Fix other code for compatible with new go-mc/net packet

bot/ingame.go

@@ -294,22 +294,16 @@ func handleEntityStatusPacket(c *Client, p pk.Packet) error {
 }
 
 func handleDestroyEntitiesPacket(c *Client, p pk.Packet) error {
-	var (
+	var count pk.VarInt
-		count pk.VarInt
+	var data = pk.Ary{
-		r     = bytes.NewReader(p.Data)
+		Len: &count,
-	)
+		Ary: []pk.VarInt{},
-	if err := count.Decode(r); err != nil {
+	}
+	if err := p.Scan(&count, &data); err != nil {
 		return err
 	}
 
-	entities := make([]pk.VarInt, int(count))
+	return c.Wd.OnEntityDestroy(data.Ary.([]pk.VarInt))
-	for i := 0; i < int(count); i++ {
-		if err := entities[i].Decode(r); err != nil {
-			return err
-		}
-	}
-
-	return c.Wd.OnEntityDestroy(entities)
 }
 
 func handleSoundEffect(c *Client, p pk.Packet) error {
@@ -378,34 +372,24 @@ func handleMultiBlockChangePacket(c *Client, p pk.Packet) error {
 	if !c.settings.ReceiveMap {
 		return nil
 	}
-	r := bytes.NewReader(p.Data)
 
 	var (
 		loc            pk.Long
 		dontTrustEdges pk.Boolean
 		sz             pk.VarInt
+		packedBlocks   = pk.Ary{
+			Len: &sz,
+			Ary: []pk.VarLong{},
+		}
 	)
-
+	err := p.Scan(&loc, &dontTrustEdges, &sz, &packedBlocks)
-	if err := loc.Decode(r); err != nil {
+	if err != nil {
-		return fmt.Errorf("packed location: %v", err)
+		return err
-	}
-	if err := dontTrustEdges.Decode(r); err != nil {
-		return fmt.Errorf("unknown 1: %v", err)
-	}
-	if err := sz.Decode(r); err != nil {
-		return fmt.Errorf("array size: %v", err)
 	}
 
-	packedBlocks := make([]pk.VarLong, int(sz))
+	x := int((loc >> 42) & ((1 << 22) - 1))
-	for i := 0; i < int(sz); i++ {
+	y := int((loc >> 20) & ((1 << 22) - 1))
-		if err := packedBlocks[i].Decode(r); err != nil {
+	z := int(loc & ((1 << 20) - 1))
-			return fmt.Errorf("block[%d]: %v", i, err)
-		}
-	}
-
-	x, z, y := int((loc>>42)&((1<<22)-1)),
-		int((loc>>20)&((1<<22)-1)),
-		int(loc&((1<<20)-1))
 
 	// Apply transform into negative (these numbers are signed)
 	if x >= 1<<21 {
@@ -415,7 +399,7 @@ func handleMultiBlockChangePacket(c *Client, p pk.Packet) error {
 		z -= 1 << 22
 	}
 
-	c.Wd.MultiBlockUpdate(world.ChunkLoc{X: x, Z: z}, y, packedBlocks)
+	c.Wd.MultiBlockUpdate(world.ChunkLoc{X: x, Z: z}, y, packedBlocks.Ary.([]pk.VarLong))
 	return nil
 }
 
@@ -520,14 +504,14 @@ func handlePluginPacket(c *Client, p pk.Packet) error {
 	switch msg.Channel {
 	case "minecraft:brand":
 		var brandRaw pk.String
-		if err := brandRaw.Decode(bytes.NewReader(msg.Data)); err != nil {
+		if _, err := brandRaw.ReadFrom(bytes.NewReader(msg.Data)); err != nil {
 			return err
 		}
 		c.ServInfo.Brand = string(brandRaw)
 	}
 
 	if c.Events.PluginMessage != nil {
-		return c.Events.PluginMessage(string(msg.Channel), []byte(msg.Data))
+		return c.Events.PluginMessage(string(msg.Channel), msg.Data)
 	}
 	return nil
 }
@@ -622,7 +606,7 @@ func handleChunkDataPacket(c *Client, p pk.Packet) error {
 	}
 
 	var pkt ptypes.ChunkData
-	if err := pkt.Decode(p); err != nil {
+	if _, err := pkt.ReadFrom(bytes.NewReader(p.Data)); err != nil {
 		return err
 	}
 
@@ -641,7 +625,7 @@ func handleChunkDataPacket(c *Client, p pk.Packet) error {
 
 func handleTileEntityDataPacket(c *Client, p pk.Packet) error {
 	var pkt ptypes.TileEntityData
-	if err := pkt.Decode(p); err != nil {
+	if _, err := pkt.ReadFrom(bytes.NewReader(p.Data)); err != nil {
 		return err
 	}
 	return c.Wd.TileEntityUpdate(pkt)
@@ -712,7 +696,7 @@ func handleKeepAlivePacket(c *Client, p pk.Packet) error {
 
 func handleWindowItemsPacket(c *Client, p pk.Packet) error {
 	var pkt ptypes.WindowItems
-	if err := pkt.Decode(p); err != nil {
+	if _, err := pkt.ReadFrom(bytes.NewReader(p.Data)); err != nil {
 		return err
 	}
 

bot/login.go

@@ -62,34 +62,12 @@ type encryptionRequest struct {
 	VerifyToken []byte
 }
 
-func (e *encryptionRequest) Decode(r pk.DecodeReader) error {
+func (e *encryptionRequest) ReadFrom(r io.Reader) (int64, error) {
-	var serverID pk.String
+	return pk.Tuple{
-	if err := serverID.Decode(r); err != nil {
+		(*pk.String)(&e.ServerID),
-		return err
+		(*pk.ByteArray)(&e.PublicKey),
-	}
+		(*pk.ByteArray)(&e.VerifyToken),
-
+	}.ReadFrom(r)
-	var publicKeyLength, verifyTokenLength pk.VarInt
-
-	if err := publicKeyLength.Decode(r); err != nil {
-		return err
-	}
-	publicKey, err := pk.ReadNBytes(r, int(publicKeyLength))
-	if err != nil {
-		return err
-	}
-
-	if err := verifyTokenLength.Decode(r); err != nil {
-		return err
-	}
-	verifyToken, err := pk.ReadNBytes(r, int(verifyTokenLength))
-	if err != nil {
-		return err
-	}
-
-	e.ServerID = string(serverID)
-	e.PublicKey = publicKey
-	e.VerifyToken = verifyToken
-	return nil
 }
 
