Class PacketIO

java.lang.Object

com.hypixel.hytale.protocol.io.PacketIO

public final class PacketIO
extends Object

Utility class for reading and writing protocol data.

Field Summary

Fields

Modifier and Type	Field	Description
static final Charset	ASCII
static final int	FRAME_HEADER_SIZE	Header size for framed packets (4 bytes for packet ID).
static final int	PACKET_HEADER_SIZE	Packet header size, 4 bytes for id, 4 bytes for length
static final ValueLayout.OfBoolean	PROTO_BOOL
static final ValueLayout.OfByte	PROTO_BYTE
static final ValueLayout.OfDouble	PROTO_DOUBLE
static final ValueLayout.OfFloat	PROTO_FLOAT
static final ValueLayout.OfInt	PROTO_INT
static final ValueLayout.OfLong	PROTO_LONG
static final ValueLayout.OfShort	PROTO_SHORT
static final Charset	UTF8
static final ValueLayout.OfLong	UUID_LONG
static final org.joml.Matrix4fc	ZERO_MATRIX
static final org.joml.Quaternionfc	ZERO_QUATERNION
static final org.joml.Vector2fc	ZERO_VECTOR2
static final org.joml.Vector3fc	ZERO_VECTOR3
static final org.joml.Vector4fc	ZERO_VECTOR4

