From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Dreeam <61569423+Dreeam-qwq@users.noreply.github.com>
Date: Mon, 11 Nov 2024 02:46:39 -0500
Subject: [PATCH] Use faster and thread-safe ban list date format parsing

Use DateTimeFormatter since the original java SimpleDateFormat is not thread-safe
If store StoredUserList asynchronously, one data format may pollute another

Some performance test only for reference
Single thread, 10,000,000 times loop, java 21 (graalvm / zulu)

SimpleDateFormat:                       ~29,446ms
DateTimeFormatter:                      ~13,128ms
apache commons-lang's FastDateFormat:   ~23,514ms

diff --git a/src/main/java/net/minecraft/server/players/BanListEntry.java b/src/main/java/net/minecraft/server/players/BanListEntry.java
index 8b1da1fb5ca27432a39aff6dbc452b793268dab5..46188a8b8598c36ccb0f5e037a80eb1741c68491 100644
--- a/src/main/java/net/minecraft/server/players/BanListEntry.java
+++ b/src/main/java/net/minecraft/server/players/BanListEntry.java
@@ -10,7 +10,9 @@ import net.minecraft.network.chat.Component;
 
 public abstract class BanListEntry<T> extends StoredUserEntry<T> {
 
-    public static final SimpleDateFormat DATE_FORMAT = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss Z", Locale.ROOT);
+    //public static final SimpleDateFormat DATE_FORMAT = new SimpleDateFormat("yyyy-MM-dd HH:mm:ss Z", Locale.ROOT); // Leaf - I assume no one will use this, if yes, why?
+    private static final java.time.ZoneId ZONE_ID = java.time.ZoneId.systemDefault();
+    public static final java.time.format.DateTimeFormatter DATE_TIME_FORMATTER = java.time.format.DateTimeFormatter.ofPattern("yyyy-MM-dd HH:mm:ss Z"); // Leaf - Use faster and thread-safe ban list date format parsing
     public static final String EXPIRES_NEVER = "forever";
     protected final Date created;
     protected final String source;
@@ -32,8 +34,10 @@ public abstract class BanListEntry<T> extends StoredUserEntry<T> {
         Date date;
 
         try {
-            date = json.has("created") ? BanListEntry.DATE_FORMAT.parse(json.get("created").getAsString()) : new Date();
-        } catch (ParseException parseexception) {
+            // Leaf start - Use faster and thread-safe ban list date format parsing
+            date = json.has("created") ? parseToDate(json.get("created").getAsString()) : new Date();
+        } catch (java.time.format.DateTimeParseException e) {
+            // Leaf end - Use faster and thread-safe ban list date format parsing
             date = new Date();
         }
 
@@ -43,8 +47,10 @@ public abstract class BanListEntry<T> extends StoredUserEntry<T> {
         Date date1;
 
         try {
-            date1 = json.has("expires") ? BanListEntry.DATE_FORMAT.parse(json.get("expires").getAsString()) : null;
-        } catch (ParseException parseexception1) {
+            // Leaf start - Use faster and thread-safe ban list date format parsing
+            date1 = json.has("expires") ? parseToDate(json.get("expires").getAsString()) : null;
+        } catch (java.time.format.DateTimeParseException e) {
+            // Leaf end - Use faster and thread-safe ban list date format parsing
             date1 = null;
         }
 
@@ -78,9 +84,9 @@ public abstract class BanListEntry<T> extends StoredUserEntry<T> {
 
     @Override
     protected void serialize(JsonObject json) {
-        json.addProperty("created", BanListEntry.DATE_FORMAT.format(this.created));
+        json.addProperty("created", formateToString(this.created)); // Leaf - Use faster and thread-safe ban list date format parsing
         json.addProperty("source", this.source);
-        json.addProperty("expires", this.expires == null ? "forever" : BanListEntry.DATE_FORMAT.format(this.expires));
+        json.addProperty("expires", this.expires == null ? "forever" : formateToString(this.expires)); // Leaf - Use faster and thread-safe ban list date format parsing
         json.addProperty("reason", this.reason);
     }
 
@@ -89,9 +95,11 @@ public abstract class BanListEntry<T> extends StoredUserEntry<T> {
         Date expires = null;
 
         try {
-            expires = jsonobject.has("expires") ? BanListEntry.DATE_FORMAT.parse(jsonobject.get("expires").getAsString()) : null;
-        } catch (ParseException ex) {
+            // Leaf start - Use faster and thread-safe ban list date format parsing
+            expires = jsonobject.has("expires") ? parseToDate(jsonobject.get("expires").getAsString()) : null;
+        } catch (java.time.format.DateTimeParseException ignored) {
             // Guess we don't have a date
+            // Leaf end - Use faster and thread-safe ban list date format parsing
         }
 
         if (expires == null || expires.after(new Date())) {
@@ -101,4 +109,15 @@ public abstract class BanListEntry<T> extends StoredUserEntry<T> {
         }
     }
     // CraftBukkit end
+
+    // Leaf start - Use faster and thread-safe ban list date format parsing
+    public static Date parseToDate(String string) {
+        java.time.ZonedDateTime parsedDateTime = java.time.ZonedDateTime.parse(string, DATE_TIME_FORMATTER);
+        return Date.from(parsedDateTime.toInstant());
+    }
+
+    public static String formateToString(Date date) {
+        return DATE_TIME_FORMATTER.format(date.toInstant().atZone(ZONE_ID));
+    }
+    // Leaf end - Use faster and thread-safe ban list date format parsing
 }
diff --git a/src/main/java/net/minecraft/server/players/OldUsersConverter.java b/src/main/java/net/minecraft/server/players/OldUsersConverter.java
index 653856d0b8dcf2baf4cc77a276f17c8cc1fa717e..6416bc12f3d7733a4bd89d208a320f1b68983788 100644
--- a/src/main/java/net/minecraft/server/players/OldUsersConverter.java
+++ b/src/main/java/net/minecraft/server/players/OldUsersConverter.java
@@ -516,8 +516,10 @@ public class OldUsersConverter {
         Date date1;
 
         try {
-            date1 = BanListEntry.DATE_FORMAT.parse(dateString);
-        } catch (ParseException parseexception) {
+            // Leaf start - Use faster and thread-safe ban list date format parsing
+            date1 = BanListEntry.parseToDate(dateString);
+        } catch (java.time.format.DateTimeParseException e) {
+            // Leaf end - Use faster and thread-safe ban list date format parsing
             date1 = fallback;
         }