 // authDigest computes a special SHA-1 digest required for Minecraft web
@@ -216,14 +194,9 @@ func genEncryptionKeyResponse(shareSecret, publicKey, verifyToken []byte) (erp p
 		err = fmt.Errorf("encryption verfy tokenfail: %v", err)
 		return
 	}
-	var data []byte
+	return pk.Marshal(
-	data = append(data, pk.VarInt(int32(len(cryptPK))).Encode()...)
+		0x01,
-	data = append(data, cryptPK...)
+		pk.ByteArray(cryptPK),
-	data = append(data, pk.VarInt(int32(len(verifyT))).Encode()...)
+		pk.ByteArray(verifyT),
-	data = append(data, verifyT...)
+	), nil
-	erp = pk.Packet{
-		ID:   0x01,
-		Data: data,
-	}
-	return
 }

bot/world/chunk.go

@@ -3,6 +3,7 @@ package world
 import (
 	"bytes"
 	"fmt"
+	"io"
 	"math"
 
 	"github.com/Tnze/go-mc/data/block"
@@ -41,13 +42,13 @@ func perBits(bpb byte) uint {
 	}
 }
 
-func readSection(data pk.DecodeReader) (s Section, err error) {
+func readSection(data io.Reader) (s Section, err error) {
 	var nonAirBlockCount pk.Short
-	if err := nonAirBlockCount.Decode(data); err != nil {
+	if _, err := nonAirBlockCount.ReadFrom(data); err != nil {
 		return nil, fmt.Errorf("block count: %w", err)
 	}
 	var bpb pk.UnsignedByte
-	if err := bpb.Decode(data); err != nil {
+	if _, err := bpb.ReadFrom(data); err != nil {
 		return nil, fmt.Errorf("bits per block: %w", err)
 	}
 	// If bpb values greater than or equal to 9, use directSection.
@@ -57,14 +58,14 @@ func readSection(data pk.DecodeReader) (s Section, err error) {
 	if bpb <= maxPaletteBits {
 		// read palettes
 		var length pk.VarInt
-		if err := length.Decode(data); err != nil {
+		if _, err := length.ReadFrom(data); err != nil {
 			return nil, fmt.Errorf("palette length: %w", err)
 		}
 		palettes = make([]BlockStatus, length)
 		palettesIndex = make(map[BlockStatus]int, length)
 		for i := 0; i < int(length); i++ {
 			var v pk.VarInt
-			if err := v.Decode(data); err != nil {
+			if _, err := v.ReadFrom(data); err != nil {
 				return nil, fmt.Errorf("read palettes[%d] error: %w", i, err)
 			}
 			palettes[i] = BlockStatus(v)
@@ -74,7 +75,7 @@ func readSection(data pk.DecodeReader) (s Section, err error) {
 
 	// read data array
 	var dataLen pk.VarInt
-	if err := dataLen.Decode(data); err != nil {
+	if _, err := dataLen.ReadFrom(data); err != nil {
 		return nil, fmt.Errorf("read data array length error: %w", err)
 	}
 	if int(dataLen) < 16*16*16*int(bpb)/64 {
@@ -83,7 +84,7 @@ func readSection(data pk.DecodeReader) (s Section, err error) {
 	dataArray := make([]uint64, dataLen)
 	for i := 0; i < int(dataLen); i++ {
 		var v pk.Long
-		if err := v.Decode(data); err != nil {
+		if _, err := v.ReadFrom(data); err != nil {
 			return nil, fmt.Errorf("read dataArray[%d] error: %w", i, err)
 		}
 		dataArray[i] = uint64(v)

bot/world/entity/entity.go

@@ -1,11 +1,10 @@
 package entity
 
 import (
-	"bytes"
+	"io"
 
 	"github.com/Tnze/go-mc/data/entity"
 	item "github.com/Tnze/go-mc/data/item"
-	"github.com/Tnze/go-mc/nbt"
 	pk "github.com/Tnze/go-mc/net/packet"
 	"github.com/google/uuid"
 )
@@ -49,53 +48,48 @@ type Slot struct {
 	Present bool
 	ItemID  item.ID
 	Count   int8
-	NBT     interface{}
+	NBT     pk.NBT
+}
+
+type SlotNBT struct {
+	data interface{}
 }
 
 //Decode implement packet.FieldDecoder interface
-func (s *Slot) Decode(r pk.DecodeReader) error {
+func (s *Slot) ReadFrom(r io.Reader) (int64, error) {
-	if err := (*pk.Boolean)(&s.Present).Decode(r); err != nil {
-		return err
-	}
-	if s.Present {
 	var itemID pk.VarInt
-		if err := itemID.Decode(r); err != nil {
+	n, err := pk.Tuple{
-			return err
+		(*pk.Boolean)(&s.Present),
+		pk.Opt{
+			Has: (*pk.Boolean)(&s.Present),
+			Field: pk.Tuple{
+				&itemID,
+				(*pk.Byte)(&s.Count),
+				&s.NBT,
+			},
+		},
+	}.ReadFrom(r)
+	if err != nil {
+		return n, err
 	}
 	s.ItemID = item.ID(itemID)
-		if err := (*pk.Byte)(&s.Count).Decode(r); err != nil {
+	return n, nil
-			return err
-		}
-		if err := nbt.NewDecoder(r).Decode(&s.NBT); err != nil {
-			return err
-		}
-	}
-	return nil
 }
 
-func (s Slot) Encode() []byte {
+func (s Slot) WriteTo(w io.Writer) (int64, error) {
-	if !s.Present {
+	return pk.Tuple{
-		return pk.Boolean(false).Encode()
+		pk.Boolean(s.Present),
-	}
+		pk.Opt{
-
+			Has: (*pk.Boolean)(&s.Present),
-	var b bytes.Buffer
+			Field: pk.Tuple{
-	b.Write(pk.Boolean(true).Encode())
+				pk.VarInt(s.ItemID),
-	b.Write(pk.VarInt(s.ItemID).Encode())
+				pk.Byte(s.Count),
-	b.Write(pk.Byte(s.Count).Encode())
+				s.NBT,
-
+			},
-	if s.NBT != nil {
+		},
-		if err := nbt.NewEncoder(&b).Encode(s.NBT); err != nil {
+	}.WriteTo(w)
-			panic(err)
-		}
-	} else {
-		if _, err := b.Write([]byte{nbt.TagEnd}); err != nil {
-			panic(err)
-		}
-	}
-
-	return b.Bytes()
 }
 
 func (s Slot) String() string {
-	return item.ByID[item.ID(s.ItemID)].DisplayName
+	return item.ByID[s.ItemID].DisplayName
 }

chat/chatMsg.go

@@ -51,22 +51,23 @@ func (m *Message) UnmarshalJSON(jsonMsg []byte) (err error) {
 }
 
