Paper/src/main/java/net/minecraft/server/ChunkProviderServer.java
Travis Watkins 74b3be57b7 Replace LongObjectHashMap with a more efficient implementation
After further testing it appears that while the original LongHashtable
has issues with object creation churn and is severly slower than even
java.util.HashMap in general case benchmarks it is in fact very efficient
for our use case.

With this in mind I wrote a replacement LongObjectHashMap modeled after
LongHashtable. Unlike the original implementation this one does not use
Entry objects for storage so does not have the same object creation churn.
It also uses a 2D array instead of a 3D one and does not use a cache as
benchmarking shows this is more efficient. The "bucket size" was chosen
based on benchmarking performance of the HashMap with contents that would
be plausible for a 200+ player server. This means it uses a little extra
memory for smaller servers but almost always uses less than the normal
java.util.HashMap.

To make up for the original LongHashtable being a poor choice for generic
datasets I added a mixer to the new implementation based on code from
MurmurHash. While this has no noticable effect positive or negative with
our normal use of chunk coordinates it makes the HashMap perform just as
well with nearly any kind of dataset.

After these changes ChunkProviderServer.isChunkLoaded() goes from using
20% CPU time while sampling to not even showing up after 45 minutes of
sampling due to the CPU usage being too low to be noticed.
2012-09-21 11:20:10 -05:00

