PaperMC/Spigot-API-Patches/0078-PreCreatureSpawnEvent.patch
Spottedleaf 5c7081fecc Update upstream & fix some chunk related issues (#2177)
* Updated Upstream (Bukkit/CraftBukkit)

Upstream has released updates that appears to apply and compile correctly.
This update has not been tested by PaperMC and as with ANY update, please do your own testing

Bukkit Changes:
45690fe9 SPIGOT-5047: Correct slot types for 1.14 inventories

CraftBukkit Changes:
4090d01f SPIGOT-5047: Correct slot types for 1.14 inventories
e8c08362 SPIGOT-5046: World#getLoadedChunks returning inaccessible cached chunks.
d445af3b SPIGOT-5067: Add item meta for 1.14 spawn eggs

* Bring Chunk load checks in-line with spigot

As of the last upstream merge spigot now checks ticket level status
when returning loaded chunks for a world from api. Now our checks
will respect that decision.

* Fix spawn ticket levels

Vanilla would keep the inner chunks of spawn available for ticking,
however my changes made all chunks non-ticking. Resolve by changing
ticket levels for spawn chunks inside the border to respect this
behavior.


* Make World#getChunkIfLoadedImmediately return only entity ticking chunks

Mojang appears to be using chunks with level > 33 (non-ticking chunks)
as cached chunks and not actually loaded chunks.

* Bring all loaded checks in line with spigot

Loaded chunks must be at least border  chunks, or level <= 33
2019-06-14 03:27:40 +01:00

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Diff

From f964e9674f741b077eb95edddad85d9faf01e638 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Sun, 14 Jan 2018 16:59:43 -0500
Subject: [PATCH] PreCreatureSpawnEvent
Adds an event to fire before an Entity is created, so that plugins that need to cancel
CreatureSpawnEvent can do so from this event instead.
Cancelling CreatureSpawnEvent rapidly causes a lot of garbage collection and CPU waste
as it's done after the Entity object has been fully created.
Mob Limiting plugins and blanket "ban this type of monster" plugins should use this event
instead and save a lot of server resources.
See: https://github.com/PaperMC/Paper/issues/917
diff --git a/src/main/java/com/destroystokyo/paper/event/entity/PreCreatureSpawnEvent.java b/src/main/java/com/destroystokyo/paper/event/entity/PreCreatureSpawnEvent.java
new file mode 100644
index 000000000..d5edde9cd
--- /dev/null
+++ b/src/main/java/com/destroystokyo/paper/event/entity/PreCreatureSpawnEvent.java
@@ -0,0 +1,104 @@
+package com.destroystokyo.paper.event.entity;
+
+import com.google.common.base.Preconditions;
+import org.bukkit.Location;
+import org.bukkit.entity.EntityType;
+import org.bukkit.event.Cancellable;
+import org.bukkit.event.Event;
+import org.bukkit.event.HandlerList;
+import org.bukkit.event.entity.CreatureSpawnEvent;
+import org.jetbrains.annotations.NotNull;
+
+/**
+ * WARNING: This event only fires for a limited number of cases, and not for every case that CreatureSpawnEvent does.
+ *
+ * You should still listen to CreatureSpawnEvent as a backup, and only use this event as an "enhancement".
+ * The intent of this event is to improve server performance, so limited use cases.
+ *
+ * Currently: NATURAL and SPAWNER based reasons. Please submit a Pull Request for future additions.
+ * Also, Plugins that replace Entity Registrations with their own custom entities might not fire this event.
+ */
+public class PreCreatureSpawnEvent extends Event implements Cancellable {
+ @NotNull private final Location location;
+ @NotNull private final EntityType type;
+ @NotNull private final CreatureSpawnEvent.SpawnReason reason;
+ private boolean shouldAbortSpawn;
+
+ public PreCreatureSpawnEvent(@NotNull Location location, @NotNull EntityType type, @NotNull CreatureSpawnEvent.SpawnReason reason) {
+ this.location = Preconditions.checkNotNull(location, "Location may not be null").clone();
+ this.type = Preconditions.checkNotNull(type, "Type may not be null");
+ this.reason = Preconditions.checkNotNull(reason, "Reason may not be null");
+ }
+
+ /**
+ * @return The location this creature is being spawned at
+ */
+ @NotNull
+ public Location getSpawnLocation() {
+ return location;
+ }
+
+ /**
+ * @return The type of creature being spawned
+ */
+ @NotNull
+ public EntityType getType() {
+ return type;
+ }
+
+ /**
+ * @return Reason this creature is spawning (ie, NATURAL vs SPAWNER)
+ */
+ @NotNull
+ public CreatureSpawnEvent.SpawnReason getReason() {
+ return reason;
+ }
+
+ /**
+ * @return If the spawn process should be aborted vs trying more attempts
+ */
+ public boolean shouldAbortSpawn() {
+ return shouldAbortSpawn;
+ }
+
+ /**
+ * Set this if you are more blanket blocking all types of these spawns, and wish to abort the spawn process from
+ * trying more attempts after this cancellation.
+ *
+ * @param shouldAbortSpawn Set if the spawn process should be aborted vs trying more attempts
+ */
+ public void setShouldAbortSpawn(boolean shouldAbortSpawn) {
+ this.shouldAbortSpawn = shouldAbortSpawn;
+ }
+
+ private static final HandlerList handlers = new HandlerList();
+
+ @NotNull
+ public HandlerList getHandlers() {
+ return handlers;
+ }
+
+ @NotNull
+ public static HandlerList getHandlerList() {
+ return handlers;
+ }
+
+ private boolean cancelled = false;
+
+ /**
+ * @return If the spawn of this creature is cancelled or not
+ */
+ @Override
+ public boolean isCancelled() {
+ return cancelled;
+ }
+
+ /**
+ * Cancelling this event is more effecient than cancelling CreatureSpawnEvent
+ * @param cancel true if you wish to cancel this event, and abort the spawn of this creature
+ */
+ @Override
+ public void setCancelled(boolean cancel) {
+ cancelled = cancel;
+ }
+}
--
2.21.0