3
0
Mirror von https://github.com/PaperMC/Velocity.git synchronisiert 2024-12-25 15:50:19 +01:00

Merge pull request #492 from Leymooo/feature/combine-varint-prefix-with-compression

Do not copy memory in case when packet needs to compress
Dieser Commit ist enthalten in:
Andrew Steinborn 2021-05-08 17:01:56 -04:00 committet von GitHub
Commit 0a4e226571
Es konnte kein GPG-Schlüssel zu dieser Signatur gefunden werden
GPG-Schlüssel-ID: 4AEE18F83AFDEB23
4 geänderte Dateien mit 49 neuen und 22 gelöschten Zeilen

Datei anzeigen

@ -147,6 +147,16 @@ public enum ProtocolUtils {
}
}
/**
* Writes all integers as 3 bytes Minecraft-style VarInt to the specified {@code buf}.
* @param buf the buffer to read from
* @param value the integer to write
*/
public static void writeVarIntAs3Bytes(ByteBuf buf, int value) {
int w = (value & 0x7F | 0x80) << 16 | ((value >>> 7) & 0x7F | 0x80) << 8 | (value >>> 14);
buf.writeMedium(w);
}
public static String readString(ByteBuf buf) {
return readString(buf, DEFAULT_MAX_STRING_SIZE);
}

Datei anzeigen

@ -17,6 +17,8 @@
package com.velocitypowered.proxy.protocol.netty;
import static com.velocitypowered.proxy.protocol.netty.MinecraftVarintLengthEncoder.IS_JAVA_CIPHER;
import com.velocitypowered.natives.compression.VelocityCompressor;
import com.velocitypowered.natives.util.MoreByteBufUtils;
import com.velocitypowered.proxy.protocol.ProtocolUtils;
@ -50,36 +52,37 @@ public class MinecraftCompressorAndLengthEncoder extends MessageToByteEncoder<By
private void handleCompressed(ChannelHandlerContext ctx, ByteBuf msg, ByteBuf out)
throws DataFormatException {
ProtocolUtils.writeVarIntAs3Bytes(out, 0); //Dummy packet length
int uncompressed = msg.readableBytes();
ByteBuf tmpBuf = MoreByteBufUtils.preferredBuffer(ctx.alloc(), compressor, uncompressed - 1);
ProtocolUtils.writeVarInt(out, uncompressed);
ByteBuf compatibleIn = MoreByteBufUtils.ensureCompatible(ctx.alloc(), compressor, msg);
try {
ProtocolUtils.writeVarInt(tmpBuf, uncompressed);
ByteBuf compatibleIn = MoreByteBufUtils.ensureCompatible(ctx.alloc(), compressor, msg);
try {
compressor.deflate(compatibleIn, tmpBuf);
} finally {
compatibleIn.release();
}
ProtocolUtils.writeVarInt(out, tmpBuf.readableBytes());
out.writeBytes(tmpBuf);
compressor.deflate(compatibleIn, out);
} finally {
tmpBuf.release();
compatibleIn.release();
}
int writerIndex = out.writerIndex();
int packetLength = out.readableBytes() - 3;
out.writerIndex(0);
ProtocolUtils.writeVarIntAs3Bytes(out, packetLength); //Rewrite packet length
out.writerIndex(writerIndex);
}
@Override
protected ByteBuf allocateBuffer(ChannelHandlerContext ctx, ByteBuf msg, boolean preferDirect)
throws Exception {
// We allocate bytes to be compressed plus 1 byte. This covers two cases:
//
// - Compression
// According to https://github.com/ebiggers/libdeflate/blob/master/libdeflate.h#L103,
// if the data compresses well (and we do not have some pathological case) then the maximum
// size the compressed size will ever be is the input size minus one.
// - Uncompressed
// This is fairly obvious - we will then have one more than the uncompressed size.
int initialBufferSize = msg.readableBytes() + 1;
int uncompressed = msg.readableBytes();
if (uncompressed < threshold) {
int finalBufferSize = uncompressed + 1;
finalBufferSize += ProtocolUtils.varIntBytes(finalBufferSize);
return IS_JAVA_CIPHER
? ctx.alloc().heapBuffer(finalBufferSize)
: ctx.alloc().directBuffer(finalBufferSize);
}
// (maximum data length after compression) + packet length varint + uncompressed data varint
int initialBufferSize = (uncompressed - 1) + 3 + ProtocolUtils.varIntBytes(uncompressed);
return MoreByteBufUtils.preferredBuffer(ctx.alloc(), compressor, initialBufferSize);
}

Datei anzeigen

@ -29,7 +29,7 @@ import io.netty.handler.codec.MessageToByteEncoder;
public class MinecraftVarintLengthEncoder extends MessageToByteEncoder<ByteBuf> {
public static final MinecraftVarintLengthEncoder INSTANCE = new MinecraftVarintLengthEncoder();
private static final boolean IS_JAVA_CIPHER = Natives.cipher.get() == JavaVelocityCipher.FACTORY;
public static final boolean IS_JAVA_CIPHER = Natives.cipher.get() == JavaVelocityCipher.FACTORY;
private MinecraftVarintLengthEncoder() {
}

Datei anzeigen

@ -71,6 +71,20 @@ public class ProtocolUtilsTest {
assertEquals(test, ProtocolUtils.readVarIntSafely(buf));
}
@Test
void test3Bytes() {
ByteBuf buf = Unpooled.buffer(5);
for (int i = 0; i < 2097152; i += 31) {
writeReadTest3Bytes(buf, i);
}
}
private void writeReadTest3Bytes(ByteBuf buf, int test) {
buf.clear();
ProtocolUtils.writeVarIntAs3Bytes(buf, test);
assertEquals(test, ProtocolUtils.readVarInt(buf));
}
@Test
void testBytesWrittenAtBitBoundaries() {
ByteBuf varintNew = Unpooled.buffer(5);