 //Decode for a ChatMsg packet
-func (m *Message) Decode(r pk.DecodeReader) error {
+func (m *Message) ReadFrom(r io.Reader) (int64, error) {
 	var Len pk.VarInt
-	if err := Len.Decode(r); err != nil {
+	if n, err := Len.ReadFrom(r); err != nil {
-		return err
+		return n, err
 	}
-
+	lr := &io.LimitedReader{R: r, N: int64(Len)}
-	return json.NewDecoder(io.LimitReader(r, int64(Len))).Decode(m)
+	err := json.NewDecoder(lr).Decode(m)
+	return int64(Len) - lr.N, err
 }
 
 //Encode for a ChatMsg packet
-func (m Message) Encode() []byte {
+func (m Message) WriteTo(w io.Writer) (int64, error) {
 	code, err := json.Marshal(m)
 	if err != nil {
 		panic(err)
 	}
-	return pk.String(code).Encode()
+	return pk.String(code).WriteTo(w)
 }
 
 func (m *Message) Append(extraMsg ...Message) {

chat/chatMsg_test.go

@@ -101,10 +101,11 @@ func TestChatMsgClearString(t *testing.T) {
 }
 
 func TestMessage_Encode(t *testing.T) {
-	codeMsg := chat.Message{Translate: "multiplayer.disconnect.server_full"}.Encode()
+	var codeMsg bytes.Buffer
+	_, _ = chat.Message{Translate: "multiplayer.disconnect.server_full"}.WriteTo(&codeMsg)
 
 	var msg pk.Chat
-	if err := msg.Decode(bytes.NewReader(codeMsg)); err != nil {
+	if _, err := msg.ReadFrom(&codeMsg); err != nil {
 		t.Errorf("decode message fail: %v", err)
 	}
 

cmd/daze/daze.go

@@ -65,7 +65,7 @@ func onPluginMessage(channel string, data []byte) error {
 	switch channel {
 	case "minecraft:brand":
 		var brand pk.String
-		if err := brand.Decode(bytes.NewReader(data)); err != nil {
+		if _, err := brand.ReadFrom(bytes.NewReader(data)); err != nil {
 			return err
 		}
 		log.Println("Server brand is:", brand)

net/conn.go

@@ -85,8 +85,7 @@ func (c *Conn) ReadPacket(p *pk.Packet) error {
 
 //WritePacket write a Packet to Conn.
 func (c *Conn) WritePacket(p pk.Packet) error {
-	_, err := c.Write(p.Pack(c.threshold))
+	return p.Pack(c, c.threshold)
-	return err
 }
 
 // SetCipher load the decode/encode stream to this Conn

net/packet/builder.go

@@ -8,7 +8,10 @@ type Builder struct {
 
 func (p *Builder) WriteField(fields ...FieldEncoder) {
 	for _, f := range fields {
-		p.buf.Write(f.Encode())
+		_, err := f.WriteTo(&p.buf)
+		if err != nil {
+			panic(err)
+		}
 	}
 }
 

net/packet/packet.go

@@ -15,20 +15,18 @@ type Packet struct {
 
 //Marshal generate Packet with the ID and Fields
 func Marshal(id int32, fields ...FieldEncoder) (pk Packet) {
-	pk.ID = id
+	var pb Builder
-
 	for _, v := range fields {
-		pk.Data = append(pk.Data, v.Encode()...)
+		pb.WriteField(v)
 	}
-
+	return pb.Packet(id)
-	return
 }
 
 //Scan decode the packet and fill data into fields
 func (p Packet) Scan(fields ...FieldDecoder) error {
 	r := bytes.NewReader(p.Data)
 	for _, v := range fields {
-		err := v.Decode(r)
+		_, err := v.ReadFrom(r)
 		if err != nil {
 			return err
 		}
@@ -37,34 +35,48 @@ func (p Packet) Scan(fields ...FieldDecoder) error {
 }
 
 // Pack 打包一个数据包
-func (p *Packet) Pack(threshold int) (pack []byte) {
+func (p *Packet) Pack(w io.Writer, threshold int) error {
-	d := append(VarInt(p.ID).Encode(), p.Data...)
+	var content bytes.Buffer
+	if _, err := VarInt(p.ID).WriteTo(&content); err != nil {
+		panic(err)
+	}
+	if _, err := content.Write(p.Data); err != nil {
+		panic(err)
+	}
 	if threshold > 0 { //是否启用了压缩
-		if len(d) > threshold { //是否需要压缩
+		Len := content.Len()
-			Len := len(d)
+		var VarLen bytes.Buffer
-			VarLen := VarInt(Len).Encode()
+		if _, err := VarInt(Len).WriteTo(&VarLen); err != nil {
-			d = compress(d)
+			panic(err)
-
+		}
-			pack = append(pack, VarInt(len(VarLen)+len(d)).Encode()...)
+		if _, err := VarInt(VarLen.Len() + Len).WriteTo(w); err != nil {
-			pack = append(pack, VarLen...)
+			return err
-			pack = append(pack, d...)
+		}
-		} else {
+		if Len > threshold { //是否需要压缩
-			pack = append(pack, VarInt(int32(len(d)+1)).Encode()...)
+			compress(&content)
-			pack = append(pack, 0x00)
+		}
-			pack = append(pack, d...)
+		if _, err := VarLen.WriteTo(w); err != nil {
+			return err
+		}
+		if _, err := content.WriteTo(w); err != nil {
+			return err
 		}
 	} else {
-		pack = append(pack, VarInt(int32(len(d))).Encode()...) //len
+		if _, err := VarInt(content.Len()).WriteTo(w); err != nil {
-		pack = append(pack, d...)
+			return err
+		}
+		if _, err := content.WriteTo(w); err != nil {
+			return err
+		}
 	}
 
-	return
+	return nil
 }
 
 // UnPack in-place decompression a packet
-func (p *Packet) UnPack(r DecodeReader, threshold int) error {
+func (p *Packet) UnPack(r io.Reader, threshold int) error {
 	var length VarInt
-	if err := length.Decode(r); err != nil {
+	if _, err := length.ReadFrom(r); err != nil {
 		return err
 	}
 	if length < 1 {
@@ -84,7 +96,7 @@ func (p *Packet) UnPack(r DecodeReader, threshold int) error {
 	}
 
 	var packetID VarInt
-	if err := packetID.Decode(buf); err != nil {
+	if _, err := packetID.ReadFrom(buf); err != nil {
 		return fmt.Errorf("read packet id fail: %v", err)
 	}
 	p.ID = int32(packetID)
@@ -97,7 +109,7 @@ func unCompress(data *bytes.Buffer) error {
 	reader := bytes.NewReader(data.Bytes())
 
 	var sizeUncompressed VarInt
-	if err := sizeUncompressed.Decode(reader); err != nil {
+	if _, err := sizeUncompressed.ReadFrom(reader); err != nil {
 		return err
 	}
 
