0;
++
++                            int newBackoff = player.mobBackoffCounts[ii] - 1; // TODO make configurable bleed // TODO use nonlinear algorithm?
++                            if (newBackoff < 0) {
++                                newBackoff = 0;
++                            }
++                            player.mobBackoffCounts[ii] = newBackoff;
++                        }
++                        // Paper end - per player mob spawning backoff
+                     }
+                     spawnercreature_d = NaturalSpawner.createState(naturalSpawnChunkCount, this.level.getAllEntities(), this::getFullChunk, null, true);
+                 } else {
+diff --git a/src/main/java/net/minecraft/server/level/ServerPlayer.java b/src/main/java/net/minecraft/server/level/ServerPlayer.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/server/level/ServerPlayer.java
++++ b/src/main/java/net/minecraft/server/level/ServerPlayer.java
+@@ -0,0 +0,0 @@ public class ServerPlayer extends Player {
+     public static final int MOBCATEGORY_TOTAL_ENUMS = net.minecraft.world.entity.MobCategory.values().length;
+     public final int[] mobCounts = new int[MOBCATEGORY_TOTAL_ENUMS]; // Paper
+     // Paper end - Optional per player mob spawns
++    public final int[] mobBackoffCounts = new int[MOBCATEGORY_TOTAL_ENUMS]; // Paper - per player mob count backoff
+ 
+     // CraftBukkit start
+     public CraftPlayer.TransferCookieConnection transferCookieConnection;
+diff --git a/src/main/java/net/minecraft/world/level/NaturalSpawner.java b/src/main/java/net/minecraft/world/level/NaturalSpawner.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/world/level/NaturalSpawner.java
++++ b/src/main/java/net/minecraft/world/level/NaturalSpawner.java
+@@ -0,0 +0,0 @@ public final class NaturalSpawner {
+ 
+                                     // Paper start - PreCreatureSpawnEvent
+                                     PreSpawnStatus doSpawning = isValidSpawnPostitionForType(world, group, structuremanager, chunkgenerator, biomesettingsmobs_c, blockposition_mutableblockposition, d2);
++                                    // Paper start - per player mob count backoff
++                                    if (doSpawning == PreSpawnStatus.ABORT || doSpawning == PreSpawnStatus.CANCELLED) {
++                                        world.getChunkSource().chunkMap.updateFailurePlayerMobTypeMap(blockposition_mutableblockposition.getX() >> 4, blockposition_mutableblockposition.getZ() >> 4, group);
++                                    }
++                                    // Paper end - per player mob count backoff
+                                     if (doSpawning == PreSpawnStatus.ABORT) {
+                                         return j; // Paper - Optional per player mob spawns
+                                     }

patches/server/Optimize-Collision-to-not-load-chunks.patch

@@ -0,0 +1,109 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Aikar <aikar@aikar.co>
+Date: Thu, 2 Apr 2020 02:37:57 -0400
+Subject: [PATCH] Optimize Collision to not load chunks
+
+The collision code takes an AABB and generates a cuboid of checks rather
+than a cylinder, so at high velocity this can generate a lot of chunk checks.
+
+Treat an unloaded chunk as a collision for entities, and also for players if
+the "prevent moving into unloaded chunks" setting is enabled.
+
+If that serting is not enabled, collisions will be ignored for players, since
+movement will load only the chunk the player enters anyways and avoids loading
+massive amounts of surrounding chunks due to large AABB lookups.
+
+diff --git a/src/main/java/net/minecraft/server/players/PlayerList.java b/src/main/java/net/minecraft/server/players/PlayerList.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/server/players/PlayerList.java
++++ b/src/main/java/net/minecraft/server/players/PlayerList.java
+@@ -0,0 +0,0 @@ public abstract class PlayerList {
+         entityplayer1.setShiftKeyDown(false);
+         entityplayer1.forceSetPositionRotation(location.getX(), location.getY(), location.getZ(), location.getYaw(), location.getPitch());
+ 
++        worldserver1.getChunkSource().addRegionTicket(net.minecraft.server.level.TicketType.POST_TELEPORT, new net.minecraft.world.level.ChunkPos(location.getBlockX() >> 4, location.getBlockZ() >> 4), 1, entityplayer.getId()); // Paper
+         while (avoidSuffocation && !worldserver1.noCollision((Entity) entityplayer1) && entityplayer1.getY() < (double) worldserver1.getMaxBuildHeight()) {
+             // CraftBukkit end
+             entityplayer1.setPos(entityplayer1.getX(), entityplayer1.getY() + 1.0D, entityplayer1.getZ());
+diff --git a/src/main/java/net/minecraft/world/entity/Entity.java b/src/main/java/net/minecraft/world/entity/Entity.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/world/entity/Entity.java
++++ b/src/main/java/net/minecraft/world/entity/Entity.java
+@@ -0,0 +0,0 @@ public abstract class Entity implements SyncedDataHolder, Nameable, EntityAccess
+     public org.bukkit.event.entity.CreatureSpawnEvent.SpawnReason spawnReason; // Paper - Entity#getEntitySpawnReason
+ 
+     public com.destroystokyo.paper.loottable.PaperLootableInventoryData lootableData; // Paper
++    public boolean collisionLoadChunks = false; // Paper
+     private CraftEntity bukkitEntity;
+ 
+     public @org.jetbrains.annotations.Nullable net.minecraft.server.level.ChunkMap.TrackedEntity tracker; // Paper
+diff --git a/src/main/java/net/minecraft/world/level/BlockCollisions.java b/src/main/java/net/minecraft/world/level/BlockCollisions.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/world/level/BlockCollisions.java
++++ b/src/main/java/net/minecraft/world/level/BlockCollisions.java
+@@ -0,0 +0,0 @@ public class BlockCollisions<T> extends AbstractIterator<T> {
+     @Override
+     protected T computeNext() {
+         while (this.cursor.advance()) {
+-            int i = this.cursor.nextX();
+-            int j = this.cursor.nextY();
+-            int k = this.cursor.nextZ();
++            int i = this.cursor.nextX(); final int x = i; // Paper - OBFHELPER
++            int j = this.cursor.nextY(); final int y = j; // Paper - OBFHELPER
++            int k = this.cursor.nextZ(); final int z = k; // Paper - OBFHELPER
+             int l = this.cursor.getNextType();
+             if (l != 3) {
+-                BlockGetter blockGetter = this.getChunk(i, k);
+-                if (blockGetter != null) {
+-                    this.pos.set(i, j, k);
+-                    BlockState blockState = blockGetter.getBlockState(this.pos);
+-                    if ((!this.onlySuffocatingBlocks || blockState.isSuffocating(blockGetter, this.pos))
+-                        && (l != 1 || blockState.hasLargeCollisionShape())
+-                        && (l != 2 || blockState.is(Blocks.MOVING_PISTON))) {
++                // Paper start - ensure we don't load chunks
++                // BlockGetter blockGetter = this.getChunk(i, k);
++                if (true) {
++                    final @Nullable Entity source = this.context instanceof net.minecraft.world.phys.shapes.EntityCollisionContext entityContext ? entityContext.getEntity() : null;
++                    boolean far = source != null && io.papermc.paper.util.MCUtil.distanceSq(source.getX(), y, source.getZ(), x, y, z) > 14;
++                    this.pos.set(x, y, z);
++                    BlockState blockState;
++                    if (this.collisionGetter instanceof net.minecraft.server.level.WorldGenRegion) {
++                        BlockGetter blockGetter = this.getChunk(x, z);
++                        if (blockGetter == null) {
++                           continue;
++                        }
++                        blockState = blockGetter.getBlockState(this.pos);
++                    } else if ((!far && source instanceof net.minecraft.server.level.ServerPlayer) || (source != null && source.collisionLoadChunks)) {
++                        blockState = this.collisionGetter.getBlockState(this.pos);
++                    } else {
++                        blockState = this.collisionGetter.getBlockStateIfLoaded(this.pos);
++                    }
++                    if (blockState == null) {
++                        if (!(source instanceof net.minecraft.server.level.ServerPlayer) || source.level().paperConfig().chunks.preventMovingIntoUnloadedChunks) {
++                            return this.resultProvider.apply(new BlockPos.MutableBlockPos(x, y, z), Shapes.create(far ? source.getBoundingBox() : new AABB(new BlockPos(x, y, z))));
++                        }
++                        continue;
++                    }
++                    if (/*(!this.onlySuffocatingBlocks || blockState.isSuffocating(blockGetter, this.pos)) &&*/ (l != 1 || blockState.hasLargeCollisionShape()) && (l != 2 || blockState.is(Blocks.MOVING_PISTON))) { // Paper - onlySuffocatingBlocks is only true on the client, so we don't care about it here
++                        // Paper end
+                         VoxelShape voxelShape = blockState.getCollisionShape(this.collisionGetter, this.pos, this.context);
+                         if (voxelShape == Shapes.block()) {
+                             if (this.box.intersects((double)i, (double)j, (double)k, (double)i + 1.0, (double)j + 1.0, (double)k + 1.0)) {
+diff --git a/src/main/java/net/minecraft/world/level/CollisionGetter.java b/src/main/java/net/minecraft/world/level/CollisionGetter.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/world/level/CollisionGetter.java
++++ b/src/main/java/net/minecraft/world/level/CollisionGetter.java
+@@ -0,0 +0,0 @@ public interface CollisionGetter extends BlockGetter {
+     }
+ 
+     default boolean noCollision(@Nullable Entity entity, AABB box) {
++        try { if (entity != null) entity.collisionLoadChunks = true; // Paper
+         for (VoxelShape voxelShape : this.getBlockCollisions(entity, box)) {
+             if (!voxelShape.isEmpty()) {
+                 return false;
+             }
+         }
++        } finally { if (entity != null) entity.collisionLoadChunks = false; } // Paper
+ 
+         if (!this.getEntityCollisions(entity, box).isEmpty()) {
+             return false;

patches/server/Optimize-GoalSelector-Goal.Flag-Set-operations.patch

@@ -0,0 +1,160 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Spottedleaf <Spottedleaf@users.noreply.github.com>
+Date: Mon, 6 Apr 2020 17:53:29 -0700
+Subject: [PATCH] Optimize GoalSelector Goal.Flag Set operations
+
+Optimise the stream.anyMatch statement to move to a bitset
+where we can replace the call with a single bitwise operation.
