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Micro optimize packet header varint

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This commit is contained in:
themode 2021-03-28 19:34:38 +02:00
parent 3f1d1531ea
commit 85d01e5009
3 changed files with 29 additions and 32 deletions
src/main/java/net/minestom/server/utils
PacketUtils.javaUtils.java
binary
BinaryWriter.java

26
src/main/java/net/minestom/server/utils/PacketUtils.java
View File

@ -198,18 +198,16 @@ public final class PacketUtils {
final int compressionThreshold = MinecraftServer.getCompressionThreshold();
final boolean compression = compressionThreshold > 0;
final int hardcodedVarIntSize = 3;
if (compression) {
// Dummy varint
final int packetLengthIndex = Utils.writeEmptyVarInt(buffer, hardcodedVarIntSize);
final int dataLengthIndex = Utils.writeEmptyVarInt(buffer, hardcodedVarIntSize);
final int packetLengthIndex = Utils.writeEmptyVarIntHeader(buffer);
final int dataLengthIndex = Utils.writeEmptyVarIntHeader(buffer);
// Write packet
final int contentIndex = buffer.writerIndex();
writePacket(buffer, serverPacket);
final int afterIndex = buffer.writerIndex();
final int packetSize = (afterIndex - dataLengthIndex) - hardcodedVarIntSize;
final int packetSize = (afterIndex - dataLengthIndex) - Utils.VARINT_HEADER_SIZE;
if (packetSize >= compressionThreshold) {
// Packet large enough
@ -221,30 +219,30 @@ public final class PacketUtils {
compress(deflater, uncompressedCopy, buffer);
uncompressedCopy.release();
final int totalPacketLength = buffer.writerIndex() - contentIndex + hardcodedVarIntSize;
final int totalPacketLength = buffer.writerIndex() - contentIndex + Utils.VARINT_HEADER_SIZE;
// Update header values
Utils.overrideVarInt(buffer, packetLengthIndex, hardcodedVarIntSize, totalPacketLength);
Utils.overrideVarInt(buffer, dataLengthIndex, hardcodedVarIntSize, packetSize);
Utils.overrideVarIntHeader(buffer, packetLengthIndex, totalPacketLength);
Utils.overrideVarIntHeader(buffer, dataLengthIndex, packetSize);
} else {
// Packet too small, just override header values
final int totalPacketLength = packetSize + hardcodedVarIntSize;
Utils.overrideVarInt(buffer, packetLengthIndex, hardcodedVarIntSize, totalPacketLength);
Utils.overrideVarInt(buffer, dataLengthIndex, hardcodedVarIntSize, 0); // -> Uncompressed
final int totalPacketLength = packetSize + Utils.VARINT_HEADER_SIZE;
Utils.overrideVarIntHeader(buffer, packetLengthIndex, totalPacketLength);
Utils.overrideVarIntHeader(buffer, dataLengthIndex, 0); // -> Uncompressed
}
} else {
// No compression
// Write dummy varint
final int index = Utils.writeEmptyVarInt(buffer, hardcodedVarIntSize);
final int index = Utils.writeEmptyVarIntHeader(buffer);
// Write packet id + payload
writePacket(buffer, serverPacket);
// Rewrite dummy varint to packet length
final int afterIndex = buffer.writerIndex();
final int packetSize = (afterIndex - index) - hardcodedVarIntSize;
Utils.overrideVarInt(buffer, index, hardcodedVarIntSize, packetSize);
final int packetSize = (afterIndex - index) - Utils.VARINT_HEADER_SIZE;
Utils.overrideVarIntHeader(buffer, index, packetSize);
}
}

28
src/main/java/net/minestom/server/utils/Utils.java
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@ -10,6 +10,9 @@ import java.util.UUID;
public final class Utils {
// Do NOT modify
public static final int VARINT_HEADER_SIZE = 3;
private Utils() {
}
@ -44,31 +47,26 @@ public final class Utils {
} while (value != 0);
}
public static void overrideVarInt(@NotNull ByteBuf buffer, int startIndex, int length, int value) {
public static void overrideVarIntHeader(@NotNull ByteBuf buffer, int startIndex, int value) {
final int indexCache = buffer.writerIndex();
buffer.writerIndex(startIndex);
writeVarIntBuf(buffer, value);
final int loopEnd = startIndex + length;
for (int i = startIndex; i < loopEnd; i++) {
byte b = buffer.getByte(i);
boolean last = i == loopEnd - 1;
if (last) {
b &= ~(1 << 7);
} else {
b |= 1 << 7;
for (int i = 0; i < VARINT_HEADER_SIZE; i++) {
byte temp = (byte) (value & 0b01111111);
value >>>= 7;
if (value != 0 || i != VARINT_HEADER_SIZE - 1) {
temp |= 0b10000000;
}
buffer.setByte(i, b);
buffer.writeByte(temp);
}
buffer.writerIndex(indexCache);
}
public static int writeEmptyVarInt(@NotNull ByteBuf buffer, int length) {
public static int writeEmptyVarIntHeader(@NotNull ByteBuf buffer) {
final int index = buffer.writerIndex();
for (int i = 0; i < length; i++) {
buffer.writeByte(0);
}
buffer.writeMedium(0);
return index;
}

7
src/main/java/net/minestom/server/utils/binary/BinaryWriter.java
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@ -1,6 +1,7 @@
package net.minestom.server.utils.binary;
import io.netty.buffer.ByteBuf;
import io.netty.buffer.ByteBufUtil;
import io.netty.buffer.Unpooled;
import net.kyori.adventure.text.Component;
import net.minestom.server.MinecraftServer;
@ -170,9 +171,9 @@ public class BinaryWriter extends OutputStream {
* @param string the string to write
*/
public void writeSizedString(@NotNull String string) {
final byte[] bytes = string.getBytes(StandardCharsets.UTF_8);
writeVarInt(bytes.length);
writeBytes(bytes);
final int utf8Bytes = ByteBufUtil.utf8Bytes(string);
writeVarInt(utf8Bytes);
buffer.writeCharSequence(string, StandardCharsets.UTF_8);
}
/**