@@ -121,14 +133,15 @@ func unCompress(data *bytes.Buffer) error {
 }
 
 // compress 压缩数据
-func compress(data []byte) []byte {
+func compress(data *bytes.Buffer) {
 	var b bytes.Buffer
 	w := zlib.NewWriter(&b)
-	if _, err := w.Write(data); err != nil {
+	if _, err := data.WriteTo(w); err != nil {
 		panic(err)
 	}
 	if err := w.Close(); err != nil {
 		panic(err)
 	}
-	return b.Bytes()
+	*data = b
+	return
 }

net/packet/packet_test.go

@@ -20,9 +20,15 @@ var PackedVarInts = [][]byte{
 }
 
 func TestPackVarInt(t *testing.T) {
+	var buf bytes.Buffer
 	for i, v := range VarInts {
-		p := v.Encode()
+		buf.Reset()
-		if !bytes.Equal(p, PackedVarInts[i]) {
+		if n, err := v.WriteTo(&buf); err != nil {
+			t.Fatalf("Write to bytes.Buffer should never fail: %v", err)
+		} else if n != int64(buf.Len()) {
+			t.Errorf("Number of byte returned by WriteTo should equal to buffer.Len()")
+		}
+		if p := buf.Bytes(); !bytes.Equal(p, PackedVarInts[i]) {
 			t.Errorf("pack int %d should be \"% x\", get \"% x\"", v, PackedVarInts[i], p)
 		}
 	}
@@ -30,7 +36,7 @@ func TestPackVarInt(t *testing.T) {
 func TestUnpackVarInt(t *testing.T) {
 	for i, v := range PackedVarInts {
 		var vi VarInt
-		if err := vi.Decode(bytes.NewReader(v)); err != nil {
+		if _, err := vi.ReadFrom(bytes.NewReader(v)); err != nil {
 			t.Errorf("unpack \"% x\" error: %v", v, err)
 		}
 		if vi != VarInts[i] {
@@ -42,7 +48,7 @@ func TestUnpackVarInt(t *testing.T) {
 func TestUnpackVarInt_TooLongData(t *testing.T) {
 	var vi VarInt
 	var data = []byte{0x80, 0x80, 0x80, 0x80, 0x80, 0x80, 0x01}
-	if err := vi.Decode(bytes.NewReader(data)); err != nil {
+	if _, err := vi.ReadFrom(bytes.NewReader(data)); err != nil {
 		t.Logf("unpack \"% x\" error: %v", data, err)
 	} else {
 		t.Errorf("unpack \"% x\" should be error, get %d", data, vi)
@@ -76,7 +82,7 @@ func TestPackVarLong(t *testing.T) {
 func TestUnpackVarLong(t *testing.T) {
 	for i, v := range PackedVarLongs {
 		var vi VarLong
-		if err := vi.Decode(bytes.NewReader(v)); err != nil {
+		if _, err := vi.ReadFrom(bytes.NewReader(v)); err != nil {
 			t.Errorf("unpack \"% x\" error: %v", v, err)
 		}
 		if vi != VarLongs[i] {

net/packet/types.go

@@ -18,20 +18,10 @@ type Field interface {
 }
 
 // A FieldEncoder can be encode as minecraft protocol used.
-type FieldEncoder interface {
+type FieldEncoder io.WriterTo
-	Encode() []byte
-}
 
 // A FieldDecoder can Decode from minecraft protocol
-type FieldDecoder interface {
+type FieldDecoder io.ReaderFrom
-	Decode(r DecodeReader) error
-}
-
-//DecodeReader is both io.Reader and io.ByteReader
-type DecodeReader interface {
-	io.ByteReader
-	io.Reader
-}
 
 type (
 	//Boolean of True is encoded as 0x01, false as 0x00.
@@ -71,7 +61,7 @@ type (
 	}
 
 	//Angle is rotation angle in steps of 1/256 of a full turn
-	Angle int8
+	Angle Byte
 
 	//UUID encoded as an unsigned 128-bit integer
 	UUID uuid.UUID
@@ -86,174 +76,190 @@ type (
 	ByteArray []byte
 )
 
-//ReadNBytes read N bytes from bytes.Reader
+const MaxVarIntLen = 5
-func ReadNBytes(r DecodeReader, n int) (bs []byte, err error) {
+const MaxVarLongLen = 10
-	bs = make([]byte, n)
-	for i := 0; i < n; i++ {
-		bs[i], err = r.ReadByte()
-		if err != nil {
-			return
-		}
-	}
-	return
-}
 
 //Encode a Boolean
-func (b Boolean) Encode() []byte {
+func (b Boolean) WriteTo(w io.Writer) (n int64, err error) {
+	var nn int
 	if b {
-		return []byte{0x01}
+		nn, err = w.Write([]byte{0x01})
 	}
-	return []byte{0x00}
+	nn, err = w.Write([]byte{0x00})
+	return int64(nn), err
 }
 
 //Decode a Boolean
-func (b *Boolean) Decode(r DecodeReader) error {
+func (b *Boolean) ReadFrom(r io.Reader) (n int64, err error) {
-	v, err := r.ReadByte()
+	v, err := readByte(r)
 	if err != nil {
-		return err
+		return 1, err
 	}
 
-	*b = Boolean(v != 0)
+	*b = v != 0
-	return nil
+	return 1, nil
 }
 
 // Encode a String
-func (s String) Encode() (p []byte) {
+func (s String) WriteTo(w io.Writer) (int64, error) {
-	byteString := []byte(s)
+	byteStr := []byte(s)
-	p = append(p, VarInt(len(byteString)).Encode()...) //len
+	n1, err := VarInt(len(byteStr)).WriteTo(w)
-	p = append(p, byteString...)                       //data
+	if err != nil {
-	return
+		return n1, err
+	}
+	n2, err := w.Write(byteStr)
+	return n1 + int64(n2), err
 }
 
 //Decode a String
-func (s *String) Decode(r DecodeReader) error {
+func (s *String) ReadFrom(r io.Reader) (n int64, err error) {
 	var l VarInt //String length
-	if err := l.Decode(r); err != nil {
-		return err
-	}
 