+
+diff --git a/src/main/java/net/minecraft/world/entity/ai/goal/Goal.java b/src/main/java/net/minecraft/world/entity/ai/goal/Goal.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/world/entity/ai/goal/Goal.java
++++ b/src/main/java/net/minecraft/world/entity/ai/goal/Goal.java
+@@ -0,0 +0,0 @@ import java.util.EnumSet;
+ import net.minecraft.util.Mth;
+ 
+ public abstract class Goal {
+-    private final EnumSet<Goal.Flag> flags = EnumSet.noneOf(Goal.Flag.class);
++    private final EnumSet<Goal.Flag> flags = EnumSet.noneOf(Goal.Flag.class); // Paper unused, but dummy to prevent plugins from crashing as hard. Theyll need to support paper in a special case if this is super important, but really doesn't seem like it would be.
++    private final com.destroystokyo.paper.util.set.OptimizedSmallEnumSet<net.minecraft.world.entity.ai.goal.Goal.Flag> goalTypes = new com.destroystokyo.paper.util.set.OptimizedSmallEnumSet<>(Goal.Flag.class); // Paper - remove streams from pathfindergoalselector
++
++    // Paper start - remove streams from pathfindergoalselector; make sure types are not empty
++    public Goal() {
++        if (this.goalTypes.size() == 0) {
++            this.goalTypes.add(Flag.UNKNOWN_BEHAVIOR);
++        }
++    }
++    // Paper end - remove streams from pathfindergoalselector
+ 
+     public abstract boolean canUse();
+ 
+@@ -0,0 +0,0 @@ public abstract class Goal {
+     }
+ 
+     public void setFlags(EnumSet<Goal.Flag> controls) {
+-        this.flags.clear();
+-        this.flags.addAll(controls);
++        // Paper start - remove streams from pathfindergoalselector
++        this.goalTypes.clear();
++        this.goalTypes.addAll(controls);
++        if (this.goalTypes.size() == 0) {
++            this.goalTypes.add(Flag.UNKNOWN_BEHAVIOR);
++        }
++        // Paper end - remove streams from pathfindergoalselector
+     }
+ 
+     @Override
+@@ -0,0 +0,0 @@ public abstract class Goal {
+         return this.getClass().getSimpleName();
+     }
+ 
+-    public EnumSet<Goal.Flag> getFlags() {
+-        return this.flags;
++    // Paper start - remove streams from pathfindergoalselector
++    public com.destroystokyo.paper.util.set.OptimizedSmallEnumSet<Goal.Flag> getFlags() {
++        return this.goalTypes;
++        // Paper end - remove streams from pathfindergoalselector
+     }
+ 
+     protected int adjustedTickDelay(int ticks) {
+diff --git a/src/main/java/net/minecraft/world/entity/ai/goal/GoalSelector.java b/src/main/java/net/minecraft/world/entity/ai/goal/GoalSelector.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/world/entity/ai/goal/GoalSelector.java
++++ b/src/main/java/net/minecraft/world/entity/ai/goal/GoalSelector.java
+@@ -0,0 +0,0 @@ public class GoalSelector {
+     private final Map<Goal.Flag, WrappedGoal> lockedFlags = new EnumMap<>(Goal.Flag.class);
+     private final Set<WrappedGoal> availableGoals = new ObjectLinkedOpenHashSet<>();
+     private final Supplier<ProfilerFiller> profiler;
+-    private final EnumSet<Goal.Flag> disabledFlags = EnumSet.noneOf(Goal.Flag.class);
++    private static final Goal.Flag[] GOAL_FLAG_VALUES = Goal.Flag.values(); // Paper - remove streams from pathfindergoalselector
++    private final com.destroystokyo.paper.util.set.OptimizedSmallEnumSet<net.minecraft.world.entity.ai.goal.Goal.Flag> goalTypes = new com.destroystokyo.paper.util.set.OptimizedSmallEnumSet<>(Goal.Flag.class); // Paper - remove streams from pathfindergoalselector
+     private int curRate;
+ 
+     public GoalSelector(Supplier<ProfilerFiller> profiler) {
+@@ -0,0 +0,0 @@ public class GoalSelector {
+         this.availableGoals.removeIf(wrappedGoalx -> wrappedGoalx.getGoal() == goal);
+     }
+ 
+-    private static boolean goalContainsAnyFlags(WrappedGoal goal, EnumSet<Goal.Flag> controls) {
+-        for (Goal.Flag flag : goal.getFlags()) {
+-            if (controls.contains(flag)) {
+-                return true;
+-            }
+-        }
+-
+-        return false;
++    // Paper start
++    private static boolean goalContainsAnyFlags(WrappedGoal goal, com.destroystokyo.paper.util.set.OptimizedSmallEnumSet<Goal.Flag> controls) {
++        return goal.getFlags().hasCommonElements(controls);
+     }
+ 
+     private static boolean goalCanBeReplacedForAllFlags(WrappedGoal goal, Map<Goal.Flag, WrappedGoal> goalsByControl) {
+-        for (Goal.Flag flag : goal.getFlags()) {
++        long flagIterator = goal.getFlags().getBackingSet();
++        int wrappedGoalSize = goal.getFlags().size();
++        for (int i = 0; i < wrappedGoalSize; ++i) {
++            final Goal.Flag flag = GOAL_FLAG_VALUES[Long.numberOfTrailingZeros(flagIterator)];
++            flagIterator ^= io.papermc.paper.util.IntegerUtil.getTrailingBit(flagIterator);
++            // Paper end
+             if (!goalsByControl.getOrDefault(flag, NO_GOAL).canBeReplacedBy(goal)) {
+                 return false;
+             }
+@@ -0,0 +0,0 @@ public class GoalSelector {
+         profilerFiller.push("goalCleanup");
+ 
+         for (WrappedGoal wrappedGoal : this.availableGoals) {
+-            if (wrappedGoal.isRunning() && (goalContainsAnyFlags(wrappedGoal, this.disabledFlags) || !wrappedGoal.canContinueToUse())) {
++            if (wrappedGoal.isRunning() && (goalContainsAnyFlags(wrappedGoal, this.goalTypes) || !wrappedGoal.canContinueToUse())) { // Paper - Perf: optimize goal types by removing streams
+                 wrappedGoal.stop();
+             }
+         }
+@@ -0,0 +0,0 @@ public class GoalSelector {
+         profilerFiller.push("goalUpdate");
+ 
+         for (WrappedGoal wrappedGoal2 : this.availableGoals) {
+-            if (!wrappedGoal2.isRunning()
+-                && !goalContainsAnyFlags(wrappedGoal2, this.disabledFlags)
+-                && goalCanBeReplacedForAllFlags(wrappedGoal2, this.lockedFlags)
+-                && wrappedGoal2.canUse()) {
+-                for (Goal.Flag flag : wrappedGoal2.getFlags()) {
++            // Paper start
++            if (!wrappedGoal2.isRunning() && !goalContainsAnyFlags(wrappedGoal2, this.goalTypes) && goalCanBeReplacedForAllFlags(wrappedGoal2, this.lockedFlags) && wrappedGoal2.canUse()) {
++                long flagIterator = wrappedGoal2.getFlags().getBackingSet();
++                int wrappedGoalSize = wrappedGoal2.getFlags().size();
++                for (int i = 0; i < wrappedGoalSize; ++i) {
++                    final Goal.Flag flag = GOAL_FLAG_VALUES[Long.numberOfTrailingZeros(flagIterator)];
++                    flagIterator ^= io.papermc.paper.util.IntegerUtil.getTrailingBit(flagIterator);
++                    // Paper end
+                     WrappedGoal wrappedGoal3 = this.lockedFlags.getOrDefault(flag, NO_GOAL);
+                     wrappedGoal3.stop();
+                     this.lockedFlags.put(flag, wrappedGoal2);
+@@ -0,0 +0,0 @@ public class GoalSelector {
+     }
+ 
+     public void disableControlFlag(Goal.Flag control) {
+-        this.disabledFlags.add(control);
++        this.goalTypes.add(control); // Paper - remove streams from pathfindergoalselector
+     }
+ 
+     public void enableControlFlag(Goal.Flag control) {
+-        this.disabledFlags.remove(control);
++        this.goalTypes.remove(control); // Paper - remove streams from pathfindergoalselector
+     }
+ 
+     public void setControlFlag(Goal.Flag control, boolean enabled) {
+diff --git a/src/main/java/net/minecraft/world/entity/ai/goal/WrappedGoal.java b/src/main/java/net/minecraft/world/entity/ai/goal/WrappedGoal.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/world/entity/ai/goal/WrappedGoal.java
++++ b/src/main/java/net/minecraft/world/entity/ai/goal/WrappedGoal.java
+@@ -0,0 +0,0 @@ public class WrappedGoal extends Goal {
+     }
+ 
+     @Override
+-    public EnumSet<Goal.Flag> getFlags() {
++    // Paper start - remove streams from pathfindergoalselector
++    public com.destroystokyo.paper.util.set.OptimizedSmallEnumSet<Goal.Flag> getFlags() {
+         return this.goal.getFlags();
++        // Paper end - remove streams from pathfindergoalselector
+     }
+ 
+     public boolean isRunning() {

patches/server/Optimize-Network-Manager-and-add-advanced-packet-sup.patch

@@ -0,0 +1,395 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Aikar <aikar@aikar.co>
+Date: Wed, 6 May 2020 04:53:35 -0400
+Subject: [PATCH] Optimize Network Manager and add advanced packet support
+
+Adds ability for 1 packet to bundle other packets to follow it
+Adds ability for a packet to delay sending more packets until a state is ready.