Method Summary

Modifier and Type	Method	Description
static short	floatToHalf(float f)
static float	halfToFloat(short half)
static boolean	isFinite(double value)	True if value is finite.
static boolean	isFinite(float value)	True if value is finite.
static boolean	isFinite(org.joml.Matrix4fc m)	True if every one of the 16 components of m is finite.
static boolean	isFinite(org.joml.Quaternionfc q)	True if every component of q is finite.
static boolean	isFinite(org.joml.Vector2fc v)	True if every component of v is finite.
static boolean	isFinite(org.joml.Vector3fc v)	True if every component of v is finite.
static boolean	isFinite(org.joml.Vector4fc v)	True if every component of v is finite.
static boolean	isWellFormedUtf8(byte[] bytes)	Table 3-7 of the Unicode standard.
static byte[]	readBytes(io.netty.buffer.ByteBuf buf, int offset, int length)
static String	readFixedAsciiString(io.netty.buffer.ByteBuf buf, int offset, int length)
static String	readFixedAsciiString(MemorySegment mem, int offset, int length)
static String	readFixedString(io.netty.buffer.ByteBuf buf, int offset, int length)
static String	readFixedString(MemorySegment mem, int offset, int length)
static Packet	readFramedPacket(io.netty.buffer.ByteBuf in, int payloadLength, io.netty.buffer.ByteBufAllocator allocator, PacketStatsRecorder statsRecorder)	Read a framed packet from a ByteBuf.
static Packet	readFramedPacket(MemorySegment decompressionContext, MemorySegment in, int payloadLength, PacketStatsRecorder statsRecorder)
static Packet	readFramedPacketWithInfo(io.netty.buffer.ByteBuf in, int payloadLength, io.netty.buffer.ByteBufAllocator allocator, PacketRegistry.PacketInfo info, PacketStatsRecorder statsRecorder)	Read a framed packet with pre-validated PacketInfo (packet ID and size already validated).
static Packet	readFramedPacketWithInfo(MemorySegment decompressionContext, MemorySegment in, int offset, int payloadLength, PacketRegistry.PacketInfo info, PacketStatsRecorder statsRecorder)
static org.joml.Quaternionf	readQuaternionf(MemorySegment mem, int offset)
static UUID	readUUID(io.netty.buffer.ByteBuf buf, int offset)
static UUID	readUUID(MemorySegment mem, int offset)
static String	readValidatedAsciiString(io.netty.buffer.ByteBuf buf, int offset, int length, String fieldName)	Reads bytes from the buffer, validates they are ASCII (0-127), and returns the decoded string.
static String	readValidatedAsciiString(String fieldName, MemorySegment mem, int offset, int maxLength)
static String	readValidatedAsciiString(String fieldName, MemorySegment mem, int offset, int minLength, int maxLength)	Reads a length-prefixed ASCII string from a MemorySegment, validating every byte is in the ASCII range (0-127).
static String	readValidatedAsciiString(String fieldName, MemorySegment mem, int offset, int minLength, int maxLength, long packed)	The packed parameter is the VarInt.getWithLength result for offset, so a caller that already decoded the prefix does not decode it twice.
static String	readVarString(io.netty.buffer.ByteBuf buf, int offset)
static String	readVarString(io.netty.buffer.ByteBuf buf, int offset, Charset charset)
static String	readVarString(String fieldName, MemorySegment mem, int offset, int maxLength)
static String	readVarString(String fieldName, MemorySegment mem, int offset, int minLength, int maxLength)
static String	readVarString(String fieldName, MemorySegment mem, int offset, int minLength, int maxLength, long packed)	The packed parameter is the VarInt.getWithLength result for offset, so a caller that already decoded the prefix does not decode it twice.
static org.joml.Vector2f	readVector2f(MemorySegment mem, int offset)
static org.joml.Vector3f	readVector3f(MemorySegment mem, int offset)
static org.joml.Vector4f	readVector4f(MemorySegment mem, int offset)
static double	requireFinite(double value, String fieldName)	Returns value if it is finite, otherwise throws.
static float	requireFinite(float value, String fieldName)	Returns value if it is finite (not NaN and not infinite), otherwise throws a ProtocolException.
static org.joml.Matrix4fc	requireFinite(org.joml.Matrix4fc m, String fieldName)	Returns m if every component is finite, otherwise throws.
static org.joml.Quaternionfc	requireFinite(org.joml.Quaternionfc q, String fieldName)	Returns q if every component is finite, otherwise throws.
static org.joml.Vector2fc	requireFinite(org.joml.Vector2fc v, String fieldName)	Returns v if every component is finite, otherwise throws.
static org.joml.Vector3fc	requireFinite(org.joml.Vector3fc v, String fieldName)	Returns v if every component is finite, otherwise throws.
static org.joml.Vector4fc	requireFinite(org.joml.Vector4fc v, String fieldName)	Returns v if every component is finite, otherwise throws.
static int	stringSize(String s)	Compute the total wire size of a VarInt-prefixed UTF-8 string.
static int	utf8ByteLength(String s)	Compute the number of UTF-8 bytes needed to encode a string.
static void	writeFixedAsciiString(io.netty.buffer.ByteBuf buf, String value, int length)
static void	writeFixedAsciiString(MemorySegment mem, int offset, String value, int length)
static void	writeFixedString(io.netty.buffer.ByteBuf buf, String value, int length)
static void	writeFixedString(MemorySegment mem, int offset, String value, int length)
static void	writeFramedPacket(Packet packet, Class<? extends Packet> packetClass, io.netty.buffer.ByteBuf out, io.netty.buffer.ByteBufAllocator allocator, PacketStatsRecorder statsRecorder)	Write a packet with framing, using an explicit packet class for registry lookup.
static int	writeFramedPacket(MemorySegment compressionContext, Packet packet, PacketRegistry.PacketInfo packetInfo, MemorySegment out, int offset, int packetSize, PacketStatsRecorder statsRecorder)
static void	writeFramedPacketWithInfo(Packet packet, PacketRegistry.PacketInfo info, io.netty.buffer.ByteBuf out, io.netty.buffer.ByteBufAllocator allocator, PacketStatsRecorder statsRecorder)
static void	writeQuaternionf(MemorySegment mem, int offset, org.joml.Quaternionfc q)
static void	writeUUID(io.netty.buffer.ByteBuf buf, UUID value)
static void	writeUUID(MemorySegment mem, int offset, UUID value)
static void	writeVarAsciiString(io.netty.buffer.ByteBuf buf, String value, int maxLength)
static int	writeVarAsciiString(MemorySegment mem, int offset, String value, int maxLength)
static void	writeVarString(io.netty.buffer.ByteBuf buf, String value, int maxLength)
static int	writeVarString(MemorySegment mem, int offset, String value, int maxLength)
static void	writeVector2f(MemorySegment mem, int offset, org.joml.Vector2fc v)
static void	writeVector3f(MemorySegment mem, int offset, org.joml.Vector3fc v)
static void	writeVector4f(MemorySegment mem, int offset, org.joml.Vector4fc v)