-	bs, err := ReadNBytes(r, int(l))
+	nn, err := l.ReadFrom(r)
 	if err != nil {
-		return err
+		return nn, err
 	}
+	n += nn
+
+	bs := make([]byte, l)
+	if _, err := io.ReadFull(r, bs); err != nil {
+		return n, err
+	}
+	n += int64(l)
 
 	*s = String(bs)
-	return nil
+	return n, nil
+}
+
+// readByte read one byte from io.Reader
+func readByte(r io.Reader) (byte, error) {
+	if r, ok := r.(io.ByteReader); ok {
+		return r.ReadByte()
+	}
+	var v [1]byte
+	_, err := io.ReadFull(r, v[:])
+	return v[0], err
 }
 
 //Encode a Byte
-func (b Byte) Encode() []byte {
+func (b Byte) WriteTo(w io.Writer) (n int64, err error) {
-	return []byte{byte(b)}
+	nn, err := w.Write([]byte{byte(b)})
+	return int64(nn), err
 }
 
 //Decode a Byte
-func (b *Byte) Decode(r DecodeReader) error {
+func (b *Byte) ReadFrom(r io.Reader) (n int64, err error) {
-	v, err := r.ReadByte()
+	v, err := readByte(r)
 	if err != nil {
-		return err
+		return 0, err
 	}
 	*b = Byte(v)
-	return nil
+	return 1, nil
 }
 
 //Encode a UnsignedByte
-func (ub UnsignedByte) Encode() []byte {
+func (u UnsignedByte) WriteTo(w io.Writer) (n int64, err error) {
-	return []byte{byte(ub)}
+	nn, err := w.Write([]byte{byte(u)})
+	return int64(nn), err
 }
 
 //Decode a UnsignedByte
-func (ub *UnsignedByte) Decode(r DecodeReader) error {
+func (u *UnsignedByte) ReadFrom(r io.Reader) (n int64, err error) {
-	v, err := r.ReadByte()
+	v, err := readByte(r)
 	if err != nil {
-		return err
+		return 0, err
 	}
-	*ub = UnsignedByte(v)
+	*u = UnsignedByte(v)
-	return nil
+	return 1, nil
 }
 
 // Encode a Signed Short
-func (s Short) Encode() []byte {
+func (s Short) WriteTo(w io.Writer) (int64, error) {
 	n := uint16(s)
-	return []byte{
+	nn, err := w.Write([]byte{byte(n >> 8), byte(n)})
-		byte(n >> 8),
+	return int64(nn), err
-		byte(n),
-	}
 }
 
 //Decode a Short
-func (s *Short) Decode(r DecodeReader) error {
+func (s *Short) ReadFrom(r io.Reader) (n int64, err error) {
-	bs, err := ReadNBytes(r, 2)
+	var bs [2]byte
-	if err != nil {
+	if nn, err := io.ReadFull(r, bs[:]); err != nil {
-		return err
+		return int64(nn), err
+	} else {
+		n += int64(nn)
 	}
 
 	*s = Short(int16(bs[0])<<8 | int16(bs[1]))
-	return nil
+	return
 }
 
 // Encode a Unsigned Short
-func (us UnsignedShort) Encode() []byte {
+func (us UnsignedShort) WriteTo(w io.Writer) (int64, error) {
 	n := uint16(us)
-	return []byte{
+	nn, err := w.Write([]byte{byte(n >> 8), byte(n)})
-		byte(n >> 8),
+	return int64(nn), err
-		byte(n),
-	}
 }
 
 //Decode a UnsignedShort
-func (us *UnsignedShort) Decode(r DecodeReader) error {
+func (us *UnsignedShort) ReadFrom(r io.Reader) (n int64, err error) {
-	bs, err := ReadNBytes(r, 2)
+	var bs [2]byte
-	if err != nil {
+	if nn, err := io.ReadFull(r, bs[:]); err != nil {
-		return err
+		return int64(nn), err
+	} else {
+		n += int64(nn)
 	}
 
 	*us = UnsignedShort(int16(bs[0])<<8 | int16(bs[1]))
-	return nil
+	return
 }
 
 // Encode a Int
-func (i Int) Encode() []byte {
+func (i Int) WriteTo(w io.Writer) (int64, error) {
 	n := uint32(i)
-	return []byte{
+	nn, err := w.Write([]byte{byte(n >> 24), byte(n >> 16), byte(n >> 8), byte(n)})
-		byte(n >> 24), byte(n >> 16),
+	return int64(nn), err
-		byte(n >> 8), byte(n),
-	}
 }
 
 //Decode a Int
-func (i *Int) Decode(r DecodeReader) error {
+func (i *Int) ReadFrom(r io.Reader) (n int64, err error) {
-	bs, err := ReadNBytes(r, 4)
+	var bs [4]byte
-	if err != nil {
+	if nn, err := io.ReadFull(r, bs[:]); err != nil {
-		return err
+		return int64(nn), err
+	} else {
+		n += int64(nn)
 	}
 
 	*i = Int(int32(bs[0])<<24 | int32(bs[1])<<16 | int32(bs[2])<<8 | int32(bs[3]))
-	return nil
+	return
 }
 
 // Encode a Long
-func (l Long) Encode() []byte {
+func (l Long) WriteTo(w io.Writer) (int64, error) {
 	n := uint64(l)
-	return []byte{
+	nn, err := w.Write([]byte{
 		byte(n >> 56), byte(n >> 48), byte(n >> 40), byte(n >> 32),
 		byte(n >> 24), byte(n >> 16), byte(n >> 8), byte(n),
-	}
+	})
+	return int64(nn), err
 }
 
 //Decode a Long
-func (l *Long) Decode(r DecodeReader) error {
+func (l *Long) ReadFrom(r io.Reader) (n int64, err error) {
-	bs, err := ReadNBytes(r, 8)
+	var bs [8]byte
-	if err != nil {
+	if nn, err := io.ReadFull(r, bs[:]); err != nil {
-		return err
+		return int64(nn), err
+	} else {
+		n += int64(nn)
 	}
 
 	*l = Long(int64(bs[0])<<56 | int64(bs[1])<<48 | int64(bs[2])<<40 | int64(bs[3])<<32 |
 		int64(bs[4])<<24 | int64(bs[5])<<16 | int64(bs[6])<<8 | int64(bs[7]))
-	return nil
+	return
 }
 