+
+Removes synchronization from sending packets
+Removes processing packet queue off of main thread
+  - for the few cases where it is allowed, order is not necessary nor
+    should it even be happening concurrently in first place (handshaking/login/status)
+
+Ensures packets sent asynchronously are dispatched on main thread
+
+This helps ensure safety for ProtocolLib as packet listeners
+are commonly accessing world state. This will allow you to schedule
+a packet to be sent async, but itll be dispatched sync for packet
+listeners to process.
+
+This should solve some deadlock risks
+
+Also adds Netty Channel Flush Consolidation to reduce the amount of flushing
+
+Also avoids spamming closed channel exception by rechecking closed state in dispatch
+and then catch exceptions and close if they fire.
+
+Part of this commit was authored by: Spottedleaf, sandtechnology
+
+diff --git a/src/main/java/net/minecraft/network/Connection.java b/src/main/java/net/minecraft/network/Connection.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/network/Connection.java
++++ b/src/main/java/net/minecraft/network/Connection.java
+@@ -0,0 +0,0 @@ public class Connection extends SimpleChannelInboundHandler<Packet<?>> {
+     private static final ProtocolInfo<ServerHandshakePacketListener> INITIAL_PROTOCOL = HandshakeProtocols.SERVERBOUND;
+     private final PacketFlow receiving;
+     private volatile boolean sendLoginDisconnect = true;
+-    private final Queue<Consumer<Connection>> pendingActions = Queues.newConcurrentLinkedQueue();
++    private final Queue<WrappedConsumer> pendingActions = Queues.newConcurrentLinkedQueue(); // Paper
+     public Channel channel;
+     public SocketAddress address;
+     // Spigot Start
+@@ -0,0 +0,0 @@ public class Connection extends SimpleChannelInboundHandler<Packet<?>> {
+     public java.net.InetSocketAddress virtualHost;
+     private static boolean enableExplicitFlush = Boolean.getBoolean("paper.explicit-flush"); // Paper - Disable explicit network manager flushing
+     // Paper end
++    // Paper start - Optimize network
++    public boolean isPending = true;
++    public boolean queueImmunity;
++    // Paper end - Optimize network
+ 
+     // Paper start - add utility methods
+     public final net.minecraft.server.level.ServerPlayer getPlayer() {
+@@ -0,0 +0,0 @@ public class Connection extends SimpleChannelInboundHandler<Packet<?>> {
+     }
+ 
+     public void send(Packet<?> packet, @Nullable PacketSendListener callbacks, boolean flush) {
+-        if (this.isConnected()) {
+-            this.flushQueue();
++        // Paper start - Optimize network: Handle oversized packets better
++        final boolean connected = this.isConnected();
++        if (!connected && !this.preparing) {
++            return;
++        }
++
++        packet.onPacketDispatch(this.getPlayer());
++        if (connected && (InnerUtil.canSendImmediate(this, packet)
++            || (io.papermc.paper.util.MCUtil.isMainThread() && packet.isReady() && this.pendingActions.isEmpty()
++            && (packet.getExtraPackets() == null || packet.getExtraPackets().isEmpty())))) {
+             this.sendPacket(packet, callbacks, flush);
+         } else {
+-            this.pendingActions.add((networkmanager) -> {
+-                networkmanager.sendPacket(packet, callbacks, flush);
+-            });
+-        }
++            // Write the packets to the queue, then flush - antixray hooks there already
++            final java.util.List<Packet<?>> extraPackets = InnerUtil.buildExtraPackets(packet);
++            final boolean hasExtraPackets = extraPackets != null && !extraPackets.isEmpty();
++            if (!hasExtraPackets) {
++                this.pendingActions.add(new PacketSendAction(packet, callbacks, flush));
++            } else {
++                final java.util.List<PacketSendAction> actions = new java.util.ArrayList<>(1 + extraPackets.size());
++                actions.add(new PacketSendAction(packet, null, false)); // Delay the future listener until the end of the extra packets
++
++                for (int i = 0, len = extraPackets.size(); i < len;) {
++                    final Packet<?> extraPacket = extraPackets.get(i);
++                    final boolean end = ++i == len;
++                    actions.add(new PacketSendAction(extraPacket, end ? callbacks : null, end)); // Append listener to the end
++                }
++
++                this.pendingActions.addAll(actions);
++            }
+ 
++            this.flushQueue();
++            // Paper end - Optimize network
++        }
+     }
+ 
+     public void runOnceConnected(Consumer<Connection> task) {
+@@ -0,0 +0,0 @@ public class Connection extends SimpleChannelInboundHandler<Packet<?>> {
+             this.flushQueue();
+             task.accept(this);
+         } else {
+-            this.pendingActions.add(task);
++            this.pendingActions.add(new WrappedConsumer(task)); // Paper - Optimize network
+         }
+ 
+     }
+@@ -0,0 +0,0 @@ public class Connection extends SimpleChannelInboundHandler<Packet<?>> {
+     }
+ 
+     private void doSendPacket(Packet<?> packet, @Nullable PacketSendListener callbacks, boolean flush) {
++        // Paper start - Optimize network
++        final net.minecraft.server.level.ServerPlayer player = this.getPlayer();
++        if (!this.isConnected()) {
++            packet.onPacketDispatchFinish(player, null);
++            return;
++        }
++        try {
++        // Paper end - Optimize network
+         ChannelFuture channelfuture = flush ? this.channel.writeAndFlush(packet) : this.channel.write(packet);
+ 
+         if (callbacks != null) {
+@@ -0,0 +0,0 @@ public class Connection extends SimpleChannelInboundHandler<Packet<?>> {
+             });
+         }
+ 
++        // Paper start - Optimize network
++        if (packet.hasFinishListener()) {
++            channelfuture.addListener((ChannelFutureListener) channelFuture -> packet.onPacketDispatchFinish(player, channelFuture));
++        }
+         channelfuture.addListener(ChannelFutureListener.FIRE_EXCEPTION_ON_FAILURE);
++        } catch (final Exception e) {
++            LOGGER.error("NetworkException: {}", player, e);
++            this.disconnect(Component.translatable("disconnect.genericReason", "Internal Exception: " + e.getMessage()));
++            packet.onPacketDispatchFinish(player, null);
++        }
++        // Paper end - Optimize network
+     }
+ 
+     public void flushChannel() {
+         if (this.isConnected()) {
+             this.flush();
+         } else {
+-            this.pendingActions.add(Connection::flush);
++            this.pendingActions.add(new WrappedConsumer(Connection::flush)); // Paper - Optimize network
+         }
+ 
+     }
+@@ -0,0 +0,0 @@ public class Connection extends SimpleChannelInboundHandler<Packet<?>> {
+ 
+     }
+ 
+-    private void flushQueue() {
+-        if (this.channel != null && this.channel.isOpen()) {
+-            Queue queue = this.pendingActions;
+-
++    // Paper start - Optimize network: Rewrite this to be safer if ran off main thread
++    private boolean flushQueue() {
++        if (!this.isConnected()) {
++            return true;
++        }
++        if (io.papermc.paper.util.MCUtil.isMainThread()) {
++            return this.processQueue();
++        } else if (this.isPending) {
++            // Should only happen during login/status stages
+             synchronized (this.pendingActions) {
+-                Consumer consumer;
++                return this.processQueue();
++            }
++        }
++        return false;
++    }
++
++    private boolean processQueue() {
++        if (this.pendingActions.isEmpty()) {
++            return true;
++        }
+ 
+-                while ((consumer = (Consumer) this.pendingActions.poll()) != null) {
+-                    consumer.accept(this);
++        // If we are on main, we are safe here in that nothing else should be processing queue off main anymore
++        // But if we are not on main due to login/status, the parent is synchronized on packetQueue
++        final java.util.Iterator<WrappedConsumer> iterator = this.pendingActions.iterator();
++        while (iterator.hasNext()) {
++            final WrappedConsumer queued = iterator.next(); // poll -> peek
++
++            // Fix NPE (Spigot bug caused by handleDisconnection())
++            if (queued == null) {
++                return true;
++            }
++
++            if (queued.isConsumed()) {
++                continue;
++            }
++
++            if (queued instanceof PacketSendAction packetSendAction) {
++                final Packet<?> packet = packetSendAction.packet;
++                if (!packet.isReady()) {
++                    return false;
+                 }
++            }
+ 
++            iterator.remove();
++            if (queued.tryMarkConsumed()) {
++                queued.accept(this);
+             }
+         }
++        return true;
+     }
++    // Paper end - Optimize network
+ 
+     private static final int MAX_PER_TICK = io.papermc.paper.configuration.GlobalConfiguration.get().misc.maxJoinsPerTick; // Paper - Buffer joins to world
+     private static int joinAttemptsThisTick; // Paper - Buffer joins to world
+@@ -0,0 +0,0 @@ public class Connection extends SimpleChannelInboundHandler<Packet<?>> {
+     public void disconnect(Component disconnectReason) {
+         // Spigot Start
+         this.preparing = false;
++        this.clearPacketQueue(); // Paper - Optimize network
+         // Spigot End
+         if (this.channel == null) {
+             this.delayedDisconnect = disconnectReason;
+@@ -0,0 +0,0 @@ public class Connection extends SimpleChannelInboundHandler<Packet<?>> {
+     public void handleDisconnection() {
+         if (this.channel != null && !this.channel.isOpen()) {
+             if (this.disconnectionHandled) {
+-                Connection.LOGGER.warn("handleDisconnection() called twice");
++                // Connection.LOGGER.warn("handleDisconnection() called twice"); // Paper - Don't log useless message
+             } else {
+                 this.disconnectionHandled = true;
+                 PacketListener packetlistener = this.getPacketListener();
+@@ -0,0 +0,0 @@ public class Connection extends SimpleChannelInboundHandler<Packet<?>> {
+ 
+                     packetlistener1.onDisconnect(ichatbasecomponent);
+                 }
+-                this.pendingActions.clear(); // Free up packet queue.