Methods inherited from class Object

equals, getClass, hashCode, notify, notifyAll, toString, wait, wait, wait

Field Details

FRAME_HEADER_SIZE

public static final int FRAME_HEADER_SIZE

Header size for framed packets (4 bytes for packet ID).

See Also:

• Constant Field Values

PACKET_HEADER_SIZE

public static final int PACKET_HEADER_SIZE

Packet header size, 4 bytes for id, 4 bytes for length

See Also:

• Constant Field Values

UTF8

public static final Charset UTF8

ASCII

public static final Charset ASCII

PROTO_BOOL

public static final ValueLayout.OfBoolean PROTO_BOOL

PROTO_BYTE

public static final ValueLayout.OfByte PROTO_BYTE

PROTO_SHORT

public static final ValueLayout.OfShort PROTO_SHORT

PROTO_INT

public static final ValueLayout.OfInt PROTO_INT

PROTO_LONG

public static final ValueLayout.OfLong PROTO_LONG

PROTO_FLOAT

public static final ValueLayout.OfFloat PROTO_FLOAT

PROTO_DOUBLE

public static final ValueLayout.OfDouble PROTO_DOUBLE

UUID_LONG

public static final ValueLayout.OfLong UUID_LONG

ZERO_VECTOR2

public static final org.joml.Vector2fc ZERO_VECTOR2

ZERO_VECTOR3

public static final org.joml.Vector3fc ZERO_VECTOR3

ZERO_VECTOR4

public static final org.joml.Vector4fc ZERO_VECTOR4

ZERO_QUATERNION

public static final org.joml.Quaternionfc ZERO_QUATERNION

ZERO_MATRIX

public static final org.joml.Matrix4fc ZERO_MATRIX

Method Details

readBytes

@Nonnull
public static byte[] readBytes(@Nonnull
 io.netty.buffer.ByteBuf buf,
 int offset,
 int length)

readFixedAsciiString

@Nonnull
public static String readFixedAsciiString(@Nonnull
 io.netty.buffer.ByteBuf buf,
 int offset,
 int length)

readFixedString

@Nonnull
public static String readFixedString(@Nonnull
 io.netty.buffer.ByteBuf buf,
 int offset,
 int length)

readFixedAsciiString

@Nonnull
public static String readFixedAsciiString(@Nonnull
 MemorySegment mem,
 int offset,
 int length)

readFixedString

@Nonnull
public static String readFixedString(@Nonnull
 MemorySegment mem,
 int offset,
 int length)

readVarString

@Nonnull
public static String readVarString(@Nonnull
 io.netty.buffer.ByteBuf buf,
 int offset)

readVarString

@Nonnull
public static String readVarString(@Nonnull
 io.netty.buffer.ByteBuf buf,
 int offset,
 Charset charset)

readValidatedAsciiString

@Nonnull
public static String readValidatedAsciiString(@Nonnull
 io.netty.buffer.ByteBuf buf,
 int offset,
 int length,
 @Nonnull
 String fieldName)

Reads bytes from the buffer, validates they are ASCII (0-127), and returns the decoded string. Combines validation and reading in a single pass over the bytes.