 //Encode a VarInt
-func (v VarInt) Encode() (vi []byte) {
+func (v VarInt) WriteTo(w io.Writer) (n int64, err error) {
+	var vi = make([]byte, 0, MaxVarIntLen)
 	num := uint32(v)
 	for {
 		b := num & 0x7F
@@ -266,29 +272,28 @@ func (v VarInt) Encode() (vi []byte) {
 			break
 		}
 	}
-	return
+	nn, err := w.Write(vi)
+	return int64(nn), err
 }
 
 //Decode a VarInt
-func (v *VarInt) Decode(r DecodeReader) error {
+func (v *VarInt) ReadFrom(r io.Reader) (n int64, err error) {
-	var n uint32
+	var V uint32
-	for i := 0; ; i++ { //读数据前的长度标记
+	for sec := byte(0x80); sec&0x80 != 0; n++ {
-		sec, err := r.ReadByte()
+		if n > MaxVarIntLen {
+			return n, errors.New("VarInt is too big")
+		}
+
+		sec, err = readByte(r)
 		if err != nil {
-			return err
+			return n, err
 		}
 
-		n |= uint32(sec&0x7F) << uint32(7*i)
+		V |= uint32(sec&0x7F) << uint32(7*n)
-
-		if i >= 5 {
-			return errors.New("VarInt is too big")
-		} else if sec&0x80 == 0 {
-			break
-		}
 	}
 
-	*v = VarInt(n)
+	*v = VarInt(V)
-	return nil
+	return
 }
 
 //Encode a VarLong
@@ -309,44 +314,44 @@ func (v VarLong) Encode() (vi []byte) {
 }
 
 //Decode a VarLong
-func (v *VarLong) Decode(r DecodeReader) error {
+func (v *VarLong) ReadFrom(r io.Reader) (n int64, err error) {
-	var n uint64
+	var V uint64
-	for i := 0; ; i++ { //读数据前的长度标记
+	for sec := byte(0x80); sec&0x80 != 0; n++ {
-		sec, err := r.ReadByte()
+		if n >= MaxVarLongLen {
+			return n, errors.New("VarLong is too big")
+		}
+		sec, err = readByte(r)
 		if err != nil {
-			return err
+			return
 		}
 
-		n |= uint64(sec&0x7F) << uint64(7*i)
+		V |= uint64(sec&0x7F) << uint64(7*n)
-
-		if i >= 10 {
-			return errors.New("VarLong is too big")
-		} else if sec&0x80 == 0 {
-			break
-		}
 	}
 
-	*v = VarLong(n)
+	*v = VarLong(V)
-	return nil
+	return
 }
 
 //Encode a Position
-func (p Position) Encode() []byte {
+func (p Position) WriteTo(w io.Writer) (n int64, err error) {
-	b := make([]byte, 8)
+	var b [8]byte
 	position := uint64(p.X&0x3FFFFFF)<<38 | uint64((p.Z&0x3FFFFFF)<<12) | uint64(p.Y&0xFFF)
 	for i := 7; i >= 0; i-- {
 		b[i] = byte(position)
 		position >>= 8
 	}
-	return b
+	nn, err := w.Write(b[:])
+	return int64(nn), err
 }
 
 // Decode a Position
-func (p *Position) Decode(r DecodeReader) error {
+func (p *Position) ReadFrom(r io.Reader) (n int64, err error) {
 	var v Long
-	if err := v.Decode(r); err != nil {
+	nn, err := v.ReadFrom(r)
-		return err
+	if err != nil {
+		return nn, err
 	}
+	n += nn
 
 	x := int(v >> 38)
 	y := int(v & 0xFFF)
@@ -364,88 +369,111 @@ func (p *Position) Decode(r DecodeReader) error {
 	}
 
 	p.X, p.Y, p.Z = x, y, z
-	return nil
+	return
 }
 
-//Decodes an Angle
+// ToDeg convert Angle to Degree
-func (b *Angle) Decode(r DecodeReader) error {
+func (a Angle) ToDeg() float64 {
-	v, err := r.ReadByte()
+	return 360 * float64(a) / 256
-	if err != nil {
+}
-		return err
+
-	}
+// ToRad convert Angle to Radian
-	*b = Angle(v)
+func (a Angle) ToRad() float64 {
-	return nil
+	return 2 * math.Pi * float64(a) / 256
+}
+
+func (a Angle) WriteTo(w io.Writer) (int64, error) {
+	return Byte(a).WriteTo(w)
+}
+
+func (a *Angle) ReadFrom(r io.Reader) (int64, error) {
+	return (*Byte)(a).ReadFrom(r)
 }
 
 //Encode a Float
-func (f Float) Encode() []byte {
+func (f Float) WriteTo(w io.Writer) (n int64, err error) {
-	return Int(math.Float32bits(float32(f))).Encode()
+	return Int(math.Float32bits(float32(f))).WriteTo(w)
 }
 
 // Decode a Float
-func (f *Float) Decode(r DecodeReader) error {
+func (f *Float) ReadFrom(r io.Reader) (n int64, err error) {
 	var v Int
-	if err := v.Decode(r); err != nil {
+
-		return err
+	n, err = v.ReadFrom(r)
+	if err != nil {
+		return
 	}
 
 	*f = Float(math.Float32frombits(uint32(v)))
-	return nil
+	return
 }
 
 //Encode a Double
-func (d Double) Encode() []byte {
+func (d Double) WriteTo(w io.Writer) (n int64, err error) {
-	return Long(math.Float64bits(float64(d))).Encode()
+	return Long(math.Float64bits(float64(d))).WriteTo(w)
 }
 
 // Decode a Double
-func (d *Double) Decode(r DecodeReader) error {
+func (d *Double) ReadFrom(r io.Reader) (n int64, err error) {
 	var v Long
-	if err := v.Decode(r); err != nil {
+	n, err = v.ReadFrom(r)
-		return err
+	if err != nil {
+		return
 	}
 
 	*d = Double(math.Float64frombits(uint64(v)))
-	return nil
+	return
 }
 
 // Encode a NBT
-func (n NBT) Encode() []byte {
+func (n *NBT) WriteTo(w io.Writer) (int64, error) {
 	var buf bytes.Buffer
 	if err := nbt.NewEncoder(&buf).Encode(n.V); err != nil {
 		panic(err)
 	}
-	return buf.Bytes()
+	return buf.WriteTo(w)
 }
 
 // Decode a NBT
-func (n NBT) Decode(r DecodeReader) error {
+func (n *NBT) ReadFrom(r io.Reader) (int64, error) {
-	return nbt.NewDecoder(r).Decode(n.V)
+	// LimitReader is used to count reader length
+	lr := &io.LimitedReader{R: r, N: math.MaxInt64}
+	err := nbt.NewDecoder(lr).Decode(n.V)
+	return math.MaxInt64 - lr.N, err
 }
 