++                this.clearPacketQueue(); // Paper - Optimize network
+                 // Paper start - Add PlayerConnectionCloseEvent
+                 final PacketListener packetListener = this.getPacketListener();
+                 if (packetListener instanceof net.minecraft.server.network.ServerCommonPacketListenerImpl commonPacketListener) {
+@@ -0,0 +0,0 @@ public class Connection extends SimpleChannelInboundHandler<Packet<?>> {
+     public void setBandwidthLogger(LocalSampleLogger log) {
+         this.bandwidthDebugMonitor = new BandwidthDebugMonitor(log);
+     }
++
++    // Paper start - Optimize network
++    public void clearPacketQueue() {
++        final net.minecraft.server.level.ServerPlayer player = getPlayer();
++        for (final Consumer<Connection> queuedAction : this.pendingActions) {
++            if (queuedAction instanceof PacketSendAction packetSendAction) {
++                final Packet<?> packet = packetSendAction.packet;
++                if (packet.hasFinishListener()) {
++                    packet.onPacketDispatchFinish(player, null);
++                }
++            }
++        }
++        this.pendingActions.clear();
++    }
++
++    private static class InnerUtil { // Attempt to hide these methods from ProtocolLib, so it doesn't accidently pick them up.
++
++        @Nullable
++        private static java.util.List<Packet<?>> buildExtraPackets(final Packet<?> packet) {
++            final java.util.List<Packet<?>> extra = packet.getExtraPackets();
++            if (extra == null || extra.isEmpty()) {
++                return null;
++            }
++
++            final java.util.List<Packet<?>> ret = new java.util.ArrayList<>(1 + extra.size());
++            buildExtraPackets0(extra, ret);
++            return ret;
++        }
++
++        private static void buildExtraPackets0(final java.util.List<Packet<?>> extraPackets, final java.util.List<Packet<?>> into) {
++            for (final Packet<?> extra : extraPackets) {
++                into.add(extra);
++                final java.util.List<Packet<?>> extraExtra = extra.getExtraPackets();
++                if (extraExtra != null && !extraExtra.isEmpty()) {
++                    buildExtraPackets0(extraExtra, into);
++                }
++            }
++        }
++
++        private static boolean canSendImmediate(final Connection networkManager, final net.minecraft.network.protocol.Packet<?> packet) {
++            return networkManager.isPending || networkManager.packetListener.protocol() != ConnectionProtocol.PLAY ||
++                packet instanceof net.minecraft.network.protocol.common.ClientboundKeepAlivePacket ||
++                packet instanceof net.minecraft.network.protocol.game.ClientboundPlayerChatPacket ||
++                packet instanceof net.minecraft.network.protocol.game.ClientboundSystemChatPacket ||
++                packet instanceof net.minecraft.network.protocol.game.ClientboundCommandSuggestionsPacket ||
++                packet instanceof net.minecraft.network.protocol.game.ClientboundSetTitleTextPacket ||
++                packet instanceof net.minecraft.network.protocol.game.ClientboundSetSubtitleTextPacket ||
++                packet instanceof net.minecraft.network.protocol.game.ClientboundSetActionBarTextPacket ||
++                packet instanceof net.minecraft.network.protocol.game.ClientboundSetTitlesAnimationPacket ||
++                packet instanceof net.minecraft.network.protocol.game.ClientboundClearTitlesPacket ||
++                packet instanceof net.minecraft.network.protocol.game.ClientboundSoundPacket ||
++                packet instanceof net.minecraft.network.protocol.game.ClientboundSoundEntityPacket ||
++                packet instanceof net.minecraft.network.protocol.game.ClientboundStopSoundPacket ||
++                packet instanceof net.minecraft.network.protocol.game.ClientboundLevelParticlesPacket ||
++                packet instanceof net.minecraft.network.protocol.game.ClientboundBossEventPacket;
++        }
++    }
++
++    private static class WrappedConsumer implements Consumer<Connection> {
++        private final Consumer<Connection> delegate;
++        private final java.util.concurrent.atomic.AtomicBoolean consumed = new java.util.concurrent.atomic.AtomicBoolean(false);
++
++        private WrappedConsumer(final Consumer<Connection> delegate) {
++            this.delegate = delegate;
++        }
++
++        @Override
++        public void accept(final Connection connection) {
++            this.delegate.accept(connection);
++        }
++
++        public boolean tryMarkConsumed() {
++            return consumed.compareAndSet(false, true);
++        }
++
++        public boolean isConsumed() {
++            return consumed.get();
++        }
++    }
++
++    private static final class PacketSendAction extends WrappedConsumer {
++        private final Packet<?> packet;
++
++        private PacketSendAction(final Packet<?> packet, @Nullable final PacketSendListener packetSendListener, final boolean flush) {
++            super(connection -> connection.sendPacket(packet, packetSendListener, flush));
++            this.packet = packet;
++        }
++    }
++    // Paper end - Optimize network
+ }
+diff --git a/src/main/java/net/minecraft/network/protocol/Packet.java b/src/main/java/net/minecraft/network/protocol/Packet.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/network/protocol/Packet.java
++++ b/src/main/java/net/minecraft/network/protocol/Packet.java
+@@ -0,0 +0,0 @@ public interface Packet<T extends PacketListener> {
+     static <B extends ByteBuf, T extends Packet<?>> StreamCodec<B, T> codec(StreamMemberEncoder<B, T> encoder, StreamDecoder<B, T> decoder) {
+         return StreamCodec.ofMember(encoder, decoder);
+     }
++
++    // Paper start
++    /**
++     * @param player Null if not at PLAY stage yet
++     */
++    default void onPacketDispatch(@Nullable net.minecraft.server.level.ServerPlayer player) {
++    }
++
++    /**
++     * @param player Null if not at PLAY stage yet
++     * @param future Can be null if packet was cancelled
++     */
++    default void onPacketDispatchFinish(@Nullable net.minecraft.server.level.ServerPlayer player, @Nullable io.netty.channel.ChannelFuture future) {}
++
++    default boolean hasFinishListener() {
++        return false;
++    }
++
++    default boolean isReady() {
++        return true;
++    }
++
++    @Nullable
++    default java.util.List<Packet<?>> getExtraPackets() {
++        return null;
++    }
++    // Paper end
+ }
+diff --git a/src/main/java/net/minecraft/server/network/ServerConnectionListener.java b/src/main/java/net/minecraft/server/network/ServerConnectionListener.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/server/network/ServerConnectionListener.java
++++ b/src/main/java/net/minecraft/server/network/ServerConnectionListener.java
+@@ -0,0 +0,0 @@ public class ServerConnectionListener {
+     final List<Connection> connections = Collections.synchronizedList(Lists.newArrayList());
+     // Paper start - prevent blocking on adding a new connection while the server is ticking
+     private final java.util.Queue<Connection> pending = new java.util.concurrent.ConcurrentLinkedQueue<>();
++    private static final boolean disableFlushConsolidation = Boolean.getBoolean("Paper.disableFlushConsolidate"); // Paper - Optimize network
+     private final void addPending() {
+         Connection connection;
+         while ((connection = pending.poll()) != null) {
+             connections.add(connection);
++            connection.isPending = false; // Paper - Optimize network
+         }
+     }
+     // Paper end - prevent blocking on adding a new connection while the server is ticking
+@@ -0,0 +0,0 @@ public class ServerConnectionListener {
+                         ;
+                     }
+ 
++                    if (!disableFlushConsolidation) channel.pipeline().addFirst(new io.netty.handler.flush.FlushConsolidationHandler()); // Paper - Optimize network
+                     ChannelPipeline channelpipeline = channel.pipeline().addLast("timeout", new ReadTimeoutHandler(30));
+ 
+                     if (ServerConnectionListener.this.server.repliesToStatus()) {

patches/server/Optimize-isInWorldBounds-and-getBlockState-for-inlin.patch

@@ -0,0 +1,99 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Aikar <aikar@aikar.co>
+Date: Thu, 3 Mar 2016 02:07:55 -0600
+Subject: [PATCH] Optimize isInWorldBounds and getBlockState for inlining
+
+Hot methods, so reduce # of instructions for the method.
+
+Move is valid location test to the BlockPosition class so that it can access local variables.