Throws:

ProtocolException - if any byte is outside the ASCII range

readVarString

@Nonnull
public static String readVarString(String fieldName,
 @Nonnull
 MemorySegment mem,
 int offset,
 int minLength,
 int maxLength)

readVarString

@Nonnull
public static String readVarString(String fieldName,
 @Nonnull
 MemorySegment mem,
 int offset,
 int minLength,
 int maxLength,
 long packed)

The packed parameter is the VarInt.getWithLength result for offset, so a caller that already decoded the prefix does not decode it twice.

isWellFormedUtf8

public static boolean isWellFormedUtf8(@Nonnull
 byte[] bytes)

Table 3-7 of the Unicode standard. Decoding substitutes U+FFFD rather than rejecting, and Java and .NET disagree on how many it substitutes for one ill-formed sequence, so neither the decoded length nor a re-encoded length is a portable test. Both decode walks have to accept exactly the same bytes, or one end rejects a payload the other end accepted.

readVarString

@Nonnull
public static String readVarString(String fieldName,
 @Nonnull
 MemorySegment mem,
 int offset,
 int maxLength)

readValidatedAsciiString

@Nonnull
public static String readValidatedAsciiString(String fieldName,
 @Nonnull
 MemorySegment mem,
 int offset,
 int minLength,
 int maxLength)

Reads a length-prefixed ASCII string from a MemorySegment, validating every byte is in the ASCII range (0-127). Mirrors readValidatedAsciiString(ByteBuf, int, int, String) so FFM-emitted readers reject non-ASCII payloads instead of silently replacing bytes with ? via StandardCharsets.US_ASCII.

readValidatedAsciiString

@Nonnull
public static String readValidatedAsciiString(String fieldName,
 @Nonnull
 MemorySegment mem,
 int offset,
 int minLength,
 int maxLength,
 long packed)

The packed parameter is the VarInt.getWithLength result for offset, so a caller that already decoded the prefix does not decode it twice.

readValidatedAsciiString

@Nonnull
public static String readValidatedAsciiString(String fieldName,
 @Nonnull
 MemorySegment mem,
 int offset,
 int maxLength)

requireFinite

public static float requireFinite(float value,
 @Nonnull
 String fieldName)

Returns value if it is finite (not NaN and not infinite), otherwise throws a ProtocolException. Apply to any float field that must carry only valid finite wire values.

requireFinite

public static double requireFinite(double value,
 @Nonnull
 String fieldName)

Returns value if it is finite, otherwise throws. See requireFinite(float, String).

isFinite

public static boolean isFinite(float value)

True if value is finite. No-throw counterpart of requireFinite(float, String), used by the structural validator.

isFinite

public static boolean isFinite(double value)

True if value is finite. No-throw counterpart of requireFinite(double, String), used by the structural validator.

isFinite

public static boolean isFinite(@Nonnull
 org.joml.Vector2fc v)

True if every component of v is finite.

isFinite

public static boolean isFinite(@Nonnull
 org.joml.Vector3fc v)

True if every component of v is finite.

isFinite

public static boolean isFinite(@Nonnull
 org.joml.Vector4fc v)

True if every component of v is finite.

isFinite

public static boolean isFinite(@Nonnull
 org.joml.Quaternionfc q)

True if every component of q is finite.

isFinite

public static boolean isFinite(@Nonnull
 org.joml.Matrix4fc m)

True if every one of the 16 components of m is finite.

requireFinite

@Nonnull
public static org.joml.Vector2fc requireFinite(@Nonnull
 org.joml.Vector2fc v,
 @Nonnull
 String fieldName)

Returns v if every component is finite, otherwise throws. Composite counterpart of requireFinite(float, String).

requireFinite

@Nonnull
public static org.joml.Vector3fc requireFinite(@Nonnull
 org.joml.Vector3fc v,
 @Nonnull
 String fieldName)

Returns v if every component is finite, otherwise throws. Composite counterpart of requireFinite(float, String).

requireFinite

@Nonnull
public static org.joml.Vector4fc requireFinite(@Nonnull
 org.joml.Vector4fc v,
 @Nonnull
 String fieldName)

Returns v if every component is finite, otherwise throws. Composite counterpart of requireFinite(float, String).