 // Encode a ByteArray
-func (b ByteArray) Encode() []byte {
+func (b ByteArray) WriteTo(w io.Writer) (n int64, err error) {
-	return append(VarInt(len(b)).Encode(), b...)
+	n1, err := VarInt(len(b)).WriteTo(w)
+	if err != nil {
+		return n1, err
+	}
+	n2, err := w.Write(b)
+	return n1 + int64(n2), err
 }
 
 // Decode a ByteArray
-func (b *ByteArray) Decode(r DecodeReader) error {
+func (b *ByteArray) ReadFrom(r io.Reader) (n int64, err error) {
 	var Len VarInt
-	if err := Len.Decode(r); err != nil {
+	n1, err := Len.ReadFrom(r)
-		return err
+	if err != nil {
+		return n1, err
 	}
-	*b = make([]byte, Len)
+	buf := bytes.NewBuffer(*b)
-	_, err := r.Read(*b)
+	buf.Reset()
-	return err
+	n2, err := io.CopyN(buf, r, int64(Len))
+	*b = buf.Bytes()
+	return n1 + n2, err
 }
 
 // Encode a UUID
-func (u UUID) Encode() []byte {
+func (u UUID) WriteTo(w io.Writer) (n int64, err error) {
-	return u[:]
+	nn, err := w.Write(u[:])
+	return int64(nn), err
 }
 
 // Decode a UUID
-func (u *UUID) Decode(r DecodeReader) error {
+func (u *UUID) ReadFrom(r io.Reader) (n int64, err error) {
-	_, err := io.ReadFull(r, (*u)[:])
+	nn, err := io.ReadFull(r, (*u)[:])
-	return err
+	return int64(nn), err
 }

net/packet/util.go

@@ -1,51 +1,84 @@
 package packet
 
 import (
+	"io"
 	"reflect"
 )
 
 type Ary struct {
-	Len Field
+	Len Field       // One of VarInt, VarLong, Int or Long
-	Ary interface{}
+	Ary interface{} // FieldEncoder, FieldDecoder or both (Field)
 }
 
-func (a Ary) Encode() (data []byte) {
+func (a Ary) WriteTo(r io.Writer) (n int64, err error) {
 	length := int(reflect.ValueOf(a.Len).Int())
 	array := reflect.ValueOf(a.Ary).Elem()
 	for i := 0; i < length; i++ {
 		elem := array.Index(i)
-		data = append(data, elem.Interface().(FieldEncoder).Encode()...)
+		nn, err := elem.Interface().(FieldEncoder).WriteTo(r)
+		n += nn
+		if err != nil {
+			return n, err
+		}
+	}
+	return n, nil
+}
+
+func (a Ary) ReadFrom(r io.Reader) (n int64, err error) {
+	length := int(reflect.ValueOf(a.Len).Int())
+	array := reflect.ValueOf(a.Ary).Elem()
+	for i := 0; i < length; i++ {
+		elem := array.Index(i)
+		nn, err := elem.Interface().(FieldDecoder).ReadFrom(r)
+		n += nn
+		if err != nil {
+			return n, err
+		}
+	}
+	return n, err
+}
+
+type Opt struct {
+	Has   *Boolean
+	Field interface{} // FieldEncoder, FieldDecoder or both (Field)
+}
+
+func (o Opt) WriteTo(w io.Writer) (int64, error) {
+	if *o.Has {
+		return o.Field.(FieldEncoder).WriteTo(w)
+	}
+	return 0, nil
+}
+
+func (o Opt) ReadFrom(r io.Reader) (int64, error) {
+	if *o.Has {
+		return o.Field.(FieldDecoder).ReadFrom(r)
+	}
+	return 0, nil
+}
+
+type Tuple []interface{} // FieldEncoder, FieldDecoder or both (Field)
+
+// WriteTo write Tuple to io.Writer, panic when any of filed don't implement FieldEncoder
+func (t Tuple) WriteTo(w io.Writer) (n int64, err error) {
+	for _, v := range t {
+		nn, err := v.(FieldEncoder).WriteTo(w)
+		if err != nil {
+			return n, err
+		}
+		n += nn
 	}
 	return
 }
 
-func (a Ary) Decode(r DecodeReader) error {
+// ReadFrom read Tuple from io.Reader, panic when any of field don't implement FieldDecoder
-	length := int(reflect.ValueOf(a.Len).Int())
+func (t Tuple) ReadFrom(r io.Reader) (n int64, err error) {
-	array := reflect.ValueOf(a.Ary).Elem()
+	for _, v := range t {
-	for i := 0; i < length; i++ {
+		nn, err := v.(FieldDecoder).ReadFrom(r)
-		elem := array.Index(i)
+		if err != nil {
-		if err := elem.Interface().(FieldDecoder).Decode(r); err != nil {
+			return n, err
-			return err
 		}
+		n += nn
 	}
-	return nil
+	return
-}
-
-type Opt struct {
-	Has   func() bool
-	Field interface{}
-}
-
-func (o Opt) Encode() []byte {
-	if o.Has() {
-		return nil
-	}
-	return o.Field.(FieldEncoder).Encode()
-}
-
-func (o Opt) Decode(r DecodeReader) error {
-	if o.Has() {
-		return nil
-	}
-	return o.Field.(FieldDecoder).Decode(r)
 }

net/ptypes/chunk.go

@@ -2,8 +2,8 @@
 package ptypes
 
 import (
-	"bytes"
+	"io"
-	"fmt"
+	"math"
 
 	"github.com/Tnze/go-mc/bot/world/entity"
 	"github.com/Tnze/go-mc/nbt"
@@ -17,96 +17,53 @@ type ChunkData struct {
 	PrimaryBitMask pk.VarInt
 	Heightmaps     struct{}
 	Biomes         biomesData
-	Data           chunkData
+	Data           pk.ByteArray
 	BlockEntities  blockEntities
 }
 