+
+Replace all calls to the new place to the unnecessary forward.
+
+Optimize getType and getBlockData to manually inline and optimize the calls
+
+diff --git a/src/main/java/net/minecraft/core/Vec3i.java b/src/main/java/net/minecraft/core/Vec3i.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/core/Vec3i.java
++++ b/src/main/java/net/minecraft/core/Vec3i.java
+@@ -0,0 +0,0 @@ public class Vec3i implements Comparable<Vec3i> {
+         );
+     }
+ 
++    // Paper start
++    public final boolean isInsideBuildHeightAndWorldBoundsHorizontal(net.minecraft.world.level.LevelHeightAccessor levelHeightAccessor) {
++        return getX() >= -30000000 && getZ() >= -30000000 && getX() < 30000000 && getZ() < 30000000 && !levelHeightAccessor.isOutsideBuildHeight(getY());
++    }
++    // Paper end
++
+     public Vec3i(int x, int y, int z) {
+         this.x = x;
+         this.y = y;
+diff --git a/src/main/java/net/minecraft/world/level/Level.java b/src/main/java/net/minecraft/world/level/Level.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/world/level/Level.java
++++ b/src/main/java/net/minecraft/world/level/Level.java
+@@ -0,0 +0,0 @@ public abstract class Level implements LevelAccessor, AutoCloseable {
+     // Paper end
+ 
+     public boolean isInWorldBounds(BlockPos pos) {
+-        return !this.isOutsideBuildHeight(pos) && Level.isInWorldBoundsHorizontal(pos);
++        return pos.isInsideBuildHeightAndWorldBoundsHorizontal(this); // Paper - use better/optimized check
+     }
+ 
+     public static boolean isInSpawnableBounds(BlockPos pos) {
+diff --git a/src/main/java/net/minecraft/world/level/chunk/ChunkAccess.java b/src/main/java/net/minecraft/world/level/chunk/ChunkAccess.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/world/level/chunk/ChunkAccess.java
++++ b/src/main/java/net/minecraft/world/level/chunk/ChunkAccess.java
+@@ -0,0 +0,0 @@ public abstract class ChunkAccess implements BlockGetter, BiomeManager.NoiseBiom
+         return GameEventListenerRegistry.NOOP;
+     }
+ 
++    public abstract BlockState getBlockState(final int x, final int y, final int z); // Paper
+     @Nullable
+     public abstract BlockState setBlockState(BlockPos pos, BlockState state, boolean moved);
+ 
+diff --git a/src/main/java/net/minecraft/world/level/chunk/ImposterProtoChunk.java b/src/main/java/net/minecraft/world/level/chunk/ImposterProtoChunk.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/world/level/chunk/ImposterProtoChunk.java
++++ b/src/main/java/net/minecraft/world/level/chunk/ImposterProtoChunk.java
+@@ -0,0 +0,0 @@ public class ImposterProtoChunk extends ProtoChunk {
+     public BlockState getBlockState(BlockPos pos) {
+         return this.wrapped.getBlockState(pos);
+     }
++    // Paper start
++    @Override
++    public final BlockState getBlockState(final int x, final int y, final int z) {
++        return this.wrapped.getBlockStateFinal(x, y, z);
++    }
++    // Paper end
+ 
+     @Override
+     public FluidState getFluidState(BlockPos pos) {
+diff --git a/src/main/java/net/minecraft/world/level/chunk/ProtoChunk.java b/src/main/java/net/minecraft/world/level/chunk/ProtoChunk.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/world/level/chunk/ProtoChunk.java
++++ b/src/main/java/net/minecraft/world/level/chunk/ProtoChunk.java
+@@ -0,0 +0,0 @@ public class ProtoChunk extends ChunkAccess {
+ 
+     @Override
+     public BlockState getBlockState(BlockPos pos) {
+-        int i = pos.getY();
+-        if (this.isOutsideBuildHeight(i)) {
++        // Paper start
++        return getBlockState(pos.getX(), pos.getY(), pos.getZ());
++    }
++    public BlockState getBlockState(final int x, final int y, final int z) {
++        if (this.isOutsideBuildHeight(y)) {
+             return Blocks.VOID_AIR.defaultBlockState();
+         } else {
+-            LevelChunkSection levelChunkSection = this.getSection(this.getSectionIndex(i));
+-            return levelChunkSection.hasOnlyAir() ? Blocks.AIR.defaultBlockState() : levelChunkSection.getBlockState(pos.getX() & 15, i & 15, pos.getZ() & 15);
++            LevelChunkSection levelChunkSection = this.getSections()[this.getSectionIndex(y)];
++            return levelChunkSection.hasOnlyAir() ? Blocks.AIR.defaultBlockState() : levelChunkSection.getBlockState(x & 15, y & 15, z & 15);
+         }
+     }
++    // Paper end
+ 
+     @Override
+     public FluidState getFluidState(BlockPos pos) {

patches/server/Optional-per-player-mob-spawns.patch

@@ -0,0 +1,255 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: kickash32 <kickash32@gmail.com>
+Date: Mon, 19 Aug 2019 01:27:58 +0500
+Subject: [PATCH] Optional per player mob spawns
+
+
+diff --git a/src/main/java/net/minecraft/server/level/ChunkMap.java b/src/main/java/net/minecraft/server/level/ChunkMap.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/server/level/ChunkMap.java
++++ b/src/main/java/net/minecraft/server/level/ChunkMap.java
+@@ -0,0 +0,0 @@ public class ChunkMap extends ChunkStorage implements ChunkHolder.PlayerProvider
+         });
+     }
+ 
++    // Paper start - Optional per player mob spawns
++    public void updatePlayerMobTypeMap(final Entity entity) {
++        if (!this.level.paperConfig().entities.spawning.perPlayerMobSpawns) {
++            return;
++        }
++        int index = entity.getType().getCategory().ordinal();
++
++        final com.destroystokyo.paper.util.maplist.ReferenceList<ServerPlayer> inRange =
++            this.getNearbyPlayers().getPlayers(entity.chunkPosition(), io.papermc.paper.util.player.NearbyPlayers.NearbyMapType.TICK_VIEW_DISTANCE);
++        if (inRange == null) {
++            return;
++        }
++        final Object[] backingSet = inRange.getRawData();
++        for (int i = 0, len = inRange.size(); i < len; i++) {
++            ++((ServerPlayer)backingSet[i]).mobCounts[index];
++        }
++    }
++
+     public int getMobCountNear(final ServerPlayer player, final net.minecraft.world.entity.MobCategory mobCategory) {
+-        return -1;
++        return player.mobCounts[mobCategory.ordinal()];
+     }
++    // Paper end - Optional per player mob spawns
+ 
+     private static double euclideanDistanceSquared(ChunkPos pos, Entity entity) {
+         double d0 = (double) SectionPos.sectionToBlockCoord(pos.x, 8);
+diff --git a/src/main/java/net/minecraft/server/level/ServerChunkCache.java b/src/main/java/net/minecraft/server/level/ServerChunkCache.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/server/level/ServerChunkCache.java
++++ b/src/main/java/net/minecraft/server/level/ServerChunkCache.java
+@@ -0,0 +0,0 @@ public class ServerChunkCache extends ChunkSource {
+                 gameprofilerfiller.popPush("naturalSpawnCount");
+                 this.level.timings.countNaturalMobs.startTiming(); // Paper - timings
+                 int k = this.distanceManager.getNaturalSpawnChunkCount();
+-                NaturalSpawner.SpawnState spawnercreature_d = NaturalSpawner.createState(k, this.level.getAllEntities(), this::getFullChunk, new LocalMobCapCalculator(this.chunkMap));
++                // Paper start - Optional per player mob spawns
++                int naturalSpawnChunkCount = k;
++                NaturalSpawner.SpawnState spawnercreature_d; // moved down
++                if ((this.spawnFriendlies || this.spawnEnemies) && this.level.paperConfig().entities.spawning.perPlayerMobSpawns) { // don't count mobs when animals and monsters are disabled
++                    // re-set mob counts
++                    for (ServerPlayer player : this.level.players) {
++                        Arrays.fill(player.mobCounts, 0);
++                    }
++                    spawnercreature_d = NaturalSpawner.createState(naturalSpawnChunkCount, this.level.getAllEntities(), this::getFullChunk, null, true);
++                } else {
++                    spawnercreature_d = NaturalSpawner.createState(naturalSpawnChunkCount, this.level.getAllEntities(), this::getFullChunk, !this.level.paperConfig().entities.spawning.perPlayerMobSpawns ? new LocalMobCapCalculator(this.chunkMap) : null, false);
++                }
++                // Paper end - Optional per player mob spawns
+                 this.level.timings.countNaturalMobs.stopTiming(); // Paper - timings
+ 
+                 this.lastSpawnState = spawnercreature_d;
+diff --git a/src/main/java/net/minecraft/server/level/ServerPlayer.java b/src/main/java/net/minecraft/server/level/ServerPlayer.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/server/level/ServerPlayer.java
++++ b/src/main/java/net/minecraft/server/level/ServerPlayer.java
+@@ -0,0 +0,0 @@ public class ServerPlayer extends Player {
+     public boolean queueHealthUpdatePacket;
+     public net.minecraft.network.protocol.game.ClientboundSetHealthPacket queuedHealthUpdatePacket;
+     // Paper end - cancellable death event
++    // Paper start - Optional per player mob spawns
++    public static final int MOBCATEGORY_TOTAL_ENUMS = net.minecraft.world.entity.MobCategory.values().length;
++    public final int[] mobCounts = new int[MOBCATEGORY_TOTAL_ENUMS]; // Paper
++    // Paper end - Optional per player mob spawns
+ 
+     // CraftBukkit start
+     public CraftPlayer.TransferCookieConnection transferCookieConnection;
+diff --git a/src/main/java/net/minecraft/world/level/NaturalSpawner.java b/src/main/java/net/minecraft/world/level/NaturalSpawner.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/world/level/NaturalSpawner.java
++++ b/src/main/java/net/minecraft/world/level/NaturalSpawner.java
+@@ -0,0 +0,0 @@ public final class NaturalSpawner {
+     private NaturalSpawner() {}
+ 
+     public static NaturalSpawner.SpawnState createState(int spawningChunkCount, Iterable<Entity> entities, NaturalSpawner.ChunkGetter chunkSource, LocalMobCapCalculator densityCapper) {
++        // Paper start - Optional per player mob spawns
++        return createState(spawningChunkCount, entities, chunkSource, densityCapper, false);
++    }
++
++    public static NaturalSpawner.SpawnState createState(int spawningChunkCount, Iterable<Entity> entities, NaturalSpawner.ChunkGetter chunkSource, LocalMobCapCalculator densityCapper, boolean countMobs) {
++        // Paper end - Optional per player mob spawns
+         PotentialCalculator spawnercreatureprobabilities = new PotentialCalculator();
+         Object2IntOpenHashMap<MobCategory> object2intopenhashmap = new Object2IntOpenHashMap();
+         Iterator iterator = entities.iterator();
+@@ -0,0 +0,0 @@ public final class NaturalSpawner {
+                         spawnercreatureprobabilities.addCharge(entity.blockPosition(), biomesettingsmobs_b.charge());
+                     }
+ 
+-                    if (entity instanceof Mob) {
++                    if (densityCapper != null && entity instanceof Mob) { // Paper - Optional per player mob spawns
