papermc/Spigot-Server-Patches/0389-Avoid-hopper-searches-if-there-are-no-items.patch
Aikar 210a32f26f
Unload leaked Cached Chunks
Due to some complexity in mojangs complicated chain of juggling
whether or not a chunk should be unloaded when the last ticket is
removed, many chunks are remaining around in the cache.

These chunks are never being targetted for unload because they are
vastly out of view distance range and have no reason to be looked at.

This is a huge issue for performance because we have to iterate these
chunks EVERY TICK... This is what's been leading to high SELF time in
Ticking Chunks timings/profiler results.

We will now detect these chunks in that iteration, and automatically
add it to the unload queue when the chunk is found without any tickets.
2020-05-25 11:12:22 -04:00

113 lines
5.7 KiB
Diff

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: CullanP <cullanpage@gmail.com>
Date: Thu, 3 Mar 2016 02:13:38 -0600
Subject: [PATCH] Avoid hopper searches if there are no items
Hoppers searching for items and minecarts is the most expensive part of hopper ticking.
We keep track of the number of minecarts and items in a chunk.
If there are no items in the chunk, we skip searching for items.
If there are no minecarts in the chunk, we skip searching for them.
Usually hoppers aren't near items, so we can skip most item searches.
And since minecart hoppers are used _very_ rarely near we can avoid alot of searching there.
Combined, this adds up a lot.
diff --git a/src/main/java/net/minecraft/server/Chunk.java b/src/main/java/net/minecraft/server/Chunk.java
index b855589d978d06e9883daff97c9e702d5a9461cc..9f0758aff6588736d500b6e202fc1a5f6a577e7f 100644
--- a/src/main/java/net/minecraft/server/Chunk.java
+++ b/src/main/java/net/minecraft/server/Chunk.java
@@ -84,6 +84,10 @@ public class Chunk implements IChunkAccess {
return removed;
}
}
+ // Track the number of minecarts and items
+ // Keep this synced with entitySlices.add() and entitySlices.remove()
+ private final int[] itemCounts = new int[16];
+ private final int[] inventoryEntityCounts = new int[16];
// Paper end
public Chunk(World world, ChunkCoordIntPair chunkcoordintpair, BiomeStorage biomestorage, ChunkConverter chunkconverter, TickList<Block> ticklist, TickList<FluidType> ticklist1, long i, @Nullable ChunkSection[] achunksection, @Nullable Consumer<Chunk> consumer) {
@@ -535,6 +539,13 @@ public class Chunk implements IChunkAccess {
entity.chunkZ = this.loc.z;
this.entities.add(entity); // Paper - per chunk entity list
this.entitySlices[k].add(entity);
+ // Paper start
+ if (entity instanceof EntityItem) {
+ itemCounts[k]++;
+ } else if (entity instanceof IInventory) {
+ inventoryEntityCounts[k]++;
+ }
+ // Paper end
entity.entitySlice = this.entitySlices[k]; // Paper
this.markDirty(); // Paper
}
@@ -567,6 +578,11 @@ public class Chunk implements IChunkAccess {
if (!this.entitySlices[i].remove(entity)) {
return;
}
+ if (entity instanceof EntityItem) {
+ itemCounts[i]--;
+ } else if (entity instanceof IInventory) {
+ inventoryEntityCounts[i]--;
+ }
entityCounts.decrement(entity.getMinecraftKeyString());
this.markDirty(); // Paper
// Paper end
@@ -850,6 +866,14 @@ public class Chunk implements IChunkAccess {
for (int k = i; k <= j; ++k) {
Iterator iterator = this.entitySlices[k].iterator(); // Spigot
+ // Paper start - Don't search for inventories if we have none, and that is all we want
+ /*
+ * We check if they want inventories by seeing if it is the static `IEntitySelector.d`
+ *
+ * Make sure the inventory selector stays in sync.
+ * It should be the one that checks `var1 instanceof IInventory && var1.isAlive()`
+ */
+ if (predicate == IEntitySelector.isInventory() && inventoryEntityCounts[k] <= 0) continue;
while (iterator.hasNext()) {
T entity = (T) iterator.next(); // CraftBukkit - decompile error
if (entity.shouldBeRemoved) continue; // Paper
@@ -869,9 +893,29 @@ public class Chunk implements IChunkAccess {
i = MathHelper.clamp(i, 0, this.entitySlices.length - 1);
j = MathHelper.clamp(j, 0, this.entitySlices.length - 1);
+ // Paper start
+ int[] counts;
+ if (EntityItem.class.isAssignableFrom(oclass)) {
+ counts = itemCounts;
+ } else if (IInventory.class.isAssignableFrom(oclass)) {
+ counts = inventoryEntityCounts;
+ } else {
+ counts = null;
+ }
+ // Paper end
for (int k = i; k <= j; ++k) {
+ if (counts != null && counts[k] <= 0) continue; // Paper - Don't check a chunk if it doesn't have the type we are looking for
Iterator iterator = this.entitySlices[k].iterator(); // Spigot
+ // Paper start - Don't search for inventories if we have none, and that is all we want
+ /*
+ * We check if they want inventories by seeing if it is the static `IEntitySelector.d`
+ *
+ * Make sure the inventory selector stays in sync.
+ * It should be the one that checks `var1 instanceof IInventory && var1.isAlive()`
+ */
+ if (predicate == IEntitySelector.isInventory() && inventoryEntityCounts[k] <= 0) continue;
+ // Paper end
while (iterator.hasNext()) {
T t0 = (T) iterator.next(); // CraftBukkit - decompile error
if (t0.shouldBeRemoved) continue; // Paper
diff --git a/src/main/java/net/minecraft/server/IEntitySelector.java b/src/main/java/net/minecraft/server/IEntitySelector.java
index 498f381099b2cf9460104688e12afc5f586e057a..a2d1ef3602a1c63d106d10140e18dfdb1d490805 100644
--- a/src/main/java/net/minecraft/server/IEntitySelector.java
+++ b/src/main/java/net/minecraft/server/IEntitySelector.java
@@ -11,6 +11,7 @@ public final class IEntitySelector {
public static final Predicate<Entity> c = (entity) -> {
return entity.isAlive() && !entity.isVehicle() && !entity.isPassenger();
};
+ public static final Predicate<Entity> isInventory() { return d; } // Paper - OBFHELPER
public static final Predicate<Entity> d = (entity) -> {
return entity instanceof IInventory && entity.isAlive();
};