StreamCodecUtil

StreamCodecUtil focuses on StreamCodec for network packets, providing compact binary serialization for common game objects as well as higher-order combinators.

Built-in Stream Codecs

Field	Applicable Buffer	Description
ITEM	RegistryFriendlyByteBuf	Reads/writes items by registry ID
BLOCK	RegistryFriendlyByteBuf	Reads/writes blocks by registry ID
ENTITY	RegistryFriendlyByteBuf	Entity type stream codec
CHAR	RegistryFriendlyByteBuf	Single character UTF stream codec
VAR_INT_BLOCK_POS	FriendlyByteBuf	BlockPos encoded with VarInt
BLOCK_STATE	ByteBuf	Block state encoded by global runtime state ID
VEC3	FriendlyByteBuf	Vec3 with three float components
VEC3I	ByteBuf	Vec3i packed as a long (same packing as BlockPos)
NUMBER_PROVIDER	RegistryFriendlyByteBuf	Compact NumberProvider variant encoding (Const / Uniform / Binomial)

Bridging and Conversion

codec2Stream

Converts a registry-context Codec<T> to a StreamCodec<RegistryFriendlyByteBuf, T> via NBT relay:

StreamCodec<RegistryFriendlyByteBuf, MyType> streamCodec =
    StreamCodecUtil.codec2Stream(MyType.CODEC);

Suitable for types that already have a Codec, eliminating the need to manually write network serialization.

nbtWrapped

Wraps a Codec<T> as an NBT-based StreamCodec<FriendlyByteBuf, T>:

StreamCodec<FriendlyByteBuf, MyType> streamCodec =
    StreamCodecUtil.nbtWrapped(MyType.CODEC);

Commonly used for compatibility with legacy protocol scenarios.

Higher-Order composite Methods

Provides composite overloads for 7 to 16 parameters, combining the encoding/decoding of multiple fields in order:

StreamCodec<B, C> composite(
    StreamCodec<? super B, T1> codec1, Function<C, T1> getter1,
    StreamCodec<? super B, T2> codec2, Function<C, T2> getter2,
    ... ,
    C factory
);

Each composite reads from the buffer in order during decoding and writes in getter order during encoding. Supports Function7 through Function16 as factory methods.

Example: 7-field Object

public static final StreamCodec<RegistryFriendlyByteBuf, MyObject> STREAM_CODEC =
    StreamCodecUtil.composite(
        StreamCodecUtil.ITEM,          MyObject::item,
        ByteBufCodecs.VAR_INT,         MyObject::count,
        BlockPos.STREAM_CODEC,         MyObject::pos,
        StreamCodecUtil.VEC3,          MyObject::offset,
        ByteBufCodecs.BOOL,            MyObject::flag1,
        ByteBufCodecs.BOOL,            MyObject::flag2,
        ByteBufCodecs.UTF_8,           MyObject::name,
        MyObject::new
    );

Other Utility Methods

Method	Description
enumStreamCodec(Class<T>)	Ordinal-based enum stream codec
createPairStreamCodec(first, second)	Combines two StreamCodecs into a Pair<F, S> codec
numberProviderNetworkEncode(buf, np)	Manually writes the binary format of a NumberProvider
numberProviderNetworkDecode(buf)	Manually reads the binary format of a NumberProvider

Usage Recommendations

• For fewer than 7 fields, prefer the official StreamCodec.composite overloads (1-6 parameters)
• For 7-16 fields, use StreamCodecUtil.composite
• codec2Stream routes through NBT and incurs a performance cost; for frequently used network packets, consider manually writing the StreamCodec
• NUMBER_PROVIDER's STREAM_CODEC preserves precision: integer ConstantValues are compressed to a single byte tag + float