+                         densityCapper.addMob(chunk.getPos(), enumcreaturetype);
+                     }
+ 
+                     object2intopenhashmap.addTo(enumcreaturetype, 1);
++                    // Paper start - Optional per player mob spawns
++                    if (countMobs) {
++                        chunk.level.getChunkSource().chunkMap.updatePlayerMobTypeMap(entity);
++                    }
++                    // Paper end - Optional per player mob spawns
+                 });
+             }
+         }
+@@ -0,0 +0,0 @@ public final class NaturalSpawner {
+                 continue;
+             }
+ 
+-            if ((spawnAnimals || !enumcreaturetype.isFriendly()) && (spawnMonsters || enumcreaturetype.isFriendly()) && (rareSpawn || !enumcreaturetype.isPersistent()) && info.canSpawnForCategory(enumcreaturetype, chunk.getPos(), limit)) {
++            // Paper start - Optional per player mob spawns; only allow spawns upto the limit per chunk and update count afterwards
++            int currEntityCount = info.mobCategoryCounts.getInt(enumcreaturetype);
++            int k1 = limit * info.getSpawnableChunkCount() / NaturalSpawner.MAGIC_NUMBER;
++            int difference = k1 - currEntityCount;
++
++            if (world.paperConfig().entities.spawning.perPlayerMobSpawns) {
++                int minDiff = Integer.MAX_VALUE;
++                final com.destroystokyo.paper.util.maplist.ReferenceList<net.minecraft.server.level.ServerPlayer> inRange =
++                    world.chunkSource.chunkMap.getNearbyPlayers().getPlayers(chunk.getPos(), io.papermc.paper.util.player.NearbyPlayers.NearbyMapType.TICK_VIEW_DISTANCE);
++                if (inRange != null) {
++                    final Object[] backingSet = inRange.getRawData();
++                    for (int k = 0, len = inRange.size(); k < len; k++) {
++                        minDiff = Math.min(limit - world.getChunkSource().chunkMap.getMobCountNear((net.minecraft.server.level.ServerPlayer)backingSet[k], enumcreaturetype), minDiff);
++                    }
++                }
++                difference = (minDiff == Integer.MAX_VALUE) ? 0 : minDiff;
++            }
++            if ((spawnAnimals || !enumcreaturetype.isFriendly()) && (spawnMonsters || enumcreaturetype.isFriendly()) && (rareSpawn || !enumcreaturetype.isPersistent()) && difference > 0) {
++                // Paper end - Optional per player mob spawns
+                 // CraftBukkit end
+                 Objects.requireNonNull(info);
+                 NaturalSpawner.SpawnPredicate spawnercreature_c = info::canSpawn;
+ 
+                 Objects.requireNonNull(info);
+-                NaturalSpawner.spawnCategoryForChunk(enumcreaturetype, world, chunk, spawnercreature_c, info::afterSpawn);
++                // Paper start - Optional per player mob spawns
++                int spawnCount = NaturalSpawner.spawnCategoryForChunk(enumcreaturetype, world, chunk, spawnercreature_c, info::afterSpawn,
++                    difference, world.paperConfig().entities.spawning.perPlayerMobSpawns ? world.getChunkSource().chunkMap::updatePlayerMobTypeMap : null);
++                info.mobCategoryCounts.mergeInt(enumcreaturetype, spawnCount, Integer::sum);
++                // Paper end - Optional per player mob spawns
+             }
+         }
+ 
+@@ -0,0 +0,0 @@ public final class NaturalSpawner {
+     // Paper end - Add mobcaps commands
+ 
+     public static void spawnCategoryForChunk(MobCategory group, ServerLevel world, LevelChunk chunk, NaturalSpawner.SpawnPredicate checker, NaturalSpawner.AfterSpawnCallback runner) {
++        // Paper start - Optional per player mob spawns
++        spawnCategoryForChunk(group, world, chunk, checker, runner, Integer.MAX_VALUE, null);
++    }
++    public static int spawnCategoryForChunk(MobCategory group, ServerLevel world, LevelChunk chunk, NaturalSpawner.SpawnPredicate checker, NaturalSpawner.AfterSpawnCallback runner, int maxSpawns, Consumer<Entity> trackEntity) {
++        // Paper end - Optional per player mob spawns
+         BlockPos blockposition = NaturalSpawner.getRandomPosWithin(world, chunk);
+ 
+         if (blockposition.getY() >= world.getMinBuildHeight() + 1) {
+-            NaturalSpawner.spawnCategoryForPosition(group, world, chunk, blockposition, checker, runner);
++            return NaturalSpawner.spawnCategoryForPosition(group, world, chunk, blockposition, checker, runner, maxSpawns, trackEntity); // Paper - Optional per player mob spawns
+         }
++        return 0; // Paper - Optional per player mob spawns
+     }
+ 
+     @VisibleForDebug
+@@ -0,0 +0,0 @@ public final class NaturalSpawner {
+         });
+     }
+ 
++    // Paper start - Optional per player mob spawns
+     public static void spawnCategoryForPosition(MobCategory group, ServerLevel world, ChunkAccess chunk, BlockPos pos, NaturalSpawner.SpawnPredicate checker, NaturalSpawner.AfterSpawnCallback runner) {
++        spawnCategoryForPosition(group, world,chunk, pos, checker, runner, Integer.MAX_VALUE, null);
++    }
++    public static int spawnCategoryForPosition(MobCategory group, ServerLevel world, ChunkAccess chunk, BlockPos pos, NaturalSpawner.SpawnPredicate checker, NaturalSpawner.AfterSpawnCallback runner, int maxSpawns, Consumer<Entity> trackEntity) {
++    // Paper end - Optional per player mob spawns
+         StructureManager structuremanager = world.structureManager();
+         ChunkGenerator chunkgenerator = world.getChunkSource().getGenerator();
+         int i = pos.getY();
+         BlockState iblockdata = world.getBlockStateIfLoadedAndInBounds(pos); // Paper - don't load chunks for mob spawn
++        int j = 0; // Paper - Optional per player mob spawns; moved up
+ 
+         if (iblockdata != null && !iblockdata.isRedstoneConductor(chunk, pos)) { // Paper - don't load chunks for mob spawn
+             BlockPos.MutableBlockPos blockposition_mutableblockposition = new BlockPos.MutableBlockPos();
+-            int j = 0;
++            //int j = 0; // Paper - Optional per player mob spawns; moved up
+             int k = 0;
+ 
+             while (k < 3) {
+@@ -0,0 +0,0 @@ public final class NaturalSpawner {
+                                     // Paper start - PreCreatureSpawnEvent
+                                     PreSpawnStatus doSpawning = isValidSpawnPostitionForType(world, group, structuremanager, chunkgenerator, biomesettingsmobs_c, blockposition_mutableblockposition, d2);
+                                     if (doSpawning == PreSpawnStatus.ABORT) {
+-                                        return;
++                                        return j; // Paper - Optional per player mob spawns
+                                     }
+                                     if (doSpawning == PreSpawnStatus.SUCCESS && checker.test(biomesettingsmobs_c.type, blockposition_mutableblockposition, chunk)) {
+                                         // Paper end - PreCreatureSpawnEvent
+                                         Mob entityinsentient = NaturalSpawner.getMobForSpawn(world, biomesettingsmobs_c.type);
+ 
+                                         if (entityinsentient == null) {
+-                                            return;
++                                            return j; // Paper - Optional per player mob spawns
+                                         }
+ 
+                                         entityinsentient.moveTo(d0, (double) i, d1, world.random.nextFloat() * 360.0F, 0.0F);
+@@ -0,0 +0,0 @@ public final class NaturalSpawner {
+                                                 ++j;
+                                                 ++k1;
+                                                 runner.run(entityinsentient, chunk);
++                                                // Paper start - Optional per player mob spawns
++                                                if (trackEntity != null) {
++                                                    trackEntity.accept(entityinsentient);
++                                                }
++                                                // Paper end - Optional per player mob spawns
+                                             }
+                                             // CraftBukkit end
+-                                            if (j >= entityinsentient.getMaxSpawnClusterSize()) {
+-                                                return;
++                                            if (j >= entityinsentient.getMaxSpawnClusterSize() || j >= maxSpawns) { // Paper - Optional per player mob spawns
++                                                return j; // Paper - Optional per player mob spawns
+                                             }
+ 
+                                             if (entityinsentient.isMaxGroupSizeReached(k1)) {
+@@ -0,0 +0,0 @@ public final class NaturalSpawner {
+             }
+ 
+         }
++        return j; // Paper - Optional per player mob spawns
+     }
+ 
+     private static boolean isRightDistanceToPlayerAndSpawnPoint(ServerLevel world, ChunkAccess chunk, BlockPos.MutableBlockPos pos, double squaredDistance) {
+@@ -0,0 +0,0 @@ public final class NaturalSpawner {
+             MobCategory enumcreaturetype = entitytypes.getCategory();
+ 
+             this.mobCategoryCounts.addTo(enumcreaturetype, 1);
+-            this.localMobCapCalculator.addMob(new ChunkPos(blockposition), enumcreaturetype);
++            if (this.localMobCapCalculator != null) this.localMobCapCalculator.addMob(new ChunkPos(blockposition), enumcreaturetype); // Paper - Optional per player mob spawns
+         }
+ 
+         public int getSpawnableChunkCount() {
+@@ -0,0 +0,0 @@ public final class NaturalSpawner {
+             int i = limit * this.spawnableChunkCount / NaturalSpawner.MAGIC_NUMBER;
+             // CraftBukkit end
+ 
++            if (this.localMobCapCalculator == null) return this.mobCategoryCounts.getInt(enumcreaturetype) < i; // Paper - Optional per player mob spawns
+             return this.mobCategoryCounts.getInt(enumcreaturetype) >= i ? false : this.localMobCapCalculator.canSpawn(enumcreaturetype, chunkcoordintpair);
+         }
+     }

patches/server/Strip-raytracing-for-EntityLiving-hasLineOfSight.patch

@@ -0,0 +1,158 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Paul Sauve <paul@technove.co>
+Date: Sat, 31 Oct 2020 18:43:02 -0500
+Subject: [PATCH] Strip raytracing for EntityLiving#hasLineOfSight
+
+The BlockGetter#clip method is very wasteful in both allocations,
+and in logic. While EntityLiving#hasLineOfSight provides static
+parameters for collisions with blocks and fluids, the method still does
+a lot of dynamic checks for both of these, which result in extra work.
