Folia/patches/server/0006-Cache-whether-region-files-do-not-exist.patch
Spottedleaf b42537ed02 Cache whether region files do not exist
The repeated I/O of creating the directory for the regionfile
or for checking if the file exists can be heavy in
when pushing chunk generation extremely hard - as each chunk gen
request may effectively go through to the I/O thread.
2023-03-02 23:26:47 -08:00

120 lines
6.6 KiB
Diff

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Spottedleaf <Spottedleaf@users.noreply.github.com>
Date: Thu, 2 Mar 2023 23:19:04 -0800
Subject: [PATCH] Cache whether region files do not exist
The repeated I/O of creating the directory for the regionfile
or for checking if the file exists can be heavy in
when pushing chunk generation extremely hard - as each chunk gen
request may effectively go through to the I/O thread.
diff --git a/src/main/java/io/papermc/paper/chunk/system/io/RegionFileIOThread.java b/src/main/java/io/papermc/paper/chunk/system/io/RegionFileIOThread.java
index a08cde4eefe879adcee7c4118bc38f98c5097ed0..8a11e10b01fa012b2f98b1c193c53251e848f909 100644
--- a/src/main/java/io/papermc/paper/chunk/system/io/RegionFileIOThread.java
+++ b/src/main/java/io/papermc/paper/chunk/system/io/RegionFileIOThread.java
@@ -819,8 +819,14 @@ public final class RegionFileIOThread extends PrioritisedQueueExecutorThread {
return file.hasChunk(chunkPos) ? Boolean.TRUE : Boolean.FALSE;
});
} else {
+ // first check if the region file for sure does not exist
+ if (taskController.doesRegionFileNotExist(chunkX, chunkZ)) {
+ return Boolean.FALSE;
+ } // else: it either exists or is not known, fall back to checking the loaded region file
+
return taskController.computeForRegionFileIfLoaded(chunkX, chunkZ, (final RegionFile file) -> {
if (file == null) { // null if not loaded
+ // not sure at this point, let the I/O thread figure it out
return Boolean.TRUE;
}
@@ -1116,6 +1122,10 @@ public final class RegionFileIOThread extends PrioritisedQueueExecutorThread {
return !this.tasks.isEmpty();
}
+ public boolean doesRegionFileNotExist(final int chunkX, final int chunkZ) {
+ return this.getCache().doesRegionFileNotExistNoIO(new ChunkPos(chunkX, chunkZ));
+ }
+
public <T> T computeForRegionFile(final int chunkX, final int chunkZ, final boolean existingOnly, final Function<RegionFile, T> function) {
final RegionFileStorage cache = this.getCache();
final RegionFile regionFile;
diff --git a/src/main/java/net/minecraft/world/level/chunk/storage/RegionFileStorage.java b/src/main/java/net/minecraft/world/level/chunk/storage/RegionFileStorage.java
index bd502ca721de0cab438d995efa00ad0554c0d2fe..9633b01d2d961fd1403e353484d336376ef009eb 100644
--- a/src/main/java/net/minecraft/world/level/chunk/storage/RegionFileStorage.java
+++ b/src/main/java/net/minecraft/world/level/chunk/storage/RegionFileStorage.java
@@ -28,6 +28,35 @@ public class RegionFileStorage implements AutoCloseable {
private final boolean isChunkData; // Paper
+ // Paper start - cache regionfile does not exist state
+ static final int MAX_NON_EXISTING_CACHE = 1024 * 64;
+ private final it.unimi.dsi.fastutil.longs.LongLinkedOpenHashSet nonExistingRegionFiles = new it.unimi.dsi.fastutil.longs.LongLinkedOpenHashSet();
+ private synchronized boolean doesRegionFilePossiblyExist(long position) {
+ if (this.nonExistingRegionFiles.contains(position)) {
+ this.nonExistingRegionFiles.addAndMoveToFirst(position);
+ return false;
+ }
+ return true;
+ }
+
+ private synchronized void createRegionFile(long position) {
+ this.nonExistingRegionFiles.remove(position);
+ }
+
+ private synchronized void markNonExisting(long position) {
+ if (this.nonExistingRegionFiles.addAndMoveToFirst(position)) {
+ while (this.nonExistingRegionFiles.size() >= MAX_NON_EXISTING_CACHE) {
+ this.nonExistingRegionFiles.removeLastLong();
+ }
+ }
+ }
+
+ public synchronized boolean doesRegionFileNotExistNoIO(ChunkPos pos) {
+ long key = ChunkPos.asLong(pos.getRegionX(), pos.getRegionZ());
+ return !this.doesRegionFilePossiblyExist(key);
+ }
+ // Paper end - cache regionfile does not exist state
+
protected RegionFileStorage(Path directory, boolean dsync) { // Paper - protected constructor
// Paper start - add isChunkData param
this(directory, dsync, false);
@@ -77,7 +106,7 @@ public class RegionFileStorage implements AutoCloseable {
}
public synchronized RegionFile getRegionFile(ChunkPos chunkcoordintpair, boolean existingOnly, boolean lock) throws IOException {
// Paper end
- long i = ChunkPos.asLong(chunkcoordintpair.getRegionX(), chunkcoordintpair.getRegionZ());
+ long i = ChunkPos.asLong(chunkcoordintpair.getRegionX(), chunkcoordintpair.getRegionZ()); final long regionPos = i; // Paper - OBFHELPER
RegionFile regionfile = (RegionFile) this.regionCache.getAndMoveToFirst(i);
if (regionfile != null) {
@@ -89,15 +118,27 @@ public class RegionFileStorage implements AutoCloseable {
// Paper end
return regionfile;
} else {
+ // Paper start - cache regionfile does not exist state
+ if (existingOnly && !this.doesRegionFilePossiblyExist(regionPos)) {
+ return null;
+ }
+ // Paper end - cache regionfile does not exist state
if (this.regionCache.size() >= io.papermc.paper.configuration.GlobalConfiguration.get().misc.regionFileCacheSize) { // Paper - configurable
((RegionFile) this.regionCache.removeLast()).close();
}
- FileUtil.createDirectoriesSafe(this.folder);
+ // Paper - only create directory if not existing only - moved down
Path path = this.folder;
int j = chunkcoordintpair.getRegionX();
Path path1 = path.resolve("r." + j + "." + chunkcoordintpair.getRegionZ() + ".mca"); // Paper - diff on change
- if (existingOnly && !java.nio.file.Files.exists(path1)) return null; // CraftBukkit
+ if (existingOnly && !java.nio.file.Files.exists(path1)) { // Paper start - cache regionfile does not exist state
+ this.markNonExisting(regionPos);
+ return null; // CraftBukkit
+ } else {
+ this.createRegionFile(regionPos);
+ }
+ // Paper end - cache regionfile does not exist state
+ FileUtil.createDirectoriesSafe(this.folder); // Paper - only create directory if not existing only - moved from above
RegionFile regionfile1 = new RegionFile(path1, this.folder, this.sync, this.isChunkData); // Paper - allow for chunk regionfiles to regen header
this.regionCache.putAndMoveToFirst(i, regionfile1);