From 0db44545cdcd691b3104c4fa6fe87901bfdce15c Mon Sep 17 00:00:00 2001
From: TheMode <themode@outlook.fr>
Date: Fri, 13 Aug 2021 03:25:11 +0200
Subject: [PATCH] Do not copy collections unless necessary

---
 .../java/net/minestom/server/item/ItemMeta.java   | 15 +++++++++------
 .../net/minestom/server/item/ItemMetaBuilder.java | 10 +++++-----
 2 files changed, 14 insertions(+), 11 deletions(-)

diff --git a/src/main/java/net/minestom/server/item/ItemMeta.java b/src/main/java/net/minestom/server/item/ItemMeta.java
index 3e5d2ad55..19042eaf0 100644
--- a/src/main/java/net/minestom/server/item/ItemMeta.java
+++ b/src/main/java/net/minestom/server/item/ItemMeta.java
@@ -13,7 +13,10 @@ import org.jetbrains.annotations.Nullable;
 import org.jglrxavpok.hephaistos.nbt.NBTCompound;
 
 import java.nio.ByteBuffer;
-import java.util.*;
+import java.util.Collections;
+import java.util.List;
+import java.util.Map;
+import java.util.Set;
 import java.util.function.Consumer;
 
 public class ItemMeta implements TagReadable, Writeable {
@@ -43,12 +46,12 @@ public class ItemMeta implements TagReadable, Writeable {
         this.unbreakable = metaBuilder.unbreakable;
         this.hideFlag = metaBuilder.hideFlag;
         this.displayName = metaBuilder.displayName;
-        this.lore = new ArrayList<>(metaBuilder.lore);
-        this.enchantmentMap = new HashMap<>(metaBuilder.enchantmentMap);
-        this.attributes = new ArrayList<>(metaBuilder.attributes);
+        this.lore = List.copyOf(metaBuilder.lore);
+        this.enchantmentMap = Map.copyOf(metaBuilder.enchantmentMap);
+        this.attributes = List.copyOf(metaBuilder.attributes);
         this.customModelData = metaBuilder.customModelData;
-        this.canDestroy = new HashSet<>(metaBuilder.canDestroy);
-        this.canPlaceOn = new HashSet<>(metaBuilder.canPlaceOn);
+        this.canDestroy = Set.copyOf(metaBuilder.canDestroy);
+        this.canPlaceOn = Set.copyOf(metaBuilder.canPlaceOn);
 
         this.metaBuilder = metaBuilder;
         this.nbt = metaBuilder.nbt();
diff --git a/src/main/java/net/minestom/server/item/ItemMetaBuilder.java b/src/main/java/net/minestom/server/item/ItemMetaBuilder.java
index d668448ce..35d7317af 100644
--- a/src/main/java/net/minestom/server/item/ItemMetaBuilder.java
+++ b/src/main/java/net/minestom/server/item/ItemMetaBuilder.java
@@ -83,7 +83,7 @@ public abstract class ItemMetaBuilder implements TagWritable {
 
     @Contract("_ -> this")
     public @NotNull ItemMetaBuilder lore(@NotNull List<@NotNull Component> lore) {
-        this.lore = new ArrayList<>(lore);
+        this.lore = List.copyOf(lore);
         handleCompound("display", nbtCompound -> {
             final NBTList<NBTString> loreNBT = new NBTList<>(NBTTypes.TAG_String);
             for (Component line : lore) {
@@ -102,7 +102,7 @@ public abstract class ItemMetaBuilder implements TagWritable {
 
     @Contract("_ -> this")
     public @NotNull ItemMetaBuilder enchantments(@NotNull Map<Enchantment, Short> enchantments) {
-        this.enchantmentMap = new HashMap<>(enchantments);
+        this.enchantmentMap = Map.copyOf(enchantments);
         handleMap(enchantmentMap, "Enchantments", () -> {
             NBTUtils.writeEnchant(nbt, "Enchantments", enchantmentMap);
             return nbt.get("Enchantments");
@@ -126,7 +126,7 @@ public abstract class ItemMetaBuilder implements TagWritable {
 
     @Contract("_ -> this")
     public @NotNull ItemMetaBuilder attributes(@NotNull List<@NotNull ItemAttribute> attributes) {
-        this.attributes = new ArrayList<>(attributes);
+        this.attributes = List.copyOf(attributes);
 
         handleCollection(attributes, "AttributeModifiers", () -> {
             NBTList<NBTCompound> attributesNBT = new NBTList<>(NBTTypes.TAG_Compound);
@@ -157,7 +157,7 @@ public abstract class ItemMetaBuilder implements TagWritable {
 
     @Contract("_ -> this")
     public @NotNull ItemMetaBuilder canPlaceOn(@NotNull Set<@NotNull Block> blocks) {
-        this.canPlaceOn = new HashSet<>(blocks);
+        this.canPlaceOn = Set.copyOf(blocks);
         handleCollection(canPlaceOn, "CanPlaceOn", () -> {
             NBTList<NBTString> list = new NBTList<>(NBTTypes.TAG_String);
             canPlaceOn.forEach(block -> list.add(new NBTString(block.name())));
@@ -173,7 +173,7 @@ public abstract class ItemMetaBuilder implements TagWritable {
 
     @Contract("_ -> this")
     public @NotNull ItemMetaBuilder canDestroy(@NotNull Set<@NotNull Block> blocks) {
-        this.canDestroy = new HashSet<>(blocks);
+        this.canDestroy = Set.copyOf(blocks);
         handleCollection(canDestroy, "CanDestroy", () -> {
             NBTList<NBTString> list = new NBTList<>(NBTTypes.TAG_String);
             canDestroy.forEach(block -> list.add(new NBTString(block.name())));