requireFinite

@Nonnull
public static org.joml.Quaternionfc requireFinite(@Nonnull
 org.joml.Quaternionfc q,
 @Nonnull
 String fieldName)

Returns q if every component is finite, otherwise throws. Composite counterpart of requireFinite(float, String).

requireFinite

@Nonnull
public static org.joml.Matrix4fc requireFinite(@Nonnull
 org.joml.Matrix4fc m,
 @Nonnull
 String fieldName)

Returns m if every component is finite, otherwise throws. Composite counterpart of requireFinite(float, String).

utf8ByteLength

public static int utf8ByteLength(@Nonnull
 String s)

Compute the number of UTF-8 bytes needed to encode a string. This avoids actually encoding the string just to get its byte count.

stringSize

public static int stringSize(@Nonnull
 String s)

Compute the total wire size of a VarInt-prefixed UTF-8 string. This is VarInt.size(byteLength) + byteLength, computed without double-encoding.

writeFixedAsciiString

public static void writeFixedAsciiString(@Nonnull
 io.netty.buffer.ByteBuf buf,
 @Nullable
 String value,
 int length)

writeFixedString

public static void writeFixedString(@Nonnull
 io.netty.buffer.ByteBuf buf,
 @Nullable
 String value,
 int length)

writeVarString

public static void writeVarString(@Nonnull
 io.netty.buffer.ByteBuf buf,
 @Nonnull
 String value,
 int maxLength)

writeVarAsciiString

public static void writeVarAsciiString(@Nonnull
 io.netty.buffer.ByteBuf buf,
 @Nonnull
 String value,
 int maxLength)

writeVarString

public static int writeVarString(@Nonnull
 MemorySegment mem,
 int offset,
 @Nonnull
 String value,
 int maxLength)

writeVarAsciiString

public static int writeVarAsciiString(@Nonnull
 MemorySegment mem,
 int offset,
 @Nonnull
 String value,
 int maxLength)

readVector2f

@Nonnull
public static org.joml.Vector2f readVector2f(@Nonnull
 MemorySegment mem,
 int offset)

readVector3f

@Nonnull
public static org.joml.Vector3f readVector3f(@Nonnull
 MemorySegment mem,
 int offset)

readVector4f

@Nonnull
public static org.joml.Vector4f readVector4f(@Nonnull
 MemorySegment mem,
 int offset)

readQuaternionf

@Nonnull
public static org.joml.Quaternionf readQuaternionf(@Nonnull
 MemorySegment mem,
 int offset)

writeVector2f

public static void writeVector2f(@Nonnull
 MemorySegment mem,
 int offset,
 @Nonnull
 org.joml.Vector2fc v)

writeVector3f

public static void writeVector3f(@Nonnull
 MemorySegment mem,
 int offset,
 @Nonnull
 org.joml.Vector3fc v)

writeVector4f

public static void writeVector4f(@Nonnull
 MemorySegment mem,
 int offset,
 @Nonnull
 org.joml.Vector4fc v)

writeQuaternionf

public static void writeQuaternionf(@Nonnull
 MemorySegment mem,
 int offset,
 @Nonnull
 org.joml.Quaternionfc q)

writeFixedAsciiString

public static void writeFixedAsciiString(@Nonnull
 MemorySegment mem,
 int offset,
 @Nullable
 String value,
 int length)

writeFixedString

public static void writeFixedString(@Nonnull
 MemorySegment mem,
 int offset,
 @Nullable
 String value,
 int length)

readUUID

@Nonnull
public static UUID readUUID(@Nonnull
 io.netty.buffer.ByteBuf buf,
 int offset)

writeUUID

public static void writeUUID(@Nonnull
 io.netty.buffer.ByteBuf buf,
 @Nonnull
 UUID value)

readUUID

@Nonnull
public static UUID readUUID(@Nonnull
 MemorySegment mem,
 int offset)

writeUUID

public static void writeUUID(@Nonnull
 MemorySegment mem,
 int offset,
 @Nonnull
 UUID value)

halfToFloat

public static float halfToFloat(short half)

floatToHalf

public static short floatToHalf(float f)

writeFramedPacket

public static void writeFramedPacket(@Nonnull
 Packet packet,
 @Nonnull
 Class<? extends Packet> packetClass,
 @Nonnull
 io.netty.buffer.ByteBuf out,
 @Nonnull
 io.netty.buffer.ByteBufAllocator allocator,
 @Nonnull
 PacketStatsRecorder statsRecorder)

