Use Last Access Cache for isLoaded calls

this should provide a pretty good across-the-board performance
improvement for the entire server, as it's very common for code
to check if (isLoaded(x, z)) { then do something on that chunk }

Previously, containsKey would not read or set the last access cache

By making it do get() != null, we gain the benefits of last access
and also improves thread safey for async isLoaded checks

This exact usage scenario is used in Entity movement, so that alone
saves us up to 5%~ of CPU time for Entity movement.
This commit is contained in:
Aikar 2018-10-23 23:50:51 -04:00
parent e9305f96a3
commit d07f7197f2
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@ -1,4 +1,4 @@
From eb8942dae2dd6dbc8a32b05c0a502a4a507d7233 Mon Sep 17 00:00:00 2001
From 7ac07ac07ac07ac07ac07ac07ac07ac07ac07ac0 Mon Sep 17 00:00:00 2001
From: Aikar <aikar@aikar.co>
Date: Thu, 27 Aug 2015 01:15:02 -0400
Subject: [PATCH] Optimize Chunk Access
@ -9,7 +9,7 @@ getChunkAt is called for the same chunk multiple times in a row, often from getT
Optimize this look up by using a Last Access cache.
diff --git a/src/main/java/net/minecraft/server/ChunkMap.java b/src/main/java/net/minecraft/server/ChunkMap.java
index 4b8b77710b..71ddaf591e 100644
index 7ac07ac07ac0..7ac07ac07ac0 100644
--- a/src/main/java/net/minecraft/server/ChunkMap.java
+++ b/src/main/java/net/minecraft/server/ChunkMap.java
@@ -15,6 +15,7 @@ public class ChunkMap extends Long2ObjectOpenHashMap<Chunk> {
@ -71,7 +71,7 @@ index 4b8b77710b..71ddaf591e 100644
public Chunk a(Object object) {
return this.a(((Long) object).longValue());
diff --git a/src/main/java/net/minecraft/server/ChunkProviderServer.java b/src/main/java/net/minecraft/server/ChunkProviderServer.java
index d16fc452e3..2d10f4aa37 100644
index 7ac07ac07ac0..7ac07ac07ac0 100644
--- a/src/main/java/net/minecraft/server/ChunkProviderServer.java
+++ b/src/main/java/net/minecraft/server/ChunkProviderServer.java
@@ -78,15 +78,16 @@ public class ChunkProviderServer implements IChunkProvider {
@ -112,6 +112,14 @@ index d16fc452e3..2d10f4aa37 100644
}
return true;
}
@@ -379,6 +380,6 @@ public class ChunkProviderServer implements IChunkProvider {
}
public boolean isLoaded(int i, int j) {
- return this.chunks.containsKey(ChunkCoordIntPair.a(i, j));
+ return this.chunks.get(ChunkCoordIntPair.asLong(i, j)) != null; // Paper - use get for last access
}
}
--
2.19.1