-func (p *ChunkData) Decode(pkt pk.Packet) error {
+func (p *ChunkData) ReadFrom(r io.Reader) (int64, error) {
-	r := bytes.NewReader(pkt.Data)
+	return pk.Tuple{
-	if err := p.X.Decode(r); err != nil {
+		&p.X,
-		return fmt.Errorf("decode X: %v", err)
+		&p.Z,
-	}
+		&p.FullChunk,
-	if err := p.Z.Decode(r); err != nil {
+		&p.PrimaryBitMask,
-		return fmt.Errorf("decode Z: %v", err)
+		&pk.NBT{V: &p.Heightmaps},
-	}
+		pk.Opt{Has: &p.FullChunk, Field: &p.Biomes},
-	if err := p.FullChunk.Decode(r); err != nil {
+		&p.Data,
-		return fmt.Errorf("full chunk: %v", err)
+		&p.BlockEntities,
-	}
+	}.ReadFrom(r)
-	if err := p.PrimaryBitMask.Decode(r); err != nil {
-		return fmt.Errorf("bit mask: %v", err)
-	}
-	if err := (pk.NBT{V: &p.Heightmaps}).Decode(r); err != nil {
-		return fmt.Errorf("heightmaps: %v", err)
-	}
-
-	// Biomes data is only present for full chunks.
-	if p.FullChunk {
-		if err := p.Biomes.Decode(r); err != nil {
-			return fmt.Errorf("heightmaps: %v", err)
-		}
-	}
-
-	if err := p.Data.Decode(r); err != nil {
-		return fmt.Errorf("data: %v", err)
-	}
-	if err := p.BlockEntities.Decode(r); err != nil {
-		return fmt.Errorf("block entities: %v", err)
-	}
-	return nil
 }
 
 type biomesData struct {
 	data []pk.VarInt
 }
 
-func (b *biomesData) Decode(r pk.DecodeReader) error {
+func (b *biomesData) ReadFrom(r io.Reader) (int64, error) {
-	var BiomesDataNums pk.VarInt // Number of Biomes Data
+	var n pk.VarInt // Number of Biomes Data
-	if err := BiomesDataNums.Decode(r); err != nil {
+	return pk.Tuple{
-		return err
+		&n, pk.Ary{Len: &n, Ary: []pk.VarInt{}},
-	}
+	}.ReadFrom(r)
-	b.data = make([]pk.VarInt, BiomesDataNums)
-
-	for i := 0; i < int(BiomesDataNums); i++ {
-		var d pk.VarInt
-		if err := d.Decode(r); err != nil {
-			return err
-		}
-		b.data[i] = d
-	}
-
-	return nil
 }
 
-type chunkData []byte
 type blockEntities []entity.BlockEntity
 
 // Decode implement net.packet.FieldDecoder
-func (c *chunkData) Decode(r pk.DecodeReader) error {
+func (b *blockEntities) ReadFrom(r io.Reader) (n int64, err error) {
-	var sz pk.VarInt
-	if err := sz.Decode(r); err != nil {
-		return err
-	}
-	*c = make([]byte, sz)
-	if _, err := r.Read(*c); err != nil {
-		return err
-	}
-	return nil
-}
-
-// Decode implement net.packet.FieldDecoder
-func (b *blockEntities) Decode(r pk.DecodeReader) error {
 	var sz pk.VarInt // Number of BlockEntities
-	if err := sz.Decode(r); err != nil {
+	if nn, err := sz.ReadFrom(r); err != nil {
-		return err
+		return nn, err
+	} else {
+		n += nn
 	}
 	*b = make(blockEntities, sz)
-	decoder := nbt.NewDecoder(r)
+	lr := &io.LimitedReader{R: r, N: math.MaxInt64}
+	d := nbt.NewDecoder(lr)
 	for i := 0; i < int(sz); i++ {
-		if err := decoder.Decode(&(*b)[i]); err != nil {
+		if err := d.Decode(&(*b)[i]); err != nil {
-			return err
+			return math.MaxInt64 - lr.N, err
 		}
 	}
-	return nil
+	return math.MaxInt64 - lr.N, nil
 }
 
 // TileEntityData describes a change to a tile entity.
@@ -116,13 +73,10 @@ type TileEntityData struct {
 	Data   entity.BlockEntity
 }
 
-func (p *TileEntityData) Decode(pkt pk.Packet) error {
+func (p *TileEntityData) ReadFrom(r io.Reader) (int64, error) {
-	r := bytes.NewReader(pkt.Data)
+	return pk.Tuple{
-	if err := p.Pos.Decode(r); err != nil {
+		&p.Pos,
-		return fmt.Errorf("position: %v", err)
+		&p.Action,
-	}
+		&pk.NBT{V: &p.Data},
-	if err := p.Action.Decode(r); err != nil {
+	}.ReadFrom(r)
-		return fmt.Errorf("action: %v", err)
-	}
-	return nbt.NewDecoder(r).Decode(&p.Data)
 }

net/ptypes/inventory.go

@@ -2,8 +2,8 @@
 package ptypes
 
 import (
-	"bytes"
 	"errors"
+	"io"
 
 	"github.com/Tnze/go-mc/bot/world/entity"
 	"github.com/Tnze/go-mc/chat"
@@ -35,24 +35,16 @@ type WindowItems struct {
 	Slots    []entity.Slot
 }
 
-func (p *WindowItems) Decode(pkt pk.Packet) error {
+func (p *WindowItems) ReadFrom(r io.Reader) (int64, error) {
-	r := bytes.NewReader(pkt.Data)
-	if err := p.WindowID.Decode(r); err != nil {
-		return err
-	}
-
 	var count pk.Short
-	if err := count.Decode(r); err != nil {
+	return pk.Tuple{
-		return err
+		&p.WindowID,
-	}
+		&count,
-
+		&pk.Ary{
-	p.Slots = make([]entity.Slot, int(count))
+			Len: &count,
-	for i := 0; i < int(count); i++ {
+			Ary: []entity.Slot{},
-		if err := p.Slots[i].Decode(r); err != nil && !errors.Is(err, nbt.ErrEND) {
+		},
-			return err
+	}.ReadFrom(r)
-		}
-	}
-	return nil
 }
 
 // OpenWindow is a clientbound packet which opens an inventory.

net/ptypes/misc.go

@@ -59,17 +59,18 @@ func (p *UpdateHealth) Decode(pkt pk.Packet) error {
 // PluginData encodes the custom data encoded in a plugin message.
 type PluginData []byte
 
-func (p PluginData) Encode() []byte {
+func (p PluginData) WriteTo(w io.Writer) (int64, error) {
-	return []byte(p)
+	n, err := w.Write(p)
+	return int64(n), err
 }
 
-func (p *PluginData) Decode(r pk.DecodeReader) error {
+func (p *PluginData) ReadFrom(r io.Reader) (int64, error) {
 	d, err := io.ReadAll(r)
 	if err != nil {
-		return err
+		return int64(len(d)), err
 	}
 	*p = d
-	return nil
+	return int64(len(d)), nil
 }
 
 // PluginMessage represents a packet with a customized payload.