+As well, since the fluid collision option is set to NONE, the entire
+fluid collision system is completely unneeded, yet used anyways.
+
+Copyright (C) 2020 Technove LLC
+
+This program is free software: you can redistribute it and/or modify
+it under the terms of the GNU General Public License as published by
+the Free Software Foundation, either version 3 of the License, or
+(at your option) any later version.
+
+This program 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 General Public License for more details.
+
+You should have received a copy of the GNU General Public License
+along with this program.  If not, see <http://www.gnu.org/licenses/>.
+
+diff --git a/src/main/java/net/minecraft/world/entity/LivingEntity.java b/src/main/java/net/minecraft/world/entity/LivingEntity.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/world/entity/LivingEntity.java
++++ b/src/main/java/net/minecraft/world/entity/LivingEntity.java
+@@ -0,0 +0,0 @@ public abstract class LivingEntity extends Entity implements Attackable {
+             Vec3 vec3d1 = new Vec3(entity.getX(), entity.getEyeY(), entity.getZ());
+ 
+             // Paper - diff on change - used in CraftLivingEntity#hasLineOfSight(Location) and CraftWorld#lineOfSightExists
+-            return vec3d1.distanceToSqr(vec3d) > 128.0D * 128.0D ? false : this.level().clip(new ClipContext(vec3d, vec3d1, ClipContext.Block.COLLIDER, ClipContext.Fluid.NONE, this)).getType() == HitResult.Type.MISS; // Paper - Perf: Use distance squared
++            return vec3d1.distanceToSqr(vec3d) > 128.0D * 128.0D ? false : this.level().clipDirect(vec3d, vec3d1, net.minecraft.world.phys.shapes.CollisionContext.of(this)) == HitResult.Type.MISS; // Paper - Perf: Use distance squared & strip raytracing
+         }
+     }
+ 
+diff --git a/src/main/java/net/minecraft/world/level/BlockGetter.java b/src/main/java/net/minecraft/world/level/BlockGetter.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/world/level/BlockGetter.java
++++ b/src/main/java/net/minecraft/world/level/BlockGetter.java
+@@ -0,0 +0,0 @@ public interface BlockGetter extends LevelHeightAccessor {
+         });
+     }
+ 
++    // Paper start - Broken down variant of the method below, used by Level#clipDirect
++    @Nullable
++    default BlockHitResult.Type clipDirect(Vec3 start, Vec3 end, BlockPos pos, BlockState state, net.minecraft.world.phys.shapes.CollisionContext collisionContext) {
++        if (state.isAir()) {
++            return null;
++        }
++
++        final VoxelShape voxelshape = ClipContext.Block.COLLIDER.get(state, this, pos, collisionContext);
++        final BlockHitResult hitResult = this.clipWithInteractionOverride(start, end, pos, voxelshape, state);
++        return hitResult == null ? null : hitResult.getType();
++    }
++    // Paper end
+     // CraftBukkit start - moved block handling into separate method for use by Block#rayTrace
+     default BlockHitResult clip(ClipContext raytrace1, BlockPos blockposition) {
+         // Paper start - Add predicate for blocks when raytracing
+diff --git a/src/main/java/net/minecraft/world/level/Level.java b/src/main/java/net/minecraft/world/level/Level.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/world/level/Level.java
++++ b/src/main/java/net/minecraft/world/level/Level.java
+@@ -0,0 +0,0 @@ public abstract class Level implements LevelAccessor, AutoCloseable {
+         return null;
+     }
+ 
+-    // Paper start
++    // Paper start - Broken down method of raytracing for EntityLiving#hasLineOfSight, replaces BlockGetter#clip(CollisionContext)
+     public net.minecraft.world.phys.BlockHitResult.Type clipDirect(Vec3 start, Vec3 end, net.minecraft.world.phys.shapes.CollisionContext context) {
+-        // To be patched over
+-        return this.clip(new ClipContext(start, end, ClipContext.Block.COLLIDER, ClipContext.Fluid.NONE, context)).getType();
++        // most of this code comes from BlockGetter#clip(CollisionContext, BiFunction, Function), but removes the needless functions
++        if (start.equals(end)) {
++            return net.minecraft.world.phys.BlockHitResult.Type.MISS;
++        }
++
++        final double endX = Mth.lerp(-1.0E-7D, end.x, start.x);
++        final double endY = Mth.lerp(-1.0E-7D, end.y, start.y);
++        final double endZ = Mth.lerp(-1.0E-7D, end.z, start.z);
++
++        final double startX = Mth.lerp(-1.0E-7D, start.x, end.x);
++        final double startY = Mth.lerp(-1.0E-7D, start.y, end.y);
++        final double startZ = Mth.lerp(-1.0E-7D, start.z, end.z);
++
++        int currentX = Mth.floor(startX);
++        int currentY = Mth.floor(startY);
++        int currentZ = Mth.floor(startZ);
++
++        final BlockPos.MutableBlockPos currentBlock = new BlockPos.MutableBlockPos(currentX, currentY, currentZ);
++
++        LevelChunk chunk = this.getChunkIfLoaded(currentBlock);
++        if (chunk == null) {
++            return net.minecraft.world.phys.BlockHitResult.Type.MISS;
++        }
++
++        final net.minecraft.world.phys.BlockHitResult.Type initialCheck = this.clipDirect(start, end, currentBlock, chunk.getBlockState(currentBlock), context);
++        if (initialCheck != null) {
++            return initialCheck;
++        }
++
++        final double diffX = endX - startX;
++        final double diffY = endY - startY;
++        final double diffZ = endZ - startZ;
++
++        final int xDirection = Mth.sign(diffX);
++        final int yDirection = Mth.sign(diffY);
++        final int zDirection = Mth.sign(diffZ);
++
++        final double normalizedX = xDirection == 0 ? Double.MAX_VALUE : (double) xDirection / diffX;
++        final double normalizedY = yDirection == 0 ? Double.MAX_VALUE : (double) yDirection / diffY;
++        final double normalizedZ = zDirection == 0 ? Double.MAX_VALUE : (double) zDirection / diffZ;
++
++        double normalizedXDirection = normalizedX * (xDirection > 0 ? 1.0D - Mth.frac(startX) : Mth.frac(startX));
++        double normalizedYDirection = normalizedY * (yDirection > 0 ? 1.0D - Mth.frac(startY) : Mth.frac(startY));
++        double normalizedZDirection = normalizedZ * (zDirection > 0 ? 1.0D - Mth.frac(startZ) : Mth.frac(startZ));
++
++        net.minecraft.world.phys.BlockHitResult.Type result;
++
++        do {
++            if (normalizedXDirection > 1.0D && normalizedYDirection > 1.0D && normalizedZDirection > 1.0D) {
++                return net.minecraft.world.phys.BlockHitResult.Type.MISS;
++            }
++
++            if (normalizedXDirection < normalizedYDirection) {
++                if (normalizedXDirection < normalizedZDirection) {
++                    currentX += xDirection;
++                    normalizedXDirection += normalizedX;
++                } else {
++                    currentZ += zDirection;
++                    normalizedZDirection += normalizedZ;
++                }
++            } else if (normalizedYDirection < normalizedZDirection) {
++                currentY += yDirection;
++                normalizedYDirection += normalizedY;
++            } else {
++                currentZ += zDirection;
++                normalizedZDirection += normalizedZ;
++            }
++
++            currentBlock.set(currentX, currentY, currentZ);
++            if (chunk.getPos().x != currentBlock.getX() >> 4 || chunk.getPos().z != currentBlock.getZ() >> 4) {
++                chunk = this.getChunkIfLoaded(currentBlock);
++                if (chunk == null) {
++                    return net.minecraft.world.phys.BlockHitResult.Type.MISS;
++                }
++            }
++            result = this.clipDirect(start, end, currentBlock, chunk.getBlockState(currentBlock), context);
++        } while (result == null);
++
++        return result;
+     }
+     // Paper end
+ 

patches/server/incremental-chunk-and-player-saving.patch

@@ -0,0 +1,167 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Shane Freeder <theboyetronic@gmail.com>
+Date: Sun, 9 Jun 2019 03:53:22 +0100
+Subject: [PATCH] incremental chunk and player saving
+
+