Write a packet with framing, using an explicit packet class for registry lookup. This is needed for CachedPacket where the actual class differs from the registered type. Wire format: [4-byte payload length] [4-byte packet ID] [payload]

Parameters:

packet - the packet to write

packetClass - the class to use for registry lookup

out - the ByteBuf to write to

allocator - the buffer allocator to use for temporary buffers

statsRecorder - the recorder for capturing packet statistics

writeFramedPacketWithInfo

public static void writeFramedPacketWithInfo(@Nonnull
 Packet packet,
 @Nonnull
 PacketRegistry.PacketInfo info,
 @Nonnull
 io.netty.buffer.ByteBuf out,
 @Nonnull
 io.netty.buffer.ByteBufAllocator allocator,
 @Nonnull
 PacketStatsRecorder statsRecorder)

readFramedPacket

@Nonnull
public static Packet readFramedPacket(@Nonnull
 io.netty.buffer.ByteBuf in,
 int payloadLength,
 @Nonnull
 io.netty.buffer.ByteBufAllocator allocator,
 @Nonnull
 PacketStatsRecorder statsRecorder)

Read a framed packet from a ByteBuf. The buffer should be positioned at the packet ID (after the length prefix has been consumed). Handles decompression based on packet definition. Wire format: [4-byte payload length] [4-byte packet ID] [payload]

Parameters:

in - the ByteBuf positioned at packet ID

payloadLength - the payload length (not including packet ID)

allocator - the buffer allocator to use for decompression buffers

statsRecorder - the recorder for capturing packet statistics

Returns:

the deserialized packet, or null if packet ID is unknown

readFramedPacketWithInfo

@Nonnull
public static Packet readFramedPacketWithInfo(@Nonnull
 io.netty.buffer.ByteBuf in,
 int payloadLength,
 @Nonnull
 io.netty.buffer.ByteBufAllocator allocator,
 @Nonnull
 PacketRegistry.PacketInfo info,
 @Nonnull
 PacketStatsRecorder statsRecorder)

Read a framed packet with pre-validated PacketInfo (packet ID and size already validated). Used by PacketDecoder for fail-fast validation - packet ID is validated before waiting for payload.

Parameters:

in - the ByteBuf positioned at payload start (after packet ID)

payloadLength - the payload length (already validated against info.maxSize())

allocator - the buffer allocator to use for decompression buffers

info - the pre-validated packet info

statsRecorder - the recorder for capturing packet statistics

Returns:

the deserialized packet

writeFramedPacket

public static int writeFramedPacket(@Nonnull
 MemorySegment compressionContext,
 @Nonnull
 Packet packet,
 @Nonnull
 PacketRegistry.PacketInfo packetInfo,
 @Nonnull
 MemorySegment out,
 int offset,
 int packetSize,
 @Nonnull
 PacketStatsRecorder statsRecorder)

readFramedPacket

@Nonnull
public static Packet readFramedPacket(@Nonnull
 MemorySegment decompressionContext,
 @Nonnull
 MemorySegment in,
 int payloadLength,
 @Nonnull
 PacketStatsRecorder statsRecorder)

readFramedPacketWithInfo

@Nonnull
public static Packet readFramedPacketWithInfo(@Nonnull
 MemorySegment decompressionContext,
 @Nonnull
 MemorySegment in,
 int offset,
 int payloadLength,
 @Nonnull
 PacketRegistry.PacketInfo info,
 @Nonnull
 PacketStatsRecorder statsRecorder)