Optimize the advancement data player iteration to be O(N) rather than O(N^2)

This commit is contained in:
Wyatt Childers 2020-07-04 23:08:23 -04:00 committed by Aikar
parent c2c4cf44b6
commit 97cedaa589
No known key found for this signature in database
GPG key ID: 401ADFC9891FAAFE

View file

@ -0,0 +1,54 @@
From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Wyatt Childers <wchilders@nearce.com>
Date: Sat, 4 Jul 2020 23:07:43 -0400
Subject: [PATCH] Optimize the advancement data player iteration to be O(N)
rather than O(N^2)
diff --git a/src/main/java/net/minecraft/server/AdvancementDataPlayer.java b/src/main/java/net/minecraft/server/AdvancementDataPlayer.java
index 57b9d13447a4f7804827c1bd41121c3069c696bd..d3387a4e16f81b820d40502d2c46ebb3db88f824 100644
--- a/src/main/java/net/minecraft/server/AdvancementDataPlayer.java
+++ b/src/main/java/net/minecraft/server/AdvancementDataPlayer.java
@@ -439,6 +439,16 @@ public class AdvancementDataPlayer {
}
private void e(Advancement advancement) {
+ // Paper start
+ e(advancement, IterationEntryPoint.ROOT);
+ }
+ private enum IterationEntryPoint {
+ ROOT,
+ ITERATOR,
+ PARENT_OF_ITERATOR
+ }
+ private void e(Advancement advancement, IterationEntryPoint entryPoint) {
+ // Paper end
boolean flag = this.f(advancement);
boolean flag1 = this.h.contains(advancement);
@@ -454,15 +464,23 @@ public class AdvancementDataPlayer {
}
if (flag != flag1 && advancement.b() != null) {
- this.e(advancement.b());
+ // Paper start - If we're not coming from an iterator consider this to be a root entry, otherwise
+ // market that we're entering from the parent of an iterator.
+ this.e(advancement.b(), entryPoint == IterationEntryPoint.ITERATOR ? IterationEntryPoint.PARENT_OF_ITERATOR : IterationEntryPoint.ROOT);
}
+ // If this is true, we've went through a child iteration, entered the parent, processed the parent
+ // and are about to reprocess the children. Stop processing here to prevent O(N^2) processing.
+ if (entryPoint == IterationEntryPoint.PARENT_OF_ITERATOR) {
+ return;
+ } // Paper end
+
Iterator iterator = advancement.e().iterator();
while (iterator.hasNext()) {
Advancement advancement1 = (Advancement) iterator.next();
- this.e(advancement1);
+ this.e(advancement1, IterationEntryPoint.ITERATOR); // Paper - Mark this call as being from iteration
}
}