+diff --git a/src/main/java/net/minecraft/server/MinecraftServer.java b/src/main/java/net/minecraft/server/MinecraftServer.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/server/MinecraftServer.java
++++ b/src/main/java/net/minecraft/server/MinecraftServer.java
+@@ -0,0 +0,0 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
+ 
+         try {
+             this.isSaving = true;
+-            this.getPlayerList().saveAll();
++            this.getPlayerList().saveAll(); // Paper - Incremental chunk and player saving; diff on change
+             flag3 = this.saveAllChunks(suppressLogs, flush, force);
+         } finally {
+             this.isSaving = false;
+@@ -0,0 +0,0 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
+         }
+ 
+         --this.ticksUntilAutosave;
+-        // CraftBukkit start
+-        if (this.autosavePeriod > 0 && this.ticksUntilAutosave <= 0) {
+-            this.ticksUntilAutosave = this.autosavePeriod;
+-            // CraftBukkit end
+-            MinecraftServer.LOGGER.debug("Autosave started");
+-            this.profiler.push("save");
+-            this.saveEverything(true, false, false);
+-            this.profiler.pop();
+-            MinecraftServer.LOGGER.debug("Autosave finished");
++        // Paper start - Incremental chunk and player saving
++        int playerSaveInterval = io.papermc.paper.configuration.GlobalConfiguration.get().playerAutoSave.rate;
++        if (playerSaveInterval < 0) {
++            playerSaveInterval = autosavePeriod;
+         }
++        this.profiler.push("save");
++        final boolean fullSave = autosavePeriod > 0 && this.tickCount % autosavePeriod == 0;
++        try {
++            this.isSaving = true;
++            if (playerSaveInterval > 0) {
++                this.playerList.saveAll(playerSaveInterval);
++            }
++            for (ServerLevel level : this.getAllLevels()) {
++                if (level.paperConfig().chunks.autoSaveInterval.value() > 0) {
++                    level.saveIncrementally(fullSave);
++                }
++            }
++        } finally {
++            this.isSaving = false;
++        }
++        this.profiler.pop();
++        // Paper end - Incremental chunk and player saving
+         io.papermc.paper.util.CachedLists.reset(); // Paper
+         // Paper start - move executeAll() into full server tick timing
+         try (co.aikar.timings.Timing ignored = MinecraftTimings.processTasksTimer.startTiming()) {
+diff --git a/src/main/java/net/minecraft/server/level/ServerChunkCache.java b/src/main/java/net/minecraft/server/level/ServerChunkCache.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/server/level/ServerChunkCache.java
++++ b/src/main/java/net/minecraft/server/level/ServerChunkCache.java
+@@ -0,0 +0,0 @@ public class ServerChunkCache extends ChunkSource {
+         } // Paper - Timings
+     }
+ 
++    // Paper start - Incremental chunk and player saving; duplicate save, but call incremental
++    public void saveIncrementally() {
++        this.runDistanceManagerUpdates();
++        try (co.aikar.timings.Timing timed = level.timings.chunkSaveData.startTiming()) { // Paper - Timings
++            this.chunkMap.saveIncrementally();
++        } // Paper - Timings
++    }
++    // Paper end - Incremental chunk and player saving
++
+     @Override
+     public void close() throws IOException {
+         // CraftBukkit start
+diff --git a/src/main/java/net/minecraft/server/level/ServerLevel.java b/src/main/java/net/minecraft/server/level/ServerLevel.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/server/level/ServerLevel.java
++++ b/src/main/java/net/minecraft/server/level/ServerLevel.java
+@@ -0,0 +0,0 @@ public class ServerLevel extends Level implements WorldGenLevel {
+         return !this.server.isUnderSpawnProtection(this, pos, player) && this.getWorldBorder().isWithinBounds(pos);
+     }
+ 
++    // Paper start - Incremental chunk and player saving
++    public void saveIncrementally(boolean doFull) {
++        ServerChunkCache chunkproviderserver = this.getChunkSource();
++
++        if (doFull) {
++            org.bukkit.Bukkit.getPluginManager().callEvent(new org.bukkit.event.world.WorldSaveEvent(getWorld()));
++        }
++
++        try (co.aikar.timings.Timing ignored = this.timings.worldSave.startTiming()) {
++            if (doFull) {
++                this.saveLevelData();
++            }
++
++            this.timings.worldSaveChunks.startTiming(); // Paper
++            if (!this.noSave()) chunkproviderserver.saveIncrementally();
++            this.timings.worldSaveChunks.stopTiming(); // Paper
++
++            // Copied from save()
++            // CraftBukkit start - moved from MinecraftServer.saveChunks
++            if (doFull) { // Paper
++                ServerLevel worldserver1 = this;
++
++                this.serverLevelData.setWorldBorder(worldserver1.getWorldBorder().createSettings());
++                this.serverLevelData.setCustomBossEvents(this.server.getCustomBossEvents().save());
++                this.convertable.saveDataTag(this.server.registryAccess(), this.serverLevelData, this.server.getPlayerList().getSingleplayerData());
++            }
++            // CraftBukkit end
++        }
++    }
++    // Paper end - Incremental chunk and player saving
++
+     public void save(@Nullable ProgressListener progressListener, boolean flush, boolean savingDisabled) {
+         // Paper start - rewrite chunk system - add close param
+         this.save(progressListener, flush, savingDisabled, false);
+diff --git a/src/main/java/net/minecraft/server/level/ServerPlayer.java b/src/main/java/net/minecraft/server/level/ServerPlayer.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/server/level/ServerPlayer.java
++++ b/src/main/java/net/minecraft/server/level/ServerPlayer.java
+@@ -0,0 +0,0 @@ import org.bukkit.inventory.MainHand;
+ public class ServerPlayer extends Player {
+ 
+     private static final Logger LOGGER = LogUtils.getLogger();
++    public long lastSave = MinecraftServer.currentTick; // Paper - Incremental chunk and player saving
+     private static final int NEUTRAL_MOB_DEATH_NOTIFICATION_RADII_XZ = 32;
+     private static final int NEUTRAL_MOB_DEATH_NOTIFICATION_RADII_Y = 10;
+     private static final int FLY_STAT_RECORDING_SPEED = 25;
+diff --git a/src/main/java/net/minecraft/server/players/PlayerList.java b/src/main/java/net/minecraft/server/players/PlayerList.java
+index 0000000000000000000000000000000000000000..0000000000000000000000000000000000000000 100644
+--- a/src/main/java/net/minecraft/server/players/PlayerList.java
++++ b/src/main/java/net/minecraft/server/players/PlayerList.java
+@@ -0,0 +0,0 @@ public abstract class PlayerList {
+ 
+     protected void save(ServerPlayer player) {
+         if (!player.getBukkitEntity().isPersistent()) return; // CraftBukkit
++        player.lastSave = MinecraftServer.currentTick; // Paper - Incremental chunk and player saving
+         this.playerIo.save(player);
+         ServerStatsCounter serverstatisticmanager = (ServerStatsCounter) player.getStats(); // CraftBukkit
+ 
+@@ -0,0 +0,0 @@ public abstract class PlayerList {
+     }
+ 
+     public void saveAll() {
++        // Paper start - Incremental chunk and player saving
++        this.saveAll(-1);
++    }
++
++    public void saveAll(int interval) {
+         io.papermc.paper.util.MCUtil.ensureMain("Save Players" , () -> { // Paper - Ensure main
+         MinecraftTimings.savePlayers.startTiming(); // Paper
++        int numSaved = 0;
++        long now = MinecraftServer.currentTick;
+         for (int i = 0; i < this.players.size(); ++i) {
+-            this.save(this.players.get(i));
++            ServerPlayer entityplayer = this.players.get(i);
++            if (interval == -1 || now - entityplayer.lastSave >= interval) {
++                this.save(entityplayer);
++                if (interval != -1 && ++numSaved >= io.papermc.paper.configuration.GlobalConfiguration.get().playerAutoSave.maxPerTick()) { break; }
++            }
++            // Paper end - Incremental chunk and player saving
+         }
+         MinecraftTimings.savePlayers.stopTiming(); // Paper
+         return null; }); // Paper - ensure main