297 Zeilen
9.8 KiB
Java

package net.minecraft.server;
import java.io.IOException;
import java.util.ArrayList;
import java.util.HashSet;
import java.util.Iterator;
import java.util.List;
import java.util.Set;
// CraftBukkit start
import java.util.Random;
import org.bukkit.Server;
import org.bukkit.craftbukkit.util.LongHash;
import org.bukkit.craftbukkit.util.LongHashSet;
import org.bukkit.craftbukkit.util.LongObjectHashMap;
import org.bukkit.event.world.ChunkUnloadEvent;
// CraftBukkit end
public class ChunkProviderServer implements IChunkProvider {
// CraftBukkit start
public LongHashSet unloadQueue = new LongHashSet();
public Chunk emptyChunk;
public IChunkProvider chunkProvider; // CraftBukkit
private IChunkLoader e;
public boolean forceChunkLoad = false; // true -> false
public LongObjectHashMap<Chunk> chunks = new LongObjectHashMap<Chunk>();
public WorldServer world;
// CraftBukkit end
public ChunkProviderServer(WorldServer worldserver, IChunkLoader ichunkloader, IChunkProvider ichunkprovider) {
this.emptyChunk = new EmptyChunk(worldserver, 0, 0);
this.world = worldserver;
this.e = ichunkloader;
this.chunkProvider = ichunkprovider;
}
public boolean isChunkLoaded(int i, int j) {
return this.chunks.containsKey(LongHash.toLong(i, j)); // CraftBukkit
}
public void queueUnload(int i, int j) {
if (this.world.worldProvider.e()) {
ChunkCoordinates chunkcoordinates = this.world.getSpawn();
int k = i * 16 + 8 - chunkcoordinates.x;
int l = j * 16 + 8 - chunkcoordinates.z;
short short1 = 128;
// CraftBukkit start
if (k < -short1 || k > short1 || l < -short1 || l > short1 || !(this.world.keepSpawnInMemory)) { // Added 'this.world.keepSpawnInMemory'
this.unloadQueue.add(i, j);
Chunk c = this.chunks.get(LongHash.toLong(i, j));
if (c != null) {
c.mustSave = true;
}
}
// CraftBukkit end
} else {
// CraftBukkit start
this.unloadQueue.add(i, j);
Chunk c = this.chunks.get(LongHash.toLong(i, j));
if (c != null) {
c.mustSave = true;
}
// CraftBukkit end
}
}
public void a() {
Iterator iterator = this.chunks.values().iterator(); // CraftBukkit
while (iterator.hasNext()) {
Chunk chunk = (Chunk) iterator.next();
this.queueUnload(chunk.x, chunk.z);
}
}
public Chunk getChunkAt(int i, int j) {
// CraftBukkit start
this.unloadQueue.remove(i, j);
Chunk chunk = (Chunk) this.chunks.get(LongHash.toLong(i, j));
boolean newChunk = false;
// CraftBukkit end
if (chunk == null) {
chunk = this.loadChunk(i, j);
if (chunk == null) {
if (this.chunkProvider == null) {
chunk = this.emptyChunk;
} else {
chunk = this.chunkProvider.getOrCreateChunk(i, j);
}
newChunk = true; // CraftBukkit
}
this.chunks.put(LongHash.toLong(i, j), chunk); // CraftBukkit
if (chunk != null) {
chunk.addEntities();
}
// CraftBukkit start
Server server = this.world.getServer();
if (server != null) {
/*
* If it's a new world, the first few chunks are generated inside
* the World constructor. We can't reliably alter that, so we have
* no way of creating a CraftWorld/CraftServer at that point.
*/
server.getPluginManager().callEvent(new org.bukkit.event.world.ChunkLoadEvent(chunk.bukkitChunk, newChunk));
}
// CraftBukkit end
chunk.a(this, this, i, j);
}
return chunk;
}
public Chunk getOrCreateChunk(int i, int j) {
// CraftBukkit start
Chunk chunk = (Chunk) this.chunks.get(LongHash.toLong(i, j));
chunk = chunk == null ? (!this.world.isLoading && !this.forceChunkLoad ? this.emptyChunk : this.getChunkAt(i, j)) : chunk;
if (chunk == this.emptyChunk) return chunk;
if (i != chunk.x || j != chunk.z) {
MinecraftServer.log.severe("Chunk (" + chunk.x + ", " + chunk.z + ") stored at (" + i + ", " + j + ") in world '" + world.getWorld().getName() + "'");
MinecraftServer.log.severe(chunk.getClass().getName());
Throwable ex = new Throwable();
ex.fillInStackTrace();
ex.printStackTrace();
}
return chunk;
// CraftBukkit end
}
public Chunk loadChunk(int i, int j) { // CraftBukkit - private -> public
if (this.e == null) {
return null;
} else {
try {
Chunk chunk = this.e.a(this.world, i, j);
if (chunk != null) {
chunk.n = this.world.getTime();
}
return chunk;
} catch (Exception exception) {
exception.printStackTrace();
return null;
}
}
}
public void saveChunkNOP(Chunk chunk) { // CraftBukkit - private -> public
if (this.e != null) {
try {
this.e.b(this.world, chunk);
} catch (Exception exception) {
exception.printStackTrace();
}
}
}
public void saveChunk(Chunk chunk) { // CraftBukkit - private -> public
if (this.e != null) {
try {
chunk.n = this.world.getTime();
this.e.a(this.world, chunk);
} catch (Exception ioexception) { // CraftBukkit - IOException -> Exception
ioexception.printStackTrace();
// CraftBukkit start - remove extra exception
}
// } catch (ExceptionWorldConflict exceptionworldconflict) {
// exceptionworldconflict.printStackTrace();
// }
// CraftBukkit end
}
}
public void getChunkAt(IChunkProvider ichunkprovider, int i, int j) {
Chunk chunk = this.getOrCreateChunk(i, j);
if (!chunk.done) {
chunk.done = true;
if (this.chunkProvider != null) {
this.chunkProvider.getChunkAt(ichunkprovider, i, j);
// CraftBukkit start
BlockSand.instaFall = true;
Random random = new Random();
random.setSeed(world.getSeed());
long xRand = random.nextLong() / 2L * 2L + 1L;
long zRand = random.nextLong() / 2L * 2L + 1L;
random.setSeed((long) i * xRand + (long) j * zRand ^ world.getSeed());
org.bukkit.World world = this.world.getWorld();
if (world != null) {
for (org.bukkit.generator.BlockPopulator populator : world.getPopulators()) {
populator.populate(world, random, chunk.bukkitChunk);
}
}
BlockSand.instaFall = false;
this.world.getServer().getPluginManager().callEvent(new org.bukkit.event.world.ChunkPopulateEvent(chunk.bukkitChunk));
// CraftBukkit end
chunk.e();
}
}
}
public boolean saveChunks(boolean flag, IProgressUpdate iprogressupdate) {
int i = 0;
Iterator iterator = this.chunks.values().iterator(); // CraftBukkit
while (iterator.hasNext()) {
Chunk chunk = (Chunk) iterator.next();
if (flag) {
this.saveChunkNOP(chunk);
}
if (chunk.a(flag)) {
this.saveChunk(chunk);
chunk.l = false;
++i;
if (i == 24 && !flag) {
return false;
}
}
}
if (flag) {
if (this.e == null) {
return true;
}
this.e.b();
}
return true;
}
public boolean unloadChunks() {
if (!this.world.savingDisabled) {
// CraftBukkit start
Server server = this.world.getServer();
for (int i = 0; i < 50 && !this.unloadQueue.isEmpty(); i++) {
long chunkcoordinates = this.unloadQueue.popFirst();
Chunk chunk = this.chunks.get(chunkcoordinates);
if (chunk == null) continue;
ChunkUnloadEvent event = new ChunkUnloadEvent(chunk.bukkitChunk);
server.getPluginManager().callEvent(event);
if (!event.isCancelled()) {
chunk.removeEntities();
this.saveChunk(chunk);
this.saveChunkNOP(chunk);
// this.unloadQueue.remove(integer);
this.chunks.remove(chunkcoordinates); // CraftBukkit
}
}
// CraftBukkit end
if (this.e != null) {
this.e.a();
}
}
return this.chunkProvider.unloadChunks();
}
public boolean canSave() {
return !this.world.savingDisabled;
}
public String getName() {
return "ServerChunkCache: " + this.chunks.values().size() + " Drop: " + this.unloadQueue.size(); // CraftBukkit
}
public List getMobsFor(EnumCreatureType enumcreaturetype, int i, int j, int k) {
return this.chunkProvider.getMobsFor(enumcreaturetype, i, j, k);
}
public ChunkPosition findNearestMapFeature(World world, String s, int i, int j, int k) {
return this.chunkProvider.findNearestMapFeature(world, s, i, j, k);
}
public int getLoadedChunks() {
return this.chunks.values().size(); // CraftBukkit
}
}