1 files changed, 129 insertions, 0 deletions
diff --git a/patches/server/1027-Lag-compensation-ticks.patch b/patches/server/1027-Lag-compensation-ticks.patch
new file mode 100644
index 0000000000..fb9ab1a352
--- /dev/null
+++ b/patches/server/1027-Lag-compensation-ticks.patch
@@ -0,0 +1,129 @@
+From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
+From: Spottedleaf <[email protected]>
+Date: Sat, 23 Sep 2023 22:05:35 -0700
+Subject: [PATCH] Lag compensation ticks
+
+Areas affected by lag comepnsation:
+ - Block breaking and destroying
+ - Eating food items
+
+diff --git a/src/main/java/net/minecraft/server/MinecraftServer.java b/src/main/java/net/minecraft/server/MinecraftServer.java
+index b21daeeb043df885fba5e6a7572d311fd0830815..8515cec5e21ad291ca427baaafb4c2f337f01208 100644
+--- a/src/main/java/net/minecraft/server/MinecraftServer.java
++++ b/src/main/java/net/minecraft/server/MinecraftServer.java
+@@ -318,6 +318,7 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
+ 
+     public volatile Thread shutdownThread; // Paper
+     public volatile boolean abnormalExit = false; // Paper
++    public static final long SERVER_INIT = System.nanoTime(); // Paper - Lag compensation
+ 
+     public static <S extends MinecraftServer> S spin(Function<Thread, S> serverFactory) {
+         AtomicReference<S> atomicreference = new AtomicReference();
+@@ -1757,6 +1758,7 @@ public abstract class MinecraftServer extends ReentrantBlockableEventLoop<TickTa
+             worldserver.hasPhysicsEvent = org.bukkit.event.block.BlockPhysicsEvent.getHandlerList().getRegisteredListeners().length > 0; // Paper - BlockPhysicsEvent
+             worldserver.hasEntityMoveEvent = io.papermc.paper.event.entity.EntityMoveEvent.getHandlerList().getRegisteredListeners().length > 0; // Paper - Add EntityMoveEvent
+             net.minecraft.world.level.block.entity.HopperBlockEntity.skipHopperEvents = worldserver.paperConfig().hopper.disableMoveEvent || org.bukkit.event.inventory.InventoryMoveItemEvent.getHandlerList().getRegisteredListeners().length == 0; // Paper - Perf: Optimize Hoppers
++            worldserver.updateLagCompensationTick(); // Paper - lag compensation
+ 
+             this.profiler.push(() -> {
+                 String s = String.valueOf(worldserver);
+diff --git a/src/main/java/net/minecraft/server/level/ServerLevel.java b/src/main/java/net/minecraft/server/level/ServerLevel.java
+index 232ee4e3f32b93f5ae725b025abd538fe8927d90..05e7a908c18b5eef49afb088b7519185bc806056 100644
+--- a/src/main/java/net/minecraft/server/level/ServerLevel.java
++++ b/src/main/java/net/minecraft/server/level/ServerLevel.java
+@@ -570,6 +570,17 @@ public class ServerLevel extends Level implements WorldGenLevel {
+         return player != null && player.level() == this ? player : null;
+     }
+     // Paper end - optimise getPlayerByUUID
++    // Paper start - lag compensation
++    private long lagCompensationTick = net.minecraft.server.MinecraftServer.SERVER_INIT;
++
++    public long getLagCompensationTick() {
++        return this.lagCompensationTick;
++    }
++
++    public void updateLagCompensationTick() {
++        this.lagCompensationTick = (System.nanoTime() - net.minecraft.server.MinecraftServer.SERVER_INIT) / (java.util.concurrent.TimeUnit.MILLISECONDS.toNanos(50L));
++    }
++    // Paper end - lag compensation
+ 
+     // Add env and gen to constructor, IWorldDataServer -> WorldDataServer
+     public ServerLevel(MinecraftServer minecraftserver, Executor executor, LevelStorageSource.LevelStorageAccess convertable_conversionsession, PrimaryLevelData iworlddataserver, ResourceKey<Level> resourcekey, LevelStem worlddimension, ChunkProgressListener worldloadlistener, boolean flag, long i, List<CustomSpawner> list, boolean flag1, @Nullable RandomSequences randomsequences, org.bukkit.World.Environment env, org.bukkit.generator.ChunkGenerator gen, org.bukkit.generator.BiomeProvider biomeProvider) {
+diff --git a/src/main/java/net/minecraft/server/level/ServerPlayerGameMode.java b/src/main/java/net/minecraft/server/level/ServerPlayerGameMode.java
+index f168044d36f22080504da171e5ed31a6f02385ba..5cedce1f432f6b809b25269242a16477682c824f 100644
