Paper/patches/server/0635-Only-write-chunk-data-to-disk-if-it-serializes-witho.patch
Bjarne Koll c5a10665b8
Remove wall-time / unused skip tick protection (#11412)
Spigot still maintains some partial implementation of "tick skipping", a
practice in which the MinecraftServer.currentTick field is updated not
by an increment of one per actual tick, but instead set to
System.currentTimeMillis() / 50. This behaviour means that the tracked
tick may "skip" a tick value in case a previous tick took more than the
expected 50ms.

To compensate for this in important paths, spigot/craftbukkit
implements "wall-time". Instead of incrementing/decrementing ticks on
block entities/entities by one for each call to their tick() method,
they instead increment/decrement important values, like
an ItemEntity's age or pickupDelay, by the difference of
`currentTick - lastTick`, where `lastTick` is the value of
`currentTick` during the last tick() call.

These "fixes" however do not play nicely with minecraft's simulation
distance as entities/block entities implementing the above behaviour
would "catch up" their values when moving from a non-ticking chunk to a
ticking one as their `lastTick` value remains stuck on the last tick in
a ticking chunk and hence lead to a large "catch up" once ticked again.

Paper completely removes the "tick skipping" behaviour (See patch
"Further-improve-server-tick-loop"), making the above precautions
completely unnecessary, which also rids paper of the previous described
incompatibility with non-ticking chunks.
2024-09-19 16:36:07 +02:00

95 lines
4.5 KiB
Diff

From 0000000000000000000000000000000000000000 Mon Sep 17 00:00:00 2001
From: Spottedleaf <Spottedleaf@users.noreply.github.com>
Date: Sun, 19 Dec 2021 09:13:41 -0800
Subject: [PATCH] Only write chunk data to disk if it serializes without
throwing
This ensures at least a valid version of the chunk exists
on disk, even if outdated
diff --git a/src/main/java/net/minecraft/world/level/chunk/storage/RegionFile.java b/src/main/java/net/minecraft/world/level/chunk/storage/RegionFile.java
index 12b7d50f49a2184aaf220a4a50a137b217c57124..f1237f6fd6414900ffbad0caee31aa83310eeef4 100644
--- a/src/main/java/net/minecraft/world/level/chunk/storage/RegionFile.java
+++ b/src/main/java/net/minecraft/world/level/chunk/storage/RegionFile.java
@@ -442,6 +442,7 @@ public class RegionFile implements AutoCloseable {
}
+ public static final int MAX_CHUNK_SIZE = 500 * 1024 * 1024; // Paper - don't write garbage data to disk if writing serialization fails
private class ChunkBuffer extends ByteArrayOutputStream {
private final ChunkPos pos;
@@ -455,6 +456,23 @@ public class RegionFile implements AutoCloseable {
super.write(RegionFile.this.version.getId());
this.pos = chunkcoordintpair;
}
+ // Paper start - don't write garbage data to disk if writing serialization fails
+ @Override
+ public void write(final int b) {
+ if (this.count > MAX_CHUNK_SIZE) {
+ throw new RegionFileStorage.RegionFileSizeException("Region file too large: " + this.count);
+ }
+ super.write(b);
+ }
+
+ @Override
+ public void write(final byte[] b, final int off, final int len) {
+ if (this.count + len > MAX_CHUNK_SIZE) {
+ throw new RegionFileStorage.RegionFileSizeException("Region file too large: " + (this.count + len));
+ }
+ super.write(b, off, len);
+ }
+ // Paper end - don't write garbage data to disk if writing serialization fails
public void close() throws IOException {
ByteBuffer bytebuffer = ByteBuffer.wrap(this.buf, 0, this.count);
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 491035aaefff4ee96435ec5d3f9417e28eae0796..4c1212c6ef48594e766fa9e35a6e15916602d587 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
@@ -147,10 +147,17 @@ public final class RegionFileStorage implements AutoCloseable {
try {
NbtIo.write(nbt, (DataOutput) dataoutputstream);
+ // Paper start - don't write garbage data to disk if writing serialization fails
+ dataoutputstream.close(); // Only write if successful
+ } catch (final RegionFileSizeException e) {
+ attempts = 5; // Don't retry
+ regionfile.clear(pos);
+ throw e;
+ // Paper end - don't write garbage data to disk if writing serialization fails
} catch (Throwable throwable) {
if (dataoutputstream != null) {
try {
- dataoutputstream.close();
+ //dataoutputstream.close(); // Paper - don't write garbage data to disk if writing serialization fails
} catch (Throwable throwable1) {
throwable.addSuppressed(throwable1);
}
@@ -158,10 +165,7 @@ public final class RegionFileStorage implements AutoCloseable {
throw throwable;
}
-
- if (dataoutputstream != null) {
- dataoutputstream.close();
- }
+ // Paper - don't write garbage data to disk if writing serialization fails; move into try block to only write if successfully serialized
}
// Paper start - Chunk save reattempt
return;
@@ -208,4 +212,13 @@ public final class RegionFileStorage implements AutoCloseable {
public RegionStorageInfo info() {
return this.info;
}
+
+ // Paper start - don't write garbage data to disk if writing serialization fails
+ public static final class RegionFileSizeException extends RuntimeException {
+
+ public RegionFileSizeException(String message) {
+ super(message);
+ }
+ }
+ // Paper end - don't write garbage data to disk if writing serialization fails
}