+--- a/src/main/java/net/minecraft/server/level/ServerPlayerGameMode.java
++++ b/src/main/java/net/minecraft/server/level/ServerPlayerGameMode.java
+@@ -127,7 +127,7 @@ public class ServerPlayerGameMode {
+     }
+ 
+     public void tick() {
+-        this.gameTicks = MinecraftServer.currentTick; // CraftBukkit;
++        this.gameTicks = (int)this.level.getLagCompensationTick(); // CraftBukkit; // Paper - lag compensation
+         BlockState iblockdata;
+ 
+         if (this.hasDelayedDestroy) {
+diff --git a/src/main/java/net/minecraft/world/entity/LivingEntity.java b/src/main/java/net/minecraft/world/entity/LivingEntity.java
+index 2d375fc98e72246f6a640c390cb50d055fb59f8b..bad6a69246f6b0a4ada222b820f16469f91b0534 100644
+--- a/src/main/java/net/minecraft/world/entity/LivingEntity.java
++++ b/src/main/java/net/minecraft/world/entity/LivingEntity.java
+@@ -3833,6 +3833,10 @@ public abstract class LivingEntity extends Entity implements Attackable {
+         this.resendPossiblyDesyncedDataValues(java.util.List.of(DATA_LIVING_ENTITY_FLAGS), serverPlayer);
+     }
+     // Paper end - Properly cancel usable items
++    // Paper start - lag compensate eating
++    protected long eatStartTime;
++    protected int totalEatTimeTicks;
++    // Paper end - lag compensate eating
+     private void updatingUsingItem() {
+         if (this.isUsingItem()) {
+             if (ItemStack.isSameItem(this.getItemInHand(this.getUsedItemHand()), this.useItem)) {
+@@ -3851,7 +3855,12 @@ public abstract class LivingEntity extends Entity implements Attackable {
+             this.triggerItemUseEffects(stack, 5);
+         }
+ 
+-        if (--this.useItemRemaining == 0 && !this.level().isClientSide && !stack.useOnRelease()) {
++        // Paper start - lag compensate eating
++        // we add 1 to the expected time to avoid lag compensating when we should not
++        boolean shouldLagCompensate = this.useItem.getItem().components().has(DataComponents.FOOD) && this.eatStartTime != -1 && (System.nanoTime() - this.eatStartTime) > ((1 + this.totalEatTimeTicks) * 50 * (1000 * 1000));
++        if ((--this.useItemRemaining == 0 || shouldLagCompensate) && !this.level().isClientSide && !stack.useOnRelease()) {
++            this.useItemRemaining = 0;
++            // Paper end - lag compensate eating
+             this.completeUsingItem();
+         }
+ 
+@@ -3897,7 +3906,10 @@ public abstract class LivingEntity extends Entity implements Attackable {
+ 
+         if (!itemstack.isEmpty() && !this.isUsingItem() || forceUpdate) { // Paper - Prevent consuming the wrong itemstack
+             this.useItem = itemstack;
+-            this.useItemRemaining = itemstack.getUseDuration();
++            // Paper start - lag compensate eating
++            this.useItemRemaining = this.totalEatTimeTicks = itemstack.getUseDuration();
++            this.eatStartTime = System.nanoTime();
++            // Paper end - lag compensate eating
+             if (!this.level().isClientSide) {
+                 this.setLivingEntityFlag(1, true);
+                 this.setLivingEntityFlag(2, hand == InteractionHand.OFF_HAND);
+@@ -3922,7 +3934,10 @@ public abstract class LivingEntity extends Entity implements Attackable {
+                 }
+             } else if (!this.isUsingItem() && !this.useItem.isEmpty()) {
+                 this.useItem = ItemStack.EMPTY;
+-                this.useItemRemaining = 0;
++                // Paper start - lag compensate eating
++                this.useItemRemaining = this.totalEatTimeTicks = 0;
++                this.eatStartTime = -1L;
++                // Paper end - lag compensate eating
+             }
+         }
+ 
+@@ -4057,7 +4072,10 @@ public abstract class LivingEntity extends Entity implements Attackable {
+         }
+ 
+         this.useItem = ItemStack.EMPTY;
+-        this.useItemRemaining = 0;
++        // Paper start - lag compensate eating
++        this.useItemRemaining = this.totalEatTimeTicks = 0;
++        this.eatStartTime = -1L;
++        // Paper end - lag compensate eating
+     }
+ 
+     public boolean isBlocking() {